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

From: Vincenzo Mezzela
Date: Fri Jul 12 2024 - 05:45:25 EST


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@xxxxxxxxx>
---
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;
--
2.43.0