If we accidentally unmask IRQs before we've registered an IRQ
controller, handle_arch_irq will be NULL, and the IRQ exception handler
will branch to a bogus address.
To make this easier to debug, this patch initialises handle_arch_irq to
a default handler which will panic(), making such problems easier to
debug. When we add support for FIQ handlers, we can follow the same
approach.
Signed-off-by: Mark Rutland <mark.rutl...@arm.com>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Hector Martin <mar...@marcan.st>
Cc: James Morse <james.mo...@arm.com>
Cc: Marc Zyngier <m...@kernel.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Will Deacon <w...@kernel.org>
---
arch/arm64/kernel/irq.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index ad63bd50fa7b..00bcf37aa0ea 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -71,11 +71,16 @@ static void init_irq_stacks(void)
}
#endif
-void (*handle_arch_irq)(struct pt_regs *) __ro_after_init;
+void default_handle_irq(struct pt_regs *regs)
+{
+ panic("IRQ taken without a registered IRQ controller\n");
+}
+
+void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq;
int __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
{
- if (handle_arch_irq)
+ if (handle_arch_irq != default_handle_irq)
return -EBUSY;
handle_arch_irq = handle_irq;
@@ -87,7 +92,7 @@ void __init init_IRQ(void)
init_irq_stacks();
init_irq_scs();
irqchip_init();
- if (!handle_arch_irq)
+ if (handle_arch_irq == default_handle_irq)
panic("No interrupt controller found.");
if (system_uses_irq_prio_masking()) {
--
2.11.0
