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authorThomas Zimmermann <tzimmermann@suse.de>2020-04-17 08:12:22 +0200
committerThomas Zimmermann <tzimmermann@suse.de>2020-04-17 08:12:22 +0200
commit08d99b2c23dfa84ca5b5e5c194062a0550888b71 (patch)
treef4cf81ba52b375bbafd3b7ee2603b3a4cae7fe30 /kernel/task_work.c
parentdrm: Don't free a struct never allocated by drm_gem_fb_init() (diff)
parentLinux 5.7-rc1 (diff)
Merge drm/drm-next into drm-misc-next
Backmerging required to pull topic/phy-compliance. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Diffstat (limited to 'kernel/task_work.c')
-rw-r--r--kernel/task_work.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/kernel/task_work.c b/kernel/task_work.c
index 0fef395662a6..825f28259a19 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -97,16 +97,26 @@ void task_work_run(void)
* work->func() can do task_work_add(), do not set
* work_exited unless the list is empty.
*/
- raw_spin_lock_irq(&task->pi_lock);
do {
+ head = NULL;
work = READ_ONCE(task->task_works);
- head = !work && (task->flags & PF_EXITING) ?
- &work_exited : NULL;
+ if (!work) {
+ if (task->flags & PF_EXITING)
+ head = &work_exited;
+ else
+ break;
+ }
} while (cmpxchg(&task->task_works, work, head) != work);
- raw_spin_unlock_irq(&task->pi_lock);
if (!work)
break;
+ /*
+ * Synchronize with task_work_cancel(). It can not remove
+ * the first entry == work, cmpxchg(task_works) must fail.
+ * But it can remove another entry from the ->next list.
+ */
+ raw_spin_lock_irq(&task->pi_lock);
+ raw_spin_unlock_irq(&task->pi_lock);
do {
next = work->next;