diff options
| author | Gvozden Neskovic <[email protected]> | 2017-08-03 05:42:58 +0200 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2017-08-02 20:42:58 -0700 |
| commit | 261a3151e16851304eb3e36af2681d1d1579b08f (patch) | |
| tree | e7862bd56808c2591737ff6eed319dc345f65c24 /include | |
| parent | 549423c0d4b8176110283a5cf90c6393b2a537d4 (diff) | |
spl-mutex: fix race in mutex_exit
Prevent race on accessing kmutex_t when the mutex is
embedded in a ref counted structure.
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Chunwei Chen <[email protected]>
Signed-off-by: Gvozden Neskovic <[email protected]>
Closes zfsonlinux/zfs#6401
Closes #637
Diffstat (limited to 'include')
| -rw-r--r-- | include/sys/mutex.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/sys/mutex.h b/include/sys/mutex.h index 319235223..8a98a9213 100644 --- a/include/sys/mutex.h +++ b/include/sys/mutex.h @@ -183,12 +183,13 @@ spl_mutex_lockdep_on_maybe(kmutex_t *mp) \ */ #define mutex_exit(mp) \ { \ - spl_mutex_lockdep_off_maybe(mp); \ - spin_lock(&(mp)->m_lock); \ spl_mutex_clear_owner(mp); \ + spin_lock(&(mp)->m_lock); \ + spl_mutex_lockdep_off_maybe(mp); \ mutex_unlock(MUTEX(mp)); \ - spin_unlock(&(mp)->m_lock); \ spl_mutex_lockdep_on_maybe(mp); \ + spin_unlock(&(mp)->m_lock); \ + /* NOTE: do not dereference mp after this point */ \ } int spl_mutex_init(void); |