From 047106adcc85e3023da210143a6ab8a55df9e0fc Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 16 Nov 2009 10:28:09 +0100 Subject: [PATCH] sched: Sched_rt_periodic_timer vs cpu hotplug Heiko reported a case where a timer interrupt managed to reference a root_domain structure that was already freed by a concurrent hot-un-plug operation. Solve this like the regular sched_domain stuff is also synchronized, by adding a synchronize_sched() stmt to the free path, this ensures that a root_domain stays present for any atomic section that could have observed it. Reported-by: Heiko Carstens Signed-off-by: Peter Zijlstra Acked-by: Heiko Carstens Cc: Gregory Haskins Cc: Siddha Suresh B Cc: Martin Schwidefsky LKML-Reference: <1258363873.26714.83.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/sched.c b/kernel/sched.c index cea2beac7909..3c91f110fc62 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7912,6 +7912,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) static void free_rootdomain(struct root_domain *rd) { + synchronize_sched(); + cpupri_cleanup(&rd->cpupri); free_cpumask_var(rd->rto_mask); -- 2.20.1