From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35229) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmntq-0004c3-8m for qemu-devel@nongnu.org; Wed, 21 Sep 2016 16:13:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bmnto-0002Mi-7Y for qemu-devel@nongnu.org; Wed, 21 Sep 2016 16:13:45 -0400 From: P J P Date: Thu, 22 Sep 2016 01:43:27 +0530 Message-Id: <1474488807-451-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH] timer: a9gtimer: check auto-increment register value List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Peter Maydell , Li Qiang , qemu-arm@nongnu.org, Prasad J Pandit From: Prasad J Pandit ARM A9MP processor has a peripheral timer with an auto-increment register, which holds an increment step value. A user could set this value to zero, when auto-increment control bit is enabled. This leads to an infinite loop in 'a9_gtimer_update' while updating comparator value. Add check to avoid it. Reported-by: Li Qiang Signed-off-by: Prasad J Pandit --- hw/timer/a9gtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/timer/a9gtimer.c b/hw/timer/a9gtimer.c index 772f85f..3f752ce 100644 --- a/hw/timer/a9gtimer.c +++ b/hw/timer/a9gtimer.c @@ -85,7 +85,7 @@ static void a9_gtimer_update(A9GTimerState *s, bool sync) while (gtb->compare < update.new) { DB_PRINT("Compare event happened for CPU %d\n", i); gtb->status = 1; - if (gtb->control & R_CONTROL_AUTO_INCREMENT) { + if (gtb->inc && gtb->control & R_CONTROL_AUTO_INCREMENT) { DB_PRINT("Auto incrementing timer compare by %" PRId32 "\n", gtb->inc); gtb->compare += gtb->inc; -- 2.5.5