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

Andy Lutomirski
2014-05-15T22:15:54Z

On Thu, May 15, 2014 at 2:57 PM, Cyrill Gorcunov <gorcunov@gmail.com> wrote:
> On Thu, May 15, 2014 at 02:42:48PM -0700, Andy Lutomirski wrote:
>> >
>> > 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.
>>
>> Please don't!
>>
>> These might, in principle, even vary between tasks on the same system.
>> Certainly the relative positions of the vmas will be different
>> between 3.15 and 3.16, since we need almost my entire cleanup series
>> to reliably put them into their 3.16 location. And I intend to change
>> the number of pages in 3.16 or 3.17.
>
> There are other ways how to find where additional pages are laying but it
> would be great if there a straightforward interface for that (ie some mark
> in /proc/pid/maps output).

I'll try to write a patch in time for 3.15.

--Andy