[PATCH] Ftrace: irqsoff tracer may cause stack overflow

[Li Yi]

"irqsoff" tracer may cause stack overflow on architectures using
asm-generic/atomic.h, due to recursive invoking of, e.g.
trace_hardirqs_off().

trace_hardirqs_off() -> start_critical_timing() -> atomic_inc() ->
atomic_add_return() -> local_irq_save() -> trace_hardirqs_off()

Signed-off-by: Yi Li <yi.li@xxxxxxxxxx>
---
 include/asm-generic/atomic.h |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index c99c64d..c3e5f4b 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -60,11 +60,11 @@ static inline int atomic_add_return(int i, atomic_t
*v)
 	unsigned long flags;
 	int temp;
 
-	local_irq_save(flags);
+	raw_local_irq_save(flags);
 	temp = v->counter;
 	temp += i;
 	v->counter = temp;
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 
 	return temp;
 }
@@ -82,11 +82,11 @@ static inline int atomic_sub_return(int i, atomic_t
*v)
 	unsigned long flags;
 	int temp;
 
-	local_irq_save(flags);
+	raw_local_irq_save(flags);
 	temp = v->counter;
 	temp -= i;
 	v->counter = temp;
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 
 	return temp;
 }
@@ -139,9 +139,9 @@ static inline void atomic_clear_mask(unsigned long
mask, unsigned long *addr)
 	unsigned long flags;
 
 	mask = ~mask;
-	local_irq_save(flags);
+	raw_local_irq_save(flags);
 	*addr &= mask;
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 }
 
 #define atomic_xchg(ptr, v)		(xchg(&(ptr)->counter, (v)))
-- 
1.6.0.4


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