Re: sysenter on x86

From: H. Peter Anvin (hpa@zytor.com)
Date: Mon Apr 14 2003 - 13:14:57 EST


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
> Content-Type: text/plain
> Content-Transfer-Encoding: quoted-printable
>
> 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."
Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Tue Apr 15 2003 - 22:00:32 EST