From: deraadt <deraadt@openbsd.org>
Date: Sun, 9 Apr 2017 15:47:18 +0000 (+0000)
Subject: Correct wakeup() dance in sensor_task_work()
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=fbfda7f8ad4bf2a83d91280caedf38fdd000667a;p=openbsd

Correct wakeup() dance in sensor_task_work()
Problem noticed by krw
---

diff --git a/sys/kern/kern_sensors.c b/sys/kern/kern_sensors.c
index 7cbe4019388..48c0fb096f0 100644
--- a/sys/kern/kern_sensors.c
+++ b/sys/kern/kern_sensors.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sensors.c,v 1.37 2017/04/08 04:06:01 deraadt Exp $	*/
+/*	$OpenBSD: kern_sensors.c,v 1.38 2017/04/09 15:47:18 deraadt Exp $	*/
 
 /*
  * Copyright (c) 2005 David Gwynne <dlg@openbsd.org>
@@ -263,8 +263,10 @@ sensor_task_work(void *xst)
 	if (period > 0 && !sensors_quiesced)
 		st->func(st->arg);
 	rw_exit_write(&st->lock);
-	if (sensors_quiesced && atomic_dec_int_nv(&sensors_running) == 0)
-		wakeup(&sensors_running);
+	if (atomic_dec_int_nv(&sensors_running) == 0) {
+		if (sensors_quiesced)
+			wakeup(&sensors_running);
+	}
 
 	if (period == 0)
 		free(st, M_DEVBUF, sizeof(*st));