Re: [PATCH] coresight: trbe: Fix incorrect error check for devm_kzalloc

[Jie Gan <jie.gan@oss.qualcomm.com>]

On 8/29/2025 8:08 PM, Miaoqian Lin wrote:
> Fix incorrect use of IS_ERR() to check devm_kzalloc() return value.
> devm_kzalloc() returns NULL on failure, not an error pointer.
> 
> This issue was introduced by commit 4277f035d227
> ("coresight: trbe: Add a representative coresight_platform_data for TRBE")
> which replaced the original function but didn't update the error check.
> 
> Fixes: 4277f035d227 ("coresight: trbe: Add a representative coresight_platform_data for TRBE")
> Cc: stable@vger.kernel.org
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>   drivers/hwtracing/coresight/coresight-trbe.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
> index 8267dd1a2130..caf873adfc3a 100644
> --- a/drivers/hwtracing/coresight/coresight-trbe.c
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -1279,7 +1279,7 @@ static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cp
>   	 * into the device for that purpose.
>   	 */
>   	desc.pdata = devm_kzalloc(dev, sizeof(*desc.pdata), GFP_KERNEL);
> -	if (IS_ERR(desc.pdata))

IS_ERR_OR_NULL(desc.pdata) would be better.

Thanks,
Jie

> +	if (!desc.pdata)
>   		goto cpu_clear;
>   
>   	desc.type = CORESIGHT_DEV_TYPE_SINK;