block-backend: Silence clang -m32 compiler warning

[PATCH] block-backend: Silence clang -m32 compiler warning

Hanna Reitz posted 1 patch 2 years, 6 months ago

Download mbox

Test checkpatch passed

Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20211026090745.30800-1-hreitz@redhat.com

Maintainers: Hanna Reitz <hreitz@redhat.com>, Kevin Wolf <kwolf@redhat.com>

block/block-backend.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Expand all Fold all

[PATCH] block-backend: Silence clang -m32 compiler warning

Posted by Hanna Reitz 2 years, 6 months ago

Similarly to e7e588d432d31ecebc26358e47201dd108db964c, there is a
warning in block/block-backend.c that qiov->size <= INT64_MAX is always
true on machines where size_t is narrower than a uint64_t.  In said
commit, we silenced this warning by casting to uint64_t.

The commit introducing this warning here
(a93d81c84afa717b0a1a6947524d8d1fbfd6bbf5) anticipated it and so tried
to address it the same way.  However, it only did so in one of two
places where this comparison occurs, and so we still need to fix up the
other one.

Fixes: a93d81c84afa717b0a1a6947524d8d1fbfd6bbf5
       ("block-backend: convert blk_aio_ functions to int64_t bytes
       paramter")
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
---
 block/block-backend.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 39cd99df2b..12ef80ea17 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1540,7 +1540,7 @@ BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
                             QEMUIOVector *qiov, BdrvRequestFlags flags,
                             BlockCompletionFunc *cb, void *opaque)
 {
-    assert(qiov->size <= INT64_MAX);
+    assert((uint64_t)qiov->size <= INT64_MAX);
     return blk_aio_prwv(blk, offset, qiov->size, qiov,
                         blk_aio_write_entry, flags, cb, opaque);
 }
-- 
2.31.1

Re: [PATCH] block-backend: Silence clang -m32 compiler warning

Posted by Philippe Mathieu-Daudé 2 years, 6 months ago

On 10/26/21 11:07, Hanna Reitz wrote:
> Similarly to e7e588d432d31ecebc26358e47201dd108db964c, there is a
> warning in block/block-backend.c that qiov->size <= INT64_MAX is always
> true on machines where size_t is narrower than a uint64_t.  In said
> commit, we silenced this warning by casting to uint64_t.
> 
> The commit introducing this warning here
> (a93d81c84afa717b0a1a6947524d8d1fbfd6bbf5) anticipated it and so tried
> to address it the same way.  However, it only did so in one of two
> places where this comparison occurs, and so we still need to fix up the
> other one.
> 
> Fixes: a93d81c84afa717b0a1a6947524d8d1fbfd6bbf5
>        ("block-backend: convert blk_aio_ functions to int64_t bytes
>        paramter")
> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
> ---
>  block/block-backend.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>