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(+)
