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To: linux-kernel@vger.kernel.org
From: "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: sysenter on x86
Date: 14 Apr 2003 11:14:57 -0700
Organization: Transmeta Corporation, Santa Clara CA
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References: <20030412135457.GB19869@codeblau.de> <1050156926.1449.2.camel@laptop.fenrus.com>
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Followup to:  <1050156926.1449.2.camel@laptop.fenrus.com>
By author:    Arjan van de Ven <arjanv@redhat.com>
In newsgroup: linux.dev.kernel
>
> 
> --=-EFK+Hzuvs0Z6BUNjBVGk
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> On Sat, 2003-04-12 at 15:54, Felix von Leitner wrote:
> > I just added sysenter support for linux-2.5 on x86 to the diet libc, but
> > I noted that the original patch said user space should jump to
> > 0xfffff000, which segfaults.  Jumping to 0xffffe000 works.
> >=20
> > I suggest adding a comment somewhere in the kernel about the proper
> > calling convention, because the glibc code is frankly not readable in
> > this regard.
> 
> you HAVE to use the location as specified with the AT_SYSINFO elf flag.
> The kernel is free to move this address around between builds, as long
> as AT_SYSINFO gives the address for the location.
> 

... which quite frankly kind of bites :(

	-hpa
-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
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