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 8774ffa9790cabed5a8ed1745d70385823bd9ad6..e5e3fd6b9554318b63ce2e4288f1ff4bcb73c861 100644 (file)
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1467,6 +1467,12 @@ 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 176f5f06432d1acb2e762a223fff9cdb16cab079..205cbd24ff20916028a09328d3db21514a7a88c5 100644 (file)
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1094,6 +1094,12 @@ 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];