1. 06 3月, 2014 1 次提交
    • A
      cpufreq: use cpufreq_cpu_get() to avoid cpufreq_get() race conditions · 999976e0
      Aaron Plattner 提交于
      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.
      
      Fix this by using cpufreq_cpu_get(cpu) to look up the policy rather
      than reading it out of cpufreq_cpu_data directly.  cpufreq_cpu_get()
      takes the appropriate locks to prevent this race from happening.
      
      Since it's possible for policy to be NULL if the caller passes in an
      invalid CPU number or calls the function before cpufreq is initialized,
      delete the BUG_ON(!policy) and simply return 0.  Don't try to return
      -ENOENT because that's negative and the function returns an unsigned
      integer.
      
      References: https://bbs.archlinux.org/viewtopic.php?id=177934Signed-off-by: NAaron Plattner <aplattner@nvidia.com>
      Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
      Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      999976e0
  2. 03 3月, 2014 8 次提交
  3. 02 3月, 2014 8 次提交
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  5. 28 2月, 2014 13 次提交