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

[Ingo Molnar <mingo@elte.hu>]

* Zachary Amsden <zach@vmware.com> 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