Commit-ID: fc590c22f9f056ab50190b797f6cacead29f9b75
Gitweb: http://git.kernel.org/tip/fc590c22f9f056ab50190b797f6cacead29f9b75
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Fri, 2 Sep 2016 14:45:19 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 2 Sep 2016 18:06:49 +0200
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@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: guohanjun@xxxxxxxxxx
Cc: dingtianhong@xxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1609021436160.5647@nanos
---
kernel/irq/chip.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index b4c1bc7..93c373a 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);
--
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