Message-ID: <491B21BB.5080001@ct.jp.nec.com>
Date: Wed, 12 Nov 2008 10:34:35 -0800
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
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To: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
       "H. Peter Anvin" <hpa@zytor.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] x86: ia32_signal: remove unnecessary padding
References: <491A48E9.8020909@ct.jp.nec.com> <491A496B.5010505@ct.jp.nec.com> <878wrpdrwq.fsf@basil.nowhere.org>
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Andi Kleen wrote:
> Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> writes:
> 
>> From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>>
>> Impact: cleanup
> 
> Actually it's not a cleanup.
> 
>> Remove unnecessary paddings, this saves 4 bytes.
> 
> This might actually break code. The code is not actually used,
> but only kept around because some old gdb versions used this
> code as a marker for detecting signals.

I think, this cleanup doesn't change the code copied to user stack.
It removes additional 2 bytes from each struct, and these had not
been copied to user stack, because the structures were 10 bytes and
frame->retcode is 8 bytes.

Thanks,
Hiroshi Shimamoto
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