linux-kernel - Re: [PATCH] fix dubious segment register clear in cpu

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:	Fri, 4 Aug 2006 02:23:49 +0200
From:	Andi Kleen <ak@...e.de>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	Andrew Morton <akpm@...l.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] fix dubious segment register clear in cpu_init()

On Friday 04 August 2006 01:49, Jeremy Fitzhardinge wrote:
> Fix a very dubious piece of code in
> arch/i386/kernel/cpu/common.c:cpu_init().  This clears out %fs and
> %gs, but clobbers %eax in the process without telling gcc.  It turns
> out that gcc happens to be not using %eax at that point anyway so it
> doesn't matter much, but it looks like a bomb waiting to go off.
> 
> This does end up saving an instruction, because gcc wants %eax==0 for
> the set_debugreg()s below.

Added thanks

-Andi
-
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/