diff options
| author | Andrea Arcangeli <aarcange@redhat.com> | 2011-03-18 00:16:35 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-17 16:31:13 -0700 |
| commit | ef2b4b95a63a1d23958dcb99eb2c6898eddc87d0 (patch) | |
| tree | 0a22745dba03926768552aa3006b166995e5342d /mm/page_alloc.c | |
| parent | 7b7adc4a016a1decb806eb71ecab98721fa7f146 (diff) | |
| download | lwn-ef2b4b95a63a1d23958dcb99eb2c6898eddc87d0.tar.gz lwn-ef2b4b95a63a1d23958dcb99eb2c6898eddc87d0.zip | |
mm: PageBuddy and mapcount robustness
Change the _mapcount value indicating PageBuddy from -2 to -128 for
more robusteness against page_mapcount() undeflows.
Use reset_page_mapcount instead of __ClearPageBuddy in bad_page to
ignore the previous retval of PageBuddy().
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index bd7625676a64..7945247b1e53 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -286,7 +286,7 @@ static void bad_page(struct page *page) /* Don't complain about poisoned pages */ if (PageHWPoison(page)) { - __ClearPageBuddy(page); + reset_page_mapcount(page); /* remove PageBuddy */ return; } @@ -317,7 +317,7 @@ static void bad_page(struct page *page) dump_stack(); out: /* Leave bad fields for debug, except PageBuddy could make trouble */ - __ClearPageBuddy(page); + reset_page_mapcount(page); /* remove PageBuddy */ add_taint(TAINT_BAD_PAGE); } |