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From: "Américo Wang" <xiyou.wangcong@gmail.com>
To: Jan Beulich <JBeulich@novell.com>
Cc: mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86: suppress stack overrun message for init_task
Date: Sat, 21 Nov 2009 18:17:09 +0800	[thread overview]
Message-ID: <20091121101709.GC2412@hack> (raw)
In-Reply-To: <4B06AEFE02000078000211F4@vpn.id2.novell.com>

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@novell.com>
>

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;
>
>
>
>--
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-- 
Live like a child, think like the god.
 

  reply	other threads:[~2009-11-21 10:21 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-20 14:00 [PATCH] x86: suppress stack overrun message for init_task Jan Beulich
2009-11-21 10:17 ` Américo Wang [this message]
2009-11-21 10:31 ` Américo Wang
2009-11-23  8:41   ` Jan Beulich
2009-11-23 11:53 ` [tip:x86/debug] x86: Suppress " tip-bot for Jan Beulich

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