Re: [patch] mm: recheck lock rlim after f_op->mmap() method

[Dmitry Monakhov <dmonakhov@sw.ru>]

On 18:27 Втр 10 Июл     , Hugh Dickins wrote:
> On Mon, 9 Jul 2007, Dmitry Monakhov wrote:
> > Some device drivers can change vm_flags in their f_op->mmap
> > method. In order to be on the safe side we have to recheck
> > lock rlimit. Now we have to check lock rlimit from two places,
> > let's move this common code to helper functon.
> > 
> > Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
> > ---
> >  mm/mmap.c |   33 ++++++++++++++++++++++++++-------
> >  1 files changed, 26 insertions(+), 7 deletions(-)
> 
> Or would this simpler patch be the right one?  I suspect the
> mspec driver only says VM_LOCKED because of a deep-seated but
> irrational fear that its pages might fall into reclaim.
No mspec is not the only one :( , in my case it was fglrx (ati driver).
BTW: where is comment about it in do_mmap_pgoff:  
	/* Can addr have changed??
	 *
	 * Answer: Yes, several device drivers can do
	 * it in their
	 *         f_op->mmap method. -DaveM
	 */
	addr = vma->vm_start;
	pgoff = vma->vm_pgoff;
	vm_flags = vma->vm_flags;
> 
> (I'd like to take out VM_RESERVED too, but that can always happen
> another, indefinitely postponed time; there are others of those.)
> 
> Hugh
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