From c81622ac4282b0183e738e192c91fabe4a782715 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Fri, 16 Jan 2015 15:22:14 -0500 Subject: [PATCH] pty: Fix overlimit memory use The pty_space() computation is broken; the space already consumed in the tty buffer is not accounted for. Use tty_buffer_set_limit(), which enforces the limit automatically. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/pty.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 6e1f1505f04e..f882ac81b93a 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -87,19 +87,6 @@ static void pty_unthrottle(struct tty_struct *tty) set_bit(TTY_THROTTLED, &tty->flags); } -/** - * pty_space - report space left for writing - * @to: tty we are writing into - * - * Limit the buffer space used by ptys to 8k. - */ - -static int pty_space(struct tty_struct *to) -{ - int n = tty_buffer_space_avail(to->port); - return min(n, 8192); -} - /** * pty_write - write to a pty * @tty: the tty we write from @@ -141,7 +128,7 @@ static int pty_write_room(struct tty_struct *tty) { if (tty->stopped) return 0; - return pty_space(tty->link); + return tty_buffer_space_avail(tty->link->port); } /** @@ -432,6 +419,8 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty, o_tty->link = tty; tty_port_init(ports[0]); tty_port_init(ports[1]); + tty_buffer_set_limit(ports[0], 8192); + tty_buffer_set_limit(ports[1], 8192); o_tty->port = ports[0]; tty->port = ports[1]; o_tty->port->itty = o_tty; -- 2.45.2