From: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>
NMI for show_regs causes unknown NMI when nmi_watchdog is local APIC mode.
Because lapic_wd_event() will fail due to still running perfctr.
If NMI is for show_regs, nmi_watchdog_tick() should return 1.
On x86_32, call irq_show_regs_callback() is moved to top of the
nmi_watchdog_tick() same as x86_64.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>
---
arch/x86/kernel/nmi_32.c | 10 +++++-----
arch/x86/kernel/nmi_64.c | 9 +++++----
include/linux/sched.h | 2 +-
3 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi_32.c
index da9deb3..d1f92ca 100644
--- a/arch/x86/kernel/nmi_32.c
+++ b/arch/x86/kernel/nmi_32.c
@@ -350,10 +350,10 @@ void nmi_show_all_regs(void)
static DEFINE_RAW_SPINLOCK(nmi_print_lock);
-notrace void irq_show_regs_callback(int cpu, struct pt_regs *regs)
+notrace int irq_show_regs_callback(int cpu, struct pt_regs *regs)
{
if (!nmi_show_regs[cpu])
- return;
+ return 0;
nmi_show_regs[cpu] = 0;
spin_lock(&nmi_print_lock);
@@ -362,6 +362,7 @@ notrace void irq_show_regs_callback(int cpu, struct pt_regs *regs)
per_cpu(irq_stat, cpu).apic_timer_irqs);
show_regs(regs);
spin_unlock(&nmi_print_lock);
+ return 1;
}
notrace __kprobes int
@@ -376,8 +377,9 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
unsigned int sum;
int touched = 0;
int cpu = smp_processor_id();
- int rc=0;
+ int rc;
+ rc = irq_show_regs_callback(cpu, regs);
__profile_tick(CPU_PROFILING, regs);
/* check for other users first */
@@ -404,8 +406,6 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
sum = per_cpu(irq_stat, cpu).apic_timer_irqs +
per_cpu(irq_stat, cpu).irq0_irqs;
- irq_show_regs_callback(cpu, regs);
-
/* if the apic timer isn't firing, this cpu isn't doing much */
/* if the none of the timers isn't firing, this cpu isn't doing much */
if (!touched && last_irq_sums[cpu] == sum) {
diff --git a/arch/x86/kernel/nmi_64.c b/arch/x86/kernel/nmi_64.c
index 5d3073c..afc0317 100644
--- a/arch/x86/kernel/nmi_64.c
+++ b/arch/x86/kernel/nmi_64.c
@@ -340,10 +340,10 @@ void nmi_show_all_regs(void)
static DEFINE_RAW_SPINLOCK(nmi_print_lock);
-notrace void irq_show_regs_callback(int cpu, struct pt_regs *regs)
+notrace int irq_show_regs_callback(int cpu, struct pt_regs *regs)
{
if (!nmi_show_regs[cpu])
- return;
+ return 0;
nmi_show_regs[cpu] = 0;
spin_lock(&nmi_print_lock);
@@ -351,6 +351,7 @@ notrace void irq_show_regs_callback(int cpu, struct pt_regs *regs)
printk(KERN_WARNING "apic_timer_irqs: %d\n", read_pda(apic_timer_irqs));
show_regs(regs);
spin_unlock(&nmi_print_lock);
+ return 1;
}
notrace int __kprobes
@@ -359,9 +360,9 @@ nmi_watchdog_tick(struct pt_regs * regs, unsigned reason)
int sum;
int touched = 0;
int cpu = smp_processor_id();
- int rc = 0;
+ int rc;
- irq_show_regs_callback(cpu, regs);
+ rc = irq_show_regs_callback(cpu, regs);
__profile_tick(CPU_PROFILING, regs);
/* check for other users first */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4176f87..a37200a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -292,7 +292,7 @@ static inline void show_state(void)
}
extern void show_regs(struct pt_regs *);
-extern void irq_show_regs_callback(int cpu, struct pt_regs *regs);
+extern int irq_show_regs_callback(int cpu, struct pt_regs *regs);
/*
* TASK is a pointer to the task whose backtrace we want to see (or NULL for current
--
1.5.4.1
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