[PATCH v3] sched: unlikely corrupted stack end

From	WANG Chao <wcwxyz@gmail.com>
Newsgroups	linux.kernel
Subject	[PATCH v3] sched: unlikely corrupted stack end
Date	2016-06-15 11:00 +0200
Message-ID	<rKeQ2-iF-9@gated-at.bofh.it> (permalink)
References	<rKen0-6S-29@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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unlikely() was dropped in commit ce03e4137bb2 ("sched/core: Drop
unlikely behind BUG_ON()"), but commit 29d6455178a0 ("sched: panic on
corrupted stack end") dropped BUG_ON() and called panic directly.

Now we should bring unlikely() back for branch prediction. While we're
at it, it's better and cleaner to add unlikely() to
task_stack_end_corrupted() macro.

Signed-off-by: WANG Chao <wcwxyz@gmail.com>
---
 include/linux/sched.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6e42ada26345..74a02bf30827 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2998,7 +2998,7 @@ static inline unsigned long *end_of_stack(struct task_struct *p)
 
 #endif
 #define task_stack_end_corrupted(task) \
-		(*(end_of_stack(task)) != STACK_END_MAGIC)
+		(unlikely(*(end_of_stack(task)) != STACK_END_MAGIC))
 
 static inline int object_is_on_stack(void *obj)
 {
-- 
2.9.0

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[PATCH] sched: unlikely corrupted stack end WANG Chao <wcwxyz@gmail.com> - 2016-06-14 08:50 +0200
  Re: [PATCH] sched: unlikely corrupted stack end Ingo Molnar <mingo@kernel.org> - 2016-06-14 09:50 +0200
  Re: [PATCH] sched: unlikely corrupted stack end Peter Zijlstra <peterz@infradead.org> - 2016-06-14 10:20 +0200
  [PATCH v2] sched: unlikely corrupted stack end WANG Chao <wcwxyz@gmail.com> - 2016-06-14 10:30 +0200
    Re: [PATCH v2] sched: unlikely corrupted stack end Ingo Molnar <mingo@kernel.org> - 2016-06-14 11:00 +0200
      Re: [PATCH v2] sched: unlikely corrupted stack end WANG Chao <wcwxyz@gmail.com> - 2016-06-14 12:20 +0200
        Re: [PATCH v2] sched: unlikely corrupted stack end Ingo Molnar <mingo@kernel.org> - 2016-06-14 12:30 +0200
          Re: [PATCH v2] sched: unlikely corrupted stack end WANG Chao <wcwxyz@gmail.com> - 2016-06-14 19:00 +0200
            Re: [PATCH v2] sched: unlikely corrupted stack end Ingo Molnar <mingo@kernel.org> - 2016-06-15 10:30 +0200
              [PATCH v3] sched: unlikely corrupted stack end WANG Chao <wcwxyz@gmail.com> - 2016-06-15 11:00 +0200

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