linux-kernel - Re: [PATCH 2.6.25-rc5] x86: correct/clarify comment in nops.h

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Tue, 11 Mar 2008 17:19:05 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Mikael Pettersson <mikpe@...uu.se>
Cc:	tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2.6.25-rc5] x86: correct/clarify comment in nops.h


* Mikael Pettersson <mikpe@...uu.se> wrote:

> <asm-x86/nops.h> describes certain multibyte instructions as "generic" 
> nops when in fact they aren't nops at all in 64-bit mode (missing 
> REX.W causing truncation of a register).
> 
> Update the comment to state that K8 or P6 style nops should be used in 
> 64-bit mode. This matches what the alternatives code does.

>  /* generic versions from gas
>     1: nop
> +   the following instructions are NOT nops in 64-bit mode,
> +   for 64-bit mode use K8 or P6 nops instead
>     2: movl %esi,%esi
>     3: leal 0x00(%esi),%esi
>     4: leal 0x00(,%esi,1),%esi

thanks Mikael, applied.

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/