From acd26bcf362708594ea081ef55140e37d0854ed2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 6 Mar 2020 14:03:47 +0100 Subject: genirq: Provide interrupt injection mechanism Error injection mechanisms need a half ways safe way to inject interrupts as invoking generic_handle_irq() or the actual device interrupt handler directly from e.g. a debugfs write is not guaranteed to be safe. On x86 generic_handle_irq() is unsafe due to the hardware trainwreck which is the base of x86 interrupt delivery and affinity management. Move the irq debugfs injection code into a separate function which can be used by error injection code as well. The implementation prevents at least that state is corrupted, but it cannot close a very tiny race window on x86 which might result in a stale and not serviced device interrupt under very unlikely circumstances. This is explicitly for debugging and testing and not for production use or abuse in random driver code. Signed-off-by: Thomas Gleixner Tested-by: Kuppuswamy Sathyanarayanan Reviewed-by: Kuppuswamy Sathyanarayanan Acked-by: Marc Zyngier Link: https://lkml.kernel.org/r/20200306130623.990928309@linutronix.de --- kernel/irq/internals.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/irq/internals.h') diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 8980859bdf1e..7db284b10ac9 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -108,7 +108,7 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc); irqreturn_t handle_irq_event(struct irq_desc *desc); /* Resending of interrupts :*/ -int check_irq_resend(struct irq_desc *desc); +int check_irq_resend(struct irq_desc *desc, bool inject); bool irq_wait_for_poll(struct irq_desc *desc); void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action); -- cgit