diff options
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cgroup.c | 32 | ||||
-rw-r--r-- | kernel/cpu.c | 38 | ||||
-rw-r--r-- | kernel/profile.c | 20 | ||||
-rw-r--r-- | kernel/sched/core.c | 46 | ||||
-rw-r--r-- | kernel/trace/ring_buffer.c | 19 |
5 files changed, 91 insertions, 64 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index fede3d3f28ff..9fcdaa705b6c 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1487,6 +1487,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, struct cgroup_sb_opts opts; struct dentry *dentry; int ret; + bool new_sb; /* * The first time anyone tries to mount a cgroup, enable the list @@ -1603,8 +1604,8 @@ out_unlock: if (ret) return ERR_PTR(ret); - dentry = kernfs_mount(fs_type, flags, root->kf_root, NULL); - if (IS_ERR(dentry)) + dentry = kernfs_mount(fs_type, flags, root->kf_root, &new_sb); + if (IS_ERR(dentry) || !new_sb) cgroup_put(&root->cgrp); return dentry; } @@ -2345,11 +2346,26 @@ static int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent, return ret; } +/* set uid and gid of cgroup dirs and files to that of the creator */ +static int cgroup_kn_set_ugid(struct kernfs_node *kn) +{ + struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID, + .ia_uid = current_fsuid(), + .ia_gid = current_fsgid(), }; + + if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) && + gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID)) + return 0; + + return kernfs_setattr(kn, &iattr); +} + static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft) { char name[CGROUP_FILE_NAME_MAX]; struct kernfs_node *kn; struct lock_class_key *key = NULL; + int ret; #ifdef CONFIG_DEBUG_LOCK_ALLOC key = &cft->lockdep_key; @@ -2357,7 +2373,13 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft) kn = __kernfs_create_file(cgrp->kn, cgroup_file_name(cgrp, cft, name), cgroup_file_mode(cft), 0, cft->kf_ops, cft, NULL, false, key); - return PTR_ERR_OR_ZERO(kn); + if (IS_ERR(kn)) + return PTR_ERR(kn); + + ret = cgroup_kn_set_ugid(kn); + if (ret) + kernfs_remove(kn); + return ret; } /** @@ -3752,6 +3774,10 @@ static long cgroup_create(struct cgroup *parent, const char *name, */ idr_replace(&root->cgroup_idr, cgrp, cgrp->id); + err = cgroup_kn_set_ugid(kn); + if (err) + goto err_destroy; + err = cgroup_addrm_files(cgrp, cgroup_base_files, true); if (err) goto err_destroy; diff --git a/kernel/cpu.c b/kernel/cpu.c index deff2e693766..a9e710eef0e2 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -19,6 +19,7 @@ #include <linux/mutex.h> #include <linux/gfp.h> #include <linux/suspend.h> +#include <linux/lockdep.h> #include "smpboot.h" @@ -27,18 +28,23 @@ static DEFINE_MUTEX(cpu_add_remove_lock); /* - * The following two API's must be used when attempting - * to serialize the updates to cpu_online_mask, cpu_present_mask. + * The following two APIs (cpu_maps_update_begin/done) must be used when + * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. + * The APIs cpu_notifier_register_begin/done() must be used to protect CPU + * hotplug callback (un)registration performed using __register_cpu_notifier() + * or __unregister_cpu_notifier(). */ void cpu_maps_update_begin(void) { mutex_lock(&cpu_add_remove_lock); } +EXPORT_SYMBOL(cpu_notifier_register_begin); void cpu_maps_update_done(void) { mutex_unlock(&cpu_add_remove_lock); } +EXPORT_SYMBOL(cpu_notifier_register_done); static RAW_NOTIFIER_HEAD(cpu_chain); @@ -57,17 +63,30 @@ static struct { * an ongoing cpu hotplug operation. */ int refcount; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif } cpu_hotplug = { .active_writer = NULL, .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), .refcount = 0, +#ifdef CONFIG_DEBUG_LOCK_ALLOC + .dep_map = {.name = "cpu_hotplug.lock" }, +#endif }; +/* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ +#define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map) +#define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) +#define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) + void get_online_cpus(void) { might_sleep(); if (cpu_hotplug.active_writer == current) return; + cpuhp_lock_acquire_read(); mutex_lock(&cpu_hotplug.lock); cpu_hotplug.refcount++; mutex_unlock(&cpu_hotplug.lock); @@ -87,6 +106,7 @@ void put_online_cpus(void) if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) wake_up_process(cpu_hotplug.active_writer); mutex_unlock(&cpu_hotplug.lock); + cpuhp_lock_release(); } EXPORT_SYMBOL_GPL(put_online_cpus); @@ -117,6 +137,7 @@ void cpu_hotplug_begin(void) { cpu_hotplug.active_writer = current; + cpuhp_lock_acquire(); for (;;) { mutex_lock(&cpu_hotplug.lock); if (likely(!cpu_hotplug.refcount)) @@ -131,6 +152,7 @@ void cpu_hotplug_done(void) { cpu_hotplug.active_writer = NULL; mutex_unlock(&cpu_hotplug.lock); + cpuhp_lock_release(); } /* @@ -166,6 +188,11 @@ int __ref register_cpu_notifier(struct notifier_block *nb) return ret; } +int __ref __register_cpu_notifier(struct notifier_block *nb) +{ + return raw_notifier_chain_register(&cpu_chain, nb); +} + static int __cpu_notify(unsigned long val, void *v, int nr_to_call, int *nr_calls) { @@ -189,6 +216,7 @@ static void cpu_notify_nofail(unsigned long val, void *v) BUG_ON(cpu_notify(val, v)); } EXPORT_SYMBOL(register_cpu_notifier); +EXPORT_SYMBOL(__register_cpu_notifier); void __ref unregister_cpu_notifier(struct notifier_block *nb) { @@ -198,6 +226,12 @@ void __ref unregister_cpu_notifier(struct notifier_block *nb) } EXPORT_SYMBOL(unregister_cpu_notifier); +void __ref __unregister_cpu_notifier(struct notifier_block *nb) +{ + raw_notifier_chain_unregister(&cpu_chain, nb); +} +EXPORT_SYMBOL(__unregister_cpu_notifier); + /** * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU * @cpu: a CPU id diff --git a/kernel/profile.c b/kernel/profile.c index 1b266dbe755a..cb980f0c731b 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -591,18 +591,28 @@ out_cleanup: int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */ { struct proc_dir_entry *entry; + int err = 0; if (!prof_on) return 0; - if (create_hash_tables()) - return -ENOMEM; + + cpu_notifier_register_begin(); + + if (create_hash_tables()) { + err = -ENOMEM; + goto out; + } + entry = proc_create("profile", S_IWUSR | S_IRUGO, NULL, &proc_profile_operations); if (!entry) - return 0; + goto out; proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); - hotcpu_notifier(profile_cpu_callback, 0); - return 0; + __hotcpu_notifier(profile_cpu_callback, 0); + +out: + cpu_notifier_register_done(); + return err; } subsys_initcall(create_proc_profile); #endif /* CONFIG_PROC_FS */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 80bd491b718c..268a45ea238c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2846,52 +2846,6 @@ int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, } EXPORT_SYMBOL(default_wake_function); -static long __sched -sleep_on_common(wait_queue_head_t *q, int state, long timeout) -{ - unsigned long flags; - wait_queue_t wait; - - init_waitqueue_entry(&wait, current); - - __set_current_state(state); - - spin_lock_irqsave(&q->lock, flags); - __add_wait_queue(q, &wait); - spin_unlock(&q->lock); - timeout = schedule_timeout(timeout); - spin_lock_irq(&q->lock); - __remove_wait_queue(q, &wait); - spin_unlock_irqrestore(&q->lock, flags); - - return timeout; -} - -void __sched interruptible_sleep_on(wait_queue_head_t *q) -{ - sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); -} -EXPORT_SYMBOL(interruptible_sleep_on); - -long __sched -interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) -{ - return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); -} -EXPORT_SYMBOL(interruptible_sleep_on_timeout); - -void __sched sleep_on(wait_queue_head_t *q) -{ - sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); -} -EXPORT_SYMBOL(sleep_on); - -long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) -{ - return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); -} -EXPORT_SYMBOL(sleep_on_timeout); - #ifdef CONFIG_RT_MUTEXES /* diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index fc4da2d97f9b..c634868c2921 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1301,7 +1301,7 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, * In that off case, we need to allocate for all possible cpus. */ #ifdef CONFIG_HOTPLUG_CPU - get_online_cpus(); + cpu_notifier_register_begin(); cpumask_copy(buffer->cpumask, cpu_online_mask); #else cpumask_copy(buffer->cpumask, cpu_possible_mask); @@ -1324,10 +1324,10 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, #ifdef CONFIG_HOTPLUG_CPU buffer->cpu_notify.notifier_call = rb_cpu_notify; buffer->cpu_notify.priority = 0; - register_cpu_notifier(&buffer->cpu_notify); + __register_cpu_notifier(&buffer->cpu_notify); + cpu_notifier_register_done(); #endif - put_online_cpus(); mutex_init(&buffer->mutex); return buffer; @@ -1341,7 +1341,9 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, fail_free_cpumask: free_cpumask_var(buffer->cpumask); - put_online_cpus(); +#ifdef CONFIG_HOTPLUG_CPU + cpu_notifier_register_done(); +#endif fail_free_buffer: kfree(buffer); @@ -1358,16 +1360,17 @@ ring_buffer_free(struct ring_buffer *buffer) { int cpu; - get_online_cpus(); - #ifdef CONFIG_HOTPLUG_CPU - unregister_cpu_notifier(&buffer->cpu_notify); + cpu_notifier_register_begin(); + __unregister_cpu_notifier(&buffer->cpu_notify); #endif for_each_buffer_cpu(buffer, cpu) rb_free_cpu_buffer(buffer->buffers[cpu]); - put_online_cpus(); +#ifdef CONFIG_HOTPLUG_CPU + cpu_notifier_register_done(); +#endif kfree(buffer->buffers); free_cpumask_var(buffer->cpumask); |