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, 2 insertions, 4 deletions

diff --git a/sys/dev/random/randomdev_soft.c b/sys/dev/random/randomdev_soft.c
index cd5e2d9..159d6ce 100644
--- a/sys/dev/random/randomdev_soft.c
+++ b/sys/dev/random/randomdev_soft.c
@@ -211,8 +211,7 @@ random_yarrow_deinit(void)
 	 * Command the hash/reseed thread to end and wait for it to finish
 	 */
 	random_kthread_control = -1;
-	tsleep((void *)&random_kthread_control, curthread->td_priority, "term",
-	    0);
+	tsleep((void *)&random_kthread_control, 0, "term", 0);
 
 	/* Destroy the harvest fifos */
 	while (!STAILQ_EMPTY(&emptyfifo.head)) {
@@ -285,8 +284,7 @@ random_kthread(void *arg __unused)
 
 		/* Found nothing, so don't belabour the issue */
 		if (!active)
-			tsleep(&harvestfifo, curthread->td_priority, "-",
-			    hz / 10);
+			tsleep(&harvestfifo, 0, "-", hz / 10);
 
 	}