Re: [PATCH] sample: vfio mdev display - Fix a missing error code in an error handling path

[Alex Williamson]

On Mon, 16 Sep 2019 22:22:40 +0200
Christophe JAILLET <christophe.jail...@wanadoo.fr> wrote:

> 'ret' is known to be 0 at this point. So explicitly set it to -ENOMEM if
> 'framebuffer_alloc()' fails.
> 
> Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
> ---
>  samples/vfio-mdev/mdpy-fb.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
> index 2719bb259653..6fe0187f47a2 100644
> --- a/samples/vfio-mdev/mdpy-fb.c
> +++ b/samples/vfio-mdev/mdpy-fb.c
> @@ -131,8 +131,10 @@ static int mdpy_fb_probe(struct pci_dev *pdev,
>                width, height);
>  
>       info = framebuffer_alloc(sizeof(struct mdpy_fb_par), &pdev->dev);
> -     if (!info)
> +     if (!info) {
> +             ret = -ENOMEM;
>               goto err_release_regions;
> +     }
>       pci_set_drvdata(pdev, info);
>       par = info->par;
>  

I think you're only scratching the surface here, this looks more
complete to me:

diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c
index 2719bb259653..a760e130bd0d 100644
--- a/samples/vfio-mdev/mdpy-fb.c
+++ b/samples/vfio-mdev/mdpy-fb.c
@@ -117,22 +117,27 @@ static int mdpy_fb_probe(struct pci_dev *pdev,
        if (format != DRM_FORMAT_XRGB8888) {
                pci_err(pdev, "format mismatch (0x%x != 0x%x)\n",
                        format, DRM_FORMAT_XRGB8888);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto err_release_regions;
        }
        if (width < 100  || width > 10000) {
                pci_err(pdev, "width (%d) out of range\n", width);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto err_release_regions;
        }
        if (height < 100 || height > 10000) {
                pci_err(pdev, "height (%d) out of range\n", height);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto err_release_regions;
        }
        pci_info(pdev, "mdpy found: %dx%d framebuffer\n",
                 width, height);
 
        info = framebuffer_alloc(sizeof(struct mdpy_fb_par), &pdev->dev);
-       if (!info)
+       if (!info) {
+               ret = -ENOMEM;
                goto err_release_regions;
+       }
        pci_set_drvdata(pdev, info);
        par = info->par;