tree 3256cb7ea6954f28b0bb3ccee2db570e3d0ff762
parent e9c0748b687aa70179a9e6d8ffc24b2874fe350b
author Thomas Gleixner <tglx@linutronix.de> 1260455710 +0100
committer Thomas Gleixner <tglx@linutronix.de> 1260523688 +0100

clockevents: Prevent clockevent_devices list corruption on cpu hotplug

Xiaotian Feng triggered a list corruption in the clock events list on
CPU hotplug and debugged the root cause.

If a CPU registers more than one per cpu clock event device, then only
the active clock event device is removed on CPU_DEAD. The unused
devices are kept in the clock events device list.

On CPU up the clock event devices are registered again, which means
that we list_add an already enqueued list_head. That results in list
corruption.

Resolve this by removing all devices which are associated to the dead
CPU on CPU_DEAD.

Reported-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Xiaotian Feng <dfeng@redhat.com>
Cc: stable@kernel.org