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genirq: Robustify handle_percpu_devid_irq() 

The percpu_devid handler is not robust against spurious interrupts. If a
spurious interrupt happens and no action is installed then the handler
crashes with a NULL pointer dereference.

Add a sanity check for this and log the wreckage once in dmesg.

Reported-by: Majun <majun258@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: guohanjun@huawei.com
Cc: dingtianhong@huawei.com
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1609021436160.5647@nanos
This commit is contained in:
Thomas Gleixner 2016-09-02 14:45:19 +02:00
parent eb0dc47ab6
commit fc590c22f9
1 changed files with 14 additions and 4 deletions
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18
kernel/irq/chip.c
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@ -756,7 +756,6 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irqaction *action = desc->action;
void *dev_id = raw_cpu_ptr(action->percpu_dev_id);
unsigned int irq = irq_desc_get_irq(desc);
irqreturn_t res;
@ -765,9 +764,20 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
if (chip->irq_ack)
chip->irq_ack(&desc->irq_data);
trace_irq_handler_entry(irq, action);
res = action->handler(irq, dev_id);
trace_irq_handler_exit(irq, action, res);
if (likely(action)) {
trace_irq_handler_entry(irq, action);
res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
trace_irq_handler_exit(irq, action, res);
} else {
unsigned int cpu = smp_processor_id();
bool enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
if (enabled)
irq_percpu_disable(desc, cpu);
pr_err_once("Spurious%s percpu IRQ%u on CPU%u\n",
enabled ? " and unmasked" : "", irq, cpu);
}
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);