Patch "genirq: Guard handle_bad_irq log messages" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

genirq: Guard handle_bad_irq log messages

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
genirq-guard-handle_bad_irq-log-messages.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Guenter Roeck <[email protected]>
Date: Sat, 2 Dec 2017 09:13:04 -0800
Subject: genirq: Guard handle_bad_irq log messages

From: Guenter Roeck <[email protected]>

[ Upstream commit 11bca0a83f83f6093d816295668e74ef24595944 ]

An interrupt storm on a bad interrupt will cause the kernel log to be clogged.

[   60.089234] ->handle_irq():  ffffffffbe2f803f,
[   60.090455] 0xffffffffbf2af380
[   60.090510] handle_bad_irq+0x0/0x2e5
[   60.090522] ->irq_data.chip(): ffffffffbf2af380,
[   60.090553]    IRQ_NOPROBE set
[   60.090584] ->handle_irq():  ffffffffbe2f803f,
[   60.090590] handle_bad_irq+0x0/0x2e5
[   60.090596] ->irq_data.chip(): ffffffffbf2af380,
[   60.090602] 0xffffffffbf2af380
[   60.090608] ->action():           (null)
[   60.090779] handle_bad_irq+0x0/0x2e5

This was seen when running an upstream kernel on Acer Chromebook R11. The system was unstable as result.

Guard the log message with __printk_ratelimit to reduce the impact. This won't prevent the interrupt storm from happening, but at least the system remains stable.

---
 kernel/irq/debug.h |    5 +++++
 1 file changed, 5 insertions(+)

@@ -12,6 +12,11 @@
 
 static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
 {
+	static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
+
+	if (!__ratelimit(&ratelimit))
+		return;
+
 	printk("irq %d, desc: %p, depth: %d, count: %d, unhandled: %d\n",
 		irq, desc, desc->depth, desc->irq_count, desc->irqs_unhandled);
 	printk("->handle_irq():  %p, ", desc->handle_irq);

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/genirq-guard-handle_bad_irq-log-messages.patch