[Xen-devel] [PATCH 9 of 13] Remove the read hazard from the COW path in copy_one_pte

[Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>]

1 file changed, 1 insertion(+), 1 deletion(-)
mm/memory.c |    2 +-


We don't want to read PTEs directly like this after they have been
modified, as a lazy MMU implementation of direct page tables may not
have written the updated PTE back to memory yet.

Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>



===================================================================

diff -r 0adfc39039c7 -r 20f9c0c451af mm/memory.c
--- a/mm/memory.c       Tue Aug 01 01:32:00 2006 -0700
+++ b/mm/memory.c       Tue Aug 01 01:32:00 2006 -0700
@@ -466,7 +466,7 @@ copy_one_pte(struct mm_struct *dst_mm, s
         */
        if (is_cow_mapping(vm_flags)) {
                ptep_set_wrprotect(src_mm, addr, src_pte);
-               pte = *src_pte;
+               pte = pte_wrprotect(pte);
        }
 
        /*



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