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.

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/kern/subr_taskqueue.c b/sys/kern/subr_taskqueue.c
index 00a842d..bd17515 100644
--- a/sys/kern/subr_taskqueue.c
+++ b/sys/kern/subr_taskqueue.c
@@ -365,7 +365,7 @@ taskqueue_thread_loop(void *arg)
 	TQ_LOCK(tq);
 	do {
 		taskqueue_run(tq);
-		TQ_SLEEP(tq, tq, &tq->tq_mutex, curthread->td_priority, "-", 0);
+		TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0);
 	} while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0);
 
 	/* rendezvous with thread that asked us to terminate */