Messages in this thread Patch in this message | | | Date | Tue, 16 Dec 2014 16:25:28 -0600 | From | Eric Sandeen <> | Subject | [PATCH] check for stack overflow in ___might_sleep |
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Sometimes a "BUG: sleeping function called from invalid context" message is not indicative of locking problems, but is the result of a stack overflow corrupting the thread info.
Witness http://oss.sgi.com/archives/xfs/2014-02/msg00325.html for example, which took a few go-rounds to sort out.
If we're printing the warning, things are wonky already, and it'd be informative to check for the stack end corruption at this point, too.
Signed-off-by: Eric Sandeen <sandeen@redhat.com> ---
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b5797b7..4ef726c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7328,6 +7328,9 @@ void ___might_sleep(const char *file, int line, int preempt_offset) in_atomic(), irqs_disabled(), current->pid, current->comm); + if (task_stack_end_corrupted(current)) + printk(KERN_EMERG "Thread overran stack, or stack corrupted\n"); + debug_show_held_locks(current); if (irqs_disabled()) print_irqtrace_events(current);
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