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From: Chen Ni <nichen@iscas.ac.cn>
To: agust@denx.de, maddy@linux.ibm.com, mpe@ellerman.id.au,
	npiggin@gmail.com, chleroy@kernel.org, tglx@kernel.org,
	brgl@kernel.org, jirislaby@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	Chen Ni <nichen@iscas.ac.cn>
Subject: [PATCH] powerpc/52xx/mpc52xx_gpt: consolidate chained IRQ handler install/remove
Date: Mon, 19 Jan 2026 14:12:32 +0800	[thread overview]
Message-ID: <20260119061232.889236-1-nichen@iscas.ac.cn> (raw)

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>
---
 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



             reply	other threads:[~2026-01-19  6:13 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-19  6:12 Chen Ni [this message]
2026-01-19  9:41 ` [PATCH] powerpc/52xx/mpc52xx_gpt: consolidate chained IRQ handler install/remove Bartosz Golaszewski
2026-04-08  4:28 ` Madhavan Srinivasan

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