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authorKurt Garloff <garloff@suse.de>2009-06-24 14:32:11 -0700
committerIngo Molnar <mingo@elte.hu>2009-06-25 22:06:11 +0200
commit5211a242d0cbdded372aee59da18f80552b0a80a (patch)
tree5d2a853e538b8478648a57efe94ef049e76e13e6
parent9c26f52b900f7207135bafc8789e1a4f5d43e096 (diff)
x86: Add sysctl to allow panic on IOCK NMI error
This patch introduces a new sysctl: /proc/sys/kernel/panic_on_io_nmi which defaults to 0 (off). When enabled, the kernel panics when the kernel receives an NMI caused by an IO error. The IO error triggered NMI indicates a serious system condition, which could result in IO data corruption. Rather than contiuing, panicing and dumping might be a better choice, so one can figure out what's causing the IO error. This could be especially important to companies running IO intensive applications where corruption must be avoided, e.g. a bank's databases. [ SuSE has been shipping it for a while, it was done at the request of a large database vendor, for their users. ] Signed-off-by: Kurt Garloff <garloff@suse.de> Signed-off-by: Roberto Angelino <robertangelino@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> LKML-Reference: <20090624213211.GA11291@kroah.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/dumpstack.c1
-rw-r--r--arch/x86/kernel/traps.c3
-rw-r--r--include/linux/kernel.h1
-rw-r--r--kernel/sysctl.c8
4 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 95ea5fa7d44..c8405718a4c 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -22,6 +22,7 @@
#include "dumpstack.h"
int panic_on_unrecovered_nmi;
+int panic_on_io_nmi;
unsigned int code_bytes = 64;
int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
static int die_counter;
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a0f48f5671c..5204332f475 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -346,6 +346,9 @@ io_check_error(unsigned char reason, struct pt_regs *regs)
printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n");
show_registers(regs);
+ if (panic_on_io_nmi)
+ panic("NMI IOCK error: Not continuing");
+
/* Re-enable the IOCK line, wait for a few seconds */
reason = (reason & 0xf) | 8;
outb(reason, 0x61);
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index fac104e7186..d6320a3e8de 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -303,6 +303,7 @@ extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in
extern int panic_timeout;
extern int panic_on_oops;
extern int panic_on_unrecovered_nmi;
+extern int panic_on_io_nmi;
extern const char *print_tainted(void);
extern void add_taint(unsigned flag);
extern int test_taint(unsigned flag);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 62e4ff9968b..fba42eda8de 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -744,6 +744,14 @@ static struct ctl_table kern_table[] = {
.proc_handler = &proc_dointvec,
},
{
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "panic_on_io_nmi",
+ .data = &panic_on_io_nmi,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
.ctl_name = KERN_BOOTLOADER_TYPE,
.procname = "bootloader_type",
.data = &bootloader_type,