Merge branch 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 RAS fix from Ingo Molnar:
 "Fix a thermal throttling race that can result in easy to trigger boot
  crashes on certain Ice Lake platforms"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce/therm_throt: Do not access uninitialized therm_work

1 files changed, 5 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/mce/therm_throt.c b/arch/x86/kernel/cpu/mce/therm_throt.c
index b38010b541d6..6c3e1c92f183 100644
--- a/arch/x86/kernel/cpu/mce/therm_throt.c
+++ b/arch/x86/kernel/cpu/mce/therm_throt.c
@@ -467,6 +467,7 @@ static int thermal_throttle_online(unsigned int cpu)
 {
 	struct thermal_state *state = &per_cpu(thermal_state, cpu);
 	struct device *dev = get_cpu_device(cpu);
+	u32 l;
 
 	state->package_throttle.level = PACKAGE_LEVEL;
 	state->core_throttle.level = CORE_LEVEL;
@@ -474,6 +475,10 @@ static int thermal_throttle_online(unsigned int cpu)
 	INIT_DELAYED_WORK(&state->package_throttle.therm_work, throttle_active_work);
 	INIT_DELAYED_WORK(&state->core_throttle.therm_work, throttle_active_work);
 
+	/* Unmask the thermal vector after the above workqueues are initialized. */
+	l = apic_read(APIC_LVTTHMR);
+	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
+
 	return thermal_throttle_add_dev(dev, cpu);
 }
 
@@ -722,10 +727,6 @@ void intel_init_thermal(struct cpuinfo_x86 *c)
 	rdmsr(MSR_IA32_MISC_ENABLE, l, h);
 	wrmsr(MSR_IA32_MISC_ENABLE, l | MSR_IA32_MISC_ENABLE_TM1, h);
 
-	/* Unmask the thermal vector: */
-	l = apic_read(APIC_LVTTHMR);
-	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
-
 	pr_info_once("CPU0: Thermal monitoring enabled (%s)\n",
 		      tm2 ? "TM2" : "TM1");