Commit b91939f5 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

TTY: n_tty, simplify read_buf+echo_buf allocation 



ldisc->open and close are called only once and cannot cross. So the
tests in open and close are superfluous. Remove them. (But leave sets
to NULL to ensure there is not a bug somewhere.)

And when the tests are gone, handle properly failures in open. We
leaked read_buf if allocation of echo_buf failed before. Now this is
not the case anymore.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Acked-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f327b340

drivers/tty/n_tty.c

+13 −18
Original line number Diff line number Diff line
@@ -1561,15 +1561,11 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) 
static void n_tty_close(struct tty_struct *tty)

{

	n_tty_flush_buffer(tty);

	if (tty->read_buf) {

	kfree(tty->read_buf);

		tty->read_buf = NULL;

	}

	if (tty->echo_buf) {

	kfree(tty->echo_buf);

	tty->read_buf = NULL;

	tty->echo_buf = NULL;

}

}



/**

 *	n_tty_open		-	open an ldisc
@@ -1587,17 +1583,11 @@ static int n_tty_open(struct tty_struct *tty) 
		return -EINVAL;



	/* These are ugly. Currently a malloc failure here can panic */

	if (!tty->read_buf) {

	tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);

		if (!tty->read_buf)

			return -ENOMEM;

	}

	if (!tty->echo_buf) {

	tty->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);

	if (!tty->read_buf || !tty->echo_buf)

		goto err_free_bufs;



		if (!tty->echo_buf)

			return -ENOMEM;

	}

	reset_buffer_flags(tty);

	tty_unthrottle(tty);

	tty->column = 0;
@@ -1605,6 +1595,11 @@ static int n_tty_open(struct tty_struct *tty) 
	tty->minimum_to_wake = 1;

	tty->closing = 0;

	return 0;

err_free_bufs:

	kfree(tty->read_buf);

	kfree(tty->echo_buf);



	return -ENOMEM;

}



static inline int input_available_p(struct tty_struct *tty, int amt)

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