The patch titled
mm: remove_mapping() safeness
has been added to the -mm tree. Its filename is
mm-remove_mapping-safeness.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: mm: remove_mapping() safeness
From: Nick Piggin <npiggin@xxxxxxx>
Some users of remove_mapping had been unsafe.
Modify the remove_mapping precondition to ensure the caller has locked the
page and obtained the correct mapping. Modify callers to ensure the
mapping is the correct one.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/vmscan.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff -puN mm/vmscan.c~mm-remove_mapping-safeness mm/vmscan.c
--- a/mm/vmscan.c~mm-remove_mapping-safeness
+++ a/mm/vmscan.c
@@ -377,8 +377,8 @@ static pageout_t pageout(struct page *pa
int remove_mapping(struct address_space *mapping, struct page *page)
{
- if (!mapping)
- return 0; /* truncate got there first */
+ BUG_ON(!PageLocked(page));
+ BUG_ON(mapping != page->mapping);
write_lock_irq(&mapping->tree_lock);
@@ -547,7 +547,7 @@ static unsigned long shrink_page_list(st
goto free_it;
}
- if (!remove_mapping(mapping, page))
+ if (!mapping || !remove_mapping(mapping, page))
goto keep_locked;
free_it:
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
mm-vm_bug_on.patch
radix-tree-rcu-lockless-readside.patch
redo-radix-tree-fixes.patch
adix-tree-rcu-lockless-readside-update.patch
adix-tree-rcu-lockless-readside-fix-2.patch
update-some-mm-comments.patch
mm-remove_mapping-safeness.patch
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