[PATCH] genirq: Avoid NULL OOPS in irq handling

From: Huacai Chen
Date: Fri Sep 27 2013 - 22:12:03 EST


Some devices (e.g. serial port) setup irq handler at dev open and free
it at dev close. So, sometimes there is no irqaction for a specific
irq. But some buggy devices may send irqs at any time. This patch avoid
the NULL OOPS when irqaction isn't registered.

Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
---
kernel/irq/handle.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 131ca17..1c78e69 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -135,6 +135,9 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
irqreturn_t retval = IRQ_NONE;
unsigned int flags = 0, irq = desc->irq_data.irq;

+ if (!action)
+ goto out;
+
do {
irqreturn_t res;

@@ -174,6 +177,7 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)

add_interrupt_randomness(irq, flags);

+out:
if (!noirqdebug)
note_interrupt(irq, desc, retval);
return retval;
--
1.7.7.3

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