diff options
| -rw-r--r-- | drivers/char/n_hdlc.c | 9 | ||||
| -rw-r--r-- | drivers/char/n_tty.c | 3 | ||||
| -rw-r--r-- | drivers/char/tty_io.c | 40 | ||||
| -rw-r--r-- | drivers/char/tty_ioctl.c | 4 | ||||
| -rw-r--r-- | include/linux/tty.h | 6 |
5 files changed, 43 insertions, 19 deletions
diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c index 337a87f86a3b..37f7d3403040 100644 --- a/drivers/char/n_hdlc.c +++ b/drivers/char/n_hdlc.c @@ -780,13 +780,14 @@ static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp, poll_wait(filp, &tty->write_wait, wait); /* set bits for operations that won't block */ - if(n_hdlc->rx_buf_list.head) + if (n_hdlc->rx_buf_list.head) mask |= POLLIN | POLLRDNORM; /* readable */ if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) mask |= POLLHUP; - if(tty_hung_up_p(filp)) + if (tty_hung_up_p(filp)) mask |= POLLHUP; - if(n_hdlc->tx_free_buf_list.head) + if (!tty_is_writelocked(tty) && + n_hdlc->tx_free_buf_list.head) mask |= POLLOUT | POLLWRNORM; /* writable */ } return mask; @@ -861,7 +862,7 @@ static void n_hdlc_buf_put(struct n_hdlc_buf_list *list, spin_lock_irqsave(&list->spinlock,flags); buf->link=NULL; - if(list->tail) + if (list->tail) list->tail->link = buf; else list->head = buf; diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index 154f42203b05..371631f4bfb9 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -1538,7 +1538,8 @@ static unsigned int normal_poll(struct tty_struct * tty, struct file * file, pol else tty->minimum_to_wake = 1; } - if (tty->driver->chars_in_buffer(tty) < WAKEUP_CHARS && + if (!tty_is_writelocked(tty) && + tty->driver->chars_in_buffer(tty) < WAKEUP_CHARS && tty->driver->write_room(tty) > 0) mask |= POLLOUT | POLLWRNORM; return mask; diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index a96f26a63fa2..a37e6330db8a 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1726,6 +1726,23 @@ static ssize_t tty_read(struct file * file, char __user * buf, size_t count, return i; } +void tty_write_unlock(struct tty_struct *tty) +{ + mutex_unlock(&tty->atomic_write_lock); + wake_up_interruptible(&tty->write_wait); +} + +int tty_write_lock(struct tty_struct *tty, int ndelay) +{ + if (!mutex_trylock(&tty->atomic_write_lock)) { + if (ndelay) + return -EAGAIN; + if (mutex_lock_interruptible(&tty->atomic_write_lock)) + return -ERESTARTSYS; + } + return 0; +} + /* * Split writes up in sane blocksizes to avoid * denial-of-service type attacks @@ -1737,13 +1754,12 @@ static inline ssize_t do_tty_write( const char __user *buf, size_t count) { - ssize_t ret = 0, written = 0; + ssize_t ret, written = 0; unsigned int chunk; - /* FIXME: O_NDELAY ... */ - if (mutex_lock_interruptible(&tty->atomic_write_lock)) { - return -ERESTARTSYS; - } + ret = tty_write_lock(tty, file->f_flags & O_NDELAY); + if (ret < 0) + return ret; /* * We chunk up writes into a temporary buffer. This @@ -1776,8 +1792,8 @@ static inline ssize_t do_tty_write( buf = kmalloc(chunk, GFP_KERNEL); if (!buf) { - mutex_unlock(&tty->atomic_write_lock); - return -ENOMEM; + ret = -ENOMEM; + goto out; } kfree(tty->write_buf); tty->write_cnt = chunk; @@ -1812,7 +1828,8 @@ static inline ssize_t do_tty_write( inode->i_mtime = current_fs_time(inode->i_sb); ret = written; } - mutex_unlock(&tty->atomic_write_lock); +out: + tty_write_unlock(tty); return ret; } @@ -3163,14 +3180,13 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) static int send_break(struct tty_struct *tty, unsigned int duration) { - if (mutex_lock_interruptible(&tty->atomic_write_lock)) + if (tty_write_lock(tty, 0) < 0) return -EINTR; tty->driver->break_ctl(tty, -1); - if (!signal_pending(current)) { + if (!signal_pending(current)) msleep_interruptible(duration); - } tty->driver->break_ctl(tty, 0); - mutex_unlock(&tty->atomic_write_lock); + tty_write_unlock(tty); if (signal_pending(current)) return -EINTR; return 0; diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index fd471cb3338f..918e24c885f1 100644 --- a/drivers/char/tty_ioctl.c +++ b/drivers/char/tty_ioctl.c @@ -667,7 +667,7 @@ static int send_prio_char(struct tty_struct *tty, char ch) return 0; } - if (mutex_lock_interruptible(&tty->atomic_write_lock)) + if (tty_write_lock(tty, 0) < 0) return -ERESTARTSYS; if (was_stopped) @@ -675,7 +675,7 @@ static int send_prio_char(struct tty_struct *tty, char ch) tty->driver->write(tty, &ch, 1); if (was_stopped) stop_tty(tty); - mutex_unlock(&tty->atomic_write_lock); + tty_write_unlock(tty); return 0; } diff --git a/include/linux/tty.h b/include/linux/tty.h index bb4576085203..deaba9ec5004 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -338,6 +338,12 @@ extern struct tty_struct *get_current_tty(void); extern struct mutex tty_mutex; +extern void tty_write_unlock(struct tty_struct *tty); +extern int tty_write_lock(struct tty_struct *tty, int ndelay); +#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) + + + /* n_tty.c */ extern struct tty_ldisc tty_ldisc_N_TTY; |