From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753480AbaFGBcs (ORCPT ); Fri, 6 Jun 2014 21:32:48 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36097 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752644AbaFGBXj (ORCPT ); Fri, 6 Jun 2014 21:23:39 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, arvind.chauhan@arm.com, "Viresh Kumar" , linaro-networking@linaro.org, "Thomas Gleixner" , fweisbec@gmail.com, linaro-kernel@lists.linaro.org Date: Sat, 07 Jun 2014 02:26:29 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 64/92] hrtimer: Set expiry time before switch_hrtimer_base() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Viresh Kumar commit 84ea7fe37908254c3bd90910921f6e1045c1747a upstream. switch_hrtimer_base() calls hrtimer_check_target() which ensures that we do not migrate a timer to a remote cpu if the timer expires before the current programmed expiry time on that remote cpu. But __hrtimer_start_range_ns() calls switch_hrtimer_base() before the new expiry time is set. So the sanity check in hrtimer_check_target() is operating on stale or even uninitialized data. Update expiry time before calling switch_hrtimer_base(). [ tglx: Rewrote changelog once again ] Signed-off-by: Viresh Kumar Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: fweisbec@gmail.com Cc: arvind.chauhan@arm.com Link: http://lkml.kernel.org/r/81999e148745fc51bbcd0615823fbab9b2e87e23.1399882253.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Ben Hutchings --- kernel/hrtimer.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -980,11 +980,8 @@ int __hrtimer_start_range_ns(struct hrti /* Remove an active timer from the queue: */ ret = remove_hrtimer(timer, base); - /* Switch the timer base, if necessary: */ - new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); - if (mode & HRTIMER_MODE_REL) { - tim = ktime_add_safe(tim, new_base->get_time()); + tim = ktime_add_safe(tim, base->get_time()); /* * CONFIG_TIME_LOW_RES is a temporary way for architectures * to signal that they simply return xtime in @@ -999,6 +996,9 @@ int __hrtimer_start_range_ns(struct hrti hrtimer_set_expires_range_ns(timer, tim, delta_ns); + /* Switch the timer base, if necessary: */ + new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); + timer_stats_hrtimer_set_start_info(timer); leftmost = enqueue_hrtimer(timer, new_base);