diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 8b961ad..400b12a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -357,6 +357,7 @@
 	struct irq_desc *desc;
 	struct irqaction **p;
 	unsigned long flags;
+	irqreturn_t (*handler)(int, void *) = NULL;
 
 	WARN_ON(in_interrupt());
 	if (irq >= NR_IRQS)
@@ -396,6 +397,8 @@
 
 			/* Make sure it's not being used on another CPU */
 			synchronize_irq(irq);
+			if (action->flags & IRQF_SHARED)
+				handler = action->handler;
 			kfree(action);
 			return;
 		}
@@ -403,6 +406,17 @@
 		spin_unlock_irqrestore(&desc->lock, flags);
 		return;
 	}
+#ifdef CONFIG_DEBUG_SHIRQ
+	if (handler) {
+		/*
+		 * It's a shared IRQ -- the driver ought to be prepared for it
+		 * to happen even now it's being freed, so let's make sure....
+		 * We do this after actually deregistering it, to make sure that
+		 * a 'real' IRQ doesn't run in parallel with our fake
+		 */
+		handler(irq, dev_id);
+	}
+#endif
 }
 EXPORT_SYMBOL(free_irq);
 
@@ -475,6 +489,25 @@
 
 	select_smp_affinity(irq);
 
+#ifdef CONFIG_DEBUG_SHIRQ
+	if (irqflags & IRQF_SHARED) {
+		/*
+		 * It's a shared IRQ -- the driver ought to be prepared for it
+		 * to happen immediately, so let's make sure....
+		 * We do this before actually registering it, to make sure that
+		 * a 'real' IRQ doesn't run in parallel with our fake
+		 */
+		if (irqflags & IRQF_DISABLED) {
+			unsigned long flags;
+
+			local_irq_save(flags);
+			handler(irq, dev_id);
+			local_irq_restore(flags);
+		} else
+			handler(irq, dev_id);
+	}
+#endif
+
 	retval = setup_irq(irq, action);
 	if (retval)
 		kfree(action);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 356a5ab..63f04c1 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -77,6 +77,15 @@
 	  Say Y here if you are developing drivers or trying to debug and
 	  identify kernel problems.
 
+config DEBUG_SHIRQ
+	bool "Debug shared IRQ handlers"
+	depends on DEBUG_KERNEL && GENERIC_HARDIRQS
+	help
+	  Enable this to generate a spurious interrupt as soon as a shared
+	  interrupt handler is registered, and just before one is deregistered.
+	  Drivers ought to be able to handle interrupts coming in at those
+	  points; some don't and need to be caught.
+
 config LOG_BUF_SHIFT
 	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
 	range 12 21