Messages in this thread | | | Date | Tue, 7 Apr 2009 21:03:30 +0200 | From | Johannes Weiner <> | Subject | Re: [PATCH] [8/16] POISON: Add various poison checks in mm/memory.c |
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On Tue, Apr 07, 2009 at 05:10:05PM +0200, Andi Kleen wrote: > > Bail out early when poisoned pages are found in page fault handling. > Since they are poisoned they should not be mapped freshly > into processes. > > This is generally handled in the same way as OOM, just a different > error code is returned to the architecture code. > > Signed-off-by: Andi Kleen <ak@linux.intel.com> > > --- > mm/memory.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > Index: linux/mm/memory.c > =================================================================== > --- linux.orig/mm/memory.c 2009-04-07 16:39:39.000000000 +0200 > +++ linux/mm/memory.c 2009-04-07 16:39:39.000000000 +0200 > @@ -2560,6 +2560,10 @@ > goto oom; > __SetPageUptodate(page); > > + /* Kludge for now until we take poisoned pages out of the free lists */ > + if (unlikely(PagePoison(page))) > + return VM_FAULT_POISON; > +
When memory_failure() hits a page still on the free list (!page_count()) then the get_page() in memory_failure() will trigger a VM_BUG. So either this check is unneeded or it should be get_page_unless_zero() in memory_failure()?
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