Re: [PATCH v2] x86: Remove compat vdso support

H. Peter Anvin
2014-03-11T16:54:11Z

On 03/11/2014 09:50 AM, Andy Lutomirski wrote:
> Looking forward, would it be reasonable to have an extensible set of
> flags that live in the ELF interpreter's headers somewhere that
> indicate compatibility hacks that the program in question doesn't
> need? There are at least two things I can think of:
>
> - no_compat_vdso32: indicates an interpreter that can load a modern
> non-prelinked vdso
> - no_vsyscall64: indicates that the libc will not attempt to call
> into the vsyscall page on x86_64.
>
> I'm sure that there are more. Think PT_GNU_STACK but for more than
> just the stack.
>
> If we do something like this, there should probably be a prctl or
> similar that can change some of the flags at runtime, too.
>

This comes many years too late for this purpose. Such flags might have
a use, but at this point it is rather meaningless, I think.

-hpa