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| author | Waiman Long | 2018-03-30 23:27:58 +0200 |
|---|---|---|
| committer | Ingo Molnar | 2018-03-31 07:30:50 +0200 |
| commit | 5149cbac4235e12a34cf089592a8bd1c9fcfa467 (patch) | |
| tree | dc8965899aaab98faf1c1f0b7319fd1af2dde616 /kernel/locking/rwsem.c | |
| parent | Merge branch 'linus' into locking/core, to pick up fixes (diff) | |
| download | kernel-qcow2-linux-5149cbac4235e12a34cf089592a8bd1c9fcfa467.tar.gz kernel-qcow2-linux-5149cbac4235e12a34cf089592a8bd1c9fcfa467.tar.xz kernel-qcow2-linux-5149cbac4235e12a34cf089592a8bd1c9fcfa467.zip | |
locking/rwsem: Add DEBUG_RWSEMS to look for lock/unlock mismatches
For a rwsem, locking can either be exclusive or shared. The corresponding
exclusive or shared unlock must be used. Otherwise, the protected data
structures may get corrupted or the lock may be in an inconsistent state.
In order to detect such anomaly, a new configuration option DEBUG_RWSEMS
is added which can be enabled to look for such mismatches and print
warnings that that happens.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1522445280-7767-2-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking/rwsem.c')
| -rw-r--r-- | kernel/locking/rwsem.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index f549c552dbf1..30465a2f2b6c 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -117,6 +117,7 @@ EXPORT_SYMBOL(down_write_trylock); void up_read(struct rw_semaphore *sem) { rwsem_release(&sem->dep_map, 1, _RET_IP_); + DEBUG_RWSEMS_WARN_ON(sem->owner != RWSEM_READER_OWNED); __up_read(sem); } @@ -129,6 +130,7 @@ EXPORT_SYMBOL(up_read); void up_write(struct rw_semaphore *sem) { rwsem_release(&sem->dep_map, 1, _RET_IP_); + DEBUG_RWSEMS_WARN_ON(sem->owner != current); rwsem_clear_owner(sem); __up_write(sem); @@ -142,6 +144,7 @@ EXPORT_SYMBOL(up_write); void downgrade_write(struct rw_semaphore *sem) { lock_downgrade(&sem->dep_map, _RET_IP_); + DEBUG_RWSEMS_WARN_ON(sem->owner != current); rwsem_set_reader_owned(sem); __downgrade_write(sem); @@ -211,6 +214,7 @@ EXPORT_SYMBOL(down_write_killable_nested); void up_read_non_owner(struct rw_semaphore *sem) { + DEBUG_RWSEMS_WARN_ON(sem->owner != RWSEM_READER_OWNED); __up_read(sem); } |