Re: [PATCH] Ftrace: irqsoff tracer may cause stack overflow

From: Li Yi
Date: Fri Jan 08 2010 - 01:25:43 EST


On Thu, 2010-01-07 at 23:54 -0500, Mike Frysinger wrote:
> > @@ -60,11 +60,11 @@ static inline int atomic_add_return(int i, atomic_t
> > *v)
> > @@ -82,11 +82,11 @@ static inline int atomic_sub_return(int i, atomic_t
> > *v)
> > @@ -139,9 +139,9 @@ static inline void atomic_clear_mask(unsigned long
> > mask, unsigned long *addr)
>
> looks like your mailer has line wrapping problems ... might want to
> fix that. maybe just find a smtp server in ADI shanghai's office to
> send to and use sendemail.smtpersver in your ~/.gitconfig ?
> -mike
>

Thanks. Disabled auto-wrap and resend:

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