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| author |   Jiri Kosina <jkosina@suse.cz> | 2020-10-15 20:37:01 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2020-10-15 20:37:01 +0200 |
| commit | 62b31a045757eac81fed94b19df47418a0818528 (patch) | |
| tree | 285fda56df8304dff6ba929bad65ddfb4e4fd726 /kernel/task_work.c | |
| parent | Merge branch 'for-5.10/apple' into for-linus (diff) | |
| parent | HID: hid-debug: fix nonblocking read semantics wrt EIO/ERESTARTSYS (diff) | |
| download | wireguard-linux-62b31a045757eac81fed94b19df47418a0818528.tar.xz wireguard-linux-62b31a045757eac81fed94b19df47418a0818528.zip | |
Merge branch 'for-5.10/core' into for-linus
- nonblocking read semantics fix for hid-debug
Diffstat (limited to 'kernel/task_work.c')
| -rw-r--r-- | kernel/task_work.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/task_work.c b/kernel/task_work.c index 5c0848ca1287..613b2d634af8 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -42,7 +42,13 @@ task_work_add(struct task_struct *task, struct callback_head *work, int notify) set_notify_resume(task); break; case TWA_SIGNAL: - if (lock_task_sighand(task, &flags)) { + /* + * Only grab the sighand lock if we don't already have some + * task_work pending. This pairs with the smp_store_mb() + * in get_signal(), see comment there. + */ + if (!(READ_ONCE(task->jobctl) & JOBCTL_TASK_WORK) && + lock_task_sighand(task, &flags)) { task->jobctl |= JOBCTL_TASK_WORK; signal_wake_up(task, 0); unlock_task_sighand(task, &flags); |