diff options
| author | Brian Behlendorf <[email protected]> | 2012-08-19 12:10:19 -0700 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2012-08-27 12:00:55 -0700 |
| commit | 3e904f40b4f24db61798ca8c8a9027731cf2ced6 (patch) | |
| tree | c125889abf40608464a3a5c6840301755c967b2a | |
| parent | eb0f407a2b9089113ef6f2402ebd887511315b43 (diff) | |
Mutex ASSERT on self deadlock
Generate an assertion if we're going to deadlock the system by
attempting to acquire a mutex the process is already holding.
There are currently no known instances of this under normal
operation, but it _might_ be possible when using a ZVOL as a
swap device. I want to ensure we catch this immediately if it
were to occur.
Signed-off-by: Brian Behlendorf <[email protected]>
| -rw-r--r-- | include/sys/mutex.h | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/include/sys/mutex.h b/include/sys/mutex.h index 213bc2477..905eed50e 100644 --- a/include/sys/mutex.h +++ b/include/sys/mutex.h @@ -78,8 +78,12 @@ mutex_owner(kmutex_t *mp) }) #define mutex_tryenter(mp) mutex_trylock(&(mp)->m) -#define mutex_enter(mp) mutex_lock(&(mp)->m) -#define mutex_exit(mp) mutex_unlock(&(mp)->m) +#define mutex_enter(mp) \ +({ \ + ASSERT3P(mutex_owner(mp), !=, current); \ + mutex_lock(&(mp)->m); \ + }) +#define mutex_exit(mp) mutex_unlock(&(mp)->m) #ifdef HAVE_GPL_ONLY_SYMBOLS # define mutex_enter_nested(mp, sc) mutex_lock_nested(&(mp)->m, sc) @@ -171,6 +175,7 @@ spl_mutex_clear_owner(kmutex_t *mp) _rc_ = 0; \ _count_ = 0; \ _owner_ = mutex_owner(mp); \ + ASSERT3P(_owner_, !=, current); \ \ while (_owner_ && task_curr(_owner_) && \ _count_ <= spl_mutex_spin_max()) { \ |