Re: [PATCH 15/18] x86 vDSO: consolidate vdso32

From: Ingo Molnar
Date: Tue Nov 20 2007 - 19:13:53 EST



* Zachary Amsden <zach@xxxxxxxxxx> wrote:

> > The 32-bit vDSO mapping now behaves the same on x86_64 as on native
> > 32-bit. The abi.syscall32 sysctl on x86_64 now takes the same values
> > that vm.vdso_enabled takes on the 32-bit kernel. That is, 1 means a
> > randomized vDSO location, 2 means the fixed old address. The
> > CONFIG_COMPAT_VDSO option is now available to make this the default
> > setting, the same meaning it has for the 32-bit kernel. (This does
> > not affect the 64-bit vDSO.)
>
> I think you should drop CONFIG_COMPAT_VDSO support for 32-bit VDSO on
> 64-bit kernel. This was only to hack around a broken version of glibc
> that shipped with SUSE PRO 9.0, which had broken assertions based on
> misinterpretation of ELF fields. 64-bit machines will never see this
> glibc and the hack can die.
>
> Perhaps it is finally time to remove the hack from 32-bit as well, and
> eliminate COMPAT_VDSO entirely? Or does it really have to live
> forever.

we can phase it out, via the Documentation/feature-removal-schedule.txt
mechanism.

Ingo
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