From 8da5adda91df3d2fcc5300e68da491694c9af019 Mon Sep 17 00:00:00 2001 From: Don Zickus Date: Tue, 26 Sep 2006 10:52:27 +0200 Subject: [PATCH] [PATCH] x86: Allow users to force a panic on NMI To quote Alan Cox: The default Linux behaviour on an NMI of either memory or unknown is to continue operation. For many environments such as scientific computing it is preferable that the box is taken out and the error dealt with than an uncorrected parity/ECC error get propogated. A small number of systems do generate NMI's for bizarre random reasons such as power management so the default is unchanged. In other respects the new proc/sys entry works like the existing panic controls already in that directory. This is separate to the edac support - EDAC allows supported chipsets to handle ECC errors well, this change allows unsupported cases to at least panic rather than cause problems further down the line. Signed-off-by: Don Zickus Signed-off-by: Andi Kleen --- arch/i386/kernel/traps.c | 6 ++++++ arch/x86_64/kernel/traps.c | 6 ++++++ include/linux/kernel.h | 1 + include/linux/sysctl.h | 1 + kernel/panic.c | 1 + kernel/sysctl.c | 8 ++++++++ 6 files changed, 23 insertions(+) diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 7db664d..2f6cb82 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -635,6 +635,8 @@ static void mem_parity_error(unsigned char reason, struct pt_regs * regs) "to continue\n"); printk(KERN_EMERG "You probably have a hardware problem with your RAM " "chips\n"); + if (panic_on_unrecovered_nmi) + panic("NMI: Not continuing"); /* Clear and disable the memory parity error line. */ clear_mem_error(reason); @@ -670,6 +672,10 @@ static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) reason, smp_processor_id()); printk("Dazed and confused, but trying to continue\n"); printk("Do you have a strange power saving mode enabled?\n"); + + if (panic_on_unrecovered_nmi) + panic("NMI: Not continuing"); + } static DEFINE_SPINLOCK(nmi_print_lock); diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index 42bc070..b18829d 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -732,6 +732,8 @@ mem_parity_error(unsigned char reason, struct pt_regs * regs) { printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n"); printk("You probably have a hardware problem with your RAM chips\n"); + if (panic_on_unrecovered_nmi) + panic("NMI: Not continuing"); /* Clear and disable the memory parity error line. */ reason = (reason & 0xf) | 4; @@ -757,6 +759,10 @@ unknown_nmi_error(unsigned char reason, struct pt_regs * regs) { printk("Uhhuh. NMI received for unknown reason %02x.\n", reason); printk("Dazed and confused, but trying to continue\n"); printk("Do you have a strange power saving mode enabled?\n"); + + if (panic_on_unrecovered_nmi) + panic("NMI: Not continuing"); + } /* Runs on IST stack. This code must keep interrupts off all the time. diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2b2ae4f..1ff9609 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -186,6 +186,7 @@ extern void bust_spinlocks(int yes); extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ extern int panic_timeout; extern int panic_on_oops; +extern int panic_on_unrecovered_nmi; extern int tainted; extern const char *print_tainted(void); extern void add_taint(unsigned); diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index ecb79ba..4327784 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -151,6 +151,7 @@ enum KERN_COMPAT_LOG=73, /* int: print compat layer messages */ KERN_MAX_LOCK_DEPTH=74, KERN_NMI_WATCHDOG=75, /* int: enable/disable nmi watchdog */ + KERN_PANIC_ON_NMI=76, /* int: whether we will panic on an unrecovered */ }; diff --git a/kernel/panic.c b/kernel/panic.c index 8010b9b..d2db3e2 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -21,6 +21,7 @@ #include int panic_on_oops; +int panic_on_unrecovered_nmi; int tainted; static int pause_on_oops; static int pause_on_oops_flag; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 040de6b..220e205 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -642,6 +642,14 @@ static ctl_table kern_table[] = { #endif #if defined(CONFIG_X86) { + .ctl_name = KERN_PANIC_ON_NMI, + .procname = "panic_on_unrecovered_nmi", + .data = &panic_on_unrecovered_nmi, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, + { .ctl_name = KERN_BOOTLOADER_TYPE, .procname = "bootloader_type", .data = &bootloader_type, -- 2.7.4