From 1a54a76d5171f3ffd89eb69f6f38d535724e3d05 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 5 Mar 2012 14:51:50 +0100 Subject: TTY: let alloc_tty_driver deduce the owner automatically Like the rest of the kernel, make a stub from alloc_tty_driver which calls __alloc_tty_driver with proper owner. This will save us one more assignment on the driver side. Also this fixes some drivers which didn't set the owner. This allowed user to remove the module from the system even though a tty from the driver is still open. Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- include/linux/tty_driver.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux/tty_driver.h') diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 5cf685086dd3..6e65493a5e6c 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -234,6 +234,7 @@ * if provided (otherwise EINVAL will be returned). */ +#include #include #include #include @@ -324,7 +325,7 @@ struct tty_driver { extern struct list_head tty_drivers; -extern struct tty_driver *alloc_tty_driver(int lines); +extern struct tty_driver *__alloc_tty_driver(int lines, struct module *owner); extern void put_tty_driver(struct tty_driver *driver); extern void tty_set_operations(struct tty_driver *driver, const struct tty_operations *op); @@ -332,6 +333,8 @@ extern struct tty_driver *tty_find_polling_driver(char *name, int *line); extern void tty_driver_kref_put(struct tty_driver *driver); +#define alloc_tty_driver(lines) __alloc_tty_driver(lines, THIS_MODULE) + static inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d) { kref_get(&d->kref); -- cgit From 87cab16beb882d3f9e61a2c0184fa7cf76de1f90 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 5 Mar 2012 14:51:51 +0100 Subject: TTY: remove minor_num from tty_driver It was added back in 2004 and never used for anything real. Remove the only assignment in the tree as well. Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- include/linux/tty_driver.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/tty_driver.h') diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 6e65493a5e6c..e064f1704e20 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -299,7 +299,6 @@ struct tty_driver { int name_base; /* offset of printed name */ int major; /* major device number */ int minor_start; /* start of minor device number */ - int minor_num; /* number of *possible* devices */ int num; /* number of devices allocated */ short type; /* type of tty driver */ short subtype; /* subtype of tty driver */ -- cgit From 26b23209c0ea5503824df60b8f218fb04b80cad0 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 5 Mar 2012 14:51:56 +0100 Subject: TTY: tty_driver, document tty->ops->shutdown limitation Note that tty->ops->shutdown is called from whatever context the user drops the last tty reference from. E.g. if one takes a reference in an ISR, tty close happens on other CPU and the final tty put is from the ISR, tty->ops->shutdown will be called from that hard irq context. We would have a problem in vt if we start using tty refcounting from other contexts than user there. It is because vt's shutdown uses mutexes. This is yet to be fixed. Signed-off-by: Jiri Slaby Reported-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- include/linux/tty_driver.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/tty_driver.h') diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index e064f1704e20..6e6dbb7447b6 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -50,6 +50,8 @@ * Note that tty_shutdown() is not called if ops->shutdown is defined. * This means one is responsible to take care of calling ops->remove (e.g. * via tty_driver_remove_tty) and releasing tty->termios. + * Note that this hook may be called from *all* the contexts where one + * uses tty refcounting (e.g. tty_port_tty_get). * * * void (*cleanup)(struct tty_struct * tty); -- cgit