[CRIU] [PATCH 2/3] mem: if no parent image persists, can't rely on it

[Cyrill Gorcunov]

On Tue, Apr 15, 2014 at 11:15:19PM +0400, Cyrill Gorcunov wrote:
> On Tue, Apr 15, 2014 at 11:07:28PM +0400, Pavel Tikhomirov wrote:
> >    Please read this comment.
> >    Best Regards, Tikhomirov Pavel.
> > 
> >    2014-04-15 17:43 GMT+04:00 Pavel Tikhomirov <snorcht at gmail.com>:
> > 
> >      Ok, but what if parent writes to memory first and gets COW'ed,
> >      and child gets writable memory when access it.
> >      It can result in no PF.
> >      Just an Idea, need to understand COW mechanism more precisely.
> 
> OK, as far as I remember, once the process is forked, its pte/pmd structures
> become allocated but not present, once child attempt to read something, the

Sorry, for COW there is copy_one_pte which would WP both parent and child.