ShuriZma
/
xqemu
mirror of https://github.com/xqemu/xqemu.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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>
This commit is contained in:
Paolo Bonzini 2012-04-12 14:01:04 +02:00 committed by Kevin Wolf
parent 63090dac3a
commit 71df14fcbe
1 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
block.c
View File

@ -1584,6 +1584,8 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false); 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, static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int dirty) 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; end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
for (; start <= end; start++) { for (; start <= end; start++) {
idx = start / (sizeof(unsigned long) * 8); idx = start / BITS_PER_LONG;
bit = start % (sizeof(unsigned long) * 8); bit = start % BITS_PER_LONG;
val = bs->dirty_bitmap[idx]; val = bs->dirty_bitmap[idx];
if (dirty) { if (dirty) {
if (!(val & (1UL << bit))) { if (!(val & (1UL << bit))) {
@ -3900,10 +3902,10 @@ void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
if (enable) { if (enable) {
if (!bs->dirty_bitmap) { if (!bs->dirty_bitmap) {
bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) + bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1; BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG - 1;
bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8; 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 { } else {
if (bs->dirty_bitmap) { if (bs->dirty_bitmap) {