Revert "x86, nmi_watchdog: Remove the old nmi_watchdog"

This reverts commit 5f2b0ba4d94b3ac23cbc4b7f675d98eb677a760a.

Conflicts:

	arch/x86/kernel/apic/hw_nmi.c

7 files changed, 608 insertions, 5 deletions

diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
index 33292ec848ca..932f0f86b4b7 100644
--- a/arch/x86/include/asm/nmi.h
+++ b/arch/x86/include/asm/nmi.h
@@ -17,6 +17,9 @@ int do_nmi_callback(struct pt_regs *regs, int cpu);
 
 extern void die_nmi(char *str, struct pt_regs *regs, int do_panic);
 extern int check_nmi_watchdog(void);
+#if !defined(CONFIG_LOCKUP_DETECTOR)
+extern int nmi_watchdog_enabled;
+#endif
 extern int avail_to_resrv_perfctr_nmi_bit(unsigned int);
 extern int reserve_perfctr_nmi(unsigned int);
 extern void release_perfctr_nmi(unsigned int);
@@ -27,6 +30,7 @@ extern void setup_apic_nmi_watchdog(void *);
 extern void stop_apic_nmi_watchdog(void *);
 extern void disable_timer_nmi_watchdog(void);
 extern void enable_timer_nmi_watchdog(void);
+extern int nmi_watchdog_tick(struct pt_regs *regs, unsigned reason);
 extern void cpu_nmi_set_wd_enabled(void);
 
 extern atomic_t nmi_active;
diff --git a/arch/x86/kernel/apic/Makefile b/arch/x86/kernel/apic/Makefile
index 3966b564ea47..910f20b457c4 100644
--- a/arch/x86/kernel/apic/Makefile
+++ b/arch/x86/kernel/apic/Makefile
@@ -3,7 +3,10 @@
 #
 
 obj-$(CONFIG_X86_LOCAL_APIC)	+= apic.o apic_noop.o probe_$(BITS).o ipi.o
-obj-y				+= hw_nmi.o
+ifneq ($(CONFIG_HARDLOCKUP_DETECTOR),y)
+obj-$(CONFIG_X86_LOCAL_APIC)	+= nmi.o
+endif
+obj-$(CONFIG_HARDLOCKUP_DETECTOR)	+= hw_nmi.o
 
 obj-$(CONFIG_X86_IO_APIC)	+= io_apic.o
 obj-$(CONFIG_SMP)		+= ipi.o
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index f4a37eb89b49..62f6e1e55b90 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -17,18 +17,16 @@
 #include <linux/nmi.h>
 #include <linux/module.h>
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
 u64 hw_nmi_get_sample_period(void)
 {
 	return (u64)(cpu_khz) * 1000 * 60;
 }
-#endif
 
+#ifdef ARCH_HAS_NMI_WATCHDOG
 
 /* For reliability, we're prepared to waste bits here. */
 static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
 
-#ifdef arch_trigger_all_cpu_backtrace
 void arch_trigger_all_cpu_backtrace(void)
 {
 	int i;
@@ -98,6 +96,8 @@ early_initcall(register_trigger_all_cpu_backtrace);
 #if defined(CONFIG_X86_LOCAL_APIC)
 unsigned int nmi_watchdog = NMI_NONE;
 EXPORT_SYMBOL(nmi_watchdog);
+void acpi_nmi_enable(void) { return; }
+void acpi_nmi_disable(void) { return; }
 #endif
 atomic_t nmi_active = ATOMIC_INIT(0);           /* oprofile uses this */
 EXPORT_SYMBOL(nmi_active);
diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c
new file mode 100644
index 000000000000..c90041ccb742
--- /dev/null
+++ b/arch/x86/kernel/apic/nmi.c
@@ -0,0 +1,567 @@
+/*
+ *  NMI watchdog support on APIC systems
+ *
+ *  Started by Ingo Molnar <mingo@redhat.com>
+ *
+ *  Fixes:
+ *  Mikael Pettersson	: AMD K7 support for local APIC NMI watchdog.
+ *  Mikael Pettersson	: Power Management for local APIC NMI watchdog.
+ *  Mikael Pettersson	: Pentium 4 support for local APIC NMI watchdog.
+ *  Pavel Machek and
+ *  Mikael Pettersson	: PM converted to driver model. Disable/enable API.
+ */
+
+#include <asm/apic.h>
+
+#include <linux/nmi.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sysdev.h>
+#include <linux/sysctl.h>
+#include <linux/percpu.h>
+#include <linux/kprobes.h>
+#include <linux/cpumask.h>
+#include <linux/kernel_stat.h>
+#include <linux/kdebug.h>
+#include <linux/smp.h>
+
+#include <asm/i8259.h>
+#include <asm/io_apic.h>
+#include <asm/proto.h>
+#include <asm/timer.h>
+
+#include <asm/mce.h>
+
+#include <asm/mach_traps.h>
+
+int unknown_nmi_panic;
+int nmi_watchdog_enabled;
+
+/* For reliability, we're prepared to waste bits here. */
+static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
+
+/* nmi_active:
+ * >0: the lapic NMI watchdog is active, but can be disabled
+ * <0: the lapic NMI watchdog has not been set up, and cannot
+ *     be enabled
+ *  0: the lapic NMI watchdog is disabled, but can be enabled
+ */
+atomic_t nmi_active = ATOMIC_INIT(0);		/* oprofile uses this */
+EXPORT_SYMBOL(nmi_active);
+
+unsigned int nmi_watchdog = NMI_NONE;
+EXPORT_SYMBOL(nmi_watchdog);
+
+static int panic_on_timeout;
+
+static unsigned int nmi_hz = HZ;
+static DEFINE_PER_CPU(short, wd_enabled);
+static int endflag __initdata;
+
+static inline unsigned int get_nmi_count(int cpu)
+{
+	return per_cpu(irq_stat, cpu).__nmi_count;
+}
+
+static inline int mce_in_progress(void)
+{
+#if defined(CONFIG_X86_MCE)
+	return atomic_read(&mce_entry) > 0;
+#endif
+	return 0;
+}
+
+/*
+ * Take the local apic timer and PIT/HPET into account. We don't
+ * know which one is active, when we have highres/dyntick on
+ */
+static inline unsigned int get_timer_irqs(int cpu)
+{
+	return per_cpu(irq_stat, cpu).apic_timer_irqs +
+		per_cpu(irq_stat, cpu).irq0_irqs;
+}
+
+#ifdef CONFIG_SMP
+/*
+ * The performance counters used by NMI_LOCAL_APIC don't trigger when
+ * the CPU is idle. To make sure the NMI watchdog really ticks on all
+ * CPUs during the test make them busy.
+ */
+static __init void nmi_cpu_busy(void *data)
+{
+	local_irq_enable_in_hardirq();
+	/*
+	 * Intentionally don't use cpu_relax here. This is
+	 * to make sure that the performance counter really ticks,
+	 * even if there is a simulator or similar that catches the
+	 * pause instruction. On a real HT machine this is fine because
+	 * all other CPUs are busy with "useless" delay loops and don't
+	 * care if they get somewhat less cycles.
+	 */
+	while (endflag == 0)
+		mb();
+}
+#endif
+
+static void report_broken_nmi(int cpu, unsigned int *prev_nmi_count)
+{
+	printk(KERN_CONT "\n");
+
+	printk(KERN_WARNING
+		"WARNING: CPU#%d: NMI appears to be stuck (%d->%d)!\n",
+			cpu, prev_nmi_count[cpu], get_nmi_count(cpu));
+
+	printk(KERN_WARNING
+		"Please report this to bugzilla.kernel.org,\n");
+	printk(KERN_WARNING
+		"and attach the output of the 'dmesg' command.\n");
+
+	per_cpu(wd_enabled, cpu) = 0;
+	atomic_dec(&nmi_active);
+}
+
+static void __acpi_nmi_disable(void *__unused)
+{
+	apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
+}
+
+int __init check_nmi_watchdog(void)
+{
+	unsigned int *prev_nmi_count;
+	int cpu;
+
+	if (!nmi_watchdog_active() || !atomic_read(&nmi_active))
+		return 0;
+
+	prev_nmi_count = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
+	if (!prev_nmi_count)
+		goto error;
+
+	printk(KERN_INFO "Testing NMI watchdog ... ");
+
+#ifdef CONFIG_SMP
+	if (nmi_watchdog == NMI_LOCAL_APIC)
+		smp_call_function(nmi_cpu_busy, (void *)&endflag, 0);
+#endif
+
+	for_each_possible_cpu(cpu)
+		prev_nmi_count[cpu] = get_nmi_count(cpu);
+	local_irq_enable();
+	mdelay((20 * 1000) / nmi_hz); /* wait 20 ticks */
+
+	for_each_online_cpu(cpu) {
+		if (!per_cpu(wd_enabled, cpu))
+			continue;
+		if (get_nmi_count(cpu) - prev_nmi_count[cpu] <= 5)
+			report_broken_nmi(cpu, prev_nmi_count);
+	}
+	endflag = 1;
+	if (!atomic_read(&nmi_active)) {
+		kfree(prev_nmi_count);
+		atomic_set(&nmi_active, -1);
+		goto error;
+	}
+	printk("OK.\n");
+
+	/*
+	 * now that we know it works we can reduce NMI frequency to
+	 * something more reasonable; makes a difference in some configs
+	 */
+	if (nmi_watchdog == NMI_LOCAL_APIC)
+		nmi_hz = lapic_adjust_nmi_hz(1);
+
+	kfree(prev_nmi_count);
+	return 0;
+error:
+	if (nmi_watchdog == NMI_IO_APIC) {
+		if (!timer_through_8259)
+			legacy_pic->mask(0);
+		on_each_cpu(__acpi_nmi_disable, NULL, 1);
+	}
+
+#ifdef CONFIG_X86_32
+	timer_ack = 0;
+#endif
+	return -1;
+}
+
+static int __init setup_nmi_watchdog(char *str)
+{
+	unsigned int nmi;
+
+	if (!strncmp(str, "panic", 5)) {
+		panic_on_timeout = 1;
+		str = strchr(str, ',');
+		if (!str)
+			return 1;
+		++str;
+	}
+
+	if (!strncmp(str, "lapic", 5))
+		nmi_watchdog = NMI_LOCAL_APIC;
+	else if (!strncmp(str, "ioapic", 6))
+		nmi_watchdog = NMI_IO_APIC;
+	else {
+		get_option(&str, &nmi);
+		if (nmi >= NMI_INVALID)
+			return 0;
+		nmi_watchdog = nmi;
+	}
+
+	return 1;
+}
+__setup("nmi_watchdog=", setup_nmi_watchdog);
+
+/*
+ * Suspend/resume support
+ */
+#ifdef CONFIG_PM
+
+static int nmi_pm_active; /* nmi_active before suspend */
+
+static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state)
+{
+	/* only CPU0 goes here, other CPUs should be offline */
+	nmi_pm_active = atomic_read(&nmi_active);
+	stop_apic_nmi_watchdog(NULL);
+	BUG_ON(atomic_read(&nmi_active) != 0);
+	return 0;
+}
+
+static int lapic_nmi_resume(struct sys_device *dev)
+{
+	/* only CPU0 goes here, other CPUs should be offline */
+	if (nmi_pm_active > 0) {
+		setup_apic_nmi_watchdog(NULL);
+		touch_nmi_watchdog();
+	}
+	return 0;
+}
+
+static struct sysdev_class nmi_sysclass = {
+	.name		= "lapic_nmi",
+	.resume		= lapic_nmi_resume,
+	.suspend	= lapic_nmi_suspend,
+};
+
+static struct sys_device device_lapic_nmi = {
+	.id	= 0,
+	.cls	= &nmi_sysclass,
+};
+
+static int __init init_lapic_nmi_sysfs(void)
+{
+	int error;
+
+	/*
+	 * should really be a BUG_ON but b/c this is an
+	 * init call, it just doesn't work.  -dcz
+	 */
+	if (nmi_watchdog != NMI_LOCAL_APIC)
+		return 0;
+
+	if (atomic_read(&nmi_active) < 0)
+		return 0;
+
+	error = sysdev_class_register(&nmi_sysclass);
+	if (!error)
+		error = sysdev_register(&device_lapic_nmi);
+	return error;
+}
+
+/* must come after the local APIC's device_initcall() */
+late_initcall(init_lapic_nmi_sysfs);
+
+#endif	/* CONFIG_PM */
+
+static void __acpi_nmi_enable(void *__unused)
+{
+	apic_write(APIC_LVT0, APIC_DM_NMI);
+}
+
+/*
+ * Enable timer based NMIs on all CPUs:
+ */
+void acpi_nmi_enable(void)
+{
+	if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
+		on_each_cpu(__acpi_nmi_enable, NULL, 1);
+}
+
+/*
+ * Disable timer based NMIs on all CPUs:
+ */
+void acpi_nmi_disable(void)
+{
+	if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
+		on_each_cpu(__acpi_nmi_disable, NULL, 1);
+}
+
+/*
+ * This function is called as soon the LAPIC NMI watchdog driver has everything
+ * in place and it's ready to check if the NMIs belong to the NMI watchdog
+ */
+void cpu_nmi_set_wd_enabled(void)
+{
+	__get_cpu_var(wd_enabled) = 1;
+}
+
+void setup_apic_nmi_watchdog(void *unused)
+{
+	if (__get_cpu_var(wd_enabled))
+		return;
+
+	/* cheap hack to support suspend/resume */
+	/* if cpu0 is not active neither should the other cpus */
+	if (smp_processor_id() != 0 && atomic_read(&nmi_active) <= 0)
+		return;
+
+	switch (nmi_watchdog) {
+	case NMI_LOCAL_APIC:
+		if (lapic_watchdog_init(nmi_hz) < 0) {
+			__get_cpu_var(wd_enabled) = 0;
+			return;
+		}
+		/* FALL THROUGH */
+	case NMI_IO_APIC:
+		__get_cpu_var(wd_enabled) = 1;
+		atomic_inc(&nmi_active);
+	}
+}
+
+void stop_apic_nmi_watchdog(void *unused)
+{
+	/* only support LOCAL and IO APICs for now */
+	if (!nmi_watchdog_active())
+		return;
+	if (__get_cpu_var(wd_enabled) == 0)
+		return;
+	if (nmi_watchdog == NMI_LOCAL_APIC)
+		lapic_watchdog_stop();
+	else
+		__acpi_nmi_disable(NULL);
+	__get_cpu_var(wd_enabled) = 0;
+	atomic_dec(&nmi_active);
+}
+
+/*
+ * the best way to detect whether a CPU has a 'hard lockup' problem
+ * is to check it's local APIC timer IRQ counts. If they are not
+ * changing then that CPU has some problem.
+ *
+ * as these watchdog NMI IRQs are generated on every CPU, we only
+ * have to check the current processor.
+ *
+ * since NMIs don't listen to _any_ locks, we have to be extremely
+ * careful not to rely on unsafe variables. The printk might lock
+ * up though, so we have to break up any console locks first ...
+ * [when there will be more tty-related locks, break them up here too!]
+ */
+
+static DEFINE_PER_CPU(unsigned, last_irq_sum);
+static DEFINE_PER_CPU(long, alert_counter);
+static DEFINE_PER_CPU(int, nmi_touch);
+
+void touch_nmi_watchdog(void)
+{
+	if (nmi_watchdog_active()) {
+		unsigned cpu;
+
+		/*
+		 * Tell other CPUs to reset their alert counters. We cannot
+		 * do it ourselves because the alert count increase is not
+		 * atomic.
+		 */
+		for_each_present_cpu(cpu) {
+			if (per_cpu(nmi_touch, cpu) != 1)
+				per_cpu(nmi_touch, cpu) = 1;
+		}
+	}
+
+	/*
+	 * Tickle the softlockup detector too:
+	 */
+	touch_softlockup_watchdog();
+}
+EXPORT_SYMBOL(touch_nmi_watchdog);
+
+notrace __kprobes int
+nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
+{
+	/*
+	 * Since current_thread_info()-> is always on the stack, and we
+	 * always switch the stack NMI-atomically, it's safe to use
+	 * smp_processor_id().
+	 */
+	unsigned int sum;
+	int touched = 0;
+	int cpu = smp_processor_id();
+	int rc = 0;
+
+	sum = get_timer_irqs(cpu);
+
+	if (__get_cpu_var(nmi_touch)) {
+		__get_cpu_var(nmi_touch) = 0;
+		touched = 1;
+	}
+
+	/* We can be called before check_nmi_watchdog, hence NULL check. */
+	if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
+		static DEFINE_RAW_SPINLOCK(lock); /* Serialise the printks */
+
+		raw_spin_lock(&lock);
+		printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
+		show_regs(regs);
+		dump_stack();
+		raw_spin_unlock(&lock);
+		cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
+
+		rc = 1;
+	}
+
+	/* Could check oops_in_progress here too, but it's safer not to */
+	if (mce_in_progress())
+		touched = 1;
+
+	/* if the none of the timers isn't firing, this cpu isn't doing much */
+	if (!touched && __get_cpu_var(last_irq_sum) == sum) {
+		/*
+		 * Ayiee, looks like this CPU is stuck ...
+		 * wait a few IRQs (5 seconds) before doing the oops ...
+		 */
+		__this_cpu_inc(alert_counter);
+		if (__this_cpu_read(alert_counter) == 5 * nmi_hz)
+			/*
+			 * die_nmi will return ONLY if NOTIFY_STOP happens..
+			 */
+			die_nmi("BUG: NMI Watchdog detected LOCKUP",
+				regs, panic_on_timeout);
+	} else {
+		__get_cpu_var(last_irq_sum) = sum;
+		__this_cpu_write(alert_counter, 0);
+	}
+
+	/* see if the nmi watchdog went off */
+	if (!__get_cpu_var(wd_enabled))
+		return rc;
+	switch (nmi_watchdog) {
+	case NMI_LOCAL_APIC:
+		rc |= lapic_wd_event(nmi_hz);
+		break;
+	case NMI_IO_APIC:
+		/*
+		 * don't know how to accurately check for this.
+		 * just assume it was a watchdog timer interrupt
+		 * This matches the old behaviour.
+		 */
+		rc = 1;
+		break;
+	}
+	return rc;
+}
+
+#ifdef CONFIG_SYSCTL
+
+static void enable_ioapic_nmi_watchdog_single(void *unused)
+{
+	__get_cpu_var(wd_enabled) = 1;
+	atomic_inc(&nmi_active);
+	__acpi_nmi_enable(NULL);
+}
+
+static void enable_ioapic_nmi_watchdog(void)
+{
+	on_each_cpu(enable_ioapic_nmi_watchdog_single, NULL, 1);
+	touch_nmi_watchdog();
+}
+
+static void disable_ioapic_nmi_watchdog(void)
+{
+	on_each_cpu(stop_apic_nmi_watchdog, NULL, 1);
+}
+
+static int __init setup_unknown_nmi_panic(char *str)
+{
+	unknown_nmi_panic = 1;
+	return 1;
+}
+__setup("unknown_nmi_panic", setup_unknown_nmi_panic);
+
+static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
+{
+	unsigned char reason = get_nmi_reason();
+	char buf[64];
+
+	sprintf(buf, "NMI received for unknown reason %02x\n", reason);
+	die_nmi(buf, regs, 1); /* Always panic here */
+	return 0;
+}
+
+/*
+ * proc handler for /proc/sys/kernel/nmi
+ */
+int proc_nmi_enabled(struct ctl_table *table, int write,
+			void __user *buffer, size_t *length, loff_t *ppos)
+{
+	int old_state;
+
+	nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0;
+	old_state = nmi_watchdog_enabled;
+	proc_dointvec(table, write, buffer, length, ppos);
+	if (!!old_state == !!nmi_watchdog_enabled)
+		return 0;
+
+	if (atomic_read(&nmi_active) < 0 || !nmi_watchdog_active()) {
+		printk(KERN_WARNING
+			"NMI watchdog is permanently disabled\n");
+		return -EIO;
+	}
+
+	if (nmi_watchdog == NMI_LOCAL_APIC) {
+		if (nmi_watchdog_enabled)
+			enable_lapic_nmi_watchdog();
+		else
+			disable_lapic_nmi_watchdog();
+	} else if (nmi_watchdog == NMI_IO_APIC) {
+		if (nmi_watchdog_enabled)
+			enable_ioapic_nmi_watchdog();
+		else
+			disable_ioapic_nmi_watchdog();
+	} else {
+		printk(KERN_WARNING
+			"NMI watchdog doesn't know what hardware to touch\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+#endif /* CONFIG_SYSCTL */
+
+int do_nmi_callback(struct pt_regs *regs, int cpu)
+{
+#ifdef CONFIG_SYSCTL
+	if (unknown_nmi_panic)
+		return unknown_nmi_panic_callback(regs, cpu);
+#endif
+	return 0;
+}
+
+void arch_trigger_all_cpu_backtrace(void)
+{
+	int i;
+
+	cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);
+
+	printk(KERN_INFO "sending NMI to all CPUs:\n");
+	apic->send_IPI_all(NMI_VECTOR);
+
+	/* Wait for up to 10 seconds for all CPUs to do the backtrace */
+	for (i = 0; i < 10 * 1000; i++) {
+		if (cpumask_empty(to_cpumask(backtrace_mask)))
+			break;
+		mdelay(1);
+	}
+}
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index db30d9cb9dd6..cb838ca42c96 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -398,6 +398,15 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
 							== NOTIFY_STOP)
 			return;
 
+#ifndef CONFIG_LOCKUP_DETECTOR
+		/*
+		 * Ok, so this is none of the documented NMI sources,
+		 * so it must be the NMI watchdog.
+		 */
+		if (nmi_watchdog_tick(regs, reason))
+			return;
+		if (!do_nmi_callback(regs, cpu))
+#endif /* !CONFIG_LOCKUP_DETECTOR */
 			unknown_nmi_error(reason, regs);
 #else
 		unknown_nmi_error(reason, regs);
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 0cb3e5c246d0..06aab5eee134 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -16,7 +16,10 @@
  */
 #ifdef ARCH_HAS_NMI_WATCHDOG
 #include <asm/nmi.h>
-#endif
+extern void touch_nmi_watchdog(void);
+extern void acpi_nmi_disable(void);
+extern void acpi_nmi_enable(void);
+#else
 #ifndef CONFIG_HARDLOCKUP_DETECTOR
 static inline void touch_nmi_watchdog(void)
 {
@@ -27,6 +30,7 @@ extern void touch_nmi_watchdog(void);
 #endif
 static inline void acpi_nmi_disable(void) { }
 static inline void acpi_nmi_enable(void) { }
+#endif
 
 /*
  * Create trigger_all_cpu_backtrace() out of the arch-provided
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index d91b07d022f7..a00fdefd24ce 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -734,6 +734,22 @@ static struct ctl_table kern_table[] = {
 		.extra2		= &one,
 	},
 #endif
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_LOCKUP_DETECTOR)
+	{
+		.procname       = "unknown_nmi_panic",
+		.data           = &unknown_nmi_panic,
+		.maxlen         = sizeof (int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec,
+	},
+	{
+		.procname       = "nmi_watchdog",
+		.data           = &nmi_watchdog_enabled,
+		.maxlen         = sizeof (int),
+		.mode           = 0644,
+		.proc_handler   = proc_nmi_enabled,
+	},
+#endif
 #if defined(CONFIG_X86)
 	{
 		.procname	= "panic_on_unrecovered_nmi",