tree 5ae924ca46720ffad8feba6ac797e0beeef46236
parent 68baf692c435339e6295cb470ea5545cbc28160e
author Tyrel Datwyler <tyreld@linux.vnet.ibm.com> 1492475079 -0400
committer Michael Ellerman <mpe@ellerman.id.au> 1493043899 +1000

powerpc/sysfs: Fix reference leak of cpu device_nodes present at boot

For CPUs present at boot each logical CPU acquires a reference to the
associated device node of the core. This happens in register_cpu() which
is called by topology_init(). The result of this is that we end up with
a reference held by each thread of the core. However, these references
are never freed if the CPU core is DLPAR removed.

This patch fixes the reference leaks by acquiring and releasing the references
in the CPU hotplug callbacks un/register_cpu_online(). With this patch symmetric
reference counting is observed with both CPUs present at boot, and those DLPAR
added after boot.

Fixes: f86e4718f24b ("driver/core: cpu: initialize of_node in cpu's device struture")
Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>