diff options
| author | Luc Michel <luc.michel@greensocs.com> | 2020-01-29 15:49:48 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-02-12 16:23:01 +0100 |
| commit | e261b36810de8dfd825b6b01fff43a6bd6f2bd8d (patch) | |
| tree | d8a8e292d9ae86b78c4560e849e79098766a8264 /include | |
| parent | 4903602eae82787b1ade04efd9bb5949c04571d6 (diff) | |
seqlock: fix seqlock_write_unlock_impl function
The seqlock write unlock function was incorrectly calling
seqlock_write_begin() instead of seqlock_write_end(), and was releasing
the lock before incrementing the sequence. This could lead to a race
condition and a corrupted sequence number becoming odd even though the
lock is not held.
Signed-off-by: Luc Michel <luc.michel@greensocs.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200129144948.2161551-1-luc.michel@greensocs.com>
Fixes: 988fcafc73 ("seqlock: add QemuLockable support", 2018-08-23)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/qemu/seqlock.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/qemu/seqlock.h b/include/qemu/seqlock.h index fd408b7ec5..8b6b4ee4bb 100644 --- a/include/qemu/seqlock.h +++ b/include/qemu/seqlock.h @@ -55,11 +55,11 @@ static inline void seqlock_write_lock_impl(QemuSeqLock *sl, QemuLockable *lock) #define seqlock_write_lock(sl, lock) \ seqlock_write_lock_impl(sl, QEMU_MAKE_LOCKABLE(lock)) -/* Lock out other writers and update the count. */ +/* Update the count and release the lock. */ static inline void seqlock_write_unlock_impl(QemuSeqLock *sl, QemuLockable *lock) { + seqlock_write_end(sl); qemu_lockable_unlock(lock); - seqlock_write_begin(sl); } #define seqlock_write_unlock(sl, lock) \ seqlock_write_unlock_impl(sl, QEMU_MAKE_LOCKABLE(lock)) |