[PATCH 9/9] watchdog: skip checks when panic is in progress

[Jinchao Wang <wangjinchao600@gmail.com>]

Both watchdog_buddy_check_hardlockup() and
watchdog_overflow_callback() may trigger
during a panic. This can lead to recursive
panic handling.

Add panic_in_progress() checks so watchdog
activity is skipped once a panic has begun.

This prevents recursive panic and keeps the
panic path more reliable.

Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
---
 kernel/watchdog_buddy.c | 5 +++++
 kernel/watchdog_perf.c  | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/kernel/watchdog_buddy.c b/kernel/watchdog_buddy.c
index ee754d767c21..79a85623028c 100644
--- a/kernel/watchdog_buddy.c
+++ b/kernel/watchdog_buddy.c
@@ -93,6 +93,11 @@ void watchdog_buddy_check_hardlockup(int hrtimer_interrupts)
 	 */
 	if (hrtimer_interrupts % 3 != 0)
 		return;
+	/*
+	 * pass the buddy check if a panic is in process
+	 */
+	if (panic_in_progress())
+		return;
 
 	/* check for a hardlockup on the next CPU */
 	next_cpu = watchdog_next_cpu(smp_processor_id());
diff --git a/kernel/watchdog_perf.c b/kernel/watchdog_perf.c
index 9c58f5b4381d..7641de750ca5 100644
--- a/kernel/watchdog_perf.c
+++ b/kernel/watchdog_perf.c
@@ -12,6 +12,7 @@
 
 #define pr_fmt(fmt) "NMI watchdog: " fmt
 
+#include <linux/panic.h>
 #include <linux/nmi.h>
 #include <linux/atomic.h>
 #include <linux/module.h>
@@ -110,6 +111,8 @@ static void watchdog_overflow_callback(struct perf_event *event,
 
 	if (!watchdog_check_timestamp())
 		return;
+	if (panic_in_progress())
+		return;
 
 	watchdog_hardlockup_check(smp_processor_id(), regs);
 }
-- 
2.43.0