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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2013-06-12 23:05:08 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-06-13 01:29:46 +0200 |
| commit | 7b57976da48e60b66fdbb9e97f5711b5382a49d7 (patch) | |
| tree | 4295f72436564c0bbb0521cbf486fd6907aa5e18 /mm/swapfile.c | |
| parent | kernel/audit_tree.c:audit_add_tree_rule(): protect `rule' from kill_rules() (diff) | |
| download | linux-7b57976da48e60b66fdbb9e97f5711b5382a49d7.tar.xz linux-7b57976da48e60b66fdbb9e97f5711b5382a49d7.zip | |
frontswap: fix incorrect zeroing and allocation size for frontswap_map
The bitmap accessed by bitops must have enough size to hold the required
numbers of bits rounded up to a multiple of BITS_PER_LONG. And the
bitmap must not be zeroed by memset() if the number of bits cleared is
not a multiple of BITS_PER_LONG.
This fixes incorrect zeroing and allocation size for frontswap_map. The
incorrect zeroing part doesn't cause any problem because frontswap_map
is freed just after zeroing. But the wrongly calculated allocation size
may cause the problem.
For 32bit systems, the allocation size of frontswap_map is about twice
as large as required size. For 64bit systems, the allocation size is
smaller than requeired if the number of bits is not a multiple of
BITS_PER_LONG.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/swapfile.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 6c340d908b27..746af55b8455 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2116,7 +2116,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) } /* frontswap enabled? set up bit-per-page map for frontswap */ if (frontswap_enabled) - frontswap_map = vzalloc(maxpages / sizeof(long)); + frontswap_map = vzalloc(BITS_TO_LONGS(maxpages) * sizeof(long)); if (p->bdev) { if (blk_queue_nonrot(bdev_get_queue(p->bdev))) { |