arch/alpha, termios: implement BOTHER, IBSHIFT and termios2
authorH. Peter Anvin (Intel) <hpa@zytor.com>
Mon, 22 Oct 2018 16:19:05 +0000 (09:19 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 8 Nov 2018 12:09:30 +0000 (04:09 -0800)
commitd0ffb805b729322626639336986bc83fc2e60871
tree0aeabdf855a473fc821f87f53be51653e046ef21
parent991a25194097006ec1e0d2e0814ff920e59e3465
arch/alpha, termios: implement BOTHER, IBSHIFT and termios2

Alpha has had c_ispeed and c_ospeed, but still set speeds in c_cflags
using arbitrary flags. Because BOTHER is not defined, the general
Linux code doesn't allow setting arbitrary baud rates, and because
CBAUDEX == 0, we can have an array overrun of the baud_rate[] table in
drivers/tty/tty_baudrate.c if (c_cflags & CBAUD) == 037.

Resolve both problems by #defining BOTHER to 037 on Alpha.

However, userspace still needs to know if setting BOTHER is actually
safe given legacy kernels (does anyone actually care about that on
Alpha anymore?), so enable the TCGETS2/TCSETS*2 ioctls on Alpha, even
though they use the same structure. Define struct termios2 just for
compatibility; it is the exact same structure as struct termios. In a
future patchset, this will be cleaned up so the uapi headers are
usable from libc.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Cc: <linux-alpha@vger.kernel.org>
Cc: <linux-serial@vger.kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/alpha/include/asm/termios.h
arch/alpha/include/uapi/asm/ioctls.h
arch/alpha/include/uapi/asm/termbits.h