From 5dc3055879b8f659f62abb7c3d1eaa4d02e36d65 Mon Sep 17 00:00:00 2001 From: Don Zickus Date: Mon, 29 Nov 2010 17:07:17 -0500 Subject: [PATCH] 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 Signed-off-by: Don Zickus Reviewed-by: Cyrill Gorcunov Acked-by: Yinghai Lu Cc: fweisbec@gmail.com LKML-Reference: <1291068437-5331-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 10 +--------- arch/x86/kernel/apic/hw_nmi.c | 3 --- arch/x86/kernel/traps.c | 16 +++++++++++----- kernel/sysctl.c | 16 ++++++++++++++++ kernel/sysctl_binary.c | 1 - kernel/watchdog.c | 2 ++ 6 files changed, 30 insertions(+), 18 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index cdd2a6e8a3b7..5e55e4623ab5 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1579,20 +1579,12 @@ and is between 256 and 4096 characters. It is defined in the file 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 diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index 2e94eb493591..c558e1101edf 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -99,6 +99,3 @@ static int __init register_trigger_all_cpu_backtrace(void) } 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 f02c179c2552..bb6f04167361 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -83,6 +83,8 @@ EXPORT_SYMBOL_GPL(used_vectors); 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 @@ gp_in_kernel: 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 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs) 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 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs) 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; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index cbd97da7a613..46404414d8a7 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -745,6 +745,22 @@ static struct ctl_table kern_table[] = { .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) { diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c index 1357c5786064..4b2545a136ff 100644 --- a/kernel/sysctl_binary.c +++ b/kernel/sysctl_binary.c @@ -136,7 +136,6 @@ static const struct bin_table bin_kern_table[] = { { 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" }, {} }; diff --git a/kernel/watchdog.c b/kernel/watchdog.c index cad4e42060a9..eb17e143b5da 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -57,6 +57,8 @@ static int __init hardlockup_panic_setup(char *str) { 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);