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 f500020d7daf24171b06d28d2e2be7f29a686828..1269284461dae1cc22234f260cb290d14543975f 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 5f22c9d65e57899375f6e0efe258ed7c07182ef0..99077f30f699968a82aa182c928986c041126656 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];