[PATCH v2] sched: unlikely corrupted stack end

From: WANG Chao
Date: Tue Jun 14 2016 - 04:24:41 EST


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 turn task_stack_end_corrupted() into
inline function.

Signed-off-by: WANG Chao <wcwxyz@xxxxxxxxx>
---
include/linux/sched.h | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6e42ada26345..797ca1975431 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2997,8 +2997,11 @@ 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)
+
+static inline int task_stack_end_corrupted(struct task_struct *p)
+{
+ return unlikely(*(end_of_stack(p)) != STACK_END_MAGIC);
+}

static inline int object_is_on_stack(void *obj)
{
--
2.8.4