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

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@iscas.ac.cn>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260119061232.889236-1-nichen@iscas.ac.cn

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
index 7748b6641a3c304a3e28a17e038662887a7fce3c..e8163fdee69a1fd7581a9b7d150486d6ad3040e7 100644 (file)
--- 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