watchdog: make hardlockup detect code public

hulk inclusion
category: feature
bugzilla: 48046
CVE: NA

-------------------------------------------------------------------------

In current code, the hardlockup detect code is contained by
CONFIG_HARDLOCKUP_DETECTOR_PERF. This patch makes this code public so
that other arch hardlockup detector can use it.
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/linux/nmi.h

@@ -7,7 +7,7 @@
 
 #include <linux/sched.h>
 #include <asm/irq.h>
-#if defined(CONFIG_HAVE_NMI_WATCHDOG)
+#if defined(CONFIG_HAVE_NMI_WATCHDOG) && !defined(CONFIG_SDEI_WATCHDOG)
 #include <asm/nmi.h>
 #endif
 
@@ -83,6 +83,7 @@ static inline void reset_hung_task_detector(void) { }
 
 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
 extern void hardlockup_detector_disable(void);
+extern void watchdog_hardlockup_check(struct pt_regs *regs);
 extern unsigned int hardlockup_panic;
 #else
 static inline void hardlockup_detector_disable(void) {}
@@ -94,8 +95,17 @@ static inline void hardlockup_detector_disable(void) {}
 # define NMI_WATCHDOG_SYSCTL_PERM	0444
 #endif
 
-#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
+#if defined(CONFIG_HARDLOCKUP_DETECTOR)
+#ifndef CONFIG_PPC
 extern void arch_touch_nmi_watchdog(void);
+#endif
+#else
+# if !defined(CONFIG_HAVE_NMI_WATCHDOG)
+static inline void arch_touch_nmi_watchdog(void) {}
+# endif
+#endif
+
+#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF)
 extern void hardlockup_detector_perf_stop(void);
 extern void hardlockup_detector_perf_restart(void);
 extern void hardlockup_detector_perf_disable(void);
@@ -110,7 +120,6 @@ static inline void hardlockup_detector_perf_enable(void) { }
 static inline void hardlockup_detector_perf_cleanup(void) { }
 # if !defined(CONFIG_HAVE_NMI_WATCHDOG)
 static inline int hardlockup_detector_perf_init(void) { return -ENODEV; }
-static inline void arch_touch_nmi_watchdog(void) {}
 # else
 static inline int hardlockup_detector_perf_init(void) { return 0; }
 # endif

kernel/Makefile

@@ -89,7 +89,7 @@ obj-$(CONFIG_FAIL_FUNCTION) += fail_function.o
 obj-$(CONFIG_KGDB) += debug/
 obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
 obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o
-obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o
+obj-$(CONFIG_HARDLOCKUP_DETECTOR) += watchdog_hld.o
 obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o

kernel/watchdog_hld.c

@@ -22,14 +22,11 @@
 
 static DEFINE_PER_CPU(bool, hard_watchdog_warn);
 static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
-static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
-static DEFINE_PER_CPU(struct perf_event *, dead_event);
-static struct cpumask dead_events_mask;
 
 static unsigned long hardlockup_allcpu_dumped;
-static atomic_t watchdog_cpus = ATOMIC_INIT(0);
 
-notrace void arch_touch_nmi_watchdog(void)
+#ifndef CONFIG_PPC
+notrace void __weak arch_touch_nmi_watchdog(void)
 {
 	/*
 	 * Using __raw here because some code paths have
@@ -41,6 +38,7 @@ notrace void arch_touch_nmi_watchdog(void)
 	raw_cpu_write(watchdog_nmi_touch, true);
 }
 EXPORT_SYMBOL(arch_touch_nmi_watchdog);
+#endif
 
 #ifdef CONFIG_HARDLOCKUP_CHECK_TIMESTAMP
 static DEFINE_PER_CPU(ktime_t, last_timestamp);
@@ -98,22 +96,8 @@ static inline bool watchdog_check_timestamp(void)
 }
 #endif
 
-static struct perf_event_attr wd_hw_attr = {
-	.type		= PERF_TYPE_HARDWARE,
-	.config		= PERF_COUNT_HW_CPU_CYCLES,
-	.size		= sizeof(struct perf_event_attr),
-	.pinned		= 1,
-	.disabled	= 1,
-};
-
-/* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event,
-				       struct perf_sample_data *data,
-				       struct pt_regs *regs)
+void watchdog_hardlockup_check(struct pt_regs *regs)
 {
-	/* Ensure the watchdog never gets throttled */
-	event->hw.interrupts = 0;
-
 	if (__this_cpu_read(watchdog_nmi_touch) == true) {
 		__this_cpu_write(watchdog_nmi_touch, false);
 		return;
@@ -163,6 +147,31 @@ static void watchdog_overflow_callback(struct perf_event *event,
 	return;
 }
 
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
+static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
+static DEFINE_PER_CPU(struct perf_event *, dead_event);
+static struct cpumask dead_events_mask;
+static atomic_t watchdog_cpus = ATOMIC_INIT(0);
+
+static struct perf_event_attr wd_hw_attr = {
+	.type		= PERF_TYPE_HARDWARE,
+	.config		= PERF_COUNT_HW_CPU_CYCLES,
+	.size		= sizeof(struct perf_event_attr),
+	.pinned		= 1,
+	.disabled	= 1,
+};
+
+/* Callback function for perf event subsystem */
+static void watchdog_overflow_callback(struct perf_event *event,
+				       struct perf_sample_data *data,
+				       struct pt_regs *regs)
+{
+	/* Ensure the watchdog never gets throttled */
+	event->hw.interrupts = 0;
+
+	watchdog_hardlockup_check(regs);
+}
+
 static int hardlockup_detector_event_create(void)
 {
 	unsigned int cpu = smp_processor_id();
@@ -294,3 +303,4 @@ int __init hardlockup_detector_perf_init(void)
 	}
 	return ret;
 }
+#endif /* CONFIG_HARDLOCKUP_DETECTOR_PERF */

lib/Kconfig.debug

@@ -979,7 +979,7 @@ config HARDLOCKUP_DETECTOR
 	bool "Detect Hard Lockups"
 	depends on DEBUG_KERNEL && !S390
 	depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
-	select LOCKUP_DETECTOR
+	select SOFTLOCKUP_DETECTOR
 	select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
 	select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
 	help