Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this. Avoid the bug by generating the
UUID into a local variable which is definitely safely aligned and
then copying it into place.
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
block/vpc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/block/vpc.c b/block/vpc.c
index 80c5b2b197e..968d80ae461 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -979,6 +979,7 @@ static int coroutine_fn vpc_co_create(BlockdevCreateOptions
*opts,
int64_t total_size;
int disk_type;
int ret = -EIO;
+ QemuUUID uuid;
assert(opts->driver == BLOCKDEV_DRIVER_VPC);
vpc_opts = &opts->u.vpc;
@@ -1062,7 +1063,8 @@ static int coroutine_fn
vpc_co_create(BlockdevCreateOptions *opts,
footer->type = cpu_to_be32(disk_type);
- qemu_uuid_generate(&footer->uuid);
+ qemu_uuid_generate(&uuid);
+ footer->uuid = uuid;
footer->checksum = cpu_to_be32(vpc_checksum(buf, HEADER_SIZE));
--
2.19.2
