diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2012-04-12 14:01:04 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2012-05-10 10:32:11 +0200 |
| commit | 71df14fcbe5035d0728f30463414301eb62ad865 (patch) | |
| tree | 173287c2a889188b8fb106e24212ea93c9e28b7b /block.c | |
| parent | 63090dac3a7c5fe02b4285cf2e5fb7017d2c7b0e (diff) | |
block: fix allocation size for dirty bitmap
Also reuse elsewhere the new constant for sizeof(unsigned long) * 8.
The dirty bitmap is allocated in bits but declared as unsigned long.
Thus, its memory block is accessed beyond its end unless the image
is a multiple of 64 chunks (i.e. a multiple of 64 MB).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 12 |
1 files changed, 7 insertions, 5 deletions
@@ -1584,6 +1584,8 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num, return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false); } +#define BITS_PER_LONG (sizeof(unsigned long) * 8) + static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int dirty) { @@ -1594,8 +1596,8 @@ static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num, end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK; for (; start <= end; start++) { - idx = start / (sizeof(unsigned long) * 8); - bit = start % (sizeof(unsigned long) * 8); + idx = start / BITS_PER_LONG; + bit = start % BITS_PER_LONG; val = bs->dirty_bitmap[idx]; if (dirty) { if (!(val & (1UL << bit))) { @@ -3900,10 +3902,10 @@ void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable) if (enable) { if (!bs->dirty_bitmap) { bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) + - BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1; - bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8; + BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG - 1; + bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG; - bs->dirty_bitmap = g_malloc0(bitmap_size); + bs->dirty_bitmap = g_new0(unsigned long, bitmap_size); } } else { if (bs->dirty_bitmap) { |