| 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
| ||
|
Date: Thu, 19 Nov 2009 16:49:57 +0100 From: Richard Guenther <richard.guenther@...il.com> To: "H. Peter Anvin" <hpa@...or.com> Cc: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>, Andrew Morton <akpm@...ux-foundation.org>, Heiko Carstens <heiko.carstens@...ibm.com>, feng.tang@...el.com, "Fr??d??ric Weisbecker" <fweisbec@...il.com>, Steven Rostedt <rostedt@...dmis.org>, Peter Zijlstra <peterz@...radead.org>, jakub@...hat.com, gcc@....gnu.org Subject: Re: BUG: GCC-4.4.x changes the function frame on some functions On Thu, Nov 19, 2009 at 4:45 PM, H. Peter Anvin <hpa@...or.com> wrote: > On 11/19/2009 07:37 AM, Thomas Gleixner wrote: >> >> modified function start on a handful of functions only seen with gcc >> 4.4.x on x86 32 bit: >> >> push %edi >> lea 0x8(%esp),%edi >> and $0xfffffff0,%esp >> pushl -0x4(%edi) >> push %ebp >> mov %esp,%ebp >> ... >> call mcount >> > > The real questions is why we're aligning the stack in the kernel. It is > probably not what we want -- we don't use SSE for anything but a handful > of special cases in the kernel, and we don't want the overhead. It's likely because you have long long vars on the stack which is faster when they are aligned. -mno-stackrealign may do what you want (or may not, I have not checked). I assume you already use -mpreferred-stack-boundary=2. Richard. -- 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/
Powered by blists - more mailing lists