Re: [PATCH 0/4 V2] Use get_online_cpus to avoid races involving CPU hotplug

[Silas Boyd-Wickizer <sbw@mit.edu>]

Hi Rusty,

I used libsparse and kernel source annotations to check that code uses
for_each_online_cpu in contexts with hotplug disabled
(e.g. get_online_cpus(), preempt_disable, ..).  I compiled with an x86
64-bit allyesconfig, so I missed other architecture specific usages.
The checker code isn't great and the results still require some manual
inspection for weeding out false positives, etc:

  http://pdos.csail.mit.edu/~sbw/online-checker/

Silas

On Thu, Aug 30, 2012 at 06:02:11AM +0930, Rusty Russell wrote:
> Silas Boyd-Wickizer <sbw@mit.edu> writes:
> 
> > Hello,
> >
> > This is the second version of the patches to fix races described in:
> >
> >   https://groups.google.com/forum/?fromgroups#!topic/linux.kernel/iSUDr94Qehc
> >
> > The changes in this version are:
> >
> >   * fix commit log typo;
> >   * prevent a race in via_cputemp_exit;
> >   * and a new patch that prevents races during init/exit in
> >     drivers/hwmon/coretemp.c.
> 
> Hi Silas,
> 
>         Good work! How did you find these?
> 
> Cheers,
> Rusty.
>