Re: [PATCH 3/4 V2] Use get_online_cpus to avoid races involving CPU hotplug

[Jean Delvare <khali@linux-fr.org>]

On Fri, 3 Aug 2012 12:35:28 -0700, Silas Boyd-Wickizer wrote:
> via_cputemp_init in drivers/hwmon/via-cputemp.c loops with
> for_each_online_cpu, adding platform_devices, then calls
> register_hotcpu_notifier.  If a CPU is offlined between the loop and
> register_hotcpu_notifier, then later onlined, via_cputemp_device_add
> will attempt to add platform devices with the same ID.  A similar race
> occurs during via_cputemp_exit, after the module calls
> unregister_hotcpu_notifier, a CPU might offline and a device will
> exist for a CPU that is offline.
> 
> This fix surrounds for_each_online_cpu and register_hotcpu_notifier
> with get_online_cpus+put_online_cpus; and surrounds
> unregister_hotcpu_notifier and device unregistering with
> get_online_cpus+put_online_cpus.
> 
> Build tested.
> 
> Signed-off-by: Silas Boyd-Wickizer <sbw@mit.edu>
> ---
>  drivers/hwmon/via-cputemp.c |    5 +++++
>  1 file changed, 5 insertions(+)
> (...)

Applied, thanks.

-- 
Jean Delvare