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

Andy Lutomirski
2014-03-12T21:49:29Z

On Wed, Mar 12, 2014 at 2:46 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Wed, Mar 12, 2014 at 2:37 PM, H. Peter Anvin <hpa@linux.intel.com> wrote:
>>
>> How would that deal with the legacy vsyscall case for x86-64? Just rely
>> on the "legacy vsyscall emulation" (which seems to have its own class of
>> problems...)?
>
> It does?
>
> We *default* to emulation, and have for over two years now (since
> v3.4). If there are problems with it, we need to fix those.

Even in the non-default "vsyscall=native" case, the vsyscall pages
just contains syscalls. It does not need to access the vvar page, the
hpet, or anything else that the vdso uses.

>
> Linus

--
Andy Lutomirski
AMA Capital Management, LLC