Re: 2.6.7-rc2-mm2
From: AKIYAMA Nobuyuki
Date: Thu Jun 03 2004 - 10:37:16 EST
On Thu, 03 Jun 2004 01:53:56 -0700
Andrew Morton <akpm@xxxxxxxx> wrote:
(snip)
> -nmi-trigger-switch-support-for-debugging.patch
>
> Dropped - was causing various build problems.
I fixed the issue and remade a patch against -mm2.
I have tested various configurations and I have no problem now.
A document(proc.txt) is attached too.
Thanks,
Nobuyuki Akiyama
====
diff -Nur linux-2.6.7-rc2-mm2.org/arch/i386/kernel/nmi.c linux-2.6.7-rc2-mm2/arch/i386/kernel/nmi.c
--- linux-2.6.7-rc2-mm2.org/arch/i386/kernel/nmi.c 2004-06-03 19:16:13.000000000 +0900
+++ linux-2.6.7-rc2-mm2/arch/i386/kernel/nmi.c 2004-06-03 19:43:29.000000000 +0900
@@ -25,12 +25,15 @@
#include <linux/module.h>
#include <linux/nmi.h>
#include <linux/sysdev.h>
+#include <linux/sysctl.h>
#include <asm/smp.h>
#include <asm/mtrr.h>
#include <asm/mpspec.h>
#include <asm/nmi.h>
+#include "mach_traps.h"
+
#ifdef CONFIG_KGDB
#include <asm/kgdb.h>
#ifdef CONFIG_SMP
@@ -42,6 +45,8 @@
unsigned int nmi_watchdog = NMI_NONE;
#endif
+int unknown_nmi_panic;
+
static unsigned int nmi_hz = HZ;
static unsigned int nmi_perfctr_msr; /* the MSR to reset in NMI handler */
static unsigned int nmi_p4_cccr_val;
@@ -436,8 +441,6 @@
nmi_active = 1;
}
-static spinlock_t nmi_print_lock = SPIN_LOCK_UNLOCKED;
-
/*
* the best way to detect whether a CPU has a 'hard lockup' problem
* is to check it's local APIC timer IRQ counts. If they are not
@@ -472,6 +475,8 @@
int tune_watchdog = 5*HZ;
#endif
+extern void die_nmi(struct pt_regs *, const char *msg);
+
void nmi_watchdog_tick (struct pt_regs * regs)
{
@@ -502,21 +507,8 @@
alert_counter[cpu] = 0;
}
#endif
- if (alert_counter[cpu] == 5*nmi_hz) {
- spin_lock(&nmi_print_lock);
- /*
- * We are in trouble anyway, lets at least try
- * to get a message out.
- */
- bust_spinlocks(1);
- printk("NMI Watchdog detected LOCKUP on CPU%d, eip %08lx, registers:\n", cpu, regs->eip);
- show_registers(regs);
- printk("console shuts up ...\n");
- console_silent();
- spin_unlock(&nmi_print_lock);
- bust_spinlocks(0);
- do_exit(SIGSEGV);
- }
+ if (alert_counter[cpu] == 5*nmi_hz)
+ die_nmi(regs, "NMI Watchdog detected LOCKUP");
} else {
last_irq_sums[cpu] = sum;
alert_counter[cpu] = 0;
@@ -543,6 +535,45 @@
}
}
+static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
+{
+ unsigned char reason = get_nmi_reason();
+ char buf[64];
+
+ if (!(reason & 0xc0)) {
+ sprintf(buf, "NMI received for unknown reason %02x\n", reason);
+ die_nmi(regs, buf);
+ }
+ return 0;
+}
+
+/*
+ * proc handler for /proc/sys/kernel/unknown_nmi_panic
+ */
+int proc_unknown_nmi_panic(ctl_table *table, int write,
+ struct file *file, void __user *buffer, size_t *length)
+{
+ int old_state;
+
+ old_state = unknown_nmi_panic;
+ proc_dointvec(table, write, file, buffer, length);
+ if (!!old_state == !!unknown_nmi_panic)
+ return 0;
+
+ if (unknown_nmi_panic) {
+ if (reserve_lapic_nmi() < 0) {
+ unknown_nmi_panic = 0;
+ return -EBUSY;
+ } else {
+ set_nmi_callback(unknown_nmi_panic_callback);
+ }
+ } else {
+ release_lapic_nmi();
+ unset_nmi_callback();
+ }
+ return 0;
+}
+
EXPORT_SYMBOL(nmi_active);
EXPORT_SYMBOL(nmi_watchdog);
EXPORT_SYMBOL(reserve_lapic_nmi);
diff -Nur linux-2.6.7-rc2-mm2.org/arch/i386/kernel/traps.c linux-2.6.7-rc2-mm2/arch/i386/kernel/traps.c
--- linux-2.6.7-rc2-mm2.org/arch/i386/kernel/traps.c 2004-06-03 19:16:13.000000000 +0900
+++ linux-2.6.7-rc2-mm2/arch/i386/kernel/traps.c 2004-06-03 19:18:00.000000000 +0900
@@ -547,6 +547,27 @@
printk("Do you have a strange power saving mode enabled?\n");
}
+static spinlock_t nmi_print_lock = SPIN_LOCK_UNLOCKED;
+
+void die_nmi (struct pt_regs *regs, const char *msg)
+{
+ spin_lock(&nmi_print_lock);
+ /*
+ * We are in trouble anyway, lets at least try
+ * to get a message out.
+ */
+ bust_spinlocks(1);
+ printk(msg);
+ printk(" on CPU%d, eip %08lx, registers:\n",
+ smp_processor_id(), regs->eip);
+ show_registers(regs);
+ printk("console shuts up ...\n");
+ console_silent();
+ spin_unlock(&nmi_print_lock);
+ bust_spinlocks(0);
+ do_exit(SIGSEGV);
+}
+
static void default_do_nmi(struct pt_regs * regs)
{
unsigned char reason = get_nmi_reason();
diff -Nur linux-2.6.7-rc2-mm2.org/include/linux/sysctl.h linux-2.6.7-rc2-mm2/include/linux/sysctl.h
--- linux-2.6.7-rc2-mm2.org/include/linux/sysctl.h 2004-06-03 19:16:29.000000000 +0900
+++ linux-2.6.7-rc2-mm2/include/linux/sysctl.h 2004-06-03 19:18:00.000000000 +0900
@@ -133,6 +133,7 @@
KERN_NGROUPS_MAX=63, /* int: NGROUPS_MAX */
KERN_SPARC_SCONS_PWROFF=64, /* int: serial console power-off halt */
KERN_HZ_TIMER=65, /* int: hz timer on or off */
+ KERN_UNKNOWN_NMI_PANIC=66, /* int: unknown nmi panic flag */
};
diff -Nur linux-2.6.7-rc2-mm2.org/kernel/sysctl.c linux-2.6.7-rc2-mm2/kernel/sysctl.c
--- linux-2.6.7-rc2-mm2.org/kernel/sysctl.c 2004-06-03 19:16:20.000000000 +0900
+++ linux-2.6.7-rc2-mm2/kernel/sysctl.c 2004-06-03 19:48:23.000000000 +0900
@@ -63,6 +63,12 @@
extern int printk_ratelimit_jiffies;
extern int printk_ratelimit_burst;
+#if defined(CONFIG_X86_LOCAL_APIC)
+extern int unknown_nmi_panic;
+extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *,
+ void __user *, size_t *);
+#endif
+
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
static int minolduid;
@@ -618,6 +624,16 @@
.mode = 0444,
.proc_handler = &proc_dointvec,
},
+#if defined(CONFIG_X86_LOCAL_APIC)
+ {
+ .ctl_name = KERN_UNKNOWN_NMI_PANIC,
+ .procname = "unknown_nmi_panic",
+ .data = &unknown_nmi_panic,
+ .maxlen = sizeof (int),
+ .mode = 0644,
+ .proc_handler = &proc_unknown_nmi_panic,
+ },
+#endif
{ .ctl_name = 0 }
};
====
--- proc.txt.orig 2004-06-03 23:40:56.785905960 +0900
+++ proc.txt 2004-06-03 23:42:06.264343632 +0900
@@ -1109,6 +1109,20 @@
The location where the modprobe binary is located. The kernel uses this
program to load modules on demand.
+unknown_nmi_panic
+-----------------
+
+The value in this file affects behavior of handling NMI. When the value is
+non-zero, unknown NMI is trapped and then panic occurs. At that time, kernel
+debugging information is displayed on console.
+
+NMI switch that most IA32 servers have fires unknown NMI up, for example.
+If a system hangs up, try pressing the NMI switch.
+
+[NOTE]
+ This function and oprofile share a NMI callback. Therefore this function
+ cannot be enabled when oprofile is activated.
+
2.4 /proc/sys/vm - The virtual memory subsystem
-----------------------------------------------
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/