[PATCH 64/76] tty: some ICANON magic is in the wrong places

Alan Cox
2008-10-05T16:31:09Z

Move the set up on ldisc change into the ldisc
Move the INQ/OUTQ cases into the driver not in shared ioctl code where it
gives bogus answers for other ldisc values

Signed-off-by: Alan Cox <alan@redhat.com>
---

drivers/bluetooth/hci_ldisc.c | 2 +-
drivers/char/n_hdlc.c | 2 +-
drivers/char/n_tty.c | 53 +++++++++++++++++++++++++++++++++++++++--
drivers/char/tty_ioctl.c | 42 ++------------------------------
include/linux/tty.h | 2 +-
5 files changed, 56 insertions(+), 45 deletions(-)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 8dfcf77..4426bb5 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -484,7 +484,7 @@ static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,
return -EUNATCH;

default:
- err = n_tty_ioctl(tty, file, cmd, arg);
+ err = n_tty_ioctl_helper(tty, file, cmd, arg);
break;
};

diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c
index 69ec639..bacb3e2 100644
--- a/drivers/char/n_hdlc.c
+++ b/drivers/char/n_hdlc.c
@@ -764,7 +764,7 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
break;

default:
- error = n_tty_ioctl (tty, file, cmd, arg);
+ error = n_tty_ioctl_helper(tty, file, cmd, arg);
break;
}
return error;
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index 708c2b1..b4f5dcc 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -1011,8 +1011,20 @@ int is_ignored(int sig)

static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
{
- if (!tty)
- return;
+ int canon_change = 1;
+ BUG_ON(!tty);
+
+ if (old)
+ canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON;
+ if (canon_change) {
+ memset(&tty->read_flags, 0, sizeof tty->read_flags);
+ tty->canon_head = tty->read_tail;
+ tty->canon_data = 0;
+ tty->erasing = 0;
+ }
+
+ if (canon_change && !L_ICANON(tty) && tty->read_cnt)
+ wake_up_interruptible(&tty->read_wait);

tty->icanon = (L_ICANON(tty) != 0);
if (test_bit(TTY_HW_COOK_IN, &tty->flags)) {
@@ -1573,6 +1585,43 @@ static unsigned int normal_poll(struct tty_struct *tty, struct file *file,
return mask;
}

+static unsigned long inq_canon(struct tty_struct *tty)
+{
+ int nr, head, tail;
+
+ if (!tty->canon_data || !tty->read_buf)
+ return 0;
+ head = tty->canon_head;
+ tail = tty->read_tail;
+ nr = (head - tail) & (N_TTY_BUF_SIZE-1);
+ /* Skip EOF-chars.. */
+ while (head != tail) {
+ if (test_bit(tail, tty->read_flags) &&
+ tty->read_buf[tail] == __DISABLED_CHAR)
+ nr--;
+ tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+ }
+ return nr;
+}
+
+static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int retval;
+
+ switch (cmd) {
+ case TIOCOUTQ:
+ return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
+ case TIOCINQ:
+ retval = tty->read_cnt;
+ if (L_ICANON(tty))
+ retval = inq_canon(tty);
+ return put_user(retval, (unsigned int __user *) arg);
+ default:
+ return n_tty_ioctl_helper(tty, file, cmd, arg);
+ }
+}
+
struct tty_ldisc_ops tty_ldisc_N_TTY = {
.magic = TTY_LDISC_MAGIC,
.name = "n_tty",
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index 14cc19c..a408c8e 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -489,7 +489,6 @@ EXPORT_SYMBOL(tty_termios_hw_change);

static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
- int canon_change;
struct ktermios old_termios;
struct tty_ldisc *ld;
unsigned long flags;
@@ -505,18 +504,6 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
old_termios = *tty->termios;
*tty->termios = *new_termios;
unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
- canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
- if (canon_change) {
- memset(&tty->read_flags, 0, sizeof tty->read_flags);
- tty->canon_head = tty->read_tail;
- tty->canon_data = 0;
- tty->erasing = 0;
- }
-
- /* This bit should be in the ldisc code */
- if (canon_change && !L_ICANON(tty) && tty->read_cnt)
- /* Get characters left over from canonical mode. */
- wake_up_interruptible(&tty->read_wait);

/* See if packet mode change of state. */
if (tty->link && tty->link->packet) {
@@ -677,24 +664,6 @@ static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)

#endif

-static unsigned long inq_canon(struct tty_struct *tty)
-{
- int nr, head, tail;
-
- if (!tty->canon_data || !tty->read_buf)
- return 0;
- head = tty->canon_head;
- tail = tty->read_tail;
- nr = (head - tail) & (N_TTY_BUF_SIZE-1);
- /* Skip EOF-chars.. */
- while (head != tail) {
- if (test_bit(tail, tty->read_flags) &&
- tty->read_buf[tail] == __DISABLED_CHAR)
- nr--;
- tail = (tail+1) & (N_TTY_BUF_SIZE-1);
- }
- return nr;
-}

#ifdef TIOCGETP
/*
@@ -1110,7 +1079,7 @@ int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
}
EXPORT_SYMBOL_GPL(tty_perform_flush);

-int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
unsigned long flags;
@@ -1148,13 +1117,6 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file,
return 0;
case TCFLSH:
return tty_perform_flush(tty, arg);
- case TIOCOUTQ:
- return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
- case TIOCINQ:
- retval = tty->read_cnt;
- if (L_ICANON(tty))
- retval = inq_canon(tty);
- return put_user(retval, (unsigned int __user *) arg);
case TIOCPKT:
{
int pktmode;
@@ -1180,4 +1142,4 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file,
return tty_mode_ioctl(tty, file, cmd, arg);
}
}
-EXPORT_SYMBOL(n_tty_ioctl);
+EXPORT_SYMBOL(n_tty_ioctl_helper);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 3c7c757..3b8121d 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -466,7 +466,7 @@ static inline void tty_audit_push_task(struct task_struct *tsk,
#endif

/* tty_ioctl.c */
-extern int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg);

/* serial.c */