diff options
| author | jhb <jhb@FreeBSD.org> | 2006-04-17 18:20:38 +0000 |
|---|---|---|
| committer | jhb <jhb@FreeBSD.org> | 2006-04-17 18:20:38 +0000 |
| commit | d535a5cb818e93fdb882b2748621d7367c013113 (patch) | |
| tree | 6e1e68443c878ae084bc35e7e36a8edf68ad3352 /sys/kern/kern_umtx.c | |
| parent | b4b950d049176bd4834f960bca79c4a2bdfd88c4 (diff) | |
| download | FreeBSD-src-d535a5cb818e93fdb882b2748621d7367c013113.zip FreeBSD-src-d535a5cb818e93fdb882b2748621d7367c013113.tar.gz | |
Change msleep() and tsleep() to not alter the calling thread's priority
if the specified priority is zero. This avoids a race where the calling
thread could read a snapshot of it's current priority, then a different
thread could change the first thread's priority, then the original thread
would call sched_prio() inside msleep() undoing the change made by the
second thread. I used a priority of zero as no thread that calls msleep()
or tsleep() should be specifying a priority of zero anyway.
The various places that passed 'curthread->td_priority' or some variant
as the priority now pass 0.
Diffstat (limited to 'sys/kern/kern_umtx.c')
| -rw-r--r-- | sys/kern/kern_umtx.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/sys/kern/kern_umtx.c b/sys/kern/kern_umtx.c index 672add3..a4ee457 100644 --- a/sys/kern/kern_umtx.c +++ b/sys/kern/kern_umtx.c @@ -168,7 +168,7 @@ umtxq_busy(struct umtx_key *key) while (umtxq_chains[chain].uc_flags & UCF_BUSY) { umtxq_chains[chain].uc_flags |= UCF_WANT; msleep(&umtxq_chains[chain], umtxq_mtx(chain), - curthread->td_priority, "umtxq_busy", 0); + 0, "umtxq_busy", 0); } umtxq_chains[chain].uc_flags |= UCF_BUSY; } @@ -424,8 +424,7 @@ _do_lock(struct thread *td, struct umtx *umtx, long id, int timo) */ umtxq_lock(&uq->uq_key); if (old == owner && (td->td_flags & TDF_UMTXQ)) { - error = umtxq_sleep(td, &uq->uq_key, - td->td_priority | PCATCH, + error = umtxq_sleep(td, &uq->uq_key, PCATCH, "umtx", timo); } umtxq_busy(&uq->uq_key); @@ -547,7 +546,7 @@ do_wait(struct thread *td, struct umtx *umtx, long id, struct timespec *timeout) umtxq_lock(&uq->uq_key); if (td->td_flags & TDF_UMTXQ) error = umtxq_sleep(td, &uq->uq_key, - td->td_priority | PCATCH, "ucond", 0); + PCATCH, "ucond", 0); if (!(td->td_flags & TDF_UMTXQ)) error = 0; else @@ -560,8 +559,7 @@ do_wait(struct thread *td, struct umtx *umtx, long id, struct timespec *timeout) for (;;) { umtxq_lock(&uq->uq_key); if (td->td_flags & TDF_UMTXQ) { - error = umtxq_sleep(td, &uq->uq_key, - td->td_priority | PCATCH, + error = umtxq_sleep(td, &uq->uq_key, PCATCH, "ucond", tvtohz(&tv)); } if (!(td->td_flags & TDF_UMTXQ)) { |
