ARM: GIC: avoid routing interrupts to offline CPUs
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>
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 635d985..7bdd917 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -179,10 +179,10 @@
{
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 @@
writel_relaxed(val | bit, reg);
spin_unlock(&irq_controller_lock);
- return 0;
+ return IRQ_SET_MASK_OK;
}
#endif