lkml.org 
[lkml]   [2009]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] [8/16] POISON: Add various poison checks in mm/memory.c
    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()?


    \
     
     \ /
      Last update: 2009-04-07 21:07    [W:0.020 / U:61.564 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site