diff options
| author | Roland Xu <mu001999@outlook.com> | 2024-08-15 10:58:13 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-09-12 11:06:51 +0200 |
| commit | 1401da1486dc1cdbef6025fd74a3977df3a3e5d0 (patch) | |
| tree | 20db3626193c6b4c45d6b400f4eaaa0e2e95291b | |
| parent | c6bd80f5852227ef7904e4d87d85281c71a7e650 (diff) | |
rtmutex: Drop rt_mutex::wait_lock before scheduling
commit d33d26036a0274b472299d7dcdaa5fb34329f91b upstream.
rt_mutex_handle_deadlock() is called with rt_mutex::wait_lock held. In the
good case it returns with the lock held and in the deadlock case it emits a
warning and goes into an endless scheduling loop with the lock held, which
triggers the 'scheduling in atomic' warning.
Unlock rt_mutex::wait_lock in the dead lock case before issuing the warning
and dropping into the schedule for ever loop.
[ tglx: Moved unlock before the WARN(), removed the pointless comment,
massaged changelog, added Fixes tag ]
Fixes: 3d5c9340d194 ("rtmutex: Handle deadlock detection smarter")
Signed-off-by: Roland Xu <mu001999@outlook.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/ME0P300MB063599BEF0743B8FA339C2CECC802@ME0P300MB0635.AUSP300.PROD.OUTLOOK.COM
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/locking/rtmutex.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index f00dd928fc71..c6a2dafd4a3b 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1202,6 +1202,7 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state, } static void rt_mutex_handle_deadlock(int res, int detect_deadlock, + struct rt_mutex *lock, struct rt_mutex_waiter *w) { /* @@ -1211,6 +1212,7 @@ static void rt_mutex_handle_deadlock(int res, int detect_deadlock, if (res != -EDEADLOCK || detect_deadlock) return; + raw_spin_unlock_irq(&lock->wait_lock); /* * Yell lowdly and stop the task right here. */ @@ -1266,7 +1268,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state, if (unlikely(ret)) { __set_current_state(TASK_RUNNING); remove_waiter(lock, &waiter); - rt_mutex_handle_deadlock(ret, chwalk, &waiter); + rt_mutex_handle_deadlock(ret, chwalk, lock, &waiter); } /* |