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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2019-07-03 11:21:26 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-07-25 15:39:27 +0200 |
| commit | 6c11c6e3d5e9e5caf8686cd6a5e4552cfc3ea326 (patch) | |
| tree | 3c46421fccf883ceb83abb0b2f42a1a0c662a26b /kernel | |
| parent | 30a35f79faadfeb1b89a7fdb3875f14063519041 (diff) | |
| download | linux-6c11c6e3d5e9e5caf8686cd6a5e4552cfc3ea326.tar.bz2 | |
locking/mutex: Test for initialized mutex
An uninitialized/ zeroed mutex will go unnoticed because there is no
check for it. There is a magic check in the unlock's slowpath path which
might go unnoticed if the unlock happens in the fastpath.
Add a ->magic check early in the mutex_lock() and mutex_trylock() path.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190703092125.lsdf4gpsh2plhavb@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/locking/mutex.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index edd1c082dbf5..5e069734363c 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -908,6 +908,10 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, might_sleep(); +#ifdef CONFIG_DEBUG_MUTEXES + DEBUG_LOCKS_WARN_ON(lock->magic != lock); +#endif + ww = container_of(lock, struct ww_mutex, base); if (use_ww_ctx && ww_ctx) { if (unlikely(ww_ctx == READ_ONCE(ww->ctx))) @@ -1379,8 +1383,13 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock, */ int __sched mutex_trylock(struct mutex *lock) { - bool locked = __mutex_trylock(lock); + bool locked; + +#ifdef CONFIG_DEBUG_MUTEXES + DEBUG_LOCKS_WARN_ON(lock->magic != lock); +#endif + locked = __mutex_trylock(lock); if (locked) mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); |