diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tty_io.c | 73 |
1 files changed, 37 insertions, 36 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 305e46db70e..558ca927e32 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -154,7 +154,7 @@ static int tty_release(struct inode *, struct file *); int tty_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg); static int tty_fasync(int fd, struct file * filp, int on); -static void release_mem(struct tty_struct *tty, int idx); +static void release_tty(struct tty_struct *tty, int idx); /** * alloc_tty_struct - allocate a tty object @@ -2002,7 +2002,7 @@ static int init_dev(struct tty_driver *driver, int idx, /* * All structures have been allocated, so now we install them. - * Failures after this point use release_mem to clean up, so + * Failures after this point use release_tty to clean up, so * there's no need to null out the local pointers. */ if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { @@ -2023,8 +2023,8 @@ static int init_dev(struct tty_driver *driver, int idx, /* * Structures all installed ... call the ldisc open routines. - * If we fail here just call release_mem to clean up. No need - * to decrement the use counts, as release_mem doesn't care. + * If we fail here just call release_tty to clean up. No need + * to decrement the use counts, as release_tty doesn't care. */ if (tty->ldisc.open) { @@ -2094,17 +2094,17 @@ fail_no_mem: retval = -ENOMEM; goto end_init; - /* call the tty release_mem routine to clean out this slot */ + /* call the tty release_tty routine to clean out this slot */ release_mem_out: if (printk_ratelimit()) printk(KERN_INFO "init_dev: ldisc open failed, " "clearing slot %d\n", idx); - release_mem(tty, idx); + release_tty(tty, idx); goto end_init; } /** - * release_mem - release tty structure memory + * release_one_tty - release tty structure memory * * Releases memory associated with a tty structure, and clears out the * driver table slots. This function is called when a device is no longer @@ -2116,37 +2116,14 @@ release_mem_out: * of ttys that the driver keeps. * FIXME: should we require tty_mutex is held here ?? */ - -static void release_mem(struct tty_struct *tty, int idx) +static void release_one_tty(struct tty_struct *tty, int idx) { - struct tty_struct *o_tty; - struct ktermios *tp; int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM; - - if ((o_tty = tty->link) != NULL) { - if (!devpts) - o_tty->driver->ttys[idx] = NULL; - if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { - tp = o_tty->termios; - if (!devpts) - o_tty->driver->termios[idx] = NULL; - kfree(tp); - - tp = o_tty->termios_locked; - if (!devpts) - o_tty->driver->termios_locked[idx] = NULL; - kfree(tp); - } - o_tty->magic = 0; - o_tty->driver->refcount--; - file_list_lock(); - list_del_init(&o_tty->tty_files); - file_list_unlock(); - free_tty_struct(o_tty); - } + struct ktermios *tp; if (!devpts) tty->driver->ttys[idx] = NULL; + if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { tp = tty->termios; if (!devpts) @@ -2159,15 +2136,39 @@ static void release_mem(struct tty_struct *tty, int idx) kfree(tp); } + tty->magic = 0; tty->driver->refcount--; + file_list_lock(); list_del_init(&tty->tty_files); file_list_unlock(); - module_put(tty->driver->owner); + free_tty_struct(tty); } +/** + * release_tty - release tty structure memory + * + * Release both @tty and a possible linked partner (think pty pair), + * and decrement the refcount of the backing module. + * + * Locking: + * tty_mutex - sometimes only + * takes the file list lock internally when working on the list + * of ttys that the driver keeps. + * FIXME: should we require tty_mutex is held here ?? + */ +static void release_tty(struct tty_struct *tty, int idx) +{ + struct tty_driver *driver = tty->driver; + + if (tty->link) + release_one_tty(tty->link, idx); + release_one_tty(tty, idx); + module_put(driver->owner); +} + /* * Even releasing the tty structures is a tricky business.. We have * to be very careful that the structures are all released at the @@ -2435,10 +2436,10 @@ static void release_dev(struct file * filp) tty_set_termios_ldisc(o_tty,N_TTY); } /* - * The release_mem function takes care of the details of clearing + * The release_tty function takes care of the details of clearing * the slots and preserving the termios structure. */ - release_mem(tty, idx); + release_tty(tty, idx); #ifdef CONFIG_UNIX98_PTYS /* Make this pty number available for reallocation */ |