x86, NMI: Add back unknown_nmi_panic and nmi_watchdog sysctls

Originally adapted from Huang Ying's patch which moved the unknown_nmi_panic to the traps.c file. Because the old nmi watchdog was deleted before this change happened, the unknown_nmi_panic sysctl was lost. This re-adds it. Also, the nmi_watchdog sysctl was re-implemented and its documentation updated accordingly. Patch-inspired-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: fweisbec@gmail.com LKML-Reference: <1291068437-5331-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86, NMI: Add back unknown_nmi_panic and nmi_watchdog sysctls
Originally adapted from Huang Ying's patch which moved the unknown_nmi_panic to the traps.c file. Because the old nmi watchdog was deleted before this change happened, the unknown_nmi_panic sysctl was lost. This re-adds it. Also, the nmi_watchdog sysctl was re-implemented and its documentation updated accordingly. Patch-inspired-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: fweisbec@gmail.com LKML-Reference: <1291068437-5331-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Don Zickus · Ingo Molnar
1 parent 96a84c20d6
Showing 6 changed files with 30 additions and 18 deletions Side-by-side Diff
Documentation/kernel-parameters.txt
arch/x86/kernel/apic/hw_nmi.c
arch/x86/kernel/traps.c
kernel/sysctl.c
kernel/sysctl_binary.c
kernel/watchdog.c
@@ -1579,20 +1579,12 @@
  
 	nmi_watchdog=	[KNL,BUGS=X86] Debugging features for SMP kernels
 			Format: [panic,][num]
-			Valid num: 0,1,2
+			Valid num: 0
 			0 - turn nmi_watchdog off
-			1 - use the IO-APIC timer for the NMI watchdog
-			2 - use the local APIC for the NMI watchdog using
-			a performance counter. Note: This will use one
-			performance counter and the local APIC's performance
-			vector.
 			When panic is specified, panic when an NMI watchdog
 			timeout occurs.
 			This is useful when you use a panic=... timeout and
 			need the box quickly up again.
-			Instead of 1 and 2 it is possible to use the following
-			symbolic names: lapic and ioapic
-			Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
  
 	netpoll.carrier_timeout=
 			[NET] Specifies amount of time (in seconds) that
@@ -99,7 +99,4 @@
 }
 early_initcall(register_trigger_all_cpu_backtrace);
 #endif
-
-/* STUB calls to mimic old nmi_watchdog behaviour */
-int unknown_nmi_panic;
@@ -83,6 +83,8 @@
  
 static int ignore_nmis;
  
+int unknown_nmi_panic;
+
 static inline void conditional_sti(struct pt_regs *regs)
 {
 	if (regs->flags & X86_EFLAGS_IF)
@@ -300,6 +302,13 @@
 	die("general protection fault", regs, error_code);
 }
  
+static int __init setup_unknown_nmi_panic(char *str)
+{
+	unknown_nmi_panic = 1;
+	return 1;
+}
+__setup("unknown_nmi_panic", setup_unknown_nmi_panic);
+
 static notrace __kprobes void
 mem_parity_error(unsigned char reason, struct pt_regs *regs)
 {
@@ -371,7 +380,7 @@
 			reason, smp_processor_id());
  
 	printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
-	if (panic_on_unrecovered_nmi)
+	if (unknown_nmi_panic || panic_on_unrecovered_nmi)
 		panic("NMI: Not continuing");
  
 	printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
  
@@ -397,11 +406,8 @@
 		if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
 							== NOTIFY_STOP)
 			return;
-
-			unknown_nmi_error(reason, regs);
-#else
-		unknown_nmi_error(reason, regs);
 #endif
+		unknown_nmi_error(reason, regs);
  
 		return;
 	}
@@ -745,6 +745,22 @@
 		.extra1		= &zero,
 		.extra2		= &one,
 	},
+	{
+		.procname       = "nmi_watchdog",
+		.data           = &watchdog_enabled,
+		.maxlen         = sizeof (int),
+		.mode           = 0644,
+		.proc_handler   = proc_dowatchdog_enabled,
+	},
+#endif
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
+	{
+		.procname       = "unknown_nmi_panic",
+		.data           = &unknown_nmi_panic,
+		.maxlen         = sizeof (int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec,
+	},
 #endif
 #if defined(CONFIG_X86)
 	{
@@ -136,7 +136,6 @@
 	{ CTL_INT,	KERN_IA64_UNALIGNED,		"ignore-unaligned-usertrap" },
 	{ CTL_INT,	KERN_COMPAT_LOG,		"compat-log" },
 	{ CTL_INT,	KERN_MAX_LOCK_DEPTH,		"max_lock_depth" },
-	{ CTL_INT,	KERN_NMI_WATCHDOG,		"nmi_watchdog" },
 	{ CTL_INT,	KERN_PANIC_ON_NMI,		"panic_on_unrecovered_nmi" },
 	{}
 };
@@ -57,6 +57,8 @@
 {
 	if (!strncmp(str, "panic", 5))
 		hardlockup_panic = 1;
+	else if (!strncmp(str, "0", 1))
+		no_watchdog = 1;
 	return 1;
 }
 __setup("nmi_watchdog=", hardlockup_panic_setup);
...	...	@@ -1579,20 +1579,12 @@
1579	1579
1580	1580	nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
1581	1581	Format: [panic,][num]
1582		- Valid num: 0,1,2
	1582	+ Valid num: 0
1583	1583	0 - turn nmi_watchdog off
1584		- 1 - use the IO-APIC timer for the NMI watchdog
1585		- 2 - use the local APIC for the NMI watchdog using
1586		- a performance counter. Note: This will use one
1587		- performance counter and the local APIC's performance
1588		- vector.
1589	1584	When panic is specified, panic when an NMI watchdog
1590	1585	timeout occurs.
1591	1586	This is useful when you use a panic=... timeout and
1592	1587	need the box quickly up again.
1593		- Instead of 1 and 2 it is possible to use the following
1594		- symbolic names: lapic and ioapic
1595		- Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
1596	1588
1597	1589	netpoll.carrier_timeout=
1598	1590	[NET] Specifies amount of time (in seconds) that
...	...	@@ -99,7 +99,4 @@
99	99	}
100	100	early_initcall(register_trigger_all_cpu_backtrace);
101	101	#endif
102		-
103		-/* STUB calls to mimic old nmi_watchdog behaviour */
104		-int unknown_nmi_panic;
...	...	@@ -83,6 +83,8 @@
83	83
84	84	static int ignore_nmis;
85	85
	86	+int unknown_nmi_panic;
	87	+
86	88	static inline void conditional_sti(struct pt_regs *regs)
87	89	{
88	90	if (regs->flags & X86_EFLAGS_IF)
...	...	@@ -300,6 +302,13 @@
300	302	die("general protection fault", regs, error_code);
301	303	}
302	304
	305	+static int __init setup_unknown_nmi_panic(char *str)
	306	+{
	307	+ unknown_nmi_panic = 1;
	308	+ return 1;
	309	+}
	310	+__setup("unknown_nmi_panic", setup_unknown_nmi_panic);
	311	+
303	312	static notrace __kprobes void
304	313	mem_parity_error(unsigned char reason, struct pt_regs *regs)
305	314	{
...	...	@@ -371,7 +380,7 @@
371	380	reason, smp_processor_id());
372	381
373	382	printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
374		- if (panic_on_unrecovered_nmi)
	383	+ if (unknown_nmi_panic \|\| panic_on_unrecovered_nmi)
375	384	panic("NMI: Not continuing");
376	385
377	386	printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
378	387
...	...	@@ -397,11 +406,8 @@
397	406	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
398	407	== NOTIFY_STOP)
399	408	return;
400		-
401		- unknown_nmi_error(reason, regs);
402		-#else
403		- unknown_nmi_error(reason, regs);
404	409	#endif
	410	+ unknown_nmi_error(reason, regs);
405	411
406	412	return;
407	413	}
...	...	@@ -745,6 +745,22 @@
745	745	.extra1 = &zero,
746	746	.extra2 = &one,
747	747	},
	748	+ {
	749	+ .procname = "nmi_watchdog",
	750	+ .data = &watchdog_enabled,
	751	+ .maxlen = sizeof (int),
	752	+ .mode = 0644,
	753	+ .proc_handler = proc_dowatchdog_enabled,
	754	+ },
	755	+#endif
	756	+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
	757	+ {
	758	+ .procname = "unknown_nmi_panic",
	759	+ .data = &unknown_nmi_panic,
	760	+ .maxlen = sizeof (int),
	761	+ .mode = 0644,
	762	+ .proc_handler = proc_dointvec,
	763	+ },
748	764	#endif
749	765	#if defined(CONFIG_X86)
750	766	{
...	...	@@ -136,7 +136,6 @@
136	136	{ CTL_INT, KERN_IA64_UNALIGNED, "ignore-unaligned-usertrap" },
137	137	{ CTL_INT, KERN_COMPAT_LOG, "compat-log" },
138	138	{ CTL_INT, KERN_MAX_LOCK_DEPTH, "max_lock_depth" },
139		- { CTL_INT, KERN_NMI_WATCHDOG, "nmi_watchdog" },
140	139	{ CTL_INT, KERN_PANIC_ON_NMI, "panic_on_unrecovered_nmi" },
141	140	{}
142	141	};
...	...	@@ -57,6 +57,8 @@
57	57	{
58	58	if (!strncmp(str, "panic", 5))
59	59	hardlockup_panic = 1;
	60	+ else if (!strncmp(str, "0", 1))
	61	+ no_watchdog = 1;
60	62	return 1;
61	63	}
62	64	__setup("nmi_watchdog=", hardlockup_panic_setup);