Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756161AbdGXRUN (ORCPT ); Mon, 24 Jul 2017 13:20:13 -0400 Received: from mail-pf0-f182.google.com ([209.85.192.182]:36264 "EHLO mail-pf0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753400AbdGXRUF (ORCPT ); Mon, 24 Jul 2017 13:20:05 -0400 From: Greg Hackmann To: John Stultz , Thomas Gleixner Cc: Ben Fennema , linux-kernel@vger.kernel.org, Greg Hackmann , stable@vger.kernel.org Subject: [PATCH] alarmtimer: don't rate limit one-shot timers Date: Mon, 24 Jul 2017 10:19:24 -0700 Message-Id: <20170724171924.27898-1-ghackmann@google.com> X-Mailer: git-send-email 2.14.0.rc0.284.gd933b75aa4-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1275 Lines: 32 Commit ff86bf0c65f1 ("alarmtimer: Rate limit periodic intervals") sets a minimum bound on the alarm timer interval. This minimum bound shouldn't be applied if the interval is 0. Otherwise, one-shot timers will be converted into periodic ones. This patch is against 4.9.39, and is only needed in -stable trees. 4.13-rc2 isn't impacted due to a later refactoring. Fixes: ff86bf0c65f1 ("alarmtimer: Rate limit periodic intervals") Reported-by: Ben Fennema Signed-off-by: Greg Hackmann Cc: stable@vger.kernel.org --- kernel/time/alarmtimer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 9ba04aa740b9..d67ef56ca9bc 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -629,7 +629,8 @@ static int alarm_timer_set(struct k_itimer *timr, int flags, * Rate limit to the tick as a hot fix to prevent DOS. Will be * mopped up later. */ - if (ktime_to_ns(timr->it.alarm.interval) < TICK_NSEC) + if (timr->it.alarm.interval.tv64 && + ktime_to_ns(timr->it.alarm.interval) < TICK_NSEC) timr->it.alarm.interval = ktime_set(0, TICK_NSEC); exp = timespec_to_ktime(new_setting->it_value); -- 2.14.0.rc0.284.gd933b75aa4-goog