From 5dfc54e087c15f823ee9b6541d2f0f314e69cbed Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu, 21 Jul 2011 15:00:57 +0100
Subject: [PATCH] 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>
---
arch/arm/common/gic.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 635d9857b07a..7bdd91766d65 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -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