[PATCH] powerpc/52xx/media5200: Consolidate chained IRQ handler install/remove

Subsystems: linux for powerpc (32-bit and 64-bit), linux for powerpc embedded mpc5xxx, the rest

STALE116d

2 messages, 2 authors, 2026-04-08 · open the first message on its own page

[PATCH] powerpc/52xx/media5200: Consolidate chained IRQ handler install/remove

From: Chen Ni <hidden>
Date: 2026-01-19 06:06:00

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 <redacted>
---
 arch/powerpc/platforms/52xx/media5200.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/52xx/media5200.c b/arch/powerpc/platforms/52xx/media5200.c
index bc7f83cfec1d..c20ac8010f6d 100644
--- a/arch/powerpc/platforms/52xx/media5200.c
+++ b/arch/powerpc/platforms/52xx/media5200.c
@@ -176,8 +176,8 @@ static void __init media5200_init_irq(void)
 
 	of_node_put(fpga_np);
 
-	irq_set_handler_data(cascade_virq, &media5200_irq);
-	irq_set_chained_handler(cascade_virq, media5200_irq_cascade);
+	irq_set_chained_handler_and_data(cascade_virq, media5200_irq_cascade,
+					 &media5200_irq);
 
 	return;
 
-- 
2.25.1

Re: [PATCH] powerpc/52xx/media5200: Consolidate chained IRQ handler install/remove

From: Madhavan Srinivasan <maddy@linux.ibm.com>
Date: 2026-04-08 04:29:12

On Mon, 19 Jan 2026 14:04:50 +0800, Chen Ni wrote:
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.

[...]
Applied to powerpc/next.

[1/1] powerpc/52xx/media5200: Consolidate chained IRQ handler install/remove
      https://git.kernel.org/powerpc/c/1ef8cf10cdbe79823fd6de0f0b93ca996045d1cc

cheers
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