The following commit has been merged in the linux branch: commit 92f7ba70eecf4da8264a767b181cc2090f62d4ad Author: Hugh Dickins hugh.dickins@tiscali.co.uk Date: Mon Oct 26 16:49:31 2009 -0700
hwpoison: fix oops on ksm pages
Memory failure on a KSM page currently oopses on its NULL anon_vma in page_lock_anon_vma(): that may not be much worse than the consequence of ignoring it, but it is better to be consistent with how ZERO_PAGE and hugetlb pages and other awkward cases are treated. Just skip it.
We could fix it for 2.6.32 at the KSM end, by putting a dummy anon_vma pointer in there; but that would get harder next time, when KSM will put a pointer to something else there (and I'm not currently planning to do any work to open that up to memory_failure). So I would prefer this simple PageKsm test, until the other exceptions are handled.
Signed-off-by: Hugh Dickins hugh.dickins@tiscali.co.uk Cc: Andi Kleen andi@firstfloor.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 729d4b1..7fc2130 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -35,6 +35,7 @@ #include <linux/mm.h> #include <linux/page-flags.h> #include <linux/sched.h> +#include <linux/ksm.h> #include <linux/rmap.h> #include <linux/pagemap.h> #include <linux/swap.h> @@ -661,7 +662,7 @@ static void hwpoison_user_mappings(struct page *p, unsigned long pfn, int i; int kill = 1;
- if (PageReserved(p) || PageCompound(p) || PageSlab(p)) + if (PageReserved(p) || PageCompound(p) || PageSlab(p) || PageKsm(p)) return;
if (!PageLRU(p))