int nmi_watchdog_tick (struct pt_regs * regs)
{
/*
* Since current_thread_info()-> is always on the stack, and we
* always switch the stack NMI-atomically, it's safe to use
* smp_processor_id().
*/
int sum, cpu = smp_processor_id(), rc = 0;
sum = irq_stat[cpu].apic_timer_irqs;
if (last_irq_sums[cpu] == sum) {
/*
* Ayiee, looks like this CPU is stuck ...
* wait a few IRQs (5 seconds) before doing the oops ...
*/
alert_counter[cpu]++;
if (alert_counter[cpu] == 30*nmi_hz)
die_nmi(regs, "NMI Watchdog detected LOCKUP");
} else {
last_irq_sums[cpu] = sum;
alert_counter[cpu] = 0;
}
/* see if the nmi watchdog went off */
if (!__get_cpu_var(wd_enabled))
return rc;
switch (nmi_watchdog) {
case NMI_LOCAL_APIC:
rc |= lapic_wd_event(nmi_hz);
break;
case NMI_IO_APIC:
/*
* don't know how to accurately check for this.
* just assume it was a watchdog timer interrupt
* This matches the old behaviour.
*/
rc = 1;
break;
}
return rc;
}
notrace __kprobes int
nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
{
/*
* Since current_thread_info()-> is always on the stack, and we
* always switch the stack NMI-atomically, it's safe to use
* smp_processor_id().
*/
unsigned int sum;
int touched = 0;
int cpu = smp_processor_id();
int rc = 0;
/* check for other users first */
if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
== NOTIFY_STOP) {
rc = 1;
touched = 1;
}
sum = get_timer_irqs(cpu);
if (__get_cpu_var(nmi_touch)) {
__get_cpu_var(nmi_touch) = 0;
touched = 1;
}
/* We can be called before check_nmi_watchdog, hence NULL check. */
if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
static DEFINE_RAW_SPINLOCK(lock); /* Serialise the printks */
raw_spin_lock(&lock);
printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
show_regs(regs);
dump_stack();
raw_spin_unlock(&lock);
cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
rc = 1;
}
/* Could check oops_in_progress here too, but it's safer not to */
if (mce_in_progress())
touched = 1;
/* if the none of the timers isn't firing, this cpu isn't doing much */
if (!touched && __get_cpu_var(last_irq_sum) == sum) {
/*
* Ayiee, looks like this CPU is stuck ...
* wait a few IRQs (5 seconds) before doing the oops ...
*/
__this_cpu_inc(alert_counter);
if (__this_cpu_read(alert_counter) == 5 * nmi_hz)
/*
* die_nmi will return ONLY if NOTIFY_STOP happens..
*/
die_nmi("BUG: NMI Watchdog detected LOCKUP",
regs, panic_on_timeout);
} else {
__get_cpu_var(last_irq_sum) = sum;
__this_cpu_write(alert_counter, 0);
}
/* see if the nmi watchdog went off */
if (!__get_cpu_var(wd_enabled))
return rc;
switch (nmi_watchdog) {
case NMI_LOCAL_APIC:
rc |= lapic_wd_event(nmi_hz);
break;
case NMI_IO_APIC:
/*
* don't know how to accurately check for this.
* just assume it was a watchdog timer interrupt
* This matches the old behaviour.
*/
rc = 1;
break;
}
return rc;
}
