irqchip/gic, gic-v3: Prevent GSI to SGI translations

commit 544808f7e21cb9ccdb8f3aa7de594c05b1419061 upstream.

At the moment the GIC IRQ domain translation routine happily converts
ACPI table GSI numbers below 16 to GIC SGIs (Software Generated
Interrupts aka IPIs). On the Devicetree side we explicitly forbid this
translation, actually the function will never return HWIRQs below 16 when
using a DT based domain translation.

We expect SGIs to be handled in the first part of the function, and any
further occurrence should be treated as a firmware bug, so add a check
and print to report this explicitly and avoid lengthy debug sessions.

Fixes: 64b499d8df40 ("irqchip/gic-v3: Configure SGIs as standard interrupts")
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220404110842.2882446-1-andre.przywara@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 7c1e9953bb9224c294357f29ec645c264ff61af1..b93dd5b9f83d0447cf5f5a3a8606d5dc57a65f44 100644 (file)
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1466,6 +1466,12 @@ static int gic_irq_domain_translate(struct irq_domain *d,
                if(fwspec->param_count != 2)
                        return -EINVAL;
 
+               if (fwspec->param[0] < 16) {
+                       pr_err(FW_BUG "Illegal GSI%d translation request\n",
+                              fwspec->param[0]);
+                       return -EINVAL;
+               }
+
                *hwirq = fwspec->param[0];
                *type = fwspec->param[1];
 

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index b8bb46c65a97a35747b3bc2be601ba57e73e79ed..3dbac62c932dd6886df59cba8cf552d1a53fcb32 100644 (file)
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1085,6 +1085,12 @@ static int gic_irq_domain_translate(struct irq_domain *d,
                if(fwspec->param_count != 2)
                        return -EINVAL;
 
+               if (fwspec->param[0] < 16) {
+                       pr_err(FW_BUG "Illegal GSI%d translation request\n",
+                              fwspec->param[0]);
+                       return -EINVAL;
+               }
+
                *hwirq = fwspec->param[0];
                *type = fwspec->param[1];