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From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
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
Date: Wed, 12 Nov 2008 10:34:35 -0800	[thread overview]
Message-ID: <491B21BB.5080001@ct.jp.nec.com> (raw)
In-Reply-To: <878wrpdrwq.fsf@basil.nowhere.org>

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

      reply	other threads:[~2008-11-12 18:34 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-12  3:09 [PATCH 1/2] x86: signal_32: introduce retcode and rt_retcode Hiroshi Shimamoto
2008-11-12  3:11 ` [PATCH 2/2] x86: ia32_signal: remove unnecessary padding Hiroshi Shimamoto
2008-11-12 11:29   ` Ingo Molnar
2008-11-12 12:33     ` Mikael Pettersson
2008-11-12 17:12       ` H. Peter Anvin
2008-11-12 18:02         ` Hiroshi Shimamoto
2008-11-12 18:12           ` H. Peter Anvin
2008-11-13  8:45             ` Mikael Pettersson
2008-11-13 17:38               ` H. Peter Anvin
2008-11-12 12:56   ` Andi Kleen
2008-11-12 18:34     ` Hiroshi Shimamoto [this message]

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