From: Andy Lutomirski <luto@xxxxxxxxxx>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit 252d2a4117bc181b287eeddf848863788da733ae ]
idle_task_exit() can be called with IRQs on x86 on and therefore
should use switch_mm(), not switch_mm_irqs_off().
This doesn't seem to cause any problems right now, but it will
confuse my upcoming TLB flush changes. Nonetheless, I think it
should be backported because it's trivial. There won't be any
meaningful performance impact because idle_task_exit() is only
used when offlining a CPU.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler")
Link: http://lkml.kernel.org/r/ca3d1a9fa93a0b49f5a8ff729eda3640fb6abdf9.1497034141.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d253618d09c6..9c905bd94ff0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4979,7 +4979,7 @@ void idle_task_exit(void)
BUG_ON(cpu_online(smp_processor_id()));
if (mm != &init_mm) {
- switch_mm_irqs_off(mm, &init_mm, current);
+ switch_mm(mm, &init_mm, current);
finish_arch_post_lock_switch();
}
mmdrop(mm);
--
2.14.1