x86, NMI watchdog: disable NMIs on LVT0 in case NMI watchdog is not working
Impact: change NMI watchdog detection and disabling sequence
Currently, if the NMI watchdog fails using IOAPIC method, it'll only disable
interrupts on 8259 if the timer is passing thru it. This patch disables
NMI delivery on LINT0 if the NMI watchdog initial test fails, just for safety.
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 2c005fa..13316cf 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -131,6 +131,11 @@
atomic_dec(&nmi_active);
}
+static void __acpi_nmi_disable(void *__unused)
+{
+ apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
+}
+
int __init check_nmi_watchdog(void)
{
unsigned int *prev_nmi_count;
@@ -179,8 +184,12 @@
kfree(prev_nmi_count);
return 0;
error:
- if (nmi_watchdog == NMI_IO_APIC && !timer_through_8259)
- disable_8259A_irq(0);
+ if (nmi_watchdog == NMI_IO_APIC) {
+ if (!timer_through_8259)
+ disable_8259A_irq(0);
+ on_each_cpu(__acpi_nmi_disable, NULL, 1);
+ }
+
#ifdef CONFIG_X86_32
timer_ack = 0;
#endif
@@ -285,11 +294,6 @@
on_each_cpu(__acpi_nmi_enable, NULL, 1);
}
-static void __acpi_nmi_disable(void *__unused)
-{
- apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
-}
-
/*
* Disable timer based NMIs on all CPUs:
*/