X-Git-Url: https://rtime.felk.cvut.cz/gitweb/zynq/linux.git/blobdiff_plain/b450e900fdb473a53613ad014f31eedbc80b1c90..aebcc440d27130c7bfb8868bc7246698e76d5f45:/kernel/watchdog.c

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9acb29f280ec..caba62080411 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -315,6 +315,8 @@ static int is_softlockup(unsigned long touch_ts)
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 
+static DEFINE_RAW_SPINLOCK(watchdog_output_lock);
+
 static struct perf_event_attr wd_hw_attr = {
 	.type		= PERF_TYPE_HARDWARE,
 	.config		= PERF_COUNT_HW_CPU_CYCLES,
@@ -349,6 +351,13 @@ static void watchdog_overflow_callback(struct perf_event *event,
 		/* only print hardlockups once */
 		if (__this_cpu_read(hard_watchdog_warn) == true)
 			return;
+		/*
+		 * If early-printk is enabled then make sure we do not
+		 * lock up in printk() and kill console logging:
+		 */
+		printk_kill();
+
+		raw_spin_lock(&watchdog_output_lock);
 
 		pr_emerg("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
 		print_modules();
@@ -366,6 +375,7 @@ static void watchdog_overflow_callback(struct perf_event *event,
 				!test_and_set_bit(0, &hardlockup_allcpu_dumped))
 			trigger_allbutself_cpu_backtrace();
 
+		raw_spin_unlock(&watchdog_output_lock);
 		if (hardlockup_panic)
 			nmi_panic(regs, "Hard LOCKUP");
 
@@ -513,6 +523,7 @@ static void watchdog_enable(unsigned int cpu)
 	/* kick off the timer for the hardlockup detector */
 	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hrtimer->function = watchdog_timer_fn;
+	hrtimer->irqsafe = 1;
 
 	/* Enable the perf event */
 	watchdog_nmi_enable(cpu);