diff options
| author | lstewart <lstewart@FreeBSD.org> | 2013-06-17 09:49:07 +0000 |
|---|---|---|
| committer | lstewart <lstewart@FreeBSD.org> | 2013-06-17 09:49:07 +0000 |
| commit | 4f358ad954443ab3df8ac3ddda5deb7fba336584 (patch) | |
| tree | 5dea88510b2e37a46af34894f51d5fb71274d4ff /sys/kern/kern_alq.c | |
| parent | 95ba85598a3f78e22697c60c43da43d596b594e9 (diff) | |
| download | FreeBSD-src-4f358ad954443ab3df8ac3ddda5deb7fba336584.zip FreeBSD-src-4f358ad954443ab3df8ac3ddda5deb7fba336584.tar.gz | |
The fix committed in r250951 replaced the reported panic with a deadlock... gold
star for me. EVENTHANDLER_DEREGISTER() attempts to acquire the lock which is
held by the event handler framework while executing event handler functions,
leading to deadlock.
Move EVENTHANDLER_DEREGISTER() to alq_load_handler() and thus deregister the ALQ
shutdown_pre_sync handler at module unload time, which takes care of the
originally reported panic and fixes the deadlock introduced in r250951.
Reported by: Luiz Otavio O Souza
MFC after: 3 days
X-MFC with: 250951
Diffstat (limited to 'sys/kern/kern_alq.c')
| -rw-r--r-- | sys/kern/kern_alq.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sys/kern/kern_alq.c b/sys/kern/kern_alq.c index daf4e46..1e6fcf7 100644 --- a/sys/kern/kern_alq.c +++ b/sys/kern/kern_alq.c @@ -229,8 +229,6 @@ ald_shutdown(void *arg, int howto) { struct alq *alq; - EVENTHANDLER_DEREGISTER(shutdown_pre_sync, alq_eventhandler_tag); - ALD_LOCK(); /* Ensure no new queues can be created. */ @@ -938,6 +936,8 @@ alq_load_handler(module_t mod, int what, void *arg) if (LIST_FIRST(&ald_queues) == NULL) { ald_shutingdown = 1; ALD_UNLOCK(); + EVENTHANDLER_DEREGISTER(shutdown_pre_sync, + alq_eventhandler_tag); ald_shutdown(NULL, 0); mtx_destroy(&ald_mtx); } else { |
