From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Bastian Blank <waldi@debian.org>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Ian Campbell <Ian.Campbell@citrix.com>,
"544145@bugs.debian.org" <544145@bugs.debian.org>
Subject: Re: Bug#544145: Crash with paravirt-ops 2.6.31.6 kernel
Date: Mon, 23 Nov 2009 16:52:26 -0800 [thread overview]
Message-ID: <4B0B2E4A.7020805@goop.org> (raw)
In-Reply-To: <20091123172334.GA25056@wavehammer.waldi.eu.org>
On 11/23/09 09:23, Bastian Blank wrote:
>> I don't believe that is the case (the processor would have to carry some
>> state for the entire duration of a syscall for it to make any
>> difference). I think the spec simply assumes that an OS author would
>> want to use sysret if they used syscall.
>>
> Well, it is documented this way. If you ignore it, it can work (and does
> in this case) but is undefined behaviour.
>
Linux freely uses iret to return from syscall for things like fork and
exec. They are complimentary instructions, but nothing requires them to
be paired.
J
next prev parent reply other threads:[~2009-11-24 0:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-17 19:04 Crash with paravirt-ops 2.6.31.6 kernel William Pitcock
2009-11-18 14:45 ` Konrad Rzeszutek Wilk
2009-11-19 8:21 ` William Pitcock
2009-11-19 17:31 ` Konrad Rzeszutek Wilk
2009-11-20 4:12 ` Jeremy Fitzhardinge
2009-11-22 9:54 ` Bastian Blank
2009-11-23 15:25 ` Ian Campbell
2009-11-23 16:31 ` Bug#544145: [Xen-devel] " Bastian Blank
2009-11-23 16:42 ` Bug#544145: " Ian Campbell
2009-11-23 17:23 ` Bug#544145: [Xen-devel] " Bastian Blank
2009-11-24 0:52 ` Jeremy Fitzhardinge [this message]
2009-11-23 16:31 ` Jan Beulich
2009-11-23 16:44 ` Ian Campbell
2009-11-23 17:13 ` Keir Fraser
2009-11-23 17:17 ` Ian Campbell
2009-11-25 10:22 ` Jan Beulich
2009-11-25 21:24 ` Jeremy Fitzhardinge
2009-11-26 7:35 ` Jan Beulich
2009-11-26 9:57 ` Ian Campbell
2009-11-24 0:39 ` Jeremy Fitzhardinge
2009-11-24 9:48 ` Ian Campbell
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