From 6716671d8c1c07a8072098764d1b7cbfef7412ad Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 23 Mar 2011 10:48:35 +0100 Subject: [PATCH 1/1] TTY: introduce deinit helpers for proper ldisc shutdown Introduce deinitialize_tty_struct which should be called after initialize_tty_struct and before successfull tty_ldisc_setup. It calls tty_ldisc_deinit which is opposite of tty_ldisc_init. It only puts a reference to ldisc and assigns NULL to tty->ldisc. It will be used to shut down ldisc when tty_release cannot be called yet. Signed-off-by: Jiri Slaby Cc: Alan Cox Cc: Julian Anastasov Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 14 ++++++++++++++ drivers/tty/tty_ldisc.c | 13 +++++++++++++ include/linux/tty.h | 2 ++ 3 files changed, 29 insertions(+) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 026bf2f6f5f2..f5dd23520fe3 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2886,6 +2886,20 @@ void initialize_tty_struct(struct tty_struct *tty, tty->dev = tty_get_device(tty); } +/** + * deinitialize_tty_struct + * @tty: tty to deinitialize + * + * This subroutine deinitializes a tty structure that has been newly + * allocated but tty_release cannot be called on that yet. + * + * Locking: none - tty in question must not be exposed at this point + */ +void deinitialize_tty_struct(struct tty_struct *tty) +{ + tty_ldisc_deinit(tty); +} + /** * tty_put_char - write one character to a tty * @tty: tty diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index e19e13647116..5d01d32e2cf0 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -956,6 +956,19 @@ void tty_ldisc_init(struct tty_struct *tty) tty_ldisc_assign(tty, ld); } +/** + * tty_ldisc_init - ldisc cleanup for new tty + * @tty: tty that was allocated recently + * + * The tty structure must not becompletely set up (tty_ldisc_setup) when + * this call is made. + */ +void tty_ldisc_deinit(struct tty_struct *tty) +{ + put_ldisc(tty->ldisc); + tty_ldisc_assign(tty, NULL); +} + void tty_ldisc_begin(void) { /* Setup the default TTY line discipline. */ diff --git a/include/linux/tty.h b/include/linux/tty.h index 9f469c700550..4db4ca79f895 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -472,6 +472,7 @@ extern int tty_add_file(struct tty_struct *tty, struct file *file); extern void free_tty_struct(struct tty_struct *tty); extern void initialize_tty_struct(struct tty_struct *tty, struct tty_driver *driver, int idx); +extern void deinitialize_tty_struct(struct tty_struct *tty); extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, int first_ok); extern int tty_release(struct inode *inode, struct file *filp); @@ -525,6 +526,7 @@ extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty); extern void tty_ldisc_init(struct tty_struct *tty); +extern void tty_ldisc_deinit(struct tty_struct *tty); extern void tty_ldisc_begin(void); /* This last one is just for the tty layer internals and shouldn't be used elsewhere */ extern void tty_ldisc_enable(struct tty_struct *tty); -- 2.25.1