[PATCH] block: Remove unnecessary NULL check in bdrv_pad_request()

Kevin Wolf posted 1 patch 1 month ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20240327192750.204197-1-kwolf@redhat.com
Maintainers: Stefan Hajnoczi <stefanha@redhat.com>, Fam Zheng <fam@euphon.net>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>
block/io.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] block: Remove unnecessary NULL check in bdrv_pad_request()
Posted by Kevin Wolf 1 month ago
Coverity complains that the check introduced in commit 3f934817 suggests
that qiov could be NULL and we dereference it before reaching the check.
In fact, all of the callers pass a non-NULL pointer, so just remove the
misleading check.

Resolves: Coverity CID 1542668
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/io.c b/block/io.c
index 395bea3bac..7217cf811b 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1730,7 +1730,7 @@ static int bdrv_pad_request(BlockDriverState *bs,
      * For prefetching in stream_populate(), no qiov is passed along, because
      * only copy-on-read matters.
      */
-    if (qiov && *qiov) {
+    if (*qiov) {
         sliced_iov = qemu_iovec_slice(*qiov, *qiov_offset, *bytes,
                                       &sliced_head, &sliced_tail,
                                       &sliced_niov);
-- 
2.44.0
Re: [PATCH] block: Remove unnecessary NULL check in bdrv_pad_request()
Posted by Philippe Mathieu-Daudé 4 weeks, 1 day ago
On 27/3/24 20:27, Kevin Wolf wrote:
> Coverity complains that the check introduced in commit 3f934817 suggests
> that qiov could be NULL and we dereference it before reaching the check.
> In fact, all of the callers pass a non-NULL pointer, so just remove the
> misleading check.
> 
> Resolves: Coverity CID 1542668
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   block/io.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Since I'm not seeing other block related patch for 9.0 and
I'm preparing a pull request, I'm queuing this one.

Regards,

Phil.
Re: [PATCH] block: Remove unnecessary NULL check in bdrv_pad_request()
Posted by Kevin Wolf 4 weeks ago
Am 02.04.2024 um 12:53 hat Philippe Mathieu-Daudé geschrieben:
> On 27/3/24 20:27, Kevin Wolf wrote:
> > Coverity complains that the check introduced in commit 3f934817 suggests
> > that qiov could be NULL and we dereference it before reaching the check.
> > In fact, all of the callers pass a non-NULL pointer, so just remove the
> > misleading check.
> > 
> > Resolves: Coverity CID 1542668
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> >   block/io.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Since I'm not seeing other block related patch for 9.0 and
> I'm preparing a pull request, I'm queuing this one.

Thanks, Phil. I didn't send a pull request because I didn't have
anything else and silencing a Coverity false positive didn't seem urgent
for 9.0, but it certainly doesn't hurt either.

Kevin
Re: [PATCH] block: Remove unnecessary NULL check in bdrv_pad_request()
Posted by Philippe Mathieu-Daudé 1 month ago
On 27/3/24 20:27, Kevin Wolf wrote:
> Coverity complains that the check introduced in commit 3f934817 suggests
> that qiov could be NULL and we dereference it before reaching the check.
> In fact, all of the callers pass a non-NULL pointer, so just remove the
> misleading check.
> 
> Resolves: Coverity CID 1542668
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   block/io.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>



Re: [PATCH] block: Remove unnecessary NULL check in bdrv_pad_request()
Posted by Fiona Ebner 1 month ago
Am 27.03.24 um 20:27 schrieb Kevin Wolf:
> Coverity complains that the check introduced in commit 3f934817 suggests
> that qiov could be NULL and we dereference it before reaching the check.
> In fact, all of the callers pass a non-NULL pointer, so just remove the
> misleading check.
> 
> Resolves: Coverity CID 1542668
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Reviewed-by: Fiona Ebner <f.ebner@proxmox.com>

Thank you for the fix,
Fiona