diff options
| author | Chuansheng Liu <chuansheng.liu@intel.com> | 2020-01-07 00:41:16 +0000 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-01-15 11:31:33 +0100 |
| commit | 978370956d2046b19313659ce65ed12d5b996626 (patch) | |
| tree | 45889e860a424843a3bb3dd2b8e6d26e5e3551e0 | |
| parent | b3a987b0264d3ddbb24293ebff10eddfc472f653 (diff) | |
| download | linux-978370956d2046b19313659ce65ed12d5b996626.tar.bz2 | |
x86/mce/therm_throt: Do not access uninitialized therm_work
It is relatively easy to trigger the following boot splat on an Ice Lake
client platform. The call stack is like:
kernel BUG at kernel/timer/timer.c:1152!
Call Trace:
__queue_delayed_work
queue_delayed_work_on
therm_throt_process
intel_thermal_interrupt
...
The reason is that a CPU's thermal interrupt is enabled prior to
executing its hotplug onlining callback which will initialize the
throttling workqueues.
Such a race can lead to therm_throt_process() accessing an uninitialized
therm_work, leading to the above BUG at a very early bootup stage.
Therefore, unmask the thermal interrupt vector only after having setup
the workqueues completely.
[ bp: Heavily massage commit message and correct comment formatting. ]
Fixes: f6656208f04e ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200107004116.59353-1-chuansheng.liu@intel.com
| -rw-r--r-- | arch/x86/kernel/cpu/mce/therm_throt.c | 9 |
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"); |