Commit 4fa5cd52 authored Sep 13, 2016 by Con Kolivas Committed by Ingo Molnar Sep 22, 2016

sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn()



We should not be using smp_processor_id() with preempt enabled.

Bug identified and fix provided by Alfred Chen.

Reported-by: Alfred Chen <cchalpha@gmail.com>
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Alfred Chen <cchalpha@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/2042051.3vvUWIM0vs@hex


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent d59dc7bc

kernel/smpboot.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -122,12 +122,12 @@ static int smpboot_thread_fn(void *data)

		if (kthread_should_park()) {
		__set_current_state(TASK_RUNNING);
		preempt_enable();
		if (ht->park && td->status == HP_THREAD_ACTIVE) {
		BUG_ON(td->cpu != smp_processor_id());
		ht->park(td->cpu);
		td->status = HP_THREAD_PARKED;
		}
		preempt_enable();
		kthread_parkme();
		/* We might have been woken for stop */
		continue;