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[Qemu-devel] [PATCH 07/30] block: fix allocation size for dirty bitmap
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 07/30] block: fix allocation size for dirty bitmap |
Date: |
Thu, 10 May 2012 13:49:11 +0200 |
From: Paolo Bonzini <address@hidden>
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 <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/block.c b/block.c
index 754a422..3db84cd 100644
--- a/block.c
+++ b/block.c
@@ -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) {
--
1.7.6.5
- [Qemu-devel] [PULL 00/30] Block patches for 1.1, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 01/30] block: add the support to drain throttled requests, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 03/30] block: fail live snapshot if disk has no medium, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 04/30] block: push bdrv_change_backing_file error checking up from drivers, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 10/30] qtest: Add floppy test, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 06/30] block: open backing file as read-only when probing for size, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 09/30] qtest: Add function to send QMP commands, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 12/30] block: another bdrv_append fix, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 07/30] block: fix allocation size for dirty bitmap,
Kevin Wolf <=
- [Qemu-devel] [PATCH 02/30] block: add mode argument to blockdev-snapshot-sync, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 05/30] block: update in-memory backing file and format, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 14/30] block: fully delete bs->file when closing, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 17/30] block: simplify path_is_absolute, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 08/30] qemu-iotests: strip spaces from qemu-img/qemu-io/qemu command lines, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 13/30] block: do not reuse the backing file across bdrv_close/bdrv_open, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 20/30] qemu-img: make "info" backing file output correct and easier to use, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 18/30] block: protect path_has_protocol from filenames with colons, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 11/30] block: fix snapshot on QED, Kevin Wolf, 2012/05/10
- [Qemu-devel] [PATCH 15/30] block: add block_job_sleep_ns, Kevin Wolf, 2012/05/10