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path: root/drivers/tty/n_tty.c
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Diffstat (limited to 'drivers/tty/n_tty.c')
-rw-r--r--drivers/tty/n_tty.c81
1 files changed, 37 insertions, 44 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 26f097f60b10..d2b496750d59 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -321,7 +321,8 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata)
{
- *read_buf_addr(ldata, ldata->read_head++) = c;
+ *read_buf_addr(ldata, ldata->read_head) = c;
+ ldata->read_head++;
}
/**
@@ -351,13 +352,13 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty)
{
unsigned long flags;
- spin_lock_irqsave(&tty->ctrl_lock, flags);
if (tty->link->packet) {
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
tty->ctrl_status |= TIOCPKT_FLUSHREAD;
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
if (waitqueue_active(&tty->link->read_wait))
wake_up_interruptible(&tty->link->read_wait);
}
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
}
/**
@@ -2128,7 +2129,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
int minimum, time;
ssize_t retval = 0;
long timeout;
- unsigned long flags;
int packet;
c = job_control(tty, file);
@@ -2174,10 +2174,10 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
unsigned char cs;
if (b != buf)
break;
- spin_lock_irqsave(&tty->link->ctrl_lock, flags);
+ spin_lock_irq(&tty->link->ctrl_lock);
cs = tty->link->ctrl_status;
tty->link->ctrl_status = 0;
- spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
+ spin_unlock_irq(&tty->link->ctrl_lock);
if (tty_put_user(tty, cs, b++)) {
retval = -EFAULT;
b--;
@@ -2193,45 +2193,29 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
if (!input_available_p(tty, 0)) {
if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
- up_read(&tty->termios_rwsem);
- tty_flush_to_ldisc(tty);
- down_read(&tty->termios_rwsem);
- if (!input_available_p(tty, 0)) {
- retval = -EIO;
- break;
- }
- } else {
- if (tty_hung_up_p(file))
- break;
- if (!timeout)
- break;
- if (file->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
- break;
- }
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
- n_tty_set_room(tty);
- up_read(&tty->termios_rwsem);
-
- timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
- timeout);
-
- down_read(&tty->termios_rwsem);
- continue;
+ retval = -EIO;
+ break;
}
- }
-
- /* Deal with packet mode. */
- if (packet && b == buf) {
- if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
- retval = -EFAULT;
- b--;
+ if (tty_hung_up_p(file))
+ break;
+ if (!timeout)
+ break;
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
break;
}
- nr--;
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+ n_tty_set_room(tty);
+ up_read(&tty->termios_rwsem);
+
+ timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
+ timeout);
+
+ down_read(&tty->termios_rwsem);
+ continue;
}
if (ldata->icanon && !L_EXTPROC(tty)) {
@@ -2243,8 +2227,17 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
break;
} else {
int uncopied;
- /* The copy function takes the read lock and handles
- locking internally for this case */
+
+ /* Deal with packet mode. */
+ if (packet && b == buf) {
+ if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
+ retval = -EFAULT;
+ b--;
+ break;
+ }
+ nr--;
+ }
+
uncopied = copy_from_read_buf(tty, &b, &nr);
uncopied += copy_from_read_buf(tty, &b, &nr);
if (uncopied) {