Re: [PATCH] kselftests: dmabuf-heaps: Ensure the driver name is null-terminated

[T.J. Mercier]

On Mon, Jul 8, 2024 at 6:47 AM Zenghui Yu <yuzenghui@xxxxxxxxxx> wrote:
>
> Even if a vgem device is configured in, we will skip the import_vgem_fd()
> test almost every time.
>
>   TAP version 13
>   1..11
>   # Testing heap: system
>   # =======================================
>   # Testing allocation and importing:
>   ok 1 # SKIP Could not open vgem -1
>
> The problem is that we use the DRM_IOCTL_VERSION ioctl to query the driver
> version information but leave the name field a non-null-terminated string.
> Terminate it properly to actually test against the vgem device.

Hm yeah. Looks like drm_copy_field resets version.name to the actual
size of the name in the case of truncation, so maybe worth checking
that too in case there is a name like "vgemfoo" that gets converted to
"vgem\0" by this?

>
> Signed-off-by: Zenghui Yu <yuzenghui@xxxxxxxxxx>
> ---
>  tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> index 5f541522364f..2fcc74998fa9 100644
> --- a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> +++ b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> @@ -32,6 +32,8 @@ static int check_vgem(int fd)
>         if (ret)
>                 return 0;
>
> +       name[4] = '\0';
> +
>         return !strcmp(name, "vgem");
>  }
>
> --
> 2.33.0
>