[v1] -Werror=maybe-uninitialized fixes

[PATCH 05/19] block/mirror: fix -Werror=maybe-uninitialized false-positive

marcandre.lureau@redhat.com posted 19 patches 1 year, 10 months ago

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Maintainers: John Snow <jsnow@redhat.com>, Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, Keith Busch <kbusch@kernel.org>, Klaus Jensen <its@irrelevant.dk>, Jesper Devantier <foss@defmacro.it>, Yuval Shaia <yuval.shaia.ml@gmail.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Fam Zheng <fam@euphon.net>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Bin Meng <bin.meng@windriver.com>, "Eugenio Pérez" <eperezma@redhat.com>, Peter Xu <peterx@redhat.com>, Fabiano Rosas <farosas@suse.de>, Hyman Huang <yong.huang@smartx.com>, Eric Blake <eblake@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>, Alexandre Iooss <erdnaxe@crans.org>, Mahmoud Mandour <ma.mandourr@gmail.com>, Pierrick Bouvier <pierrick.bouvier@linaro.org>

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[PATCH 05/19] block/mirror: fix -Werror=maybe-uninitialized false-positive

Posted by marcandre.lureau@redhat.com 1 year, 10 months ago

From: Marc-André Lureau <marcandre.lureau@redhat.com>

../block/mirror.c:1066:22: error: ‘iostatus’ may be used uninitialized [-Werror=maybe-uninitialized]

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 block/mirror.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/mirror.c b/block/mirror.c
index 1bdce3b657..53dd7332ee 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -926,7 +926,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
     MirrorBDSOpaque *mirror_top_opaque = s->mirror_top_bs->opaque;
     BlockDriverState *target_bs = blk_bs(s->target);
     bool need_drain = true;
-    BlockDeviceIoStatus iostatus;
+    BlockDeviceIoStatus iostatus = BLOCK_DEVICE_IO_STATUS__MAX;
     int64_t length;
     int64_t target_length;
     BlockDriverInfo bdi;
-- 
2.44.0

Re: [PATCH 05/19] block/mirror: fix -Werror=maybe-uninitialized false-positive

Posted by Vladimir Sementsov-Ogievskiy 1 year, 10 months ago

On 28.03.24 13:20, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> ../block/mirror.c:1066:22: error: ‘iostatus’ may be used uninitialized [-Werror=maybe-uninitialized]

Actually that's a false-positive.. Compiler can't believe that body of WITH_JOB_LOCK_GUARD() will be executed unconditionally. Probably we should mention this in a comment.

> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

> ---
>   block/mirror.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/block/mirror.c b/block/mirror.c
> index 1bdce3b657..53dd7332ee 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -926,7 +926,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
>       MirrorBDSOpaque *mirror_top_opaque = s->mirror_top_bs->opaque;
>       BlockDriverState *target_bs = blk_bs(s->target);
>       bool need_drain = true;
> -    BlockDeviceIoStatus iostatus;
> +    BlockDeviceIoStatus iostatus = BLOCK_DEVICE_IO_STATUS__MAX;
>       int64_t length;
>       int64_t target_length;
>       BlockDriverInfo bdi;

-- 
Best regards,
Vladimir