linux-kernel - Re: [PATCH] x86: pad assembly functions with INT3

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Date:   Wed, 9 May 2018 12:28:56 -0700
From:   "H. Peter Anvin" <hpa@...or.com>
To:     Alexey Dobriyan <adobriyan@...il.com>
Cc:     tglx@...utronix.de, mingo@...hat.com, linux-kernel@...r.kernel.org,
        x86@...nel.org
Subject: Re: [PATCH] x86: pad assembly functions with INT3

On 05/09/18 09:55, Alexey Dobriyan wrote:
> On Mon, May 07, 2018 at 02:41:14PM -0700, hpa@...or.com wrote:
>>> -#define __ALIGN		.p2align 4, 0x90
>>> +#define __ALIGN		.p2align 4, 0xCC
>>
>> Acked-by: H. Peter Anvin <h.peter.anvin@in tel.com>
> 
> Thanks!
> 
> If someone knows how to control _compiler_ inter-function padding,
> please tell.
> 

I think I have a gcc feature enhancement request for that. It can't be
done without gcc's knowledge of when a fallthrough is happening (I
presume you took that into account in your patch set.)

	-hpa