cache aliasing in dup_mmap

[Steven Walter]

On Thu, Nov 5, 2009 at 9:48 AM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
>> I've not heard anything further.  I've thrown the patches into the git
>> tree under a separate branch now (top two):
>>
>> http://ftp.arm.linux.org.uk/git/gitweb.cgi?p=linux-2.6-arm.git;a=shortlog;h=refs/heads/cup
>>
>> I do feel that more work needs to be done to the 2nd patch though.
>
> Okay, enough.  This issue is NOT going to get fixed unless you (or
> someone else who can reproduce your problem) responds.
>
> No response, no fix.  Simple, really.  I give you two weeks to respond
> on this issue so it can be progressed before the above branch is trashed.
>

I apologize for the late reply.  I have a build with your patches
running in a reboot loop (the easiest way for us to reproduce the
crash).  I should have a good indication of whether the patches fix
the issue by Monday.

Just by examining the changes, your patches seem to be a superset of
the change I made locally, which did fix the issue.  My fix was simply
to add flush_cache_page before cow_user_page in mm/memory.c.
-- 
-Steven Walter <stevenrwalter at gmail.com>