linux-kernel - Re: [PATCH v3 2/2] x86_64: Don't save flags on context switch

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]

Message-ID: <542C496F.80003@zytor.com>
Date:	Wed, 01 Oct 2014 11:35:27 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Andy Lutomirski <luto@...capital.net>,
	Thomas Gleixner <tglx@...utronix.de>, X86 ML <x86@...nel.org>,
	Ingo Molnar <mingo@...hat.com>
CC:	Sebastian Lackner <sebastian@...-team.de>,
	Anish Bhatt <anish@...lsio.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Chuck Ebbert <cebbert.lkml@...il.com>
Subject: Re: [PATCH v3 2/2] x86_64: Don't save flags on context switch

On 10/01/2014 11:28 AM, Andy Lutomirski wrote:
>  
>  #define __EXTRA_CLOBBER  \
>  	, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
> -	  "r12", "r13", "r14", "r15"
> +	  "r12", "r13", "r14", "r15", "flags"
>  

I was under the impression that gcc *always* assumes the flags were
clobbered for an asm statement.  Otherwise I think we'd have a lot of
problems.

	-hpa


--
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/