linux-kernel - Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock

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: <4C3E11BD.2090503@zytor.com>
Date:	Wed, 14 Jul 2010 12:36:29 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	"H.J. Lu" <hjl.tools@...il.com>
CC:	Jeremy Fitzhardinge <jeremy@...p.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Peter Palfrader <peter@...frader.org>,
	Avi Kivity <avi@...hat.com>, Greg KH <gregkh@...e.de>,
	linux-kernel@...r.kernel.org, stable@...nel.org,
	stable-review@...nel.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Glauber Costa <glommer@...hat.com>,
	Zachary Amsden <zamsden@...hat.com>,
	Marcelo Tosatti <mtosatti@...hat.com>
Subject: Re: [patch 134/149] x86, paravirt: Add a global synchronization point
 	for pvclock

On 07/14/2010 12:32 PM, H.J. Lu wrote:
> On Wed, Jul 14, 2010 at 12:00 PM, H. Peter Anvin <hpa@...or.com> wrote:
>> On 07/14/2010 11:18 AM, H.J. Lu wrote:
>>>
>>> There are some discussions on:
>>>
>>> http://gcc.gnu.org/ml/gcc-patches/2010-06/msg02001.html
>>> http://gcc.gnu.org/ml/gcc-patches/2010-07/msg00001.html
>>>
>>> Are they related?
>>>
>>
>> Not directly as far as I can tell.
>>
>> The issue is if gcc can ever reorder, duplicate or elide a volatile
>> operation (either asm volatile or a volatile-annotated memory
>> reference.)  In my (and Linus') opinion, this would be an incredibly
>> serious bug.
> 
> Is there a gcc bug for this?
> 

Are you asking for a bug report against the documentation?  We're not
sure what the semantics intended by the gcc team to be, which I guess is
a documentation bug.

	-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/