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| author | Nick Piggin <npiggin@suse.de> | 2006-09-25 23:31:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 08:48:48 -0700 |
| commit | 28e4d965e6131ace1e813e93aebca89ac6b82dc1 (patch) | |
| tree | 6c98aa227c5cfdc9fb51ddf53c4497127beb3ca1 | |
| parent | bfa5bf6d6446f0028187a727f792fbc7934228ad (diff) | |
| download | lwn-28e4d965e6131ace1e813e93aebca89ac6b82dc1.tar.gz lwn-28e4d965e6131ace1e813e93aebca89ac6b82dc1.zip | |
[PATCH] mm: remove_mapping() safeness
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.
[hugh@veritas.com: swapper_space fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | mm/vmscan.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 41a3da3d6ccc..16180587fd7d 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -377,8 +377,8 @@ static pageout_t pageout(struct page *page, struct address_space *mapping) 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(page)); write_lock_irq(&mapping->tree_lock); @@ -547,7 +547,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, goto free_it; } - if (!remove_mapping(mapping, page)) + if (!mapping || !remove_mapping(mapping, page)) goto keep_locked; free_it: |