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References: <20230303102751.9374-1-jason-ch.chen@mediatek.com>
In-Reply-To: <20230303102751.9374-1-jason-ch.chen@mediatek.com>
From:   Mathieu Poirier <mathieu.poirier@linaro.org>
Date:   Fri, 3 Mar 2023 11:20:15 -0700
Message-ID: <CANLsYky0pbqiEfq7E6DZM=J+sm2JJ8gYST2atUyP8X7y9zdHWA@mail.gmail.com>
Subject: Re: [PATCH] remoteproc: mediatek: Dereferencing a pointer that might
 be NULL
To:     Jason-ch Chen <jason-ch.chen@mediatek.com>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Project_Global_Chrome_Upstream_Group@mediatek.com,
        linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        linux-remoteproc@vger.kernel.org
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On Fri, 3 Mar 2023 at 03:28, Jason-ch Chen <jason-ch.chen@mediatek.com> wrote:
>
> From: jason-ch chen <Jason-ch.Chen@mediatek.com>
>
> The res might be NULL when calling resource_size.
>

"resource_size" ?  What is that?

> Signed-off-by: jason-ch chen <Jason-ch.Chen@mediatek.com>
> ---
>  drivers/remoteproc/mtk_scp.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> index eacdf241f4ef..863d18f63f58 100644
> --- a/drivers/remoteproc/mtk_scp.c
> +++ b/drivers/remoteproc/mtk_scp.c
> @@ -829,6 +829,9 @@ static int scp_probe(struct platform_device *pdev)
>         platform_set_drvdata(pdev, scp);
>
>         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sram");
> +       if (!res)
> +               return -ENODEV;
> +

Please have a look at the implementation of devm_ioremap_resource()
along with the function it calls and let me know if your patch is
needed.

>         scp->sram_base = devm_ioremap_resource(dev, res);
>         if (IS_ERR((__force void *)scp->sram_base)) {
>                 dev_err(dev, "Failed to parse and map sram memory\n");
> --
> 2.37.3
>