linux-kernel - Re: PATCH] Use -mpreferred-stack-boundary=3 on x86-64 if supported

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

Date:	Sat, 23 Jun 2012 09:17:06 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Andi Kleen <andi@...stfloor.org>, "H.J. Lu" <hjl.tools@...il.com>
CC:	LKML <linux-kernel@...r.kernel.org>
Subject: Re: PATCH] Use -mpreferred-stack-boundary=3 on x86-64 if supported

To keep gcc from paddong the stack to maintain a nonexistent alignment.

Andi Kleen <andi@...stfloor.org> wrote:

>> This patch uses -mpreferred-stack-boundary=3 on x86-64 if it is
>supported.
>> I have been running 3.4 kernel compiled with this option for weeks.
>
>But why? 
>
>All the SSE code in the kernel should adjust manually. And the other
>code doesn't need it.
>
>Besides the entry points do not guarantee alignment.
>
>For the kernel it would be probably more useful to have a attribute
>per function that forces alignment.
>
>-Andi
>-- 
>ak@...ux.intel.com -- Speaking for myself only.

-- 
Sent from my mobile phone. Please excuse brevity and lack of formatting.
--
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/