Re: [PATCH 1/1] arm: devtree: fix missing device_node cleanup

[Javier Carrasco <javier.carrasco.cruz@gmail.com>]

On 12/07/2024 11:44, Vincenzo Mezzela wrote:
> Device node `cpus` is allocated but never released using `of_node_put`.
> 
> This patch introduces the __free attribute for `cpus` device_node that
> automatically handle the cleanup of the resource by adding a call to
> `of_node_put` at the end of the current scope. This enhancement aims to
> mitigate memory management issues associated with forgetting to release
> the resources.
> 
> Signed-off-by: Vincenzo Mezzela <vincenzo.mezzela@gmail.com>
> ---
>  arch/arm/kernel/devtree.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
> index fdb74e64206a..223d66a5fff3 100644
> --- a/arch/arm/kernel/devtree.c
> +++ b/arch/arm/kernel/devtree.c
> @@ -70,14 +70,14 @@ void __init arm_dt_init_cpu_maps(void)
>  	 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
>  	 * read as 0.
>  	 */
> -	struct device_node *cpu, *cpus;
>  	int found_method = 0;
>  	u32 i, j, cpuidx = 1;
>  	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
>  
>  	u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
>  	bool bootcpu_valid = false;
> -	cpus = of_find_node_by_path("/cpus");
> +	struct device_node *cpu;
> +	struct device_node *cpus __free(device_node) = of_find_node_by_path("/cpus");
>  
>  	if (!cpus)
>  		return;

Hello Vincenzo,

If this is a fix, please provide the Fixes: tag as well as Cc: for
stable if it applies.

Best regards,
Javier Carrasco