Re: mm: NULL ptr deref handling mmaping of special mappings

Cyrill Gorcunov
2014-05-15T21:31:28Z

On Fri, May 16, 2014 at 12:19:14AM +0400, Cyrill Gorcunov wrote:
>
> I see what you mean. We're rather targeting on bare x86-64 at the moment
> but compat mode is needed as well (not yet implemented though). I'll take
> a precise look into this area. Thanks!

Indeed, because we were not running 32bit tasks vdso32-setup.c::arch_setup_additional_pages
has never been called. That's the mode we will have to implement one day.

Looking forward the question appear -- will VDSO_PREV_PAGES and rest of variables
be kind of immutable constants? If yes, we could calculate where the additional
vma lives without requiring any kind of [vdso] mark in proc/pid/maps output.