[PATCH] vdpa/mlx5: fix error handling in mlx5_vdpa_dev_add()

From: trix
Date: Fri Jan 07 2022 - 16:14:04 EST


From: Tom Rix <trix@xxxxxxxxxx>

Clang build fails with
mlx5_vnet.c:2574:6: error: variable 'mvdev' is used uninitialized whenever
'if' condition is true
if (!ndev->vqs || !ndev->event_cbs) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mlx5_vnet.c:2660:14: note: uninitialized use occurs here
put_device(&mvdev->vdev.dev);
^~~~~
This because mvdev is set after trying to allocate ndev->vqs,event_cbs.
So move the allocation to after mvdev is set but before the arrays
are used in init_mvqs()

Fixes: 7620d51af29a ("vdpa/mlx5: Support configuring max data virtqueue")
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index b564c70475815..37220f6db7ad7 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -2569,16 +2569,18 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
if (IS_ERR(ndev))
return PTR_ERR(ndev);

+ ndev->mvdev.mlx_features = mgtdev->mgtdev.supported_features;
+ ndev->mvdev.max_vqs = max_vqs;
+ mvdev = &ndev->mvdev;
+ mvdev->mdev = mdev;
+
ndev->vqs = kcalloc(max_vqs, sizeof(*ndev->vqs), GFP_KERNEL);
ndev->event_cbs = kcalloc(max_vqs + 1, sizeof(*ndev->event_cbs), GFP_KERNEL);
if (!ndev->vqs || !ndev->event_cbs) {
err = -ENOMEM;
goto err_alloc;
}
- ndev->mvdev.mlx_features = mgtdev->mgtdev.supported_features;
- ndev->mvdev.max_vqs = max_vqs;
- mvdev = &ndev->mvdev;
- mvdev->mdev = mdev;
+
init_mvqs(ndev);
mutex_init(&ndev->reslock);
config = &ndev->config;
--
2.26.3