mm: validate device_hotplug is held for memory hotplug
authorDan Williams <dan.j.williams@intel.com>
Fri, 24 Feb 2017 22:55:48 +0000 (14:55 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 25 Feb 2017 01:46:53 +0000 (17:46 -0800)
commit3fc21924100b13f73c734d0ce8dfcfe913fcf7a8
tree3d9f46a4936f591e5e306cf909e44fe6012efe89
parentb5d24fda9c3dce51fcb4eee459550a458eaaf1e2
mm: validate device_hotplug is held for memory hotplug

mem_hotplug_begin() assumes that it can set mem_hotplug.active_writer
and run the hotplug process without racing another thread.  Validate
this assumption with a lockdep assertion.

Link: http://lkml.kernel.org/r/148693886229.16345.1770484669403334689.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/base/core.c
include/linux/device.h
mm/memory_hotplug.c