[PATCH] powerpc/52xx/mpc52xx_gpt: consolidate chained IRQ handler install/remove

[Chen Ni]

The driver currently sets the handler data and the chained handler in
two separate steps. This creates a theoretical race window where an
interrupt could fire after the handler is set but before the data is
assigned, leading to a NULL pointer dereference.

Replace the two calls with irq_set_chained_handler_and_data() to set
both the handler and its data atomically under the irq_desc->lock.

Signed-off-by: Chen Ni <nichen at iscas.ac.cn>
---
 arch/powerpc/platforms/52xx/mpc52xx_gpt.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
index 7748b6641a3c..e8163fdee69a 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
@@ -253,8 +253,7 @@ mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
 		return;
 	}
 
-	irq_set_handler_data(cascade_virq, gpt);
-	irq_set_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
+	irq_set_chained_handler_and_data(cascade_virq, mpc52xx_gpt_irq_cascade, gpt);
 
 	/* If the GPT is currently disabled, then change it to be in Input
 	 * Capture mode.  If the mode is non-zero, then the pin could be
-- 
2.25.1