Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] cpufreq: use cpufreq_cpu_get to avoid cpufreq_get race conditions | Date | Thu, 06 Mar 2014 13:30:57 +0100 |
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On Wednesday, March 05, 2014 05:14:26 PM Aaron Plattner wrote: > On 03/05/14 17:23, Rafael J. Wysocki wrote: > > On Tuesday, March 04, 2014 12:42:15 PM Aaron Plattner wrote: > >> If a module calls cpufreq_get while cpufreq is initializing, it's possible for > >> it to be called after cpufreq_driver is set but before cpufreq_cpu_data is > >> written during subsys_interface_register. This happens because cpufreq_get > >> doesn't take the cpufreq_driver_lock around its use of cpufreq_cpu_data. > > > > Is this a theoretical race, or can you actually reproduce it? If so, on what > > system/driver? Or are there any bug reports related to this you can point me > > to? > > It reproduces on my Arch Linux system at home with the nvidia driver, > and there has been at least one bug report that looks like the same thing: > > https://bbs.archlinux.org/viewtopic.php?id=177934 > > I reproduced the problem with v3.13.5, then applied this change and was > able to boot successfully 10/10 times. So I guess that means you can add > > Tested-by: Aaron Plattner <aplattner@nvidia.com>
Tested-by is not needed if you're the author.
Everybody should test their patches, right? ;-)
I'll mark it for 3.13-stable and add the link above to the changelog.
Thanks!
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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