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| author | Mateusz Guzik <mjg@FreeBSD.org> | 2017-02-09 13:32:19 +0000 |
|---|---|---|
| committer | Mateusz Guzik <mjg@FreeBSD.org> | 2017-02-09 13:32:19 +0000 |
| commit | 8eaaf58a5f62fc8fcce50c619d34b58e6957e67c (patch) | |
| tree | 381934479df07c4a76c6f9f632d807ef880039bc /sys/kern/kern_rwlock.c | |
| parent | 3b3cf014fc98c3e3193ae117c22b60526545275d (diff) | |
| download | src-8eaaf58a5f62fc8fcce50c619d34b58e6957e67c.tar.gz src-8eaaf58a5f62fc8fcce50c619d34b58e6957e67c.zip | |
rwlock: fix r313454
The runlock slow path would update wrong variable before restarting the
loop, in effect corrupting the state.
Reported by: pho
Notes
Notes:
svn path=/head/; revision=313472
Diffstat (limited to 'sys/kern/kern_rwlock.c')
| -rw-r--r-- | sys/kern/kern_rwlock.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sys/kern/kern_rwlock.c b/sys/kern/kern_rwlock.c index be1c42e8ee0a..9464588b9eda 100644 --- a/sys/kern/kern_rwlock.c +++ b/sys/kern/kern_rwlock.c @@ -755,7 +755,7 @@ __rw_runlock_hard(volatile uintptr_t *c, struct thread *td, uintptr_t v, if (!atomic_cmpset_rel_ptr(&rw->rw_lock, RW_READERS_LOCK(1) | v, x)) { turnstile_chain_unlock(&rw->lock_object); - x = RW_READ_VALUE(rw); + v = RW_READ_VALUE(rw); continue; } if (LOCK_LOG_TEST(&rw->lock_object, 0)) |