mainline inclusion
from mainline-5.4-rc1
commit 19a4ff534bb09686f53800564cb977bad2177c00
category: bugfix
bugzilla: 28332
CVE: NA

-------------------------------------------------

membarrier commands cover very different code paths if they are in
a single-threaded vs multi-threaded process. Therefore, exercise both
scenarios in the kernel selftests to increase coverage of this selftest.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-6-mathieu.desnoyers@efficios.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>
Reviewed-By: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>