intel_idle: Avoid a double free of the per-CPU data.
authorRichard Cochran <rcochran@linutronix.de>
Wed, 6 Apr 2016 21:00:53 +0000 (17:00 -0400)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 7 Apr 2016 20:10:57 +0000 (22:10 +0200)
commitca42489d9ee3262482717c83428e087322fdc39c
treee5a121d896f3800241610c64ab0eb9cd87732bb1
parente9df69ccd1322e87eee10f28036fad9e6c71f8dd
intel_idle: Avoid a double free of the per-CPU data.

The helper function, intel_idle_cpuidle_devices_uninit, frees the
globally allocated per-CPU data.  However, this function is invoked
from the hot plug notifier callback at a time when freeing that data
is not safe.

If the call to cpuidle_register_driver() should fail (say, due to lack
of memory), then the driver will free its per-CPU region.  On the
*next* CPU_ONLINE event, the driver will happily use the region again
and even free it again if the failure repeats.

This patch fixes the issue by moving the call to free_percpu() outside
of the helper function at the two call sites that actually need to
free the per-CPU data.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/idle/intel_idle.c