diff options
| author | Peter Hurley | 2013-03-11 21:44:38 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2013-03-19 00:46:30 +0100 |
| commit | fc575ee6eadbcac757e3216e230b6fab1ba5b140 (patch) | |
| tree | e01260de659705bbece162866d3abbbda9a69b22 /drivers/tty/tty_ldisc.c | |
| parent | tty: Bracket ldisc release with TTY_DEBUG_HANGUP messages (diff) | |
| download | kernel-qcow2-linux-fc575ee6eadbcac757e3216e230b6fab1ba5b140.tar.gz kernel-qcow2-linux-fc575ee6eadbcac757e3216e230b6fab1ba5b140.tar.xz kernel-qcow2-linux-fc575ee6eadbcac757e3216e230b6fab1ba5b140.zip | |
tty: Add ldisc hangup debug messages
Expected typical debug log:
[ 582.721965] tty_open: opening pts3...
[ 582.721970] tty_open: opening pts3...
[ 582.721977] tty_release: pts3 (tty count=3)...
[ 582.721980] tty_release: ptm3 (tty count=1)...
[ 582.722015] pts3 vhangup...
[ 582.722020] tty_ldisc_hangup: pts3: closing ldisc: ffff88007a920540
[ 582.724128] tty_release: pts3 (tty count=2)...
[ 582.724217] tty_ldisc_hangup: pts3: re-opened ldisc: ffff88007a920580
[ 582.724221] tty_release: ptm3: final close
[ 582.724234] tty_ldisc_release: ptm3: closing ldisc: ffff88007a920a80
[ 582.724238] tty_ldisc_release: ptm3: ldisc closed
[ 582.724241] tty_release: ptm3: freeing structure...
[ 582.724741] tty_open: opening pts3...
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_ldisc.c')
| -rw-r--r-- | drivers/tty/tty_ldisc.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 0030d556b9b3..328ff5b544a5 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -20,6 +20,17 @@ #include <linux/uaccess.h> #include <linux/ratelimit.h> +#undef LDISC_DEBUG_HANGUP + +#ifdef LDISC_DEBUG_HANGUP +#define tty_ldisc_debug(tty, f, args...) ({ \ + char __b[64]; \ + printk(KERN_DEBUG "%s: %s: " f, __func__, tty_name(tty, __b), ##args); \ +}) +#else +#define tty_ldisc_debug(tty, f, args...) +#endif + /* * This guards the refcounted line discipline lists. The lock * must be taken with irqs off because there are hangup path @@ -822,6 +833,8 @@ void tty_ldisc_hangup(struct tty_struct *tty) int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS; int err = 0; + tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc); + /* * FIXME! What are the locking issues here? This may me overdoing * things... This question is especially important now that we've @@ -878,6 +891,8 @@ void tty_ldisc_hangup(struct tty_struct *tty) mutex_unlock(&tty->ldisc_mutex); if (reset) tty_reset_termios(tty); + + tty_ldisc_debug(tty, "re-opened ldisc: %p\n", tty->ldisc); } /** @@ -944,6 +959,8 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty) * it does not race with the set_ldisc code path. */ + tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc); + tty_ldisc_halt(tty, o_tty, MAX_SCHEDULE_TIMEOUT); tty_lock_pair(tty, o_tty); @@ -955,6 +972,8 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty) tty_unlock_pair(tty, o_tty); /* And the memory resources remaining (buffers, termios) will be disposed of when the kref hits zero */ + + tty_ldisc_debug(tty, "ldisc closed\n"); } /** |