From 51e3c1b558b31b11bf5fc66d3c6f5adacf3573f7 Mon Sep 17 00:00:00 2001
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Date: Fri, 20 Aug 2010 10:36:34 +0300
Subject: x86, hwmon: Fix unsafe smp_processor_id() in thermal_throttle_add_dev
Fix BUG: using smp_processor_id() in preemptible thermal_throttle_add_dev.
We know the cpu number when calling thermal_throttle_add_dev, so we can
remove smp_processor_id call in thermal_throttle_add_dev by supplying
the cpu number as argument.
This should resolve kernel bugzilla 16615/16629.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
LKML-Reference: <20100820073634.GB5209@swordfish.minsk.epam.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Joerg Roedel <Joerg.Roedel@amd.com>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
arch/x86/kernel/cpu/mcheck/therm_throt.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
(limited to 'arch/x86/kernel')
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index c2a8b26..d9368ee 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -202,10 +202,11 @@ static int therm_throt_process(bool new_event, int event, int level)
#ifdef CONFIG_SYSFS
/* Add/Remove thermal_throttle interface for CPU device: */
-static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
+static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev,
+ unsigned int cpu)
{
int err;
- struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
+ struct cpuinfo_x86 *c = &cpu_data(cpu);
err = sysfs_create_group(&sys_dev->kobj, &thermal_attr_group);
if (err)
@@ -251,7 +252,7 @@ thermal_throttle_cpu_callback(struct notifier_block *nfb,
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
mutex_lock(&therm_cpu_lock);
- err = thermal_throttle_add_dev(sys_dev);
+ err = thermal_throttle_add_dev(sys_dev, cpu);
mutex_unlock(&therm_cpu_lock);
WARN_ON(err);
break;
@@ -287,7 +288,7 @@ static __init int thermal_throttle_init_device(void)
#endif
/* connect live CPUs to sysfs */
for_each_online_cpu(cpu) {
- err = thermal_throttle_add_dev(get_cpu_sysdev(cpu));
+ err = thermal_throttle_add_dev(get_cpu_sysdev(cpu), cpu);
WARN_ON(err);
}
#ifdef CONFIG_HOTPLUG_CPU
--
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