diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/pty.c | 126 | ||||
| -rw-r--r-- | drivers/char/tty_io.c | 198 |
2 files changed, 182 insertions, 142 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c index c9845002303..c5a192dd00d 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -227,7 +227,58 @@ static void pty_set_termios(struct tty_struct *tty, struct ktermios *old_termios tty->termios->c_cflag |= (CS8 | CREAD); } +static int pty_install(struct tty_driver *driver, struct tty_struct *tty) +{ + struct tty_struct *o_tty; + int idx = tty->index; + int retval; + + o_tty = alloc_tty_struct(); + if (!o_tty) + return -ENOMEM; + if (!try_module_get(driver->other->owner)) { + /* This cannot in fact currently happen */ + free_tty_struct(o_tty); + return -ENOMEM; + } + 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 free_mem_out; + + retval = tty_init_termios(o_tty); + if (retval) { + tty_free_termios(tty); + goto free_mem_out; + } + + /* + * 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_driver_kref_get(driver); + tty->count++; + driver->ttys[idx] = tty; + return 0; +free_mem_out: + module_put(o_tty->driver->owner); + free_tty_struct(o_tty); + return -ENOMEM; +} + + static const struct tty_operations pty_ops = { + .install = pty_install, .open = pty_open, .close = pty_close, .write = pty_write, @@ -332,6 +383,7 @@ static inline void legacy_pty_init(void) { } int pty_limit = NR_UNIX98_PTY_DEFAULT; static int pty_limit_min = 0; static int pty_limit_max = NR_UNIX98_PTY_MAX; +static int pty_count = 0; static struct cdev ptmx_cdev; @@ -351,6 +403,7 @@ static struct ctl_table pty_table[] = { .procname = "nr", .maxlen = sizeof(int), .mode = 0444, + .data = &pty_count, .proc_handler = &proc_dointvec, }, { .ctl_name = 0 @@ -426,7 +479,7 @@ static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, int idx) return tty; } -static void pty_shutdown(struct tty_struct *tty) +static void pty_unix98_shutdown(struct tty_struct *tty) { /* We have our own method as we don't use the tty index */ kfree(tty->termios); @@ -436,19 +489,71 @@ static void pty_shutdown(struct tty_struct *tty) /* We have no need to install and remove our tty objects as devpts does all the work for us */ -static int pty_install(struct tty_driver *driver, struct tty_struct *tty) +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 */ + free_tty_struct(o_tty); + return -ENOMEM; + } + initialize_tty_struct(o_tty, driver->other, idx); + + tty->termios = kmalloc(sizeof(struct ktermios), GFP_KERNEL); + if (tty->termios == NULL) + goto free_mem_out; + *tty->termios = driver->init_termios; + tty->termios_locked = kzalloc(sizeof(struct ktermios), GFP_KERNEL); + if (tty->termios_locked == NULL) + goto free_mem_out; + o_tty->termios = kmalloc(sizeof(struct ktermios), GFP_KERNEL); + if (o_tty->termios == NULL) + goto free_mem_out; + *o_tty->termios = driver->other->init_termios; + o_tty->termios_locked = kzalloc(sizeof(struct ktermios), GFP_KERNEL); + if (o_tty->termios_locked == NULL) + goto free_mem_out; + + 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++; + pty_count++; return 0; +free_mem_out: + kfree(o_tty->termios); + module_put(o_tty->driver->owner); + free_tty_struct(o_tty); + kfree(tty->termios_locked); + kfree(tty->termios); + free_tty_struct(tty); + module_put(driver->owner); + return -ENOMEM; } -static void pty_remove(struct tty_driver *driver, struct tty_struct *tty) +static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) { + pty_count--; } static const struct tty_operations ptm_unix98_ops = { .lookup = ptm_unix98_lookup, - .install = pty_install, - .remove = pty_remove, + .install = pty_unix98_install, + .remove = pty_unix98_remove, .open = pty_open, .close = pty_close, .write = pty_write, @@ -458,13 +563,13 @@ static const struct tty_operations ptm_unix98_ops = { .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, .ioctl = pty_unix98_ioctl, - .shutdown = pty_shutdown + .shutdown = pty_unix98_shutdown }; static const struct tty_operations pty_unix98_ops = { .lookup = pts_unix98_lookup, - .install = pty_install, - .remove = pty_remove, + .install = pty_unix98_install, + .remove = pty_unix98_remove, .open = pty_open, .close = pty_close, .write = pty_write, @@ -473,6 +578,7 @@ 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 }; /** @@ -589,10 +695,6 @@ static void __init unix98_pty_init(void) if (tty_register_driver(pts_driver)) panic("Couldn't register Unix98 pts driver"); - /* FIXME: WTF */ -#if 0 - pty_table[1].data = &ptm_driver->refcount; -#endif register_sysctl_table(pty_root_table); /* Now create the /dev/ptmx special device */ diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index b0ad4880c3a..e881e9ed08d 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -136,8 +136,6 @@ LIST_HEAD(tty_drivers); /* linked list of tty drivers */ DEFINE_MUTEX(tty_mutex); EXPORT_SYMBOL(tty_mutex); -static void initialize_tty_struct(struct tty_struct *tty); - static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); ssize_t redirected_tty_write(struct file *, const char __user *, @@ -166,7 +164,7 @@ static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); * Locking: none */ -static struct tty_struct *alloc_tty_struct(void) +struct tty_struct *alloc_tty_struct(void) { return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); } @@ -180,7 +178,7 @@ static struct tty_struct *alloc_tty_struct(void) * Locking: none. Must be called after tty is definitely unused */ -static inline void free_tty_struct(struct tty_struct *tty) +void free_tty_struct(struct tty_struct *tty) { kfree(tty->write_buf); tty_buffer_free_all(tty); @@ -1227,22 +1225,70 @@ struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, int idx) } /** + * tty_init_termios - helper for termios setup + * @tty: the tty to set up + * + * Initialise the termios structures for this tty. Thus runs under + * the tty_mutex currently so we can be relaxed about ordering. + */ + +int tty_init_termios(struct tty_struct *tty) +{ + struct ktermios *tp, *ltp; + int idx = tty->index; + + tp = tty->driver->termios[idx]; + ltp = tty->driver->termios_locked[idx]; + if (tp == NULL) { + WARN_ON(ltp != NULL); + tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); + ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); + if (tp == NULL || ltp == NULL) { + kfree(tp); + kfree(ltp); + return -ENOMEM; + } + memcpy(tp, &tty->driver->init_termios, + sizeof(struct ktermios)); + tty->driver->termios[idx] = tp; + tty->driver->termios_locked[idx] = ltp; + } + tty->termios = tp; + tty->termios_locked = ltp; + + /* Compatibility until drivers always set this */ + tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); + tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); + return 0; +} + +/** * tty_driver_install_tty() - install a tty entry in the driver * @driver: the driver for the tty * @tty: the tty * * Install a tty object into the driver tables. The tty->index field - * will be set by the time this is called. + * will be set by the time this is called. This method is responsible + * for ensuring any need additional structures are allocated and + * configured. * * Locking: tty_mutex for now */ static int tty_driver_install_tty(struct tty_driver *driver, struct tty_struct *tty) { + int idx = tty->index; + if (driver->ops->install) return driver->ops->install(driver, tty); - driver->ttys[tty->index] = tty; - return 0; + + if (tty_init_termios(tty) == 0) { + tty_driver_kref_get(driver); + tty->count++; + driver->ttys[idx] = tty; + return 0; + } + return -ENOMEM; } /** @@ -1327,9 +1373,7 @@ static int tty_reopen(struct tty_struct *tty) struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, int first_ok) { - struct tty_struct *tty, *o_tty; - struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc; - struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; + struct tty_struct *tty; int retval; /* check whether we're reopening an existing tty */ @@ -1361,118 +1405,17 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, if (!try_module_get(driver->owner)) return ERR_PTR(-ENODEV); - o_tty = NULL; - tp = o_tp = NULL; - ltp = o_ltp = NULL; - tty = alloc_tty_struct(); if (!tty) goto fail_no_mem; - initialize_tty_struct(tty); - tty->driver = driver; - tty->ops = driver->ops; - tty->index = idx; - tty_line_name(driver, idx, tty->name); - - if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { - tp_loc = &tty->termios; - ltp_loc = &tty->termios_locked; - } else { - tp_loc = &driver->termios[idx]; - ltp_loc = &driver->termios_locked[idx]; - } - - if (!*tp_loc) { - tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); - if (!tp) - goto free_mem_out; - *tp = driver->init_termios; - } - - if (!*ltp_loc) { - ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); - if (!ltp) - goto free_mem_out; - } - - if (driver->type == TTY_DRIVER_TYPE_PTY) { - o_tty = alloc_tty_struct(); - if (!o_tty) - goto free_mem_out; - if (!try_module_get(driver->other->owner)) { - /* This cannot in fact currently happen */ - free_tty_struct(o_tty); - o_tty = NULL; - goto free_mem_out; - } - initialize_tty_struct(o_tty); - o_tty->driver = driver->other; - o_tty->ops = driver->ops; - o_tty->index = idx; - tty_line_name(driver->other, idx, o_tty->name); - - if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { - o_tp_loc = &o_tty->termios; - o_ltp_loc = &o_tty->termios_locked; - } else { - o_tp_loc = &driver->other->termios[idx]; - o_ltp_loc = &driver->other->termios_locked[idx]; - } - - if (!*o_tp_loc) { - o_tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); - if (!o_tp) - goto free_mem_out; - *o_tp = driver->other->init_termios; - } - - if (!*o_ltp_loc) { - o_ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); - if (!o_ltp) - goto free_mem_out; - } - - /* - * Everything allocated ... set up the o_tty structure. - */ - if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) - driver->other->ttys[idx] = o_tty; - if (!*o_tp_loc) - *o_tp_loc = o_tp; - if (!*o_ltp_loc) - *o_ltp_loc = o_ltp; - o_tty->termios = *o_tp_loc; - o_tty->termios_locked = *o_ltp_loc; - 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. - */ - - if (!*tp_loc) - *tp_loc = tp; - if (!*ltp_loc) - *ltp_loc = ltp; - tty->termios = *tp_loc; - tty->termios_locked = *ltp_loc; - /* Compatibility until drivers always set this */ - tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); - tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); - tty_driver_kref_get(driver); - tty->count++; + initialize_tty_struct(tty, driver, idx); retval = tty_driver_install_tty(driver, tty); - if (retval < 0) - goto release_mem_out; + if (retval < 0) { + free_tty_struct(tty); + module_put(driver->owner); + return ERR_PTR(retval); + } /* * Structures all installed ... call the ldisc open routines. @@ -1480,22 +1423,11 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, * to decrement the use counts, as release_tty doesn't care. */ - retval = tty_ldisc_setup(tty, o_tty); + retval = tty_ldisc_setup(tty, tty->link); if (retval) goto release_mem_out; return tty; - /* Release locally allocated memory ... nothing placed in slots */ -free_mem_out: - kfree(o_tp); - if (o_tty) { - module_put(o_tty->driver->owner); - free_tty_struct(o_tty); - } - kfree(ltp); - kfree(tp); - free_tty_struct(tty); - fail_no_mem: module_put(driver->owner); return ERR_PTR(-ENOMEM); @@ -2852,7 +2784,8 @@ EXPORT_SYMBOL(do_SAK); * Locking: none - tty in question must not be exposed at this point */ -static void initialize_tty_struct(struct tty_struct *tty) +void initialize_tty_struct(struct tty_struct *tty, + struct tty_driver *driver, int idx) { memset(tty, 0, sizeof(struct tty_struct)); kref_init(&tty->kref); @@ -2873,6 +2806,11 @@ static void initialize_tty_struct(struct tty_struct *tty) spin_lock_init(&tty->ctrl_lock); INIT_LIST_HEAD(&tty->tty_files); INIT_WORK(&tty->SAK_work, do_SAK_work); + + tty->driver = driver; + tty->ops = driver->ops; + tty->index = idx; + tty_line_name(driver, idx, tty->name); } /** |