Commits
Al Viro committed a555ad450f9
whack-a-mole: no need to set_fs(USER_DS) in {start,flush}_thread()
flush_old_exec() has already done that. Back on 2011 a bunch of
instances like that had been kicked out, but that hadn't taken
care of then-out-of-tree architectures, obviously, and they served
as reinfection vector...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>