Commit e287d646 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

tty: n_tty: clean up process_output_block() 



* Use guard(mutex), which results in:
  - the function can return directly when "space == 0".
  - "i" can now be "unsigned" as it is no longer abused to hold a retval
    from tty->ops->write(). Note the compared-to "nr" is already
    "unsigned".
* The end label is now dubbed "do_write" as that is what happens there.
  Unlike the uncertain "break_out" name.

Signed-off-by: default avatarJiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-8-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fdfa49a8

drivers/tty/n_tty.c

+11 −16
Original line number Diff line number Diff line
@@ -519,17 +519,15 @@ static ssize_t process_output_block(struct tty_struct *tty, 
				    const u8 *buf, unsigned int nr)

{

	struct n_tty_data *ldata = tty->disc_data;

	unsigned int space;

	int i;

	unsigned int space, i;

	const u8 *cp;



	mutex_lock(&ldata->output_lock);

	guard(mutex)(&ldata->output_lock);



	space = tty_write_room(tty);

	if (space == 0) {

		mutex_unlock(&ldata->output_lock);

	if (space == 0)

		return 0;

	}



	if (nr > space)

		nr = space;
@@ -541,18 +539,18 @@ static ssize_t process_output_block(struct tty_struct *tty, 
			if (O_ONLRET(tty))

				ldata->column = 0;

			if (O_ONLCR(tty))

				goto break_out;

				goto do_write;

			ldata->canon_column = ldata->column;

			break;

		case '\r':

			if (O_ONOCR(tty) && ldata->column == 0)

				goto break_out;

				goto do_write;

			if (O_OCRNL(tty))

				goto break_out;

				goto do_write;

			ldata->canon_column = ldata->column = 0;

			break;

		case '\t':

			goto break_out;

			goto do_write;

		case '\b':

			if (ldata->column > 0)

				ldata->column--;
@@ -560,18 +558,15 @@ static ssize_t process_output_block(struct tty_struct *tty, 
		default:

			if (!iscntrl(c)) {

				if (O_OLCUC(tty))

					goto break_out;

					goto do_write;

				if (!is_continuation(c, tty))

					ldata->column++;

			}

			break;

		}

	}

break_out:

	i = tty->ops->write(tty, buf, i);



	mutex_unlock(&ldata->output_lock);

	return i;

do_write:

	return tty->ops->write(tty, buf, i);

}



static int n_tty_process_echo_ops(struct tty_struct *tty, size_t *tail,