diff options
Diffstat (limited to 'drivers/tty/n_tty.c')
| -rw-r--r-- | drivers/tty/n_tty.c | 34 |
1 files changed, 17 insertions, 17 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index d4d71350a71d..25aaf1afa221 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -113,6 +113,7 @@ struct n_tty_data { /* consumer-published */ size_t read_tail; + size_t line_start; /* protected by output lock */ unsigned int column; @@ -337,6 +338,7 @@ static void reset_buffer_flags(struct n_tty_data *ldata) { ldata->read_head = ldata->canon_head = ldata->read_tail = 0; ldata->echo_head = ldata->echo_tail = ldata->echo_commit = 0; + ldata->line_start = 0; ldata->erasing = 0; bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); @@ -1396,8 +1398,6 @@ send_signal: if (c == EOF_CHAR(tty)) { if (read_cnt(ldata) >= N_TTY_BUF_SIZE) return; - if (ldata->canon_head != ldata->read_head) - set_bit(TTY_PUSH, &tty->flags); c = __DISABLED_CHAR; goto handle_newline; } @@ -1604,6 +1604,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) canon_change = (old->c_lflag ^ tty->termios.c_lflag) & ICANON; if (canon_change) { bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); + ldata->line_start = 0; ldata->canon_head = ldata->read_tail; ldata->erasing = 0; ldata->lnext = 0; @@ -1837,6 +1838,7 @@ static int canon_copy_from_read_buf(struct tty_struct *tty, size_t eol; size_t tail; int ret, found = 0; + bool eof_push = 0; /* N.B. avoid overrun if nr == 0 */ n = min(*nr, read_cnt(ldata)); @@ -1863,8 +1865,10 @@ static int canon_copy_from_read_buf(struct tty_struct *tty, n = (found + eol + size) & (N_TTY_BUF_SIZE - 1); c = n; - if (found && read_buf(ldata, eol) == __DISABLED_CHAR) + if (found && read_buf(ldata, eol) == __DISABLED_CHAR) { n--; + eof_push = !n && ldata->read_tail != ldata->line_start; + } n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu size:%zu more:%zu\n", __func__, eol, found, n, c, size, more); @@ -1887,9 +1891,11 @@ static int canon_copy_from_read_buf(struct tty_struct *tty, smp_mb__after_clear_bit(); ldata->read_tail += c; - if (found) + if (found) { + ldata->line_start = ldata->read_tail; tty_audit_push(tty); - return 0; + } + return eof_push ? -EAGAIN : 0; } extern ssize_t redirected_tty_write(struct file *, const char __user *, @@ -1964,12 +1970,10 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, int c; int minimum, time; ssize_t retval = 0; - ssize_t size; long timeout; unsigned long flags; int packet; -do_it_again: c = job_control(tty, file); if (c < 0) return c; @@ -2076,7 +2080,10 @@ do_it_again: if (ldata->icanon && !L_EXTPROC(tty)) { retval = canon_copy_from_read_buf(tty, &b, &nr); - if (retval) + if (retval == -EAGAIN) { + retval = 0; + continue; + } else if (retval) break; } else { int uncopied; @@ -2104,15 +2111,8 @@ do_it_again: ldata->minimum_to_wake = minimum; __set_current_state(TASK_RUNNING); - size = b - buf; - if (size) { - retval = size; - if (nr) - clear_bit(TTY_PUSH, &tty->flags); - } else if (test_and_clear_bit(TTY_PUSH, &tty->flags)) { - up_read(&tty->termios_rwsem); - goto do_it_again; - } + if (b - buf) + retval = b - buf; n_tty_set_room(tty); up_read(&tty->termios_rwsem); |