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authorThomas Gleixner <tglx@linutronix.de>2016-09-02 14:45:19 +0200
committerThomas Gleixner <tglx@linutronix.de>2016-09-02 18:06:49 +0200
commitfc590c22f9f056ab50190b797f6cacead29f9b75 (patch)
tree87719f60da441d05d0ea7f16fb3ba4d926491f5f /kernel/irq/chip.c
parenteb0dc47ab6810c432e8193beccd9905ba0db8b22 (diff)
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
Diffstat (limited to 'kernel/irq/chip.c')
-rw-r--r--kernel/irq/chip.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index b4c1bc7c9ca2..93c373a8b12b 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -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);