diff options
Diffstat (limited to 'drivers/tty/pty.c')
-rw-r--r-- | drivers/tty/pty.c | 234 |
1 files changed, 122 insertions, 112 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 5505ffc91da..2bace847eb3 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -47,6 +47,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp) wake_up_interruptible(&tty->read_wait); wake_up_interruptible(&tty->write_wait); tty->packet = 0; + /* Review - krefs on tty_link ?? */ if (!tty->link) return; tty->link->packet = 0; @@ -62,9 +63,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp) mutex_unlock(&devpts_mutex); } #endif - tty_unlock(); + tty_unlock(tty); tty_vhangup(tty->link); - tty_lock(); + tty_lock(tty); } } @@ -231,8 +232,8 @@ out: static void pty_set_termios(struct tty_struct *tty, struct ktermios *old_termios) { - tty->termios->c_cflag &= ~(CSIZE | PARENB); - tty->termios->c_cflag |= (CS8 | CREAD); + tty->termios.c_cflag &= ~(CSIZE | PARENB); + tty->termios.c_cflag |= (CS8 | CREAD); } /** @@ -282,60 +283,110 @@ done: return 0; } -/* Traditional BSD devices */ -#ifdef CONFIG_LEGACY_PTYS - -static int pty_install(struct tty_driver *driver, struct tty_struct *tty) +/** + * pty_common_install - set up the pty pair + * @driver: the pty driver + * @tty: the tty being instantiated + * @bool: legacy, true if this is BSD style + * + * Perform the initial set up for the tty/pty pair. Called from the + * tty layer when the port is first opened. + * + * Locking: the caller must hold the tty_mutex + */ +static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty, + bool legacy) { struct tty_struct *o_tty; + struct tty_port *ports[2]; int idx = tty->index; - int retval; + int retval = -ENOMEM; o_tty = alloc_tty_struct(); if (!o_tty) - return -ENOMEM; + goto err; + ports[0] = kmalloc(sizeof **ports, GFP_KERNEL); + ports[1] = kmalloc(sizeof **ports, GFP_KERNEL); + if (!ports[0] || !ports[1]) + goto err_free_tty; if (!try_module_get(driver->other->owner)) { /* This cannot in fact currently happen */ - retval = -ENOMEM; goto err_free_tty; } initialize_tty_struct(o_tty, driver->other, idx); - /* We always use new tty termios data so we can do this - the easy way .. */ - retval = tty_init_termios(tty); - if (retval) - goto err_deinit_tty; - - retval = tty_init_termios(o_tty); - if (retval) - goto err_free_termios; + if (legacy) { + /* We always use new tty termios data so we can do this + the easy way .. */ + retval = tty_init_termios(tty); + if (retval) + goto err_deinit_tty; + + retval = tty_init_termios(o_tty); + if (retval) + goto err_free_termios; + + driver->other->ttys[idx] = o_tty; + driver->ttys[idx] = tty; + } else { + memset(&tty->termios_locked, 0, sizeof(tty->termios_locked)); + tty->termios = driver->init_termios; + memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked)); + o_tty->termios = driver->other->init_termios; + } /* * Everything allocated ... set up the o_tty structure. */ - driver->other->ttys[idx] = o_tty; tty_driver_kref_get(driver->other); if (driver->subtype == PTY_TYPE_MASTER) o_tty->count++; /* Establish the links in both directions */ tty->link = o_tty; o_tty->link = tty; + tty_port_init(ports[0]); + tty_port_init(ports[1]); + o_tty->port = ports[0]; + tty->port = ports[1]; tty_driver_kref_get(driver); tty->count++; - driver->ttys[idx] = tty; return 0; err_free_termios: - tty_free_termios(tty); + if (legacy) + tty_free_termios(tty); err_deinit_tty: deinitialize_tty_struct(o_tty); module_put(o_tty->driver->owner); err_free_tty: + kfree(ports[0]); + kfree(ports[1]); free_tty_struct(o_tty); +err: return retval; } +static void pty_cleanup(struct tty_struct *tty) +{ + kfree(tty->port); +} + +/* Traditional BSD devices */ +#ifdef CONFIG_LEGACY_PTYS + +static int pty_install(struct tty_driver *driver, struct tty_struct *tty) +{ + return pty_common_install(driver, tty, true); +} + +static void pty_remove(struct tty_driver *driver, struct tty_struct *tty) +{ + struct tty_struct *pair = tty->link; + driver->ttys[tty->index] = NULL; + if (pair) + pair->driver->ttys[pair->index] = NULL; +} + static int pty_bsd_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) { @@ -366,7 +417,9 @@ static const struct tty_operations master_pty_ops_bsd = { .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, .ioctl = pty_bsd_ioctl, - .resize = pty_resize + .cleanup = pty_cleanup, + .resize = pty_resize, + .remove = pty_remove }; static const struct tty_operations slave_pty_ops_bsd = { @@ -379,7 +432,9 @@ static const struct tty_operations slave_pty_ops_bsd = { .chars_in_buffer = pty_chars_in_buffer, .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, - .resize = pty_resize + .cleanup = pty_cleanup, + .resize = pty_resize, + .remove = pty_remove }; static void __init legacy_pty_init(void) @@ -389,12 +444,18 @@ static void __init legacy_pty_init(void) if (legacy_count <= 0) return; - pty_driver = alloc_tty_driver(legacy_count); - if (!pty_driver) + pty_driver = tty_alloc_driver(legacy_count, + TTY_DRIVER_RESET_TERMIOS | + TTY_DRIVER_REAL_RAW | + TTY_DRIVER_DYNAMIC_ALLOC); + if (IS_ERR(pty_driver)) panic("Couldn't allocate pty driver"); - pty_slave_driver = alloc_tty_driver(legacy_count); - if (!pty_slave_driver) + pty_slave_driver = tty_alloc_driver(legacy_count, + TTY_DRIVER_RESET_TERMIOS | + TTY_DRIVER_REAL_RAW | + TTY_DRIVER_DYNAMIC_ALLOC); + if (IS_ERR(pty_slave_driver)) panic("Couldn't allocate pty slave driver"); pty_driver->driver_name = "pty_master"; @@ -410,7 +471,6 @@ static void __init legacy_pty_init(void) pty_driver->init_termios.c_lflag = 0; pty_driver->init_termios.c_ispeed = 38400; pty_driver->init_termios.c_ospeed = 38400; - pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; pty_driver->other = pty_slave_driver; tty_set_operations(pty_driver, &master_pty_ops_bsd); @@ -424,8 +484,6 @@ static void __init legacy_pty_init(void) pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; pty_slave_driver->init_termios.c_ispeed = 38400; pty_slave_driver->init_termios.c_ospeed = 38400; - pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | - TTY_DRIVER_REAL_RAW; pty_slave_driver->other = pty_driver; tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); @@ -497,78 +555,22 @@ static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, return tty; } -static void pty_unix98_shutdown(struct tty_struct *tty) -{ - tty_driver_remove_tty(tty->driver, tty); - /* We have our own method as we don't use the tty index */ - kfree(tty->termios); -} - /* We have no need to install and remove our tty objects as devpts does all the work for us */ static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) { - struct tty_struct *o_tty; - int idx = tty->index; - - o_tty = alloc_tty_struct(); - if (!o_tty) - return -ENOMEM; - if (!try_module_get(driver->other->owner)) { - /* This cannot in fact currently happen */ - goto err_free_tty; - } - initialize_tty_struct(o_tty, driver->other, idx); - - tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); - if (tty->termios == NULL) - goto err_free_mem; - *tty->termios = driver->init_termios; - tty->termios_locked = tty->termios + 1; - - o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); - if (o_tty->termios == NULL) - goto err_free_mem; - *o_tty->termios = driver->other->init_termios; - o_tty->termios_locked = o_tty->termios + 1; - - tty_driver_kref_get(driver->other); - if (driver->subtype == PTY_TYPE_MASTER) - o_tty->count++; - /* Establish the links in both directions */ - tty->link = o_tty; - o_tty->link = tty; - /* - * All structures have been allocated, so now we install them. - * Failures after this point use release_tty to clean up, so - * there's no need to null out the local pointers. - */ - tty_driver_kref_get(driver); - tty->count++; - return 0; -err_free_mem: - deinitialize_tty_struct(o_tty); - kfree(o_tty->termios); - kfree(tty->termios); - module_put(o_tty->driver->owner); -err_free_tty: - free_tty_struct(o_tty); - return -ENOMEM; -} - -static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) -{ + return pty_common_install(driver, tty, false); } -static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) +static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) { } static const struct tty_operations ptm_unix98_ops = { .lookup = ptm_unix98_lookup, .install = pty_unix98_install, - .remove = ptm_unix98_remove, + .remove = pty_unix98_remove, .open = pty_open, .close = pty_close, .write = pty_write, @@ -578,14 +580,14 @@ static const struct tty_operations ptm_unix98_ops = { .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, .ioctl = pty_unix98_ioctl, - .shutdown = pty_unix98_shutdown, - .resize = pty_resize + .resize = pty_resize, + .cleanup = pty_cleanup }; static const struct tty_operations pty_unix98_ops = { .lookup = pts_unix98_lookup, .install = pty_unix98_install, - .remove = pts_unix98_remove, + .remove = pty_unix98_remove, .open = pty_open, .close = pty_close, .write = pty_write, @@ -594,7 +596,7 @@ static const struct tty_operations pty_unix98_ops = { .chars_in_buffer = pty_chars_in_buffer, .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, - .shutdown = pty_unix98_shutdown + .cleanup = pty_cleanup, }; /** @@ -622,26 +624,27 @@ static int ptmx_open(struct inode *inode, struct file *filp) return retval; /* find a device that is not in use. */ - tty_lock(); + mutex_lock(&devpts_mutex); index = devpts_new_index(inode); - tty_unlock(); if (index < 0) { retval = index; goto err_file; } + mutex_unlock(&devpts_mutex); + mutex_lock(&tty_mutex); - mutex_lock(&devpts_mutex); tty = tty_init_dev(ptm_driver, index); - mutex_unlock(&devpts_mutex); - tty_lock(); - mutex_unlock(&tty_mutex); if (IS_ERR(tty)) { retval = PTR_ERR(tty); goto out; } + /* The tty returned here is locked so we can safely + drop the mutex */ + mutex_unlock(&tty_mutex); + set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ tty_add_file(tty, filp); @@ -654,16 +657,17 @@ static int ptmx_open(struct inode *inode, struct file *filp) if (retval) goto err_release; - tty_unlock(); + tty_unlock(tty); return 0; err_release: - tty_unlock(); + tty_unlock(tty); tty_release(inode, filp); return retval; out: + mutex_unlock(&tty_mutex); devpts_kill_index(inode, index); - tty_unlock(); err_file: + mutex_unlock(&devpts_mutex); tty_free_file(filp); return retval; } @@ -672,11 +676,21 @@ static struct file_operations ptmx_fops; static void __init unix98_pty_init(void) { - ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); - if (!ptm_driver) + ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX, + TTY_DRIVER_RESET_TERMIOS | + TTY_DRIVER_REAL_RAW | + TTY_DRIVER_DYNAMIC_DEV | + TTY_DRIVER_DEVPTS_MEM | + TTY_DRIVER_DYNAMIC_ALLOC); + if (IS_ERR(ptm_driver)) panic("Couldn't allocate Unix98 ptm driver"); - pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); - if (!pts_driver) + pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX, + TTY_DRIVER_RESET_TERMIOS | + TTY_DRIVER_REAL_RAW | + TTY_DRIVER_DYNAMIC_DEV | + TTY_DRIVER_DEVPTS_MEM | + TTY_DRIVER_DYNAMIC_ALLOC); + if (IS_ERR(pts_driver)) panic("Couldn't allocate Unix98 pts driver"); ptm_driver->driver_name = "pty_master"; @@ -692,8 +706,6 @@ static void __init unix98_pty_init(void) ptm_driver->init_termios.c_lflag = 0; ptm_driver->init_termios.c_ispeed = 38400; ptm_driver->init_termios.c_ospeed = 38400; - ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | - TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; ptm_driver->other = pts_driver; tty_set_operations(ptm_driver, &ptm_unix98_ops); @@ -707,8 +719,6 @@ static void __init unix98_pty_init(void) pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; pts_driver->init_termios.c_ispeed = 38400; pts_driver->init_termios.c_ospeed = 38400; - pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | - TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; pts_driver->other = ptm_driver; tty_set_operations(pts_driver, &pty_unix98_ops); |