From 24bfcb100959c8641a627b5604d967243f8f240c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 26 Jun 2015 22:08:38 +0200 Subject: [PATCH] timer: Fix hotplug regression The recent timer wheel rework removed the get/put_cpu_var() pair in the hotplug migration code, which results in: BUG: using smp_processor_id() in preemptible [00000000] code: hib.sh/2845 ... [] timer_cpu_notify+0x53/0x12 That hunk is a leftover from an earlier iteration and went unnoticed so far. Restore the previous code which was obviously correct. Fixes: 0eeda71bc30d 'timer: Replace timer base by a cpu index' Reported-and_tested-by: Borislav Petkov Signed-off-by: Thomas Gleixner --- kernel/time/timer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 520499dd85af..5e097fa9faf7 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1566,7 +1566,7 @@ static void migrate_timers(int cpu) BUG_ON(cpu_online(cpu)); old_base = per_cpu_ptr(&tvec_bases, cpu); - new_base = this_cpu_ptr(&tvec_bases); + new_base = get_cpu_ptr(&tvec_bases); /* * The caller is globally serialized and nobody else * takes two locks at once, deadlock is not possible. @@ -1590,6 +1590,7 @@ static void migrate_timers(int cpu) spin_unlock(&old_base->lock); spin_unlock_irq(&new_base->lock); + put_cpu_ptr(&tvec_bases); } static int timer_cpu_notify(struct notifier_block *self,