diff options
| author | Roland Xu <mu001999@outlook.com> | 2024-08-15 05:58:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-09-12 12:03:57 +0300 |
| commit | 6a976e9a47e8e5b326de671811561cab12e6fb1f (patch) | |
| tree | 43e9727d6b2177676001edd606f26c365254a34c | |
| parent | 2120e079665b2f747e741f1f270e5b0c9c8e3197 (diff) | |
| download | linux-6a976e9a47e8e5b326de671811561cab12e6fb1f.tar.xz | |
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 734698aec5f9..7c727c4944e6 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1204,6 +1204,7 @@ __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) { /* @@ -1213,6 +1214,7 @@ 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. */ @@ -1268,7 +1270,7 @@ 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); } /* |