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>
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index 2e94eb4..c558e11 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -99,6 +99,3 @@
}
early_initcall(register_trigger_all_cpu_backtrace);
#endif
-
-/* STUB calls to mimic old nmi_watchdog behaviour */
-int unknown_nmi_panic;
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index f02c179..bb6f041 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -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;
}