UPSTREAM: sched: panic on corrupted stack end

(cherry picked from commit 29d6455178a09e1dc340380c582b13356227e8df)

Until now, hitting this BUG_ON caused a recursive oops (because oops
handling involves do_exit(), which calls into the scheduler, which in
turn raises an oops), which caused stuff below the stack to be
overwritten until a panic happened (e.g.  via an oops in interrupt
context, caused by the overwritten CPU index in the thread_info).

Just panic directly.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Ia3acb3f747f7a58ec2d071644433b0591925969f
Bug: 29444228
This commit is contained in:
Jann Horn 2016-06-01 11:55:07 +02:00 committed by Min Chong
parent ed23e11450
commit 85a09f2732

View file

@ -3008,7 +3008,8 @@ static noinline void __schedule_bug(struct task_struct *prev)
static inline void schedule_debug(struct task_struct *prev) static inline void schedule_debug(struct task_struct *prev)
{ {
#ifdef CONFIG_SCHED_STACK_END_CHECK #ifdef CONFIG_SCHED_STACK_END_CHECK
BUG_ON(task_stack_end_corrupted(prev)); if (task_stack_end_corrupted(prev))
panic("corrupted stack end detected inside scheduler\n");
#endif #endif
if (unlikely(in_atomic_preempt_off())) { if (unlikely(in_atomic_preempt_off())) {