[APPLIED] Re: [Maverick] [PATCH 1/1] x86, hwmon: Fix unsafe smp_processor_id() in thermal_throttle_add_dev

[Leann Ogasawara]

Applied to Maverick linux master.

Thanks,
Leann

On Tue, 2010-09-14 at 11:36 -0700, Leann Ogasawara wrote:
> Hi All,
> 
> We'd applied a set of patches in Maverick [1] to provide Package Thermal
> Status and Power Limit Notification which is a new feature for Intel's
> Sandy Bridge processor.  The following patch is an upstream cherry-pick
> to resolve "BUG: using smp_processor_id() in preemptible" errors
> introduced by this patch set.  Proposing for Maverick.
> 
> Thanks,
> Leann
> 
> [1] https://lists.ubuntu.com/archives/kernel-team/2010-August/012487.html
> 
> From a2ba1e647812788c0e87965d717a54907912ceb1 Mon Sep 17 00:00:00 2001
> From: Sergey Senozhatsky <sergey.senozhatsky at gmail.com>
> Date: Fri, 20 Aug 2010 10:36:34 +0300
> Subject: [PATCH] x86, hwmon: Fix unsafe smp_processor_id() in thermal_throttle_add_dev
> 
> BugLink: http://bugs.launchpad.net/bugs/601073
> 
> 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 at gmail.com>
> LKML-Reference: <20100820073634.GB5209 at swordfish.minsk.epam.com>
> Cc: Fenghua Yu <fenghua.yu at intel.com>
> Cc: Joerg Roedel <Joerg.Roedel at amd.com>
> Cc: Maciej Rutecki <maciej.rutecki at gmail.com>
> Signed-off-by: H. Peter Anvin <hpa at zytor.com>
> (cherry picked from commit 51e3c1b558b31b11bf5fc66d3c6f5adacf3573f7)
> 
> Signed-off-by: Leann Ogasawara <leann.ogasawara at canonical.com>
> ---
>  arch/x86/kernel/cpu/mcheck/therm_throt.c |    9 +++++----
>  1 files changed, 5 insertions(+), 4 deletions(-)
> 
> 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
> -- 
> 1.7.1
> 
> 
> 
>