Re: [PATCH 1/9] staging: media: atomisp: fix incorrect NULL pointer check

From: Nick Desaulniers <ndesaulniers@google.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	linux-media@vger.kernel.org, devel@driverdev.osuosl.org,
	LKML <linux-kernel@vger.kernel.org>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Nathan Chancellor <natechancellor@gmail.com>
Subject: Re: [PATCH 1/9] staging: media: atomisp: fix incorrect NULL pointer check
Date: Fri, 29 May 2020 13:04:05 -0700	[thread overview]
Message-ID: <CAKwvOdnND7XFgr7W9PvZAikJB1nKxB4K5N-oP0YrBT74oX_C9g@mail.gmail.com> (raw)
In-Reply-To: <20200529200031.4117841-1-arnd@arndb.de>

See also Nathan's 7 patch series.
https://lore.kernel.org/lkml/20200527071150.3381228-1-natechancellor@gmail.com/

Might be some overlap between series?

On Fri, May 29, 2020 at 1:00 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> Checking the pointer to a member of a struct against NULL
> is pointless as clang points out:
>
> drivers/staging/media/atomisp/pci/atomisp_cmd.c:4278:17: error: address of 'config->info' will always evaluate to 'true'
>
> Check the original pointer instead, which may also be
> unnecessary here, but makes a little more sense.
>
> Fixes: 9d4fa1a16b28 ("media: atomisp: cleanup directory hierarchy")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/staging/media/atomisp/pci/atomisp_cmd.c | 2 +-
>  drivers/staging/media/atomisp/pci/sh_css.c      | 4 ++--
>  drivers/staging/media/atomisp/pci/sh_css_sp.c   | 4 ++--
>  3 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/staging/media/atomisp/pci/atomisp_cmd.c b/drivers/staging/media/atomisp/pci/atomisp_cmd.c
> index 5be690f876c1..342fc3b34fe0 100644
> --- a/drivers/staging/media/atomisp/pci/atomisp_cmd.c
> +++ b/drivers/staging/media/atomisp/pci/atomisp_cmd.c
> @@ -4275,7 +4275,7 @@ int atomisp_param(struct atomisp_sub_device *asd, int flag,
>                     atomisp_css_get_dvs_grid_info(
>                         &asd->params.curr_grid_info);
>
> -               if (!&config->info) {
> +               if (!config) {
>                         dev_err(isp->dev, "ERROR: NULL pointer in grid_info\n");
>                         return -EINVAL;
>                 }
> diff --git a/drivers/staging/media/atomisp/pci/sh_css.c b/drivers/staging/media/atomisp/pci/sh_css.c
> index d77432254a2c..e91c6029c651 100644
> --- a/drivers/staging/media/atomisp/pci/sh_css.c
> +++ b/drivers/staging/media/atomisp/pci/sh_css.c
> @@ -8534,7 +8534,7 @@ ia_css_pipe_load_extension(struct ia_css_pipe *pipe,
>
>         if (firmware->info.isp.type == IA_CSS_ACC_OUTPUT)
>         {
> -               if (&pipe->output_stage)
> +               if (pipe)
>                         append_firmware(&pipe->output_stage, firmware);
>                 else {
>                         IA_CSS_LEAVE_ERR_PRIVATE(IA_CSS_ERR_INTERNAL_ERROR);
> @@ -8542,7 +8542,7 @@ ia_css_pipe_load_extension(struct ia_css_pipe *pipe,
>                 }
>         } else if (firmware->info.isp.type == IA_CSS_ACC_VIEWFINDER)
>         {
> -               if (&pipe->vf_stage)
> +               if (pipe)
>                         append_firmware(&pipe->vf_stage, firmware);
>                 else {
>                         IA_CSS_LEAVE_ERR_PRIVATE(IA_CSS_ERR_INTERNAL_ERROR);
> diff --git a/drivers/staging/media/atomisp/pci/sh_css_sp.c b/drivers/staging/media/atomisp/pci/sh_css_sp.c
> index e574396ad0f4..c0e579c1705f 100644
> --- a/drivers/staging/media/atomisp/pci/sh_css_sp.c
> +++ b/drivers/staging/media/atomisp/pci/sh_css_sp.c
> @@ -1022,7 +1022,7 @@ sh_css_sp_init_stage(struct ia_css_binary *binary,
>                 if (!pipe)
>                         return IA_CSS_ERR_INTERNAL_ERROR;
>                 ia_css_get_crop_offsets(pipe, &args->in_frame->info);
> -       } else if (&binary->in_frame_info)
> +       } else if (binary)
>         {
>                 pipe = find_pipe_by_num(sh_css_sp_group.pipe[thread_id].pipe_num);
>                 if (!pipe)
> @@ -1036,7 +1036,7 @@ sh_css_sp_init_stage(struct ia_css_binary *binary,
>                         if (!pipe)
>                                 return IA_CSS_ERR_INTERNAL_ERROR;
>                         ia_css_get_crop_offsets(pipe, &args->in_frame->info);
> -               } else if (&binary->in_frame_info) {
> +               } else if (binary) {
>                         pipe = find_pipe_by_num(sh_css_sp_group.pipe[thread_id].pipe_num);
>                         if (!pipe)
>                                 return IA_CSS_ERR_INTERNAL_ERROR;
> --
> 2.26.2
>
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-- 
Thanks,
~Nick Desaulniers