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

[Brian Gerst]

On Wed, Mar 12, 2014 at 12:04 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Mar 12, 2014 at 8:46 AM, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> But I think that "x86, vdso: Add 32 bit VDSO time support for 32 bit
>> kernel" patch needs to die. And the helper patches building up to it
>> (just because that patch used [io_]remap_pfn_range()) should die too.
>> Why weren't those pages in the vdso*_pages[] array anyway?
>
> Sorry, confused. FIXMAP, not vdso_pages.
>
> Anyway, that's what x86-64 does. Why not 32?

A 32-bit process running on a 64-bit kernel cannot access the high
fixmap mappings.  The VVAR/HPET pages have to be mapped below 4GB.

--
Brian Gerst
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