block/vdi.c: Make SECTOR_SIZE constant 64-bits
Make the VDI SECTOR_SIZE define be a 64-bit constant; this matches
how we define BDRV_SECTOR_SIZE. The benefit is that it means that we
don't need to carefully cast to 64-bits when doing operations like
"n_sectors * SECTOR_SIZE" to avoid doing a 32x32->32 multiply, which
might overflow, and which Coverity and other static analysers tend to
warn about.
The specific potential overflow Coverity is highlighting is the one
at the end of vdi_co_pwritev() where we write out n_sectors sectors
to the block map. This is very unlikely to actually overflow, since
the block map has 4 bytes per block and the maximum number of blocks
in the image must fit into a 32-bit integer. So this commit is not
fixing a real-world bug.
An inspection of all the places currently using SECTOR_SIZE in the
file shows none which care about the change in its type, except for
one call to error_setg() which needs the format string adjusting.
Resolves: Coverity CID 1508076
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20241008164708.2966400-5-peter.maydell@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/vdi.c b/block/vdi.c
index 149e15c..26f7638 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -87,7 +87,7 @@
/* Command line option for static images. */
#define BLOCK_OPT_STATIC "static"
-#define SECTOR_SIZE 512
+#define SECTOR_SIZE 512ULL
#define DEFAULT_CLUSTER_SIZE 1048576
/* Note: can't use 1 * MiB, because it's passed to stringify() */
@@ -442,7 +442,7 @@
goto fail;
} else if (header.sector_size != SECTOR_SIZE) {
error_setg(errp, "unsupported VDI image (sector size %" PRIu32
- " is not %u)", header.sector_size, SECTOR_SIZE);
+ " is not %llu)", header.sector_size, SECTOR_SIZE);
ret = -ENOTSUP;
goto fail;
} else if (header.block_size != DEFAULT_CLUSTER_SIZE) {
