[PATCH v3] sched: unlikely corrupted stack end

WANG Chao
2016-06-15T08:54:03Z

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