3.13.11.4 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: Naoya Horiguchi <[email protected]>

commit 3e030ecc0fc7de10fd0da10c1c19939872a31717 upstream.

When a memory error happens on an in-use page or (free and in-use)
hugepage, the victim page is isolated with its refcount set to one.

When you try to unpoison it later, unpoison_memory() calls put_page()
for it twice in order to bring the page back to free page pool (buddy or
free hugepage list).  However, if another memory error occurs on the
page which we are unpoisoning, memory_failure() returns without
releasing the refcount which was incremented in the same call at first,
which results in memory leak and unconsistent num_poisoned_pages
statistics.  This patch fixes it.

Signed-off-by: Naoya Horiguchi <[email protected]>
Cc: Andi Kleen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
---
 mm/memory-failure.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index b22effc..3b0855b 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1157,6 +1157,8 @@ int memory_failure(unsigned long pfn, int trapno, int 
flags)
         */
        if (!PageHWPoison(p)) {
                printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
+               atomic_long_sub(nr_pages, &num_poisoned_pages);
+               put_page(hpage);
                res = 0;
                goto out;
        }
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to