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Date:   Wed, 7 Apr 2021 18:19:44 +0200
From:   Alexandre Belloni <alexandre.belloni@bootlin.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc:     Nicolas Ferre <nicolas.ferre@microchip.com>,
        Ludovic Desroches <ludovic.desroches@microchip.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] memory: atmel-sdramc: check of_device_get_match_data()
 return value
Message-ID: <YG3boJNqAoNCBeIB@piout.net>
References: <20210407154447.70540-1-krzysztof.kozlowski@canonical.com>
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In-Reply-To: <20210407154447.70540-1-krzysztof.kozlowski@canonical.com>
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Hi,

On 07/04/2021 17:44:47+0200, Krzysztof Kozlowski wrote:
> If the driver is probed, the of_device_get_match_data() should not
> return NULL, however for sanity check its return value.
> 

As you say, there is no way this will ever be the case, I don't see the
point of checking the return value, this adds 12 bytes for nothing...

Maybe coverity should be fixed as there are many drivers making the same
(true) assumption and I don't think this is worth the churn.

> Addresses-Coverity: Dereference null return value
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> ---
>  drivers/memory/atmel-sdramc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/memory/atmel-sdramc.c b/drivers/memory/atmel-sdramc.c
> index 9c49d00c2a96..e09b2617f63d 100644
> --- a/drivers/memory/atmel-sdramc.c
> +++ b/drivers/memory/atmel-sdramc.c
> @@ -45,6 +45,8 @@ static int atmel_ramc_probe(struct platform_device *pdev)
>  	struct clk *clk;
>  
>  	caps = of_device_get_match_data(&pdev->dev);
> +	if (!caps)
> +		return -EINVAL;
>  
>  	if (caps->has_ddrck) {
>  		clk = devm_clk_get(&pdev->dev, "ddrck");
> -- 
> 2.25.1
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com