ARM: GIC: avoid routing interrupts to offline CPUs (5dfc54e0) · Commits · 戴 / test

The irq_set_affinity() method can be called with masks which include offline CPUs. This allows offline CPUs to have interrupts routed to them by writing to /proc/irq/*/smp_affinity after hotplug has taken a CPU offline. Fix this by ensuring that we select a target CPU present in both the required affinity and the online CPU mask. Ensure that we return IRQ_SET_MASK_OK (which happens to be 0) on success to ensure generic code copies the new mask into the irq_data structure. Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/common/gic.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -179,10 +179,10 @@ static int gic_set_affinity(struct irq_data d, const struct cpumask mask_val,
		{
		void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
		unsigned int shift = (d->irq % 4) * 8;
		unsigned int cpu = cpumask_first(mask_val);
		unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
		u32 val, mask, bit;

		if (cpu >= 8)
		if (cpu >= 8 \|\| cpu >= nr_cpu_ids)
		return -EINVAL;

		mask = 0xff << shift;
		@@ -193,7 +193,7 @@ static int gic_set_affinity(struct irq_data d, const struct cpumask mask_val,
		writel_relaxed(val \| bit, reg);
		spin_unlock(&irq_controller_lock);

		return 0;
		return IRQ_SET_MASK_OK;
		}
		#endif

Admin message