From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [PATCH RT 09/13] kernel/hrtimer: migrate deferred timer on CPU down Date: Wed, 17 Jan 2018 10:14:13 -0500 Message-ID: <20180117151431.888304466@goodmis.org> References: <20180117151404.093229667@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker , Julia Cartwright , Daniel Wagner , tom.zanussi@linux.intel.com, Alex Shi , stable-rt@vger.kernel.org, Mike Galbraith To: linux-kernel@vger.kernel.org, linux-rt-users Return-path: Content-Disposition: inline; filename=0009-kernel-hrtimer-migrate-deferred-timer-on-CPU-down.patch Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org 3.18.91-rt98-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior hrtimers, which were deferred to the softirq context, and expire between softirq shutdown and hrtimer migration are dangling around. If the CPU goes back up the list head will be initialized and this corrupts the timer's list. It will remain unnoticed until a hrtimer_cancel(). This moves those timers so they will expire. Cc: stable-rt@vger.kernel.org Reported-by: Mike Galbraith Tested-by: Mike Galbraith Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- kernel/time/hrtimer.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 2c1597d2bd6d..2e869c707628 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1959,6 +1959,11 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, /* Clear the migration state bit */ timer->state &= ~HRTIMER_STATE_MIGRATE; } +#ifdef CONFIG_PREEMPT_RT_BASE + list_splice_tail(&old_base->expired, &new_base->expired); + if (!list_empty(&new_base->expired)) + raise_softirq_irqoff(HRTIMER_SOFTIRQ); +#endif } static void migrate_hrtimers(int scpu) -- 2.13.2