[PATCH 4.9 32/56] genirq: Guard handle_bad_irq log messages

Greg Kroah-Hartman
2018-03-02T08:51:18Z

From: Guenter Roeck <linux@roeck-us.net>

[ 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.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197953
Link: https://lkml.kernel.org/r/1512234784-21038-1-git-send-email-linux@roeck-us.net
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/irq/debug.h | 5 +++++
1 file changed, 5 insertions(+)

--- a/kernel/irq/debug.h
+++ b/kernel/irq/debug.h
@@ -11,6 +11,11 @@

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);