Re: [PATCH] x86: suppress stack overrun message for init_task

[AmÃrico Wang]

On Fri, Nov 20, 2009 at 02:00:14PM +0000, Jan Beulich wrote:
>init_task doesn't get its stack end location set to STACK_END_MAGIC,
>and hence the message is confusing rather than helpful in this case.
>
>Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
>

Yeah, this is a good catch. STACK_END_MAGIC is written in fork(),
init is not forked.

However, isn't it better if we can do the same detection
for init too?


>---
> arch/x86/mm/fault.c |    2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>--- linux-2.6.32-rc8/arch/x86/mm/fault.c
>+++ 2.6.32-rc8-x86-init-task-stack/arch/x86/mm/fault.c
>@@ -658,7 +658,7 @@ no_context(struct pt_regs *regs, unsigne
> 	show_fault_oops(regs, error_code, address);
> 
> 	stackend = end_of_stack(tsk);
>-	if (*stackend != STACK_END_MAGIC)
>+	if (tsk != &init_task && *stackend != STACK_END_MAGIC)
> 		printk(KERN_ALERT "Thread overran stack, or stack corrupted\n");
> 
> 	tsk->thread.cr2		= address;
>
>
>
>--
>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>the body of a message to majordomo@xxxxxxxxxxxxxxx
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>Please read the FAQ at  http://www.tux.org/lkml/

-- 
Live like a child, think like the god.
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/