Commit-ID: fc590c22f9f056ab50190b797f6cacead29f9b75 Gitweb: http://git.kernel.org/tip/fc590c22f9f056ab50190b797f6cacead29f9b75 Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Fri, 2 Sep 2016 14:45:19 +0200 Committer: Thomas Gleixner <t...@linutronix.de> 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 <majun...@huawei.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: Mark Rutland <mark.rutl...@arm.com> Cc: Marc Zyngier <marc.zyng...@arm.com> Cc: guohan...@huawei.com Cc: dingtianh...@huawei.com Cc: linux-arm-ker...@lists.infradead.org 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);
