* [PATCH] memory: atmel-sdramc: check of_device_get_match_data() return value
@ 2021-04-07 15:44 Krzysztof Kozlowski
2021-04-07 16:19 ` Alexandre Belloni
0 siblings, 1 reply; 3+ messages in thread
From: Krzysztof Kozlowski @ 2021-04-07 15:44 UTC (permalink / raw)
To: Krzysztof Kozlowski, Nicolas Ferre, Alexandre Belloni,
Ludovic Desroches, linux-kernel, linux-arm-kernel
If the driver is probed, the of_device_get_match_data() should not
return NULL, however for sanity check its return value.
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] memory: atmel-sdramc: check of_device_get_match_data() return value
2021-04-07 15:44 [PATCH] memory: atmel-sdramc: check of_device_get_match_data() return value Krzysztof Kozlowski
@ 2021-04-07 16:19 ` Alexandre Belloni
2021-04-07 16:55 ` Krzysztof Kozlowski
0 siblings, 1 reply; 3+ messages in thread
From: Alexandre Belloni @ 2021-04-07 16:19 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Nicolas Ferre, Ludovic Desroches, linux-kernel, linux-arm-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] memory: atmel-sdramc: check of_device_get_match_data() return value
2021-04-07 16:19 ` Alexandre Belloni
@ 2021-04-07 16:55 ` Krzysztof Kozlowski
0 siblings, 0 replies; 3+ messages in thread
From: Krzysztof Kozlowski @ 2021-04-07 16:55 UTC (permalink / raw)
To: Alexandre Belloni
Cc: Nicolas Ferre, Ludovic Desroches, linux-kernel, linux-arm-kernel
On 07/04/2021 18:19, Alexandre Belloni wrote:
> 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.
There are also several drivers having this check. To me an explicit NULL
check is better and more readable than non-obvious assumption that the
of_device_id table contains data for each entry and there is no other
bind method (like for OF+I2C drivers). Even if the case is not real,
this is nice, simple and explicit code.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-04-07 15:44 [PATCH] memory: atmel-sdramc: check of_device_get_match_data() return value Krzysztof Kozlowski
2021-04-07 16:19 ` Alexandre Belloni
2021-04-07 16:55 ` Krzysztof Kozlowski
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