[PATCH v3] irqchip/gic-v3-its: Fix OF node reference leak

[Yuho Choi]

of_get_cpu_node() returns a referenced device node. In
its_cpu_init_collection(), the Cavium 23144 workaround only uses the
node to compare the CPU NUMA node, but the reference is never dropped.

Use the device_node cleanup helper for the CPU node reference so it is
released when leaving the workaround block, including the NUMA mismatch
return path.

Fixes: fbf8f40e1658 ("irqchip/gicv3-its: numa: Enable workaround for Cavium thunderx erratum 23144")
Signed-off-by: Yuho Choi <dbgh9129 at gmail.com>
Acked-by: Marc Zyngier <maz at kernel.org>
---
Changes in v3:
- Keep the __free(device_node) assignment on a single line.
- Fix indentation in the Cavium 23144 workaround block.
- Add Marc's Acked-by.
Changes in v2:
- Use __free(device_node) for the CPU node reference.
- Correct the Fixes tag to fbf8f40e1658.
 drivers/irqchip/irq-gic-v3-its.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index b57d81ad33a0..6f5811aae59c 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3290,11 +3290,9 @@ static void its_cpu_init_collection(struct its_node *its)
 
 	/* avoid cross node collections and its mapping */
 	if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
-		struct device_node *cpu_node;
+		struct device_node *cpu_node __free(device_node) = of_get_cpu_node(cpu, NULL);
 
-		cpu_node = of_get_cpu_node(cpu, NULL);
-		if (its->numa_node != NUMA_NO_NODE &&
-			its->numa_node != of_node_to_nid(cpu_node))
+		if (its->numa_node != NUMA_NO_NODE && its->numa_node != of_node_to_nid(cpu_node))
 			return;
 	}
 
-- 
2.43.0