diff options
Diffstat (limited to 'kernel')
70 files changed, 4230 insertions, 2312 deletions
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index d2b32ac27a39..35536d9c0964 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -223,3 +223,10 @@ endif config MUTEX_SPIN_ON_OWNER def_bool y depends on SMP && !DEBUG_MUTEXES + +config ARCH_USE_QUEUE_RWLOCK + bool + +config QUEUE_RWLOCK + def_bool y if ARCH_USE_QUEUE_RWLOCK + depends on SMP diff --git a/kernel/audit.c b/kernel/audit.c index f30106459a32..3ef2e0e797e8 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -424,6 +424,38 @@ static void kauditd_send_skb(struct sk_buff *skb) } /* + * kauditd_send_multicast_skb - send the skb to multicast userspace listeners + * + * This function doesn't consume an skb as might be expected since it has to + * copy it anyways. + */ +static void kauditd_send_multicast_skb(struct sk_buff *skb) +{ + struct sk_buff *copy; + struct audit_net *aunet = net_generic(&init_net, audit_net_id); + struct sock *sock = aunet->nlsk; + + if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG)) + return; + + /* + * The seemingly wasteful skb_copy() rather than bumping the refcount + * using skb_get() is necessary because non-standard mods are made to + * the skb by the original kaudit unicast socket send routine. The + * existing auditd daemon assumes this breakage. Fixing this would + * require co-ordinating a change in the established protocol between + * the kaudit kernel subsystem and the auditd userspace code. There is + * no reason for new multicast clients to continue with this + * non-compliance. + */ + copy = skb_copy(skb, GFP_KERNEL); + if (!copy) + return; + + nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL); +} + +/* * flush_hold_queue - empty the hold queue if auditd appears * * If auditd just started, drain the queue of messages already @@ -1076,10 +1108,22 @@ static void audit_receive(struct sk_buff *skb) mutex_unlock(&audit_cmd_mutex); } +/* Run custom bind function on netlink socket group connect or bind requests. */ +static int audit_bind(int group) +{ + if (!capable(CAP_AUDIT_READ)) + return -EPERM; + + return 0; +} + static int __net_init audit_net_init(struct net *net) { struct netlink_kernel_cfg cfg = { .input = audit_receive, + .bind = audit_bind, + .flags = NL_CFG_F_NONROOT_RECV, + .groups = AUDIT_NLGRP_MAX, }; struct audit_net *aunet = net_generic(net, audit_net_id); @@ -1901,10 +1945,10 @@ out: * audit_log_end - end one audit record * @ab: the audit_buffer * - * The netlink_* functions cannot be called inside an irq context, so - * the audit buffer is placed on a queue and a tasklet is scheduled to - * remove them from the queue outside the irq context. May be called in - * any context. + * netlink_unicast() cannot be called inside an irq context because it blocks + * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed + * on a queue and a tasklet is scheduled to remove them from the queue outside + * the irq context. May be called in any context. */ void audit_log_end(struct audit_buffer *ab) { @@ -1914,6 +1958,18 @@ void audit_log_end(struct audit_buffer *ab) audit_log_lost("rate limit exceeded"); } else { struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); + + kauditd_send_multicast_skb(ab->skb); + + /* + * The original kaudit unicast socket sends up messages with + * nlmsg_len set to the payload length rather than the entire + * message length. This breaks the standard set by netlink. + * The existing auditd daemon assumes this breakage. Fixing + * this would require co-ordinating a change in the established + * protocol between the kaudit kernel subsystem and the auditd + * userspace code. + */ nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; if (audit_pid) { diff --git a/kernel/auditsc.c b/kernel/auditsc.c index f251a5e8d17a..21eae3c05ec0 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -728,6 +728,22 @@ static enum audit_state audit_filter_task(struct task_struct *tsk, char **key) return AUDIT_BUILD_CONTEXT; } +static int audit_in_mask(const struct audit_krule *rule, unsigned long val) +{ + int word, bit; + + if (val > 0xffffffff) + return false; + + word = AUDIT_WORD(val); + if (word >= AUDIT_BITMASK_SIZE) + return false; + + bit = AUDIT_BIT(val); + + return rule->mask[word] & bit; +} + /* At syscall entry and exit time, this filter is called if the * audit_state is not low enough that auditing cannot take place, but is * also not high enough that we already know we have to write an audit @@ -745,11 +761,8 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk, rcu_read_lock(); if (!list_empty(list)) { - int word = AUDIT_WORD(ctx->major); - int bit = AUDIT_BIT(ctx->major); - list_for_each_entry_rcu(e, list, list) { - if ((e->rule.mask[word] & bit) == bit && + if (audit_in_mask(&e->rule, ctx->major) && audit_filter_rules(tsk, &e->rule, ctx, NULL, &state, false)) { rcu_read_unlock(); @@ -769,20 +782,16 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk, static int audit_filter_inode_name(struct task_struct *tsk, struct audit_names *n, struct audit_context *ctx) { - int word, bit; int h = audit_hash_ino((u32)n->ino); struct list_head *list = &audit_inode_hash[h]; struct audit_entry *e; enum audit_state state; - word = AUDIT_WORD(ctx->major); - bit = AUDIT_BIT(ctx->major); - if (list_empty(list)) return 0; list_for_each_entry_rcu(e, list, list) { - if ((e->rule.mask[word] & bit) == bit && + if (audit_in_mask(&e->rule, ctx->major) && audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) { ctx->current_state = state; return 1; diff --git a/kernel/capability.c b/kernel/capability.c index 84b2bbf443e7..a5cf13c018ce 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -424,23 +424,19 @@ bool capable(int cap) EXPORT_SYMBOL(capable); /** - * inode_capable - Check superior capability over inode + * capable_wrt_inode_uidgid - Check nsown_capable and uid and gid mapped * @inode: The inode in question * @cap: The capability in question * - * Return true if the current task has the given superior capability - * targeted at it's own user namespace and that the given inode is owned - * by the current user namespace or a child namespace. - * - * Currently we check to see if an inode is owned by the current - * user namespace by seeing if the inode's owner maps into the - * current user namespace. - * + * Return true if the current task has the given capability targeted at + * its own user namespace and that the given inode's uid and gid are + * mapped into the current user namespace. */ -bool inode_capable(const struct inode *inode, int cap) +bool capable_wrt_inode_uidgid(const struct inode *inode, int cap) { struct user_namespace *ns = current_user_ns(); - return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid); + return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid) && + kgid_has_mapping(ns, inode->i_gid); } -EXPORT_SYMBOL(inode_capable); +EXPORT_SYMBOL(capable_wrt_inode_uidgid); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index ceee0c54c6a4..70776aec2562 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -26,6 +26,8 @@ * distribution for more details. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/cgroup.h> #include <linux/cred.h> #include <linux/ctype.h> @@ -70,15 +72,6 @@ MAX_CFTYPE_NAME + 2) /* - * cgroup_tree_mutex nests above cgroup_mutex and protects cftypes, file - * creation/removal and hierarchy changing operations including cgroup - * creation, removal, css association and controller rebinding. This outer - * lock is needed mainly to resolve the circular dependency between kernfs - * active ref and cgroup_mutex. cgroup_tree_mutex nests above both. - */ -static DEFINE_MUTEX(cgroup_tree_mutex); - -/* * cgroup_mutex is the master lock. Any modification to cgroup or its * hierarchy must be performed while holding it. * @@ -99,16 +92,21 @@ static DECLARE_RWSEM(css_set_rwsem); #endif /* + * Protects cgroup_idr and css_idr so that IDs can be released without + * grabbing cgroup_mutex. + */ +static DEFINE_SPINLOCK(cgroup_idr_lock); + +/* * Protects cgroup_subsys->release_agent_path. Modifying it also requires * cgroup_mutex. Reading requires either cgroup_mutex or this spinlock. */ static DEFINE_SPINLOCK(release_agent_path_lock); -#define cgroup_assert_mutexes_or_rcu_locked() \ +#define cgroup_assert_mutex_or_rcu_locked() \ rcu_lockdep_assert(rcu_read_lock_held() || \ - lockdep_is_held(&cgroup_tree_mutex) || \ lockdep_is_held(&cgroup_mutex), \ - "cgroup_[tree_]mutex or RCU read lock required"); + "cgroup_mutex or RCU read lock required"); /* * cgroup destruction makes heavy use of work items and there can be a lot @@ -151,6 +149,13 @@ struct cgroup_root cgrp_dfl_root; */ static bool cgrp_dfl_root_visible; +/* some controllers are not supported in the default hierarchy */ +static const unsigned int cgrp_dfl_root_inhibit_ss_mask = 0 +#ifdef CONFIG_CGROUP_DEBUG + | (1 << debug_cgrp_id) +#endif + ; + /* The list of hierarchy roots */ static LIST_HEAD(cgroup_roots); @@ -160,14 +165,13 @@ static int cgroup_root_count; static DEFINE_IDR(cgroup_hierarchy_idr); /* - * Assign a monotonically increasing serial number to cgroups. It - * guarantees cgroups with bigger numbers are newer than those with smaller - * numbers. Also, as cgroups are always appended to the parent's - * ->children list, it guarantees that sibling cgroups are always sorted in - * the ascending serial number order on the list. Protected by - * cgroup_mutex. + * Assign a monotonically increasing serial number to csses. It guarantees + * cgroups with bigger numbers are newer than those with smaller numbers. + * Also, as csses are always appended to the parent's ->children list, it + * guarantees that sibling csses are always sorted in the ascending serial + * number order on the list. Protected by cgroup_mutex. */ -static u64 cgroup_serial_nr_next = 1; +static u64 css_serial_nr_next = 1; /* This flag indicates whether tasks in the fork and exit paths should * check for fork/exit handlers to call. This avoids us having to do @@ -180,17 +184,59 @@ static struct cftype cgroup_base_files[]; static void cgroup_put(struct cgroup *cgrp); static int rebind_subsystems(struct cgroup_root *dst_root, - unsigned long ss_mask); -static void cgroup_destroy_css_killed(struct cgroup *cgrp); + unsigned int ss_mask); static int cgroup_destroy_locked(struct cgroup *cgrp); +static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss); +static void css_release(struct percpu_ref *ref); +static void kill_css(struct cgroup_subsys_state *css); static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[], bool is_add); static void cgroup_pidlist_destroy_all(struct cgroup *cgrp); +/* IDR wrappers which synchronize using cgroup_idr_lock */ +static int cgroup_idr_alloc(struct idr *idr, void *ptr, int start, int end, + gfp_t gfp_mask) +{ + int ret; + + idr_preload(gfp_mask); + spin_lock_bh(&cgroup_idr_lock); + ret = idr_alloc(idr, ptr, start, end, gfp_mask); + spin_unlock_bh(&cgroup_idr_lock); + idr_preload_end(); + return ret; +} + +static void *cgroup_idr_replace(struct idr *idr, void *ptr, int id) +{ + void *ret; + + spin_lock_bh(&cgroup_idr_lock); + ret = idr_replace(idr, ptr, id); + spin_unlock_bh(&cgroup_idr_lock); + return ret; +} + +static void cgroup_idr_remove(struct idr *idr, int id) +{ + spin_lock_bh(&cgroup_idr_lock); + idr_remove(idr, id); + spin_unlock_bh(&cgroup_idr_lock); +} + +static struct cgroup *cgroup_parent(struct cgroup *cgrp) +{ + struct cgroup_subsys_state *parent_css = cgrp->self.parent; + + if (parent_css) + return container_of(parent_css, struct cgroup, self); + return NULL; +} + /** * cgroup_css - obtain a cgroup's css for the specified subsystem * @cgrp: the cgroup of interest - * @ss: the subsystem of interest (%NULL returns the dummy_css) + * @ss: the subsystem of interest (%NULL returns @cgrp->self) * * Return @cgrp's css (cgroup_subsys_state) associated with @ss. This * function must be called either under cgroup_mutex or rcu_read_lock() and @@ -203,23 +249,49 @@ static struct cgroup_subsys_state *cgroup_css(struct cgroup *cgrp, { if (ss) return rcu_dereference_check(cgrp->subsys[ss->id], - lockdep_is_held(&cgroup_tree_mutex) || lockdep_is_held(&cgroup_mutex)); else - return &cgrp->dummy_css; + return &cgrp->self; +} + +/** + * cgroup_e_css - obtain a cgroup's effective css for the specified subsystem + * @cgrp: the cgroup of interest + * @ss: the subsystem of interest (%NULL returns @cgrp->self) + * + * Similar to cgroup_css() but returns the effctive css, which is defined + * as the matching css of the nearest ancestor including self which has @ss + * enabled. If @ss is associated with the hierarchy @cgrp is on, this + * function is guaranteed to return non-NULL css. + */ +static struct cgroup_subsys_state *cgroup_e_css(struct cgroup *cgrp, + struct cgroup_subsys *ss) +{ + lockdep_assert_held(&cgroup_mutex); + + if (!ss) + return &cgrp->self; + + if (!(cgrp->root->subsys_mask & (1 << ss->id))) + return NULL; + + while (cgroup_parent(cgrp) && + !(cgroup_parent(cgrp)->child_subsys_mask & (1 << ss->id))) + cgrp = cgroup_parent(cgrp); + + return cgroup_css(cgrp, ss); } /* convenient tests for these bits */ static inline bool cgroup_is_dead(const struct cgroup *cgrp) { - return test_bit(CGRP_DEAD, &cgrp->flags); + return !(cgrp->self.flags & CSS_ONLINE); } -struct cgroup_subsys_state *seq_css(struct seq_file *seq) +struct cgroup_subsys_state *of_css(struct kernfs_open_file *of) { - struct kernfs_open_file *of = seq->private; struct cgroup *cgrp = of->kn->parent->priv; - struct cftype *cft = seq_cft(seq); + struct cftype *cft = of_cft(of); /* * This is open and unprotected implementation of cgroup_css(). @@ -232,9 +304,9 @@ struct cgroup_subsys_state *seq_css(struct seq_file *seq) if (cft->ss) return rcu_dereference_raw(cgrp->subsys[cft->ss->id]); else - return &cgrp->dummy_css; + return &cgrp->self; } -EXPORT_SYMBOL_GPL(seq_css); +EXPORT_SYMBOL_GPL(of_css); /** * cgroup_is_descendant - test ancestry @@ -250,7 +322,7 @@ bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor) while (cgrp) { if (cgrp == ancestor) return true; - cgrp = cgrp->parent; + cgrp = cgroup_parent(cgrp); } return false; } @@ -274,17 +346,30 @@ static int notify_on_release(const struct cgroup *cgrp) * @ssid: the index of the subsystem, CGROUP_SUBSYS_COUNT after reaching the end * @cgrp: the target cgroup to iterate css's of * - * Should be called under cgroup_mutex. + * Should be called under cgroup_[tree_]mutex. */ #define for_each_css(css, ssid, cgrp) \ for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++) \ if (!((css) = rcu_dereference_check( \ (cgrp)->subsys[(ssid)], \ - lockdep_is_held(&cgroup_tree_mutex) || \ lockdep_is_held(&cgroup_mutex)))) { } \ else /** + * for_each_e_css - iterate all effective css's of a cgroup + * @css: the iteration cursor + * @ssid: the index of the subsystem, CGROUP_SUBSYS_COUNT after reaching the end + * @cgrp: the target cgroup to iterate css's of + * + * Should be called under cgroup_[tree_]mutex. + */ +#define for_each_e_css(css, ssid, cgrp) \ + for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++) \ + if (!((css) = cgroup_e_css(cgrp, cgroup_subsys[(ssid)]))) \ + ; \ + else + +/** * for_each_subsys - iterate all enabled cgroup subsystems * @ss: the iteration cursor * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end @@ -297,22 +382,13 @@ static int notify_on_release(const struct cgroup *cgrp) #define for_each_root(root) \ list_for_each_entry((root), &cgroup_roots, root_list) -/** - * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive. - * @cgrp: the cgroup to be checked for liveness - * - * On success, returns true; the mutex should be later unlocked. On - * failure returns false with no lock held. - */ -static bool cgroup_lock_live_group(struct cgroup *cgrp) -{ - mutex_lock(&cgroup_mutex); - if (cgroup_is_dead(cgrp)) { - mutex_unlock(&cgroup_mutex); - return false; - } - return true; -} +/* iterate over child cgrps, lock should be held throughout iteration */ +#define cgroup_for_each_live_child(child, cgrp) \ + list_for_each_entry((child), &(cgrp)->self.children, self.sibling) \ + if (({ lockdep_assert_held(&cgroup_mutex); \ + cgroup_is_dead(child); })) \ + ; \ + else /* the list of cgroups eligible for automatic release. Protected by * release_list_lock */ @@ -360,6 +436,43 @@ struct css_set init_css_set = { static int css_set_count = 1; /* 1 for init_css_set */ +/** + * cgroup_update_populated - updated populated count of a cgroup + * @cgrp: the target cgroup + * @populated: inc or dec populated count + * + * @cgrp is either getting the first task (css_set) or losing the last. + * Update @cgrp->populated_cnt accordingly. The count is propagated + * towards root so that a given cgroup's populated_cnt is zero iff the + * cgroup and all its descendants are empty. + * + * @cgrp's interface file "cgroup.populated" is zero if + * @cgrp->populated_cnt is zero and 1 otherwise. When @cgrp->populated_cnt + * changes from or to zero, userland is notified that the content of the + * interface file has changed. This can be used to detect when @cgrp and + * its descendants become populated or empty. + */ +static void cgroup_update_populated(struct cgroup *cgrp, bool populated) +{ + lockdep_assert_held(&css_set_rwsem); + + do { + bool trigger; + + if (populated) + trigger = !cgrp->populated_cnt++; + else + trigger = !--cgrp->populated_cnt; + + if (!trigger) + break; + + if (cgrp->populated_kn) + kernfs_notify(cgrp->populated_kn); + cgrp = cgroup_parent(cgrp); + } while (cgrp); +} + /* * hash table for cgroup groups. This improves the performance to find * an existing css_set. This hash doesn't (currently) take into @@ -384,6 +497,8 @@ static unsigned long css_set_hash(struct cgroup_subsys_state *css[]) static void put_css_set_locked(struct css_set *cset, bool taskexit) { struct cgrp_cset_link *link, *tmp_link; + struct cgroup_subsys *ss; + int ssid; lockdep_assert_held(&css_set_rwsem); @@ -391,6 +506,8 @@ static void put_css_set_locked(struct css_set *cset, bool taskexit) return; /* This css_set is dead. unlink it and release cgroup refcounts */ + for_each_subsys(ss, ssid) + list_del(&cset->e_cset_node[ssid]); hash_del(&cset->hlist); css_set_count--; @@ -401,10 +518,13 @@ static void put_css_set_locked(struct css_set *cset, bool taskexit) list_del(&link->cgrp_link); /* @cgrp can't go away while we're holding css_set_rwsem */ - if (list_empty(&cgrp->cset_links) && notify_on_release(cgrp)) { - if (taskexit) - set_bit(CGRP_RELEASABLE, &cgrp->flags); - check_for_release(cgrp); + if (list_empty(&cgrp->cset_links)) { + cgroup_update_populated(cgrp, false); + if (notify_on_release(cgrp)) { + if (taskexit) + set_bit(CGRP_RELEASABLE, &cgrp->flags); + check_for_release(cgrp); + } } kfree(link); @@ -453,20 +573,20 @@ static bool compare_css_sets(struct css_set *cset, { struct list_head *l1, *l2; - if (memcmp(template, cset->subsys, sizeof(cset->subsys))) { - /* Not all subsystems matched */ + /* + * On the default hierarchy, there can be csets which are + * associated with the same set of cgroups but different csses. + * Let's first ensure that csses match. + */ + if (memcmp(template, cset->subsys, sizeof(cset->subsys))) return false; - } /* * Compare cgroup pointers in order to distinguish between - * different cgroups in heirarchies with no subsystems. We - * could get by with just this check alone (and skip the - * memcmp above) but on most setups the memcmp check will - * avoid the need for this more expensive check on almost all - * candidates. + * different cgroups in hierarchies. As different cgroups may + * share the same effective css, this comparison is always + * necessary. */ - l1 = &cset->cgrp_links; l2 = &old_cset->cgrp_links; while (1) { @@ -530,14 +650,17 @@ static struct css_set *find_existing_css_set(struct css_set *old_cset, * won't change, so no need for locking. */ for_each_subsys(ss, i) { - if (root->cgrp.subsys_mask & (1UL << i)) { - /* Subsystem is in this hierarchy. So we want - * the subsystem state from the new - * cgroup */ - template[i] = cgroup_css(cgrp, ss); + if (root->subsys_mask & (1UL << i)) { + /* + * @ss is in this hierarchy, so we want the + * effective css from @cgrp. + */ + template[i] = cgroup_e_css(cgrp, ss); } else { - /* Subsystem is not in this hierarchy, so we - * don't want to change the subsystem state */ + /* + * @ss is not in this hierarchy, so we don't want + * to change the css. + */ template[i] = old_cset->subsys[i]; } } @@ -603,10 +726,18 @@ static void link_css_set(struct list_head *tmp_links, struct css_set *cset, struct cgrp_cset_link *link; BUG_ON(list_empty(tmp_links)); + + if (cgroup_on_dfl(cgrp)) + cset->dfl_cgrp = cgrp; + link = list_first_entry(tmp_links, struct cgrp_cset_link, cset_link); link->cset = cset; link->cgrp = cgrp; + + if (list_empty(&cgrp->cset_links)) + cgroup_update_populated(cgrp, true); list_move(&link->cset_link, &cgrp->cset_links); + /* * Always add links to the tail of the list so that the list * is sorted by order of hierarchy creation @@ -629,7 +760,9 @@ static struct css_set *find_css_set(struct css_set *old_cset, struct css_set *cset; struct list_head tmp_links; struct cgrp_cset_link *link; + struct cgroup_subsys *ss; unsigned long key; + int ssid; lockdep_assert_held(&cgroup_mutex); @@ -680,10 +813,14 @@ static struct css_set *find_css_set(struct css_set *old_cset, css_set_count++; - /* Add this cgroup group to the hash table */ + /* Add @cset to the hash table */ key = css_set_hash(cset->subsys); hash_add(css_set_table, &cset->hlist, key); + for_each_subsys(ss, ssid) + list_add_tail(&cset->e_cset_node[ssid], + &cset->subsys[ssid]->cgroup->e_csets[ssid]); + up_write(&css_set_rwsem); return cset; @@ -736,14 +873,13 @@ static void cgroup_destroy_root(struct cgroup_root *root) struct cgroup *cgrp = &root->cgrp; struct cgrp_cset_link *link, *tmp_link; - mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); BUG_ON(atomic_read(&root->nr_cgrps)); - BUG_ON(!list_empty(&cgrp->children)); + BUG_ON(!list_empty(&cgrp->self.children)); /* Rebind all subsystems back to the default hierarchy */ - rebind_subsystems(&cgrp_dfl_root, cgrp->subsys_mask); + rebind_subsystems(&cgrp_dfl_root, root->subsys_mask); /* * Release all the links from cset_links to this hierarchy's @@ -766,7 +902,6 @@ static void cgroup_destroy_root(struct cgroup_root *root) cgroup_exit_root_id(root); mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); kernfs_destroy_root(root->kf_root); cgroup_free_root(root); @@ -849,7 +984,7 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task, * update of a tasks cgroup pointer by cgroup_attach_task() */ -static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask); +static int cgroup_populate_dir(struct cgroup *cgrp, unsigned int subsys_mask); static struct kernfs_syscall_ops cgroup_kf_syscall_ops; static const struct file_operations proc_cgroupstats_operations; @@ -884,79 +1019,95 @@ static umode_t cgroup_file_mode(const struct cftype *cft) if (cft->read_u64 || cft->read_s64 || cft->seq_show) mode |= S_IRUGO; - if (cft->write_u64 || cft->write_s64 || cft->write_string || - cft->trigger) + if (cft->write_u64 || cft->write_s64 || cft->write) mode |= S_IWUSR; return mode; } -static void cgroup_free_fn(struct work_struct *work) +static void cgroup_get(struct cgroup *cgrp) { - struct cgroup *cgrp = container_of(work, struct cgroup, destroy_work); - - atomic_dec(&cgrp->root->nr_cgrps); - cgroup_pidlist_destroy_all(cgrp); - - if (cgrp->parent) { - /* - * We get a ref to the parent, and put the ref when this - * cgroup is being freed, so it's guaranteed that the - * parent won't be destroyed before its children. - */ - cgroup_put(cgrp->parent); - kernfs_put(cgrp->kn); - kfree(cgrp); - } else { - /* - * This is root cgroup's refcnt reaching zero, which - * indicates that the root should be released. - */ - cgroup_destroy_root(cgrp->root); - } + WARN_ON_ONCE(cgroup_is_dead(cgrp)); + css_get(&cgrp->self); } -static void cgroup_free_rcu(struct rcu_head *head) +static void cgroup_put(struct cgroup *cgrp) { - struct cgroup *cgrp = container_of(head, struct cgroup, rcu_head); - - INIT_WORK(&cgrp->destroy_work, cgroup_free_fn); - queue_work(cgroup_destroy_wq, &cgrp->destroy_work); + css_put(&cgrp->self); } -static void cgroup_get(struct cgroup *cgrp) +/** + * cgroup_kn_unlock - unlocking helper for cgroup kernfs methods + * @kn: the kernfs_node being serviced + * + * This helper undoes cgroup_kn_lock_live() and should be invoked before + * the method finishes if locking succeeded. Note that once this function + * returns the cgroup returned by cgroup_kn_lock_live() may become + * inaccessible any time. If the caller intends to continue to access the + * cgroup, it should pin it before invoking this function. + */ +static void cgroup_kn_unlock(struct kernfs_node *kn) { - WARN_ON_ONCE(cgroup_is_dead(cgrp)); - WARN_ON_ONCE(atomic_read(&cgrp->refcnt) <= 0); - atomic_inc(&cgrp->refcnt); + struct cgroup *cgrp; + + if (kernfs_type(kn) == KERNFS_DIR) + cgrp = kn->priv; + else + cgrp = kn->parent->priv; + + mutex_unlock(&cgroup_mutex); + + kernfs_unbreak_active_protection(kn); + cgroup_put(cgrp); } -static void cgroup_put(struct cgroup *cgrp) +/** + * cgroup_kn_lock_live - locking helper for cgroup kernfs methods + * @kn: the kernfs_node being serviced + * + * This helper is to be used by a cgroup kernfs method currently servicing + * @kn. It breaks the active protection, performs cgroup locking and + * verifies that the associated cgroup is alive. Returns the cgroup if + * alive; otherwise, %NULL. A successful return should be undone by a + * matching cgroup_kn_unlock() invocation. + * + * Any cgroup kernfs method implementation which requires locking the + * associated cgroup should use this helper. It avoids nesting cgroup + * locking under kernfs active protection and allows all kernfs operations + * including self-removal. + */ +static struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn) { - if (!atomic_dec_and_test(&cgrp->refcnt)) - return; - if (WARN_ON_ONCE(cgrp->parent && !cgroup_is_dead(cgrp))) - return; + struct cgroup *cgrp; + + if (kernfs_type(kn) == KERNFS_DIR) + cgrp = kn->priv; + else + cgrp = kn->parent->priv; /* - * XXX: cgrp->id is only used to look up css's. As cgroup and - * css's lifetimes will be decoupled, it should be made - * per-subsystem and moved to css->id so that lookups are - * successful until the target css is released. + * We're gonna grab cgroup_mutex which nests outside kernfs + * active_ref. cgroup liveliness check alone provides enough + * protection against removal. Ensure @cgrp stays accessible and + * break the active_ref protection. */ + cgroup_get(cgrp); + kernfs_break_active_protection(kn); + mutex_lock(&cgroup_mutex); - idr_remove(&cgrp->root->cgroup_idr, cgrp->id); - mutex_unlock(&cgroup_mutex); - cgrp->id = -1; - call_rcu(&cgrp->rcu_head, cgroup_free_rcu); + if (!cgroup_is_dead(cgrp)) + return cgrp; + + cgroup_kn_unlock(kn); + return NULL; } static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) { char name[CGROUP_FILE_NAME_MAX]; - lockdep_assert_held(&cgroup_tree_mutex); + lockdep_assert_held(&cgroup_mutex); kernfs_remove_by_name(cgrp->kn, cgroup_file_name(cgrp, cft, name)); } @@ -965,7 +1116,7 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) * @cgrp: target cgroup * @subsys_mask: mask of the subsystem ids whose files should be removed */ -static void cgroup_clear_dir(struct cgroup *cgrp, unsigned long subsys_mask) +static void cgroup_clear_dir(struct cgroup *cgrp, unsigned int subsys_mask) { struct cgroup_subsys *ss; int i; @@ -973,40 +1124,40 @@ static void cgroup_clear_dir(struct cgroup *cgrp, unsigned long subsys_mask) for_each_subsys(ss, i) { struct cftype *cfts; - if (!test_bit(i, &subsys_mask)) + if (!(subsys_mask & (1 << i))) continue; list_for_each_entry(cfts, &ss->cfts, node) cgroup_addrm_files(cgrp, cfts, false); } } -static int rebind_subsystems(struct cgroup_root *dst_root, - unsigned long ss_mask) +static int rebind_subsystems(struct cgroup_root *dst_root, unsigned int ss_mask) { struct cgroup_subsys *ss; - int ssid, ret; + unsigned int tmp_ss_mask; + int ssid, i, ret; - lockdep_assert_held(&cgroup_tree_mutex); lockdep_assert_held(&cgroup_mutex); for_each_subsys(ss, ssid) { if (!(ss_mask & (1 << ssid))) continue; - /* if @ss is on the dummy_root, we can always move it */ - if (ss->root == &cgrp_dfl_root) - continue; - - /* if @ss has non-root cgroups attached to it, can't move */ - if (!list_empty(&ss->root->cgrp.children)) + /* if @ss has non-root csses attached to it, can't move */ + if (css_next_child(NULL, cgroup_css(&ss->root->cgrp, ss))) return -EBUSY; /* can't move between two non-dummy roots either */ - if (dst_root != &cgrp_dfl_root) + if (ss->root != &cgrp_dfl_root && dst_root != &cgrp_dfl_root) return -EBUSY; } - ret = cgroup_populate_dir(&dst_root->cgrp, ss_mask); + /* skip creating root files on dfl_root for inhibited subsystems */ + tmp_ss_mask = ss_mask; + if (dst_root == &cgrp_dfl_root) + tmp_ss_mask &= ~cgrp_dfl_root_inhibit_ss_mask; + + ret = cgroup_populate_dir(&dst_root->cgrp, tmp_ss_mask); if (ret) { if (dst_root != &cgrp_dfl_root) return ret; @@ -1018,9 +1169,9 @@ static int rebind_subsystems(struct cgroup_root *dst_root, * Just warn about it and continue. */ if (cgrp_dfl_root_visible) { - pr_warning("cgroup: failed to create files (%d) while rebinding 0x%lx to default root\n", - ret, ss_mask); - pr_warning("cgroup: you may retry by moving them to a different hierarchy and unbinding\n"); + pr_warn("failed to create files (%d) while rebinding 0x%x to default root\n", + ret, ss_mask); + pr_warn("you may retry by moving them to a different hierarchy and unbinding\n"); } } @@ -1028,15 +1179,14 @@ static int rebind_subsystems(struct cgroup_root *dst_root, * Nothing can fail from this point on. Remove files for the * removed subsystems and rebind each subsystem. */ - mutex_unlock(&cgroup_mutex); for_each_subsys(ss, ssid) if (ss_mask & (1 << ssid)) cgroup_clear_dir(&ss->root->cgrp, 1 << ssid); - mutex_lock(&cgroup_mutex); for_each_subsys(ss, ssid) { struct cgroup_root *src_root; struct cgroup_subsys_state *css; + struct css_set *cset; if (!(ss_mask & (1 << ssid))) continue; @@ -1051,8 +1201,19 @@ static int rebind_subsystems(struct cgroup_root *dst_root, ss->root = dst_root; css->cgroup = &dst_root->cgrp; - src_root->cgrp.subsys_mask &= ~(1 << ssid); - dst_root->cgrp.subsys_mask |= 1 << ssid; + down_write(&css_set_rwsem); + hash_for_each(css_set_table, i, cset, hlist) + list_move_tail(&cset->e_cset_node[ss->id], + &dst_root->cgrp.e_csets[ss->id]); + up_write(&css_set_rwsem); + + src_root->subsys_mask &= ~(1 << ssid); + src_root->cgrp.child_subsys_mask &= ~(1 << ssid); + + /* default hierarchy doesn't enable controllers by default */ + dst_root->subsys_mask |= 1 << ssid; + if (dst_root != &cgrp_dfl_root) + dst_root->cgrp.child_subsys_mask |= 1 << ssid; if (ss->bind) ss->bind(css); @@ -1070,7 +1231,7 @@ static int cgroup_show_options(struct seq_file *seq, int ssid; for_each_subsys(ss, ssid) - if (root->cgrp.subsys_mask & (1 << ssid)) + if (root->subsys_mask & (1 << ssid)) seq_printf(seq, ",%s", ss->name); if (root->flags & CGRP_ROOT_SANE_BEHAVIOR) seq_puts(seq, ",sane_behavior"); @@ -1092,8 +1253,8 @@ static int cgroup_show_options(struct seq_file *seq, } struct cgroup_sb_opts { - unsigned long subsys_mask; - unsigned long flags; + unsigned int subsys_mask; + unsigned int flags; char *release_agent; bool cpuset_clone_children; char *name; @@ -1101,24 +1262,16 @@ struct cgroup_sb_opts { bool none; }; -/* - * Convert a hierarchy specifier into a bitmask of subsystems and - * flags. Call with cgroup_mutex held to protect the cgroup_subsys[] - * array. This function takes refcounts on subsystems to be used, unless it - * returns error, in which case no refcounts are taken. - */ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) { char *token, *o = data; bool all_ss = false, one_ss = false; - unsigned long mask = (unsigned long)-1; + unsigned int mask = -1U; struct cgroup_subsys *ss; int i; - BUG_ON(!mutex_is_locked(&cgroup_mutex)); - #ifdef CONFIG_CPUSETS - mask = ~(1UL << cpuset_cgrp_id); + mask = ~(1U << cpuset_cgrp_id); #endif memset(opts, 0, sizeof(*opts)); @@ -1199,7 +1352,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) /* Mutually exclusive option 'all' + subsystem name */ if (all_ss) return -EINVAL; - set_bit(i, &opts->subsys_mask); + opts->subsys_mask |= (1 << i); one_ss = true; break; @@ -1211,12 +1364,12 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) /* Consistency checks */ if (opts->flags & CGRP_ROOT_SANE_BEHAVIOR) { - pr_warning("cgroup: sane_behavior: this is still under development and its behaviors will change, proceed at your own risk\n"); + pr_warn("sane_behavior: this is still under development and its behaviors will change, proceed at your own risk\n"); if ((opts->flags & (CGRP_ROOT_NOPREFIX | CGRP_ROOT_XATTR)) || opts->cpuset_clone_children || opts->release_agent || opts->name) { - pr_err("cgroup: sane_behavior: noprefix, xattr, clone_children, release_agent and name are not allowed\n"); + pr_err("sane_behavior: noprefix, xattr, clone_children, release_agent and name are not allowed\n"); return -EINVAL; } } else { @@ -1228,7 +1381,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) if (all_ss || (!one_ss && !opts->none && !opts->name)) for_each_subsys(ss, i) if (!ss->disabled) - set_bit(i, &opts->subsys_mask); + opts->subsys_mask |= (1 << i); /* * We either have to specify by name or by subsystems. (So @@ -1259,14 +1412,13 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data) int ret = 0; struct cgroup_root *root = cgroup_root_from_kf(kf_root); struct cgroup_sb_opts opts; - unsigned long added_mask, removed_mask; + unsigned int added_mask, removed_mask; if (root->flags & CGRP_ROOT_SANE_BEHAVIOR) { - pr_err("cgroup: sane_behavior: remount is not allowed\n"); + pr_err("sane_behavior: remount is not allowed\n"); return -EINVAL; } - mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); /* See what subsystems are wanted */ @@ -1274,17 +1426,17 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data) if (ret) goto out_unlock; - if (opts.subsys_mask != root->cgrp.subsys_mask || opts.release_agent) - pr_warning("cgroup: option changes via remount are deprecated (pid=%d comm=%s)\n", - task_tgid_nr(current), current->comm); + if (opts.subsys_mask != root->subsys_mask || opts.release_agent) + pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n", + task_tgid_nr(current), current->comm); - added_mask = opts.subsys_mask & ~root->cgrp.subsys_mask; - removed_mask = root->cgrp.subsys_mask & ~opts.subsys_mask; + added_mask = opts.subsys_mask & ~root->subsys_mask; + removed_mask = root->subsys_mask & ~opts.subsys_mask; /* Don't allow flags or name to change at remount */ if (((opts.flags ^ root->flags) & CGRP_ROOT_OPTION_MASK) || (opts.name && strcmp(opts.name, root->name))) { - pr_err("cgroup: option or name mismatch, new: 0x%lx \"%s\", old: 0x%lx \"%s\"\n", + pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n", opts.flags & CGRP_ROOT_OPTION_MASK, opts.name ?: "", root->flags & CGRP_ROOT_OPTION_MASK, root->name); ret = -EINVAL; @@ -1292,7 +1444,7 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data) } /* remounting is not allowed for populated hierarchies */ - if (!list_empty(&root->cgrp.children)) { + if (!list_empty(&root->cgrp.self.children)) { ret = -EBUSY; goto out_unlock; } @@ -1312,7 +1464,6 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data) kfree(opts.release_agent); kfree(opts.name); mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); return ret; } @@ -1370,14 +1521,22 @@ out_unlock: static void init_cgroup_housekeeping(struct cgroup *cgrp) { - atomic_set(&cgrp->refcnt, 1); - INIT_LIST_HEAD(&cgrp->sibling); - INIT_LIST_HEAD(&cgrp->children); + struct cgroup_subsys *ss; + int ssid; + + INIT_LIST_HEAD(&cgrp->self.sibling); + INIT_LIST_HEAD(&cgrp->self.children); INIT_LIST_HEAD(&cgrp->cset_links); INIT_LIST_HEAD(&cgrp->release_list); INIT_LIST_HEAD(&cgrp->pidlists); mutex_init(&cgrp->pidlist_mutex); - cgrp->dummy_css.cgroup = cgrp; + cgrp->self.cgroup = cgrp; + cgrp->self.flags |= CSS_ONLINE; + + for_each_subsys(ss, ssid) + INIT_LIST_HEAD(&cgrp->e_csets[ssid]); + + init_waitqueue_head(&cgrp->offline_waitq); } static void init_cgroup_root(struct cgroup_root *root, @@ -1400,21 +1559,24 @@ static void init_cgroup_root(struct cgroup_root *root, set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags); } -static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask) +static int cgroup_setup_root(struct cgroup_root *root, unsigned int ss_mask) { LIST_HEAD(tmp_links); struct cgroup *root_cgrp = &root->cgrp; struct css_set *cset; int i, ret; - lockdep_assert_held(&cgroup_tree_mutex); lockdep_assert_held(&cgroup_mutex); - ret = idr_alloc(&root->cgroup_idr, root_cgrp, 0, 1, GFP_KERNEL); + ret = cgroup_idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_NOWAIT); if (ret < 0) goto out; root_cgrp->id = ret; + ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release); + if (ret) + goto out; + /* * We're accessing css_set_count without locking css_set_rwsem here, * but that's OK - it can only be increased by someone holding @@ -1423,11 +1585,11 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask) */ ret = allocate_cgrp_cset_links(css_set_count, &tmp_links); if (ret) - goto out; + goto cancel_ref; ret = cgroup_init_root_id(root); if (ret) - goto out; + goto cancel_ref; root->kf_root = kernfs_create_root(&cgroup_kf_syscall_ops, KERNFS_ROOT_CREATE_DEACTIVATED, @@ -1463,7 +1625,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask) link_css_set(&tmp_links, cset, root_cgrp); up_write(&css_set_rwsem); - BUG_ON(!list_empty(&root_cgrp->children)); + BUG_ON(!list_empty(&root_cgrp->self.children)); BUG_ON(atomic_read(&root->nr_cgrps) != 1); kernfs_activate(root_cgrp->kn); @@ -1475,6 +1637,8 @@ destroy_root: root->kf_root = NULL; exit_root_id: cgroup_exit_root_id(root); +cancel_ref: + percpu_ref_cancel_init(&root_cgrp->self.refcnt); out: free_cgrp_cset_links(&tmp_links); return ret; @@ -1484,10 +1648,13 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, int flags, const char *unused_dev_name, void *data) { + struct super_block *pinned_sb = NULL; + struct cgroup_subsys *ss; struct cgroup_root *root; struct cgroup_sb_opts opts; struct dentry *dentry; int ret; + int i; bool new_sb; /* @@ -1497,14 +1664,13 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, if (!use_task_css_set_links) cgroup_enable_task_cg_lists(); - mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); /* First find the desired set of subsystems */ ret = parse_cgroupfs_options(data, &opts); if (ret) goto out_unlock; -retry: + /* look for a matching existing root */ if (!opts.subsys_mask && !opts.none && !opts.name) { cgrp_dfl_root_visible = true; @@ -1514,6 +1680,27 @@ retry: goto out_unlock; } + /* + * Destruction of cgroup root is asynchronous, so subsystems may + * still be dying after the previous unmount. Let's drain the + * dying subsystems. We just need to ensure that the ones + * unmounted previously finish dying and don't care about new ones + * starting. Testing ref liveliness is good enough. + */ + for_each_subsys(ss, i) { + if (!(opts.subsys_mask & (1 << i)) || + ss->root == &cgrp_dfl_root) + continue; + + if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) { + mutex_unlock(&cgroup_mutex); + msleep(10); + ret = restart_syscall(); + goto out_free; + } + cgroup_put(&ss->root->cgrp); + } + for_each_root(root) { bool name_match = false; @@ -1536,7 +1723,7 @@ retry: * subsystems) then they must match. */ if ((opts.subsys_mask || opts.none) && - (opts.subsys_mask != root->cgrp.subsys_mask)) { + (opts.subsys_mask != root->subsys_mask)) { if (!name_match) continue; ret = -EBUSY; @@ -1545,28 +1732,35 @@ retry: if ((root->flags ^ opts.flags) & CGRP_ROOT_OPTION_MASK) { if ((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) { - pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n"); + pr_err("sane_behavior: new mount options should match the existing superblock\n"); ret = -EINVAL; goto out_unlock; } else { - pr_warning("cgroup: new mount options do not match the existing superblock, will be ignored\n"); + pr_warn("new mount options do not match the existing superblock, will be ignored\n"); } } /* - * A root's lifetime is governed by its root cgroup. Zero - * ref indicate that the root is being destroyed. Wait for - * destruction to complete so that the subsystems are free. - * We can use wait_queue for the wait but this path is - * super cold. Let's just sleep for a bit and retry. + * We want to reuse @root whose lifetime is governed by its + * ->cgrp. Let's check whether @root is alive and keep it + * that way. As cgroup_kill_sb() can happen anytime, we + * want to block it by pinning the sb so that @root doesn't + * get killed before mount is complete. + * + * With the sb pinned, tryget_live can reliably indicate + * whether @root can be reused. If it's being killed, + * drain it. We can use wait_queue for the wait but this + * path is super cold. Let's just sleep a bit and retry. */ - if (!atomic_inc_not_zero(&root->cgrp.refcnt)) { + pinned_sb = kernfs_pin_sb(root->kf_root, NULL); + if (IS_ERR(pinned_sb) || + !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) { mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); + if (!IS_ERR_OR_NULL(pinned_sb)) + deactivate_super(pinned_sb); msleep(10); - mutex_lock(&cgroup_tree_mutex); - mutex_lock(&cgroup_mutex); - goto retry; + ret = restart_syscall(); + goto out_free; } ret = 0; @@ -1597,8 +1791,7 @@ retry: out_unlock: mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); - +out_free: kfree(opts.release_agent); kfree(opts.name); @@ -1609,6 +1802,16 @@ out_unlock: CGROUP_SUPER_MAGIC, &new_sb); if (IS_ERR(dentry) || !new_sb) cgroup_put(&root->cgrp); + + /* + * If @pinned_sb, we're reusing an existing root and holding an + * extra ref on its sb. Mount is complete. Put the extra ref. + */ + if (pinned_sb) { + WARN_ON(new_sb); + deactivate_super(pinned_sb); + } + return dentry; } @@ -1617,7 +1820,19 @@ static void cgroup_kill_sb(struct super_block *sb) struct kernfs_root *kf_root = kernfs_root_from_sb(sb); struct cgroup_root *root = cgroup_root_from_kf(kf_root); - cgroup_put(&root->cgrp); + /* + * If @root doesn't have any mounts or children, start killing it. + * This prevents new mounts by disabling percpu_ref_tryget_live(). + * cgroup_mount() may wait for @root's release. + * + * And don't kill the default root. + */ + if (css_has_online_children(&root->cgrp.self) || + root == &cgrp_dfl_root) + cgroup_put(&root->cgrp); + else + percpu_ref_kill(&root->cgrp.self.refcnt); + kernfs_kill_sb(sb); } @@ -1739,7 +1954,7 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset) /** * cgroup_task_migrate - move a task from one cgroup to another. - * @old_cgrp; the cgroup @tsk is being migrated from + * @old_cgrp: the cgroup @tsk is being migrated from * @tsk: the task being migrated * @new_cset: the new css_set @tsk is being attached to * @@ -1831,10 +2046,6 @@ static void cgroup_migrate_add_src(struct css_set *src_cset, src_cgrp = cset_cgroup_from_root(src_cset, dst_cgrp->root); - /* nothing to do if this cset already belongs to the cgroup */ - if (src_cgrp == dst_cgrp) - return; - if (!list_empty(&src_cset->mg_preload_node)) return; @@ -1849,13 +2060,14 @@ static void cgroup_migrate_add_src(struct css_set *src_cset, /** * cgroup_migrate_prepare_dst - prepare destination css_sets for migration - * @dst_cgrp: the destination cgroup + * @dst_cgrp: the destination cgroup (may be %NULL) * @preloaded_csets: list of preloaded source css_sets * * Tasks are about to be moved to @dst_cgrp and all the source css_sets * have been preloaded to @preloaded_csets. This function looks up and - * pins all destination css_sets, links each to its source, and put them on - * @preloaded_csets. + * pins all destination css_sets, links each to its source, and append them + * to @preloaded_csets. If @dst_cgrp is %NULL, the destination of each + * source css_set is assumed to be its cgroup on the default hierarchy. * * This function must be called after cgroup_migrate_add_src() has been * called on each migration source css_set. After migration is performed @@ -1866,19 +2078,42 @@ static int cgroup_migrate_prepare_dst(struct cgroup *dst_cgrp, struct list_head *preloaded_csets) { LIST_HEAD(csets); - struct css_set *src_cset; + struct css_set *src_cset, *tmp_cset; lockdep_assert_held(&cgroup_mutex); + /* + * Except for the root, child_subsys_mask must be zero for a cgroup + * with tasks so that child cgroups don't compete against tasks. + */ + if (dst_cgrp && cgroup_on_dfl(dst_cgrp) && cgroup_parent(dst_cgrp) && + dst_cgrp->child_subsys_mask) + return -EBUSY; + /* look up the dst cset for each src cset and link it to src */ - list_for_each_entry(src_cset, preloaded_csets, mg_preload_node) { + list_for_each_entry_safe(src_cset, tmp_cset, preloaded_csets, mg_preload_node) { struct css_set *dst_cset; - dst_cset = find_css_set(src_cset, dst_cgrp); + dst_cset = find_css_set(src_cset, + dst_cgrp ?: src_cset->dfl_cgrp); if (!dst_cset) goto err; WARN_ON_ONCE(src_cset->mg_dst_cset || dst_cset->mg_dst_cset); + + /* + * If src cset equals dst, it's noop. Drop the src. + * cgroup_migrate() will skip the cset too. Note that we + * can't handle src == dst as some nodes are used by both. + */ + if (src_cset == dst_cset) { + src_cset->mg_src_cgrp = NULL; + list_del_init(&src_cset->mg_preload_node); + put_css_set(src_cset, false); + put_css_set(dst_cset, false); + continue; + } + src_cset->mg_dst_cset = dst_cset; if (list_empty(&dst_cset->mg_preload_node)) @@ -1887,7 +2122,7 @@ static int cgroup_migrate_prepare_dst(struct cgroup *dst_cgrp, put_css_set(dst_cset, false); } - list_splice(&csets, preloaded_csets); + list_splice_tail(&csets, preloaded_csets); return 0; err: cgroup_migrate_finish(&csets); @@ -1968,7 +2203,7 @@ static int cgroup_migrate(struct cgroup *cgrp, struct task_struct *leader, return 0; /* check that we can legitimately attach to the cgroup */ - for_each_css(css, i, cgrp) { + for_each_e_css(css, i, cgrp) { if (css->ss->can_attach) { ret = css->ss->can_attach(css, &tset); if (ret) { @@ -1998,7 +2233,7 @@ static int cgroup_migrate(struct cgroup *cgrp, struct task_struct *leader, */ tset.csets = &tset.dst_csets; - for_each_css(css, i, cgrp) + for_each_e_css(css, i, cgrp) if (css->ss->attach) css->ss->attach(css, &tset); @@ -2006,7 +2241,7 @@ static int cgroup_migrate(struct cgroup *cgrp, struct task_struct *leader, goto out_release_tset; out_cancel_attach: - for_each_css(css, i, cgrp) { + for_each_e_css(css, i, cgrp) { if (css == failed_css) break; if (css->ss->cancel_attach) @@ -2065,13 +2300,20 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp, * function to attach either it or all tasks in its threadgroup. Will lock * cgroup_mutex and threadgroup. */ -static int attach_task_by_pid(struct cgroup *cgrp, u64 pid, bool threadgroup) +static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off, bool threadgroup) { struct task_struct *tsk; const struct cred *cred = current_cred(), *tcred; + struct cgroup *cgrp; + pid_t pid; int ret; - if (!cgroup_lock_live_group(cgrp)) + if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0) + return -EINVAL; + + cgrp = cgroup_kn_lock_live(of->kn); + if (!cgrp) return -ENODEV; retry_find_task: @@ -2137,8 +2379,8 @@ retry_find_task: put_task_struct(tsk); out_unlock_cgroup: - mutex_unlock(&cgroup_mutex); - return ret; + cgroup_kn_unlock(of->kn); + return ret ?: nbytes; } /** @@ -2172,43 +2414,44 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) } EXPORT_SYMBOL_GPL(cgroup_attach_task_all); -static int cgroup_tasks_write(struct cgroup_subsys_state *css, - struct cftype *cft, u64 pid) +static ssize_t cgroup_tasks_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) { - return attach_task_by_pid(css->cgroup, pid, false); + return __cgroup_procs_write(of, buf, nbytes, off, false); } -static int cgroup_procs_write(struct cgroup_subsys_state *css, - struct cftype *cft, u64 tgid) +static ssize_t cgroup_procs_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) { - return attach_task_by_pid(css->cgroup, tgid, true); + return __cgroup_procs_write(of, buf, nbytes, off, true); } -static int cgroup_release_agent_write(struct cgroup_subsys_state *css, - struct cftype *cft, char *buffer) +static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) { - struct cgroup_root *root = css->cgroup->root; + struct cgroup *cgrp; + + BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX); - BUILD_BUG_ON(sizeof(root->release_agent_path) < PATH_MAX); - if (!cgroup_lock_live_group(css->cgroup)) + cgrp = cgroup_kn_lock_live(of->kn); + if (!cgrp) return -ENODEV; spin_lock(&release_agent_path_lock); - strlcpy(root->release_agent_path, buffer, - sizeof(root->release_agent_path)); + strlcpy(cgrp->root->release_agent_path, strstrip(buf), + sizeof(cgrp->root->release_agent_path)); spin_unlock(&release_agent_path_lock); - mutex_unlock(&cgroup_mutex); - return 0; + cgroup_kn_unlock(of->kn); + return nbytes; } static int cgroup_release_agent_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - if (!cgroup_lock_live_group(cgrp)) - return -ENODEV; + spin_lock(&release_agent_path_lock); seq_puts(seq, cgrp->root->release_agent_path); + spin_unlock(&release_agent_path_lock); seq_putc(seq, '\n'); - mutex_unlock(&cgroup_mutex); return 0; } @@ -2220,6 +2463,320 @@ static int cgroup_sane_behavior_show(struct seq_file *seq, void *v) return 0; } +static void cgroup_print_ss_mask(struct seq_file *seq, unsigned int ss_mask) +{ + struct cgroup_subsys *ss; + bool printed = false; + int ssid; + + for_each_subsys(ss, ssid) { + if (ss_mask & (1 << ssid)) { + if (printed) + seq_putc(seq, ' '); + seq_printf(seq, "%s", ss->name); + printed = true; + } + } + if (printed) + seq_putc(seq, '\n'); +} + +/* show controllers which are currently attached to the default hierarchy */ +static int cgroup_root_controllers_show(struct seq_file *seq, void *v) +{ + struct cgroup *cgrp = seq_css(seq)->cgroup; + + cgroup_print_ss_mask(seq, cgrp->root->subsys_mask & + ~cgrp_dfl_root_inhibit_ss_mask); + return 0; +} + +/* show controllers which are enabled from the parent */ +static int cgroup_controllers_show(struct seq_file *seq, void *v) +{ + struct cgroup *cgrp = seq_css(seq)->cgroup; + + cgroup_print_ss_mask(seq, cgroup_parent(cgrp)->child_subsys_mask); + return 0; +} + +/* show controllers which are enabled for a given cgroup's children */ +static int cgroup_subtree_control_show(struct seq_file *seq, void *v) +{ + struct cgroup *cgrp = seq_css(seq)->cgroup; + + cgroup_print_ss_mask(seq, cgrp->child_subsys_mask); + return 0; +} + +/** + * cgroup_update_dfl_csses - update css assoc of a subtree in default hierarchy + * @cgrp: root of the subtree to update csses for + * + * @cgrp's child_subsys_mask has changed and its subtree's (self excluded) + * css associations need to be updated accordingly. This function looks up + * all css_sets which are attached to the subtree, creates the matching + * updated css_sets and migrates the tasks to the new ones. + */ +static int cgroup_update_dfl_csses(struct cgroup *cgrp) +{ + LIST_HEAD(preloaded_csets); + struct cgroup_subsys_state *css; + struct css_set *src_cset; + int ret; + + lockdep_assert_held(&cgroup_mutex); + + /* look up all csses currently attached to @cgrp's subtree */ + down_read(&css_set_rwsem); + css_for_each_descendant_pre(css, cgroup_css(cgrp, NULL)) { + struct cgrp_cset_link *link; + + /* self is not affected by child_subsys_mask change */ + if (css->cgroup == cgrp) + continue; + + list_for_each_entry(link, &css->cgroup->cset_links, cset_link) + cgroup_migrate_add_src(link->cset, cgrp, + &preloaded_csets); + } + up_read(&css_set_rwsem); + + /* NULL dst indicates self on default hierarchy */ + ret = cgroup_migrate_prepare_dst(NULL, &preloaded_csets); + if (ret) + goto out_finish; + + list_for_each_entry(src_cset, &preloaded_csets, mg_preload_node) { + struct task_struct *last_task = NULL, *task; + + /* src_csets precede dst_csets, break on the first dst_cset */ + if (!src_cset->mg_src_cgrp) + break; + + /* + * All tasks in src_cset need to be migrated to the + * matching dst_cset. Empty it process by process. We + * walk tasks but migrate processes. The leader might even + * belong to a different cset but such src_cset would also + * be among the target src_csets because the default + * hierarchy enforces per-process membership. + */ + while (true) { + down_read(&css_set_rwsem); + task = list_first_entry_or_null(&src_cset->tasks, + struct task_struct, cg_list); + if (task) { + task = task->group_leader; + WARN_ON_ONCE(!task_css_set(task)->mg_src_cgrp); + get_task_struct(task); + } + up_read(&css_set_rwsem); + + if (!task) + break; + + /* guard against possible infinite loop */ + if (WARN(last_task == task, + "cgroup: update_dfl_csses failed to make progress, aborting in inconsistent state\n")) + goto out_finish; + last_task = task; + + threadgroup_lock(task); + /* raced against de_thread() from another thread? */ + if (!thread_group_leader(task)) { + threadgroup_unlock(task); + put_task_struct(task); + continue; + } + + ret = cgroup_migrate(src_cset->dfl_cgrp, task, true); + + threadgroup_unlock(task); + put_task_struct(task); + + if (WARN(ret, "cgroup: failed to update controllers for the default hierarchy (%d), further operations may crash or hang\n", ret)) + goto out_finish; + } + } + +out_finish: + cgroup_migrate_finish(&preloaded_csets); + return ret; +} + +/* change the enabled child controllers for a cgroup in the default hierarchy */ +static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, + loff_t off) +{ + unsigned int enable = 0, disable = 0; + struct cgroup *cgrp, *child; + struct cgroup_subsys *ss; + char *tok; + int ssid, ret; + + /* + * Parse input - space separated list of subsystem names prefixed + * with either + or -. + */ + buf = strstrip(buf); + while ((tok = strsep(&buf, " "))) { + if (tok[0] == '\0') + continue; + for_each_subsys(ss, ssid) { + if (ss->disabled || strcmp(tok + 1, ss->name) || + ((1 << ss->id) & cgrp_dfl_root_inhibit_ss_mask)) + continue; + + if (*tok == '+') { + enable |= 1 << ssid; + disable &= ~(1 << ssid); + } else if (*tok == '-') { + disable |= 1 << ssid; + enable &= ~(1 << ssid); + } else { + return -EINVAL; + } + break; + } + if (ssid == CGROUP_SUBSYS_COUNT) + return -EINVAL; + } + + cgrp = cgroup_kn_lock_live(of->kn); + if (!cgrp) + return -ENODEV; + + for_each_subsys(ss, ssid) { + if (enable & (1 << ssid)) { + if (cgrp->child_subsys_mask & (1 << ssid)) { + enable &= ~(1 << ssid); + continue; + } + + /* + * Because css offlining is asynchronous, userland + * might try to re-enable the same controller while + * the previous instance is still around. In such + * cases, wait till it's gone using offline_waitq. + */ + cgroup_for_each_live_child(child, cgrp) { + DEFINE_WAIT(wait); + + if (!cgroup_css(child, ss)) + continue; + + cgroup_get(child); + prepare_to_wait(&child->offline_waitq, &wait, + TASK_UNINTERRUPTIBLE); + cgroup_kn_unlock(of->kn); + schedule(); + finish_wait(&child->offline_waitq, &wait); + cgroup_put(child); + + return restart_syscall(); + } + + /* unavailable or not enabled on the parent? */ + if (!(cgrp_dfl_root.subsys_mask & (1 << ssid)) || + (cgroup_parent(cgrp) && + !(cgroup_parent(cgrp)->child_subsys_mask & (1 << ssid)))) { + ret = -ENOENT; + goto out_unlock; + } + } else if (disable & (1 << ssid)) { + if (!(cgrp->child_subsys_mask & (1 << ssid))) { + disable &= ~(1 << ssid); + continue; + } + + /* a child has it enabled? */ + cgroup_for_each_live_child(child, cgrp) { + if (child->child_subsys_mask & (1 << ssid)) { + ret = -EBUSY; + goto out_unlock; + } + } + } + } + + if (!enable && !disable) { + ret = 0; + goto out_unlock; + } + + /* + * Except for the root, child_subsys_mask must be zero for a cgroup + * with tasks so that child cgroups don't compete against tasks. + */ + if (enable && cgroup_parent(cgrp) && !list_empty(&cgrp->cset_links)) { + ret = -EBUSY; + goto out_unlock; + } + + /* + * Create csses for enables and update child_subsys_mask. This + * changes cgroup_e_css() results which in turn makes the + * subsequent cgroup_update_dfl_csses() associate all tasks in the + * subtree to the updated csses. + */ + for_each_subsys(ss, ssid) { + if (!(enable & (1 << ssid))) + continue; + + cgroup_for_each_live_child(child, cgrp) { + ret = create_css(child, ss); + if (ret) + goto err_undo_css; + } + } + + cgrp->child_subsys_mask |= enable; + cgrp->child_subsys_mask &= ~disable; + + ret = cgroup_update_dfl_csses(cgrp); + if (ret) + goto err_undo_css; + + /* all tasks are now migrated away from the old csses, kill them */ + for_each_subsys(ss, ssid) { + if (!(disable & (1 << ssid))) + continue; + + cgroup_for_each_live_child(child, cgrp) + kill_css(cgroup_css(child, ss)); + } + + kernfs_activate(cgrp->kn); + ret = 0; +out_unlock: + cgroup_kn_unlock(of->kn); + return ret ?: nbytes; + +err_undo_css: + cgrp->child_subsys_mask &= ~enable; + cgrp->child_subsys_mask |= disable; + + for_each_subsys(ss, ssid) { + if (!(enable & (1 << ssid))) + continue; + + cgroup_for_each_live_child(child, cgrp) { + struct cgroup_subsys_state *css = cgroup_css(child, ss); + if (css) + kill_css(css); + } + } + goto out_unlock; +} + +static int cgroup_populated_show(struct seq_file *seq, void *v) +{ + seq_printf(seq, "%d\n", (bool)seq_css(seq)->cgroup->populated_cnt); + return 0; +} + static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { @@ -2228,6 +2785,9 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, struct cgroup_subsys_state *css; int ret; + if (cft->write) + return cft->write(of, buf, nbytes, off); + /* * kernfs guarantees that a file isn't deleted with operations in * flight, which means that the matching css is and stays alive and @@ -2238,9 +2798,7 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, css = cgroup_css(cgrp, cft->ss); rcu_read_unlock(); - if (cft->write_string) { - ret = cft->write_string(css, cft, strstrip(buf)); - } else if (cft->write_u64) { + if (cft->write_u64) { unsigned long long v; ret = kstrtoull(buf, 0, &v); if (!ret) @@ -2250,8 +2808,6 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, ret = kstrtoll(buf, 0, &v); if (!ret) ret = cft->write_s64(css, cft, v); - } else if (cft->trigger) { - ret = cft->trigger(css, (unsigned int)cft->private); } else { ret = -EINVAL; } @@ -2328,20 +2884,18 @@ static int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent, return -EPERM; /* - * We're gonna grab cgroup_tree_mutex which nests outside kernfs + * We're gonna grab cgroup_mutex which nests outside kernfs * active_ref. kernfs_rename() doesn't require active_ref - * protection. Break them before grabbing cgroup_tree_mutex. + * protection. Break them before grabbing cgroup_mutex. */ kernfs_break_active_protection(new_parent); kernfs_break_active_protection(kn); - mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); ret = kernfs_rename(kn, new_parent, new_name_str); mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); kernfs_unbreak_active_protection(kn); kernfs_unbreak_active_protection(new_parent); @@ -2379,9 +2933,14 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft) return PTR_ERR(kn); ret = cgroup_kn_set_ugid(kn); - if (ret) + if (ret) { kernfs_remove(kn); - return ret; + return ret; + } + + if (cft->seq_show == cgroup_populated_show) + cgrp->populated_kn = kn; + return 0; } /** @@ -2401,7 +2960,7 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[], struct cftype *cft; int ret; - lockdep_assert_held(&cgroup_tree_mutex); + lockdep_assert_held(&cgroup_mutex); for (cft = cfts; cft->name[0] != '\0'; cft++) { /* does cft->flags tell us to skip this file on @cgrp? */ @@ -2409,16 +2968,16 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[], continue; if ((cft->flags & CFTYPE_INSANE) && cgroup_sane_behavior(cgrp)) continue; - if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgrp->parent) + if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgroup_parent(cgrp)) continue; - if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent) + if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgroup_parent(cgrp)) continue; if (is_add) { ret = cgroup_add_file(cgrp, cft); if (ret) { - pr_warn("cgroup_addrm_files: failed to add %s, err=%d\n", - cft->name, ret); + pr_warn("%s: failed to add %s, err=%d\n", + __func__, cft->name, ret); return ret; } } else { @@ -2436,11 +2995,7 @@ static int cgroup_apply_cftypes(struct cftype *cfts, bool is_add) struct cgroup_subsys_state *css; int ret = 0; - lockdep_assert_held(&cgroup_tree_mutex); - - /* don't bother if @ss isn't attached */ - if (ss->root == &cgrp_dfl_root) - return 0; + lockdep_assert_held(&cgroup_mutex); /* add/rm files for all cgroups created before */ css_for_each_descendant_pre(css, cgroup_css(root, ss)) { @@ -2508,7 +3063,7 @@ static int cgroup_init_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) static int cgroup_rm_cftypes_locked(struct cftype *cfts) { - lockdep_assert_held(&cgroup_tree_mutex); + lockdep_assert_held(&cgroup_mutex); if (!cfts || !cfts[0].ss) return -ENOENT; @@ -2534,9 +3089,9 @@ int cgroup_rm_cftypes(struct cftype *cfts) { int ret; - mutex_lock(&cgroup_tree_mutex); + mutex_lock(&cgroup_mutex); ret = cgroup_rm_cftypes_locked(cfts); - mutex_unlock(&cgroup_tree_mutex); + mutex_unlock(&cgroup_mutex); return ret; } @@ -2558,6 +3113,9 @@ int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) { int ret; + if (ss->disabled) + return 0; + if (!cfts || cfts[0].name[0] == '\0') return 0; @@ -2565,14 +3123,14 @@ int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) if (ret) return ret; - mutex_lock(&cgroup_tree_mutex); + mutex_lock(&cgroup_mutex); list_add_tail(&cfts->node, &ss->cfts); ret = cgroup_apply_cftypes(cfts, true); if (ret) cgroup_rm_cftypes_locked(cfts); - mutex_unlock(&cgroup_tree_mutex); + mutex_unlock(&cgroup_mutex); return ret; } @@ -2596,57 +3154,65 @@ static int cgroup_task_count(const struct cgroup *cgrp) /** * css_next_child - find the next child of a given css - * @pos_css: the current position (%NULL to initiate traversal) - * @parent_css: css whose children to walk + * @pos: the current position (%NULL to initiate traversal) + * @parent: css whose children to walk * - * This function returns the next child of @parent_css and should be called + * This function returns the next child of @parent and should be called * under either cgroup_mutex or RCU read lock. The only requirement is - * that @parent_css and @pos_css are accessible. The next sibling is - * guaranteed to be returned regardless of their states. + * that @parent and @pos are accessible. The next sibling is guaranteed to + * be returned regardless of their states. + * + * If a subsystem synchronizes ->css_online() and the start of iteration, a + * css which finished ->css_online() is guaranteed to be visible in the + * future iterations and will stay visible until the last reference is put. + * A css which hasn't finished ->css_online() or already finished + * ->css_offline() may show up during traversal. It's each subsystem's + * responsibility to synchronize against on/offlining. */ -struct cgroup_subsys_state * -css_next_child(struct cgroup_subsys_state *pos_css, - struct cgroup_subsys_state *parent_css) +struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, + struct cgroup_subsys_state *parent) { - struct cgroup *pos = pos_css ? pos_css->cgroup : NULL; - struct cgroup *cgrp = parent_css->cgroup; - struct cgroup *next; + struct cgroup_subsys_state *next; - cgroup_assert_mutexes_or_rcu_locked(); + cgroup_assert_mutex_or_rcu_locked(); /* - * @pos could already have been removed. Once a cgroup is removed, - * its ->sibling.next is no longer updated when its next sibling - * changes. As CGRP_DEAD assertion is serialized and happens - * before the cgroup is taken off the ->sibling list, if we see it - * unasserted, it's guaranteed that the next sibling hasn't - * finished its grace period even if it's already removed, and thus - * safe to dereference from this RCU critical section. If - * ->sibling.next is inaccessible, cgroup_is_dead() is guaranteed - * to be visible as %true here. + * @pos could already have been unlinked from the sibling list. + * Once a cgroup is removed, its ->sibling.next is no longer + * updated when its next sibling changes. CSS_RELEASED is set when + * @pos is taken off list, at which time its next pointer is valid, + * and, as releases are serialized, the one pointed to by the next + * pointer is guaranteed to not have started release yet. This + * implies that if we observe !CSS_RELEASED on @pos in this RCU + * critical section, the one pointed to by its next pointer is + * guaranteed to not have finished its RCU grace period even if we + * have dropped rcu_read_lock() inbetween iterations. * - * If @pos is dead, its next pointer can't be dereferenced; - * however, as each cgroup is given a monotonically increasing - * unique serial number and always appended to the sibling list, - * the next one can be found by walking the parent's children until - * we see a cgroup with higher serial number than @pos's. While - * this path can be slower, it's taken only when either the current - * cgroup is removed or iteration and removal race. + * If @pos has CSS_RELEASED set, its next pointer can't be + * dereferenced; however, as each css is given a monotonically + * increasing unique serial number and always appended to the + * sibling list, the next one can be found by walking the parent's + * children until the first css with higher serial number than + * @pos's. While this path can be slower, it happens iff iteration + * races against release and the race window is very small. */ if (!pos) { - next = list_entry_rcu(cgrp->children.next, struct cgroup, sibling); - } else if (likely(!cgroup_is_dead(pos))) { - next = list_entry_rcu(pos->sibling.next, struct cgroup, sibling); + next = list_entry_rcu(parent->children.next, struct cgroup_subsys_state, sibling); + } else if (likely(!(pos->flags & CSS_RELEASED))) { + next = list_entry_rcu(pos->sibling.next, struct cgroup_subsys_state, sibling); } else { - list_for_each_entry_rcu(next, &cgrp->children, sibling) + list_for_each_entry_rcu(next, &parent->children, sibling) if (next->serial_nr > pos->serial_nr) break; } - if (&next->sibling == &cgrp->children) - return NULL; - - return cgroup_css(next, parent_css->ss); + /* + * @next, if not pointing to the head, can be dereferenced and is + * the next sibling. + */ + if (&next->sibling != &parent->children) + return next; + return NULL; } /** @@ -2662,6 +3228,13 @@ css_next_child(struct cgroup_subsys_state *pos_css, * doesn't require the whole traversal to be contained in a single critical * section. This function will return the correct next descendant as long * as both @pos and @root are accessible and @pos is a descendant of @root. + * + * If a subsystem synchronizes ->css_online() and the start of iteration, a + * css which finished ->css_online() is guaranteed to be visible in the + * future iterations and will stay visible until the last reference is put. + * A css which hasn't finished ->css_online() or already finished + * ->css_offline() may show up during traversal. It's each subsystem's + * responsibility to synchronize against on/offlining. */ struct cgroup_subsys_state * css_next_descendant_pre(struct cgroup_subsys_state *pos, @@ -2669,7 +3242,7 @@ css_next_descendant_pre(struct cgroup_subsys_state *pos, { struct cgroup_subsys_state *next; - cgroup_assert_mutexes_or_rcu_locked(); + cgroup_assert_mutex_or_rcu_locked(); /* if first iteration, visit @root */ if (!pos) @@ -2682,10 +3255,10 @@ css_next_descendant_pre(struct cgroup_subsys_state *pos, /* no child, visit my or the closest ancestor's next sibling */ while (pos != root) { - next = css_next_child(pos, css_parent(pos)); + next = css_next_child(pos, pos->parent); if (next) return next; - pos = css_parent(pos); + pos = pos->parent; } return NULL; @@ -2709,7 +3282,7 @@ css_rightmost_descendant(struct cgroup_subsys_state *pos) { struct cgroup_subsys_state *last, *tmp; - cgroup_assert_mutexes_or_rcu_locked(); + cgroup_assert_mutex_or_rcu_locked(); do { last = pos; @@ -2749,6 +3322,13 @@ css_leftmost_descendant(struct cgroup_subsys_state *pos) * section. This function will return the correct next descendant as long * as both @pos and @cgroup are accessible and @pos is a descendant of * @cgroup. + * + * If a subsystem synchronizes ->css_online() and the start of iteration, a + * css which finished ->css_online() is guaranteed to be visible in the + * future iterations and will stay visible until the last reference is put. + * A css which hasn't finished ->css_online() or already finished + * ->css_offline() may show up during traversal. It's each subsystem's + * responsibility to synchronize against on/offlining. */ struct cgroup_subsys_state * css_next_descendant_post(struct cgroup_subsys_state *pos, @@ -2756,7 +3336,7 @@ css_next_descendant_post(struct cgroup_subsys_state *pos, { struct cgroup_subsys_state *next; - cgroup_assert_mutexes_or_rcu_locked(); + cgroup_assert_mutex_or_rcu_locked(); /* if first iteration, visit leftmost descendant which may be @root */ if (!pos) @@ -2767,12 +3347,36 @@ css_next_descendant_post(struct cgroup_subsys_state *pos, return NULL; /* if there's an unvisited sibling, visit its leftmost descendant */ - next = css_next_child(pos, css_parent(pos)); + next = css_next_child(pos, pos->parent); if (next) return css_leftmost_descendant(next); /* no sibling left, visit parent */ - return css_parent(pos); + return pos->parent; +} + +/** + * css_has_online_children - does a css have online children + * @css: the target css + * + * Returns %true if @css has any online children; otherwise, %false. This + * function can be called from any context but the caller is responsible + * for synchronizing against on/offlining as necessary. + */ +bool css_has_online_children(struct cgroup_subsys_state *css) +{ + struct cgroup_subsys_state *child; + bool ret = false; + + rcu_read_lock(); + css_for_each_child(child, css) { + if (child->flags & CSS_ONLINE) { + ret = true; + break; + } + } + rcu_read_unlock(); + return ret; } /** @@ -2783,27 +3387,36 @@ css_next_descendant_post(struct cgroup_subsys_state *pos, */ static void css_advance_task_iter(struct css_task_iter *it) { - struct list_head *l = it->cset_link; + struct list_head *l = it->cset_pos; struct cgrp_cset_link *link; struct css_set *cset; /* Advance to the next non-empty css_set */ do { l = l->next; - if (l == &it->origin_css->cgroup->cset_links) { - it->cset_link = NULL; + if (l == it->cset_head) { + it->cset_pos = NULL; return; } - link = list_entry(l, struct cgrp_cset_link, cset_link); - cset = link->cset; + + if (it->ss) { + cset = container_of(l, struct css_set, + e_cset_node[it->ss->id]); + } else { + link = list_entry(l, struct cgrp_cset_link, cset_link); + cset = link->cset; + } } while (list_empty(&cset->tasks) && list_empty(&cset->mg_tasks)); - it->cset_link = l; + it->cset_pos = l; if (!list_empty(&cset->tasks)) - it->task = cset->tasks.next; + it->task_pos = cset->tasks.next; else - it->task = cset->mg_tasks.next; + it->task_pos = cset->mg_tasks.next; + + it->tasks_head = &cset->tasks; + it->mg_tasks_head = &cset->mg_tasks; } /** @@ -2829,8 +3442,14 @@ void css_task_iter_start(struct cgroup_subsys_state *css, down_read(&css_set_rwsem); - it->origin_css = css; - it->cset_link = &css->cgroup->cset_links; + it->ss = css->ss; + + if (it->ss) + it->cset_pos = &css->cgroup->e_csets[css->ss->id]; + else + it->cset_pos = &css->cgroup->cset_links; + + it->cset_head = it->cset_pos; css_advance_task_iter(it); } @@ -2846,12 +3465,10 @@ void css_task_iter_start(struct cgroup_subsys_state *css, struct task_struct *css_task_iter_next(struct css_task_iter *it) { struct task_struct *res; - struct list_head *l = it->task; - struct cgrp_cset_link *link = list_entry(it->cset_link, - struct cgrp_cset_link, cset_link); + struct list_head *l = it->task_pos; /* If the iterator cg is NULL, we have no tasks */ - if (!it->cset_link) + if (!it->cset_pos) return NULL; res = list_entry(l, struct task_struct, cg_list); @@ -2862,13 +3479,13 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it) */ l = l->next; - if (l == &link->cset->tasks) - l = link->cset->mg_tasks.next; + if (l == it->tasks_head) + l = it->mg_tasks_head->next; - if (l == &link->cset->mg_tasks) + if (l == it->mg_tasks_head) css_advance_task_iter(it); else - it->task = l; + it->task_pos = l; return res; } @@ -2921,7 +3538,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) * ->can_attach() fails. */ do { - css_task_iter_start(&from->dummy_css, &it); + css_task_iter_start(&from->self, &it); task = css_task_iter_next(&it); if (task) get_task_struct(task); @@ -3186,7 +3803,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type, if (!array) return -ENOMEM; /* now, populate the array */ - css_task_iter_start(&cgrp->dummy_css, &it); + css_task_iter_start(&cgrp->self, &it); while ((tsk = css_task_iter_next(&it))) { if (unlikely(n == length)) break; @@ -3248,7 +3865,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) /* * We aren't being called from kernfs and there's no guarantee on - * @kn->priv's validity. For this and css_tryget_from_dir(), + * @kn->priv's validity. For this and css_tryget_online_from_dir(), * @kn->priv is RCU safe. Let's do the RCU dancing. */ rcu_read_lock(); @@ -3260,7 +3877,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) } rcu_read_unlock(); - css_task_iter_start(&cgrp->dummy_css, &it); + css_task_iter_start(&cgrp->self, &it); while ((tsk = css_task_iter_next(&it))) { switch (tsk->state) { case TASK_RUNNING: @@ -3390,17 +4007,6 @@ static int cgroup_pidlist_show(struct seq_file *s, void *v) return seq_printf(s, "%d\n", *(int *)v); } -/* - * seq_operations functions for iterating on pidlists through seq_file - - * independent of whether it's tasks or procs - */ -static const struct seq_operations cgroup_pidlist_seq_operations = { - .start = cgroup_pidlist_start, - .stop = cgroup_pidlist_stop, - .next = cgroup_pidlist_next, - .show = cgroup_pidlist_show, -}; - static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css, struct cftype *cft) { @@ -3442,7 +4048,7 @@ static struct cftype cgroup_base_files[] = { .seq_stop = cgroup_pidlist_stop, .seq_show = cgroup_pidlist_show, .private = CGROUP_FILE_PROCS, - .write_u64 = cgroup_procs_write, + .write = cgroup_procs_write, .mode = S_IRUGO | S_IWUSR, }, { @@ -3456,6 +4062,27 @@ static struct cftype cgroup_base_files[] = { .flags = CFTYPE_ONLY_ON_ROOT, .seq_show = cgroup_sane_behavior_show, }, + { + .name = "cgroup.controllers", + .flags = CFTYPE_ONLY_ON_DFL | CFTYPE_ONLY_ON_ROOT, + .seq_show = cgroup_root_controllers_show, + }, + { + .name = "cgroup.controllers", + .flags = CFTYPE_ONLY_ON_DFL | CFTYPE_NOT_ON_ROOT, + .seq_show = cgroup_controllers_show, + }, + { + .name = "cgroup.subtree_control", + .flags = CFTYPE_ONLY_ON_DFL, + .seq_show = cgroup_subtree_control_show, + .write = cgroup_subtree_control_write, + }, + { + .name = "cgroup.populated", + .flags = CFTYPE_ONLY_ON_DFL | CFTYPE_NOT_ON_ROOT, + .seq_show = cgroup_populated_show, + }, /* * Historical crazy stuff. These don't have "cgroup." prefix and @@ -3470,7 +4097,7 @@ static struct cftype cgroup_base_files[] = { .seq_stop = cgroup_pidlist_stop, .seq_show = cgroup_pidlist_show, .private = CGROUP_FILE_TASKS, - .write_u64 = cgroup_tasks_write, + .write = cgroup_tasks_write, .mode = S_IRUGO | S_IWUSR, }, { @@ -3483,7 +4110,7 @@ static struct cftype cgroup_base_files[] = { .name = "release_agent", .flags = CFTYPE_INSANE | CFTYPE_ONLY_ON_ROOT, .seq_show = cgroup_release_agent_show, - .write_string = cgroup_release_agent_write, + .write = cgroup_release_agent_write, .max_write_len = PATH_MAX - 1, }, { } /* terminate */ @@ -3496,7 +4123,7 @@ static struct cftype cgroup_base_files[] = { * * On failure, no file is added. */ -static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask) +static int cgroup_populate_dir(struct cgroup *cgrp, unsigned int subsys_mask) { struct cgroup_subsys *ss; int i, ret = 0; @@ -3505,7 +4132,7 @@ static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask) for_each_subsys(ss, i) { struct cftype *cfts; - if (!test_bit(i, &subsys_mask)) + if (!(subsys_mask & (1 << i))) continue; list_for_each_entry(cfts, &ss->cfts, node) { @@ -3527,9 +4154,9 @@ err: * Implemented in kill_css(). * * 2. When the percpu_ref is confirmed to be visible as killed on all CPUs - * and thus css_tryget() is guaranteed to fail, the css can be offlined - * by invoking offline_css(). After offlining, the base ref is put. - * Implemented in css_killed_work_fn(). + * and thus css_tryget_online() is guaranteed to fail, the css can be + * offlined by invoking offline_css(). After offlining, the base ref is + * put. Implemented in css_killed_work_fn(). * * 3. When the percpu_ref reaches zero, the only possible remaining * accessors are inside RCU read sections. css_release() schedules the @@ -3548,11 +4175,37 @@ static void css_free_work_fn(struct work_struct *work) container_of(work, struct cgroup_subsys_state, destroy_work); struct cgroup *cgrp = css->cgroup; - if (css->parent) - css_put(css->parent); + if (css->ss) { + /* css free path */ + if (css->parent) + css_put(css->parent); - css->ss->css_free(css); - cgroup_put(cgrp); + css->ss->css_free(css); + cgroup_put(cgrp); + } else { + /* cgroup free path */ + atomic_dec(&cgrp->root->nr_cgrps); + cgroup_pidlist_destroy_all(cgrp); + + if (cgroup_parent(cgrp)) { + /* + * We get a ref to the parent, and put the ref when + * this cgroup is being freed, so it's guaranteed + * that the parent won't be destroyed before its + * children. + */ + cgroup_put(cgroup_parent(cgrp)); + kernfs_put(cgrp->kn); + kfree(cgrp); + } else { + /* + * This is root cgroup's refcnt reaching zero, + * which indicates that the root should be + * released. + */ + cgroup_destroy_root(cgrp->root); + } + } } static void css_free_rcu_fn(struct rcu_head *rcu_head) @@ -3564,26 +4217,59 @@ static void css_free_rcu_fn(struct rcu_head *rcu_head) queue_work(cgroup_destroy_wq, &css->destroy_work); } +static void css_release_work_fn(struct work_struct *work) +{ + struct cgroup_subsys_state *css = + container_of(work, struct cgroup_subsys_state, destroy_work); + struct cgroup_subsys *ss = css->ss; + struct cgroup *cgrp = css->cgroup; + + mutex_lock(&cgroup_mutex); + + css->flags |= CSS_RELEASED; + list_del_rcu(&css->sibling); + + if (ss) { + /* css release path */ + cgroup_idr_remove(&ss->css_idr, css->id); + } else { + /* cgroup release path */ + cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id); + cgrp->id = -1; + } + + mutex_unlock(&cgroup_mutex); + + call_rcu(&css->rcu_head, css_free_rcu_fn); +} + static void css_release(struct percpu_ref *ref) { struct cgroup_subsys_state *css = container_of(ref, struct cgroup_subsys_state, refcnt); - RCU_INIT_POINTER(css->cgroup->subsys[css->ss->id], NULL); - call_rcu(&css->rcu_head, css_free_rcu_fn); + INIT_WORK(&css->destroy_work, css_release_work_fn); + queue_work(cgroup_destroy_wq, &css->destroy_work); } -static void init_css(struct cgroup_subsys_state *css, struct cgroup_subsys *ss, - struct cgroup *cgrp) +static void init_and_link_css(struct cgroup_subsys_state *css, + struct cgroup_subsys *ss, struct cgroup *cgrp) { + lockdep_assert_held(&cgroup_mutex); + + cgroup_get(cgrp); + + memset(css, 0, sizeof(*css)); css->cgroup = cgrp; css->ss = ss; - css->flags = 0; + INIT_LIST_HEAD(&css->sibling); + INIT_LIST_HEAD(&css->children); + css->serial_nr = css_serial_nr_next++; - if (cgrp->parent) - css->parent = cgroup_css(cgrp->parent, ss); - else - css->flags |= CSS_ROOT; + if (cgroup_parent(cgrp)) { + css->parent = cgroup_css(cgroup_parent(cgrp), ss); + css_get(css->parent); + } BUG_ON(cgroup_css(cgrp, ss)); } @@ -3594,14 +4280,12 @@ static int online_css(struct cgroup_subsys_state *css) struct cgroup_subsys *ss = css->ss; int ret = 0; - lockdep_assert_held(&cgroup_tree_mutex); lockdep_assert_held(&cgroup_mutex); if (ss->css_online) ret = ss->css_online(css); if (!ret) { css->flags |= CSS_ONLINE; - css->cgroup->nr_css++; rcu_assign_pointer(css->cgroup->subsys[ss->id], css); } return ret; @@ -3612,7 +4296,6 @@ static void offline_css(struct cgroup_subsys_state *css) { struct cgroup_subsys *ss = css->ss; - lockdep_assert_held(&cgroup_tree_mutex); lockdep_assert_held(&cgroup_mutex); if (!(css->flags & CSS_ONLINE)) @@ -3622,8 +4305,9 @@ static void offline_css(struct cgroup_subsys_state *css) ss->css_offline(css); css->flags &= ~CSS_ONLINE; - css->cgroup->nr_css--; - RCU_INIT_POINTER(css->cgroup->subsys[ss->id], css); + RCU_INIT_POINTER(css->cgroup->subsys[ss->id], NULL); + + wake_up_all(&css->cgroup->offline_waitq); } /** @@ -3637,111 +4321,102 @@ static void offline_css(struct cgroup_subsys_state *css) */ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss) { - struct cgroup *parent = cgrp->parent; + struct cgroup *parent = cgroup_parent(cgrp); + struct cgroup_subsys_state *parent_css = cgroup_css(parent, ss); struct cgroup_subsys_state *css; int err; lockdep_assert_held(&cgroup_mutex); - css = ss->css_alloc(cgroup_css(parent, ss)); + css = ss->css_alloc(parent_css); if (IS_ERR(css)) return PTR_ERR(css); + init_and_link_css(css, ss, cgrp); + err = percpu_ref_init(&css->refcnt, css_release); if (err) goto err_free_css; - init_css(css, ss, cgrp); + err = cgroup_idr_alloc(&ss->css_idr, NULL, 2, 0, GFP_NOWAIT); + if (err < 0) + goto err_free_percpu_ref; + css->id = err; err = cgroup_populate_dir(cgrp, 1 << ss->id); if (err) - goto err_free_percpu_ref; + goto err_free_id; + + /* @css is ready to be brought online now, make it visible */ + list_add_tail_rcu(&css->sibling, &parent_css->children); + cgroup_idr_replace(&ss->css_idr, css, css->id); err = online_css(css); if (err) - goto err_clear_dir; - - cgroup_get(cgrp); - css_get(css->parent); - - cgrp->subsys_mask |= 1 << ss->id; + goto err_list_del; if (ss->broken_hierarchy && !ss->warned_broken_hierarchy && - parent->parent) { - pr_warning("cgroup: %s (%d) created nested cgroup for controller \"%s\" which has incomplete hierarchy support. Nested cgroups may change behavior in the future.\n", - current->comm, current->pid, ss->name); + cgroup_parent(parent)) { + pr_warn("%s (%d) created nested cgroup for controller \"%s\" which has incomplete hierarchy support. Nested cgroups may change behavior in the future.\n", + current->comm, current->pid, ss->name); if (!strcmp(ss->name, "memory")) - pr_warning("cgroup: \"memory\" requires setting use_hierarchy to 1 on the root.\n"); + pr_warn("\"memory\" requires setting use_hierarchy to 1 on the root\n"); ss->warned_broken_hierarchy = true; } return 0; -err_clear_dir: +err_list_del: + list_del_rcu(&css->sibling); cgroup_clear_dir(css->cgroup, 1 << css->ss->id); +err_free_id: + cgroup_idr_remove(&ss->css_idr, css->id); err_free_percpu_ref: percpu_ref_cancel_init(&css->refcnt); err_free_css: - ss->css_free(css); + call_rcu(&css->rcu_head, css_free_rcu_fn); return err; } -/** - * cgroup_create - create a cgroup - * @parent: cgroup that will be parent of the new cgroup - * @name: name of the new cgroup - * @mode: mode to set on new cgroup - */ -static long cgroup_create(struct cgroup *parent, const char *name, - umode_t mode) +static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, + umode_t mode) { - struct cgroup *cgrp; - struct cgroup_root *root = parent->root; - int ssid, err; + struct cgroup *parent, *cgrp; + struct cgroup_root *root; struct cgroup_subsys *ss; struct kernfs_node *kn; + int ssid, ret; - /* - * XXX: The default hierarchy isn't fully implemented yet. Block - * !root cgroup creation on it for now. - */ - if (root == &cgrp_dfl_root) - return -EINVAL; + parent = cgroup_kn_lock_live(parent_kn); + if (!parent) + return -ENODEV; + root = parent->root; /* allocate the cgroup and its ID, 0 is reserved for the root */ cgrp = kzalloc(sizeof(*cgrp), GFP_KERNEL); - if (!cgrp) - return -ENOMEM; - - mutex_lock(&cgroup_tree_mutex); - - /* - * Only live parents can have children. Note that the liveliness - * check isn't strictly necessary because cgroup_mkdir() and - * cgroup_rmdir() are fully synchronized by i_mutex; however, do it - * anyway so that locking is contained inside cgroup proper and we - * don't get nasty surprises if we ever grow another caller. - */ - if (!cgroup_lock_live_group(parent)) { - err = -ENODEV; - goto err_unlock_tree; + if (!cgrp) { + ret = -ENOMEM; + goto out_unlock; } + ret = percpu_ref_init(&cgrp->self.refcnt, css_release); + if (ret) + goto out_free_cgrp; + /* * Temporarily set the pointer to NULL, so idr_find() won't return * a half-baked cgroup. */ - cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL); + cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_NOWAIT); if (cgrp->id < 0) { - err = -ENOMEM; - goto err_unlock; + ret = -ENOMEM; + goto out_cancel_ref; } init_cgroup_housekeeping(cgrp); - cgrp->parent = parent; - cgrp->dummy_css.parent = &parent->dummy_css; - cgrp->root = parent->root; + cgrp->self.parent = &parent->self; + cgrp->root = root; if (notify_on_release(parent)) set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); @@ -3752,8 +4427,8 @@ static long cgroup_create(struct cgroup *parent, const char *name, /* create the directory */ kn = kernfs_create_dir(parent->kn, name, mode, cgrp); if (IS_ERR(kn)) { - err = PTR_ERR(kn); - goto err_free_id; + ret = PTR_ERR(kn); + goto out_free_id; } cgrp->kn = kn; @@ -3763,10 +4438,10 @@ static long cgroup_create(struct cgroup *parent, const char *name, */ kernfs_get(kn); - cgrp->serial_nr = cgroup_serial_nr_next++; + cgrp->self.serial_nr = css_serial_nr_next++; /* allocation complete, commit to creation */ - list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children); + list_add_tail_rcu(&cgrp->self.sibling, &cgroup_parent(cgrp)->self.children); atomic_inc(&root->nr_cgrps); cgroup_get(parent); @@ -3774,107 +4449,66 @@ static long cgroup_create(struct cgroup *parent, const char *name, * @cgrp is now fully operational. If something fails after this * point, it'll be released via the normal destruction path. */ - idr_replace(&root->cgroup_idr, cgrp, cgrp->id); + cgroup_idr_replace(&root->cgroup_idr, cgrp, cgrp->id); - err = cgroup_kn_set_ugid(kn); - if (err) - goto err_destroy; + ret = cgroup_kn_set_ugid(kn); + if (ret) + goto out_destroy; - err = cgroup_addrm_files(cgrp, cgroup_base_files, true); - if (err) - goto err_destroy; + ret = cgroup_addrm_files(cgrp, cgroup_base_files, true); + if (ret) + goto out_destroy; /* let's create and online css's */ for_each_subsys(ss, ssid) { - if (root->cgrp.subsys_mask & (1 << ssid)) { - err = create_css(cgrp, ss); - if (err) - goto err_destroy; + if (parent->child_subsys_mask & (1 << ssid)) { + ret = create_css(cgrp, ss); + if (ret) + goto out_destroy; } } - kernfs_activate(kn); + /* + * On the default hierarchy, a child doesn't automatically inherit + * child_subsys_mask from the parent. Each is configured manually. + */ + if (!cgroup_on_dfl(cgrp)) + cgrp->child_subsys_mask = parent->child_subsys_mask; - mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); + kernfs_activate(kn); - return 0; + ret = 0; + goto out_unlock; -err_free_id: - idr_remove(&root->cgroup_idr, cgrp->id); -err_unlock: - mutex_unlock(&cgroup_mutex); -err_unlock_tree: - mutex_unlock(&cgroup_tree_mutex); +out_free_id: + cgroup_idr_remove(&root->cgroup_idr, cgrp->id); +out_cancel_ref: + percpu_ref_cancel_init(&cgrp->self.refcnt); +out_free_cgrp: kfree(cgrp); - return err; +out_unlock: + cgroup_kn_unlock(parent_kn); + return ret; -err_destroy: +out_destroy: cgroup_destroy_locked(cgrp); - mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); - return err; -} - -static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, - umode_t mode) -{ - struct cgroup *parent = parent_kn->priv; - int ret; - - /* - * cgroup_create() grabs cgroup_tree_mutex which nests outside - * kernfs active_ref and cgroup_create() already synchronizes - * properly against removal through cgroup_lock_live_group(). - * Break it before calling cgroup_create(). - */ - cgroup_get(parent); - kernfs_break_active_protection(parent_kn); - - ret = cgroup_create(parent, name, mode); - - kernfs_unbreak_active_protection(parent_kn); - cgroup_put(parent); - return ret; + goto out_unlock; } /* * This is called when the refcnt of a css is confirmed to be killed. - * css_tryget() is now guaranteed to fail. + * css_tryget_online() is now guaranteed to fail. Tell the subsystem to + * initate destruction and put the css ref from kill_css(). */ static void css_killed_work_fn(struct work_struct *work) { struct cgroup_subsys_state *css = container_of(work, struct cgroup_subsys_state, destroy_work); - struct cgroup *cgrp = css->cgroup; - mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); - - /* - * css_tryget() is guaranteed to fail now. Tell subsystems to - * initate destruction. - */ offline_css(css); - - /* - * If @cgrp is marked dead, it's waiting for refs of all css's to - * be disabled before proceeding to the second phase of cgroup - * destruction. If we are the last one, kick it off. - */ - if (!cgrp->nr_css && cgroup_is_dead(cgrp)) - cgroup_destroy_css_killed(cgrp); - mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); - /* - * Put the css refs from kill_css(). Each css holds an extra - * reference to the cgroup's dentry and cgroup removal proceeds - * regardless of css refs. On the last put of each css, whenever - * that may be, the extra dentry ref is put so that dentry - * destruction happens only after all css's are released. - */ css_put(css); } @@ -3888,9 +4522,18 @@ static void css_killed_ref_fn(struct percpu_ref *ref) queue_work(cgroup_destroy_wq, &css->destroy_work); } -static void __kill_css(struct cgroup_subsys_state *css) +/** + * kill_css - destroy a css + * @css: css to destroy + * + * This function initiates destruction of @css by removing cgroup interface + * files and putting its base reference. ->css_offline() will be invoked + * asynchronously once css_tryget_online() is guaranteed to fail and when + * the reference count reaches zero, @css will be released. + */ +static void kill_css(struct cgroup_subsys_state *css) { - lockdep_assert_held(&cgroup_tree_mutex); + lockdep_assert_held(&cgroup_mutex); /* * This must happen before css is disassociated with its cgroup. @@ -3907,7 +4550,7 @@ static void __kill_css(struct cgroup_subsys_state *css) /* * cgroup core guarantees that, by the time ->css_offline() is * invoked, no new css reference will be given out via - * css_tryget(). We can't simply call percpu_ref_kill() and + * css_tryget_online(). We can't simply call percpu_ref_kill() and * proceed to offlining css's because percpu_ref_kill() doesn't * guarantee that the ref is seen as killed on all CPUs on return. * @@ -3918,36 +4561,14 @@ static void __kill_css(struct cgroup_subsys_state *css) } /** - * kill_css - destroy a css - * @css: css to destroy - * - * This function initiates destruction of @css by removing cgroup interface - * files and putting its base reference. ->css_offline() will be invoked - * asynchronously once css_tryget() is guaranteed to fail and when the - * reference count reaches zero, @css will be released. - */ -static void kill_css(struct cgroup_subsys_state *css) -{ - struct cgroup *cgrp = css->cgroup; - - lockdep_assert_held(&cgroup_tree_mutex); - - /* if already killed, noop */ - if (cgrp->subsys_mask & (1 << css->ss->id)) { - cgrp->subsys_mask &= ~(1 << css->ss->id); - __kill_css(css); - } -} - -/** * cgroup_destroy_locked - the first stage of cgroup destruction * @cgrp: cgroup to be destroyed * * css's make use of percpu refcnts whose killing latency shouldn't be * exposed to userland and are RCU protected. Also, cgroup core needs to - * guarantee that css_tryget() won't succeed by the time ->css_offline() is - * invoked. To satisfy all the requirements, destruction is implemented in - * the following two steps. + * guarantee that css_tryget_online() won't succeed by the time + * ->css_offline() is invoked. To satisfy all the requirements, + * destruction is implemented in the following two steps. * * s1. Verify @cgrp can be destroyed and mark it dying. Remove all * userland visible parts and start killing the percpu refcnts of @@ -3966,12 +4587,10 @@ static void kill_css(struct cgroup_subsys_state *css) static int cgroup_destroy_locked(struct cgroup *cgrp) __releases(&cgroup_mutex) __acquires(&cgroup_mutex) { - struct cgroup *child; struct cgroup_subsys_state *css; bool empty; int ssid; - lockdep_assert_held(&cgroup_tree_mutex); lockdep_assert_held(&cgroup_mutex); /* @@ -3985,127 +4604,68 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) return -EBUSY; /* - * Make sure there's no live children. We can't test ->children - * emptiness as dead children linger on it while being destroyed; - * otherwise, "rmdir parent/child parent" may fail with -EBUSY. + * Make sure there's no live children. We can't test emptiness of + * ->self.children as dead children linger on it while being + * drained; otherwise, "rmdir parent/child parent" may fail. */ - empty = true; - rcu_read_lock(); - list_for_each_entry_rcu(child, &cgrp->children, sibling) { - empty = cgroup_is_dead(child); - if (!empty) - break; - } - rcu_read_unlock(); - if (!empty) + if (css_has_online_children(&cgrp->self)) return -EBUSY; /* * Mark @cgrp dead. This prevents further task migration and child - * creation by disabling cgroup_lock_live_group(). Note that - * CGRP_DEAD assertion is depended upon by css_next_child() to - * resume iteration after dropping RCU read lock. See - * css_next_child() for details. + * creation by disabling cgroup_lock_live_group(). */ - set_bit(CGRP_DEAD, &cgrp->flags); + cgrp->self.flags &= ~CSS_ONLINE; - /* - * Initiate massacre of all css's. cgroup_destroy_css_killed() - * will be invoked to perform the rest of destruction once the - * percpu refs of all css's are confirmed to be killed. This - * involves removing the subsystem's files, drop cgroup_mutex. - */ - mutex_unlock(&cgroup_mutex); + /* initiate massacre of all css's */ for_each_css(css, ssid, cgrp) kill_css(css); - mutex_lock(&cgroup_mutex); - /* CGRP_DEAD is set, remove from ->release_list for the last time */ + /* CSS_ONLINE is clear, remove from ->release_list for the last time */ raw_spin_lock(&release_list_lock); if (!list_empty(&cgrp->release_list)) list_del_init(&cgrp->release_list); raw_spin_unlock(&release_list_lock); /* - * If @cgrp has css's attached, the second stage of cgroup - * destruction is kicked off from css_killed_work_fn() after the - * refs of all attached css's are killed. If @cgrp doesn't have - * any css, we kick it off here. + * Remove @cgrp directory along with the base files. @cgrp has an + * extra ref on its kn. */ - if (!cgrp->nr_css) - cgroup_destroy_css_killed(cgrp); + kernfs_remove(cgrp->kn); - /* remove @cgrp directory along with the base files */ - mutex_unlock(&cgroup_mutex); - - /* - * There are two control paths which try to determine cgroup from - * dentry without going through kernfs - cgroupstats_build() and - * css_tryget_from_dir(). Those are supported by RCU protecting - * clearing of cgrp->kn->priv backpointer, which should happen - * after all files under it have been removed. - */ - kernfs_remove(cgrp->kn); /* @cgrp has an extra ref on its kn */ - RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL); + set_bit(CGRP_RELEASABLE, &cgroup_parent(cgrp)->flags); + check_for_release(cgroup_parent(cgrp)); - mutex_lock(&cgroup_mutex); + /* put the base reference */ + percpu_ref_kill(&cgrp->self.refcnt); return 0; }; -/** - * cgroup_destroy_css_killed - the second step of cgroup destruction - * @work: cgroup->destroy_free_work - * - * This function is invoked from a work item for a cgroup which is being - * destroyed after all css's are offlined and performs the rest of - * destruction. This is the second step of destruction described in the - * comment above cgroup_destroy_locked(). - */ -static void cgroup_destroy_css_killed(struct cgroup *cgrp) -{ - struct cgroup *parent = cgrp->parent; - - lockdep_assert_held(&cgroup_tree_mutex); - lockdep_assert_held(&cgroup_mutex); - - /* delete this cgroup from parent->children */ - list_del_rcu(&cgrp->sibling); - - cgroup_put(cgrp); - - set_bit(CGRP_RELEASABLE, &parent->flags); - check_for_release(parent); -} - static int cgroup_rmdir(struct kernfs_node *kn) { - struct cgroup *cgrp = kn->priv; + struct cgroup *cgrp; int ret = 0; - /* - * This is self-destruction but @kn can't be removed while this - * callback is in progress. Let's break active protection. Once - * the protection is broken, @cgrp can be destroyed at any point. - * Pin it so that it stays accessible. - */ - cgroup_get(cgrp); - kernfs_break_active_protection(kn); + cgrp = cgroup_kn_lock_live(kn); + if (!cgrp) + return 0; + cgroup_get(cgrp); /* for @kn->priv clearing */ - mutex_lock(&cgroup_tree_mutex); - mutex_lock(&cgroup_mutex); + ret = cgroup_destroy_locked(cgrp); + + cgroup_kn_unlock(kn); /* - * @cgrp might already have been destroyed while we're trying to - * grab the mutexes. + * There are two control paths which try to determine cgroup from + * dentry without going through kernfs - cgroupstats_build() and + * css_tryget_online_from_dir(). Those are supported by RCU + * protecting clearing of cgrp->kn->priv backpointer, which should + * happen after all files under it have been removed. */ - if (!cgroup_is_dead(cgrp)) - ret = cgroup_destroy_locked(cgrp); - - mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); + if (!ret) + RCU_INIT_POINTER(*(void __rcu __force **)&kn->priv, NULL); - kernfs_unbreak_active_protection(kn); cgroup_put(cgrp); return ret; } @@ -4118,15 +4678,15 @@ static struct kernfs_syscall_ops cgroup_kf_syscall_ops = { .rename = cgroup_rename, }; -static void __init cgroup_init_subsys(struct cgroup_subsys *ss) +static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early) { struct cgroup_subsys_state *css; printk(KERN_INFO "Initializing cgroup subsys %s\n", ss->name); - mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); + idr_init(&ss->css_idr); INIT_LIST_HEAD(&ss->cfts); /* Create the root cgroup state for this subsystem */ @@ -4134,7 +4694,21 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) css = ss->css_alloc(cgroup_css(&cgrp_dfl_root.cgrp, ss)); /* We don't handle early failures gracefully */ BUG_ON(IS_ERR(css)); - init_css(css, ss, &cgrp_dfl_root.cgrp); + init_and_link_css(css, ss, &cgrp_dfl_root.cgrp); + + /* + * Root csses are never destroyed and we can't initialize + * percpu_ref during early init. Disable refcnting. + */ + css->flags |= CSS_NO_REF; + + if (early) { + /* allocation can't be done safely during early init */ + css->id = 1; + } else { + css->id = cgroup_idr_alloc(&ss->css_idr, css, 1, 2, GFP_KERNEL); + BUG_ON(css->id < 0); + } /* Update the init_css_set to contain a subsys * pointer to this state - since the subsystem is @@ -4151,10 +4725,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) BUG_ON(online_css(css)); - cgrp_dfl_root.cgrp.subsys_mask |= 1 << ss->id; - mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); } /** @@ -4171,6 +4742,8 @@ int __init cgroup_init_early(void) int i; init_cgroup_root(&cgrp_dfl_root, &opts); + cgrp_dfl_root.cgrp.self.flags |= CSS_NO_REF; + RCU_INIT_POINTER(init_task.cgroups, &init_css_set); for_each_subsys(ss, i) { @@ -4185,7 +4758,7 @@ int __init cgroup_init_early(void) ss->name = cgroup_subsys_name[i]; if (ss->early_init) - cgroup_init_subsys(ss); + cgroup_init_subsys(ss, true); } return 0; } @@ -4204,7 +4777,6 @@ int __init cgroup_init(void) BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files)); - mutex_lock(&cgroup_tree_mutex); mutex_lock(&cgroup_mutex); /* Add init_css_set to the hash table */ @@ -4214,18 +4786,31 @@ int __init cgroup_init(void) BUG_ON(cgroup_setup_root(&cgrp_dfl_root, 0)); mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); for_each_subsys(ss, ssid) { - if (!ss->early_init) - cgroup_init_subsys(ss); + if (ss->early_init) { + struct cgroup_subsys_state *css = + init_css_set.subsys[ss->id]; + + css->id = cgroup_idr_alloc(&ss->css_idr, css, 1, 2, + GFP_KERNEL); + BUG_ON(css->id < 0); + } else { + cgroup_init_subsys(ss, false); + } + + list_add_tail(&init_css_set.e_cset_node[ssid], + &cgrp_dfl_root.cgrp.e_csets[ssid]); /* - * cftype registration needs kmalloc and can't be done - * during early_init. Register base cftypes separately. + * Setting dfl_root subsys_mask needs to consider the + * disabled flag and cftype registration needs kmalloc, + * both of which aren't available during early_init. */ - if (ss->base_cftypes) + if (!ss->disabled) { + cgrp_dfl_root.subsys_mask |= 1 << ss->id; WARN_ON(cgroup_add_cftypes(ss, ss->base_cftypes)); + } } cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj); @@ -4308,7 +4893,7 @@ int proc_cgroup_show(struct seq_file *m, void *v) seq_printf(m, "%d:", root->hierarchy_id); for_each_subsys(ss, ssid) - if (root->cgrp.subsys_mask & (1 << ssid)) + if (root->subsys_mask & (1 << ssid)) seq_printf(m, "%s%s", count++ ? "," : "", ss->name); if (strlen(root->name)) seq_printf(m, "%sname=%s", count ? "," : "", @@ -4503,8 +5088,8 @@ void cgroup_exit(struct task_struct *tsk) static void check_for_release(struct cgroup *cgrp) { - if (cgroup_is_releasable(cgrp) && - list_empty(&cgrp->cset_links) && list_empty(&cgrp->children)) { + if (cgroup_is_releasable(cgrp) && list_empty(&cgrp->cset_links) && + !css_has_online_children(&cgrp->self)) { /* * Control Group is currently removeable. If it's not * already queued for a userspace notification, queue @@ -4621,7 +5206,7 @@ static int __init cgroup_disable(char *str) __setup("cgroup_disable=", cgroup_disable); /** - * css_tryget_from_dir - get corresponding css from the dentry of a cgroup dir + * css_tryget_online_from_dir - get corresponding css from a cgroup dentry * @dentry: directory dentry of interest * @ss: subsystem of interest * @@ -4629,8 +5214,8 @@ __setup("cgroup_disable=", cgroup_disable); * to get the corresponding css and return it. If such css doesn't exist * or can't be pinned, an ERR_PTR value is returned. */ -struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry, - struct cgroup_subsys *ss) +struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, + struct cgroup_subsys *ss) { struct kernfs_node *kn = kernfs_node_from_dentry(dentry); struct cgroup_subsys_state *css = NULL; @@ -4646,13 +5231,13 @@ struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry, /* * This path doesn't originate from kernfs and @kn could already * have been or be removed at any point. @kn->priv is RCU - * protected for this access. See destroy_locked() for details. + * protected for this access. See cgroup_rmdir() for details. */ cgrp = rcu_dereference(kn->priv); if (cgrp) css = cgroup_css(cgrp, ss); - if (!css || !css_tryget(css)) + if (!css || !css_tryget_online(css)) css = ERR_PTR(-ENOENT); rcu_read_unlock(); @@ -4669,14 +5254,8 @@ struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry, */ struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss) { - struct cgroup *cgrp; - - cgroup_assert_mutexes_or_rcu_locked(); - - cgrp = idr_find(&ss->root->cgroup_idr, id); - if (cgrp) - return cgroup_css(cgrp, ss); - return NULL; + WARN_ON_ONCE(!rcu_read_lock_held()); + return idr_find(&ss->css_idr, id); } #ifdef CONFIG_CGROUP_DEBUG diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 345628c78b5b..a79e40f9d700 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -59,7 +59,7 @@ static inline struct freezer *task_freezer(struct task_struct *task) static struct freezer *parent_freezer(struct freezer *freezer) { - return css_freezer(css_parent(&freezer->css)); + return css_freezer(freezer->css.parent); } bool cgroup_freezing(struct task_struct *task) @@ -73,10 +73,6 @@ bool cgroup_freezing(struct task_struct *task) return ret; } -/* - * cgroups_write_string() limits the size of freezer state strings to - * CGROUP_LOCAL_BUFFER_SIZE - */ static const char *freezer_state_strs(unsigned int state) { if (state & CGROUP_FROZEN) @@ -304,7 +300,7 @@ static int freezer_read(struct seq_file *m, void *v) /* update states bottom-up */ css_for_each_descendant_post(pos, css) { - if (!css_tryget(pos)) + if (!css_tryget_online(pos)) continue; rcu_read_unlock(); @@ -404,7 +400,7 @@ static void freezer_change_state(struct freezer *freezer, bool freeze) struct freezer *pos_f = css_freezer(pos); struct freezer *parent = parent_freezer(pos_f); - if (!css_tryget(pos)) + if (!css_tryget_online(pos)) continue; rcu_read_unlock(); @@ -423,20 +419,22 @@ static void freezer_change_state(struct freezer *freezer, bool freeze) mutex_unlock(&freezer_mutex); } -static int freezer_write(struct cgroup_subsys_state *css, struct cftype *cft, - char *buffer) +static ssize_t freezer_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) { bool freeze; - if (strcmp(buffer, freezer_state_strs(0)) == 0) + buf = strstrip(buf); + + if (strcmp(buf, freezer_state_strs(0)) == 0) freeze = false; - else if (strcmp(buffer, freezer_state_strs(CGROUP_FROZEN)) == 0) + else if (strcmp(buf, freezer_state_strs(CGROUP_FROZEN)) == 0) freeze = true; else return -EINVAL; - freezer_change_state(css_freezer(css), freeze); - return 0; + freezer_change_state(css_freezer(of_css(of)), freeze); + return nbytes; } static u64 freezer_self_freezing_read(struct cgroup_subsys_state *css, @@ -460,7 +458,7 @@ static struct cftype files[] = { .name = "state", .flags = CFTYPE_NOT_ON_ROOT, .seq_show = freezer_read, - .write_string = freezer_write, + .write = freezer_write, }, { .name = "self_freezing", diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 019d45008448..5664985c46a0 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -19,6 +19,7 @@ #include <linux/sched.h> #include <linux/hardirq.h> #include <linux/export.h> +#include <linux/kprobes.h> #define CREATE_TRACE_POINTS #include <trace/events/context_tracking.h> @@ -104,6 +105,7 @@ void context_tracking_user_enter(void) } local_irq_restore(flags); } +NOKPROBE_SYMBOL(context_tracking_user_enter); #ifdef CONFIG_PREEMPT /** @@ -181,6 +183,7 @@ void context_tracking_user_exit(void) } local_irq_restore(flags); } +NOKPROBE_SYMBOL(context_tracking_user_exit); /** * __context_tracking_task_switch - context switch the syscall callbacks diff --git a/kernel/cpu.c b/kernel/cpu.c index acf791c55b71..a343bde710b1 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -20,6 +20,7 @@ #include <linux/gfp.h> #include <linux/suspend.h> #include <linux/lockdep.h> +#include <trace/events/power.h> #include "smpboot.h" @@ -520,7 +521,9 @@ int disable_nonboot_cpus(void) for_each_online_cpu(cpu) { if (cpu == first_cpu) continue; + trace_suspend_resume(TPS("CPU_OFF"), cpu, true); error = _cpu_down(cpu, 1); + trace_suspend_resume(TPS("CPU_OFF"), cpu, false); if (!error) cpumask_set_cpu(cpu, frozen_cpus); else { @@ -563,7 +566,9 @@ void __ref enable_nonboot_cpus(void) arch_enable_nonboot_cpus_begin(); for_each_cpu(cpu, frozen_cpus) { + trace_suspend_resume(TPS("CPU_ON"), cpu, true); error = _cpu_up(cpu, 1); + trace_suspend_resume(TPS("CPU_ON"), cpu, false); if (!error) { pr_info("CPU%d is up\n", cpu); continue; diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 130017843899..116a4164720a 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -119,7 +119,7 @@ static inline struct cpuset *task_cs(struct task_struct *task) static inline struct cpuset *parent_cs(struct cpuset *cs) { - return css_cs(css_parent(&cs->css)); + return css_cs(cs->css.parent); } #ifdef CONFIG_NUMA @@ -691,11 +691,8 @@ restart: if (nslot == ndoms) { static int warnings = 10; if (warnings) { - printk(KERN_WARNING - "rebuild_sched_domains confused:" - " nslot %d, ndoms %d, csn %d, i %d," - " apn %d\n", - nslot, ndoms, csn, i, apn); + pr_warn("rebuild_sched_domains confused: nslot %d, ndoms %d, csn %d, i %d, apn %d\n", + nslot, ndoms, csn, i, apn); warnings--; } continue; @@ -870,7 +867,7 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs, bool update_root) continue; } } - if (!css_tryget(&cp->css)) + if (!css_tryget_online(&cp->css)) continue; rcu_read_unlock(); @@ -885,6 +882,7 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs, bool update_root) /** * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it * @cs: the cpuset to consider + * @trialcs: trial cpuset * @buf: buffer of cpu numbers written to this cpuset */ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, @@ -1105,7 +1103,7 @@ static void update_tasks_nodemask_hier(struct cpuset *root_cs, bool update_root) continue; } } - if (!css_tryget(&cp->css)) + if (!css_tryget_online(&cp->css)) continue; rcu_read_unlock(); @@ -1183,7 +1181,13 @@ done: int current_cpuset_is_being_rebound(void) { - return task_cs(current) == cpuset_being_rebound; + int ret; + + rcu_read_lock(); + ret = task_cs(current) == cpuset_being_rebound; + rcu_read_unlock(); + + return ret; } static int update_relax_domain_level(struct cpuset *cs, s64 val) @@ -1600,13 +1604,15 @@ out_unlock: /* * Common handling for a write to a "cpus" or "mems" file. */ -static int cpuset_write_resmask(struct cgroup_subsys_state *css, - struct cftype *cft, char *buf) +static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) { - struct cpuset *cs = css_cs(css); + struct cpuset *cs = css_cs(of_css(of)); struct cpuset *trialcs; int retval = -ENODEV; + buf = strstrip(buf); + /* * CPU or memory hotunplug may leave @cs w/o any execution * resources, in which case the hotplug code asynchronously updates @@ -1617,7 +1623,17 @@ static int cpuset_write_resmask(struct cgroup_subsys_state *css, * resources, wait for the previously scheduled operations before * proceeding, so that we don't end up keep removing tasks added * after execution capability is restored. + * + * cpuset_hotplug_work calls back into cgroup core via + * cgroup_transfer_tasks() and waiting for it from a cgroupfs + * operation like this one can lead to a deadlock through kernfs + * active_ref protection. Let's break the protection. Losing the + * protection is okay as we check whether @cs is online after + * grabbing cpuset_mutex anyway. This only happens on the legacy + * hierarchies. */ + css_get(&cs->css); + kernfs_break_active_protection(of->kn); flush_work(&cpuset_hotplug_work); mutex_lock(&cpuset_mutex); @@ -1630,7 +1646,7 @@ static int cpuset_write_resmask(struct cgroup_subsys_state *css, goto out_unlock; } - switch (cft->private) { + switch (of_cft(of)->private) { case FILE_CPULIST: retval = update_cpumask(cs, trialcs, buf); break; @@ -1645,7 +1661,9 @@ static int cpuset_write_resmask(struct cgroup_subsys_state *css, free_trial_cpuset(trialcs); out_unlock: mutex_unlock(&cpuset_mutex); - return retval; + kernfs_unbreak_active_protection(of->kn); + css_put(&cs->css); + return retval ?: nbytes; } /* @@ -1747,7 +1765,7 @@ static struct cftype files[] = { { .name = "cpus", .seq_show = cpuset_common_seq_show, - .write_string = cpuset_write_resmask, + .write = cpuset_write_resmask, .max_write_len = (100U + 6 * NR_CPUS), .private = FILE_CPULIST, }, @@ -1755,7 +1773,7 @@ static struct cftype files[] = { { .name = "mems", .seq_show = cpuset_common_seq_show, - .write_string = cpuset_write_resmask, + .write = cpuset_write_resmask, .max_write_len = (100U + 6 * MAX_NUMNODES), .private = FILE_MEMLIST, }, @@ -2011,7 +2029,7 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs) parent = parent_cs(parent); if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) { - printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset "); + pr_err("cpuset: failed to transfer tasks out of empty cpuset "); pr_cont_cgroup_name(cs->css.cgroup); pr_cont("\n"); } @@ -2149,7 +2167,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) rcu_read_lock(); cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) { - if (cs == &top_cpuset || !css_tryget(&cs->css)) + if (cs == &top_cpuset || !css_tryget_online(&cs->css)) continue; rcu_read_unlock(); @@ -2530,7 +2548,7 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, /** * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed - * @task: pointer to task_struct of some task. + * @tsk: pointer to task_struct of some task. * * Description: Prints @task's name, cpuset name, and cached copy of its * mems_allowed to the kernel log. @@ -2548,7 +2566,7 @@ void cpuset_print_task_mems_allowed(struct task_struct *tsk) cgrp = task_cs(tsk)->css.cgroup; nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN, tsk->mems_allowed); - printk(KERN_INFO "%s cpuset=", tsk->comm); + pr_info("%s cpuset=", tsk->comm); pr_cont_cgroup_name(cgrp); pr_cont(" mems_allowed=%s\n", cpuset_nodelist); @@ -2640,10 +2658,10 @@ out: /* Display task mems_allowed in /proc/<pid>/status file. */ void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task) { - seq_printf(m, "Mems_allowed:\t"); + seq_puts(m, "Mems_allowed:\t"); seq_nodemask(m, &task->mems_allowed); - seq_printf(m, "\n"); - seq_printf(m, "Mems_allowed_list:\t"); + seq_puts(m, "\n"); + seq_puts(m, "Mems_allowed_list:\t"); seq_nodemask_list(m, &task->mems_allowed); - seq_printf(m, "\n"); + seq_puts(m, "\n"); } diff --git a/kernel/events/core.c b/kernel/events/core.c index 689237a0c5e8..a33d9a2bcbd7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -40,6 +40,7 @@ #include <linux/mm_types.h> #include <linux/cgroup.h> #include <linux/module.h> +#include <linux/mman.h> #include "internal.h" @@ -608,7 +609,8 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event, if (!f.file) return -EBADF; - css = css_tryget_from_dir(f.file->f_dentry, &perf_event_cgrp_subsys); + css = css_tryget_online_from_dir(f.file->f_dentry, + &perf_event_cgrp_subsys); if (IS_ERR(css)) { ret = PTR_ERR(css); goto out; @@ -2973,6 +2975,22 @@ out: local_irq_restore(flags); } +void perf_event_exec(void) +{ + struct perf_event_context *ctx; + int ctxn; + + rcu_read_lock(); + for_each_task_context_nr(ctxn) { + ctx = current->perf_event_ctxp[ctxn]; + if (!ctx) + continue; + + perf_event_enable_on_exec(ctx); + } + rcu_read_unlock(); +} + /* * Cross CPU call to read the hardware event */ @@ -5074,21 +5092,9 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event) NULL); } -void perf_event_comm(struct task_struct *task) +void perf_event_comm(struct task_struct *task, bool exec) { struct perf_comm_event comm_event; - struct perf_event_context *ctx; - int ctxn; - - rcu_read_lock(); - for_each_task_context_nr(ctxn) { - ctx = task->perf_event_ctxp[ctxn]; - if (!ctx) - continue; - - perf_event_enable_on_exec(ctx); - } - rcu_read_unlock(); if (!atomic_read(&nr_comm_events)) return; @@ -5100,7 +5106,7 @@ void perf_event_comm(struct task_struct *task) .event_id = { .header = { .type = PERF_RECORD_COMM, - .misc = 0, + .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, /* .size */ }, /* .pid */ @@ -5123,6 +5129,7 @@ struct perf_mmap_event { int maj, min; u64 ino; u64 ino_generation; + u32 prot, flags; struct { struct perf_event_header header; @@ -5164,6 +5171,8 @@ static void perf_event_mmap_output(struct perf_event *event, mmap_event->event_id.header.size += sizeof(mmap_event->min); mmap_event->event_id.header.size += sizeof(mmap_event->ino); mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); + mmap_event->event_id.header.size += sizeof(mmap_event->prot); + mmap_event->event_id.header.size += sizeof(mmap_event->flags); } perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); @@ -5182,6 +5191,8 @@ static void perf_event_mmap_output(struct perf_event *event, perf_output_put(&handle, mmap_event->min); perf_output_put(&handle, mmap_event->ino); perf_output_put(&handle, mmap_event->ino_generation); + perf_output_put(&handle, mmap_event->prot); + perf_output_put(&handle, mmap_event->flags); } __output_copy(&handle, mmap_event->file_name, @@ -5200,6 +5211,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) struct file *file = vma->vm_file; int maj = 0, min = 0; u64 ino = 0, gen = 0; + u32 prot = 0, flags = 0; unsigned int size; char tmp[16]; char *buf = NULL; @@ -5230,6 +5242,28 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) gen = inode->i_generation; maj = MAJOR(dev); min = MINOR(dev); + + if (vma->vm_flags & VM_READ) + prot |= PROT_READ; + if (vma->vm_flags & VM_WRITE) + prot |= PROT_WRITE; + if (vma->vm_flags & VM_EXEC) + prot |= PROT_EXEC; + + if (vma->vm_flags & VM_MAYSHARE) + flags = MAP_SHARED; + else + flags = MAP_PRIVATE; + + if (vma->vm_flags & VM_DENYWRITE) + flags |= MAP_DENYWRITE; + if (vma->vm_flags & VM_MAYEXEC) + flags |= MAP_EXECUTABLE; + if (vma->vm_flags & VM_LOCKED) + flags |= MAP_LOCKED; + if (vma->vm_flags & VM_HUGETLB) + flags |= MAP_HUGETLB; + goto got_name; } else { name = (char *)arch_vma_name(vma); @@ -5270,6 +5304,8 @@ got_name: mmap_event->min = min; mmap_event->ino = ino; mmap_event->ino_generation = gen; + mmap_event->prot = prot; + mmap_event->flags = flags; if (!(vma->vm_flags & VM_EXEC)) mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA; @@ -5310,6 +5346,8 @@ void perf_event_mmap(struct vm_area_struct *vma) /* .min (attr_mmap2 only) */ /* .ino (attr_mmap2 only) */ /* .ino_generation (attr_mmap2 only) */ + /* .prot (attr_mmap2 only) */ + /* .flags (attr_mmap2 only) */ }; perf_event_mmap_event(&mmap_event); @@ -6892,10 +6930,6 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, if (ret) return -EFAULT; - /* disabled for now */ - if (attr->mmap2) - return -EINVAL; - if (attr->__reserved_1) return -EINVAL; @@ -7121,6 +7155,13 @@ SYSCALL_DEFINE5(perf_event_open, } } + if (is_sampling_event(event)) { + if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { + err = -ENOTSUPP; + goto err_alloc; + } + } + account_event(event); /* @@ -7432,7 +7473,7 @@ __perf_event_exit_task(struct perf_event *child_event, static void perf_event_exit_task_context(struct task_struct *child, int ctxn) { - struct perf_event *child_event; + struct perf_event *child_event, *next; struct perf_event_context *child_ctx; unsigned long flags; @@ -7486,7 +7527,7 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn) */ mutex_lock(&child_ctx->mutex); - list_for_each_entry_rcu(child_event, &child_ctx->event_list, event_entry) + list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) __perf_event_exit_task(child_event, child_ctx, child); mutex_unlock(&child_ctx->mutex); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index adcd76a96839..6f3254e8c137 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -36,6 +36,7 @@ #include "../../mm/internal.h" /* munlock_vma_page */ #include <linux/percpu-rwsem.h> #include <linux/task_work.h> +#include <linux/shmem_fs.h> #include <linux/uprobes.h> @@ -127,7 +128,7 @@ struct xol_area { */ static bool valid_vma(struct vm_area_struct *vma, bool is_register) { - vm_flags_t flags = VM_HUGETLB | VM_MAYEXEC | VM_SHARED; + vm_flags_t flags = VM_HUGETLB | VM_MAYEXEC | VM_MAYSHARE; if (is_register) flags |= VM_WRITE; @@ -279,18 +280,13 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t * supported by that architecture then we need to modify is_trap_at_addr and * uprobe_write_opcode accordingly. This would never be a problem for archs * that have fixed length instructions. - */ - -/* + * * uprobe_write_opcode - write the opcode at a given virtual address. * @mm: the probed process address space. * @vaddr: the virtual address to store the opcode. * @opcode: opcode to be written at @vaddr. * - * Called with mm->mmap_sem held (for read and with a reference to - * mm). - * - * For mm @mm, write the opcode at @vaddr. + * Called with mm->mmap_sem held for write. * Return 0 (success) or a negative errno. */ int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr, @@ -310,21 +306,25 @@ retry: if (ret <= 0) goto put_old; + ret = anon_vma_prepare(vma); + if (ret) + goto put_old; + ret = -ENOMEM; new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr); if (!new_page) goto put_old; - __SetPageUptodate(new_page); + if (mem_cgroup_charge_anon(new_page, mm, GFP_KERNEL)) + goto put_new; + __SetPageUptodate(new_page); copy_highpage(new_page, old_page); copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE); - ret = anon_vma_prepare(vma); - if (ret) - goto put_new; - ret = __replace_page(vma, vaddr, old_page, new_page); + if (ret) + mem_cgroup_uncharge_page(new_page); put_new: page_cache_release(new_page); @@ -537,14 +537,15 @@ static int __copy_insn(struct address_space *mapping, struct file *filp, void *insn, int nbytes, loff_t offset) { struct page *page; - - if (!mapping->a_ops->readpage) - return -EIO; /* - * Ensure that the page that has the original instruction is - * populated and in page-cache. + * Ensure that the page that has the original instruction is populated + * and in page-cache. If ->readpage == NULL it must be shmem_mapping(), + * see uprobe_register(). */ - page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp); + if (mapping->a_ops->readpage) + page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp); + else + page = shmem_read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT); if (IS_ERR(page)) return PTR_ERR(page); @@ -845,7 +846,7 @@ static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *u { int err; - if (!consumer_del(uprobe, uc)) /* WARN? */ + if (WARN_ON(!consumer_del(uprobe, uc))) return; err = register_for_each_vma(uprobe, NULL); @@ -880,6 +881,9 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer * if (!uc->handler && !uc->ret_handler) return -EINVAL; + /* copy_insn() uses read_mapping_page() or shmem_read_mapping_page() */ + if (!inode->i_mapping->a_ops->readpage && !shmem_mapping(inode->i_mapping)) + return -EIO; /* Racy, just to catch the obvious mistakes */ if (offset > i_size_read(inode)) return -EINVAL; @@ -923,7 +927,7 @@ int uprobe_apply(struct inode *inode, loff_t offset, int ret = -ENOENT; uprobe = find_uprobe(inode, offset); - if (!uprobe) + if (WARN_ON(!uprobe)) return ret; down_write(&uprobe->register_rwsem); @@ -948,7 +952,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume struct uprobe *uprobe; uprobe = find_uprobe(inode, offset); - if (!uprobe) + if (WARN_ON(!uprobe)) return; down_write(&uprobe->register_rwsem); @@ -1361,6 +1365,16 @@ unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs) return instruction_pointer(regs) - UPROBE_SWBP_INSN_SIZE; } +unsigned long uprobe_get_trap_addr(struct pt_regs *regs) +{ + struct uprobe_task *utask = current->utask; + + if (unlikely(utask && utask->active_uprobe)) + return utask->vaddr; + + return instruction_pointer(regs); +} + /* * Called with no locks held. * Called in context of a exiting or a exec-ing thread. diff --git a/kernel/fork.c b/kernel/fork.c index ea0dd7075543..8f541930ce26 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1487,7 +1487,9 @@ static struct task_struct *copy_process(unsigned long clone_flags, total_forks++; spin_unlock(¤t->sighand->siglock); + syscall_tracepoint_update(p); write_unlock_irq(&tasklist_lock); + proc_fork_connector(p); cgroup_post_fork(p); if (clone_flags & CLONE_THREAD) diff --git a/kernel/gcov/base.c b/kernel/gcov/base.c index f45b75b713c0..b358a802fd18 100644 --- a/kernel/gcov/base.c +++ b/kernel/gcov/base.c @@ -85,6 +85,12 @@ void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters) } EXPORT_SYMBOL(__gcov_merge_ior); +void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters) +{ + /* Unused. */ +} +EXPORT_SYMBOL(__gcov_merge_time_profile); + /** * gcov_enable_events - enable event reporting through gcov_event() * diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c index 2c6e4631c814..826ba9fb5e32 100644 --- a/kernel/gcov/gcc_4_7.c +++ b/kernel/gcov/gcc_4_7.c @@ -18,7 +18,12 @@ #include <linux/vmalloc.h> #include "gcov.h" +#if __GNUC__ == 4 && __GNUC_MINOR__ >= 9 +#define GCOV_COUNTERS 9 +#else #define GCOV_COUNTERS 8 +#endif + #define GCOV_TAG_FUNCTION_LENGTH 3 static struct gcov_info *gcov_info_head; diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 7339e42a85ab..1487a123db5c 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -455,9 +455,9 @@ EXPORT_SYMBOL_GPL(irq_alloc_hwirqs); */ void irq_free_hwirqs(unsigned int from, int cnt) { - int i; + int i, j; - for (i = from; cnt > 0; i++, cnt--) { + for (i = from, j = cnt; j > 0; i++, j--) { irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE); arch_teardown_hwirq(i); } diff --git a/kernel/kexec.c b/kernel/kexec.c index 6748688813d0..369f41a94124 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1617,6 +1617,7 @@ static int __init crash_save_vmcoreinfo_init(void) #ifdef CONFIG_MEMORY_FAILURE VMCOREINFO_NUMBER(PG_hwpoison); #endif + VMCOREINFO_NUMBER(PG_head_mask); VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); arch_crash_save_vmcoreinfo(); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ceeadfcabb76..3214289df5a7 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -86,21 +86,8 @@ static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) return &(kretprobe_table_locks[hash].lock); } -/* - * Normally, functions that we'd want to prohibit kprobes in, are marked - * __kprobes. But, there are cases where such functions already belong to - * a different section (__sched for preempt_schedule) - * - * For such cases, we now have a blacklist - */ -static struct kprobe_blackpoint kprobe_blacklist[] = { - {"preempt_schedule",}, - {"native_get_debugreg",}, - {"irq_entries_start",}, - {"common_interrupt",}, - {"mcount",}, /* mcount can be called from everywhere */ - {NULL} /* Terminator */ -}; +/* Blacklist -- list of struct kprobe_blacklist_entry */ +static LIST_HEAD(kprobe_blacklist); #ifdef __ARCH_WANT_KPROBES_INSN_SLOT /* @@ -151,13 +138,13 @@ struct kprobe_insn_cache kprobe_insn_slots = { .insn_size = MAX_INSN_SIZE, .nr_garbage = 0, }; -static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c); +static int collect_garbage_slots(struct kprobe_insn_cache *c); /** * __get_insn_slot() - Find a slot on an executable page for an instruction. * We allocate an executable page if there's no room on existing ones. */ -kprobe_opcode_t __kprobes *__get_insn_slot(struct kprobe_insn_cache *c) +kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c) { struct kprobe_insn_page *kip; kprobe_opcode_t *slot = NULL; @@ -214,7 +201,7 @@ out: } /* Return 1 if all garbages are collected, otherwise 0. */ -static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) +static int collect_one_slot(struct kprobe_insn_page *kip, int idx) { kip->slot_used[idx] = SLOT_CLEAN; kip->nused--; @@ -235,7 +222,7 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx) return 0; } -static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c) +static int collect_garbage_slots(struct kprobe_insn_cache *c) { struct kprobe_insn_page *kip, *next; @@ -257,8 +244,8 @@ static int __kprobes collect_garbage_slots(struct kprobe_insn_cache *c) return 0; } -void __kprobes __free_insn_slot(struct kprobe_insn_cache *c, - kprobe_opcode_t *slot, int dirty) +void __free_insn_slot(struct kprobe_insn_cache *c, + kprobe_opcode_t *slot, int dirty) { struct kprobe_insn_page *kip; @@ -314,7 +301,7 @@ static inline void reset_kprobe_instance(void) * OR * - with preemption disabled - from arch/xxx/kernel/kprobes.c */ -struct kprobe __kprobes *get_kprobe(void *addr) +struct kprobe *get_kprobe(void *addr) { struct hlist_head *head; struct kprobe *p; @@ -327,8 +314,9 @@ struct kprobe __kprobes *get_kprobe(void *addr) return NULL; } +NOKPROBE_SYMBOL(get_kprobe); -static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); +static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); /* Return true if the kprobe is an aggregator */ static inline int kprobe_aggrprobe(struct kprobe *p) @@ -360,7 +348,7 @@ static bool kprobes_allow_optimization; * Call all pre_handler on the list, but ignores its return value. * This must be called from arch-dep optimized caller. */ -void __kprobes opt_pre_handler(struct kprobe *p, struct pt_regs *regs) +void opt_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe *kp; @@ -372,9 +360,10 @@ void __kprobes opt_pre_handler(struct kprobe *p, struct pt_regs *regs) reset_kprobe_instance(); } } +NOKPROBE_SYMBOL(opt_pre_handler); /* Free optimized instructions and optimized_kprobe */ -static __kprobes void free_aggr_kprobe(struct kprobe *p) +static void free_aggr_kprobe(struct kprobe *p) { struct optimized_kprobe *op; @@ -412,7 +401,7 @@ static inline int kprobe_disarmed(struct kprobe *p) } /* Return true(!0) if the probe is queued on (un)optimizing lists */ -static int __kprobes kprobe_queued(struct kprobe *p) +static int kprobe_queued(struct kprobe *p) { struct optimized_kprobe *op; @@ -428,7 +417,7 @@ static int __kprobes kprobe_queued(struct kprobe *p) * Return an optimized kprobe whose optimizing code replaces * instructions including addr (exclude breakpoint). */ -static struct kprobe *__kprobes get_optimized_kprobe(unsigned long addr) +static struct kprobe *get_optimized_kprobe(unsigned long addr) { int i; struct kprobe *p = NULL; @@ -460,7 +449,7 @@ static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); * Optimize (replace a breakpoint with a jump) kprobes listed on * optimizing_list. */ -static __kprobes void do_optimize_kprobes(void) +static void do_optimize_kprobes(void) { /* Optimization never be done when disarmed */ if (kprobes_all_disarmed || !kprobes_allow_optimization || @@ -488,7 +477,7 @@ static __kprobes void do_optimize_kprobes(void) * Unoptimize (replace a jump with a breakpoint and remove the breakpoint * if need) kprobes listed on unoptimizing_list. */ -static __kprobes void do_unoptimize_kprobes(void) +static void do_unoptimize_kprobes(void) { struct optimized_kprobe *op, *tmp; @@ -520,7 +509,7 @@ static __kprobes void do_unoptimize_kprobes(void) } /* Reclaim all kprobes on the free_list */ -static __kprobes void do_free_cleaned_kprobes(void) +static void do_free_cleaned_kprobes(void) { struct optimized_kprobe *op, *tmp; @@ -532,13 +521,13 @@ static __kprobes void do_free_cleaned_kprobes(void) } /* Start optimizer after OPTIMIZE_DELAY passed */ -static __kprobes void kick_kprobe_optimizer(void) +static void kick_kprobe_optimizer(void) { schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); } /* Kprobe jump optimizer */ -static __kprobes void kprobe_optimizer(struct work_struct *work) +static void kprobe_optimizer(struct work_struct *work) { mutex_lock(&kprobe_mutex); /* Lock modules while optimizing kprobes */ @@ -574,7 +563,7 @@ static __kprobes void kprobe_optimizer(struct work_struct *work) } /* Wait for completing optimization and unoptimization */ -static __kprobes void wait_for_kprobe_optimizer(void) +static void wait_for_kprobe_optimizer(void) { mutex_lock(&kprobe_mutex); @@ -593,7 +582,7 @@ static __kprobes void wait_for_kprobe_optimizer(void) } /* Optimize kprobe if p is ready to be optimized */ -static __kprobes void optimize_kprobe(struct kprobe *p) +static void optimize_kprobe(struct kprobe *p) { struct optimized_kprobe *op; @@ -627,7 +616,7 @@ static __kprobes void optimize_kprobe(struct kprobe *p) } /* Short cut to direct unoptimizing */ -static __kprobes void force_unoptimize_kprobe(struct optimized_kprobe *op) +static void force_unoptimize_kprobe(struct optimized_kprobe *op) { get_online_cpus(); arch_unoptimize_kprobe(op); @@ -637,7 +626,7 @@ static __kprobes void force_unoptimize_kprobe(struct optimized_kprobe *op) } /* Unoptimize a kprobe if p is optimized */ -static __kprobes void unoptimize_kprobe(struct kprobe *p, bool force) +static void unoptimize_kprobe(struct kprobe *p, bool force) { struct optimized_kprobe *op; @@ -697,7 +686,7 @@ static void reuse_unused_kprobe(struct kprobe *ap) } /* Remove optimized instructions */ -static void __kprobes kill_optimized_kprobe(struct kprobe *p) +static void kill_optimized_kprobe(struct kprobe *p) { struct optimized_kprobe *op; @@ -723,7 +712,7 @@ static void __kprobes kill_optimized_kprobe(struct kprobe *p) } /* Try to prepare optimized instructions */ -static __kprobes void prepare_optimized_kprobe(struct kprobe *p) +static void prepare_optimized_kprobe(struct kprobe *p) { struct optimized_kprobe *op; @@ -732,7 +721,7 @@ static __kprobes void prepare_optimized_kprobe(struct kprobe *p) } /* Allocate new optimized_kprobe and try to prepare optimized instructions */ -static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) +static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) { struct optimized_kprobe *op; @@ -747,13 +736,13 @@ static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) return &op->kp; } -static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); +static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); /* * Prepare an optimized_kprobe and optimize it * NOTE: p must be a normal registered kprobe */ -static __kprobes void try_to_optimize_kprobe(struct kprobe *p) +static void try_to_optimize_kprobe(struct kprobe *p) { struct kprobe *ap; struct optimized_kprobe *op; @@ -787,7 +776,7 @@ out: } #ifdef CONFIG_SYSCTL -static void __kprobes optimize_all_kprobes(void) +static void optimize_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; @@ -810,7 +799,7 @@ out: mutex_unlock(&kprobe_mutex); } -static void __kprobes unoptimize_all_kprobes(void) +static void unoptimize_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; @@ -861,7 +850,7 @@ int proc_kprobes_optimization_handler(struct ctl_table *table, int write, #endif /* CONFIG_SYSCTL */ /* Put a breakpoint for a probe. Must be called with text_mutex locked */ -static void __kprobes __arm_kprobe(struct kprobe *p) +static void __arm_kprobe(struct kprobe *p) { struct kprobe *_p; @@ -876,7 +865,7 @@ static void __kprobes __arm_kprobe(struct kprobe *p) } /* Remove the breakpoint of a probe. Must be called with text_mutex locked */ -static void __kprobes __disarm_kprobe(struct kprobe *p, bool reopt) +static void __disarm_kprobe(struct kprobe *p, bool reopt) { struct kprobe *_p; @@ -911,13 +900,13 @@ static void reuse_unused_kprobe(struct kprobe *ap) BUG_ON(kprobe_unused(ap)); } -static __kprobes void free_aggr_kprobe(struct kprobe *p) +static void free_aggr_kprobe(struct kprobe *p) { arch_remove_kprobe(p); kfree(p); } -static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) +static struct kprobe *alloc_aggr_kprobe(struct kprobe *p) { return kzalloc(sizeof(struct kprobe), GFP_KERNEL); } @@ -931,7 +920,7 @@ static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { static int kprobe_ftrace_enabled; /* Must ensure p->addr is really on ftrace */ -static int __kprobes prepare_kprobe(struct kprobe *p) +static int prepare_kprobe(struct kprobe *p) { if (!kprobe_ftrace(p)) return arch_prepare_kprobe(p); @@ -940,7 +929,7 @@ static int __kprobes prepare_kprobe(struct kprobe *p) } /* Caller must lock kprobe_mutex */ -static void __kprobes arm_kprobe_ftrace(struct kprobe *p) +static void arm_kprobe_ftrace(struct kprobe *p) { int ret; @@ -955,7 +944,7 @@ static void __kprobes arm_kprobe_ftrace(struct kprobe *p) } /* Caller must lock kprobe_mutex */ -static void __kprobes disarm_kprobe_ftrace(struct kprobe *p) +static void disarm_kprobe_ftrace(struct kprobe *p) { int ret; @@ -975,7 +964,7 @@ static void __kprobes disarm_kprobe_ftrace(struct kprobe *p) #endif /* Arm a kprobe with text_mutex */ -static void __kprobes arm_kprobe(struct kprobe *kp) +static void arm_kprobe(struct kprobe *kp) { if (unlikely(kprobe_ftrace(kp))) { arm_kprobe_ftrace(kp); @@ -992,7 +981,7 @@ static void __kprobes arm_kprobe(struct kprobe *kp) } /* Disarm a kprobe with text_mutex */ -static void __kprobes disarm_kprobe(struct kprobe *kp, bool reopt) +static void disarm_kprobe(struct kprobe *kp, bool reopt) { if (unlikely(kprobe_ftrace(kp))) { disarm_kprobe_ftrace(kp); @@ -1008,7 +997,7 @@ static void __kprobes disarm_kprobe(struct kprobe *kp, bool reopt) * Aggregate handlers for multiple kprobes support - these handlers * take care of invoking the individual kprobe handlers on p->list */ -static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) +static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe *kp; @@ -1022,9 +1011,10 @@ static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs) } return 0; } +NOKPROBE_SYMBOL(aggr_pre_handler); -static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, - unsigned long flags) +static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs, + unsigned long flags) { struct kprobe *kp; @@ -1036,9 +1026,10 @@ static void __kprobes aggr_post_handler(struct kprobe *p, struct pt_regs *regs, } } } +NOKPROBE_SYMBOL(aggr_post_handler); -static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, - int trapnr) +static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, + int trapnr) { struct kprobe *cur = __this_cpu_read(kprobe_instance); @@ -1052,8 +1043,9 @@ static int __kprobes aggr_fault_handler(struct kprobe *p, struct pt_regs *regs, } return 0; } +NOKPROBE_SYMBOL(aggr_fault_handler); -static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) +static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe *cur = __this_cpu_read(kprobe_instance); int ret = 0; @@ -1065,9 +1057,10 @@ static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) reset_kprobe_instance(); return ret; } +NOKPROBE_SYMBOL(aggr_break_handler); /* Walks the list and increments nmissed count for multiprobe case */ -void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) +void kprobes_inc_nmissed_count(struct kprobe *p) { struct kprobe *kp; if (!kprobe_aggrprobe(p)) { @@ -1078,9 +1071,10 @@ void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) } return; } +NOKPROBE_SYMBOL(kprobes_inc_nmissed_count); -void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, - struct hlist_head *head) +void recycle_rp_inst(struct kretprobe_instance *ri, + struct hlist_head *head) { struct kretprobe *rp = ri->rp; @@ -1095,8 +1089,9 @@ void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, /* Unregistering */ hlist_add_head(&ri->hlist, head); } +NOKPROBE_SYMBOL(recycle_rp_inst); -void __kprobes kretprobe_hash_lock(struct task_struct *tsk, +void kretprobe_hash_lock(struct task_struct *tsk, struct hlist_head **head, unsigned long *flags) __acquires(hlist_lock) { @@ -1107,17 +1102,19 @@ __acquires(hlist_lock) hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_lock_irqsave(hlist_lock, *flags); } +NOKPROBE_SYMBOL(kretprobe_hash_lock); -static void __kprobes kretprobe_table_lock(unsigned long hash, - unsigned long *flags) +static void kretprobe_table_lock(unsigned long hash, + unsigned long *flags) __acquires(hlist_lock) { raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_lock_irqsave(hlist_lock, *flags); } +NOKPROBE_SYMBOL(kretprobe_table_lock); -void __kprobes kretprobe_hash_unlock(struct task_struct *tsk, - unsigned long *flags) +void kretprobe_hash_unlock(struct task_struct *tsk, + unsigned long *flags) __releases(hlist_lock) { unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS); @@ -1126,14 +1123,16 @@ __releases(hlist_lock) hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_unlock_irqrestore(hlist_lock, *flags); } +NOKPROBE_SYMBOL(kretprobe_hash_unlock); -static void __kprobes kretprobe_table_unlock(unsigned long hash, - unsigned long *flags) +static void kretprobe_table_unlock(unsigned long hash, + unsigned long *flags) __releases(hlist_lock) { raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash); raw_spin_unlock_irqrestore(hlist_lock, *flags); } +NOKPROBE_SYMBOL(kretprobe_table_unlock); /* * This function is called from finish_task_switch when task tk becomes dead, @@ -1141,7 +1140,7 @@ __releases(hlist_lock) * with this task. These left over instances represent probed functions * that have been called but will never return. */ -void __kprobes kprobe_flush_task(struct task_struct *tk) +void kprobe_flush_task(struct task_struct *tk) { struct kretprobe_instance *ri; struct hlist_head *head, empty_rp; @@ -1166,6 +1165,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk) kfree(ri); } } +NOKPROBE_SYMBOL(kprobe_flush_task); static inline void free_rp_inst(struct kretprobe *rp) { @@ -1178,7 +1178,7 @@ static inline void free_rp_inst(struct kretprobe *rp) } } -static void __kprobes cleanup_rp_inst(struct kretprobe *rp) +static void cleanup_rp_inst(struct kretprobe *rp) { unsigned long flags, hash; struct kretprobe_instance *ri; @@ -1197,12 +1197,13 @@ static void __kprobes cleanup_rp_inst(struct kretprobe *rp) } free_rp_inst(rp); } +NOKPROBE_SYMBOL(cleanup_rp_inst); /* * Add the new probe to ap->list. Fail if this is the * second jprobe at the address - two jprobes can't coexist */ -static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) +static int add_new_kprobe(struct kprobe *ap, struct kprobe *p) { BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); @@ -1226,7 +1227,7 @@ static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) * Fill in the required fields of the "manager kprobe". Replace the * earlier kprobe in the hlist with the manager kprobe */ -static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) +static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) { /* Copy p's insn slot to ap */ copy_kprobe(p, ap); @@ -1252,8 +1253,7 @@ static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) * This is the second or subsequent kprobe at the address - handle * the intricacies */ -static int __kprobes register_aggr_kprobe(struct kprobe *orig_p, - struct kprobe *p) +static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) { int ret = 0; struct kprobe *ap = orig_p; @@ -1324,25 +1324,29 @@ out: return ret; } -static int __kprobes in_kprobes_functions(unsigned long addr) +bool __weak arch_within_kprobe_blacklist(unsigned long addr) { - struct kprobe_blackpoint *kb; + /* The __kprobes marked functions and entry code must not be probed */ + return addr >= (unsigned long)__kprobes_text_start && + addr < (unsigned long)__kprobes_text_end; +} - if (addr >= (unsigned long)__kprobes_text_start && - addr < (unsigned long)__kprobes_text_end) - return -EINVAL; +static bool within_kprobe_blacklist(unsigned long addr) +{ + struct kprobe_blacklist_entry *ent; + + if (arch_within_kprobe_blacklist(addr)) + return true; /* * If there exists a kprobe_blacklist, verify and * fail any probe registration in the prohibited area */ - for (kb = kprobe_blacklist; kb->name != NULL; kb++) { - if (kb->start_addr) { - if (addr >= kb->start_addr && - addr < (kb->start_addr + kb->range)) - return -EINVAL; - } + list_for_each_entry(ent, &kprobe_blacklist, list) { + if (addr >= ent->start_addr && addr < ent->end_addr) + return true; } - return 0; + + return false; } /* @@ -1351,7 +1355,7 @@ static int __kprobes in_kprobes_functions(unsigned long addr) * This returns encoded errors if it fails to look up symbol or invalid * combination of parameters. */ -static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p) +static kprobe_opcode_t *kprobe_addr(struct kprobe *p) { kprobe_opcode_t *addr = p->addr; @@ -1374,7 +1378,7 @@ invalid: } /* Check passed kprobe is valid and return kprobe in kprobe_table. */ -static struct kprobe * __kprobes __get_valid_kprobe(struct kprobe *p) +static struct kprobe *__get_valid_kprobe(struct kprobe *p) { struct kprobe *ap, *list_p; @@ -1406,8 +1410,8 @@ static inline int check_kprobe_rereg(struct kprobe *p) return ret; } -static __kprobes int check_kprobe_address_safe(struct kprobe *p, - struct module **probed_mod) +static int check_kprobe_address_safe(struct kprobe *p, + struct module **probed_mod) { int ret = 0; unsigned long ftrace_addr; @@ -1433,7 +1437,7 @@ static __kprobes int check_kprobe_address_safe(struct kprobe *p, /* Ensure it is not in reserved area nor out of text */ if (!kernel_text_address((unsigned long) p->addr) || - in_kprobes_functions((unsigned long) p->addr) || + within_kprobe_blacklist((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr)) { ret = -EINVAL; goto out; @@ -1469,7 +1473,7 @@ out: return ret; } -int __kprobes register_kprobe(struct kprobe *p) +int register_kprobe(struct kprobe *p) { int ret; struct kprobe *old_p; @@ -1531,7 +1535,7 @@ out: EXPORT_SYMBOL_GPL(register_kprobe); /* Check if all probes on the aggrprobe are disabled */ -static int __kprobes aggr_kprobe_disabled(struct kprobe *ap) +static int aggr_kprobe_disabled(struct kprobe *ap) { struct kprobe *kp; @@ -1547,7 +1551,7 @@ static int __kprobes aggr_kprobe_disabled(struct kprobe *ap) } /* Disable one kprobe: Make sure called under kprobe_mutex is locked */ -static struct kprobe *__kprobes __disable_kprobe(struct kprobe *p) +static struct kprobe *__disable_kprobe(struct kprobe *p) { struct kprobe *orig_p; @@ -1574,7 +1578,7 @@ static struct kprobe *__kprobes __disable_kprobe(struct kprobe *p) /* * Unregister a kprobe without a scheduler synchronization. */ -static int __kprobes __unregister_kprobe_top(struct kprobe *p) +static int __unregister_kprobe_top(struct kprobe *p) { struct kprobe *ap, *list_p; @@ -1631,7 +1635,7 @@ disarmed: return 0; } -static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) +static void __unregister_kprobe_bottom(struct kprobe *p) { struct kprobe *ap; @@ -1647,7 +1651,7 @@ static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) /* Otherwise, do nothing. */ } -int __kprobes register_kprobes(struct kprobe **kps, int num) +int register_kprobes(struct kprobe **kps, int num) { int i, ret = 0; @@ -1665,13 +1669,13 @@ int __kprobes register_kprobes(struct kprobe **kps, int num) } EXPORT_SYMBOL_GPL(register_kprobes); -void __kprobes unregister_kprobe(struct kprobe *p) +void unregister_kprobe(struct kprobe *p) { unregister_kprobes(&p, 1); } EXPORT_SYMBOL_GPL(unregister_kprobe); -void __kprobes unregister_kprobes(struct kprobe **kps, int num) +void unregister_kprobes(struct kprobe **kps, int num) { int i; @@ -1700,7 +1704,7 @@ unsigned long __weak arch_deref_entry_point(void *entry) return (unsigned long)entry; } -int __kprobes register_jprobes(struct jprobe **jps, int num) +int register_jprobes(struct jprobe **jps, int num) { struct jprobe *jp; int ret = 0, i; @@ -1731,19 +1735,19 @@ int __kprobes register_jprobes(struct jprobe **jps, int num) } EXPORT_SYMBOL_GPL(register_jprobes); -int __kprobes register_jprobe(struct jprobe *jp) +int register_jprobe(struct jprobe *jp) { return register_jprobes(&jp, 1); } EXPORT_SYMBOL_GPL(register_jprobe); -void __kprobes unregister_jprobe(struct jprobe *jp) +void unregister_jprobe(struct jprobe *jp) { unregister_jprobes(&jp, 1); } EXPORT_SYMBOL_GPL(unregister_jprobe); -void __kprobes unregister_jprobes(struct jprobe **jps, int num) +void unregister_jprobes(struct jprobe **jps, int num) { int i; @@ -1768,8 +1772,7 @@ EXPORT_SYMBOL_GPL(unregister_jprobes); * This kprobe pre_handler is registered with every kretprobe. When probe * hits it will set up the return probe. */ -static int __kprobes pre_handler_kretprobe(struct kprobe *p, - struct pt_regs *regs) +static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) { struct kretprobe *rp = container_of(p, struct kretprobe, kp); unsigned long hash, flags = 0; @@ -1807,8 +1810,9 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, } return 0; } +NOKPROBE_SYMBOL(pre_handler_kretprobe); -int __kprobes register_kretprobe(struct kretprobe *rp) +int register_kretprobe(struct kretprobe *rp) { int ret = 0; struct kretprobe_instance *inst; @@ -1861,7 +1865,7 @@ int __kprobes register_kretprobe(struct kretprobe *rp) } EXPORT_SYMBOL_GPL(register_kretprobe); -int __kprobes register_kretprobes(struct kretprobe **rps, int num) +int register_kretprobes(struct kretprobe **rps, int num) { int ret = 0, i; @@ -1879,13 +1883,13 @@ int __kprobes register_kretprobes(struct kretprobe **rps, int num) } EXPORT_SYMBOL_GPL(register_kretprobes); -void __kprobes unregister_kretprobe(struct kretprobe *rp) +void unregister_kretprobe(struct kretprobe *rp) { unregister_kretprobes(&rp, 1); } EXPORT_SYMBOL_GPL(unregister_kretprobe); -void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) +void unregister_kretprobes(struct kretprobe **rps, int num) { int i; @@ -1908,38 +1912,38 @@ void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) EXPORT_SYMBOL_GPL(unregister_kretprobes); #else /* CONFIG_KRETPROBES */ -int __kprobes register_kretprobe(struct kretprobe *rp) +int register_kretprobe(struct kretprobe *rp) { return -ENOSYS; } EXPORT_SYMBOL_GPL(register_kretprobe); -int __kprobes register_kretprobes(struct kretprobe **rps, int num) +int register_kretprobes(struct kretprobe **rps, int num) { return -ENOSYS; } EXPORT_SYMBOL_GPL(register_kretprobes); -void __kprobes unregister_kretprobe(struct kretprobe *rp) +void unregister_kretprobe(struct kretprobe *rp) { } EXPORT_SYMBOL_GPL(unregister_kretprobe); -void __kprobes unregister_kretprobes(struct kretprobe **rps, int num) +void unregister_kretprobes(struct kretprobe **rps, int num) { } EXPORT_SYMBOL_GPL(unregister_kretprobes); -static int __kprobes pre_handler_kretprobe(struct kprobe *p, - struct pt_regs *regs) +static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) { return 0; } +NOKPROBE_SYMBOL(pre_handler_kretprobe); #endif /* CONFIG_KRETPROBES */ /* Set the kprobe gone and remove its instruction buffer. */ -static void __kprobes kill_kprobe(struct kprobe *p) +static void kill_kprobe(struct kprobe *p) { struct kprobe *kp; @@ -1963,7 +1967,7 @@ static void __kprobes kill_kprobe(struct kprobe *p) } /* Disable one kprobe */ -int __kprobes disable_kprobe(struct kprobe *kp) +int disable_kprobe(struct kprobe *kp) { int ret = 0; @@ -1979,7 +1983,7 @@ int __kprobes disable_kprobe(struct kprobe *kp) EXPORT_SYMBOL_GPL(disable_kprobe); /* Enable one kprobe */ -int __kprobes enable_kprobe(struct kprobe *kp) +int enable_kprobe(struct kprobe *kp) { int ret = 0; struct kprobe *p; @@ -2012,16 +2016,49 @@ out: } EXPORT_SYMBOL_GPL(enable_kprobe); -void __kprobes dump_kprobe(struct kprobe *kp) +void dump_kprobe(struct kprobe *kp) { printk(KERN_WARNING "Dumping kprobe:\n"); printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n", kp->symbol_name, kp->addr, kp->offset); } +NOKPROBE_SYMBOL(dump_kprobe); + +/* + * Lookup and populate the kprobe_blacklist. + * + * Unlike the kretprobe blacklist, we'll need to determine + * the range of addresses that belong to the said functions, + * since a kprobe need not necessarily be at the beginning + * of a function. + */ +static int __init populate_kprobe_blacklist(unsigned long *start, + unsigned long *end) +{ + unsigned long *iter; + struct kprobe_blacklist_entry *ent; + unsigned long offset = 0, size = 0; + + for (iter = start; iter < end; iter++) { + if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) { + pr_err("Failed to find blacklist %p\n", (void *)*iter); + continue; + } + + ent = kmalloc(sizeof(*ent), GFP_KERNEL); + if (!ent) + return -ENOMEM; + ent->start_addr = *iter; + ent->end_addr = *iter + size; + INIT_LIST_HEAD(&ent->list); + list_add_tail(&ent->list, &kprobe_blacklist); + } + return 0; +} /* Module notifier call back, checking kprobes on the module */ -static int __kprobes kprobes_module_callback(struct notifier_block *nb, - unsigned long val, void *data) +static int kprobes_module_callback(struct notifier_block *nb, + unsigned long val, void *data) { struct module *mod = data; struct hlist_head *head; @@ -2062,14 +2099,13 @@ static struct notifier_block kprobe_module_nb = { .priority = 0 }; +/* Markers of _kprobe_blacklist section */ +extern unsigned long __start_kprobe_blacklist[]; +extern unsigned long __stop_kprobe_blacklist[]; + static int __init init_kprobes(void) { int i, err = 0; - unsigned long offset = 0, size = 0; - char *modname, namebuf[KSYM_NAME_LEN]; - const char *symbol_name; - void *addr; - struct kprobe_blackpoint *kb; /* FIXME allocate the probe table, currently defined statically */ /* initialize all list heads */ @@ -2079,26 +2115,11 @@ static int __init init_kprobes(void) raw_spin_lock_init(&(kretprobe_table_locks[i].lock)); } - /* - * Lookup and populate the kprobe_blacklist. - * - * Unlike the kretprobe blacklist, we'll need to determine - * the range of addresses that belong to the said functions, - * since a kprobe need not necessarily be at the beginning - * of a function. - */ - for (kb = kprobe_blacklist; kb->name != NULL; kb++) { - kprobe_lookup_name(kb->name, addr); - if (!addr) - continue; - - kb->start_addr = (unsigned long)addr; - symbol_name = kallsyms_lookup(kb->start_addr, - &size, &offset, &modname, namebuf); - if (!symbol_name) - kb->range = 0; - else - kb->range = size; + err = populate_kprobe_blacklist(__start_kprobe_blacklist, + __stop_kprobe_blacklist); + if (err) { + pr_err("kprobes: failed to populate blacklist: %d\n", err); + pr_err("Please take care of using kprobes.\n"); } if (kretprobe_blacklist_size) { @@ -2138,7 +2159,7 @@ static int __init init_kprobes(void) } #ifdef CONFIG_DEBUG_FS -static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, +static void report_probe(struct seq_file *pi, struct kprobe *p, const char *sym, int offset, char *modname, struct kprobe *pp) { char *kprobe_type; @@ -2167,12 +2188,12 @@ static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, (kprobe_ftrace(pp) ? "[FTRACE]" : "")); } -static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) +static void *kprobe_seq_start(struct seq_file *f, loff_t *pos) { return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL; } -static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) +static void *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) { (*pos)++; if (*pos >= KPROBE_TABLE_SIZE) @@ -2180,12 +2201,12 @@ static void __kprobes *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos) return pos; } -static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v) +static void kprobe_seq_stop(struct seq_file *f, void *v) { /* Nothing to do */ } -static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) +static int show_kprobe_addr(struct seq_file *pi, void *v) { struct hlist_head *head; struct kprobe *p, *kp; @@ -2216,7 +2237,7 @@ static const struct seq_operations kprobes_seq_ops = { .show = show_kprobe_addr }; -static int __kprobes kprobes_open(struct inode *inode, struct file *filp) +static int kprobes_open(struct inode *inode, struct file *filp) { return seq_open(filp, &kprobes_seq_ops); } @@ -2228,7 +2249,47 @@ static const struct file_operations debugfs_kprobes_operations = { .release = seq_release, }; -static void __kprobes arm_all_kprobes(void) +/* kprobes/blacklist -- shows which functions can not be probed */ +static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) +{ + return seq_list_start(&kprobe_blacklist, *pos); +} + +static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + return seq_list_next(v, &kprobe_blacklist, pos); +} + +static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) +{ + struct kprobe_blacklist_entry *ent = + list_entry(v, struct kprobe_blacklist_entry, list); + + seq_printf(m, "0x%p-0x%p\t%ps\n", (void *)ent->start_addr, + (void *)ent->end_addr, (void *)ent->start_addr); + return 0; +} + +static const struct seq_operations kprobe_blacklist_seq_ops = { + .start = kprobe_blacklist_seq_start, + .next = kprobe_blacklist_seq_next, + .stop = kprobe_seq_stop, /* Reuse void function */ + .show = kprobe_blacklist_seq_show, +}; + +static int kprobe_blacklist_open(struct inode *inode, struct file *filp) +{ + return seq_open(filp, &kprobe_blacklist_seq_ops); +} + +static const struct file_operations debugfs_kprobe_blacklist_ops = { + .open = kprobe_blacklist_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static void arm_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; @@ -2256,7 +2317,7 @@ already_enabled: return; } -static void __kprobes disarm_all_kprobes(void) +static void disarm_all_kprobes(void) { struct hlist_head *head; struct kprobe *p; @@ -2340,7 +2401,7 @@ static const struct file_operations fops_kp = { .llseek = default_llseek, }; -static int __kprobes debugfs_kprobe_init(void) +static int __init debugfs_kprobe_init(void) { struct dentry *dir, *file; unsigned int value = 1; @@ -2351,19 +2412,24 @@ static int __kprobes debugfs_kprobe_init(void) file = debugfs_create_file("list", 0444, dir, NULL, &debugfs_kprobes_operations); - if (!file) { - debugfs_remove(dir); - return -ENOMEM; - } + if (!file) + goto error; file = debugfs_create_file("enabled", 0600, dir, &value, &fops_kp); - if (!file) { - debugfs_remove(dir); - return -ENOMEM; - } + if (!file) + goto error; + + file = debugfs_create_file("blacklist", 0444, dir, NULL, + &debugfs_kprobe_blacklist_ops); + if (!file) + goto error; return 0; + +error: + debugfs_remove(dir); + return -ENOMEM; } late_initcall(debugfs_kprobe_init); diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index b8bdcd4785b7..8541bfdfd232 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile @@ -24,4 +24,5 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o obj-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o +obj-$(CONFIG_QUEUE_RWLOCK) += qrwlock.o obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c new file mode 100644 index 000000000000..fb5b8ac411a5 --- /dev/null +++ b/kernel/locking/qrwlock.c @@ -0,0 +1,133 @@ +/* + * Queue read/write lock + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * (C) Copyright 2013-2014 Hewlett-Packard Development Company, L.P. + * + * Authors: Waiman Long <waiman.long@hp.com> + */ +#include <linux/smp.h> +#include <linux/bug.h> +#include <linux/cpumask.h> +#include <linux/percpu.h> +#include <linux/hardirq.h> +#include <linux/mutex.h> +#include <asm/qrwlock.h> + +/** + * rspin_until_writer_unlock - inc reader count & spin until writer is gone + * @lock : Pointer to queue rwlock structure + * @writer: Current queue rwlock writer status byte + * + * In interrupt context or at the head of the queue, the reader will just + * increment the reader count & wait until the writer releases the lock. + */ +static __always_inline void +rspin_until_writer_unlock(struct qrwlock *lock, u32 cnts) +{ + while ((cnts & _QW_WMASK) == _QW_LOCKED) { + arch_mutex_cpu_relax(); + cnts = smp_load_acquire((u32 *)&lock->cnts); + } +} + +/** + * queue_read_lock_slowpath - acquire read lock of a queue rwlock + * @lock: Pointer to queue rwlock structure + */ +void queue_read_lock_slowpath(struct qrwlock *lock) +{ + u32 cnts; + + /* + * Readers come here when they cannot get the lock without waiting + */ + if (unlikely(in_interrupt())) { + /* + * Readers in interrupt context will spin until the lock is + * available without waiting in the queue. + */ + cnts = smp_load_acquire((u32 *)&lock->cnts); + rspin_until_writer_unlock(lock, cnts); + return; + } + atomic_sub(_QR_BIAS, &lock->cnts); + + /* + * Put the reader into the wait queue + */ + arch_spin_lock(&lock->lock); + + /* + * At the head of the wait queue now, wait until the writer state + * goes to 0 and then try to increment the reader count and get + * the lock. It is possible that an incoming writer may steal the + * lock in the interim, so it is necessary to check the writer byte + * to make sure that the write lock isn't taken. + */ + while (atomic_read(&lock->cnts) & _QW_WMASK) + arch_mutex_cpu_relax(); + + cnts = atomic_add_return(_QR_BIAS, &lock->cnts) - _QR_BIAS; + rspin_until_writer_unlock(lock, cnts); + + /* + * Signal the next one in queue to become queue head + */ + arch_spin_unlock(&lock->lock); +} +EXPORT_SYMBOL(queue_read_lock_slowpath); + +/** + * queue_write_lock_slowpath - acquire write lock of a queue rwlock + * @lock : Pointer to queue rwlock structure + */ +void queue_write_lock_slowpath(struct qrwlock *lock) +{ + u32 cnts; + + /* Put the writer into the wait queue */ + arch_spin_lock(&lock->lock); + + /* Try to acquire the lock directly if no reader is present */ + if (!atomic_read(&lock->cnts) && + (atomic_cmpxchg(&lock->cnts, 0, _QW_LOCKED) == 0)) + goto unlock; + + /* + * Set the waiting flag to notify readers that a writer is pending, + * or wait for a previous writer to go away. + */ + for (;;) { + cnts = atomic_read(&lock->cnts); + if (!(cnts & _QW_WMASK) && + (atomic_cmpxchg(&lock->cnts, cnts, + cnts | _QW_WAITING) == cnts)) + break; + + arch_mutex_cpu_relax(); + } + + /* When no more readers, set the locked flag */ + for (;;) { + cnts = atomic_read(&lock->cnts); + if ((cnts == _QW_WAITING) && + (atomic_cmpxchg(&lock->cnts, _QW_WAITING, + _QW_LOCKED) == _QW_WAITING)) + break; + + arch_mutex_cpu_relax(); + } +unlock: + arch_spin_unlock(&lock->lock); +} +EXPORT_SYMBOL(queue_write_lock_slowpath); diff --git a/kernel/locking/rtmutex-debug.h b/kernel/locking/rtmutex-debug.h index 14193d596d78..ab29b6a22669 100644 --- a/kernel/locking/rtmutex-debug.h +++ b/kernel/locking/rtmutex-debug.h @@ -31,3 +31,8 @@ static inline int debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter, { return (waiter != NULL); } + +static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w) +{ + debug_rt_mutex_print_deadlock(w); +} diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index a620d4d08ca6..fc605941b9b8 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -83,6 +83,47 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock) owner = *p; } while (cmpxchg(p, owner, owner | RT_MUTEX_HAS_WAITERS) != owner); } + +/* + * Safe fastpath aware unlock: + * 1) Clear the waiters bit + * 2) Drop lock->wait_lock + * 3) Try to unlock the lock with cmpxchg + */ +static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock) + __releases(lock->wait_lock) +{ + struct task_struct *owner = rt_mutex_owner(lock); + + clear_rt_mutex_waiters(lock); + raw_spin_unlock(&lock->wait_lock); + /* + * If a new waiter comes in between the unlock and the cmpxchg + * we have two situations: + * + * unlock(wait_lock); + * lock(wait_lock); + * cmpxchg(p, owner, 0) == owner + * mark_rt_mutex_waiters(lock); + * acquire(lock); + * or: + * + * unlock(wait_lock); + * lock(wait_lock); + * mark_rt_mutex_waiters(lock); + * + * cmpxchg(p, owner, 0) != owner + * enqueue_waiter(); + * unlock(wait_lock); + * lock(wait_lock); + * wake waiter(); + * unlock(wait_lock); + * lock(wait_lock); + * acquire(lock); + */ + return rt_mutex_cmpxchg(lock, owner, NULL); +} + #else # define rt_mutex_cmpxchg(l,c,n) (0) static inline void mark_rt_mutex_waiters(struct rt_mutex *lock) @@ -90,6 +131,17 @@ static inline void mark_rt_mutex_waiters(struct rt_mutex *lock) lock->owner = (struct task_struct *) ((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS); } + +/* + * Simple slow path only version: lock->owner is protected by lock->wait_lock. + */ +static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock) + __releases(lock->wait_lock) +{ + lock->owner = NULL; + raw_spin_unlock(&lock->wait_lock); + return true; +} #endif static inline int @@ -260,27 +312,36 @@ static void rt_mutex_adjust_prio(struct task_struct *task) */ int max_lock_depth = 1024; +static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p) +{ + return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL; +} + /* * Adjust the priority chain. Also used for deadlock detection. * Decreases task's usage by one - may thus free the task. * - * @task: the task owning the mutex (owner) for which a chain walk is probably - * needed + * @task: the task owning the mutex (owner) for which a chain walk is + * probably needed * @deadlock_detect: do we have to carry out deadlock detection? - * @orig_lock: the mutex (can be NULL if we are walking the chain to recheck - * things for a task that has just got its priority adjusted, and - * is waiting on a mutex) + * @orig_lock: the mutex (can be NULL if we are walking the chain to recheck + * things for a task that has just got its priority adjusted, and + * is waiting on a mutex) + * @next_lock: the mutex on which the owner of @orig_lock was blocked before + * we dropped its pi_lock. Is never dereferenced, only used for + * comparison to detect lock chain changes. * @orig_waiter: rt_mutex_waiter struct for the task that has just donated - * its priority to the mutex owner (can be NULL in the case - * depicted above or if the top waiter is gone away and we are - * actually deboosting the owner) - * @top_task: the current top waiter + * its priority to the mutex owner (can be NULL in the case + * depicted above or if the top waiter is gone away and we are + * actually deboosting the owner) + * @top_task: the current top waiter * * Returns 0 or -EDEADLK. */ static int rt_mutex_adjust_prio_chain(struct task_struct *task, int deadlock_detect, struct rt_mutex *orig_lock, + struct rt_mutex *next_lock, struct rt_mutex_waiter *orig_waiter, struct task_struct *top_task) { @@ -314,7 +375,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, } put_task_struct(task); - return deadlock_detect ? -EDEADLK : 0; + return -EDEADLK; } retry: /* @@ -339,6 +400,18 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, goto out_unlock_pi; /* + * We dropped all locks after taking a refcount on @task, so + * the task might have moved on in the lock chain or even left + * the chain completely and blocks now on an unrelated lock or + * on @orig_lock. + * + * We stored the lock on which @task was blocked in @next_lock, + * so we can detect the chain change. + */ + if (next_lock != waiter->lock) + goto out_unlock_pi; + + /* * Drop out, when the task has no waiters. Note, * top_waiter can be NULL, when we are in the deboosting * mode! @@ -377,7 +450,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, if (lock == orig_lock || rt_mutex_owner(lock) == top_task) { debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock); raw_spin_unlock(&lock->wait_lock); - ret = deadlock_detect ? -EDEADLK : 0; + ret = -EDEADLK; goto out_unlock_pi; } @@ -422,11 +495,26 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, __rt_mutex_adjust_prio(task); } + /* + * Check whether the task which owns the current lock is pi + * blocked itself. If yes we store a pointer to the lock for + * the lock chain change detection above. After we dropped + * task->pi_lock next_lock cannot be dereferenced anymore. + */ + next_lock = task_blocked_on_lock(task); + raw_spin_unlock_irqrestore(&task->pi_lock, flags); top_waiter = rt_mutex_top_waiter(lock); raw_spin_unlock(&lock->wait_lock); + /* + * We reached the end of the lock chain. Stop right here. No + * point to go back just to figure that out. + */ + if (!next_lock) + goto out_put_task; + if (!detect_deadlock && waiter != top_waiter) goto out_put_task; @@ -536,8 +624,9 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, { struct task_struct *owner = rt_mutex_owner(lock); struct rt_mutex_waiter *top_waiter = waiter; - unsigned long flags; + struct rt_mutex *next_lock; int chain_walk = 0, res; + unsigned long flags; /* * Early deadlock detection. We really don't want the task to @@ -548,7 +637,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, * which is wrong, as the other waiter is not in a deadlock * situation. */ - if (detect_deadlock && owner == task) + if (owner == task) return -EDEADLK; raw_spin_lock_irqsave(&task->pi_lock, flags); @@ -569,20 +658,28 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, if (!owner) return 0; + raw_spin_lock_irqsave(&owner->pi_lock, flags); if (waiter == rt_mutex_top_waiter(lock)) { - raw_spin_lock_irqsave(&owner->pi_lock, flags); rt_mutex_dequeue_pi(owner, top_waiter); rt_mutex_enqueue_pi(owner, waiter); __rt_mutex_adjust_prio(owner); if (owner->pi_blocked_on) chain_walk = 1; - raw_spin_unlock_irqrestore(&owner->pi_lock, flags); - } - else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) + } else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) { chain_walk = 1; + } - if (!chain_walk) + /* Store the lock on which owner is blocked or NULL */ + next_lock = task_blocked_on_lock(owner); + + raw_spin_unlock_irqrestore(&owner->pi_lock, flags); + /* + * Even if full deadlock detection is on, if the owner is not + * blocked itself, we can avoid finding this out in the chain + * walk. + */ + if (!chain_walk || !next_lock) return 0; /* @@ -594,8 +691,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, raw_spin_unlock(&lock->wait_lock); - res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter, - task); + res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, + next_lock, waiter, task); raw_spin_lock(&lock->wait_lock); @@ -605,7 +702,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, /* * Wake up the next waiter on the lock. * - * Remove the top waiter from the current tasks waiter list and wake it up. + * Remove the top waiter from the current tasks pi waiter list and + * wake it up. * * Called with lock->wait_lock held. */ @@ -626,10 +724,23 @@ static void wakeup_next_waiter(struct rt_mutex *lock) */ rt_mutex_dequeue_pi(current, waiter); - rt_mutex_set_owner(lock, NULL); + /* + * As we are waking up the top waiter, and the waiter stays + * queued on the lock until it gets the lock, this lock + * obviously has waiters. Just set the bit here and this has + * the added benefit of forcing all new tasks into the + * slow path making sure no task of lower priority than + * the top waiter can steal this lock. + */ + lock->owner = (void *) RT_MUTEX_HAS_WAITERS; raw_spin_unlock_irqrestore(¤t->pi_lock, flags); + /* + * It's safe to dereference waiter as it cannot go away as + * long as we hold lock->wait_lock. The waiter task needs to + * acquire it in order to dequeue the waiter. + */ wake_up_process(waiter->task); } @@ -644,8 +755,8 @@ static void remove_waiter(struct rt_mutex *lock, { int first = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); + struct rt_mutex *next_lock = NULL; unsigned long flags; - int chain_walk = 0; raw_spin_lock_irqsave(¤t->pi_lock, flags); rt_mutex_dequeue(lock, waiter); @@ -669,13 +780,13 @@ static void remove_waiter(struct rt_mutex *lock, } __rt_mutex_adjust_prio(owner); - if (owner->pi_blocked_on) - chain_walk = 1; + /* Store the lock on which owner is blocked or NULL */ + next_lock = task_blocked_on_lock(owner); raw_spin_unlock_irqrestore(&owner->pi_lock, flags); } - if (!chain_walk) + if (!next_lock) return; /* gets dropped in rt_mutex_adjust_prio_chain()! */ @@ -683,7 +794,7 @@ static void remove_waiter(struct rt_mutex *lock, raw_spin_unlock(&lock->wait_lock); - rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current); + rt_mutex_adjust_prio_chain(owner, 0, lock, next_lock, NULL, current); raw_spin_lock(&lock->wait_lock); } @@ -696,6 +807,7 @@ static void remove_waiter(struct rt_mutex *lock, void rt_mutex_adjust_pi(struct task_struct *task) { struct rt_mutex_waiter *waiter; + struct rt_mutex *next_lock; unsigned long flags; raw_spin_lock_irqsave(&task->pi_lock, flags); @@ -706,12 +818,13 @@ void rt_mutex_adjust_pi(struct task_struct *task) raw_spin_unlock_irqrestore(&task->pi_lock, flags); return; } - + next_lock = waiter->lock; raw_spin_unlock_irqrestore(&task->pi_lock, flags); /* gets dropped in rt_mutex_adjust_prio_chain()! */ get_task_struct(task); - rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task); + + rt_mutex_adjust_prio_chain(task, 0, NULL, next_lock, NULL, task); } /** @@ -763,6 +876,26 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state, return ret; } +static void rt_mutex_handle_deadlock(int res, int detect_deadlock, + struct rt_mutex_waiter *w) +{ + /* + * If the result is not -EDEADLOCK or the caller requested + * deadlock detection, nothing to do here. + */ + if (res != -EDEADLOCK || detect_deadlock) + return; + + /* + * Yell lowdly and stop the task right here. + */ + rt_mutex_print_deadlock(w); + while (1) { + set_current_state(TASK_INTERRUPTIBLE); + schedule(); + } +} + /* * Slow path lock function: */ @@ -802,8 +935,10 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state, set_current_state(TASK_RUNNING); - if (unlikely(ret)) + if (unlikely(ret)) { remove_waiter(lock, &waiter); + rt_mutex_handle_deadlock(ret, detect_deadlock, &waiter); + } /* * try_to_take_rt_mutex() sets the waiter bit @@ -859,12 +994,49 @@ rt_mutex_slowunlock(struct rt_mutex *lock) rt_mutex_deadlock_account_unlock(current); - if (!rt_mutex_has_waiters(lock)) { - lock->owner = NULL; - raw_spin_unlock(&lock->wait_lock); - return; + /* + * We must be careful here if the fast path is enabled. If we + * have no waiters queued we cannot set owner to NULL here + * because of: + * + * foo->lock->owner = NULL; + * rtmutex_lock(foo->lock); <- fast path + * free = atomic_dec_and_test(foo->refcnt); + * rtmutex_unlock(foo->lock); <- fast path + * if (free) + * kfree(foo); + * raw_spin_unlock(foo->lock->wait_lock); + * + * So for the fastpath enabled kernel: + * + * Nothing can set the waiters bit as long as we hold + * lock->wait_lock. So we do the following sequence: + * + * owner = rt_mutex_owner(lock); + * clear_rt_mutex_waiters(lock); + * raw_spin_unlock(&lock->wait_lock); + * if (cmpxchg(&lock->owner, owner, 0) == owner) + * return; + * goto retry; + * + * The fastpath disabled variant is simple as all access to + * lock->owner is serialized by lock->wait_lock: + * + * lock->owner = NULL; + * raw_spin_unlock(&lock->wait_lock); + */ + while (!rt_mutex_has_waiters(lock)) { + /* Drops lock->wait_lock ! */ + if (unlock_rt_mutex_safe(lock) == true) + return; + /* Relock the rtmutex and try again */ + raw_spin_lock(&lock->wait_lock); } + /* + * The wakeup next waiter path does not suffer from the above + * race. See the comments there. + */ wakeup_next_waiter(lock); raw_spin_unlock(&lock->wait_lock); @@ -1112,7 +1284,8 @@ int rt_mutex_start_proxy_lock(struct rt_mutex *lock, return 1; } - ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock); + /* We enforce deadlock detection for futexes */ + ret = task_blocks_on_rt_mutex(lock, waiter, task, 1); if (ret && !rt_mutex_owner(lock)) { /* diff --git a/kernel/locking/rtmutex.h b/kernel/locking/rtmutex.h index a1a1dd06421d..f6a1f3c133b1 100644 --- a/kernel/locking/rtmutex.h +++ b/kernel/locking/rtmutex.h @@ -24,3 +24,8 @@ #define debug_rt_mutex_print_deadlock(w) do { } while (0) #define debug_rt_mutex_detect_deadlock(w,d) (d) #define debug_rt_mutex_reset_waiter(w) do { } while (0) + +static inline void rt_mutex_print_deadlock(struct rt_mutex_waiter *w) +{ + WARN(1, "rtmutex deadlock detected\n"); +} diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index b4219ff87b8c..dacc32142fcc 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -5,11 +5,17 @@ * * Writer lock-stealing by Alex Shi <alex.shi@intel.com> * and Michel Lespinasse <walken@google.com> + * + * Optimistic spinning by Tim Chen <tim.c.chen@intel.com> + * and Davidlohr Bueso <davidlohr@hp.com>. Based on mutexes. */ #include <linux/rwsem.h> #include <linux/sched.h> #include <linux/init.h> #include <linux/export.h> +#include <linux/sched/rt.h> + +#include "mcs_spinlock.h" /* * Guide to the rw_semaphore's count field for common values. @@ -76,6 +82,10 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, sem->count = RWSEM_UNLOCKED_VALUE; raw_spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); +#ifdef CONFIG_SMP + sem->owner = NULL; + sem->osq = NULL; +#endif } EXPORT_SYMBOL(__init_rwsem); @@ -190,7 +200,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, enum rwsem_wake_type wake_type) } /* - * wait for the read lock to be granted + * Wait for the read lock to be granted */ __visible struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) @@ -237,64 +247,221 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) return sem; } +static inline bool rwsem_try_write_lock(long count, struct rw_semaphore *sem) +{ + if (!(count & RWSEM_ACTIVE_MASK)) { + /* try acquiring the write lock */ + if (sem->count == RWSEM_WAITING_BIAS && + cmpxchg(&sem->count, RWSEM_WAITING_BIAS, + RWSEM_ACTIVE_WRITE_BIAS) == RWSEM_WAITING_BIAS) { + if (!list_is_singular(&sem->wait_list)) + rwsem_atomic_update(RWSEM_WAITING_BIAS, sem); + return true; + } + } + return false; +} + +#ifdef CONFIG_SMP /* - * wait until we successfully acquire the write lock + * Try to acquire write lock before the writer has been put on wait queue. + */ +static inline bool rwsem_try_write_lock_unqueued(struct rw_semaphore *sem) +{ + long old, count = ACCESS_ONCE(sem->count); + + while (true) { + if (!(count == 0 || count == RWSEM_WAITING_BIAS)) + return false; + + old = cmpxchg(&sem->count, count, count + RWSEM_ACTIVE_WRITE_BIAS); + if (old == count) + return true; + + count = old; + } +} + +static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem) +{ + struct task_struct *owner; + bool on_cpu = true; + + if (need_resched()) + return 0; + + rcu_read_lock(); + owner = ACCESS_ONCE(sem->owner); + if (owner) + on_cpu = owner->on_cpu; + rcu_read_unlock(); + + /* + * If sem->owner is not set, the rwsem owner may have + * just acquired it and not set the owner yet or the rwsem + * has been released. + */ + return on_cpu; +} + +static inline bool owner_running(struct rw_semaphore *sem, + struct task_struct *owner) +{ + if (sem->owner != owner) + return false; + + /* + * Ensure we emit the owner->on_cpu, dereference _after_ checking + * sem->owner still matches owner, if that fails, owner might + * point to free()d memory, if it still matches, the rcu_read_lock() + * ensures the memory stays valid. + */ + barrier(); + + return owner->on_cpu; +} + +static noinline +bool rwsem_spin_on_owner(struct rw_semaphore *sem, struct task_struct *owner) +{ + rcu_read_lock(); + while (owner_running(sem, owner)) { + if (need_resched()) + break; + + arch_mutex_cpu_relax(); + } + rcu_read_unlock(); + + /* + * We break out the loop above on need_resched() or when the + * owner changed, which is a sign for heavy contention. Return + * success only when sem->owner is NULL. + */ + return sem->owner == NULL; +} + +static bool rwsem_optimistic_spin(struct rw_semaphore *sem) +{ + struct task_struct *owner; + bool taken = false; + + preempt_disable(); + + /* sem->wait_lock should not be held when doing optimistic spinning */ + if (!rwsem_can_spin_on_owner(sem)) + goto done; + + if (!osq_lock(&sem->osq)) + goto done; + + while (true) { + owner = ACCESS_ONCE(sem->owner); + if (owner && !rwsem_spin_on_owner(sem, owner)) + break; + + /* wait_lock will be acquired if write_lock is obtained */ + if (rwsem_try_write_lock_unqueued(sem)) { + taken = true; + break; + } + + /* + * When there's no owner, we might have preempted between the + * owner acquiring the lock and setting the owner field. If + * we're an RT task that will live-lock because we won't let + * the owner complete. + */ + if (!owner && (need_resched() || rt_task(current))) + break; + + /* + * The cpu_relax() call is a compiler barrier which forces + * everything in this loop to be re-loaded. We don't need + * memory barriers as we'll eventually observe the right + * values at the cost of a few extra spins. + */ + arch_mutex_cpu_relax(); + } + osq_unlock(&sem->osq); +done: + preempt_enable(); + return taken; +} + +#else +static bool rwsem_optimistic_spin(struct rw_semaphore *sem) +{ + return false; +} +#endif + +/* + * Wait until we successfully acquire the write lock */ __visible struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem) { - long count, adjustment = -RWSEM_ACTIVE_WRITE_BIAS; + long count; + bool waiting = true; /* any queued threads before us */ struct rwsem_waiter waiter; - struct task_struct *tsk = current; - /* set up my own style of waitqueue */ - waiter.task = tsk; + /* undo write bias from down_write operation, stop active locking */ + count = rwsem_atomic_update(-RWSEM_ACTIVE_WRITE_BIAS, sem); + + /* do optimistic spinning and steal lock if possible */ + if (rwsem_optimistic_spin(sem)) + return sem; + + /* + * Optimistic spinning failed, proceed to the slowpath + * and block until we can acquire the sem. + */ + waiter.task = current; waiter.type = RWSEM_WAITING_FOR_WRITE; raw_spin_lock_irq(&sem->wait_lock); + + /* account for this before adding a new element to the list */ if (list_empty(&sem->wait_list)) - adjustment += RWSEM_WAITING_BIAS; + waiting = false; + list_add_tail(&waiter.list, &sem->wait_list); /* we're now waiting on the lock, but no longer actively locking */ - count = rwsem_atomic_update(adjustment, sem); + if (waiting) { + count = ACCESS_ONCE(sem->count); - /* If there were already threads queued before us and there are no - * active writers, the lock must be read owned; so we try to wake - * any read locks that were queued ahead of us. */ - if (count > RWSEM_WAITING_BIAS && - adjustment == -RWSEM_ACTIVE_WRITE_BIAS) - sem = __rwsem_do_wake(sem, RWSEM_WAKE_READERS); + /* + * If there were already threads queued before us and there are + * no active writers, the lock must be read owned; so we try to + * wake any read locks that were queued ahead of us. + */ + if (count > RWSEM_WAITING_BIAS) + sem = __rwsem_do_wake(sem, RWSEM_WAKE_READERS); + + } else + count = rwsem_atomic_update(RWSEM_WAITING_BIAS, sem); /* wait until we successfully acquire the lock */ - set_task_state(tsk, TASK_UNINTERRUPTIBLE); + set_current_state(TASK_UNINTERRUPTIBLE); while (true) { - if (!(count & RWSEM_ACTIVE_MASK)) { - /* Try acquiring the write lock. */ - count = RWSEM_ACTIVE_WRITE_BIAS; - if (!list_is_singular(&sem->wait_list)) - count += RWSEM_WAITING_BIAS; - - if (sem->count == RWSEM_WAITING_BIAS && - cmpxchg(&sem->count, RWSEM_WAITING_BIAS, count) == - RWSEM_WAITING_BIAS) - break; - } - + if (rwsem_try_write_lock(count, sem)) + break; raw_spin_unlock_irq(&sem->wait_lock); /* Block until there are no active lockers. */ do { schedule(); - set_task_state(tsk, TASK_UNINTERRUPTIBLE); + set_current_state(TASK_UNINTERRUPTIBLE); } while ((count = sem->count) & RWSEM_ACTIVE_MASK); raw_spin_lock_irq(&sem->wait_lock); } + __set_current_state(TASK_RUNNING); list_del(&waiter.list); raw_spin_unlock_irq(&sem->wait_lock); - tsk->state = TASK_RUNNING; return sem; } diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index cfff1435bdfb..42f806de49d4 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -12,6 +12,27 @@ #include <linux/atomic.h> +#if defined(CONFIG_SMP) && defined(CONFIG_RWSEM_XCHGADD_ALGORITHM) +static inline void rwsem_set_owner(struct rw_semaphore *sem) +{ + sem->owner = current; +} + +static inline void rwsem_clear_owner(struct rw_semaphore *sem) +{ + sem->owner = NULL; +} + +#else +static inline void rwsem_set_owner(struct rw_semaphore *sem) +{ +} + +static inline void rwsem_clear_owner(struct rw_semaphore *sem) +{ +} +#endif + /* * lock for reading */ @@ -48,6 +69,7 @@ void __sched down_write(struct rw_semaphore *sem) rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); LOCK_CONTENDED(sem, __down_write_trylock, __down_write); + rwsem_set_owner(sem); } EXPORT_SYMBOL(down_write); @@ -59,8 +81,11 @@ int down_write_trylock(struct rw_semaphore *sem) { int ret = __down_write_trylock(sem); - if (ret == 1) + if (ret == 1) { rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_); + rwsem_set_owner(sem); + } + return ret; } @@ -85,6 +110,7 @@ void up_write(struct rw_semaphore *sem) { rwsem_release(&sem->dep_map, 1, _RET_IP_); + rwsem_clear_owner(sem); __up_write(sem); } @@ -99,6 +125,7 @@ void downgrade_write(struct rw_semaphore *sem) * lockdep: a downgraded write will live on as a write * dependency. */ + rwsem_clear_owner(sem); __downgrade_write(sem); } @@ -122,6 +149,7 @@ void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) rwsem_acquire_nest(&sem->dep_map, 0, 0, nest, _RET_IP_); LOCK_CONTENDED(sem, __down_write_trylock, __down_write); + rwsem_set_owner(sem); } EXPORT_SYMBOL(_down_write_nest_lock); @@ -141,6 +169,7 @@ void down_write_nested(struct rw_semaphore *sem, int subclass) rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_); LOCK_CONTENDED(sem, __down_write_trylock, __down_write); + rwsem_set_owner(sem); } EXPORT_SYMBOL(down_write_nested); diff --git a/kernel/module.c b/kernel/module.c index 079c4615607d..81e727cf6df9 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3020,21 +3020,6 @@ static int do_init_module(struct module *mod) */ current->flags &= ~PF_USED_ASYNC; - blocking_notifier_call_chain(&module_notify_list, - MODULE_STATE_COMING, mod); - - /* Set RO and NX regions for core */ - set_section_ro_nx(mod->module_core, - mod->core_text_size, - mod->core_ro_size, - mod->core_size); - - /* Set RO and NX regions for init */ - set_section_ro_nx(mod->module_init, - mod->init_text_size, - mod->init_ro_size, - mod->init_size); - do_mod_ctors(mod); /* Start the module */ if (mod->init != NULL) @@ -3165,9 +3150,26 @@ static int complete_formation(struct module *mod, struct load_info *info) /* This relies on module_mutex for list integrity. */ module_bug_finalize(info->hdr, info->sechdrs, mod); + /* Set RO and NX regions for core */ + set_section_ro_nx(mod->module_core, + mod->core_text_size, + mod->core_ro_size, + mod->core_size); + + /* Set RO and NX regions for init */ + set_section_ro_nx(mod->module_init, + mod->init_text_size, + mod->init_ro_size, + mod->init_size); + /* Mark state as coming so strong_try_module_get() ignores us, * but kallsyms etc. can see us. */ mod->state = MODULE_STATE_COMING; + mutex_unlock(&module_mutex); + + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_COMING, mod); + return 0; out: mutex_unlock(&module_mutex); @@ -3190,6 +3192,7 @@ static int load_module(struct load_info *info, const char __user *uargs, { struct module *mod; long err; + char *after_dashes; err = module_sig_check(info); if (err) @@ -3277,10 +3280,15 @@ static int load_module(struct load_info *info, const char __user *uargs, goto ddebug_cleanup; /* Module is ready to execute: parsing args may do that. */ - err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, - -32768, 32767, unknown_module_param_cb); - if (err < 0) + after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, + -32768, 32767, unknown_module_param_cb); + if (IS_ERR(after_dashes)) { + err = PTR_ERR(after_dashes); goto bug_cleanup; + } else if (after_dashes) { + pr_warn("%s: parameters '%s' after `--' ignored\n", + mod->name, after_dashes); + } /* Link in to syfs. */ err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); diff --git a/kernel/notifier.c b/kernel/notifier.c index db4c8b08a50c..4803da6eab62 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -71,9 +71,9 @@ static int notifier_chain_unregister(struct notifier_block **nl, * @returns: notifier_call_chain returns the value returned by the * last notifier function called. */ -static int __kprobes notifier_call_chain(struct notifier_block **nl, - unsigned long val, void *v, - int nr_to_call, int *nr_calls) +static int notifier_call_chain(struct notifier_block **nl, + unsigned long val, void *v, + int nr_to_call, int *nr_calls) { int ret = NOTIFY_DONE; struct notifier_block *nb, *next_nb; @@ -102,6 +102,7 @@ static int __kprobes notifier_call_chain(struct notifier_block **nl, } return ret; } +NOKPROBE_SYMBOL(notifier_call_chain); /* * Atomic notifier chain routines. Registration and unregistration @@ -172,9 +173,9 @@ EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); * Otherwise the return value is the return value * of the last notifier function called. */ -int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh, - unsigned long val, void *v, - int nr_to_call, int *nr_calls) +int __atomic_notifier_call_chain(struct atomic_notifier_head *nh, + unsigned long val, void *v, + int nr_to_call, int *nr_calls) { int ret; @@ -184,13 +185,15 @@ int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh, return ret; } EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); +NOKPROBE_SYMBOL(__atomic_notifier_call_chain); -int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh, - unsigned long val, void *v) +int atomic_notifier_call_chain(struct atomic_notifier_head *nh, + unsigned long val, void *v) { return __atomic_notifier_call_chain(nh, val, v, -1, NULL); } EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); +NOKPROBE_SYMBOL(atomic_notifier_call_chain); /* * Blocking notifier chain routines. All access to the chain is @@ -527,7 +530,7 @@ EXPORT_SYMBOL_GPL(srcu_init_notifier_head); static ATOMIC_NOTIFIER_HEAD(die_chain); -int notrace __kprobes notify_die(enum die_val val, const char *str, +int notrace notify_die(enum die_val val, const char *str, struct pt_regs *regs, long err, int trap, int sig) { struct die_args args = { @@ -540,6 +543,7 @@ int notrace __kprobes notify_die(enum die_val val, const char *str, }; return atomic_notifier_call_chain(&die_chain, val, &args); } +NOKPROBE_SYMBOL(notify_die); int register_die_notifier(struct notifier_block *nb) { diff --git a/kernel/params.c b/kernel/params.c index b00142e7f3ba..1e52ca233fd9 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -177,13 +177,13 @@ static char *next_arg(char *args, char **param, char **val) } /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ -int parse_args(const char *doing, - char *args, - const struct kernel_param *params, - unsigned num, - s16 min_level, - s16 max_level, - int (*unknown)(char *param, char *val, const char *doing)) +char *parse_args(const char *doing, + char *args, + const struct kernel_param *params, + unsigned num, + s16 min_level, + s16 max_level, + int (*unknown)(char *param, char *val, const char *doing)) { char *param, *val; @@ -198,6 +198,9 @@ int parse_args(const char *doing, int irq_was_disabled; args = next_arg(args, ¶m, &val); + /* Stop at -- */ + if (!val && strcmp(param, "--") == 0) + return args; irq_was_disabled = irqs_disabled(); ret = parse_one(param, val, doing, params, num, min_level, max_level, unknown); @@ -208,22 +211,22 @@ int parse_args(const char *doing, switch (ret) { case -ENOENT: pr_err("%s: Unknown parameter `%s'\n", doing, param); - return ret; + return ERR_PTR(ret); case -ENOSPC: pr_err("%s: `%s' too large for parameter `%s'\n", doing, val ?: "", param); - return ret; + return ERR_PTR(ret); case 0: break; default: pr_err("%s: `%s' invalid for parameter `%s'\n", doing, val ?: "", param); - return ret; + return ERR_PTR(ret); } } /* All parsed OK. */ - return 0; + return NULL; } /* Lazy bastard, eh? */ diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index df88d55dc436..fcc2611d3f14 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -28,12 +28,14 @@ #include <linux/syscore_ops.h> #include <linux/ctype.h> #include <linux/genhd.h> +#include <trace/events/power.h> #include "power.h" static int nocompress; static int noresume; +static int nohibernate; static int resume_wait; static unsigned int resume_delay; static char resume_file[256] = CONFIG_PM_STD_PARTITION; @@ -61,6 +63,11 @@ bool freezer_test_done; static const struct platform_hibernation_ops *hibernation_ops; +bool hibernation_available(void) +{ + return (nohibernate == 0); +} + /** * hibernation_set_ops - Set the global hibernate operations. * @ops: Hibernation operations to use in subsequent hibernation transitions. @@ -292,7 +299,9 @@ static int create_image(int platform_mode) in_suspend = 1; save_processor_state(); + trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true); error = swsusp_arch_suspend(); + trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false); if (error) printk(KERN_ERR "PM: Error %d creating hibernation image\n", error); @@ -639,6 +648,11 @@ int hibernate(void) { int error; + if (!hibernation_available()) { + pr_debug("PM: Hibernation not available.\n"); + return -EPERM; + } + lock_system_sleep(); /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { @@ -731,7 +745,7 @@ static int software_resume(void) /* * If the user said "noresume".. bail out early. */ - if (noresume) + if (noresume || !hibernation_available()) return 0; /* @@ -897,6 +911,9 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, int i; char *start = buf; + if (!hibernation_available()) + return sprintf(buf, "[disabled]\n"); + for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { if (!hibernation_modes[i]) continue; @@ -931,6 +948,9 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, char *p; int mode = HIBERNATION_INVALID; + if (!hibernation_available()) + return -EPERM; + p = memchr(buf, '\n', n); len = p ? p - buf : n; @@ -1098,6 +1118,10 @@ static int __init hibernate_setup(char *str) noresume = 1; else if (!strncmp(str, "nocompress", 10)) nocompress = 1; + else if (!strncmp(str, "no", 2)) { + noresume = 1; + nohibernate = 1; + } return 1; } @@ -1122,9 +1146,23 @@ static int __init resumedelay_setup(char *str) return 1; } +static int __init nohibernate_setup(char *str) +{ + noresume = 1; + nohibernate = 1; + return 1; +} + +static int __init kaslr_nohibernate_setup(char *str) +{ + return nohibernate_setup(str); +} + __setup("noresume", noresume_setup); __setup("resume_offset=", resume_offset_setup); __setup("resume=", resume_setup); __setup("hibernate=", hibernate_setup); __setup("resumewait", resumewait_setup); __setup("resumedelay=", resumedelay_setup); +__setup("nohibernate", nohibernate_setup); +__setup("kaslr", kaslr_nohibernate_setup); diff --git a/kernel/power/main.c b/kernel/power/main.c index 573410d6647e..8e90f330f139 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -300,13 +300,11 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, s += sprintf(s,"%s ", pm_states[i].label); #endif -#ifdef CONFIG_HIBERNATION - s += sprintf(s, "%s\n", "disk"); -#else + if (hibernation_available()) + s += sprintf(s, "disk "); if (s != buf) /* convert the last space to a newline */ *(s-1) = '\n'; -#endif return (s - buf); } diff --git a/kernel/power/process.c b/kernel/power/process.c index 06ec8869dbf1..0ca8d83e2369 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -17,6 +17,7 @@ #include <linux/delay.h> #include <linux/workqueue.h> #include <linux/kmod.h> +#include <trace/events/power.h> /* * Timeout for stopping processes @@ -175,6 +176,7 @@ void thaw_processes(void) struct task_struct *g, *p; struct task_struct *curr = current; + trace_suspend_resume(TPS("thaw_processes"), 0, true); if (pm_freezing) atomic_dec(&system_freezing_cnt); pm_freezing = false; @@ -201,6 +203,7 @@ void thaw_processes(void) schedule(); printk("done.\n"); + trace_suspend_resume(TPS("thaw_processes"), 0, false); } void thaw_kernel_threads(void) diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 963e6d0f050b..4dd8822f732a 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -177,7 +177,9 @@ static int suspend_prepare(suspend_state_t state) if (error) goto Finish; + trace_suspend_resume(TPS("freeze_processes"), 0, true); error = suspend_freeze_processes(); + trace_suspend_resume(TPS("freeze_processes"), 0, false); if (!error) return 0; @@ -240,7 +242,9 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) * all the devices are suspended. */ if (state == PM_SUSPEND_FREEZE) { + trace_suspend_resume(TPS("machine_suspend"), state, true); freeze_enter(); + trace_suspend_resume(TPS("machine_suspend"), state, false); goto Platform_wake; } @@ -256,7 +260,11 @@ static int suspend_enter(suspend_state_t state, bool *wakeup) if (!error) { *wakeup = pm_wakeup_pending(); if (!(suspend_test(TEST_CORE) || *wakeup)) { + trace_suspend_resume(TPS("machine_suspend"), + state, true); error = suspend_ops->enter(state); + trace_suspend_resume(TPS("machine_suspend"), + state, false); events_check_enabled = false; } syscore_resume(); @@ -294,7 +302,6 @@ int suspend_devices_and_enter(suspend_state_t state) if (need_suspend_ops(state) && !suspend_ops) return -ENOSYS; - trace_machine_suspend(state); if (need_suspend_ops(state) && suspend_ops->begin) { error = suspend_ops->begin(state); if (error) @@ -331,7 +338,6 @@ int suspend_devices_and_enter(suspend_state_t state) else if (state == PM_SUSPEND_FREEZE && freeze_ops->end) freeze_ops->end(); - trace_machine_suspend(PWR_EVENT_EXIT); return error; Recover_platform: @@ -365,6 +371,7 @@ static int enter_state(suspend_state_t state) { int error; + trace_suspend_resume(TPS("suspend_enter"), state, true); if (state == PM_SUSPEND_FREEZE) { #ifdef CONFIG_PM_DEBUG if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) { @@ -382,9 +389,11 @@ static int enter_state(suspend_state_t state) if (state == PM_SUSPEND_FREEZE) freeze_begin(); + trace_suspend_resume(TPS("sync_filesystems"), 0, true); printk(KERN_INFO "PM: Syncing filesystems ... "); sys_sync(); printk("done.\n"); + trace_suspend_resume(TPS("sync_filesystems"), 0, false); pr_debug("PM: Preparing system for %s sleep\n", pm_states[state].label); error = suspend_prepare(state); @@ -394,6 +403,7 @@ static int enter_state(suspend_state_t state) if (suspend_test(TEST_FREEZER)) goto Finish; + trace_suspend_resume(TPS("suspend_enter"), state, false); pr_debug("PM: Entering %s sleep\n", pm_states[state].label); pm_restrict_gfp_mask(); error = suspend_devices_and_enter(state); diff --git a/kernel/power/user.c b/kernel/power/user.c index 98d357584cd6..526e8911460a 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -49,6 +49,9 @@ static int snapshot_open(struct inode *inode, struct file *filp) struct snapshot_data *data; int error; + if (!hibernation_available()) + return -EPERM; + lock_system_sleep(); if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index ea2d5f6962ed..13e839dbca07 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1416,9 +1416,10 @@ static int have_callable_console(void) /* * Can we actually use the console at this time on this cpu? * - * Console drivers may assume that per-cpu resources have been allocated. So - * unless they're explicitly marked as being able to cope (CON_ANYTIME) don't - * call them until this CPU is officially up. + * Console drivers may assume that per-cpu resources have + * been allocated. So unless they're explicitly marked as + * being able to cope (CON_ANYTIME) don't call them until + * this CPU is officially up. */ static inline int can_use_console(unsigned int cpu) { @@ -1431,10 +1432,8 @@ static inline int can_use_console(unsigned int cpu) * console_lock held, and 'console_locked' set) if it * is successful, false otherwise. */ -static int console_trylock_for_printk(void) +static int console_trylock_for_printk(unsigned int cpu) { - unsigned int cpu = smp_processor_id(); - if (!console_trylock()) return 0; /* @@ -1609,8 +1608,7 @@ asmlinkage int vprintk_emit(int facility, int level, */ if (!oops_in_progress && !lockdep_recursing(current)) { recursion_bug = 1; - local_irq_restore(flags); - return 0; + goto out_restore_irqs; } zap_locks(); } @@ -1718,27 +1716,21 @@ asmlinkage int vprintk_emit(int facility, int level, logbuf_cpu = UINT_MAX; raw_spin_unlock(&logbuf_lock); - lockdep_on(); - local_irq_restore(flags); /* If called from the scheduler, we can not call up(). */ - if (in_sched) - return printed_len; - - /* - * Disable preemption to avoid being preempted while holding - * console_sem which would prevent anyone from printing to console - */ - preempt_disable(); - /* - * Try to acquire and then immediately release the console semaphore. - * The release will print out buffers and wake up /dev/kmsg and syslog() - * users. - */ - if (console_trylock_for_printk()) - console_unlock(); - preempt_enable(); + if (!in_sched) { + /* + * Try to acquire and then immediately release the console + * semaphore. The release will print out buffers and wake up + * /dev/kmsg and syslog() users. + */ + if (console_trylock_for_printk(this_cpu)) + console_unlock(); + } + lockdep_on(); +out_restore_irqs: + local_irq_restore(flags); return printed_len; } EXPORT_SYMBOL(vprintk_emit); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 48e78b657d23..3bdf01b494fe 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -535,7 +535,7 @@ static inline void init_hrtick(void) __old; \ }) -#ifdef TIF_POLLING_NRFLAG +#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) /* * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, * this avoids any races wrt polling state changes and thereby avoids @@ -546,12 +546,44 @@ static bool set_nr_and_not_polling(struct task_struct *p) struct thread_info *ti = task_thread_info(p); return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); } + +/* + * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. + * + * If this returns true, then the idle task promises to call + * sched_ttwu_pending() and reschedule soon. + */ +static bool set_nr_if_polling(struct task_struct *p) +{ + struct thread_info *ti = task_thread_info(p); + typeof(ti->flags) old, val = ACCESS_ONCE(ti->flags); + + for (;;) { + if (!(val & _TIF_POLLING_NRFLAG)) + return false; + if (val & _TIF_NEED_RESCHED) + return true; + old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED); + if (old == val) + break; + val = old; + } + return true; +} + #else static bool set_nr_and_not_polling(struct task_struct *p) { set_tsk_need_resched(p); return true; } + +#ifdef CONFIG_SMP +static bool set_nr_if_polling(struct task_struct *p) +{ + return false; +} +#endif #endif /* @@ -580,6 +612,8 @@ void resched_task(struct task_struct *p) if (set_nr_and_not_polling(p)) smp_send_reschedule(cpu); + else + trace_sched_wake_idle_without_ipi(cpu); } void resched_cpu(int cpu) @@ -642,27 +676,10 @@ static void wake_up_idle_cpu(int cpu) if (cpu == smp_processor_id()) return; - /* - * This is safe, as this function is called with the timer - * wheel base lock of (cpu) held. When the CPU is on the way - * to idle and has not yet set rq->curr to idle then it will - * be serialized on the timer wheel base lock and take the new - * timer into account automatically. - */ - if (rq->curr != rq->idle) - return; - - /* - * We can set TIF_RESCHED on the idle task of the other CPU - * lockless. The worst case is that the other CPU runs the - * idle task through an additional NOOP schedule() - */ - set_tsk_need_resched(rq->idle); - - /* NEED_RESCHED must be visible before we test polling */ - smp_mb(); - if (!tsk_is_polling(rq->idle)) + if (set_nr_and_not_polling(rq->idle)) smp_send_reschedule(cpu); + else + trace_sched_wake_idle_without_ipi(cpu); } static bool wake_up_full_nohz_cpu(int cpu) @@ -888,7 +905,7 @@ static void update_rq_clock_task(struct rq *rq, s64 delta) rq->clock_task += delta; #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) - if ((irq_delta + steal) && sched_feat(NONTASK_POWER)) + if ((irq_delta + steal) && sched_feat(NONTASK_CAPACITY)) sched_rt_avg_update(rq, irq_delta + steal); #endif } @@ -1521,13 +1538,17 @@ static int ttwu_remote(struct task_struct *p, int wake_flags) } #ifdef CONFIG_SMP -static void sched_ttwu_pending(void) +void sched_ttwu_pending(void) { struct rq *rq = this_rq(); struct llist_node *llist = llist_del_all(&rq->wake_list); struct task_struct *p; + unsigned long flags; - raw_spin_lock(&rq->lock); + if (!llist) + return; + + raw_spin_lock_irqsave(&rq->lock, flags); while (llist) { p = llist_entry(llist, struct task_struct, wake_entry); @@ -1535,7 +1556,7 @@ static void sched_ttwu_pending(void) ttwu_do_activate(rq, p, 0); } - raw_spin_unlock(&rq->lock); + raw_spin_unlock_irqrestore(&rq->lock, flags); } void scheduler_ipi(void) @@ -1581,8 +1602,14 @@ void scheduler_ipi(void) static void ttwu_queue_remote(struct task_struct *p, int cpu) { - if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) - smp_send_reschedule(cpu); + struct rq *rq = cpu_rq(cpu); + + if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) { + if (!set_nr_if_polling(rq->idle)) + smp_send_reschedule(cpu); + else + trace_sched_wake_idle_without_ipi(cpu); + } } bool cpus_share_cache(int this_cpu, int that_cpu) @@ -2527,7 +2554,7 @@ notrace unsigned long get_parent_ip(unsigned long addr) #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ defined(CONFIG_PREEMPT_TRACER)) -void __kprobes preempt_count_add(int val) +void preempt_count_add(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2553,8 +2580,9 @@ void __kprobes preempt_count_add(int val) } } EXPORT_SYMBOL(preempt_count_add); +NOKPROBE_SYMBOL(preempt_count_add); -void __kprobes preempt_count_sub(int val) +void preempt_count_sub(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2575,6 +2603,7 @@ void __kprobes preempt_count_sub(int val) __preempt_count_sub(val); } EXPORT_SYMBOL(preempt_count_sub); +NOKPROBE_SYMBOL(preempt_count_sub); #endif @@ -2857,6 +2886,7 @@ asmlinkage __visible void __sched notrace preempt_schedule(void) barrier(); } while (need_resched()); } +NOKPROBE_SYMBOL(preempt_schedule); EXPORT_SYMBOL(preempt_schedule); #endif /* CONFIG_PREEMPT */ @@ -4216,7 +4246,7 @@ EXPORT_SYMBOL(yield); * false (0) if we failed to boost the target. * -ESRCH if there's no task to yield to. */ -bool __sched yield_to(struct task_struct *p, bool preempt) +int __sched yield_to(struct task_struct *p, bool preempt) { struct task_struct *curr = current; struct rq *rq, *p_rq; @@ -5242,14 +5272,13 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, } /* - * Even though we initialize ->power to something semi-sane, - * we leave power_orig unset. This allows us to detect if + * Even though we initialize ->capacity to something semi-sane, + * we leave capacity_orig unset. This allows us to detect if * domain iteration is still funny without causing /0 traps. */ - if (!group->sgp->power_orig) { + if (!group->sgc->capacity_orig) { printk(KERN_CONT "\n"); - printk(KERN_ERR "ERROR: domain->cpu_power not " - "set\n"); + printk(KERN_ERR "ERROR: domain->cpu_capacity not set\n"); break; } @@ -5271,9 +5300,9 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); printk(KERN_CONT " %s", str); - if (group->sgp->power != SCHED_POWER_SCALE) { - printk(KERN_CONT " (cpu_power = %d)", - group->sgp->power); + if (group->sgc->capacity != SCHED_CAPACITY_SCALE) { + printk(KERN_CONT " (cpu_capacity = %d)", + group->sgc->capacity); } group = group->next; @@ -5331,7 +5360,7 @@ static int sd_degenerate(struct sched_domain *sd) SD_BALANCE_NEWIDLE | SD_BALANCE_FORK | SD_BALANCE_EXEC | - SD_SHARE_CPUPOWER | + SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES | SD_SHARE_POWERDOMAIN)) { if (sd->groups != sd->groups->next) @@ -5362,7 +5391,7 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) SD_BALANCE_NEWIDLE | SD_BALANCE_FORK | SD_BALANCE_EXEC | - SD_SHARE_CPUPOWER | + SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES | SD_PREFER_SIBLING | SD_SHARE_POWERDOMAIN); @@ -5487,7 +5516,7 @@ static struct root_domain *alloc_rootdomain(void) return rd; } -static void free_sched_groups(struct sched_group *sg, int free_sgp) +static void free_sched_groups(struct sched_group *sg, int free_sgc) { struct sched_group *tmp, *first; @@ -5498,8 +5527,8 @@ static void free_sched_groups(struct sched_group *sg, int free_sgp) do { tmp = sg->next; - if (free_sgp && atomic_dec_and_test(&sg->sgp->ref)) - kfree(sg->sgp); + if (free_sgc && atomic_dec_and_test(&sg->sgc->ref)) + kfree(sg->sgc); kfree(sg); sg = tmp; @@ -5517,7 +5546,7 @@ static void free_sched_domain(struct rcu_head *rcu) if (sd->flags & SD_OVERLAP) { free_sched_groups(sd->groups, 1); } else if (atomic_dec_and_test(&sd->groups->ref)) { - kfree(sd->groups->sgp); + kfree(sd->groups->sgc); kfree(sd->groups); } kfree(sd); @@ -5728,17 +5757,17 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu) cpumask_or(covered, covered, sg_span); - sg->sgp = *per_cpu_ptr(sdd->sgp, i); - if (atomic_inc_return(&sg->sgp->ref) == 1) + sg->sgc = *per_cpu_ptr(sdd->sgc, i); + if (atomic_inc_return(&sg->sgc->ref) == 1) build_group_mask(sd, sg); /* - * Initialize sgp->power such that even if we mess up the + * Initialize sgc->capacity such that even if we mess up the * domains and no possible iteration will get us here, we won't * die on a /0 trap. */ - sg->sgp->power = SCHED_POWER_SCALE * cpumask_weight(sg_span); - sg->sgp->power_orig = sg->sgp->power; + sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); + sg->sgc->capacity_orig = sg->sgc->capacity; /* * Make sure the first group of this domain contains the @@ -5776,8 +5805,8 @@ static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) if (sg) { *sg = *per_cpu_ptr(sdd->sg, cpu); - (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu); - atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */ + (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu); + atomic_set(&(*sg)->sgc->ref, 1); /* for claim_allocations */ } return cpu; @@ -5786,7 +5815,7 @@ static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) /* * build_sched_groups will build a circular linked list of the groups * covered by the given span, and will set each group's ->cpumask correctly, - * and ->cpu_power to 0. + * and ->cpu_capacity to 0. * * Assumes the sched_domain tree is fully constructed */ @@ -5840,16 +5869,16 @@ build_sched_groups(struct sched_domain *sd, int cpu) } /* - * Initialize sched groups cpu_power. + * Initialize sched groups cpu_capacity. * - * cpu_power indicates the capacity of sched group, which is used while + * cpu_capacity indicates the capacity of sched group, which is used while * distributing the load between different sched groups in a sched domain. - * Typically cpu_power for all the groups in a sched domain will be same unless - * there are asymmetries in the topology. If there are asymmetries, group - * having more cpu_power will pickup more load compared to the group having - * less cpu_power. + * Typically cpu_capacity for all the groups in a sched domain will be same + * unless there are asymmetries in the topology. If there are asymmetries, + * group having more cpu_capacity will pickup more load compared to the + * group having less cpu_capacity. */ -static void init_sched_groups_power(int cpu, struct sched_domain *sd) +static void init_sched_groups_capacity(int cpu, struct sched_domain *sd) { struct sched_group *sg = sd->groups; @@ -5863,8 +5892,8 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) if (cpu != group_balance_cpu(sg)) return; - update_group_power(sd, cpu); - atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight); + update_group_capacity(sd, cpu); + atomic_set(&sg->sgc->nr_busy_cpus, sg->group_weight); } /* @@ -5955,8 +5984,8 @@ static void claim_allocations(int cpu, struct sched_domain *sd) if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) *per_cpu_ptr(sdd->sg, cpu) = NULL; - if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref)) - *per_cpu_ptr(sdd->sgp, cpu) = NULL; + if (atomic_read(&(*per_cpu_ptr(sdd->sgc, cpu))->ref)) + *per_cpu_ptr(sdd->sgc, cpu) = NULL; } #ifdef CONFIG_NUMA @@ -5969,7 +5998,7 @@ static int sched_domains_curr_level; /* * SD_flags allowed in topology descriptions. * - * SD_SHARE_CPUPOWER - describes SMT topologies + * SD_SHARE_CPUCAPACITY - describes SMT topologies * SD_SHARE_PKG_RESOURCES - describes shared caches * SD_NUMA - describes NUMA topologies * SD_SHARE_POWERDOMAIN - describes shared power domain @@ -5978,7 +6007,7 @@ static int sched_domains_curr_level; * SD_ASYM_PACKING - describes SMT quirks */ #define TOPOLOGY_SD_FLAGS \ - (SD_SHARE_CPUPOWER | \ + (SD_SHARE_CPUCAPACITY | \ SD_SHARE_PKG_RESOURCES | \ SD_NUMA | \ SD_ASYM_PACKING | \ @@ -6024,7 +6053,7 @@ sd_init(struct sched_domain_topology_level *tl, int cpu) | 1*SD_BALANCE_FORK | 0*SD_BALANCE_WAKE | 1*SD_WAKE_AFFINE - | 0*SD_SHARE_CPUPOWER + | 0*SD_SHARE_CPUCAPACITY | 0*SD_SHARE_PKG_RESOURCES | 0*SD_SERIALIZE | 0*SD_PREFER_SIBLING @@ -6046,7 +6075,7 @@ sd_init(struct sched_domain_topology_level *tl, int cpu) * Convert topological properties into behaviour. */ - if (sd->flags & SD_SHARE_CPUPOWER) { + if (sd->flags & SD_SHARE_CPUCAPACITY) { sd->imbalance_pct = 110; sd->smt_gain = 1178; /* ~15% */ @@ -6358,14 +6387,14 @@ static int __sdt_alloc(const struct cpumask *cpu_map) if (!sdd->sg) return -ENOMEM; - sdd->sgp = alloc_percpu(struct sched_group_power *); - if (!sdd->sgp) + sdd->sgc = alloc_percpu(struct sched_group_capacity *); + if (!sdd->sgc) return -ENOMEM; for_each_cpu(j, cpu_map) { struct sched_domain *sd; struct sched_group *sg; - struct sched_group_power *sgp; + struct sched_group_capacity *sgc; sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), GFP_KERNEL, cpu_to_node(j)); @@ -6383,12 +6412,12 @@ static int __sdt_alloc(const struct cpumask *cpu_map) *per_cpu_ptr(sdd->sg, j) = sg; - sgp = kzalloc_node(sizeof(struct sched_group_power) + cpumask_size(), + sgc = kzalloc_node(sizeof(struct sched_group_capacity) + cpumask_size(), GFP_KERNEL, cpu_to_node(j)); - if (!sgp) + if (!sgc) return -ENOMEM; - *per_cpu_ptr(sdd->sgp, j) = sgp; + *per_cpu_ptr(sdd->sgc, j) = sgc; } } @@ -6415,15 +6444,15 @@ static void __sdt_free(const struct cpumask *cpu_map) if (sdd->sg) kfree(*per_cpu_ptr(sdd->sg, j)); - if (sdd->sgp) - kfree(*per_cpu_ptr(sdd->sgp, j)); + if (sdd->sgc) + kfree(*per_cpu_ptr(sdd->sgc, j)); } free_percpu(sdd->sd); sdd->sd = NULL; free_percpu(sdd->sg); sdd->sg = NULL; - free_percpu(sdd->sgp); - sdd->sgp = NULL; + free_percpu(sdd->sgc); + sdd->sgc = NULL; } } @@ -6493,14 +6522,14 @@ static int build_sched_domains(const struct cpumask *cpu_map, } } - /* Calculate CPU power for physical packages and nodes */ + /* Calculate CPU capacity for physical packages and nodes */ for (i = nr_cpumask_bits-1; i >= 0; i--) { if (!cpumask_test_cpu(i, cpu_map)) continue; for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { claim_allocations(i, sd); - init_sched_groups_power(i, sd); + init_sched_groups_capacity(i, sd); } } @@ -6943,7 +6972,7 @@ void __init sched_init(void) #ifdef CONFIG_SMP rq->sd = NULL; rq->rd = NULL; - rq->cpu_power = SCHED_POWER_SCALE; + rq->cpu_capacity = SCHED_CAPACITY_SCALE; rq->post_schedule = 0; rq->active_balance = 0; rq->next_balance = jiffies; @@ -7669,7 +7698,7 @@ cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) { struct task_group *tg = css_tg(css); - struct task_group *parent = css_tg(css_parent(css)); + struct task_group *parent = css_tg(css->parent); if (parent) sched_online_group(tg, parent); diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index c143ee380e3a..9cf350c94ec4 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -46,7 +46,7 @@ static inline struct cpuacct *task_ca(struct task_struct *tsk) static inline struct cpuacct *parent_ca(struct cpuacct *ca) { - return css_ca(css_parent(&ca->css)); + return css_ca(ca->css.parent); } static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage); diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 2b8cbf09d1a4..fc4f98b1258f 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -57,8 +57,6 @@ void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime) dl_b->dl_runtime = runtime; } -extern unsigned long to_ratio(u64 period, u64 runtime); - void init_dl_bw(struct dl_bw *dl_b) { raw_spin_lock_init(&dl_b->lock); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9855e87d671a..fea7d3335e1f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1017,7 +1017,7 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page, static unsigned long weighted_cpuload(const int cpu); static unsigned long source_load(int cpu, int type); static unsigned long target_load(int cpu, int type); -static unsigned long power_of(int cpu); +static unsigned long capacity_of(int cpu); static long effective_load(struct task_group *tg, int cpu, long wl, long wg); /* Cached statistics for all CPUs within a node */ @@ -1026,11 +1026,11 @@ struct numa_stats { unsigned long load; /* Total compute capacity of CPUs on a node */ - unsigned long power; + unsigned long compute_capacity; /* Approximate capacity in terms of runnable tasks on a node */ - unsigned long capacity; - int has_capacity; + unsigned long task_capacity; + int has_free_capacity; }; /* @@ -1046,7 +1046,7 @@ static void update_numa_stats(struct numa_stats *ns, int nid) ns->nr_running += rq->nr_running; ns->load += weighted_cpuload(cpu); - ns->power += power_of(cpu); + ns->compute_capacity += capacity_of(cpu); cpus++; } @@ -1056,15 +1056,16 @@ static void update_numa_stats(struct numa_stats *ns, int nid) * the @ns structure is NULL'ed and task_numa_compare() will * not find this node attractive. * - * We'll either bail at !has_capacity, or we'll detect a huge imbalance - * and bail there. + * We'll either bail at !has_free_capacity, or we'll detect a huge + * imbalance and bail there. */ if (!cpus) return; - ns->load = (ns->load * SCHED_POWER_SCALE) / ns->power; - ns->capacity = DIV_ROUND_CLOSEST(ns->power, SCHED_POWER_SCALE); - ns->has_capacity = (ns->nr_running < ns->capacity); + ns->load = (ns->load * SCHED_CAPACITY_SCALE) / ns->compute_capacity; + ns->task_capacity = + DIV_ROUND_CLOSEST(ns->compute_capacity, SCHED_CAPACITY_SCALE); + ns->has_free_capacity = (ns->nr_running < ns->task_capacity); } struct task_numa_env { @@ -1195,8 +1196,8 @@ static void task_numa_compare(struct task_numa_env *env, if (!cur) { /* Is there capacity at our destination? */ - if (env->src_stats.has_capacity && - !env->dst_stats.has_capacity) + if (env->src_stats.has_free_capacity && + !env->dst_stats.has_free_capacity) goto unlock; goto balance; @@ -1213,7 +1214,7 @@ balance: orig_dst_load = env->dst_stats.load; orig_src_load = env->src_stats.load; - /* XXX missing power terms */ + /* XXX missing capacity terms */ load = task_h_load(env->p); dst_load = orig_dst_load + load; src_load = orig_src_load - load; @@ -1301,8 +1302,8 @@ static int task_numa_migrate(struct task_struct *p) groupimp = group_weight(p, env.dst_nid) - groupweight; update_numa_stats(&env.dst_stats, env.dst_nid); - /* If the preferred nid has capacity, try to use it. */ - if (env.dst_stats.has_capacity) + /* If the preferred nid has free capacity, try to use it. */ + if (env.dst_stats.has_free_capacity) task_numa_find_cpu(&env, taskimp, groupimp); /* No space available on the preferred nid. Look elsewhere. */ @@ -3225,10 +3226,12 @@ static void expire_cfs_rq_runtime(struct cfs_rq *cfs_rq) * has not truly expired. * * Fortunately we can check determine whether this the case by checking - * whether the global deadline has advanced. + * whether the global deadline has advanced. It is valid to compare + * cfs_b->runtime_expires without any locks since we only care about + * exact equality, so a partial write will still work. */ - if ((s64)(cfs_rq->runtime_expires - cfs_b->runtime_expires) >= 0) { + if (cfs_rq->runtime_expires != cfs_b->runtime_expires) { /* extend local deadline, drift is bounded above by 2 ticks */ cfs_rq->runtime_expires += TICK_NSEC; } else { @@ -3457,21 +3460,21 @@ next: static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) { u64 runtime, runtime_expires; - int idle = 1, throttled; + int throttled; - raw_spin_lock(&cfs_b->lock); /* no need to continue the timer with no bandwidth constraint */ if (cfs_b->quota == RUNTIME_INF) - goto out_unlock; + goto out_deactivate; throttled = !list_empty(&cfs_b->throttled_cfs_rq); - /* idle depends on !throttled (for the case of a large deficit) */ - idle = cfs_b->idle && !throttled; cfs_b->nr_periods += overrun; - /* if we're going inactive then everything else can be deferred */ - if (idle) - goto out_unlock; + /* + * idle depends on !throttled (for the case of a large deficit), and if + * we're going inactive then everything else can be deferred + */ + if (cfs_b->idle && !throttled) + goto out_deactivate; /* * if we have relooped after returning idle once, we need to update our @@ -3485,7 +3488,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) if (!throttled) { /* mark as potentially idle for the upcoming period */ cfs_b->idle = 1; - goto out_unlock; + return 0; } /* account preceding periods in which throttling occurred */ @@ -3525,12 +3528,12 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) * timer to remain active while there are any throttled entities.) */ cfs_b->idle = 0; -out_unlock: - if (idle) - cfs_b->timer_active = 0; - raw_spin_unlock(&cfs_b->lock); - return idle; + return 0; + +out_deactivate: + cfs_b->timer_active = 0; + return 1; } /* a cfs_rq won't donate quota below this amount */ @@ -3707,6 +3710,7 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) int overrun; int idle = 0; + raw_spin_lock(&cfs_b->lock); for (;;) { now = hrtimer_cb_get_time(timer); overrun = hrtimer_forward(timer, now, cfs_b->period); @@ -3716,6 +3720,7 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) idle = do_sched_cfs_period_timer(cfs_b, overrun); } + raw_spin_unlock(&cfs_b->lock); return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; } @@ -3775,8 +3780,6 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq) struct cfs_rq *cfs_rq; for_each_leaf_cfs_rq(rq, cfs_rq) { - struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); - if (!cfs_rq->runtime_enabled) continue; @@ -3784,7 +3787,7 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq) * clock_task is not advancing so we just need to make sure * there's some valid quota amount */ - cfs_rq->runtime_remaining = cfs_b->quota; + cfs_rq->runtime_remaining = 1; if (cfs_rq_throttled(cfs_rq)) unthrottle_cfs_rq(cfs_rq); } @@ -4041,9 +4044,9 @@ static unsigned long target_load(int cpu, int type) return max(rq->cpu_load[type-1], total); } -static unsigned long power_of(int cpu) +static unsigned long capacity_of(int cpu) { - return cpu_rq(cpu)->cpu_power; + return cpu_rq(cpu)->cpu_capacity; } static unsigned long cpu_avg_load_per_task(int cpu) @@ -4065,7 +4068,7 @@ static void record_wakee(struct task_struct *p) * about the boundary, really active task won't care * about the loss. */ - if (jiffies > current->wakee_flip_decay_ts + HZ) { + if (time_after(jiffies, current->wakee_flip_decay_ts + HZ)) { current->wakee_flips >>= 1; current->wakee_flip_decay_ts = jiffies; } @@ -4286,12 +4289,12 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) s64 this_eff_load, prev_eff_load; this_eff_load = 100; - this_eff_load *= power_of(prev_cpu); + this_eff_load *= capacity_of(prev_cpu); this_eff_load *= this_load + effective_load(tg, this_cpu, weight, weight); prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2; - prev_eff_load *= power_of(this_cpu); + prev_eff_load *= capacity_of(this_cpu); prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight); balanced = this_eff_load <= prev_eff_load; @@ -4367,8 +4370,8 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, avg_load += load; } - /* Adjust by relative CPU power of the group */ - avg_load = (avg_load * SCHED_POWER_SCALE) / group->sgp->power; + /* Adjust by relative CPU capacity of the group */ + avg_load = (avg_load * SCHED_CAPACITY_SCALE) / group->sgc->capacity; if (local_group) { this_load = avg_load; @@ -4948,14 +4951,14 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp * * W'_i,n = (2^n - 1) / 2^n * W_i,n + 1 / 2^n * W_i,0 (3) * - * P_i is the cpu power (or compute capacity) of cpu i, typically it is the + * C_i is the compute capacity of cpu i, typically it is the * fraction of 'recent' time available for SCHED_OTHER task execution. But it * can also include other factors [XXX]. * * To achieve this balance we define a measure of imbalance which follows * directly from (1): * - * imb_i,j = max{ avg(W/P), W_i/P_i } - min{ avg(W/P), W_j/P_j } (4) + * imb_i,j = max{ avg(W/C), W_i/C_i } - min{ avg(W/C), W_j/C_j } (4) * * We them move tasks around to minimize the imbalance. In the continuous * function space it is obvious this converges, in the discrete case we get @@ -5530,13 +5533,13 @@ struct sg_lb_stats { unsigned long group_load; /* Total load over the CPUs of the group */ unsigned long sum_weighted_load; /* Weighted load of group's tasks */ unsigned long load_per_task; - unsigned long group_power; + unsigned long group_capacity; unsigned int sum_nr_running; /* Nr tasks running in the group */ - unsigned int group_capacity; + unsigned int group_capacity_factor; unsigned int idle_cpus; unsigned int group_weight; int group_imb; /* Is there an imbalance in the group ? */ - int group_has_capacity; /* Is there extra capacity in the group? */ + int group_has_free_capacity; #ifdef CONFIG_NUMA_BALANCING unsigned int nr_numa_running; unsigned int nr_preferred_running; @@ -5551,7 +5554,7 @@ struct sd_lb_stats { struct sched_group *busiest; /* Busiest group in this sd */ struct sched_group *local; /* Local group in this sd */ unsigned long total_load; /* Total load of all groups in sd */ - unsigned long total_pwr; /* Total power of all groups in sd */ + unsigned long total_capacity; /* Total capacity of all groups in sd */ unsigned long avg_load; /* Average load across all groups in sd */ struct sg_lb_stats busiest_stat;/* Statistics of the busiest group */ @@ -5570,7 +5573,7 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds) .busiest = NULL, .local = NULL, .total_load = 0UL, - .total_pwr = 0UL, + .total_capacity = 0UL, .busiest_stat = { .avg_load = 0UL, }, @@ -5605,17 +5608,17 @@ static inline int get_sd_load_idx(struct sched_domain *sd, return load_idx; } -static unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu) +static unsigned long default_scale_capacity(struct sched_domain *sd, int cpu) { - return SCHED_POWER_SCALE; + return SCHED_CAPACITY_SCALE; } -unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu) +unsigned long __weak arch_scale_freq_capacity(struct sched_domain *sd, int cpu) { - return default_scale_freq_power(sd, cpu); + return default_scale_capacity(sd, cpu); } -static unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) +static unsigned long default_scale_smt_capacity(struct sched_domain *sd, int cpu) { unsigned long weight = sd->span_weight; unsigned long smt_gain = sd->smt_gain; @@ -5625,12 +5628,12 @@ static unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) return smt_gain; } -unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) +unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu) { - return default_scale_smt_power(sd, cpu); + return default_scale_smt_capacity(sd, cpu); } -static unsigned long scale_rt_power(int cpu) +static unsigned long scale_rt_capacity(int cpu) { struct rq *rq = cpu_rq(cpu); u64 total, available, age_stamp, avg; @@ -5650,71 +5653,71 @@ static unsigned long scale_rt_power(int cpu) total = sched_avg_period() + delta; if (unlikely(total < avg)) { - /* Ensures that power won't end up being negative */ + /* Ensures that capacity won't end up being negative */ available = 0; } else { available = total - avg; } - if (unlikely((s64)total < SCHED_POWER_SCALE)) - total = SCHED_POWER_SCALE; + if (unlikely((s64)total < SCHED_CAPACITY_SCALE)) + total = SCHED_CAPACITY_SCALE; - total >>= SCHED_POWER_SHIFT; + total >>= SCHED_CAPACITY_SHIFT; return div_u64(available, total); } -static void update_cpu_power(struct sched_domain *sd, int cpu) +static void update_cpu_capacity(struct sched_domain *sd, int cpu) { unsigned long weight = sd->span_weight; - unsigned long power = SCHED_POWER_SCALE; + unsigned long capacity = SCHED_CAPACITY_SCALE; struct sched_group *sdg = sd->groups; - if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { - if (sched_feat(ARCH_POWER)) - power *= arch_scale_smt_power(sd, cpu); + if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { + if (sched_feat(ARCH_CAPACITY)) + capacity *= arch_scale_smt_capacity(sd, cpu); else - power *= default_scale_smt_power(sd, cpu); + capacity *= default_scale_smt_capacity(sd, cpu); - power >>= SCHED_POWER_SHIFT; + capacity >>= SCHED_CAPACITY_SHIFT; } - sdg->sgp->power_orig = power; + sdg->sgc->capacity_orig = capacity; - if (sched_feat(ARCH_POWER)) - power *= arch_scale_freq_power(sd, cpu); + if (sched_feat(ARCH_CAPACITY)) + capacity *= arch_scale_freq_capacity(sd, cpu); else - power *= default_scale_freq_power(sd, cpu); + capacity *= default_scale_capacity(sd, cpu); - power >>= SCHED_POWER_SHIFT; + capacity >>= SCHED_CAPACITY_SHIFT; - power *= scale_rt_power(cpu); - power >>= SCHED_POWER_SHIFT; + capacity *= scale_rt_capacity(cpu); + capacity >>= SCHED_CAPACITY_SHIFT; - if (!power) - power = 1; + if (!capacity) + capacity = 1; - cpu_rq(cpu)->cpu_power = power; - sdg->sgp->power = power; + cpu_rq(cpu)->cpu_capacity = capacity; + sdg->sgc->capacity = capacity; } -void update_group_power(struct sched_domain *sd, int cpu) +void update_group_capacity(struct sched_domain *sd, int cpu) { struct sched_domain *child = sd->child; struct sched_group *group, *sdg = sd->groups; - unsigned long power, power_orig; + unsigned long capacity, capacity_orig; unsigned long interval; interval = msecs_to_jiffies(sd->balance_interval); interval = clamp(interval, 1UL, max_load_balance_interval); - sdg->sgp->next_update = jiffies + interval; + sdg->sgc->next_update = jiffies + interval; if (!child) { - update_cpu_power(sd, cpu); + update_cpu_capacity(sd, cpu); return; } - power_orig = power = 0; + capacity_orig = capacity = 0; if (child->flags & SD_OVERLAP) { /* @@ -5723,31 +5726,31 @@ void update_group_power(struct sched_domain *sd, int cpu) */ for_each_cpu(cpu, sched_group_cpus(sdg)) { - struct sched_group_power *sgp; + struct sched_group_capacity *sgc; struct rq *rq = cpu_rq(cpu); /* - * build_sched_domains() -> init_sched_groups_power() + * build_sched_domains() -> init_sched_groups_capacity() * gets here before we've attached the domains to the * runqueues. * - * Use power_of(), which is set irrespective of domains - * in update_cpu_power(). + * Use capacity_of(), which is set irrespective of domains + * in update_cpu_capacity(). * - * This avoids power/power_orig from being 0 and + * This avoids capacity/capacity_orig from being 0 and * causing divide-by-zero issues on boot. * - * Runtime updates will correct power_orig. + * Runtime updates will correct capacity_orig. */ if (unlikely(!rq->sd)) { - power_orig += power_of(cpu); - power += power_of(cpu); + capacity_orig += capacity_of(cpu); + capacity += capacity_of(cpu); continue; } - sgp = rq->sd->groups->sgp; - power_orig += sgp->power_orig; - power += sgp->power; + sgc = rq->sd->groups->sgc; + capacity_orig += sgc->capacity_orig; + capacity += sgc->capacity; } } else { /* @@ -5757,14 +5760,14 @@ void update_group_power(struct sched_domain *sd, int cpu) group = child->groups; do { - power_orig += group->sgp->power_orig; - power += group->sgp->power; + capacity_orig += group->sgc->capacity_orig; + capacity += group->sgc->capacity; group = group->next; } while (group != child->groups); } - sdg->sgp->power_orig = power_orig; - sdg->sgp->power = power; + sdg->sgc->capacity_orig = capacity_orig; + sdg->sgc->capacity = capacity; } /* @@ -5778,15 +5781,15 @@ static inline int fix_small_capacity(struct sched_domain *sd, struct sched_group *group) { /* - * Only siblings can have significantly less than SCHED_POWER_SCALE + * Only siblings can have significantly less than SCHED_CAPACITY_SCALE */ - if (!(sd->flags & SD_SHARE_CPUPOWER)) + if (!(sd->flags & SD_SHARE_CPUCAPACITY)) return 0; /* - * If ~90% of the cpu_power is still there, we're good. + * If ~90% of the cpu_capacity is still there, we're good. */ - if (group->sgp->power * 32 > group->sgp->power_orig * 29) + if (group->sgc->capacity * 32 > group->sgc->capacity_orig * 29) return 1; return 0; @@ -5823,34 +5826,35 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group) static inline int sg_imbalanced(struct sched_group *group) { - return group->sgp->imbalance; + return group->sgc->imbalance; } /* - * Compute the group capacity. + * Compute the group capacity factor. * - * Avoid the issue where N*frac(smt_power) >= 1 creates 'phantom' cores by + * Avoid the issue where N*frac(smt_capacity) >= 1 creates 'phantom' cores by * first dividing out the smt factor and computing the actual number of cores - * and limit power unit capacity with that. + * and limit unit capacity with that. */ -static inline int sg_capacity(struct lb_env *env, struct sched_group *group) +static inline int sg_capacity_factor(struct lb_env *env, struct sched_group *group) { - unsigned int capacity, smt, cpus; - unsigned int power, power_orig; + unsigned int capacity_factor, smt, cpus; + unsigned int capacity, capacity_orig; - power = group->sgp->power; - power_orig = group->sgp->power_orig; + capacity = group->sgc->capacity; + capacity_orig = group->sgc->capacity_orig; cpus = group->group_weight; - /* smt := ceil(cpus / power), assumes: 1 < smt_power < 2 */ - smt = DIV_ROUND_UP(SCHED_POWER_SCALE * cpus, power_orig); - capacity = cpus / smt; /* cores */ + /* smt := ceil(cpus / capacity), assumes: 1 < smt_capacity < 2 */ + smt = DIV_ROUND_UP(SCHED_CAPACITY_SCALE * cpus, capacity_orig); + capacity_factor = cpus / smt; /* cores */ - capacity = min_t(unsigned, capacity, DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE)); - if (!capacity) - capacity = fix_small_capacity(env->sd, group); + capacity_factor = min_t(unsigned, + capacity_factor, DIV_ROUND_CLOSEST(capacity, SCHED_CAPACITY_SCALE)); + if (!capacity_factor) + capacity_factor = fix_small_capacity(env->sd, group); - return capacity; + return capacity_factor; } /** @@ -5890,9 +5894,9 @@ static inline void update_sg_lb_stats(struct lb_env *env, sgs->idle_cpus++; } - /* Adjust by relative CPU power of the group */ - sgs->group_power = group->sgp->power; - sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / sgs->group_power; + /* Adjust by relative CPU capacity of the group */ + sgs->group_capacity = group->sgc->capacity; + sgs->avg_load = (sgs->group_load*SCHED_CAPACITY_SCALE) / sgs->group_capacity; if (sgs->sum_nr_running) sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running; @@ -5900,10 +5904,10 @@ static inline void update_sg_lb_stats(struct lb_env *env, sgs->group_weight = group->group_weight; sgs->group_imb = sg_imbalanced(group); - sgs->group_capacity = sg_capacity(env, group); + sgs->group_capacity_factor = sg_capacity_factor(env, group); - if (sgs->group_capacity > sgs->sum_nr_running) - sgs->group_has_capacity = 1; + if (sgs->group_capacity_factor > sgs->sum_nr_running) + sgs->group_has_free_capacity = 1; } /** @@ -5927,7 +5931,7 @@ static bool update_sd_pick_busiest(struct lb_env *env, if (sgs->avg_load <= sds->busiest_stat.avg_load) return false; - if (sgs->sum_nr_running > sgs->group_capacity) + if (sgs->sum_nr_running > sgs->group_capacity_factor) return true; if (sgs->group_imb) @@ -6007,8 +6011,8 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd sgs = &sds->local_stat; if (env->idle != CPU_NEWLY_IDLE || - time_after_eq(jiffies, sg->sgp->next_update)) - update_group_power(env->sd, env->dst_cpu); + time_after_eq(jiffies, sg->sgc->next_update)) + update_group_capacity(env->sd, env->dst_cpu); } update_sg_lb_stats(env, sg, load_idx, local_group, sgs); @@ -6018,17 +6022,17 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd /* * In case the child domain prefers tasks go to siblings - * first, lower the sg capacity to one so that we'll try + * first, lower the sg capacity factor to one so that we'll try * and move all the excess tasks away. We lower the capacity * of a group only if the local group has the capacity to fit - * these excess tasks, i.e. nr_running < group_capacity. The + * these excess tasks, i.e. nr_running < group_capacity_factor. The * extra check prevents the case where you always pull from the * heaviest group when it is already under-utilized (possible * with a large weight task outweighs the tasks on the system). */ if (prefer_sibling && sds->local && - sds->local_stat.group_has_capacity) - sgs->group_capacity = min(sgs->group_capacity, 1U); + sds->local_stat.group_has_free_capacity) + sgs->group_capacity_factor = min(sgs->group_capacity_factor, 1U); if (update_sd_pick_busiest(env, sds, sg, sgs)) { sds->busiest = sg; @@ -6038,7 +6042,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd next_group: /* Now, start updating sd_lb_stats */ sds->total_load += sgs->group_load; - sds->total_pwr += sgs->group_power; + sds->total_capacity += sgs->group_capacity; sg = sg->next; } while (sg != env->sd->groups); @@ -6085,8 +6089,8 @@ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) return 0; env->imbalance = DIV_ROUND_CLOSEST( - sds->busiest_stat.avg_load * sds->busiest_stat.group_power, - SCHED_POWER_SCALE); + sds->busiest_stat.avg_load * sds->busiest_stat.group_capacity, + SCHED_CAPACITY_SCALE); return 1; } @@ -6101,7 +6105,7 @@ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) static inline void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) { - unsigned long tmp, pwr_now = 0, pwr_move = 0; + unsigned long tmp, capa_now = 0, capa_move = 0; unsigned int imbn = 2; unsigned long scaled_busy_load_per_task; struct sg_lb_stats *local, *busiest; @@ -6115,8 +6119,8 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) imbn = 1; scaled_busy_load_per_task = - (busiest->load_per_task * SCHED_POWER_SCALE) / - busiest->group_power; + (busiest->load_per_task * SCHED_CAPACITY_SCALE) / + busiest->group_capacity; if (busiest->avg_load + scaled_busy_load_per_task >= local->avg_load + (scaled_busy_load_per_task * imbn)) { @@ -6126,38 +6130,38 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) /* * OK, we don't have enough imbalance to justify moving tasks, - * however we may be able to increase total CPU power used by + * however we may be able to increase total CPU capacity used by * moving them. */ - pwr_now += busiest->group_power * + capa_now += busiest->group_capacity * min(busiest->load_per_task, busiest->avg_load); - pwr_now += local->group_power * + capa_now += local->group_capacity * min(local->load_per_task, local->avg_load); - pwr_now /= SCHED_POWER_SCALE; + capa_now /= SCHED_CAPACITY_SCALE; /* Amount of load we'd subtract */ if (busiest->avg_load > scaled_busy_load_per_task) { - pwr_move += busiest->group_power * + capa_move += busiest->group_capacity * min(busiest->load_per_task, busiest->avg_load - scaled_busy_load_per_task); } /* Amount of load we'd add */ - if (busiest->avg_load * busiest->group_power < - busiest->load_per_task * SCHED_POWER_SCALE) { - tmp = (busiest->avg_load * busiest->group_power) / - local->group_power; + if (busiest->avg_load * busiest->group_capacity < + busiest->load_per_task * SCHED_CAPACITY_SCALE) { + tmp = (busiest->avg_load * busiest->group_capacity) / + local->group_capacity; } else { - tmp = (busiest->load_per_task * SCHED_POWER_SCALE) / - local->group_power; + tmp = (busiest->load_per_task * SCHED_CAPACITY_SCALE) / + local->group_capacity; } - pwr_move += local->group_power * + capa_move += local->group_capacity * min(local->load_per_task, local->avg_load + tmp); - pwr_move /= SCHED_POWER_SCALE; + capa_move /= SCHED_CAPACITY_SCALE; /* Move if we gain throughput */ - if (pwr_move > pwr_now) + if (capa_move > capa_now) env->imbalance = busiest->load_per_task; } @@ -6187,7 +6191,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s /* * In the presence of smp nice balancing, certain scenarios can have * max load less than avg load(as we skip the groups at or below - * its cpu_power, while calculating max_load..) + * its cpu_capacity, while calculating max_load..) */ if (busiest->avg_load <= sds->avg_load || local->avg_load >= sds->avg_load) { @@ -6202,10 +6206,10 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s * have to drop below capacity to reach cpu-load equilibrium. */ load_above_capacity = - (busiest->sum_nr_running - busiest->group_capacity); + (busiest->sum_nr_running - busiest->group_capacity_factor); - load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE); - load_above_capacity /= busiest->group_power; + load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_CAPACITY_SCALE); + load_above_capacity /= busiest->group_capacity; } /* @@ -6220,9 +6224,9 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s /* How much load to actually move to equalise the imbalance */ env->imbalance = min( - max_pull * busiest->group_power, - (sds->avg_load - local->avg_load) * local->group_power - ) / SCHED_POWER_SCALE; + max_pull * busiest->group_capacity, + (sds->avg_load - local->avg_load) * local->group_capacity + ) / SCHED_CAPACITY_SCALE; /* * if *imbalance is less than the average load per runnable task @@ -6276,7 +6280,8 @@ static struct sched_group *find_busiest_group(struct lb_env *env) if (!sds.busiest || busiest->sum_nr_running == 0) goto out_balanced; - sds.avg_load = (SCHED_POWER_SCALE * sds.total_load) / sds.total_pwr; + sds.avg_load = (SCHED_CAPACITY_SCALE * sds.total_load) + / sds.total_capacity; /* * If the busiest group is imbalanced the below checks don't @@ -6287,8 +6292,8 @@ static struct sched_group *find_busiest_group(struct lb_env *env) goto force_balance; /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */ - if (env->idle == CPU_NEWLY_IDLE && local->group_has_capacity && - !busiest->group_has_capacity) + if (env->idle == CPU_NEWLY_IDLE && local->group_has_free_capacity && + !busiest->group_has_free_capacity) goto force_balance; /* @@ -6342,11 +6347,11 @@ static struct rq *find_busiest_queue(struct lb_env *env, struct sched_group *group) { struct rq *busiest = NULL, *rq; - unsigned long busiest_load = 0, busiest_power = 1; + unsigned long busiest_load = 0, busiest_capacity = 1; int i; for_each_cpu_and(i, sched_group_cpus(group), env->cpus) { - unsigned long power, capacity, wl; + unsigned long capacity, capacity_factor, wl; enum fbq_type rt; rq = cpu_rq(i); @@ -6374,34 +6379,34 @@ static struct rq *find_busiest_queue(struct lb_env *env, if (rt > env->fbq_type) continue; - power = power_of(i); - capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE); - if (!capacity) - capacity = fix_small_capacity(env->sd, group); + capacity = capacity_of(i); + capacity_factor = DIV_ROUND_CLOSEST(capacity, SCHED_CAPACITY_SCALE); + if (!capacity_factor) + capacity_factor = fix_small_capacity(env->sd, group); wl = weighted_cpuload(i); /* * When comparing with imbalance, use weighted_cpuload() - * which is not scaled with the cpu power. + * which is not scaled with the cpu capacity. */ - if (capacity && rq->nr_running == 1 && wl > env->imbalance) + if (capacity_factor && rq->nr_running == 1 && wl > env->imbalance) continue; /* * For the load comparisons with the other cpu's, consider - * the weighted_cpuload() scaled with the cpu power, so that - * the load can be moved away from the cpu that is potentially - * running at a lower capacity. + * the weighted_cpuload() scaled with the cpu capacity, so + * that the load can be moved away from the cpu that is + * potentially running at a lower capacity. * - * Thus we're looking for max(wl_i / power_i), crosswise + * Thus we're looking for max(wl_i / capacity_i), crosswise * multiplication to rid ourselves of the division works out - * to: wl_i * power_j > wl_j * power_i; where j is our - * previous maximum. + * to: wl_i * capacity_j > wl_j * capacity_i; where j is + * our previous maximum. */ - if (wl * busiest_power > busiest_load * power) { + if (wl * busiest_capacity > busiest_load * capacity) { busiest_load = wl; - busiest_power = power; + busiest_capacity = capacity; busiest = rq; } } @@ -6609,7 +6614,7 @@ more_balance: * We failed to reach balance because of affinity. */ if (sd_parent) { - int *group_imbalance = &sd_parent->groups->sgp->imbalance; + int *group_imbalance = &sd_parent->groups->sgc->imbalance; if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) { *group_imbalance = 1; @@ -6996,7 +7001,7 @@ static inline void set_cpu_sd_state_busy(void) goto unlock; sd->nohz_idle = 0; - atomic_inc(&sd->groups->sgp->nr_busy_cpus); + atomic_inc(&sd->groups->sgc->nr_busy_cpus); unlock: rcu_read_unlock(); } @@ -7013,7 +7018,7 @@ void set_cpu_sd_state_idle(void) goto unlock; sd->nohz_idle = 1; - atomic_dec(&sd->groups->sgp->nr_busy_cpus); + atomic_dec(&sd->groups->sgc->nr_busy_cpus); unlock: rcu_read_unlock(); } @@ -7192,12 +7197,17 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) rq = cpu_rq(balance_cpu); - raw_spin_lock_irq(&rq->lock); - update_rq_clock(rq); - update_idle_cpu_load(rq); - raw_spin_unlock_irq(&rq->lock); - - rebalance_domains(rq, CPU_IDLE); + /* + * If time for next balance is due, + * do the balance. + */ + if (time_after_eq(jiffies, rq->next_balance)) { + raw_spin_lock_irq(&rq->lock); + update_rq_clock(rq); + update_idle_cpu_load(rq); + raw_spin_unlock_irq(&rq->lock); + rebalance_domains(rq, CPU_IDLE); + } if (time_after(this_rq->next_balance, rq->next_balance)) this_rq->next_balance = rq->next_balance; @@ -7212,7 +7222,7 @@ end: * of an idle cpu is the system. * - This rq has more than one task. * - At any scheduler domain level, this cpu's scheduler group has multiple - * busy cpu's exceeding the group's power. + * busy cpu's exceeding the group's capacity. * - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler * domain span are idle. */ @@ -7220,7 +7230,7 @@ static inline int nohz_kick_needed(struct rq *rq) { unsigned long now = jiffies; struct sched_domain *sd; - struct sched_group_power *sgp; + struct sched_group_capacity *sgc; int nr_busy, cpu = rq->cpu; if (unlikely(rq->idle_balance)) @@ -7250,8 +7260,8 @@ static inline int nohz_kick_needed(struct rq *rq) sd = rcu_dereference(per_cpu(sd_busy, cpu)); if (sd) { - sgp = sd->groups->sgp; - nr_busy = atomic_read(&sgp->nr_busy_cpus); + sgc = sd->groups->sgc; + nr_busy = atomic_read(&sgc->nr_busy_cpus); if (nr_busy > 1) goto need_kick_unlock; diff --git a/kernel/sched/features.h b/kernel/sched/features.h index 5716929a2e3a..90284d117fe6 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -37,18 +37,18 @@ SCHED_FEAT(CACHE_HOT_BUDDY, true) SCHED_FEAT(WAKEUP_PREEMPTION, true) /* - * Use arch dependent cpu power functions + * Use arch dependent cpu capacity functions */ -SCHED_FEAT(ARCH_POWER, true) +SCHED_FEAT(ARCH_CAPACITY, true) SCHED_FEAT(HRTICK, false) SCHED_FEAT(DOUBLE_TICK, false) SCHED_FEAT(LB_BIAS, true) /* - * Decrement CPU power based on time not spent running tasks + * Decrement CPU capacity based on time not spent running tasks */ -SCHED_FEAT(NONTASK_POWER, true) +SCHED_FEAT(NONTASK_CAPACITY, true) /* * Queue remote wakeups on the target CPU and process them diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 25b9423abce9..cf009fb0bc25 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -12,6 +12,8 @@ #include <trace/events/power.h> +#include "sched.h" + static int __read_mostly cpu_idle_force_poll; void cpu_idle_poll_ctrl(bool enable) @@ -67,6 +69,10 @@ void __weak arch_cpu_idle(void) * cpuidle_idle_call - the main idle function * * NOTE: no locks or semaphores should be used here + * + * On archs that support TIF_POLLING_NRFLAG, is called with polling + * set, and it returns with polling set. If it ever stops polling, it + * must clear the polling bit. */ static void cpuidle_idle_call(void) { @@ -175,10 +181,22 @@ exit_idle: /* * Generic idle loop implementation + * + * Called with polling cleared. */ static void cpu_idle_loop(void) { while (1) { + /* + * If the arch has a polling bit, we maintain an invariant: + * + * Our polling bit is clear if we're not scheduled (i.e. if + * rq->curr != rq->idle). This means that, if rq->idle has + * the polling bit set, then setting need_resched is + * guaranteed to cause the cpu to reschedule. + */ + + __current_set_polling(); tick_nohz_idle_enter(); while (!need_resched()) { @@ -218,6 +236,17 @@ static void cpu_idle_loop(void) */ preempt_set_need_resched(); tick_nohz_idle_exit(); + __current_clr_polling(); + + /* + * We promise to call sched_ttwu_pending and reschedule + * if need_resched is set while polling is set. That + * means that clearing polling needs to be visible + * before doing these things. + */ + smp_mb__after_atomic(); + + sched_ttwu_pending(); schedule_preempt_disabled(); } } @@ -239,7 +268,6 @@ void cpu_startup_entry(enum cpuhp_state state) */ boot_init_stack_canary(); #endif - __current_set_polling(); arch_cpu_idle_prepare(); cpu_idle_loop(); } diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index b3512f1afce9..a49083192c64 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -918,7 +918,6 @@ static void update_curr_rt(struct rq *rq) { struct task_struct *curr = rq->curr; struct sched_rt_entity *rt_se = &curr->rt; - struct rt_rq *rt_rq = rt_rq_of_se(rt_se); u64 delta_exec; if (curr->sched_class != &rt_sched_class) @@ -943,7 +942,7 @@ static void update_curr_rt(struct rq *rq) return; for_each_sched_rt_entity(rt_se) { - rt_rq = rt_rq_of_se(rt_se); + struct rt_rq *rt_rq = rt_rq_of_se(rt_se); if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { raw_spin_lock(&rt_rq->rt_runtime_lock); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e47679b04d16..31cc02ebc54e 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -567,7 +567,7 @@ struct rq { struct root_domain *rd; struct sched_domain *sd; - unsigned long cpu_power; + unsigned long cpu_capacity; unsigned char idle_balance; /* For active balancing */ @@ -670,6 +670,8 @@ extern int migrate_swap(struct task_struct *, struct task_struct *); #ifdef CONFIG_SMP +extern void sched_ttwu_pending(void); + #define rcu_dereference_check_sched_domain(p) \ rcu_dereference_check((p), \ lockdep_is_held(&sched_domains_mutex)) @@ -728,15 +730,15 @@ DECLARE_PER_CPU(struct sched_domain *, sd_numa); DECLARE_PER_CPU(struct sched_domain *, sd_busy); DECLARE_PER_CPU(struct sched_domain *, sd_asym); -struct sched_group_power { +struct sched_group_capacity { atomic_t ref; /* - * CPU power of this group, SCHED_LOAD_SCALE being max power for a - * single CPU. + * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity + * for a single CPU. */ - unsigned int power, power_orig; + unsigned int capacity, capacity_orig; unsigned long next_update; - int imbalance; /* XXX unrelated to power but shared group state */ + int imbalance; /* XXX unrelated to capacity but shared group state */ /* * Number of busy cpus in this group. */ @@ -750,7 +752,7 @@ struct sched_group { atomic_t ref; unsigned int group_weight; - struct sched_group_power *sgp; + struct sched_group_capacity *sgc; /* * The CPUs this group covers. @@ -773,7 +775,7 @@ static inline struct cpumask *sched_group_cpus(struct sched_group *sg) */ static inline struct cpumask *sched_group_mask(struct sched_group *sg) { - return to_cpumask(sg->sgp->cpumask); + return to_cpumask(sg->sgc->cpumask); } /** @@ -787,6 +789,10 @@ static inline unsigned int group_first_cpu(struct sched_group *group) extern int group_balance_cpu(struct sched_group *sg); +#else + +static inline void sched_ttwu_pending(void) { } + #endif /* CONFIG_SMP */ #include "stats.h" @@ -1167,7 +1173,7 @@ extern const struct sched_class idle_sched_class; #ifdef CONFIG_SMP -extern void update_group_power(struct sched_domain *sd, int cpu); +extern void update_group_capacity(struct sched_domain *sd, int cpu); extern void trigger_load_balance(struct rq *rq); diff --git a/kernel/seccomp.c b/kernel/seccomp.c index f6d76bebe69f..301bbc24739c 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -54,8 +54,7 @@ struct seccomp_filter { atomic_t usage; struct seccomp_filter *prev; - unsigned short len; /* Instruction count */ - struct sock_filter_int insnsi[]; + struct sk_filter *prog; }; /* Limit any path through the tree to 256KB worth of instructions. */ @@ -104,60 +103,59 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen) u32 k = ftest->k; switch (code) { - case BPF_S_LD_W_ABS: + case BPF_LD | BPF_W | BPF_ABS: ftest->code = BPF_LDX | BPF_W | BPF_ABS; /* 32-bit aligned and not out of bounds. */ if (k >= sizeof(struct seccomp_data) || k & 3) return -EINVAL; continue; - case BPF_S_LD_W_LEN: + case BPF_LD | BPF_W | BPF_LEN: ftest->code = BPF_LD | BPF_IMM; ftest->k = sizeof(struct seccomp_data); continue; - case BPF_S_LDX_W_LEN: + case BPF_LDX | BPF_W | BPF_LEN: ftest->code = BPF_LDX | BPF_IMM; ftest->k = sizeof(struct seccomp_data); continue; /* Explicitly include allowed calls. */ - case BPF_S_RET_K: - case BPF_S_RET_A: - case BPF_S_ALU_ADD_K: - case BPF_S_ALU_ADD_X: - case BPF_S_ALU_SUB_K: - case BPF_S_ALU_SUB_X: - case BPF_S_ALU_MUL_K: - case BPF_S_ALU_MUL_X: - case BPF_S_ALU_DIV_X: - case BPF_S_ALU_AND_K: - case BPF_S_ALU_AND_X: - case BPF_S_ALU_OR_K: - case BPF_S_ALU_OR_X: - case BPF_S_ALU_XOR_K: - case BPF_S_ALU_XOR_X: - case BPF_S_ALU_LSH_K: - case BPF_S_ALU_LSH_X: - case BPF_S_ALU_RSH_K: - case BPF_S_ALU_RSH_X: - case BPF_S_ALU_NEG: - case BPF_S_LD_IMM: - case BPF_S_LDX_IMM: - case BPF_S_MISC_TAX: - case BPF_S_MISC_TXA: - case BPF_S_ALU_DIV_K: - case BPF_S_LD_MEM: - case BPF_S_LDX_MEM: - case BPF_S_ST: - case BPF_S_STX: - case BPF_S_JMP_JA: - case BPF_S_JMP_JEQ_K: - case BPF_S_JMP_JEQ_X: - case BPF_S_JMP_JGE_K: - case BPF_S_JMP_JGE_X: - case BPF_S_JMP_JGT_K: - case BPF_S_JMP_JGT_X: - case BPF_S_JMP_JSET_K: - case BPF_S_JMP_JSET_X: - sk_decode_filter(ftest, ftest); + case BPF_RET | BPF_K: + case BPF_RET | BPF_A: + case BPF_ALU | BPF_ADD | BPF_K: + case BPF_ALU | BPF_ADD | BPF_X: + case BPF_ALU | BPF_SUB | BPF_K: + case BPF_ALU | BPF_SUB | BPF_X: + case BPF_ALU | BPF_MUL | BPF_K: + case BPF_ALU | BPF_MUL | BPF_X: + case BPF_ALU | BPF_DIV | BPF_K: + case BPF_ALU | BPF_DIV | BPF_X: + case BPF_ALU | BPF_AND | BPF_K: + case BPF_ALU | BPF_AND | BPF_X: + case BPF_ALU | BPF_OR | BPF_K: + case BPF_ALU | BPF_OR | BPF_X: + case BPF_ALU | BPF_XOR | BPF_K: + case BPF_ALU | BPF_XOR | BPF_X: + case BPF_ALU | BPF_LSH | BPF_K: + case BPF_ALU | BPF_LSH | BPF_X: + case BPF_ALU | BPF_RSH | BPF_K: + case BPF_ALU | BPF_RSH | BPF_X: + case BPF_ALU | BPF_NEG: + case BPF_LD | BPF_IMM: + case BPF_LDX | BPF_IMM: + case BPF_MISC | BPF_TAX: + case BPF_MISC | BPF_TXA: + case BPF_LD | BPF_MEM: + case BPF_LDX | BPF_MEM: + case BPF_ST: + case BPF_STX: + case BPF_JMP | BPF_JA: + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP | BPF_JSET | BPF_X: continue; default: return -EINVAL; @@ -189,7 +187,8 @@ static u32 seccomp_run_filters(int syscall) * value always takes priority (ignoring the DATA). */ for (f = current->seccomp.filter; f; f = f->prev) { - u32 cur_ret = sk_run_filter_int_seccomp(&sd, f->insnsi); + u32 cur_ret = SK_RUN_FILTER(f->prog, (void *)&sd); + if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION)) ret = cur_ret; } @@ -215,7 +214,7 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) return -EINVAL; for (filter = current->seccomp.filter; filter; filter = filter->prev) - total_insns += filter->len + 4; /* include a 4 instr penalty */ + total_insns += filter->prog->len + 4; /* include a 4 instr penalty */ if (total_insns > MAX_INSNS_PER_PATH) return -ENOMEM; @@ -256,19 +255,25 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) /* Allocate a new seccomp_filter */ ret = -ENOMEM; - filter = kzalloc(sizeof(struct seccomp_filter) + - sizeof(struct sock_filter_int) * new_len, + filter = kzalloc(sizeof(struct seccomp_filter), GFP_KERNEL|__GFP_NOWARN); if (!filter) goto free_prog; - ret = sk_convert_filter(fp, fprog->len, filter->insnsi, &new_len); - if (ret) + filter->prog = kzalloc(sk_filter_size(new_len), + GFP_KERNEL|__GFP_NOWARN); + if (!filter->prog) goto free_filter; + + ret = sk_convert_filter(fp, fprog->len, filter->prog->insnsi, &new_len); + if (ret) + goto free_filter_prog; kfree(fp); atomic_set(&filter->usage, 1); - filter->len = new_len; + filter->prog->len = new_len; + + sk_filter_select_runtime(filter->prog); /* * If there is an existing filter, make it the prev and don't drop its @@ -278,6 +283,8 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) current->seccomp.filter = filter; return 0; +free_filter_prog: + kfree(filter->prog); free_filter: kfree(filter); free_prog: @@ -330,6 +337,7 @@ void put_seccomp_filter(struct task_struct *tsk) while (orig && atomic_dec_and_test(&orig->usage)) { struct seccomp_filter *freeme = orig; orig = orig->prev; + sk_filter_free(freeme->prog); kfree(freeme); } } diff --git a/kernel/smp.c b/kernel/smp.c index 306f8180b0d5..80c33f8de14f 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -29,6 +29,8 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data); static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue); +static void flush_smp_call_function_queue(bool warn_cpu_offline); + static int hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) { @@ -51,12 +53,27 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) #ifdef CONFIG_HOTPLUG_CPU case CPU_UP_CANCELED: case CPU_UP_CANCELED_FROZEN: + /* Fall-through to the CPU_DEAD[_FROZEN] case. */ case CPU_DEAD: case CPU_DEAD_FROZEN: free_cpumask_var(cfd->cpumask); free_percpu(cfd->csd); break; + + case CPU_DYING: + case CPU_DYING_FROZEN: + /* + * The IPIs for the smp-call-function callbacks queued by other + * CPUs might arrive late, either due to hardware latencies or + * because this CPU disabled interrupts (inside stop-machine) + * before the IPIs were sent. So flush out any pending callbacks + * explicitly (without waiting for the IPIs to arrive), to + * ensure that the outgoing CPU doesn't go offline with work + * still pending. + */ + flush_smp_call_function_queue(false); + break; #endif }; @@ -177,23 +194,47 @@ static int generic_exec_single(int cpu, struct call_single_data *csd, return 0; } -/* - * Invoked by arch to handle an IPI for call function single. Must be - * called from the arch with interrupts disabled. +/** + * generic_smp_call_function_single_interrupt - Execute SMP IPI callbacks + * + * Invoked by arch to handle an IPI for call function single. + * Must be called with interrupts disabled. */ void generic_smp_call_function_single_interrupt(void) { + flush_smp_call_function_queue(true); +} + +/** + * flush_smp_call_function_queue - Flush pending smp-call-function callbacks + * + * @warn_cpu_offline: If set to 'true', warn if callbacks were queued on an + * offline CPU. Skip this check if set to 'false'. + * + * Flush any pending smp-call-function callbacks queued on this CPU. This is + * invoked by the generic IPI handler, as well as by a CPU about to go offline, + * to ensure that all pending IPI callbacks are run before it goes completely + * offline. + * + * Loop through the call_single_queue and run all the queued callbacks. + * Must be called with interrupts disabled. + */ +static void flush_smp_call_function_queue(bool warn_cpu_offline) +{ + struct llist_head *head; struct llist_node *entry; struct call_single_data *csd, *csd_next; static bool warned; - entry = llist_del_all(&__get_cpu_var(call_single_queue)); + WARN_ON(!irqs_disabled()); + + head = &__get_cpu_var(call_single_queue); + entry = llist_del_all(head); entry = llist_reverse_order(entry); - /* - * Shouldn't receive this interrupt on a cpu that is not yet online. - */ - if (unlikely(!cpu_online(smp_processor_id()) && !warned)) { + /* There shouldn't be any pending callbacks on an offline CPU. */ + if (unlikely(warn_cpu_offline && !cpu_online(smp_processor_id()) && + !warned && !llist_empty(head))) { warned = true; WARN(1, "IPI on offline CPU %d\n", smp_processor_id()); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index db19e3e2aa4b..75b22e22a72c 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -136,7 +136,6 @@ static unsigned long dirty_bytes_min = 2 * PAGE_SIZE; /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ static int maxolduid = 65535; static int minolduid; -static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; static const int cap_last_cap = CAP_LAST_CAP; @@ -152,10 +151,6 @@ static unsigned long hung_task_timeout_max = (LONG_MAX/HZ); #ifdef CONFIG_SPARC #endif -#ifdef CONFIG_SPARC64 -extern int sysctl_tsb_ratio; -#endif - #ifdef __hppa__ extern int pwrsw_enabled; #endif @@ -865,6 +860,17 @@ static struct ctl_table kern_table[] = { .extra1 = &zero, .extra2 = &one, }, +#ifdef CONFIG_SMP + { + .procname = "softlockup_all_cpu_backtrace", + .data = &sysctl_softlockup_all_cpu_backtrace, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &one, + }, +#endif /* CONFIG_SMP */ { .procname = "nmi_watchdog", .data = &watchdog_user_enabled, @@ -1321,7 +1327,7 @@ static struct ctl_table vm_table[] = { .maxlen = sizeof(percpu_pagelist_fraction), .mode = 0644, .proc_handler = percpu_pagelist_fraction_sysctl_handler, - .extra1 = &min_percpu_pagelist_fract, + .extra1 = &zero, }, #ifdef CONFIG_MMU { @@ -2568,11 +2574,11 @@ int proc_do_large_bitmap(struct ctl_table *table, int write, bool first = 1; size_t left = *lenp; unsigned long bitmap_len = table->maxlen; - unsigned long *bitmap = (unsigned long *) table->data; + unsigned long *bitmap = *(unsigned long **) table->data; unsigned long *tmp_bitmap = NULL; char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c; - if (!bitmap_len || !left || (*ppos && !write)) { + if (!bitmap || !bitmap_len || !left || (*ppos && !write)) { *lenp = 0; return 0; } diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 8639819f6cef..d4409356f40d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -535,6 +535,36 @@ config MMIOTRACE_TEST Say N, unless you absolutely know what you are doing. +config TRACEPOINT_BENCHMARK + bool "Add tracepoint that benchmarks tracepoints" + help + This option creates the tracepoint "benchmark:benchmark_event". + When the tracepoint is enabled, it kicks off a kernel thread that + goes into an infinite loop (calling cond_sched() to let other tasks + run), and calls the tracepoint. Each iteration will record the time + it took to write to the tracepoint and the next iteration that + data will be passed to the tracepoint itself. That is, the tracepoint + will report the time it took to do the previous tracepoint. + The string written to the tracepoint is a static string of 128 bytes + to keep the time the same. The initial string is simply a write of + "START". The second string records the cold cache time of the first + write which is not added to the rest of the calculations. + + As it is a tight loop, it benchmarks as hot cache. That's fine because + we care most about hot paths that are probably in cache already. + + An example of the output: + + START + first=3672 [COLD CACHED] + last=632 first=3672 max=632 min=632 avg=316 std=446 std^2=199712 + last=278 first=3672 max=632 min=278 avg=303 std=316 std^2=100337 + last=277 first=3672 max=632 min=277 avg=296 std=258 std^2=67064 + last=273 first=3672 max=632 min=273 avg=292 std=224 std^2=50411 + last=273 first=3672 max=632 min=273 avg=288 std=200 std^2=40389 + last=281 first=3672 max=632 min=273 avg=287 std=183 std^2=33666 + + config RING_BUFFER_BENCHMARK tristate "Ring buffer benchmark stress tester" depends on RING_BUFFER diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 1378e84fbe39..2611613f14f1 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -17,6 +17,7 @@ ifdef CONFIG_TRACING_BRANCHES KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING endif +CFLAGS_trace_benchmark.o := -I$(src) CFLAGS_trace_events_filter.o := -I$(src) obj-$(CONFIG_TRACE_CLOCK) += trace_clock.o @@ -62,4 +63,6 @@ endif obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o +obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o + libftrace-y := ftrace.o diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4a54a25afa2f..5b372e3ed675 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -62,7 +62,7 @@ #define FTRACE_HASH_DEFAULT_BITS 10 #define FTRACE_HASH_MAX_BITS 12 -#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL) +#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL) #ifdef CONFIG_DYNAMIC_FTRACE #define INIT_REGEX_LOCK(opsname) \ @@ -103,7 +103,6 @@ static int ftrace_disabled __read_mostly; static DEFINE_MUTEX(ftrace_lock); -static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; @@ -171,23 +170,6 @@ int ftrace_nr_registered_ops(void) return cnt; } -static void -ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) -{ - int bit; - - bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX); - if (bit < 0) - return; - - do_for_each_ftrace_op(op, ftrace_global_list) { - op->func(ip, parent_ip, op, regs); - } while_for_each_ftrace_op(op); - - trace_clear_recursion(bit); -} - static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *regs) { @@ -237,43 +219,6 @@ static int control_ops_alloc(struct ftrace_ops *ops) return 0; } -static void update_global_ops(void) -{ - ftrace_func_t func = ftrace_global_list_func; - void *private = NULL; - - /* The list has its own recursion protection. */ - global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; - - /* - * If there's only one function registered, then call that - * function directly. Otherwise, we need to iterate over the - * registered callers. - */ - if (ftrace_global_list == &ftrace_list_end || - ftrace_global_list->next == &ftrace_list_end) { - func = ftrace_global_list->func; - private = ftrace_global_list->private; - /* - * As we are calling the function directly. - * If it does not have recursion protection, - * the function_trace_op needs to be updated - * accordingly. - */ - if (!(ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)) - global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; - } - - /* If we filter on pids, update to use the pid function */ - if (!list_empty(&ftrace_pids)) { - set_ftrace_pid_function(func); - func = ftrace_pid_func; - } - - global_ops.func = func; - global_ops.private = private; -} - static void ftrace_sync(struct work_struct *work) { /* @@ -301,8 +246,6 @@ static void update_ftrace_function(void) { ftrace_func_t func; - update_global_ops(); - /* * If we are at the end of the list and this ops is * recursion safe and not dynamic and the arch supports passing ops, @@ -314,10 +257,7 @@ static void update_ftrace_function(void) (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && !FTRACE_FORCE_LIST_FUNC)) { /* Set the ftrace_ops that the arch callback uses */ - if (ftrace_ops_list == &global_ops) - set_function_trace_op = ftrace_global_list; - else - set_function_trace_op = ftrace_ops_list; + set_function_trace_op = ftrace_ops_list; func = ftrace_ops_list->func; } else { /* Just use the default ftrace_ops */ @@ -373,6 +313,11 @@ static void update_ftrace_function(void) ftrace_trace_function = func; } +int using_ftrace_ops_list_func(void) +{ + return ftrace_trace_function == ftrace_ops_list_func; +} + static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) { ops->next = *list; @@ -434,16 +379,9 @@ static int __register_ftrace_function(struct ftrace_ops *ops) if (ops->flags & FTRACE_OPS_FL_DELETED) return -EINVAL; - if (FTRACE_WARN_ON(ops == &global_ops)) - return -EINVAL; - if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) return -EBUSY; - /* We don't support both control and global flags set. */ - if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) - return -EINVAL; - #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS /* * If the ftrace_ops specifies SAVE_REGS, then it only can be used @@ -461,10 +399,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) if (!core_kernel_data((unsigned long)ops)) ops->flags |= FTRACE_OPS_FL_DYNAMIC; - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops); - ops->flags |= FTRACE_OPS_FL_ENABLED; - } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { + if (ops->flags & FTRACE_OPS_FL_CONTROL) { if (control_ops_alloc(ops)) return -ENOMEM; add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); @@ -484,15 +419,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) return -EBUSY; - if (FTRACE_WARN_ON(ops == &global_ops)) - return -EINVAL; - - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - ret = remove_ftrace_list_ops(&ftrace_global_list, - &global_ops, ops); - if (!ret) - ops->flags &= ~FTRACE_OPS_FL_ENABLED; - } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { + if (ops->flags & FTRACE_OPS_FL_CONTROL) { ret = remove_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); } else @@ -895,7 +822,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip, local_irq_save(flags); - stat = &__get_cpu_var(ftrace_profile_stats); + stat = this_cpu_ptr(&ftrace_profile_stats); if (!stat->hash || !ftrace_profile_enabled) goto out; @@ -926,7 +853,7 @@ static void profile_graph_return(struct ftrace_graph_ret *trace) unsigned long flags; local_irq_save(flags); - stat = &__get_cpu_var(ftrace_profile_stats); + stat = this_cpu_ptr(&ftrace_profile_stats); if (!stat->hash || !ftrace_profile_enabled) goto out; @@ -1178,7 +1105,7 @@ struct ftrace_page { static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; -static bool ftrace_hash_empty(struct ftrace_hash *hash) +static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) { return !hash || !hash->count; } @@ -1625,7 +1552,14 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); /* + * If filter_hash is set, we want to match all functions + * that are in the hash but not in the other hash. * + * If filter_hash is not set, then we are decrementing. + * That means we match anything that is in the hash + * and also in the other_hash. That is, we need to turn + * off functions in the other hash because they are disabled + * by this hash. */ if (filter_hash && in_hash && !in_other_hash) match = 1; @@ -1767,19 +1701,15 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) /* * If this record is being updated from a nop, then * return UPDATE_MAKE_CALL. - * Otherwise, if the EN flag is set, then return - * UPDATE_MODIFY_CALL_REGS to tell the caller to convert - * from the non-save regs, to a save regs function. * Otherwise, * return UPDATE_MODIFY_CALL to tell the caller to convert - * from the save regs, to a non-save regs function. + * from the save regs, to a non-save regs function or + * vice versa. */ if (flag & FTRACE_FL_ENABLED) return FTRACE_UPDATE_MAKE_CALL; - else if (rec->flags & FTRACE_FL_REGS_EN) - return FTRACE_UPDATE_MODIFY_CALL_REGS; - else - return FTRACE_UPDATE_MODIFY_CALL; + + return FTRACE_UPDATE_MODIFY_CALL; } if (update) { @@ -1821,6 +1751,42 @@ int ftrace_test_record(struct dyn_ftrace *rec, int enable) return ftrace_check_record(rec, enable, 0); } +/** + * ftrace_get_addr_new - Get the call address to set to + * @rec: The ftrace record descriptor + * + * If the record has the FTRACE_FL_REGS set, that means that it + * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS + * is not not set, then it wants to convert to the normal callback. + * + * Returns the address of the trampoline to set to + */ +unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) +{ + if (rec->flags & FTRACE_FL_REGS) + return (unsigned long)FTRACE_REGS_ADDR; + else + return (unsigned long)FTRACE_ADDR; +} + +/** + * ftrace_get_addr_curr - Get the call address that is already there + * @rec: The ftrace record descriptor + * + * The FTRACE_FL_REGS_EN is set when the record already points to + * a function that saves all the regs. Basically the '_EN' version + * represents the current state of the function. + * + * Returns the address of the trampoline that is currently being called + */ +unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) +{ + if (rec->flags & FTRACE_FL_REGS_EN) + return (unsigned long)FTRACE_REGS_ADDR; + else + return (unsigned long)FTRACE_ADDR; +} + static int __ftrace_replace_code(struct dyn_ftrace *rec, int enable) { @@ -1828,12 +1794,12 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable) unsigned long ftrace_addr; int ret; - ret = ftrace_update_record(rec, enable); + ftrace_addr = ftrace_get_addr_new(rec); - if (rec->flags & FTRACE_FL_REGS) - ftrace_addr = (unsigned long)FTRACE_REGS_ADDR; - else - ftrace_addr = (unsigned long)FTRACE_ADDR; + /* This needs to be done before we call ftrace_update_record */ + ftrace_old_addr = ftrace_get_addr_curr(rec); + + ret = ftrace_update_record(rec, enable); switch (ret) { case FTRACE_UPDATE_IGNORE: @@ -1845,13 +1811,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable) case FTRACE_UPDATE_MAKE_NOP: return ftrace_make_nop(NULL, rec, ftrace_addr); - case FTRACE_UPDATE_MODIFY_CALL_REGS: case FTRACE_UPDATE_MODIFY_CALL: - if (rec->flags & FTRACE_FL_REGS) - ftrace_old_addr = (unsigned long)FTRACE_ADDR; - else - ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR; - return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); } @@ -2115,7 +2075,6 @@ static void ftrace_startup_enable(int command) static int ftrace_startup(struct ftrace_ops *ops, int command) { - bool hash_enable = true; int ret; if (unlikely(ftrace_disabled)) @@ -2128,18 +2087,9 @@ static int ftrace_startup(struct ftrace_ops *ops, int command) ftrace_start_up++; command |= FTRACE_UPDATE_CALLS; - /* ops marked global share the filter hashes */ - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - ops = &global_ops; - /* Don't update hash if global is already set */ - if (global_start_up) - hash_enable = false; - global_start_up++; - } - ops->flags |= FTRACE_OPS_FL_ENABLED; - if (hash_enable) - ftrace_hash_rec_enable(ops, 1); + + ftrace_hash_rec_enable(ops, 1); ftrace_startup_enable(command); @@ -2148,7 +2098,6 @@ static int ftrace_startup(struct ftrace_ops *ops, int command) static int ftrace_shutdown(struct ftrace_ops *ops, int command) { - bool hash_disable = true; int ret; if (unlikely(ftrace_disabled)) @@ -2166,21 +2115,9 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command) */ WARN_ON_ONCE(ftrace_start_up < 0); - if (ops->flags & FTRACE_OPS_FL_GLOBAL) { - ops = &global_ops; - global_start_up--; - WARN_ON_ONCE(global_start_up < 0); - /* Don't update hash if global still has users */ - if (global_start_up) { - WARN_ON_ONCE(!ftrace_start_up); - hash_disable = false; - } - } - - if (hash_disable) - ftrace_hash_rec_disable(ops, 1); + ftrace_hash_rec_disable(ops, 1); - if (ops != &global_ops || !global_start_up) + if (!global_start_up) ops->flags &= ~FTRACE_OPS_FL_ENABLED; command |= FTRACE_UPDATE_CALLS; @@ -3524,10 +3461,6 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, struct ftrace_hash *hash; int ret; - /* All global ops uses the global ops filters */ - if (ops->flags & FTRACE_OPS_FL_GLOBAL) - ops = &global_ops; - if (unlikely(ftrace_disabled)) return -ENODEV; @@ -3639,8 +3572,7 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, } EXPORT_SYMBOL_GPL(ftrace_set_notrace); /** - * ftrace_set_filter - set a function to filter on in ftrace - * @ops - the ops to set the filter with + * ftrace_set_global_filter - set a function to filter on with global tracers * @buf - the string that holds the function filter text. * @len - the length of the string. * @reset - non zero to reset all filters before applying this filter. @@ -3655,8 +3587,7 @@ void ftrace_set_global_filter(unsigned char *buf, int len, int reset) EXPORT_SYMBOL_GPL(ftrace_set_global_filter); /** - * ftrace_set_notrace - set a function to not trace in ftrace - * @ops - the ops to set the notrace filter with + * ftrace_set_global_notrace - set a function to not trace with global tracers * @buf - the string that holds the function notrace text. * @len - the length of the string. * @reset - non zero to reset all filters before applying this filter. @@ -4443,6 +4374,34 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) #endif /* CONFIG_DYNAMIC_FTRACE */ +__init void ftrace_init_global_array_ops(struct trace_array *tr) +{ + tr->ops = &global_ops; + tr->ops->private = tr; +} + +void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) +{ + /* If we filter on pids, update to use the pid function */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { + if (WARN_ON(tr->ops->func != ftrace_stub)) + printk("ftrace ops had %pS for function\n", + tr->ops->func); + /* Only the top level instance does pid tracing */ + if (!list_empty(&ftrace_pids)) { + set_ftrace_pid_function(func); + func = ftrace_pid_func; + } + } + tr->ops->func = func; + tr->ops->private = tr; +} + +void ftrace_reset_array_ops(struct trace_array *tr) +{ + tr->ops->func = ftrace_stub; +} + static void ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *regs) @@ -4501,9 +4460,16 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, */ preempt_disable_notrace(); do_for_each_ftrace_op(op, ftrace_ops_list) { - if (ftrace_ops_test(op, ip, regs)) + if (ftrace_ops_test(op, ip, regs)) { + if (WARN_ON(!op->func)) { + function_trace_stop = 1; + printk("op=%p %pS\n", op, op); + goto out; + } op->func(ip, parent_ip, op, regs); + } } while_for_each_ftrace_op(op); +out: preempt_enable_notrace(); trace_clear_recursion(bit); } @@ -4908,7 +4874,6 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, #ifdef CONFIG_FUNCTION_GRAPH_TRACER static int ftrace_graph_active; -static struct notifier_block ftrace_suspend_notifier; int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) { @@ -5054,13 +5019,6 @@ ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, return NOTIFY_DONE; } -/* Just a place holder for function graph */ -static struct ftrace_ops fgraph_ops __read_mostly = { - .func = ftrace_stub, - .flags = FTRACE_OPS_FL_STUB | FTRACE_OPS_FL_GLOBAL | - FTRACE_OPS_FL_RECURSION_SAFE, -}; - static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) { if (!ftrace_ops_test(&global_ops, trace->func, NULL)) @@ -5085,6 +5043,10 @@ static void update_function_graph_func(void) ftrace_graph_entry = ftrace_graph_entry_test; } +static struct notifier_block ftrace_suspend_notifier = { + .notifier_call = ftrace_suspend_notifier_call, +}; + int register_ftrace_graph(trace_func_graph_ret_t retfunc, trace_func_graph_ent_t entryfunc) { @@ -5098,7 +5060,6 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, goto out; } - ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; register_pm_notifier(&ftrace_suspend_notifier); ftrace_graph_active++; @@ -5120,7 +5081,10 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, ftrace_graph_entry = ftrace_graph_entry_test; update_function_graph_func(); - ret = ftrace_startup(&fgraph_ops, FTRACE_START_FUNC_RET); + /* Function graph doesn't use the .func field of global_ops */ + global_ops.flags |= FTRACE_OPS_FL_STUB; + + ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); out: mutex_unlock(&ftrace_lock); @@ -5138,7 +5102,8 @@ void unregister_ftrace_graph(void) ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; ftrace_graph_entry = ftrace_graph_entry_stub; __ftrace_graph_entry = ftrace_graph_entry_stub; - ftrace_shutdown(&fgraph_ops, FTRACE_STOP_FUNC_RET); + ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); + global_ops.flags &= ~FTRACE_OPS_FL_STUB; unregister_pm_notifier(&ftrace_suspend_notifier); unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index c634868c2921..7c56c3d06943 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -543,7 +543,7 @@ static void rb_wake_up_waiters(struct irq_work *work) * as data is added to any of the @buffer's cpu buffers. Otherwise * it will wait for data to be added to a specific cpu buffer. */ -void ring_buffer_wait(struct ring_buffer *buffer, int cpu) +int ring_buffer_wait(struct ring_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; DEFINE_WAIT(wait); @@ -557,6 +557,8 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu) if (cpu == RING_BUFFER_ALL_CPUS) work = &buffer->irq_work; else { + if (!cpumask_test_cpu(cpu, buffer->cpumask)) + return -ENODEV; cpu_buffer = buffer->buffers[cpu]; work = &cpu_buffer->irq_work; } @@ -591,6 +593,7 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu) schedule(); finish_wait(&work->waiters, &wait); + return 0; } /** diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 737b0efa1a62..f243444a3772 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -275,7 +275,7 @@ int call_filter_check_discard(struct ftrace_event_call *call, void *rec, } EXPORT_SYMBOL_GPL(call_filter_check_discard); -cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) +static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) { u64 ts; @@ -599,7 +599,7 @@ static int alloc_snapshot(struct trace_array *tr) return 0; } -void free_snapshot(struct trace_array *tr) +static void free_snapshot(struct trace_array *tr) { /* * We don't free the ring buffer. instead, resize it because @@ -963,27 +963,9 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) return cnt; } -/* - * ftrace_max_lock is used to protect the swapping of buffers - * when taking a max snapshot. The buffers themselves are - * protected by per_cpu spinlocks. But the action of the swap - * needs its own lock. - * - * This is defined as a arch_spinlock_t in order to help - * with performance when lockdep debugging is enabled. - * - * It is also used in other places outside the update_max_tr - * so it needs to be defined outside of the - * CONFIG_TRACER_MAX_TRACE. - */ -static arch_spinlock_t ftrace_max_lock = - (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; - unsigned long __read_mostly tracing_thresh; #ifdef CONFIG_TRACER_MAX_TRACE -unsigned long __read_mostly tracing_max_latency; - /* * Copy the new maximum trace into the separate maximum-trace * structure. (this way the maximum trace is permanently saved, @@ -1000,7 +982,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) max_buf->cpu = cpu; max_buf->time_start = data->preempt_timestamp; - max_data->saved_latency = tracing_max_latency; + max_data->saved_latency = tr->max_latency; max_data->critical_start = data->critical_start; max_data->critical_end = data->critical_end; @@ -1048,14 +1030,14 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) return; } - arch_spin_lock(&ftrace_max_lock); + arch_spin_lock(&tr->max_lock); buf = tr->trace_buffer.buffer; tr->trace_buffer.buffer = tr->max_buffer.buffer; tr->max_buffer.buffer = buf; __update_max_tr(tr, tsk, cpu); - arch_spin_unlock(&ftrace_max_lock); + arch_spin_unlock(&tr->max_lock); } /** @@ -1081,7 +1063,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) return; } - arch_spin_lock(&ftrace_max_lock); + arch_spin_lock(&tr->max_lock); ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu); @@ -1099,17 +1081,17 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); __update_max_tr(tr, tsk, cpu); - arch_spin_unlock(&ftrace_max_lock); + arch_spin_unlock(&tr->max_lock); } #endif /* CONFIG_TRACER_MAX_TRACE */ -static void default_wait_pipe(struct trace_iterator *iter) +static int wait_on_pipe(struct trace_iterator *iter) { /* Iterators are static, they should be filled or empty */ if (trace_buffer_iter(iter, iter->cpu_file)) - return; + return 0; - ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file); + return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file); } #ifdef CONFIG_FTRACE_STARTUP_TEST @@ -1220,8 +1202,6 @@ int register_tracer(struct tracer *type) else if (!type->flags->opts) type->flags->opts = dummy_tracer_opt; - if (!type->wait_pipe) - type->wait_pipe = default_wait_pipe; ret = run_tracer_selftest(type); if (ret < 0) @@ -1305,22 +1285,71 @@ void tracing_reset_all_online_cpus(void) } } -#define SAVED_CMDLINES 128 +#define SAVED_CMDLINES_DEFAULT 128 #define NO_CMDLINE_MAP UINT_MAX -static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; -static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; -static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; -static int cmdline_idx; static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; +struct saved_cmdlines_buffer { + unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; + unsigned *map_cmdline_to_pid; + unsigned cmdline_num; + int cmdline_idx; + char *saved_cmdlines; +}; +static struct saved_cmdlines_buffer *savedcmd; /* temporary disable recording */ static atomic_t trace_record_cmdline_disabled __read_mostly; -static void trace_init_cmdlines(void) +static inline char *get_saved_cmdlines(int idx) +{ + return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN]; +} + +static inline void set_cmdline(int idx, const char *cmdline) +{ + memcpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN); +} + +static int allocate_cmdlines_buffer(unsigned int val, + struct saved_cmdlines_buffer *s) { - memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); - memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); - cmdline_idx = 0; + s->map_cmdline_to_pid = kmalloc(val * sizeof(*s->map_cmdline_to_pid), + GFP_KERNEL); + if (!s->map_cmdline_to_pid) + return -ENOMEM; + + s->saved_cmdlines = kmalloc(val * TASK_COMM_LEN, GFP_KERNEL); + if (!s->saved_cmdlines) { + kfree(s->map_cmdline_to_pid); + return -ENOMEM; + } + + s->cmdline_idx = 0; + s->cmdline_num = val; + memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP, + sizeof(s->map_pid_to_cmdline)); + memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP, + val * sizeof(*s->map_cmdline_to_pid)); + + return 0; +} + +static int trace_create_savedcmd(void) +{ + int ret; + + savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL); + if (!savedcmd) + return -ENOMEM; + + ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd); + if (ret < 0) { + kfree(savedcmd); + savedcmd = NULL; + return -ENOMEM; + } + + return 0; } int is_tracing_stopped(void) @@ -1353,7 +1382,7 @@ void tracing_start(void) } /* Prevent the buffers from switching */ - arch_spin_lock(&ftrace_max_lock); + arch_spin_lock(&global_trace.max_lock); buffer = global_trace.trace_buffer.buffer; if (buffer) @@ -1365,9 +1394,8 @@ void tracing_start(void) ring_buffer_record_enable(buffer); #endif - arch_spin_unlock(&ftrace_max_lock); + arch_spin_unlock(&global_trace.max_lock); - ftrace_start(); out: raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); } @@ -1414,13 +1442,12 @@ void tracing_stop(void) struct ring_buffer *buffer; unsigned long flags; - ftrace_stop(); raw_spin_lock_irqsave(&global_trace.start_lock, flags); if (global_trace.stop_count++) goto out; /* Prevent the buffers from switching */ - arch_spin_lock(&ftrace_max_lock); + arch_spin_lock(&global_trace.max_lock); buffer = global_trace.trace_buffer.buffer; if (buffer) @@ -1432,7 +1459,7 @@ void tracing_stop(void) ring_buffer_record_disable(buffer); #endif - arch_spin_unlock(&ftrace_max_lock); + arch_spin_unlock(&global_trace.max_lock); out: raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); @@ -1461,12 +1488,12 @@ static void tracing_stop_tr(struct trace_array *tr) void trace_stop_cmdline_recording(void); -static void trace_save_cmdline(struct task_struct *tsk) +static int trace_save_cmdline(struct task_struct *tsk) { unsigned pid, idx; if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) - return; + return 0; /* * It's not the end of the world if we don't get @@ -1475,11 +1502,11 @@ static void trace_save_cmdline(struct task_struct *tsk) * so if we miss here, then better luck next time. */ if (!arch_spin_trylock(&trace_cmdline_lock)) - return; + return 0; - idx = map_pid_to_cmdline[tsk->pid]; + idx = savedcmd->map_pid_to_cmdline[tsk->pid]; if (idx == NO_CMDLINE_MAP) { - idx = (cmdline_idx + 1) % SAVED_CMDLINES; + idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num; /* * Check whether the cmdline buffer at idx has a pid @@ -1487,22 +1514,24 @@ static void trace_save_cmdline(struct task_struct *tsk) * need to clear the map_pid_to_cmdline. Otherwise we * would read the new comm for the old pid. */ - pid = map_cmdline_to_pid[idx]; + pid = savedcmd->map_cmdline_to_pid[idx]; if (pid != NO_CMDLINE_MAP) - map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; + savedcmd->map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; - map_cmdline_to_pid[idx] = tsk->pid; - map_pid_to_cmdline[tsk->pid] = idx; + savedcmd->map_cmdline_to_pid[idx] = tsk->pid; + savedcmd->map_pid_to_cmdline[tsk->pid] = idx; - cmdline_idx = idx; + savedcmd->cmdline_idx = idx; } - memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); + set_cmdline(idx, tsk->comm); arch_spin_unlock(&trace_cmdline_lock); + + return 1; } -void trace_find_cmdline(int pid, char comm[]) +static void __trace_find_cmdline(int pid, char comm[]) { unsigned map; @@ -1521,13 +1550,19 @@ void trace_find_cmdline(int pid, char comm[]) return; } - preempt_disable(); - arch_spin_lock(&trace_cmdline_lock); - map = map_pid_to_cmdline[pid]; + map = savedcmd->map_pid_to_cmdline[pid]; if (map != NO_CMDLINE_MAP) - strcpy(comm, saved_cmdlines[map]); + strcpy(comm, get_saved_cmdlines(map)); else strcpy(comm, "<...>"); +} + +void trace_find_cmdline(int pid, char comm[]) +{ + preempt_disable(); + arch_spin_lock(&trace_cmdline_lock); + + __trace_find_cmdline(pid, comm); arch_spin_unlock(&trace_cmdline_lock); preempt_enable(); @@ -1541,9 +1576,8 @@ void tracing_record_cmdline(struct task_struct *tsk) if (!__this_cpu_read(trace_cmdline_save)) return; - __this_cpu_write(trace_cmdline_save, false); - - trace_save_cmdline(tsk); + if (trace_save_cmdline(tsk)) + __this_cpu_write(trace_cmdline_save, false); } void @@ -1746,7 +1780,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, */ barrier(); if (use_stack == 1) { - trace.entries = &__get_cpu_var(ftrace_stack).calls[0]; + trace.entries = this_cpu_ptr(ftrace_stack.calls); trace.max_entries = FTRACE_STACK_MAX_ENTRIES; if (regs) @@ -1995,7 +2029,21 @@ void trace_printk_init_buffers(void) if (alloc_percpu_trace_buffer()) return; - pr_info("ftrace: Allocated trace_printk buffers\n"); + /* trace_printk() is for debug use only. Don't use it in production. */ + + pr_warning("\n**********************************************************\n"); + pr_warning("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warning("** **\n"); + pr_warning("** trace_printk() being used. Allocating extra memory. **\n"); + pr_warning("** **\n"); + pr_warning("** This means that this is a DEBUG kernel and it is **\n"); + pr_warning("** unsafe for produciton use. **\n"); + pr_warning("** **\n"); + pr_warning("** If you see this message and you are not debugging **\n"); + pr_warning("** the kernel, report this immediately to your vendor! **\n"); + pr_warning("** **\n"); + pr_warning("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warning("**********************************************************\n"); /* Expand the buffers to set size */ tracing_update_buffers(); @@ -3333,7 +3381,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, mutex_lock(&tracing_cpumask_update_lock); local_irq_disable(); - arch_spin_lock(&ftrace_max_lock); + arch_spin_lock(&tr->max_lock); for_each_tracing_cpu(cpu) { /* * Increase/decrease the disabled counter if we are @@ -3350,7 +3398,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu); } } - arch_spin_unlock(&ftrace_max_lock); + arch_spin_unlock(&tr->max_lock); local_irq_enable(); cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); @@ -3592,6 +3640,7 @@ static const char readme_msg[] = " trace_options\t\t- Set format or modify how tracing happens\n" "\t\t\t Disable an option by adding a suffix 'no' to the\n" "\t\t\t option name\n" + " saved_cmdlines_size\t- echo command number in here to store comm-pid list\n" #ifdef CONFIG_DYNAMIC_FTRACE "\n available_filter_functions - list of functions that can be filtered on\n" " set_ftrace_filter\t- echo function name in here to only trace these\n" @@ -3705,55 +3754,153 @@ static const struct file_operations tracing_readme_fops = { .llseek = generic_file_llseek, }; +static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos) +{ + unsigned int *ptr = v; + + if (*pos || m->count) + ptr++; + + (*pos)++; + + for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num]; + ptr++) { + if (*ptr == -1 || *ptr == NO_CMDLINE_MAP) + continue; + + return ptr; + } + + return NULL; +} + +static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos) +{ + void *v; + loff_t l = 0; + + preempt_disable(); + arch_spin_lock(&trace_cmdline_lock); + + v = &savedcmd->map_cmdline_to_pid[0]; + while (l <= *pos) { + v = saved_cmdlines_next(m, v, &l); + if (!v) + return NULL; + } + + return v; +} + +static void saved_cmdlines_stop(struct seq_file *m, void *v) +{ + arch_spin_unlock(&trace_cmdline_lock); + preempt_enable(); +} + +static int saved_cmdlines_show(struct seq_file *m, void *v) +{ + char buf[TASK_COMM_LEN]; + unsigned int *pid = v; + + __trace_find_cmdline(*pid, buf); + seq_printf(m, "%d %s\n", *pid, buf); + return 0; +} + +static const struct seq_operations tracing_saved_cmdlines_seq_ops = { + .start = saved_cmdlines_start, + .next = saved_cmdlines_next, + .stop = saved_cmdlines_stop, + .show = saved_cmdlines_show, +}; + +static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp) +{ + if (tracing_disabled) + return -ENODEV; + + return seq_open(filp, &tracing_saved_cmdlines_seq_ops); +} + +static const struct file_operations tracing_saved_cmdlines_fops = { + .open = tracing_saved_cmdlines_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + static ssize_t -tracing_saved_cmdlines_read(struct file *file, char __user *ubuf, - size_t cnt, loff_t *ppos) +tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) { - char *buf_comm; - char *file_buf; - char *buf; - int len = 0; - int pid; - int i; + char buf[64]; + int r; - file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL); - if (!file_buf) + arch_spin_lock(&trace_cmdline_lock); + r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num); + arch_spin_unlock(&trace_cmdline_lock); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s) +{ + kfree(s->saved_cmdlines); + kfree(s->map_cmdline_to_pid); + kfree(s); +} + +static int tracing_resize_saved_cmdlines(unsigned int val) +{ + struct saved_cmdlines_buffer *s, *savedcmd_temp; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) return -ENOMEM; - buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL); - if (!buf_comm) { - kfree(file_buf); + if (allocate_cmdlines_buffer(val, s) < 0) { + kfree(s); return -ENOMEM; } - buf = file_buf; + arch_spin_lock(&trace_cmdline_lock); + savedcmd_temp = savedcmd; + savedcmd = s; + arch_spin_unlock(&trace_cmdline_lock); + free_saved_cmdlines_buffer(savedcmd_temp); - for (i = 0; i < SAVED_CMDLINES; i++) { - int r; + return 0; +} - pid = map_cmdline_to_pid[i]; - if (pid == -1 || pid == NO_CMDLINE_MAP) - continue; +static ssize_t +tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + unsigned long val; + int ret; - trace_find_cmdline(pid, buf_comm); - r = sprintf(buf, "%d %s\n", pid, buf_comm); - buf += r; - len += r; - } + ret = kstrtoul_from_user(ubuf, cnt, 10, &val); + if (ret) + return ret; - len = simple_read_from_buffer(ubuf, cnt, ppos, - file_buf, len); + /* must have at least 1 entry or less than PID_MAX_DEFAULT */ + if (!val || val > PID_MAX_DEFAULT) + return -EINVAL; - kfree(file_buf); - kfree(buf_comm); + ret = tracing_resize_saved_cmdlines((unsigned int)val); + if (ret < 0) + return ret; - return len; + *ppos += cnt; + + return cnt; } -static const struct file_operations tracing_saved_cmdlines_fops = { - .open = tracing_open_generic, - .read = tracing_saved_cmdlines_read, - .llseek = generic_file_llseek, +static const struct file_operations tracing_saved_cmdlines_size_fops = { + .open = tracing_open_generic, + .read = tracing_saved_cmdlines_size_read, + .write = tracing_saved_cmdlines_size_write, }; static ssize_t @@ -4225,29 +4372,11 @@ tracing_poll_pipe(struct file *filp, poll_table *poll_table) return trace_poll(iter, filp, poll_table); } -/* - * This is a make-shift waitqueue. - * A tracer might use this callback on some rare cases: - * - * 1) the current tracer might hold the runqueue lock when it wakes up - * a reader, hence a deadlock (sched, function, and function graph tracers) - * 2) the function tracers, trace all functions, we don't want - * the overhead of calling wake_up and friends - * (and tracing them too) - * - * Anyway, this is really very primitive wakeup. - */ -void poll_wait_pipe(struct trace_iterator *iter) -{ - set_current_state(TASK_INTERRUPTIBLE); - /* sleep for 100 msecs, and try again. */ - schedule_timeout(HZ / 10); -} - /* Must be called with trace_types_lock mutex held. */ static int tracing_wait_pipe(struct file *filp) { struct trace_iterator *iter = filp->private_data; + int ret; while (trace_empty(iter)) { @@ -4255,15 +4384,6 @@ static int tracing_wait_pipe(struct file *filp) return -EAGAIN; } - mutex_unlock(&iter->mutex); - - iter->trace->wait_pipe(iter); - - mutex_lock(&iter->mutex); - - if (signal_pending(current)) - return -EINTR; - /* * We block until we read something and tracing is disabled. * We still block if tracing is disabled, but we have never @@ -4275,6 +4395,18 @@ static int tracing_wait_pipe(struct file *filp) */ if (!tracing_is_on() && iter->pos) break; + + mutex_unlock(&iter->mutex); + + ret = wait_on_pipe(iter); + + mutex_lock(&iter->mutex); + + if (ret) + return ret; + + if (signal_pending(current)) + return -EINTR; } return 1; @@ -5197,8 +5329,12 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, goto out_unlock; } mutex_unlock(&trace_types_lock); - iter->trace->wait_pipe(iter); + ret = wait_on_pipe(iter); mutex_lock(&trace_types_lock); + if (ret) { + size = ret; + goto out_unlock; + } if (signal_pending(current)) { size = -EINTR; goto out_unlock; @@ -5408,8 +5544,10 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, goto out; } mutex_unlock(&trace_types_lock); - iter->trace->wait_pipe(iter); + ret = wait_on_pipe(iter); mutex_lock(&trace_types_lock); + if (ret) + goto out; if (signal_pending(current)) { ret = -EINTR; goto out; @@ -6102,6 +6240,28 @@ static int allocate_trace_buffers(struct trace_array *tr, int size) return 0; } +static void free_trace_buffer(struct trace_buffer *buf) +{ + if (buf->buffer) { + ring_buffer_free(buf->buffer); + buf->buffer = NULL; + free_percpu(buf->data); + buf->data = NULL; + } +} + +static void free_trace_buffers(struct trace_array *tr) +{ + if (!tr) + return; + + free_trace_buffer(&tr->trace_buffer); + +#ifdef CONFIG_TRACER_MAX_TRACE + free_trace_buffer(&tr->max_buffer); +#endif +} + static int new_instance_create(const char *name) { struct trace_array *tr; @@ -6131,6 +6291,8 @@ static int new_instance_create(const char *name) raw_spin_lock_init(&tr->start_lock); + tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; + tr->current_trace = &nop_trace; INIT_LIST_HEAD(&tr->systems); @@ -6158,8 +6320,7 @@ static int new_instance_create(const char *name) return 0; out_free_tr: - if (tr->trace_buffer.buffer) - ring_buffer_free(tr->trace_buffer.buffer); + free_trace_buffers(tr); free_cpumask_var(tr->tracing_cpumask); kfree(tr->name); kfree(tr); @@ -6199,8 +6360,7 @@ static int instance_delete(const char *name) event_trace_del_tracer(tr); ftrace_destroy_function_files(tr); debugfs_remove_recursive(tr->dir); - free_percpu(tr->trace_buffer.data); - ring_buffer_free(tr->trace_buffer.buffer); + free_trace_buffers(tr); kfree(tr->name); kfree(tr); @@ -6328,6 +6488,11 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("tracing_on", 0644, d_tracer, tr, &rb_simple_fops); +#ifdef CONFIG_TRACER_MAX_TRACE + trace_create_file("tracing_max_latency", 0644, d_tracer, + &tr->max_latency, &tracing_max_lat_fops); +#endif + if (ftrace_create_function_files(tr, d_tracer)) WARN(1, "Could not allocate function filter files"); @@ -6353,11 +6518,6 @@ static __init int tracer_init_debugfs(void) init_tracer_debugfs(&global_trace, d_tracer); -#ifdef CONFIG_TRACER_MAX_TRACE - trace_create_file("tracing_max_latency", 0644, d_tracer, - &tracing_max_latency, &tracing_max_lat_fops); -#endif - trace_create_file("tracing_thresh", 0644, d_tracer, &tracing_thresh, &tracing_max_lat_fops); @@ -6367,6 +6527,9 @@ static __init int tracer_init_debugfs(void) trace_create_file("saved_cmdlines", 0444, d_tracer, NULL, &tracing_saved_cmdlines_fops); + trace_create_file("saved_cmdlines_size", 0644, d_tracer, + NULL, &tracing_saved_cmdlines_size_fops); + #ifdef CONFIG_DYNAMIC_FTRACE trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, &ftrace_update_tot_cnt, &tracing_dyn_info_fops); @@ -6603,18 +6766,19 @@ __init static int tracer_alloc_buffers(void) if (!temp_buffer) goto out_free_cpumask; + if (trace_create_savedcmd() < 0) + goto out_free_temp_buffer; + /* TODO: make the number of buffers hot pluggable with CPUS */ if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); WARN_ON(1); - goto out_free_temp_buffer; + goto out_free_savedcmd; } if (global_trace.buffer_disabled) tracing_off(); - trace_init_cmdlines(); - if (trace_boot_clock) { ret = tracing_set_clock(&global_trace, trace_boot_clock); if (ret < 0) @@ -6629,6 +6793,10 @@ __init static int tracer_alloc_buffers(void) */ global_trace.current_trace = &nop_trace; + global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; + + ftrace_init_global_array_ops(&global_trace); + register_tracer(&nop_trace); /* All seems OK, enable tracing */ @@ -6656,13 +6824,11 @@ __init static int tracer_alloc_buffers(void) return 0; +out_free_savedcmd: + free_saved_cmdlines_buffer(savedcmd); out_free_temp_buffer: ring_buffer_free(temp_buffer); out_free_cpumask: - free_percpu(global_trace.trace_buffer.data); -#ifdef CONFIG_TRACER_MAX_TRACE - free_percpu(global_trace.max_buffer.data); -#endif free_cpumask_var(global_trace.tracing_cpumask); out_free_buffer_mask: free_cpumask_var(tracing_buffer_mask); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2e29d7ba5a52..9258f5a815db 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -190,7 +190,22 @@ struct trace_array { */ struct trace_buffer max_buffer; bool allocated_snapshot; + unsigned long max_latency; #endif + /* + * max_lock is used to protect the swapping of buffers + * when taking a max snapshot. The buffers themselves are + * protected by per_cpu spinlocks. But the action of the swap + * needs its own lock. + * + * This is defined as a arch_spinlock_t in order to help + * with performance when lockdep debugging is enabled. + * + * It is also used in other places outside the update_max_tr + * so it needs to be defined outside of the + * CONFIG_TRACER_MAX_TRACE. + */ + arch_spinlock_t max_lock; int buffer_disabled; #ifdef CONFIG_FTRACE_SYSCALLS int sys_refcount_enter; @@ -237,6 +252,9 @@ static inline struct trace_array *top_trace_array(void) { struct trace_array *tr; + if (list_empty(&ftrace_trace_arrays)) + return NULL; + tr = list_entry(ftrace_trace_arrays.prev, typeof(*tr), list); WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); @@ -323,7 +341,6 @@ struct tracer_flags { * @stop: called when tracing is paused (echo 0 > tracing_enabled) * @open: called when the trace file is opened * @pipe_open: called when the trace_pipe file is opened - * @wait_pipe: override how the user waits for traces on trace_pipe * @close: called when the trace file is released * @pipe_close: called when the trace_pipe file is released * @read: override the default read callback on trace_pipe @@ -342,7 +359,6 @@ struct tracer { void (*stop)(struct trace_array *tr); void (*open)(struct trace_iterator *iter); void (*pipe_open)(struct trace_iterator *iter); - void (*wait_pipe)(struct trace_iterator *iter); void (*close)(struct trace_iterator *iter); void (*pipe_close)(struct trace_iterator *iter); ssize_t (*read)(struct trace_iterator *iter, @@ -416,13 +432,7 @@ enum { TRACE_FTRACE_IRQ_BIT, TRACE_FTRACE_SIRQ_BIT, - /* GLOBAL_BITs must be greater than FTRACE_BITs */ - TRACE_GLOBAL_BIT, - TRACE_GLOBAL_NMI_BIT, - TRACE_GLOBAL_IRQ_BIT, - TRACE_GLOBAL_SIRQ_BIT, - - /* INTERNAL_BITs must be greater than GLOBAL_BITs */ + /* INTERNAL_BITs must be greater than FTRACE_BITs */ TRACE_INTERNAL_BIT, TRACE_INTERNAL_NMI_BIT, TRACE_INTERNAL_IRQ_BIT, @@ -449,9 +459,6 @@ enum { #define TRACE_FTRACE_START TRACE_FTRACE_BIT #define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1) -#define TRACE_GLOBAL_START TRACE_GLOBAL_BIT -#define TRACE_GLOBAL_MAX ((1 << (TRACE_GLOBAL_START + TRACE_CONTEXT_BITS)) - 1) - #define TRACE_LIST_START TRACE_INTERNAL_BIT #define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1) @@ -560,8 +567,6 @@ void trace_init_global_iter(struct trace_iterator *iter); void tracing_iter_reset(struct trace_iterator *iter, int cpu); -void poll_wait_pipe(struct trace_iterator *iter); - void tracing_sched_switch_trace(struct trace_array *tr, struct task_struct *prev, struct task_struct *next, @@ -608,8 +613,6 @@ extern unsigned long nsecs_to_usecs(unsigned long nsecs); extern unsigned long tracing_thresh; #ifdef CONFIG_TRACER_MAX_TRACE -extern unsigned long tracing_max_latency; - void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu); void update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu); @@ -724,6 +727,8 @@ extern unsigned long trace_flags; #define TRACE_GRAPH_PRINT_PROC 0x8 #define TRACE_GRAPH_PRINT_DURATION 0x10 #define TRACE_GRAPH_PRINT_ABS_TIME 0x20 +#define TRACE_GRAPH_PRINT_IRQS 0x40 +#define TRACE_GRAPH_PRINT_TAIL 0x80 #define TRACE_GRAPH_PRINT_FILL_SHIFT 28 #define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT) @@ -823,6 +828,10 @@ extern int ftrace_is_dead(void); int ftrace_create_function_files(struct trace_array *tr, struct dentry *parent); void ftrace_destroy_function_files(struct trace_array *tr); +void ftrace_init_global_array_ops(struct trace_array *tr); +void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func); +void ftrace_reset_array_ops(struct trace_array *tr); +int using_ftrace_ops_list_func(void); #else static inline int ftrace_trace_task(struct task_struct *task) { @@ -836,6 +845,11 @@ ftrace_create_function_files(struct trace_array *tr, return 0; } static inline void ftrace_destroy_function_files(struct trace_array *tr) { } +static inline __init void +ftrace_init_global_array_ops(struct trace_array *tr) { } +static inline void ftrace_reset_array_ops(struct trace_array *tr) { } +/* ftace_func_t type is not defined, use macro instead of static inline */ +#define ftrace_init_array_ops(tr, func) do { } while (0) #endif /* CONFIG_FUNCTION_TRACER */ #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c new file mode 100644 index 000000000000..40a14cbcf8e0 --- /dev/null +++ b/kernel/trace/trace_benchmark.c @@ -0,0 +1,198 @@ +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/kthread.h> +#include <linux/trace_clock.h> + +#define CREATE_TRACE_POINTS +#include "trace_benchmark.h" + +static struct task_struct *bm_event_thread; + +static char bm_str[BENCHMARK_EVENT_STRLEN] = "START"; + +static u64 bm_total; +static u64 bm_totalsq; +static u64 bm_last; +static u64 bm_max; +static u64 bm_min; +static u64 bm_first; +static u64 bm_cnt; +static u64 bm_stddev; +static unsigned int bm_avg; +static unsigned int bm_std; + +/* + * This gets called in a loop recording the time it took to write + * the tracepoint. What it writes is the time statistics of the last + * tracepoint write. As there is nothing to write the first time + * it simply writes "START". As the first write is cold cache and + * the rest is hot, we save off that time in bm_first and it is + * reported as "first", which is shown in the second write to the + * tracepoint. The "first" field is writen within the statics from + * then on but never changes. + */ +static void trace_do_benchmark(void) +{ + u64 start; + u64 stop; + u64 delta; + u64 stddev; + u64 seed; + u64 last_seed; + unsigned int avg; + unsigned int std = 0; + + /* Only run if the tracepoint is actually active */ + if (!trace_benchmark_event_enabled()) + return; + + local_irq_disable(); + start = trace_clock_local(); + trace_benchmark_event(bm_str); + stop = trace_clock_local(); + local_irq_enable(); + + bm_cnt++; + + delta = stop - start; + + /* + * The first read is cold cached, keep it separate from the + * other calculations. + */ + if (bm_cnt == 1) { + bm_first = delta; + scnprintf(bm_str, BENCHMARK_EVENT_STRLEN, + "first=%llu [COLD CACHED]", bm_first); + return; + } + + bm_last = delta; + + if (delta > bm_max) + bm_max = delta; + if (!bm_min || delta < bm_min) + bm_min = delta; + + /* + * When bm_cnt is greater than UINT_MAX, it breaks the statistics + * accounting. Freeze the statistics when that happens. + * We should have enough data for the avg and stddev anyway. + */ + if (bm_cnt > UINT_MAX) { + scnprintf(bm_str, BENCHMARK_EVENT_STRLEN, + "last=%llu first=%llu max=%llu min=%llu ** avg=%u std=%d std^2=%lld", + bm_last, bm_first, bm_max, bm_min, bm_avg, bm_std, bm_stddev); + return; + } + + bm_total += delta; + bm_totalsq += delta * delta; + + + if (bm_cnt > 1) { + /* + * Apply Welford's method to calculate standard deviation: + * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) + */ + stddev = (u64)bm_cnt * bm_totalsq - bm_total * bm_total; + do_div(stddev, (u32)bm_cnt); + do_div(stddev, (u32)bm_cnt - 1); + } else + stddev = 0; + + delta = bm_total; + do_div(delta, bm_cnt); + avg = delta; + + if (stddev > 0) { + int i = 0; + /* + * stddev is the square of standard deviation but + * we want the actualy number. Use the average + * as our seed to find the std. + * + * The next try is: + * x = (x + N/x) / 2 + * + * Where N is the squared number to find the square + * root of. + */ + seed = avg; + do { + last_seed = seed; + seed = stddev; + if (!last_seed) + break; + do_div(seed, last_seed); + seed += last_seed; + do_div(seed, 2); + } while (i++ < 10 && last_seed != seed); + + std = seed; + } + + scnprintf(bm_str, BENCHMARK_EVENT_STRLEN, + "last=%llu first=%llu max=%llu min=%llu avg=%u std=%d std^2=%lld", + bm_last, bm_first, bm_max, bm_min, avg, std, stddev); + + bm_std = std; + bm_avg = avg; + bm_stddev = stddev; +} + +static int benchmark_event_kthread(void *arg) +{ + /* sleep a bit to make sure the tracepoint gets activated */ + msleep(100); + + while (!kthread_should_stop()) { + + trace_do_benchmark(); + + /* + * We don't go to sleep, but let others + * run as well. + */ + cond_resched(); + } + + return 0; +} + +/* + * When the benchmark tracepoint is enabled, it calls this + * function and the thread that calls the tracepoint is created. + */ +void trace_benchmark_reg(void) +{ + bm_event_thread = kthread_run(benchmark_event_kthread, + NULL, "event_benchmark"); + WARN_ON(!bm_event_thread); +} + +/* + * When the benchmark tracepoint is disabled, it calls this + * function and the thread that calls the tracepoint is deleted + * and all the numbers are reset. + */ +void trace_benchmark_unreg(void) +{ + if (!bm_event_thread) + return; + + kthread_stop(bm_event_thread); + + strcpy(bm_str, "START"); + bm_total = 0; + bm_totalsq = 0; + bm_last = 0; + bm_max = 0; + bm_min = 0; + bm_cnt = 0; + /* These don't need to be reset but reset them anyway */ + bm_first = 0; + bm_std = 0; + bm_avg = 0; + bm_stddev = 0; +} diff --git a/kernel/trace/trace_benchmark.h b/kernel/trace/trace_benchmark.h new file mode 100644 index 000000000000..3c1df1df4e29 --- /dev/null +++ b/kernel/trace/trace_benchmark.h @@ -0,0 +1,41 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM benchmark + +#if !defined(_TRACE_BENCHMARK_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_BENCHMARK_H + +#include <linux/tracepoint.h> + +extern void trace_benchmark_reg(void); +extern void trace_benchmark_unreg(void); + +#define BENCHMARK_EVENT_STRLEN 128 + +TRACE_EVENT_FN(benchmark_event, + + TP_PROTO(const char *str), + + TP_ARGS(str), + + TP_STRUCT__entry( + __array( char, str, BENCHMARK_EVENT_STRLEN ) + ), + + TP_fast_assign( + memcpy(__entry->str, str, BENCHMARK_EVENT_STRLEN); + ), + + TP_printk("%s", __entry->str), + + trace_benchmark_reg, trace_benchmark_unreg +); + +#endif /* _TRACE_BENCHMARK_H */ + +#undef TRACE_INCLUDE_FILE +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#define TRACE_INCLUDE_FILE trace_benchmark + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index c894614de14d..5d12bb407b44 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -248,8 +248,8 @@ void perf_trace_del(struct perf_event *p_event, int flags) tp_event->class->reg(tp_event, TRACE_REG_PERF_DEL, p_event); } -__kprobes void *perf_trace_buf_prepare(int size, unsigned short type, - struct pt_regs *regs, int *rctxp) +void *perf_trace_buf_prepare(int size, unsigned short type, + struct pt_regs *regs, int *rctxp) { struct trace_entry *entry; unsigned long flags; @@ -281,6 +281,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, return raw_data; } EXPORT_SYMBOL_GPL(perf_trace_buf_prepare); +NOKPROBE_SYMBOL(perf_trace_buf_prepare); #ifdef CONFIG_FUNCTION_TRACER static void diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 3ddfd8f62c05..f99e0b3bca8c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -574,6 +574,9 @@ int trace_set_clr_event(const char *system, const char *event, int set) { struct trace_array *tr = top_trace_array(); + if (!tr) + return -ENODEV; + return __ftrace_set_clr_event(tr, NULL, system, event, set); } EXPORT_SYMBOL_GPL(trace_set_clr_event); @@ -2065,6 +2068,9 @@ event_enable_func(struct ftrace_hash *hash, bool enable; int ret; + if (!tr) + return -ENODEV; + /* hash funcs only work with set_ftrace_filter */ if (!enabled || !param) return -EINVAL; @@ -2396,6 +2402,9 @@ static __init int event_trace_enable(void) char *token; int ret; + if (!tr) + return -ENODEV; + for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) { call = *iter; @@ -2442,6 +2451,8 @@ static __init int event_trace_init(void) int ret; tr = top_trace_array(); + if (!tr) + return -ENODEV; d_tracer = tracing_init_dentry(); if (!d_tracer) @@ -2535,6 +2546,8 @@ static __init void event_trace_self_tests(void) int ret; tr = top_trace_array(); + if (!tr) + return; pr_info("Running tests on trace events:\n"); diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index ffd56351b521..57f0ec962d2c 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -26,8 +26,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip, static void function_stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *pt_regs); -static struct ftrace_ops trace_ops; -static struct ftrace_ops trace_stack_ops; static struct tracer_flags func_flags; /* Our option */ @@ -83,28 +81,24 @@ void ftrace_destroy_function_files(struct trace_array *tr) static int function_trace_init(struct trace_array *tr) { - struct ftrace_ops *ops; - - if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { - /* There's only one global tr */ - if (!trace_ops.private) { - trace_ops.private = tr; - trace_stack_ops.private = tr; - } + ftrace_func_t func; - if (func_flags.val & TRACE_FUNC_OPT_STACK) - ops = &trace_stack_ops; - else - ops = &trace_ops; - tr->ops = ops; - } else if (!tr->ops) { - /* - * Instance trace_arrays get their ops allocated - * at instance creation. Unless it failed - * the allocation. - */ + /* + * Instance trace_arrays get their ops allocated + * at instance creation. Unless it failed + * the allocation. + */ + if (!tr->ops) return -ENOMEM; - } + + /* Currently only the global instance can do stack tracing */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL && + func_flags.val & TRACE_FUNC_OPT_STACK) + func = function_stack_trace_call; + else + func = function_trace_call; + + ftrace_init_array_ops(tr, func); tr->trace_buffer.cpu = get_cpu(); put_cpu(); @@ -118,6 +112,7 @@ static void function_trace_reset(struct trace_array *tr) { tracing_stop_function_trace(tr); tracing_stop_cmdline_record(); + ftrace_reset_array_ops(tr); } static void function_trace_start(struct trace_array *tr) @@ -199,18 +194,6 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip, local_irq_restore(flags); } -static struct ftrace_ops trace_ops __read_mostly = -{ - .func = function_trace_call, - .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, -}; - -static struct ftrace_ops trace_stack_ops __read_mostly = -{ - .func = function_stack_trace_call, - .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, -}; - static struct tracer_opt func_opts[] = { #ifdef CONFIG_STACKTRACE { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, @@ -248,10 +231,10 @@ func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) unregister_ftrace_function(tr->ops); if (set) { - tr->ops = &trace_stack_ops; + tr->ops->func = function_stack_trace_call; register_ftrace_function(tr->ops); } else { - tr->ops = &trace_ops; + tr->ops->func = function_trace_call; register_ftrace_function(tr->ops); } @@ -269,7 +252,6 @@ static struct tracer function_trace __tracer_data = .init = function_trace_init, .reset = function_trace_reset, .start = function_trace_start, - .wait_pipe = poll_wait_pipe, .flags = &func_flags, .set_flag = func_set_flag, .allow_instances = true, diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index deff11200261..4de3e57f723c 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -38,15 +38,6 @@ struct fgraph_data { #define TRACE_GRAPH_INDENT 2 -/* Flag options */ -#define TRACE_GRAPH_PRINT_OVERRUN 0x1 -#define TRACE_GRAPH_PRINT_CPU 0x2 -#define TRACE_GRAPH_PRINT_OVERHEAD 0x4 -#define TRACE_GRAPH_PRINT_PROC 0x8 -#define TRACE_GRAPH_PRINT_DURATION 0x10 -#define TRACE_GRAPH_PRINT_ABS_TIME 0x20 -#define TRACE_GRAPH_PRINT_IRQS 0x40 - static unsigned int max_depth; static struct tracer_opt trace_opts[] = { @@ -64,11 +55,13 @@ static struct tracer_opt trace_opts[] = { { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, /* Display interrupts */ { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) }, + /* Display function name after trailing } */ + { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) }, { } /* Empty entry */ }; static struct tracer_flags tracer_flags = { - /* Don't display overruns and proc by default */ + /* Don't display overruns, proc, or tail by default */ .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD | TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS, .opts = trace_opts @@ -1176,9 +1169,10 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, * If the return function does not have a matching entry, * then the entry was lost. Instead of just printing * the '}' and letting the user guess what function this - * belongs to, write out the function name. + * belongs to, write out the function name. Always do + * that if the funcgraph-tail option is enabled. */ - if (func_match) { + if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) { ret = trace_seq_puts(s, "}\n"); if (!ret) return TRACE_TYPE_PARTIAL_LINE; @@ -1505,7 +1499,6 @@ static struct tracer graph_trace __tracer_data = { .pipe_open = graph_trace_open, .close = graph_trace_close, .pipe_close = graph_trace_close, - .wait_pipe = poll_wait_pipe, .init = graph_trace_init, .reset = graph_trace_reset, .print_line = print_graph_function, diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 8ff02cbb892f..9bb104f748d0 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -151,12 +151,6 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, atomic_dec(&data->disabled); } - -static struct ftrace_ops trace_ops __read_mostly = -{ - .func = irqsoff_tracer_call, - .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, -}; #endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -176,7 +170,7 @@ irqsoff_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) for_each_possible_cpu(cpu) per_cpu(tracing_cpu, cpu) = 0; - tracing_max_latency = 0; + tr->max_latency = 0; tracing_reset_online_cpus(&irqsoff_trace->trace_buffer); return start_irqsoff_tracer(irqsoff_trace, set); @@ -303,13 +297,13 @@ static void irqsoff_print_header(struct seq_file *s) /* * Should this new latency be reported/recorded? */ -static int report_latency(cycle_t delta) +static int report_latency(struct trace_array *tr, cycle_t delta) { if (tracing_thresh) { if (delta < tracing_thresh) return 0; } else { - if (delta <= tracing_max_latency) + if (delta <= tr->max_latency) return 0; } return 1; @@ -333,13 +327,13 @@ check_critical_timing(struct trace_array *tr, pc = preempt_count(); - if (!report_latency(delta)) + if (!report_latency(tr, delta)) goto out; raw_spin_lock_irqsave(&max_trace_lock, flags); /* check if we are still the max latency */ - if (!report_latency(delta)) + if (!report_latency(tr, delta)) goto out_unlock; __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); @@ -352,7 +346,7 @@ check_critical_timing(struct trace_array *tr, data->critical_end = parent_ip; if (likely(!is_tracing_stopped())) { - tracing_max_latency = delta; + tr->max_latency = delta; update_max_tr_single(tr, current, cpu); } @@ -531,7 +525,7 @@ void trace_preempt_off(unsigned long a0, unsigned long a1) } #endif /* CONFIG_PREEMPT_TRACER */ -static int register_irqsoff_function(int graph, int set) +static int register_irqsoff_function(struct trace_array *tr, int graph, int set) { int ret; @@ -543,7 +537,7 @@ static int register_irqsoff_function(int graph, int set) ret = register_ftrace_graph(&irqsoff_graph_return, &irqsoff_graph_entry); else - ret = register_ftrace_function(&trace_ops); + ret = register_ftrace_function(tr->ops); if (!ret) function_enabled = true; @@ -551,7 +545,7 @@ static int register_irqsoff_function(int graph, int set) return ret; } -static void unregister_irqsoff_function(int graph) +static void unregister_irqsoff_function(struct trace_array *tr, int graph) { if (!function_enabled) return; @@ -559,17 +553,17 @@ static void unregister_irqsoff_function(int graph) if (graph) unregister_ftrace_graph(); else - unregister_ftrace_function(&trace_ops); + unregister_ftrace_function(tr->ops); function_enabled = false; } -static void irqsoff_function_set(int set) +static void irqsoff_function_set(struct trace_array *tr, int set) { if (set) - register_irqsoff_function(is_graph(), 1); + register_irqsoff_function(tr, is_graph(), 1); else - unregister_irqsoff_function(is_graph()); + unregister_irqsoff_function(tr, is_graph()); } static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set) @@ -577,7 +571,7 @@ static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set) struct tracer *tracer = tr->current_trace; if (mask & TRACE_ITER_FUNCTION) - irqsoff_function_set(set); + irqsoff_function_set(tr, set); return trace_keep_overwrite(tracer, mask, set); } @@ -586,7 +580,7 @@ static int start_irqsoff_tracer(struct trace_array *tr, int graph) { int ret; - ret = register_irqsoff_function(graph, 0); + ret = register_irqsoff_function(tr, graph, 0); if (!ret && tracing_is_enabled()) tracer_enabled = 1; @@ -600,25 +594,37 @@ static void stop_irqsoff_tracer(struct trace_array *tr, int graph) { tracer_enabled = 0; - unregister_irqsoff_function(graph); + unregister_irqsoff_function(tr, graph); } -static void __irqsoff_tracer_init(struct trace_array *tr) +static bool irqsoff_busy; + +static int __irqsoff_tracer_init(struct trace_array *tr) { + if (irqsoff_busy) + return -EBUSY; + save_flags = trace_flags; /* non overwrite screws up the latency tracers */ set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); - tracing_max_latency = 0; + tr->max_latency = 0; irqsoff_trace = tr; /* make sure that the tracer is visible */ smp_wmb(); tracing_reset_online_cpus(&tr->trace_buffer); - if (start_irqsoff_tracer(tr, is_graph())) + ftrace_init_array_ops(tr, irqsoff_tracer_call); + + /* Only toplevel instance supports graph tracing */ + if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL && + is_graph()))) printk(KERN_ERR "failed to start irqsoff tracer\n"); + + irqsoff_busy = true; + return 0; } static void irqsoff_tracer_reset(struct trace_array *tr) @@ -630,6 +636,9 @@ static void irqsoff_tracer_reset(struct trace_array *tr) set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); + ftrace_reset_array_ops(tr); + + irqsoff_busy = false; } static void irqsoff_tracer_start(struct trace_array *tr) @@ -647,8 +656,7 @@ static int irqsoff_tracer_init(struct trace_array *tr) { trace_type = TRACER_IRQS_OFF; - __irqsoff_tracer_init(tr); - return 0; + return __irqsoff_tracer_init(tr); } static struct tracer irqsoff_tracer __read_mostly = { @@ -668,6 +676,7 @@ static struct tracer irqsoff_tracer __read_mostly = #endif .open = irqsoff_trace_open, .close = irqsoff_trace_close, + .allow_instances = true, .use_max_tr = true, }; # define register_irqsoff(trace) register_tracer(&trace) @@ -680,8 +689,7 @@ static int preemptoff_tracer_init(struct trace_array *tr) { trace_type = TRACER_PREEMPT_OFF; - __irqsoff_tracer_init(tr); - return 0; + return __irqsoff_tracer_init(tr); } static struct tracer preemptoff_tracer __read_mostly = @@ -702,6 +710,7 @@ static struct tracer preemptoff_tracer __read_mostly = #endif .open = irqsoff_trace_open, .close = irqsoff_trace_close, + .allow_instances = true, .use_max_tr = true, }; # define register_preemptoff(trace) register_tracer(&trace) @@ -716,8 +725,7 @@ static int preemptirqsoff_tracer_init(struct trace_array *tr) { trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; - __irqsoff_tracer_init(tr); - return 0; + return __irqsoff_tracer_init(tr); } static struct tracer preemptirqsoff_tracer __read_mostly = @@ -738,6 +746,7 @@ static struct tracer preemptirqsoff_tracer __read_mostly = #endif .open = irqsoff_trace_open, .close = irqsoff_trace_close, + .allow_instances = true, .use_max_tr = true, }; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 903ae28962be..282f6e4e5539 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -40,27 +40,27 @@ struct trace_kprobe { (sizeof(struct probe_arg) * (n))) -static __kprobes bool trace_kprobe_is_return(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) { return tk->rp.handler != NULL; } -static __kprobes const char *trace_kprobe_symbol(struct trace_kprobe *tk) +static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) { return tk->symbol ? tk->symbol : "unknown"; } -static __kprobes unsigned long trace_kprobe_offset(struct trace_kprobe *tk) +static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) { return tk->rp.kp.offset; } -static __kprobes bool trace_kprobe_has_gone(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) { return !!(kprobe_gone(&tk->rp.kp)); } -static __kprobes bool trace_kprobe_within_module(struct trace_kprobe *tk, +static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, struct module *mod) { int len = strlen(mod->name); @@ -68,7 +68,7 @@ static __kprobes bool trace_kprobe_within_module(struct trace_kprobe *tk, return strncmp(mod->name, name, len) == 0 && name[len] == ':'; } -static __kprobes bool trace_kprobe_is_on_module(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) { return !!strchr(trace_kprobe_symbol(tk), ':'); } @@ -132,19 +132,21 @@ struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) * Kprobes-specific fetch functions */ #define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ +static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ void *offset, void *dest) \ { \ *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ (unsigned int)((unsigned long)offset)); \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); + DEFINE_BASIC_FETCH_FUNCS(stack) /* No string on the stack entry */ #define fetch_stack_string NULL #define fetch_stack_string_size NULL #define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ +static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ void *addr, void *dest) \ { \ type retval; \ @@ -152,14 +154,16 @@ static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ *(type *)dest = 0; \ else \ *(type *)dest = retval; \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); + DEFINE_BASIC_FETCH_FUNCS(memory) /* * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */ -static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) +static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) { long ret; int maxlen = get_rloc_len(*(u32 *)dest); @@ -193,10 +197,11 @@ static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, get_rloc_offs(*(u32 *)dest)); } } +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); /* Return the length of string -- including null terminal byte */ -static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) +static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) { mm_segment_t old_fs; int ret, len = 0; @@ -219,17 +224,19 @@ static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, else *(u32 *)dest = len; } +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); #define DEFINE_FETCH_symbol(type) \ -__kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \ - void *data, void *dest) \ +void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ { \ struct symbol_cache *sc = data; \ if (sc->addr) \ fetch_memory_##type(regs, (void *)sc->addr, dest); \ else \ *(type *)dest = 0; \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); + DEFINE_BASIC_FETCH_FUNCS(symbol) DEFINE_FETCH_symbol(string) DEFINE_FETCH_symbol(string_size) @@ -907,7 +914,7 @@ static const struct file_operations kprobe_profile_ops = { }; /* Kprobe handler */ -static __kprobes void +static nokprobe_inline void __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, struct ftrace_event_file *ftrace_file) { @@ -943,7 +950,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, entry, irq_flags, pc, regs); } -static __kprobes void +static void kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) { struct event_file_link *link; @@ -951,9 +958,10 @@ kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) list_for_each_entry_rcu(link, &tk->tp.files, list) __kprobe_trace_func(tk, regs, link->file); } +NOKPROBE_SYMBOL(kprobe_trace_func); /* Kretprobe handler */ -static __kprobes void +static nokprobe_inline void __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct pt_regs *regs, struct ftrace_event_file *ftrace_file) @@ -991,7 +999,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, entry, irq_flags, pc, regs); } -static __kprobes void +static void kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct pt_regs *regs) { @@ -1000,6 +1008,7 @@ kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, list_for_each_entry_rcu(link, &tk->tp.files, list) __kretprobe_trace_func(tk, ri, regs, link->file); } +NOKPROBE_SYMBOL(kretprobe_trace_func); /* Event entry printers */ static enum print_line_t @@ -1131,7 +1140,7 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) #ifdef CONFIG_PERF_EVENTS /* Kprobe profile handler */ -static __kprobes void +static void kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) { struct ftrace_event_call *call = &tk->tp.call; @@ -1158,9 +1167,10 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); } +NOKPROBE_SYMBOL(kprobe_perf_func); /* Kretprobe profile handler */ -static __kprobes void +static void kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct pt_regs *regs) { @@ -1188,6 +1198,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); } +NOKPROBE_SYMBOL(kretprobe_perf_func); #endif /* CONFIG_PERF_EVENTS */ /* @@ -1196,9 +1207,8 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe * lockless, but we can't race with this __init function. */ -static __kprobes -int kprobe_register(struct ftrace_event_call *event, - enum trace_reg type, void *data) +static int kprobe_register(struct ftrace_event_call *event, + enum trace_reg type, void *data) { struct trace_kprobe *tk = (struct trace_kprobe *)event->data; struct ftrace_event_file *file = data; @@ -1224,8 +1234,7 @@ int kprobe_register(struct ftrace_event_call *event, return 0; } -static __kprobes -int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) +static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) { struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); @@ -1239,9 +1248,10 @@ int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) #endif return 0; /* We don't tweek kernel, so just return 0 */ } +NOKPROBE_SYMBOL(kprobe_dispatcher); -static __kprobes -int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) +static int +kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) { struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); @@ -1255,6 +1265,7 @@ int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) #endif return 0; /* We don't tweek kernel, so just return 0 */ } +NOKPROBE_SYMBOL(kretprobe_dispatcher); static struct trace_event_functions kretprobe_funcs = { .trace = print_kretprobe_event @@ -1377,6 +1388,9 @@ static __init int kprobe_trace_self_tests_init(void) struct trace_kprobe *tk; struct ftrace_event_file *file; + if (tracing_is_disabled()) + return -ENODEV; + target = kprobe_trace_selftest_target; pr_info("Testing kprobe tracing: "); diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c index 69a5cc94c01a..fcf0a9e48916 100644 --- a/kernel/trace/trace_nop.c +++ b/kernel/trace/trace_nop.c @@ -91,7 +91,6 @@ struct tracer nop_trace __read_mostly = .name = "nop", .init = nop_trace_init, .reset = nop_trace_reset, - .wait_pipe = poll_wait_pipe, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_nop, #endif diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index a436de18aa99..f3dad80c20b2 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -126,6 +126,34 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) EXPORT_SYMBOL_GPL(trace_seq_printf); /** + * trace_seq_bitmask - put a list of longs as a bitmask print output + * @s: trace sequence descriptor + * @maskp: points to an array of unsigned longs that represent a bitmask + * @nmaskbits: The number of bits that are valid in @maskp + * + * It returns 0 if the trace oversizes the buffer's free + * space, 1 otherwise. + * + * Writes a ASCII representation of a bitmask string into @s. + */ +int +trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, + int nmaskbits) +{ + int len = (PAGE_SIZE - 1) - s->len; + int ret; + + if (s->full || !len) + return 0; + + ret = bitmap_scnprintf(s->buffer, len, maskp, nmaskbits); + s->len += ret; + + return 1; +} +EXPORT_SYMBOL_GPL(trace_seq_bitmask); + +/** * trace_seq_vprintf - sequence printing of trace information * @s: trace sequence descriptor * @fmt: printf format string @@ -399,6 +427,19 @@ EXPORT_SYMBOL(ftrace_print_symbols_seq_u64); #endif const char * +ftrace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr, + unsigned int bitmask_size) +{ + const char *ret = p->buffer + p->len; + + trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8); + trace_seq_putc(p, 0); + + return ret; +} +EXPORT_SYMBOL_GPL(ftrace_print_bitmask_seq); + +const char * ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len) { int i; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8364a421b4df..d4b9fc22cd27 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -37,13 +37,13 @@ const char *reserved_field_names[] = { /* Printing in basic type function template */ #define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt) \ -__kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent) \ +int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ + void *data, void *ent) \ { \ return trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \ } \ -const char PRINT_TYPE_FMT_NAME(type)[] = fmt; +const char PRINT_TYPE_FMT_NAME(type)[] = fmt; \ +NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type)); DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x") @@ -55,9 +55,8 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d") DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld") /* Print type function for string type */ -__kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, - const char *name, - void *data, void *ent) +int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name, + void *data, void *ent) { int len = *(u32 *)data >> 16; @@ -67,6 +66,7 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, return trace_seq_printf(s, " %s=\"%s\"", name, (const char *)get_loc_data(data, ent)); } +NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string)); const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; @@ -81,23 +81,24 @@ const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; /* Data fetch function templates */ #define DEFINE_FETCH_reg(type) \ -__kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ +void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \ { \ *(type *)dest = (type)regs_get_register(regs, \ (unsigned int)((unsigned long)offset)); \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type)); DEFINE_BASIC_FETCH_FUNCS(reg) /* No string on the register */ #define fetch_reg_string NULL #define fetch_reg_string_size NULL #define DEFINE_FETCH_retval(type) \ -__kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ - void *dummy, void *dest) \ +void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ + void *dummy, void *dest) \ { \ *(type *)dest = (type)regs_return_value(regs); \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type)); DEFINE_BASIC_FETCH_FUNCS(retval) /* No string on the retval */ #define fetch_retval_string NULL @@ -112,8 +113,8 @@ struct deref_fetch_param { }; #define DEFINE_FETCH_deref(type) \ -__kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ - void *data, void *dest) \ +void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ + void *data, void *dest) \ { \ struct deref_fetch_param *dprm = data; \ unsigned long addr; \ @@ -123,12 +124,13 @@ __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ dprm->fetch(regs, (void *)addr, dest); \ } else \ *(type *)dest = 0; \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type)); DEFINE_BASIC_FETCH_FUNCS(deref) DEFINE_FETCH_deref(string) -__kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, - void *data, void *dest) +void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, + void *data, void *dest) { struct deref_fetch_param *dprm = data; unsigned long addr; @@ -140,16 +142,18 @@ __kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, } else *(string_size *)dest = 0; } +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size)); -static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) +static void update_deref_fetch_param(struct deref_fetch_param *data) { if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) update_deref_fetch_param(data->orig.data); else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) update_symbol_cache(data->orig.data); } +NOKPROBE_SYMBOL(update_deref_fetch_param); -static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) +static void free_deref_fetch_param(struct deref_fetch_param *data) { if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) free_deref_fetch_param(data->orig.data); @@ -157,6 +161,7 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) free_symbol_cache(data->orig.data); kfree(data); } +NOKPROBE_SYMBOL(free_deref_fetch_param); /* Bitfield fetch function */ struct bitfield_fetch_param { @@ -166,8 +171,8 @@ struct bitfield_fetch_param { }; #define DEFINE_FETCH_bitfield(type) \ -__kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ - void *data, void *dest) \ +void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ + void *data, void *dest) \ { \ struct bitfield_fetch_param *bprm = data; \ type buf = 0; \ @@ -177,13 +182,13 @@ __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ buf >>= bprm->low_shift; \ } \ *(type *)dest = buf; \ -} - +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type)); DEFINE_BASIC_FETCH_FUNCS(bitfield) #define fetch_bitfield_string NULL #define fetch_bitfield_string_size NULL -static __kprobes void +static void update_bitfield_fetch_param(struct bitfield_fetch_param *data) { /* @@ -196,7 +201,7 @@ update_bitfield_fetch_param(struct bitfield_fetch_param *data) update_symbol_cache(data->orig.data); } -static __kprobes void +static void free_bitfield_fetch_param(struct bitfield_fetch_param *data) { /* @@ -255,17 +260,17 @@ fail: } /* Special function : only accept unsigned long */ -static __kprobes void fetch_kernel_stack_address(struct pt_regs *regs, - void *dummy, void *dest) +static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest) { *(unsigned long *)dest = kernel_stack_pointer(regs); } +NOKPROBE_SYMBOL(fetch_kernel_stack_address); -static __kprobes void fetch_user_stack_address(struct pt_regs *regs, - void *dummy, void *dest) +static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest) { *(unsigned long *)dest = user_stack_pointer(regs); } +NOKPROBE_SYMBOL(fetch_user_stack_address); static fetch_func_t get_fetch_size_function(const struct fetch_type *type, fetch_func_t orig_fn, diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index fb1ab5dfbd42..4f815fbce16d 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -81,13 +81,13 @@ */ #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) -static inline void *get_rloc_data(u32 *dl) +static nokprobe_inline void *get_rloc_data(u32 *dl) { return (u8 *)dl + get_rloc_offs(*dl); } /* For data_loc conversion */ -static inline void *get_loc_data(u32 *dl, void *ent) +static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) { return (u8 *)ent + get_rloc_offs(*dl); } @@ -136,9 +136,8 @@ typedef u32 string_size; /* Printing in basic type function template */ #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ -__kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent); \ +int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ + void *data, void *ent); \ extern const char PRINT_TYPE_FMT_NAME(type)[] DECLARE_BASIC_PRINT_TYPE_FUNC(u8); @@ -303,7 +302,7 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp) return !!(tp->flags & TP_FLAG_REGISTERED); } -static inline __kprobes void call_fetch(struct fetch_param *fprm, +static nokprobe_inline void call_fetch(struct fetch_param *fprm, struct pt_regs *regs, void *dest) { return fprm->fn(regs, fprm->data, dest); @@ -351,7 +350,7 @@ extern ssize_t traceprobe_probes_write(struct file *file, extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); /* Sum up total data length for dynamic arraies (strings) */ -static inline __kprobes int +static nokprobe_inline int __get_data_size(struct trace_probe *tp, struct pt_regs *regs) { int i, ret = 0; @@ -367,7 +366,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs) } /* Store the value of each argument */ -static inline __kprobes void +static nokprobe_inline void store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, u8 *data, int maxlen) { diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index e14da5e97a69..19bd8928ce94 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -130,15 +130,9 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, atomic_dec(&data->disabled); preempt_enable_notrace(); } - -static struct ftrace_ops trace_ops __read_mostly = -{ - .func = wakeup_tracer_call, - .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, -}; #endif /* CONFIG_FUNCTION_TRACER */ -static int register_wakeup_function(int graph, int set) +static int register_wakeup_function(struct trace_array *tr, int graph, int set) { int ret; @@ -150,7 +144,7 @@ static int register_wakeup_function(int graph, int set) ret = register_ftrace_graph(&wakeup_graph_return, &wakeup_graph_entry); else - ret = register_ftrace_function(&trace_ops); + ret = register_ftrace_function(tr->ops); if (!ret) function_enabled = true; @@ -158,7 +152,7 @@ static int register_wakeup_function(int graph, int set) return ret; } -static void unregister_wakeup_function(int graph) +static void unregister_wakeup_function(struct trace_array *tr, int graph) { if (!function_enabled) return; @@ -166,17 +160,17 @@ static void unregister_wakeup_function(int graph) if (graph) unregister_ftrace_graph(); else - unregister_ftrace_function(&trace_ops); + unregister_ftrace_function(tr->ops); function_enabled = false; } -static void wakeup_function_set(int set) +static void wakeup_function_set(struct trace_array *tr, int set) { if (set) - register_wakeup_function(is_graph(), 1); + register_wakeup_function(tr, is_graph(), 1); else - unregister_wakeup_function(is_graph()); + unregister_wakeup_function(tr, is_graph()); } static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) @@ -184,16 +178,16 @@ static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) struct tracer *tracer = tr->current_trace; if (mask & TRACE_ITER_FUNCTION) - wakeup_function_set(set); + wakeup_function_set(tr, set); return trace_keep_overwrite(tracer, mask, set); } -static int start_func_tracer(int graph) +static int start_func_tracer(struct trace_array *tr, int graph) { int ret; - ret = register_wakeup_function(graph, 0); + ret = register_wakeup_function(tr, graph, 0); if (!ret && tracing_is_enabled()) tracer_enabled = 1; @@ -203,11 +197,11 @@ static int start_func_tracer(int graph) return ret; } -static void stop_func_tracer(int graph) +static void stop_func_tracer(struct trace_array *tr, int graph) { tracer_enabled = 0; - unregister_wakeup_function(graph); + unregister_wakeup_function(tr, graph); } #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -221,12 +215,12 @@ wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) if (!(is_graph() ^ set)) return 0; - stop_func_tracer(!set); + stop_func_tracer(tr, !set); wakeup_reset(wakeup_trace); - tracing_max_latency = 0; + tr->max_latency = 0; - return start_func_tracer(set); + return start_func_tracer(tr, set); } static int wakeup_graph_entry(struct ftrace_graph_ent *trace) @@ -350,13 +344,13 @@ static void wakeup_print_header(struct seq_file *s) /* * Should this new latency be reported/recorded? */ -static int report_latency(cycle_t delta) +static int report_latency(struct trace_array *tr, cycle_t delta) { if (tracing_thresh) { if (delta < tracing_thresh) return 0; } else { - if (delta <= tracing_max_latency) + if (delta <= tr->max_latency) return 0; } return 1; @@ -424,11 +418,11 @@ probe_wakeup_sched_switch(void *ignore, T1 = ftrace_now(cpu); delta = T1-T0; - if (!report_latency(delta)) + if (!report_latency(wakeup_trace, delta)) goto out_unlock; if (likely(!is_tracing_stopped())) { - tracing_max_latency = delta; + wakeup_trace->max_latency = delta; update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); } @@ -587,7 +581,7 @@ static void start_wakeup_tracer(struct trace_array *tr) */ smp_wmb(); - if (start_func_tracer(is_graph())) + if (start_func_tracer(tr, is_graph())) printk(KERN_ERR "failed to start wakeup tracer\n"); return; @@ -600,13 +594,15 @@ fail_deprobe: static void stop_wakeup_tracer(struct trace_array *tr) { tracer_enabled = 0; - stop_func_tracer(is_graph()); + stop_func_tracer(tr, is_graph()); unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); unregister_trace_sched_wakeup_new(probe_wakeup, NULL); unregister_trace_sched_wakeup(probe_wakeup, NULL); unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); } +static bool wakeup_busy; + static int __wakeup_tracer_init(struct trace_array *tr) { save_flags = trace_flags; @@ -615,14 +611,20 @@ static int __wakeup_tracer_init(struct trace_array *tr) set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); - tracing_max_latency = 0; + tr->max_latency = 0; wakeup_trace = tr; + ftrace_init_array_ops(tr, wakeup_tracer_call); start_wakeup_tracer(tr); + + wakeup_busy = true; return 0; } static int wakeup_tracer_init(struct trace_array *tr) { + if (wakeup_busy) + return -EBUSY; + wakeup_dl = 0; wakeup_rt = 0; return __wakeup_tracer_init(tr); @@ -630,6 +632,9 @@ static int wakeup_tracer_init(struct trace_array *tr) static int wakeup_rt_tracer_init(struct trace_array *tr) { + if (wakeup_busy) + return -EBUSY; + wakeup_dl = 0; wakeup_rt = 1; return __wakeup_tracer_init(tr); @@ -637,6 +642,9 @@ static int wakeup_rt_tracer_init(struct trace_array *tr) static int wakeup_dl_tracer_init(struct trace_array *tr) { + if (wakeup_busy) + return -EBUSY; + wakeup_dl = 1; wakeup_rt = 0; return __wakeup_tracer_init(tr); @@ -653,6 +661,8 @@ static void wakeup_tracer_reset(struct trace_array *tr) set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); + ftrace_reset_array_ops(tr); + wakeup_busy = false; } static void wakeup_tracer_start(struct trace_array *tr) @@ -684,6 +694,7 @@ static struct tracer wakeup_tracer __read_mostly = #endif .open = wakeup_trace_open, .close = wakeup_trace_close, + .allow_instances = true, .use_max_tr = true, }; @@ -694,7 +705,6 @@ static struct tracer wakeup_rt_tracer __read_mostly = .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, .stop = wakeup_tracer_stop, - .wait_pipe = poll_wait_pipe, .print_max = true, .print_header = wakeup_print_header, .print_line = wakeup_print_line, @@ -706,6 +716,7 @@ static struct tracer wakeup_rt_tracer __read_mostly = #endif .open = wakeup_trace_open, .close = wakeup_trace_close, + .allow_instances = true, .use_max_tr = true, }; @@ -716,7 +727,6 @@ static struct tracer wakeup_dl_tracer __read_mostly = .reset = wakeup_tracer_reset, .start = wakeup_tracer_start, .stop = wakeup_tracer_stop, - .wait_pipe = poll_wait_pipe, .print_max = true, .print_header = wakeup_print_header, .print_line = wakeup_print_line, diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index e98fca60974f..5ef60499dc8e 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -65,7 +65,7 @@ static int trace_test_buffer(struct trace_buffer *buf, unsigned long *count) /* Don't allow flipping of max traces now */ local_irq_save(flags); - arch_spin_lock(&ftrace_max_lock); + arch_spin_lock(&buf->tr->max_lock); cnt = ring_buffer_entries(buf->buffer); @@ -83,7 +83,7 @@ static int trace_test_buffer(struct trace_buffer *buf, unsigned long *count) break; } tracing_on(); - arch_spin_unlock(&ftrace_max_lock); + arch_spin_unlock(&buf->tr->max_lock); local_irq_restore(flags); if (count) @@ -161,11 +161,6 @@ static struct ftrace_ops test_probe3 = { .flags = FTRACE_OPS_FL_RECURSION_SAFE, }; -static struct ftrace_ops test_global = { - .func = trace_selftest_test_global_func, - .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, -}; - static void print_counts(void) { printk("(%d %d %d %d %d) ", @@ -185,7 +180,7 @@ static void reset_counts(void) trace_selftest_test_dyn_cnt = 0; } -static int trace_selftest_ops(int cnt) +static int trace_selftest_ops(struct trace_array *tr, int cnt) { int save_ftrace_enabled = ftrace_enabled; struct ftrace_ops *dyn_ops; @@ -220,7 +215,11 @@ static int trace_selftest_ops(int cnt) register_ftrace_function(&test_probe1); register_ftrace_function(&test_probe2); register_ftrace_function(&test_probe3); - register_ftrace_function(&test_global); + /* First time we are running with main function */ + if (cnt > 1) { + ftrace_init_array_ops(tr, trace_selftest_test_global_func); + register_ftrace_function(tr->ops); + } DYN_FTRACE_TEST_NAME(); @@ -232,8 +231,10 @@ static int trace_selftest_ops(int cnt) goto out; if (trace_selftest_test_probe3_cnt != 1) goto out; - if (trace_selftest_test_global_cnt == 0) - goto out; + if (cnt > 1) { + if (trace_selftest_test_global_cnt == 0) + goto out; + } DYN_FTRACE_TEST_NAME2(); @@ -269,8 +270,10 @@ static int trace_selftest_ops(int cnt) goto out_free; if (trace_selftest_test_probe3_cnt != 3) goto out_free; - if (trace_selftest_test_global_cnt == 0) - goto out; + if (cnt > 1) { + if (trace_selftest_test_global_cnt == 0) + goto out; + } if (trace_selftest_test_dyn_cnt == 0) goto out_free; @@ -295,7 +298,9 @@ static int trace_selftest_ops(int cnt) unregister_ftrace_function(&test_probe1); unregister_ftrace_function(&test_probe2); unregister_ftrace_function(&test_probe3); - unregister_ftrace_function(&test_global); + if (cnt > 1) + unregister_ftrace_function(tr->ops); + ftrace_reset_array_ops(tr); /* Make sure everything is off */ reset_counts(); @@ -315,9 +320,9 @@ static int trace_selftest_ops(int cnt) } /* Test dynamic code modification and ftrace filters */ -int trace_selftest_startup_dynamic_tracing(struct tracer *trace, - struct trace_array *tr, - int (*func)(void)) +static int trace_selftest_startup_dynamic_tracing(struct tracer *trace, + struct trace_array *tr, + int (*func)(void)) { int save_ftrace_enabled = ftrace_enabled; unsigned long count; @@ -388,7 +393,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, } /* Test the ops with global tracing running */ - ret = trace_selftest_ops(1); + ret = trace_selftest_ops(tr, 1); trace->reset(tr); out: @@ -399,7 +404,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, /* Test the ops with global tracing off */ if (!ret) - ret = trace_selftest_ops(2); + ret = trace_selftest_ops(tr, 2); return ret; } @@ -802,7 +807,7 @@ out: int trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) { - unsigned long save_max = tracing_max_latency; + unsigned long save_max = tr->max_latency; unsigned long count; int ret; @@ -814,7 +819,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) } /* reset the max latency */ - tracing_max_latency = 0; + tr->max_latency = 0; /* disable interrupts for a bit */ local_irq_disable(); udelay(100); @@ -841,7 +846,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) ret = -1; } - tracing_max_latency = save_max; + tr->max_latency = save_max; return ret; } @@ -851,7 +856,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr) int trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) { - unsigned long save_max = tracing_max_latency; + unsigned long save_max = tr->max_latency; unsigned long count; int ret; @@ -876,7 +881,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) } /* reset the max latency */ - tracing_max_latency = 0; + tr->max_latency = 0; /* disable preemption for a bit */ preempt_disable(); udelay(100); @@ -903,7 +908,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) ret = -1; } - tracing_max_latency = save_max; + tr->max_latency = save_max; return ret; } @@ -913,7 +918,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr) int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr) { - unsigned long save_max = tracing_max_latency; + unsigned long save_max = tr->max_latency; unsigned long count; int ret; @@ -938,7 +943,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * } /* reset the max latency */ - tracing_max_latency = 0; + tr->max_latency = 0; /* disable preemption and interrupts for a bit */ preempt_disable(); @@ -973,7 +978,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * } /* do the test by disabling interrupts first this time */ - tracing_max_latency = 0; + tr->max_latency = 0; tracing_start(); trace->start(tr); @@ -1004,7 +1009,7 @@ out: tracing_start(); out_no_start: trace->reset(tr); - tracing_max_latency = save_max; + tr->max_latency = save_max; return ret; } @@ -1057,7 +1062,7 @@ static int trace_wakeup_test_thread(void *data) int trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) { - unsigned long save_max = tracing_max_latency; + unsigned long save_max = tr->max_latency; struct task_struct *p; struct completion is_ready; unsigned long count; @@ -1083,7 +1088,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) } /* reset the max latency */ - tracing_max_latency = 0; + tr->max_latency = 0; while (p->on_rq) { /* @@ -1113,7 +1118,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) trace->reset(tr); tracing_start(); - tracing_max_latency = save_max; + tr->max_latency = save_max; /* kill the thread */ kthread_stop(p); diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 21b320e5d163..8a4e5cb66a4c 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -51,11 +51,33 @@ static DEFINE_MUTEX(stack_sysctl_mutex); int stack_tracer_enabled; static int last_stack_tracer_enabled; +static inline void print_max_stack(void) +{ + long i; + int size; + + pr_emerg(" Depth Size Location (%d entries)\n" + " ----- ---- --------\n", + max_stack_trace.nr_entries - 1); + + for (i = 0; i < max_stack_trace.nr_entries; i++) { + if (stack_dump_trace[i] == ULONG_MAX) + break; + if (i+1 == max_stack_trace.nr_entries || + stack_dump_trace[i+1] == ULONG_MAX) + size = stack_dump_index[i]; + else + size = stack_dump_index[i] - stack_dump_index[i+1]; + + pr_emerg("%3ld) %8d %5d %pS\n", i, stack_dump_index[i], + size, (void *)stack_dump_trace[i]); + } +} + static inline void check_stack(unsigned long ip, unsigned long *stack) { - unsigned long this_size, flags; - unsigned long *p, *top, *start; + unsigned long this_size, flags; unsigned long *p, *top, *start; static int tracer_frame; int frame_size = ACCESS_ONCE(tracer_frame); int i; @@ -85,8 +107,12 @@ check_stack(unsigned long ip, unsigned long *stack) max_stack_size = this_size; - max_stack_trace.nr_entries = 0; - max_stack_trace.skip = 3; + max_stack_trace.nr_entries = 0; + + if (using_ftrace_ops_list_func()) + max_stack_trace.skip = 4; + else + max_stack_trace.skip = 3; save_stack_trace(&max_stack_trace); @@ -145,8 +171,12 @@ check_stack(unsigned long ip, unsigned long *stack) i++; } - BUG_ON(current != &init_task && - *(end_of_stack(current)) != STACK_END_MAGIC); + if ((current != &init_task && + *(end_of_stack(current)) != STACK_END_MAGIC)) { + print_max_stack(); + BUG(); + } + out: arch_spin_unlock(&max_stack_lock); local_irq_restore(flags); diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index c082a7441345..3c9b97e6b1f4 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -108,8 +108,8 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) * Uprobes-specific fetch functions */ #define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ +static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ + void *offset, void *dest) \ { \ *(type *)dest = (type)get_user_stack_nth(regs, \ ((unsigned long)offset)); \ @@ -120,8 +120,8 @@ DEFINE_BASIC_FETCH_FUNCS(stack) #define fetch_stack_string_size NULL #define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ - void *addr, void *dest) \ +static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ + void *addr, void *dest) \ { \ type retval; \ void __user *vaddr = (void __force __user *) addr; \ @@ -136,8 +136,8 @@ DEFINE_BASIC_FETCH_FUNCS(memory) * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */ -static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) +static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) { long ret; u32 rloc = *(u32 *)dest; @@ -158,8 +158,8 @@ static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, } } -static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) +static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) { int len; void __user *vaddr = (void __force __user *) addr; @@ -184,8 +184,8 @@ static unsigned long translate_user_vaddr(void *file_offset) } #define DEFINE_FETCH_file_offset(type) \ -static __kprobes void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ +static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \ + void *offset, void *dest)\ { \ void *vaddr = (void *)translate_user_vaddr(offset); \ \ @@ -893,6 +893,9 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file, int ret; if (file) { + if (tu->tp.flags & TP_FLAG_PROFILE) + return -EINTR; + link = kmalloc(sizeof(*link), GFP_KERNEL); if (!link) return -ENOMEM; @@ -901,29 +904,40 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file, list_add_tail_rcu(&link->list, &tu->tp.files); tu->tp.flags |= TP_FLAG_TRACE; - } else - tu->tp.flags |= TP_FLAG_PROFILE; + } else { + if (tu->tp.flags & TP_FLAG_TRACE) + return -EINTR; - ret = uprobe_buffer_enable(); - if (ret < 0) - return ret; + tu->tp.flags |= TP_FLAG_PROFILE; + } WARN_ON(!uprobe_filter_is_empty(&tu->filter)); if (enabled) return 0; + ret = uprobe_buffer_enable(); + if (ret) + goto err_flags; + tu->consumer.filter = filter; ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); - if (ret) { - if (file) { - list_del(&link->list); - kfree(link); - tu->tp.flags &= ~TP_FLAG_TRACE; - } else - tu->tp.flags &= ~TP_FLAG_PROFILE; - } + if (ret) + goto err_buffer; + + return 0; + err_buffer: + uprobe_buffer_disable(); + + err_flags: + if (file) { + list_del(&link->list); + kfree(link); + tu->tp.flags &= ~TP_FLAG_TRACE; + } else { + tu->tp.flags &= ~TP_FLAG_PROFILE; + } return ret; } @@ -1009,56 +1023,60 @@ uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event) return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm); } -static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) +static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) { bool done; write_lock(&tu->filter.rwlock); if (event->hw.tp_target) { - /* - * event->parent != NULL means copy_process(), we can avoid - * uprobe_apply(). current->mm must be probed and we can rely - * on dup_mmap() which preserves the already installed bp's. - * - * attr.enable_on_exec means that exec/mmap will install the - * breakpoints we need. - */ + list_del(&event->hw.tp_list); done = tu->filter.nr_systemwide || - event->parent || event->attr.enable_on_exec || + (event->hw.tp_target->flags & PF_EXITING) || uprobe_filter_event(tu, event); - list_add(&event->hw.tp_list, &tu->filter.perf_events); } else { + tu->filter.nr_systemwide--; done = tu->filter.nr_systemwide; - tu->filter.nr_systemwide++; } write_unlock(&tu->filter.rwlock); if (!done) - uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); + return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); return 0; } -static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event) +static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event) { bool done; + int err; write_lock(&tu->filter.rwlock); if (event->hw.tp_target) { - list_del(&event->hw.tp_list); + /* + * event->parent != NULL means copy_process(), we can avoid + * uprobe_apply(). current->mm must be probed and we can rely + * on dup_mmap() which preserves the already installed bp's. + * + * attr.enable_on_exec means that exec/mmap will install the + * breakpoints we need. + */ done = tu->filter.nr_systemwide || - (event->hw.tp_target->flags & PF_EXITING) || + event->parent || event->attr.enable_on_exec || uprobe_filter_event(tu, event); + list_add(&event->hw.tp_list, &tu->filter.perf_events); } else { - tu->filter.nr_systemwide--; done = tu->filter.nr_systemwide; + tu->filter.nr_systemwide++; } write_unlock(&tu->filter.rwlock); - if (!done) - uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); - - return 0; + err = 0; + if (!done) { + err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); + if (err) + uprobe_perf_close(tu, event); + } + return err; } static bool uprobe_perf_filter(struct uprobe_consumer *uc, @@ -1197,12 +1215,6 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) current->utask->vaddr = (unsigned long) &udd; -#ifdef CONFIG_PERF_EVENTS - if ((tu->tp.flags & TP_FLAG_TRACE) == 0 && - !uprobe_perf_filter(&tu->consumer, 0, current->mm)) - return UPROBE_HANDLER_REMOVE; -#endif - if (WARN_ON_ONCE(!uprobe_cpu_buffer)) return 0; diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 33cbd8c203f8..3490407dc7b7 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -492,33 +492,29 @@ static int sys_tracepoint_refcount; void syscall_regfunc(void) { - unsigned long flags; - struct task_struct *g, *t; + struct task_struct *p, *t; if (!sys_tracepoint_refcount) { - read_lock_irqsave(&tasklist_lock, flags); - do_each_thread(g, t) { - /* Skip kernel threads. */ - if (t->mm) - set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT); - } while_each_thread(g, t); - read_unlock_irqrestore(&tasklist_lock, flags); + read_lock(&tasklist_lock); + for_each_process_thread(p, t) { + set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT); + } + read_unlock(&tasklist_lock); } sys_tracepoint_refcount++; } void syscall_unregfunc(void) { - unsigned long flags; - struct task_struct *g, *t; + struct task_struct *p, *t; sys_tracepoint_refcount--; if (!sys_tracepoint_refcount) { - read_lock_irqsave(&tasklist_lock, flags); - do_each_thread(g, t) { + read_lock(&tasklist_lock); + for_each_process_thread(p, t) { clear_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT); - } while_each_thread(g, t); - read_unlock_irqrestore(&tasklist_lock, flags); + } + read_unlock(&tasklist_lock); } } #endif diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 516203e665fc..c3319bd1b040 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -31,6 +31,12 @@ int watchdog_user_enabled = 1; int __read_mostly watchdog_thresh = 10; +#ifdef CONFIG_SMP +int __read_mostly sysctl_softlockup_all_cpu_backtrace; +#else +#define sysctl_softlockup_all_cpu_backtrace 0 +#endif + static int __read_mostly watchdog_running; static u64 __read_mostly sample_period; @@ -47,6 +53,7 @@ static DEFINE_PER_CPU(bool, watchdog_nmi_touch); static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved); static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); #endif +static unsigned long soft_lockup_nmi_warn; /* boot commands */ /* @@ -95,6 +102,15 @@ static int __init nosoftlockup_setup(char *str) } __setup("nosoftlockup", nosoftlockup_setup); /* */ +#ifdef CONFIG_SMP +static int __init softlockup_all_cpu_backtrace_setup(char *str) +{ + sysctl_softlockup_all_cpu_backtrace = + !!simple_strtol(str, NULL, 0); + return 1; +} +__setup("softlockup_all_cpu_backtrace=", softlockup_all_cpu_backtrace_setup); +#endif /* * Hard-lockup warnings should be triggered after just a few seconds. Soft- @@ -271,6 +287,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts); struct pt_regs *regs = get_irq_regs(); int duration; + int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace; /* kick the hardlockup detector */ watchdog_interrupt_count(); @@ -317,6 +334,17 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) if (__this_cpu_read(soft_watchdog_warn) == true) return HRTIMER_RESTART; + if (softlockup_all_cpu_backtrace) { + /* Prevent multiple soft-lockup reports if one cpu is already + * engaged in dumping cpu back traces + */ + if (test_and_set_bit(0, &soft_lockup_nmi_warn)) { + /* Someone else will report us. Let's give up */ + __this_cpu_write(soft_watchdog_warn, true); + return HRTIMER_RESTART; + } + } + printk(KERN_EMERG "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n", smp_processor_id(), duration, current->comm, task_pid_nr(current)); @@ -327,6 +355,17 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) else dump_stack(); + if (softlockup_all_cpu_backtrace) { + /* Avoid generating two back traces for current + * given that one is already made above + */ + trigger_allbutself_cpu_backtrace(); + + clear_bit(0, &soft_lockup_nmi_warn); + /* Barrier to sync with other cpus */ + smp_mb__after_atomic(); + } + if (softlockup_panic) panic("softlockup: hung tasks"); __this_cpu_write(soft_watchdog_warn, true); @@ -527,10 +566,8 @@ static void update_timers_all_cpus(void) int cpu; get_online_cpus(); - preempt_disable(); for_each_online_cpu(cpu) update_timers(cpu); - preempt_enable(); put_online_cpus(); } diff --git a/kernel/workqueue.c b/kernel/workqueue.c index a4bab46cd38e..35974ac69600 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -65,15 +65,12 @@ enum { * be executing on any CPU. The pool behaves as an unbound one. * * Note that DISASSOCIATED should be flipped only while holding - * manager_mutex to avoid changing binding state while - * create_worker() is in progress. + * attach_mutex to avoid changing binding state while + * worker_attach_to_pool() is in progress. */ - POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */ POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */ - POOL_FREEZING = 1 << 3, /* freeze in progress */ /* worker flags */ - WORKER_STARTED = 1 << 0, /* started */ WORKER_DIE = 1 << 1, /* die die die */ WORKER_IDLE = 1 << 2, /* is idle */ WORKER_PREP = 1 << 3, /* preparing to run works */ @@ -124,8 +121,7 @@ enum { * cpu or grabbing pool->lock is enough for read access. If * POOL_DISASSOCIATED is set, it's identical to L. * - * MG: pool->manager_mutex and pool->lock protected. Writes require both - * locks. Reads can happen under either lock. + * A: pool->attach_mutex protected. * * PL: wq_pool_mutex protected. * @@ -163,8 +159,11 @@ struct worker_pool { /* see manage_workers() for details on the two manager mutexes */ struct mutex manager_arb; /* manager arbitration */ - struct mutex manager_mutex; /* manager exclusion */ - struct idr worker_idr; /* MG: worker IDs and iteration */ + struct mutex attach_mutex; /* attach/detach exclusion */ + struct list_head workers; /* A: attached workers */ + struct completion *detach_completion; /* all workers detached */ + + struct ida worker_ida; /* worker IDs for task name */ struct workqueue_attrs *attrs; /* I: worker attributes */ struct hlist_node hash_node; /* PL: unbound_pool_hash node */ @@ -340,16 +339,6 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to, lockdep_is_held(&wq->mutex), \ "sched RCU or wq->mutex should be held") -#ifdef CONFIG_LOCKDEP -#define assert_manager_or_pool_lock(pool) \ - WARN_ONCE(debug_locks && \ - !lockdep_is_held(&(pool)->manager_mutex) && \ - !lockdep_is_held(&(pool)->lock), \ - "pool->manager_mutex or ->lock should be held") -#else -#define assert_manager_or_pool_lock(pool) do { } while (0) -#endif - #define for_each_cpu_worker_pool(pool, cpu) \ for ((pool) = &per_cpu(cpu_worker_pools, cpu)[0]; \ (pool) < &per_cpu(cpu_worker_pools, cpu)[NR_STD_WORKER_POOLS]; \ @@ -375,17 +364,16 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to, /** * for_each_pool_worker - iterate through all workers of a worker_pool * @worker: iteration cursor - * @wi: integer used for iteration * @pool: worker_pool to iterate workers of * - * This must be called with either @pool->manager_mutex or ->lock held. + * This must be called with @pool->attach_mutex. * * The if/else clause exists only for the lockdep assertion and can be * ignored. */ -#define for_each_pool_worker(worker, wi, pool) \ - idr_for_each_entry(&(pool)->worker_idr, (worker), (wi)) \ - if (({ assert_manager_or_pool_lock((pool)); false; })) { } \ +#define for_each_pool_worker(worker, pool) \ + list_for_each_entry((worker), &(pool)->workers, node) \ + if (({ lockdep_assert_held(&pool->attach_mutex); false; })) { } \ else /** @@ -763,13 +751,6 @@ static bool need_to_create_worker(struct worker_pool *pool) return need_more_worker(pool) && !may_start_working(pool); } -/* Do I need to be the manager? */ -static bool need_to_manage_workers(struct worker_pool *pool) -{ - return need_to_create_worker(pool) || - (pool->flags & POOL_MANAGE_WORKERS); -} - /* Do we have too many workers and should some go away? */ static bool too_many_workers(struct worker_pool *pool) { @@ -791,8 +772,8 @@ static bool too_many_workers(struct worker_pool *pool) * Wake up functions. */ -/* Return the first worker. Safe with preemption disabled */ -static struct worker *first_worker(struct worker_pool *pool) +/* Return the first idle worker. Safe with preemption disabled */ +static struct worker *first_idle_worker(struct worker_pool *pool) { if (unlikely(list_empty(&pool->idle_list))) return NULL; @@ -811,7 +792,7 @@ static struct worker *first_worker(struct worker_pool *pool) */ static void wake_up_worker(struct worker_pool *pool) { - struct worker *worker = first_worker(pool); + struct worker *worker = first_idle_worker(pool); if (likely(worker)) wake_up_process(worker->task); @@ -885,7 +866,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu) */ if (atomic_dec_and_test(&pool->nr_running) && !list_empty(&pool->worklist)) - to_wakeup = first_worker(pool); + to_wakeup = first_idle_worker(pool); return to_wakeup ? to_wakeup->task : NULL; } @@ -1621,70 +1602,6 @@ static void worker_leave_idle(struct worker *worker) list_del_init(&worker->entry); } -/** - * worker_maybe_bind_and_lock - try to bind %current to worker_pool and lock it - * @pool: target worker_pool - * - * Bind %current to the cpu of @pool if it is associated and lock @pool. - * - * Works which are scheduled while the cpu is online must at least be - * scheduled to a worker which is bound to the cpu so that if they are - * flushed from cpu callbacks while cpu is going down, they are - * guaranteed to execute on the cpu. - * - * This function is to be used by unbound workers and rescuers to bind - * themselves to the target cpu and may race with cpu going down or - * coming online. kthread_bind() can't be used because it may put the - * worker to already dead cpu and set_cpus_allowed_ptr() can't be used - * verbatim as it's best effort and blocking and pool may be - * [dis]associated in the meantime. - * - * This function tries set_cpus_allowed() and locks pool and verifies the - * binding against %POOL_DISASSOCIATED which is set during - * %CPU_DOWN_PREPARE and cleared during %CPU_ONLINE, so if the worker - * enters idle state or fetches works without dropping lock, it can - * guarantee the scheduling requirement described in the first paragraph. - * - * CONTEXT: - * Might sleep. Called without any lock but returns with pool->lock - * held. - * - * Return: - * %true if the associated pool is online (@worker is successfully - * bound), %false if offline. - */ -static bool worker_maybe_bind_and_lock(struct worker_pool *pool) -__acquires(&pool->lock) -{ - while (true) { - /* - * The following call may fail, succeed or succeed - * without actually migrating the task to the cpu if - * it races with cpu hotunplug operation. Verify - * against POOL_DISASSOCIATED. - */ - if (!(pool->flags & POOL_DISASSOCIATED)) - set_cpus_allowed_ptr(current, pool->attrs->cpumask); - - spin_lock_irq(&pool->lock); - if (pool->flags & POOL_DISASSOCIATED) - return false; - if (task_cpu(current) == pool->cpu && - cpumask_equal(¤t->cpus_allowed, pool->attrs->cpumask)) - return true; - spin_unlock_irq(&pool->lock); - - /* - * We've raced with CPU hot[un]plug. Give it a breather - * and retry migration. cond_resched() is required here; - * otherwise, we might deadlock against cpu_stop trying to - * bring down the CPU on non-preemptive kernel. - */ - cpu_relax(); - cond_resched(); - } -} - static struct worker *alloc_worker(void) { struct worker *worker; @@ -1693,6 +1610,7 @@ static struct worker *alloc_worker(void) if (worker) { INIT_LIST_HEAD(&worker->entry); INIT_LIST_HEAD(&worker->scheduled); + INIT_LIST_HEAD(&worker->node); /* on creation a worker is in !idle && prep state */ worker->flags = WORKER_PREP; } @@ -1700,12 +1618,68 @@ static struct worker *alloc_worker(void) } /** + * worker_attach_to_pool() - attach a worker to a pool + * @worker: worker to be attached + * @pool: the target pool + * + * Attach @worker to @pool. Once attached, the %WORKER_UNBOUND flag and + * cpu-binding of @worker are kept coordinated with the pool across + * cpu-[un]hotplugs. + */ +static void worker_attach_to_pool(struct worker *worker, + struct worker_pool *pool) +{ + mutex_lock(&pool->attach_mutex); + + /* + * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any + * online CPUs. It'll be re-applied when any of the CPUs come up. + */ + set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); + + /* + * The pool->attach_mutex ensures %POOL_DISASSOCIATED remains + * stable across this function. See the comments above the + * flag definition for details. + */ + if (pool->flags & POOL_DISASSOCIATED) + worker->flags |= WORKER_UNBOUND; + + list_add_tail(&worker->node, &pool->workers); + + mutex_unlock(&pool->attach_mutex); +} + +/** + * worker_detach_from_pool() - detach a worker from its pool + * @worker: worker which is attached to its pool + * @pool: the pool @worker is attached to + * + * Undo the attaching which had been done in worker_attach_to_pool(). The + * caller worker shouldn't access to the pool after detached except it has + * other reference to the pool. + */ +static void worker_detach_from_pool(struct worker *worker, + struct worker_pool *pool) +{ + struct completion *detach_completion = NULL; + + mutex_lock(&pool->attach_mutex); + list_del(&worker->node); + if (list_empty(&pool->workers)) + detach_completion = pool->detach_completion; + mutex_unlock(&pool->attach_mutex); + + if (detach_completion) + complete(detach_completion); +} + +/** * create_worker - create a new workqueue worker * @pool: pool the new worker will belong to * - * Create a new worker which is bound to @pool. The returned worker - * can be started by calling start_worker() or destroyed using - * destroy_worker(). + * Create a new worker which is attached to @pool. The new worker must be + * started by start_worker(). * * CONTEXT: * Might sleep. Does GFP_KERNEL allocations. @@ -1719,19 +1693,8 @@ static struct worker *create_worker(struct worker_pool *pool) int id = -1; char id_buf[16]; - lockdep_assert_held(&pool->manager_mutex); - - /* - * ID is needed to determine kthread name. Allocate ID first - * without installing the pointer. - */ - idr_preload(GFP_KERNEL); - spin_lock_irq(&pool->lock); - - id = idr_alloc(&pool->worker_idr, NULL, 0, 0, GFP_NOWAIT); - - spin_unlock_irq(&pool->lock); - idr_preload_end(); + /* ID is needed to determine kthread name */ + id = ida_simple_get(&pool->worker_ida, 0, 0, GFP_KERNEL); if (id < 0) goto fail; @@ -1758,33 +1721,14 @@ static struct worker *create_worker(struct worker_pool *pool) /* prevent userland from meddling with cpumask of workqueue workers */ worker->task->flags |= PF_NO_SETAFFINITY; - /* - * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any - * online CPUs. It'll be re-applied when any of the CPUs come up. - */ - set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); - - /* - * The caller is responsible for ensuring %POOL_DISASSOCIATED - * remains stable across this function. See the comments above the - * flag definition for details. - */ - if (pool->flags & POOL_DISASSOCIATED) - worker->flags |= WORKER_UNBOUND; - - /* successful, commit the pointer to idr */ - spin_lock_irq(&pool->lock); - idr_replace(&pool->worker_idr, worker, worker->id); - spin_unlock_irq(&pool->lock); + /* successful, attach the worker to the pool */ + worker_attach_to_pool(worker, pool); return worker; fail: - if (id >= 0) { - spin_lock_irq(&pool->lock); - idr_remove(&pool->worker_idr, id); - spin_unlock_irq(&pool->lock); - } + if (id >= 0) + ida_simple_remove(&pool->worker_ida, id); kfree(worker); return NULL; } @@ -1800,7 +1744,6 @@ fail: */ static void start_worker(struct worker *worker) { - worker->flags |= WORKER_STARTED; worker->pool->nr_workers++; worker_enter_idle(worker); wake_up_process(worker->task); @@ -1818,8 +1761,6 @@ static int create_and_start_worker(struct worker_pool *pool) { struct worker *worker; - mutex_lock(&pool->manager_mutex); - worker = create_worker(pool); if (worker) { spin_lock_irq(&pool->lock); @@ -1827,8 +1768,6 @@ static int create_and_start_worker(struct worker_pool *pool) spin_unlock_irq(&pool->lock); } - mutex_unlock(&pool->manager_mutex); - return worker ? 0 : -ENOMEM; } @@ -1836,46 +1775,30 @@ static int create_and_start_worker(struct worker_pool *pool) * destroy_worker - destroy a workqueue worker * @worker: worker to be destroyed * - * Destroy @worker and adjust @pool stats accordingly. + * Destroy @worker and adjust @pool stats accordingly. The worker should + * be idle. * * CONTEXT: - * spin_lock_irq(pool->lock) which is released and regrabbed. + * spin_lock_irq(pool->lock). */ static void destroy_worker(struct worker *worker) { struct worker_pool *pool = worker->pool; - lockdep_assert_held(&pool->manager_mutex); lockdep_assert_held(&pool->lock); /* sanity check frenzy */ if (WARN_ON(worker->current_work) || - WARN_ON(!list_empty(&worker->scheduled))) + WARN_ON(!list_empty(&worker->scheduled)) || + WARN_ON(!(worker->flags & WORKER_IDLE))) return; - if (worker->flags & WORKER_STARTED) - pool->nr_workers--; - if (worker->flags & WORKER_IDLE) - pool->nr_idle--; - - /* - * Once WORKER_DIE is set, the kworker may destroy itself at any - * point. Pin to ensure the task stays until we're done with it. - */ - get_task_struct(worker->task); + pool->nr_workers--; + pool->nr_idle--; list_del_init(&worker->entry); worker->flags |= WORKER_DIE; - - idr_remove(&pool->worker_idr, worker->id); - - spin_unlock_irq(&pool->lock); - - kthread_stop(worker->task); - put_task_struct(worker->task); - kfree(worker); - - spin_lock_irq(&pool->lock); + wake_up_process(worker->task); } static void idle_worker_timeout(unsigned long __pool) @@ -1884,7 +1807,7 @@ static void idle_worker_timeout(unsigned long __pool) spin_lock_irq(&pool->lock); - if (too_many_workers(pool)) { + while (too_many_workers(pool)) { struct worker *worker; unsigned long expires; @@ -1892,13 +1815,12 @@ static void idle_worker_timeout(unsigned long __pool) worker = list_entry(pool->idle_list.prev, struct worker, entry); expires = worker->last_active + IDLE_WORKER_TIMEOUT; - if (time_before(jiffies, expires)) + if (time_before(jiffies, expires)) { mod_timer(&pool->idle_timer, expires); - else { - /* it's been idle for too long, wake up manager */ - pool->flags |= POOL_MANAGE_WORKERS; - wake_up_worker(pool); + break; } + + destroy_worker(worker); } spin_unlock_irq(&pool->lock); @@ -2017,44 +1939,6 @@ restart: } /** - * maybe_destroy_worker - destroy workers which have been idle for a while - * @pool: pool to destroy workers for - * - * Destroy @pool workers which have been idle for longer than - * IDLE_WORKER_TIMEOUT. - * - * LOCKING: - * spin_lock_irq(pool->lock) which may be released and regrabbed - * multiple times. Called only from manager. - * - * Return: - * %false if no action was taken and pool->lock stayed locked, %true - * otherwise. - */ -static bool maybe_destroy_workers(struct worker_pool *pool) -{ - bool ret = false; - - while (too_many_workers(pool)) { - struct worker *worker; - unsigned long expires; - - worker = list_entry(pool->idle_list.prev, struct worker, entry); - expires = worker->last_active + IDLE_WORKER_TIMEOUT; - - if (time_before(jiffies, expires)) { - mod_timer(&pool->idle_timer, expires); - break; - } - - destroy_worker(worker); - ret = true; - } - - return ret; -} - -/** * manage_workers - manage worker pool * @worker: self * @@ -2083,8 +1967,6 @@ static bool manage_workers(struct worker *worker) bool ret = false; /* - * Managership is governed by two mutexes - manager_arb and - * manager_mutex. manager_arb handles arbitration of manager role. * Anyone who successfully grabs manager_arb wins the arbitration * and becomes the manager. mutex_trylock() on pool->manager_arb * failure while holding pool->lock reliably indicates that someone @@ -2093,40 +1975,12 @@ static bool manage_workers(struct worker *worker) * grabbing manager_arb is responsible for actually performing * manager duties. If manager_arb is grabbed and released without * actual management, the pool may stall indefinitely. - * - * manager_mutex is used for exclusion of actual management - * operations. The holder of manager_mutex can be sure that none - * of management operations, including creation and destruction of - * workers, won't take place until the mutex is released. Because - * manager_mutex doesn't interfere with manager role arbitration, - * it is guaranteed that the pool's management, while may be - * delayed, won't be disturbed by someone else grabbing - * manager_mutex. */ if (!mutex_trylock(&pool->manager_arb)) return ret; - /* - * With manager arbitration won, manager_mutex would be free in - * most cases. trylock first without dropping @pool->lock. - */ - if (unlikely(!mutex_trylock(&pool->manager_mutex))) { - spin_unlock_irq(&pool->lock); - mutex_lock(&pool->manager_mutex); - spin_lock_irq(&pool->lock); - ret = true; - } - - pool->flags &= ~POOL_MANAGE_WORKERS; - - /* - * Destroy and then create so that may_start_working() is true - * on return. - */ - ret |= maybe_destroy_workers(pool); ret |= maybe_create_worker(pool); - mutex_unlock(&pool->manager_mutex); mutex_unlock(&pool->manager_arb); return ret; } @@ -2314,6 +2168,11 @@ woke_up: spin_unlock_irq(&pool->lock); WARN_ON_ONCE(!list_empty(&worker->entry)); worker->task->flags &= ~PF_WQ_WORKER; + + set_task_comm(worker->task, "kworker/dying"); + ida_simple_remove(&pool->worker_ida, worker->id); + worker_detach_from_pool(worker, pool); + kfree(worker); return 0; } @@ -2361,9 +2220,6 @@ recheck: worker_set_flags(worker, WORKER_PREP, false); sleep: - if (unlikely(need_to_manage_workers(pool)) && manage_workers(worker)) - goto recheck; - /* * pool->lock is held and there's no work to process and no need to * manage, sleep. Workers are woken up only while holding @@ -2440,8 +2296,9 @@ repeat: spin_unlock_irq(&wq_mayday_lock); - /* migrate to the target cpu if possible */ - worker_maybe_bind_and_lock(pool); + worker_attach_to_pool(rescuer, pool); + + spin_lock_irq(&pool->lock); rescuer->pool = pool; /* @@ -2454,6 +2311,11 @@ repeat: move_linked_works(work, scheduled, &n); process_scheduled_works(rescuer); + spin_unlock_irq(&pool->lock); + + worker_detach_from_pool(rescuer, pool); + + spin_lock_irq(&pool->lock); /* * Put the reference grabbed by send_mayday(). @pool won't @@ -3422,6 +3284,7 @@ int workqueue_sysfs_register(struct workqueue_struct *wq) } } + dev_set_uevent_suppress(&wq_dev->dev, false); kobject_uevent(&wq_dev->dev.kobj, KOBJ_ADD); return 0; } @@ -3550,9 +3413,10 @@ static int init_worker_pool(struct worker_pool *pool) (unsigned long)pool); mutex_init(&pool->manager_arb); - mutex_init(&pool->manager_mutex); - idr_init(&pool->worker_idr); + mutex_init(&pool->attach_mutex); + INIT_LIST_HEAD(&pool->workers); + ida_init(&pool->worker_ida); INIT_HLIST_NODE(&pool->hash_node); pool->refcnt = 1; @@ -3567,7 +3431,7 @@ static void rcu_free_pool(struct rcu_head *rcu) { struct worker_pool *pool = container_of(rcu, struct worker_pool, rcu); - idr_destroy(&pool->worker_idr); + ida_destroy(&pool->worker_ida); free_workqueue_attrs(pool->attrs); kfree(pool); } @@ -3585,6 +3449,7 @@ static void rcu_free_pool(struct rcu_head *rcu) */ static void put_unbound_pool(struct worker_pool *pool) { + DECLARE_COMPLETION_ONSTACK(detach_completion); struct worker *worker; lockdep_assert_held(&wq_pool_mutex); @@ -3605,18 +3470,24 @@ static void put_unbound_pool(struct worker_pool *pool) /* * Become the manager and destroy all workers. Grabbing * manager_arb prevents @pool's workers from blocking on - * manager_mutex. + * attach_mutex. */ mutex_lock(&pool->manager_arb); - mutex_lock(&pool->manager_mutex); - spin_lock_irq(&pool->lock); - while ((worker = first_worker(pool))) + spin_lock_irq(&pool->lock); + while ((worker = first_idle_worker(pool))) destroy_worker(worker); WARN_ON(pool->nr_workers || pool->nr_idle); - spin_unlock_irq(&pool->lock); - mutex_unlock(&pool->manager_mutex); + + mutex_lock(&pool->attach_mutex); + if (!list_empty(&pool->workers)) + pool->detach_completion = &detach_completion; + mutex_unlock(&pool->attach_mutex); + + if (pool->detach_completion) + wait_for_completion(pool->detach_completion); + mutex_unlock(&pool->manager_arb); /* shut down the timers */ @@ -3662,9 +3533,6 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs) if (!pool || init_worker_pool(pool) < 0) goto fail; - if (workqueue_freezing) - pool->flags |= POOL_FREEZING; - lockdep_set_subclass(&pool->lock, 1); /* see put_pwq() */ copy_workqueue_attrs(pool->attrs, attrs); @@ -3771,7 +3639,12 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq) spin_lock_irq(&pwq->pool->lock); - if (!freezable || !(pwq->pool->flags & POOL_FREEZING)) { + /* + * During [un]freezing, the caller is responsible for ensuring that + * this function is called at least once after @workqueue_freezing + * is updated and visible. + */ + if (!freezable || !workqueue_freezing) { pwq->max_active = wq->saved_max_active; while (!list_empty(&pwq->delayed_works) && @@ -4103,17 +3976,13 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, * Let's determine what needs to be done. If the target cpumask is * different from wq's, we need to compare it to @pwq's and create * a new one if they don't match. If the target cpumask equals - * wq's, the default pwq should be used. If @pwq is already the - * default one, nothing to do; otherwise, install the default one. + * wq's, the default pwq should be used. */ if (wq_calc_node_cpumask(wq->unbound_attrs, node, cpu_off, cpumask)) { if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask)) goto out_unlock; } else { - if (pwq == wq->dfl_pwq) - goto out_unlock; - else - goto use_dfl_pwq; + goto use_dfl_pwq; } mutex_unlock(&wq->mutex); @@ -4121,8 +3990,8 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, /* create a new pwq */ pwq = alloc_unbound_pwq(wq, target_attrs); if (!pwq) { - pr_warning("workqueue: allocation failed while updating NUMA affinity of \"%s\"\n", - wq->name); + pr_warn("workqueue: allocation failed while updating NUMA affinity of \"%s\"\n", + wq->name); mutex_lock(&wq->mutex); goto use_dfl_pwq; } @@ -4599,28 +4468,27 @@ static void wq_unbind_fn(struct work_struct *work) int cpu = smp_processor_id(); struct worker_pool *pool; struct worker *worker; - int wi; for_each_cpu_worker_pool(pool, cpu) { WARN_ON_ONCE(cpu != smp_processor_id()); - mutex_lock(&pool->manager_mutex); + mutex_lock(&pool->attach_mutex); spin_lock_irq(&pool->lock); /* - * We've blocked all manager operations. Make all workers + * We've blocked all attach/detach operations. Make all workers * unbound and set DISASSOCIATED. Before this, all workers * except for the ones which are still executing works from * before the last CPU down must be on the cpu. After * this, they may become diasporas. */ - for_each_pool_worker(worker, wi, pool) + for_each_pool_worker(worker, pool) worker->flags |= WORKER_UNBOUND; pool->flags |= POOL_DISASSOCIATED; spin_unlock_irq(&pool->lock); - mutex_unlock(&pool->manager_mutex); + mutex_unlock(&pool->attach_mutex); /* * Call schedule() so that we cross rq->lock and thus can @@ -4660,9 +4528,8 @@ static void wq_unbind_fn(struct work_struct *work) static void rebind_workers(struct worker_pool *pool) { struct worker *worker; - int wi; - lockdep_assert_held(&pool->manager_mutex); + lockdep_assert_held(&pool->attach_mutex); /* * Restore CPU affinity of all workers. As all idle workers should @@ -4671,13 +4538,13 @@ static void rebind_workers(struct worker_pool *pool) * of all workers first and then clear UNBOUND. As we're called * from CPU_ONLINE, the following shouldn't fail. */ - for_each_pool_worker(worker, wi, pool) + for_each_pool_worker(worker, pool) WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask) < 0); spin_lock_irq(&pool->lock); - for_each_pool_worker(worker, wi, pool) { + for_each_pool_worker(worker, pool) { unsigned int worker_flags = worker->flags; /* @@ -4729,9 +4596,8 @@ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu) { static cpumask_t cpumask; struct worker *worker; - int wi; - lockdep_assert_held(&pool->manager_mutex); + lockdep_assert_held(&pool->attach_mutex); /* is @cpu allowed for @pool? */ if (!cpumask_test_cpu(cpu, pool->attrs->cpumask)) @@ -4743,7 +4609,7 @@ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu) return; /* as we're called from CPU_ONLINE, the following shouldn't fail */ - for_each_pool_worker(worker, wi, pool) + for_each_pool_worker(worker, pool) WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask) < 0); } @@ -4776,7 +4642,7 @@ static int workqueue_cpu_up_callback(struct notifier_block *nfb, mutex_lock(&wq_pool_mutex); for_each_pool(pool, pi) { - mutex_lock(&pool->manager_mutex); + mutex_lock(&pool->attach_mutex); if (pool->cpu == cpu) { spin_lock_irq(&pool->lock); @@ -4788,7 +4654,7 @@ static int workqueue_cpu_up_callback(struct notifier_block *nfb, restore_unbound_workers_cpumask(pool, cpu); } - mutex_unlock(&pool->manager_mutex); + mutex_unlock(&pool->attach_mutex); } /* update NUMA affinity of unbound workqueues */ @@ -4887,24 +4753,14 @@ EXPORT_SYMBOL_GPL(work_on_cpu); */ void freeze_workqueues_begin(void) { - struct worker_pool *pool; struct workqueue_struct *wq; struct pool_workqueue *pwq; - int pi; mutex_lock(&wq_pool_mutex); WARN_ON_ONCE(workqueue_freezing); workqueue_freezing = true; - /* set FREEZING */ - for_each_pool(pool, pi) { - spin_lock_irq(&pool->lock); - WARN_ON_ONCE(pool->flags & POOL_FREEZING); - pool->flags |= POOL_FREEZING; - spin_unlock_irq(&pool->lock); - } - list_for_each_entry(wq, &workqueues, list) { mutex_lock(&wq->mutex); for_each_pwq(pwq, wq) @@ -4974,21 +4830,13 @@ void thaw_workqueues(void) { struct workqueue_struct *wq; struct pool_workqueue *pwq; - struct worker_pool *pool; - int pi; mutex_lock(&wq_pool_mutex); if (!workqueue_freezing) goto out_unlock; - /* clear FREEZING */ - for_each_pool(pool, pi) { - spin_lock_irq(&pool->lock); - WARN_ON_ONCE(!(pool->flags & POOL_FREEZING)); - pool->flags &= ~POOL_FREEZING; - spin_unlock_irq(&pool->lock); - } + workqueue_freezing = false; /* restore max_active and repopulate worklist */ list_for_each_entry(wq, &workqueues, list) { @@ -4998,7 +4846,6 @@ void thaw_workqueues(void) mutex_unlock(&wq->mutex); } - workqueue_freezing = false; out_unlock: mutex_unlock(&wq_pool_mutex); } @@ -5033,7 +4880,7 @@ static void __init wq_numa_init(void) BUG_ON(!tbl); for_each_node(node) - BUG_ON(!alloc_cpumask_var_node(&tbl[node], GFP_KERNEL, + BUG_ON(!zalloc_cpumask_var_node(&tbl[node], GFP_KERNEL, node_online(node) ? node : NUMA_NO_NODE)); for_each_possible_cpu(cpu) { diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index 7e2204db0b1a..45215870ac6c 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -37,6 +37,8 @@ struct worker { struct task_struct *task; /* I: worker task */ struct worker_pool *pool; /* I: the associated pool */ /* L: for rescuers */ + struct list_head node; /* A: anchored at pool->workers */ + /* A: runs through worker->node */ unsigned long last_active; /* L: last active timestamp */ unsigned int flags; /* X: flags */ |