diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-09-01 14:26:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-09-01 14:26:33 -0700 |
| commit | 51859c5aa6daa96340a81a1ea2de1b48ccadccf1 (patch) | |
| tree | 5162564806eb1bfc7bf2807cdcde7eeefc98e0fe /kernel | |
| parent | 9a754292e88f81acaf26cc5e0cec56b3276029de (diff) | |
| parent | d33d26036a0274b472299d7dcdaa5fb34329f91b (diff) | |
| download | lwn-51859c5aa6daa96340a81a1ea2de1b48ccadccf1.tar.gz lwn-51859c5aa6daa96340a81a1ea2de1b48ccadccf1.zip | |
Merge tag 'locking-urgent-2024-08-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Thomas Gleixner:
"A single fix for rt_mutex.
The deadlock detection code drops into an infinite scheduling loop
while still holding rt_mutex::wait_lock, which rightfully triggers a
'scheduling in atomic' warning.
Unlock it before that"
* tag 'locking-urgent-2024-08-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rtmutex: Drop rt_mutex::wait_lock before scheduling
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/locking/rtmutex.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 88d08eeb8bc0..fba1229f1de6 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1644,6 +1644,7 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock, } static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock, + struct rt_mutex_base *lock, struct rt_mutex_waiter *w) { /* @@ -1656,10 +1657,10 @@ static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock, if (build_ww_mutex() && w->ww_ctx) return; - /* - * Yell loudly and stop the task right here. - */ + raw_spin_unlock_irq(&lock->wait_lock); + WARN(1, "rtmutex deadlock detected\n"); + while (1) { set_current_state(TASK_INTERRUPTIBLE); rt_mutex_schedule(); @@ -1713,7 +1714,7 @@ static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock, } else { __set_current_state(TASK_RUNNING); remove_waiter(lock, waiter); - rt_mutex_handle_deadlock(ret, chwalk, waiter); + rt_mutex_handle_deadlock(ret, chwalk, lock, waiter); } /* |