diff options
Diffstat (limited to 'drivers/char/pty.c')
| -rw-r--r-- | drivers/char/pty.c | 54 |
1 files changed, 31 insertions, 23 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c index b33d6688e91..62f282e6763 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -18,6 +18,7 @@ #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/fcntl.h> +#include <linux/sched.h> #include <linux/string.h> #include <linux/major.h> #include <linux/mm.h> @@ -120,8 +121,10 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) /* Stuff the data into the input queue of the other end */ c = tty_insert_flip_string(to, buf, c); /* And shovel */ - tty_flip_buffer_push(to); - tty_wakeup(tty); + if (c) { + tty_flip_buffer_push(to); + tty_wakeup(tty); + } } return c; } @@ -259,6 +262,9 @@ done: return 0; } +/* Traditional BSD devices */ +#ifdef CONFIG_LEGACY_PTYS + static int pty_install(struct tty_driver *driver, struct tty_struct *tty) { struct tty_struct *o_tty; @@ -308,24 +314,6 @@ free_mem_out: return -ENOMEM; } - -static const struct tty_operations pty_ops = { - .install = pty_install, - .open = pty_open, - .close = pty_close, - .write = pty_write, - .write_room = pty_write_room, - .flush_buffer = pty_flush_buffer, - .chars_in_buffer = pty_chars_in_buffer, - .unthrottle = pty_unthrottle, - .set_termios = pty_set_termios, - .resize = pty_resize -}; - -/* Traditional BSD devices */ -#ifdef CONFIG_LEGACY_PTYS -static struct tty_driver *pty_driver, *pty_slave_driver; - static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg) { @@ -339,7 +327,12 @@ static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, static int legacy_count = CONFIG_LEGACY_PTY_COUNT; module_param(legacy_count, int, 0); -static const struct tty_operations pty_ops_bsd = { +/* + * The master side of a pty can do TIOCSPTLCK and thus + * has pty_bsd_ioctl. + */ +static const struct tty_operations master_pty_ops_bsd = { + .install = pty_install, .open = pty_open, .close = pty_close, .write = pty_write, @@ -352,8 +345,23 @@ static const struct tty_operations pty_ops_bsd = { .resize = pty_resize }; +static const struct tty_operations slave_pty_ops_bsd = { + .install = pty_install, + .open = pty_open, + .close = pty_close, + .write = pty_write, + .write_room = pty_write_room, + .flush_buffer = pty_flush_buffer, + .chars_in_buffer = pty_chars_in_buffer, + .unthrottle = pty_unthrottle, + .set_termios = pty_set_termios, + .resize = pty_resize +}; + static void __init legacy_pty_init(void) { + struct tty_driver *pty_driver, *pty_slave_driver; + if (legacy_count <= 0) return; @@ -381,7 +389,7 @@ static void __init legacy_pty_init(void) 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, &pty_ops); + tty_set_operations(pty_driver, &master_pty_ops_bsd); pty_slave_driver->owner = THIS_MODULE; pty_slave_driver->driver_name = "pty_slave"; @@ -397,7 +405,7 @@ static void __init legacy_pty_init(void) pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; pty_slave_driver->other = pty_driver; - tty_set_operations(pty_slave_driver, &pty_ops); + tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); if (tty_register_driver(pty_driver)) panic("Couldn't register pty driver"); |