[PATCH] remoteproc: st: Fix sometimes uninitialized ret in st_rproc_probe()

[Nick Desaulniers]

On Thu, Oct 12, 2023 at 10:04 AM Nathan Chancellor <nathan at kernel.org> wrote:
>
> Clang warns (or errors with CONFIG_WERROR=y):
>
>   drivers/remoteproc/st_remoteproc.c:357:6: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
>     357 |         if (!ddata->config)
>         |             ^~~~~~~~~~~~~~
>   drivers/remoteproc/st_remoteproc.c:442:9: note: uninitialized use occurs here
>     442 |         return ret;
>         |                ^~~
>   drivers/remoteproc/st_remoteproc.c:357:2: note: remove the 'if' if its condition is always false
>     357 |         if (!ddata->config)
>         |         ^~~~~~~~~~~~~~~~~~~
>     358 |                 goto free_rproc;
>         |                 ~~~~~~~~~~~~~~~
>   drivers/remoteproc/st_remoteproc.c:348:9: note: initialize the variable 'ret' to silence this warning
>     348 |         int ret, i;
>         |                ^
>         |                 = 0
>   1 error generated.
>
> Set ret to -ENODEV, which seems to be a standard return code when
> device_get_match_data() returns NULL.
>
> Closes: https://github.com/ClangBuiltLinux/linux/issues/1944
> Fixes: 5c77ebcd05ac ("remoteproc: st: Use device_get_match_data()")
> Signed-off-by: Nathan Chancellor <nathan at kernel.org>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers at google.com>

> ---
>  drivers/remoteproc/st_remoteproc.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/st_remoteproc.c b/drivers/remoteproc/st_remoteproc.c
> index b0638f984842..cb163766c56d 100644
> --- a/drivers/remoteproc/st_remoteproc.c
> +++ b/drivers/remoteproc/st_remoteproc.c
> @@ -354,8 +354,10 @@ static int st_rproc_probe(struct platform_device *pdev)
>         rproc->has_iommu = false;
>         ddata = rproc->priv;
>         ddata->config = (struct st_rproc_config *)device_get_match_data(dev);
> -       if (!ddata->config)
> +       if (!ddata->config) {
> +               ret = -ENODEV;
>                 goto free_rproc;
> +       }
>
>         platform_set_drvdata(pdev, rproc);
>
>
> ---
> base-commit: 5c77ebcd05acf3789949c8a387df72381d949ca2
> change-id: 20231012-st_remoteproc-fix-sometimes-uninit-7aff1bdb7349
>
> Best regards,
> --
> Nathan Chancellor <nathan at kernel.org>
>


-- 
Thanks,
~Nick Desaulniers