From a8b686b3af4419f92e0ea5be1c76fb68363df8e6 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Tue, 16 Dec 2014 16:25:28 -0600 Subject: [PATCH] sched/debug: Check for stack overflow in ___might_sleep() 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 Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Link: http://lkml.kernel.org/r/5490B158.4060005@redhat.com Signed-off-by: Ingo Molnar --- kernel/sched/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c0accc00566e..56c9b79772bd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7325,6 +7325,9 @@ 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);