cpuidle: riscv-sbi: fix device node release in early exit of for_each_possible_cpu

[ Upstream commit 7e25044b804581b9c029d5a28d8800aebde18043 ]

The 'np' device_node is initialized via of_cpu_device_node_get(), which
requires explicit calls to of_node_put() when it is no longer required
to avoid leaking the resource.

Instead of adding the missing calls to of_node_put() in all execution
paths, use the cleanup attribute for 'np' by means of the __free()
macro, which automatically calls of_node_put() when the variable goes
out of scope. Given that 'np' is only used within the
for_each_possible_cpu(), reduce its scope to release the nood after
every iteration of the loop.

Fixes: 6abf32f1d9c5 ("cpuidle: Add RISC-V SBI CPU idle driver")
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20241116-cpuidle-riscv-sbi-cleanup-v3-1-a3a46372ce08@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c
index af7320a768d27f5677eec6720a380804eb8595e9..963d5f171ef7c34f2a723dd9e8291cf755d64f6f 100644 (file)
--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -540,12 +540,12 @@ static int sbi_cpuidle_probe(struct platform_device *pdev)
        int cpu, ret;
        struct cpuidle_driver *drv;
        struct cpuidle_device *dev;
-       struct device_node *np, *pds_node;
+       struct device_node *pds_node;
 
        /* Detect OSI support based on CPU DT nodes */
        sbi_cpuidle_use_osi = true;
        for_each_possible_cpu(cpu) {
-               np = of_cpu_device_node_get(cpu);
+               struct device_node *np __free(device_node) = of_cpu_device_node_get(cpu);
                if (np &&
                    of_find_property(np, "power-domains", NULL) &&
                    of_find_property(np, "power-domain-names", NULL)) {