From: Chen Gang <gang.chen@asianux•com>
To: Michael Ellerman <michael@ellerman•id.au>
Cc: Michael Neuling <mikey@neuling•org>,
"paulus@samba•org" <paulus@samba•org>,
Andrew Morton <akpm@linux-foundation•org>,
"linuxppc-dev@lists•ozlabs.org" <linuxppc-dev@lists•ozlabs.org>,
jovi.zhangwei@huawei•com
Subject: Re: [Suggestion] powerpc: xmon: about 'longjmp' related warning.
Date: Wed, 24 Jul 2013 08:38:21 +0800 [thread overview]
Message-ID: <51EF21FD.9020509@asianux.com> (raw)
In-Reply-To: <20130723135809.GG31944@concordia>
On 07/23/2013 09:58 PM, Michael Ellerman wrote:
> On Mon, Jul 22, 2013 at 03:02:53PM +0800, Chen Gang wrote:
>> Hello Maintainers:
>>
>> With allmodconfig and EXTRA_CFLAGS=-W", it reports warnings below:
>
>>
>> arch/powerpc/xmon/xmon.c:3027:6: warning: variable ‘i’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered]
>> arch/powerpc/xmon/xmon.c:3068:6: warning: variable ‘i’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered]
>
> In both these cases we are inside the body of a for loop and we do a
> if (setjmp) / else block. Although looking at the source the value of i
> is not modified by the setjmp, I guess it's possible that the compiler
> might reorder the increment of i inside the setjmp and loose the value
> when we longjmp.
>
I should continue to confirm the details based on your valuable
information, thanks.
>> arch/powerpc/xmon/xmon.c:352:48: warning: argument ‘fromipi’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered]
>
> This one I can't see, but I assume it's a similar case.
>
OK, I should continue for it.
>> Excuse me, I am not quite sure about it whether can cause issue or not.
>
> I've never seen it get stuck in those loops or anything, but I guess
> it's possible.
>
OK, I should make the confirmation.
> The first thing to do would be to analyse the generated assembler code
> to determine if there really is any possiblity of the value being
> clobbered, or if it's just a theoretical bug.
>
Thank you for your valuable information again.
Excuse me, I have to do another things within this month, so I should
provide the confirmation within next month (2013-08-31), is it OK (no
reply means OK).
Welcome any suggestions or completions.
Thanks.
--
Chen Gang
next prev parent reply other threads:[~2013-07-24 0:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-22 7:02 [Suggestion] powerpc: xmon: about 'longjmp' related warning Chen Gang
2013-07-23 13:58 ` Michael Ellerman
2013-07-24 0:38 ` Chen Gang [this message]
2013-07-26 4:11 ` Chen Gang
2013-07-26 11:45 ` Chen Gang
2013-07-26 11:47 ` Chen Gang
2013-07-26 11:55 ` Chen Gang
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