Messages in this thread | | | Date | Mon, 22 Feb 2021 10:48:11 +0000 | From | Marc Zyngier <> | Subject | Re: [PATCH 5/8] arm64: irq: add a default handle_irq panic function |
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On 2021-02-22 09:59, Mark Rutland wrote: > On Fri, Feb 19, 2021 at 11:39:01AM +0000, Mark Rutland wrote: >> 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. > >> -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"); >> +} > > The kbuild test robot pointed out that this should be static (likewise > with default_handle_fiq in patch 8), since it's only used within this > file, so I've updated that in my branch. > > Mark. > >> + >> +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.");
It also seems odd to have both default_handle_irq() that panics, and init_IRQ that panics as well. Not a big deal, but maybe we should just drop this altogether and get the firework on the first interrupt.
Thanks,
M. -- Jazz is not dead. It just smells funny...
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