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Re: turn off VDSO on glibc side
- From: "Carlos O'Donell" <carlos at redhat dot com>
- To: Mike Frysinger <vapier at gentoo dot org>
- Cc: libc-help at sourceware dot org
- Date: Wed, 03 Jul 2013 13:29:10 -0400
- Subject: Re: turn off VDSO on glibc side
- References: <87fvvymich dot fsf at proton dot in dot awa dot tohoku dot ac dot jp> <201307011258 dot 55684 dot vapier at gentoo dot org> <87bo6jlgwx dot fsf at proton dot in dot awa dot tohoku dot ac dot jp> <201307031318 dot 36364 dot vapier at gentoo dot org>
On 07/03/2013 01:18 PM, Mike Frysinger wrote:
> On Wednesday 03 July 2013 12:58:06 heroxbd wrote:
>> Mike Frysinger writes:
>>> there aren't any configure flags or runtime knobs that i know of on
>>> the glibc side of things. you could edit elf/dl-support.c and try
>>> commenting out the parts that handle AT_SYSINFO and AT_SYSINFO_EHDR.
>>
>> I've pursued this approach. So far a base system was built around the
>> patched glibc on that vdso-buggy kernel, verifying that it works. Here I
>> attach a simple (and ugly) patch I used to disable VDSO completely for
>> completeness.
>
> i'm not sure there's a way to generalize this, and i don't think this is a
> patch i want to carry in Gentoo's glibc build. i don't have a good answer
> short of "upgrade your kernel". sucks either way.
A runtime tunable might get you part of the way but it would
be disabled for AT_SECURE. Would that help?
I'll add this to the list of things users want to control.
Cheers,
Carlos.