diff options
Diffstat (limited to 'drivers/char/pty.c')
| -rw-r--r-- | drivers/char/pty.c | 126 |
1 files changed, 114 insertions, 12 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c index c98450023030..c5a192dd00db 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 */ |