[PATCH 0/2] fix devm_memremap_pages() mem hotplug locking

[Dan Williams]

Ben notes that commit f931ab479dd2 "mm: fix devm_memremap_pages crash,
use mem_hotplug_{begin, done}" is incomplete and broken. Writes to
mem_hotplug.active_writer need to be coordinated under the device
hotplug lock. Otherwise, we can potentially corrupt mem_hotplug.refcount
leading to soft lockups.

---

Dan Williams (2):
      mm, devm_memremap_pages: hold device_hotplug lock over mem_hotplug_{begin,done}
      mm: validate device_hotplug is held for memory hotplug


 drivers/base/core.c    |    5 +++++
 include/linux/device.h |    1 +
 kernel/memremap.c      |    5 +++++
 mm/memory_hotplug.c    |    2 ++
 4 files changed, 13 insertions(+)