diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2013-03-11 16:44:32 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-18 16:44:01 -0700 |
| commit | b66f4fa509153ca9d313075806d5c6425dfa43c5 (patch) | |
| tree | 75ffb2d9571849938b20b15e51a361ac58d29b08 /drivers/tty | |
| parent | 25518c68b334aa977d857dd71dd53f694ffb11e8 (diff) | |
n_tty: Fully initialize ldisc before restarting buffer work
Buffer work may already be pending when the n_tty ldisc is re-opened,
eg., when setting the ldisc (via TIOCSETD ioctl) and when hanging up
the tty. Since n_tty_set_room() may restart buffer work, first ensure
the ldisc is completely initialized.
Factor n_tty_set_room() out of reset_buffer_flags() (only 2 callers)
and reorganize n_tty_open() to set termios last; buffer work will
be restarted there if necessary, after the char_map is properly
initialized.
Fixes this WARNING:
[ 549.561769] ------------[ cut here ]------------
[ 549.598755] WARNING: at drivers/tty/n_tty.c:160 n_tty_set_room+0xff/0x130()
[ 549.604058] scheduling buffer work for halted ldisc
[ 549.607741] Pid: 9417, comm: trinity-child28 Tainted: G D W 3.7.0-next-20121217-sasha-00023-g8689ef9 #219
[ 549.652580] Call Trace:
[ 549.662754] [<ffffffff81c432cf>] ? n_tty_set_room+0xff/0x130
[ 549.665458] [<ffffffff8110cae7>] warn_slowpath_common+0x87/0xb0
[ 549.668257] [<ffffffff8110cb71>] warn_slowpath_fmt+0x41/0x50
[ 549.671007] [<ffffffff81c432cf>] n_tty_set_room+0xff/0x130
[ 549.673268] [<ffffffff81c44597>] reset_buffer_flags+0x137/0x150
[ 549.675607] [<ffffffff81c45b71>] n_tty_open+0x131/0x1c0
[ 549.677699] [<ffffffff81c47824>] tty_ldisc_open.isra.5+0x54/0x70
[ 549.680147] [<ffffffff81c482bf>] tty_ldisc_hangup+0x11f/0x1e0
[ 549.682409] [<ffffffff81c3fa17>] __tty_hangup+0x137/0x440
[ 549.684634] [<ffffffff81c3fd49>] tty_vhangup+0x9/0x10
[ 549.686443] [<ffffffff81c4a42c>] pty_close+0x14c/0x160
[ 549.688446] [<ffffffff81c41225>] tty_release+0xd5/0x490
[ 549.690460] [<ffffffff8127d8a2>] __fput+0x122/0x250
[ 549.692577] [<ffffffff8127d9d9>] ____fput+0x9/0x10
[ 549.694534] [<ffffffff811348c2>] task_work_run+0xb2/0xf0
[ 549.696349] [<ffffffff81113c6d>] do_exit+0x36d/0x580
[ 549.698286] [<ffffffff8107d964>] ? syscall_trace_enter+0x24/0x2e0
[ 549.702729] [<ffffffff81113f4a>] do_group_exit+0x8a/0xc0
[ 549.706775] [<ffffffff81113f92>] sys_exit_group+0x12/0x20
[ 549.711088] [<ffffffff83cfab18>] tracesys+0xe1/0xe6
[ 549.728001] ---[ end trace 73eb41728f11f87e ]---
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/n_tty.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 0d3f715de7d..d655416087b 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -204,9 +204,8 @@ static void put_tty_queue(unsigned char c, struct n_tty_data *ldata) * Locking: tty_read_lock for read fields. */ -static void reset_buffer_flags(struct tty_struct *tty) +static void reset_buffer_flags(struct n_tty_data *ldata) { - struct n_tty_data *ldata = tty->disc_data; unsigned long flags; raw_spin_lock_irqsave(&ldata->read_lock, flags); @@ -219,7 +218,6 @@ static void reset_buffer_flags(struct tty_struct *tty) ldata->canon_head = ldata->canon_data = ldata->erasing = 0; bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); - n_tty_set_room(tty); } static void n_tty_packet_mode_flush(struct tty_struct *tty) @@ -247,7 +245,8 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty) static void n_tty_flush_buffer(struct tty_struct *tty) { - reset_buffer_flags(tty); + reset_buffer_flags(tty->disc_data); + n_tty_set_room(tty); if (tty->link) n_tty_packet_mode_flush(tty); @@ -1633,14 +1632,14 @@ static int n_tty_open(struct tty_struct *tty) goto err_free_bufs; tty->disc_data = ldata; - /* indicate buffer work may resume */ - clear_bit(TTY_LDISC_HALTED, &tty->flags); - reset_buffer_flags(tty); - tty_unthrottle(tty); + reset_buffer_flags(tty->disc_data); ldata->column = 0; - n_tty_set_termios(tty, NULL); tty->minimum_to_wake = 1; tty->closing = 0; + /* indicate buffer work may resume */ + clear_bit(TTY_LDISC_HALTED, &tty->flags); + n_tty_set_termios(tty, NULL); + tty_unthrottle(tty); return 0; err_free_bufs: |