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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-25 10:51:53 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-25 10:51:53 +0100
commitff85f707ac49ad77b7cf8dcef38e7fcd468ca3d6 (patch)
tree886db57888058d507c6a14000cf4dd2b581311e1 /kernel
parente9533ae539d5cc3d5fc501529d2df7b77e20449c (diff)
parentbc465aa9d045feb0e13b4a8f32cc33c1943f62d6 (diff)
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Merge 4.0-rc5 into char-misc-next
We want those fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpuset.c9
-rw-r--r--kernel/events/core.c2
-rw-r--r--kernel/livepatch/core.c30
-rw-r--r--kernel/module.c2
-rw-r--r--kernel/trace/ftrace.c40
-rw-r--r--kernel/workqueue.c56
6 files changed, 113 insertions, 26 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1d1fe9361d29..fc7f4748d34a 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -548,9 +548,6 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr,
rcu_read_lock();
cpuset_for_each_descendant_pre(cp, pos_css, root_cs) {
- if (cp == root_cs)
- continue;
-
/* skip the whole subtree if @cp doesn't have any CPU */
if (cpumask_empty(cp->cpus_allowed)) {
pos_css = css_rightmost_descendant(pos_css);
@@ -873,7 +870,7 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
* If it becomes empty, inherit the effective mask of the
* parent, which is guaranteed to have some CPUs.
*/
- if (cpumask_empty(new_cpus))
+ if (cgroup_on_dfl(cp->css.cgroup) && cpumask_empty(new_cpus))
cpumask_copy(new_cpus, parent->effective_cpus);
/* Skip the whole subtree if the cpumask remains the same. */
@@ -1129,7 +1126,7 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
* If it becomes empty, inherit the effective mask of the
* parent, which is guaranteed to have some MEMs.
*/
- if (nodes_empty(*new_mems))
+ if (cgroup_on_dfl(cp->css.cgroup) && nodes_empty(*new_mems))
*new_mems = parent->effective_mems;
/* Skip the whole subtree if the nodemask remains the same. */
@@ -1979,7 +1976,9 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
spin_lock_irq(&callback_lock);
cs->mems_allowed = parent->mems_allowed;
+ cs->effective_mems = parent->mems_allowed;
cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
+ cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
spin_unlock_irq(&callback_lock);
out_unlock:
mutex_unlock(&cpuset_mutex);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f04daabfd1cf..453ef61311d4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3591,7 +3591,7 @@ static void put_event(struct perf_event *event)
ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING);
WARN_ON_ONCE(ctx->parent_ctx);
perf_remove_from_context(event, true);
- mutex_unlock(&ctx->mutex);
+ perf_event_ctx_unlock(event, ctx);
_free_event(event);
}
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 01ca08804f51..3f9f1d6b4c2e 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -89,16 +89,28 @@ static bool klp_is_object_loaded(struct klp_object *obj)
/* sets obj->mod if object is not vmlinux and module is found */
static void klp_find_object_module(struct klp_object *obj)
{
+ struct module *mod;
+
if (!klp_is_module(obj))
return;
mutex_lock(&module_mutex);
/*
- * We don't need to take a reference on the module here because we have
- * the klp_mutex, which is also taken by the module notifier. This
- * prevents any module from unloading until we release the klp_mutex.
+ * We do not want to block removal of patched modules and therefore
+ * we do not take a reference here. The patches are removed by
+ * a going module handler instead.
+ */
+ mod = find_module(obj->name);
+ /*
+ * Do not mess work of the module coming and going notifiers.
+ * Note that the patch might still be needed before the going handler
+ * is called. Module functions can be called even in the GOING state
+ * until mod->exit() finishes. This is especially important for
+ * patches that modify semantic of the functions.
*/
- obj->mod = find_module(obj->name);
+ if (mod && mod->klp_alive)
+ obj->mod = mod;
+
mutex_unlock(&module_mutex);
}
@@ -767,6 +779,7 @@ static int klp_init_object(struct klp_patch *patch, struct klp_object *obj)
return -EINVAL;
obj->state = KLP_DISABLED;
+ obj->mod = NULL;
klp_find_object_module(obj);
@@ -961,6 +974,15 @@ static int klp_module_notify(struct notifier_block *nb, unsigned long action,
mutex_lock(&klp_mutex);
+ /*
+ * Each module has to know that the notifier has been called.
+ * We never know what module will get patched by a new patch.
+ */
+ if (action == MODULE_STATE_COMING)
+ mod->klp_alive = true;
+ else /* MODULE_STATE_GOING */
+ mod->klp_alive = false;
+
list_for_each_entry(patch, &klp_patches, list) {
for (obj = patch->objs; obj->funcs; obj++) {
if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
diff --git a/kernel/module.c b/kernel/module.c
index cc93cf68653c..b3d634ed06c9 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -56,7 +56,6 @@
#include <linux/async.h>
#include <linux/percpu.h>
#include <linux/kmemleak.h>
-#include <linux/kasan.h>
#include <linux/jump_label.h>
#include <linux/pfn.h>
#include <linux/bsearch.h>
@@ -1814,7 +1813,6 @@ static void unset_module_init_ro_nx(struct module *mod) { }
void __weak module_memfree(void *module_region)
{
vfree(module_region);
- kasan_module_free(module_region);
}
void __weak module_arch_cleanup(struct module *mod)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 45e5cb143d17..4f228024055b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1059,6 +1059,12 @@ static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
static struct pid * const ftrace_swapper_pid = &init_struct_pid;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int ftrace_graph_active;
+#else
+# define ftrace_graph_active 0
+#endif
+
#ifdef CONFIG_DYNAMIC_FTRACE
static struct ftrace_ops *removed_ops;
@@ -2041,8 +2047,12 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
if (!ftrace_rec_count(rec))
rec->flags = 0;
else
- /* Just disable the record (keep REGS state) */
- rec->flags &= ~FTRACE_FL_ENABLED;
+ /*
+ * Just disable the record, but keep the ops TRAMP
+ * and REGS states. The _EN flags must be disabled though.
+ */
+ rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
+ FTRACE_FL_REGS_EN);
}
return FTRACE_UPDATE_MAKE_NOP;
@@ -2688,24 +2698,36 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
static void ftrace_startup_sysctl(void)
{
+ int command;
+
if (unlikely(ftrace_disabled))
return;
/* Force update next time */
saved_ftrace_func = NULL;
/* ftrace_start_up is true if we want ftrace running */
- if (ftrace_start_up)
- ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+ if (ftrace_start_up) {
+ command = FTRACE_UPDATE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_START_FUNC_RET;
+ ftrace_startup_enable(command);
+ }
}
static void ftrace_shutdown_sysctl(void)
{
+ int command;
+
if (unlikely(ftrace_disabled))
return;
/* ftrace_start_up is true if ftrace is running */
- if (ftrace_start_up)
- ftrace_run_update_code(FTRACE_DISABLE_CALLS);
+ if (ftrace_start_up) {
+ command = FTRACE_DISABLE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_STOP_FUNC_RET;
+ ftrace_run_update_code(command);
+ }
}
static cycle_t ftrace_update_time;
@@ -5558,12 +5580,12 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
if (ftrace_enabled) {
- ftrace_startup_sysctl();
-
/* we are starting ftrace again */
if (ftrace_ops_list != &ftrace_list_end)
update_ftrace_function();
+ ftrace_startup_sysctl();
+
} else {
/* stopping ftrace calls (just send to ftrace_stub) */
ftrace_trace_function = ftrace_stub;
@@ -5590,8 +5612,6 @@ static struct ftrace_ops graph_ops = {
ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
};
-static int ftrace_graph_active;
-
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
{
return 0;
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f28849394791..41ff75b478c6 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2728,19 +2728,57 @@ bool flush_work(struct work_struct *work)
}
EXPORT_SYMBOL_GPL(flush_work);
+struct cwt_wait {
+ wait_queue_t wait;
+ struct work_struct *work;
+};
+
+static int cwt_wakefn(wait_queue_t *wait, unsigned mode, int sync, void *key)
+{
+ struct cwt_wait *cwait = container_of(wait, struct cwt_wait, wait);
+
+ if (cwait->work != key)
+ return 0;
+ return autoremove_wake_function(wait, mode, sync, key);
+}
+
static bool __cancel_work_timer(struct work_struct *work, bool is_dwork)
{
+ static DECLARE_WAIT_QUEUE_HEAD(cancel_waitq);
unsigned long flags;
int ret;
do {
ret = try_to_grab_pending(work, is_dwork, &flags);
/*
- * If someone else is canceling, wait for the same event it
- * would be waiting for before retrying.
+ * If someone else is already canceling, wait for it to
+ * finish. flush_work() doesn't work for PREEMPT_NONE
+ * because we may get scheduled between @work's completion
+ * and the other canceling task resuming and clearing
+ * CANCELING - flush_work() will return false immediately
+ * as @work is no longer busy, try_to_grab_pending() will
+ * return -ENOENT as @work is still being canceled and the
+ * other canceling task won't be able to clear CANCELING as
+ * we're hogging the CPU.
+ *
+ * Let's wait for completion using a waitqueue. As this
+ * may lead to the thundering herd problem, use a custom
+ * wake function which matches @work along with exclusive
+ * wait and wakeup.
*/
- if (unlikely(ret == -ENOENT))
- flush_work(work);
+ if (unlikely(ret == -ENOENT)) {
+ struct cwt_wait cwait;
+
+ init_wait(&cwait.wait);
+ cwait.wait.func = cwt_wakefn;
+ cwait.work = work;
+
+ prepare_to_wait_exclusive(&cancel_waitq, &cwait.wait,
+ TASK_UNINTERRUPTIBLE);
+ if (work_is_canceling(work))
+ schedule();
+ finish_wait(&cancel_waitq, &cwait.wait);
+ }
} while (unlikely(ret < 0));
/* tell other tasks trying to grab @work to back off */
@@ -2749,6 +2787,16 @@ static bool __cancel_work_timer(struct work_struct *work, bool is_dwork)
flush_work(work);
clear_work_data(work);
+
+ /*
+ * Paired with prepare_to_wait() above so that either
+ * waitqueue_active() is visible here or !work_is_canceling() is
+ * visible there.
+ */
+ smp_mb();
+ if (waitqueue_active(&cancel_waitq))
+ __wake_up(&cancel_waitq, TASK_NORMAL, 1, work);
+
return ret;
}