Re: [PATCH] coresight: cti: Add const to con_groups allocation type

[Mike Leach <mike.leach@arm.com>]

Reviewed-by: Mike Leach <mike.leach@arm.com>


On 9/17/26 22:14, Kees Cook wrote:
> From: Kees Cook <kees+treewide@kernel.org>
> 
> In preparation for making the devm_kmalloc family of allocators type
> aware, we need to make sure that the returned type from the allocation
> matches the type of the variable being assigned. (Before, the allocator
> would always return "void *", which can be implicitly cast to any
> pointer type.)
> 
> The assigned type is "const struct attribute_group **", but the
> converted allocation type would be "struct attribute_group **", which is
> the same type without the const qualifier. As there is no general way to
> safely add const qualifiers, take the size from the assignment target
> instead. No change in allocation size results.
> 
> Build tested ARCH=arm64 allmodconfig with GCC aarch64-linux-gnu 16.1.0:
> drivers/hwtracing/coresight/coresight-cti-sysfs.o
> 
> Assisted-by: LLM coccinelle
> Signed-off-by: Kees Cook <kees+treewide@kernel.org>
> ---
> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> Cc: Mike Leach <mike.leach@arm.com>
> Cc: James Clark <james.clark@linaro.org>
> Cc: Leo Yan <leo.yan@arm.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: <coresight@lists.linaro.org>
> Cc: <linux-arm-kernel@lists.infradead.org>
> ---
>   drivers/hwtracing/coresight/coresight-cti-sysfs.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> index 3fe2c916d228..2ed5d8eb1dda 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> @@ -1132,7 +1132,7 @@ static int cti_create_cons_groups(struct device *dev, struct cti_device *ctidev)
>   	/* nr groups = dynamic + static + NULL terminator */
>   	nr_groups = ctidev->nr_trig_con + CORESIGHT_CTI_STATIC_GROUPS_MAX;
>   	ctidev->con_groups = devm_kcalloc(dev, nr_groups,
> -					  sizeof(struct attribute_group *),
> +					  sizeof(*ctidev->con_groups),
>   					  GFP_KERNEL);
>   	if (!ctidev->con_groups)
>   		return -ENOMEM;