Hold console sem while creating/destroying sysfs files. Serialisation is
so far done by BKL held in tty release_dev and chrdev_open, but no other
locks are held in open path.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Aristeu Rozanski <aris@ruivo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>