Commit fc258f89 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

TTY: isdn/gigaset, do not set tty->driver_data to NULL 



Close the window in open where driver_data is reset to NULL on each
open. It could cause other processes to get invalid retval from the
tty->ops operations because of the checks all over the code.

With this change we may do other cleanups. Now, the only valid check
for tty->driver_data != NULL is in close. This can happen only if open
fails at gigaset_get_cs_by_tty or try_module_get. The rest of checks
in various tty->ops->* are invalid as driver_data cannot be NULL
there. The same holds for cs->open_count. So remove them.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: gigaset307x-common@lists.sourceforge.net
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5dd5bc40

drivers/isdn/gigaset/interface.c

+14 −91
Original line number Diff line number Diff line
@@ -151,8 +151,6 @@ static int if_open(struct tty_struct *tty, struct file *filp) 
	gig_dbg(DEBUG_IF, "%d+%d: %s()",

		tty->driver->minor_start, tty->index, __func__);



	tty->driver_data = NULL;



	cs = gigaset_get_cs_by_tty(tty);

	if (!cs || !try_module_get(cs->driver->owner))

		return -ENODEV;
@@ -178,12 +176,11 @@ static int if_open(struct tty_struct *tty, struct file *filp) 


static void if_close(struct tty_struct *tty, struct file *filp)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	unsigned long flags;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

	if (!cs) { /* happens if we didn't find cs in open */

		printk(KERN_DEBUG "%s: no cardstate\n", __func__);

		return;

	}
@@ -211,18 +208,12 @@ static void if_close(struct tty_struct *tty, struct file *filp) 
static int if_ioctl(struct tty_struct *tty,

		    unsigned int cmd, unsigned long arg)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	int retval = -ENODEV;

	int int_arg;

	unsigned char buf[6];

	unsigned version[4];



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return -ENODEV;

	}



	gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);



	if (mutex_lock_interruptible(&cs->mutex))
@@ -231,9 +222,7 @@ static int if_ioctl(struct tty_struct *tty, 
	if (!cs->connected) {

		gig_dbg(DEBUG_IF, "not connected");

		retval = -ENODEV;

	} else if (!cs->open_count)

		dev_warn(cs->dev, "%s: device not opened\n", __func__);

	else {

	} else {

		retval = 0;

		switch (cmd) {

		case GIGASET_REDIR:
@@ -285,15 +274,9 @@ static int if_ioctl(struct tty_struct *tty, 


static int if_tiocmget(struct tty_struct *tty)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	int retval;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return -ENODEV;

	}



	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);



	if (mutex_lock_interruptible(&cs->mutex))
@@ -309,16 +292,10 @@ static int if_tiocmget(struct tty_struct *tty) 
static int if_tiocmset(struct tty_struct *tty,

		       unsigned int set, unsigned int clear)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	int retval;

	unsigned mc;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return -ENODEV;

	}



	gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",

		cs->minor_index, __func__, set, clear);
@@ -341,16 +318,10 @@ static int if_tiocmset(struct tty_struct *tty, 


static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	struct cmdbuf_t *cb;

	int retval;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return -ENODEV;

	}



	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);



	if (mutex_lock_interruptible(&cs->mutex))
@@ -361,11 +332,6 @@ static int if_write(struct tty_struct *tty, const unsigned char *buf, int count) 
		retval = -ENODEV;

		goto done;

	}

	if (!cs->open_count) {

		dev_warn(cs->dev, "%s: device not opened\n", __func__);

		retval = -ENODEV;

		goto done;

	}

	if (cs->mstate != MS_LOCKED) {

		dev_warn(cs->dev, "can't write to unlocked device\n");

		retval = -EBUSY;
@@ -397,15 +363,9 @@ done: 


static int if_write_room(struct tty_struct *tty)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	int retval = -ENODEV;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return -ENODEV;

	}



	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);



	if (mutex_lock_interruptible(&cs->mutex))
@@ -414,9 +374,7 @@ static int if_write_room(struct tty_struct *tty) 
	if (!cs->connected) {

		gig_dbg(DEBUG_IF, "not connected");

		retval = -ENODEV;

	} else if (!cs->open_count)

		dev_warn(cs->dev, "%s: device not opened\n", __func__);

	else if (cs->mstate != MS_LOCKED) {

	} else if (cs->mstate != MS_LOCKED) {

		dev_warn(cs->dev, "can't write to unlocked device\n");

		retval = -EBUSY;

	} else
@@ -429,23 +387,15 @@ static int if_write_room(struct tty_struct *tty) 


static int if_chars_in_buffer(struct tty_struct *tty)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	int retval = 0;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return 0;

	}



	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);



	mutex_lock(&cs->mutex);



	if (!cs->connected)

		gig_dbg(DEBUG_IF, "not connected");

	else if (!cs->open_count)

		dev_warn(cs->dev, "%s: device not opened\n", __func__);

	else if (cs->mstate != MS_LOCKED)

		dev_warn(cs->dev, "can't write to unlocked device\n");

	else
@@ -458,13 +408,7 @@ static int if_chars_in_buffer(struct tty_struct *tty) 


static void if_throttle(struct tty_struct *tty)

{

	struct cardstate *cs;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return;

	}

	struct cardstate *cs = tty->driver_data;



	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
@@ -472,8 +416,6 @@ static void if_throttle(struct tty_struct *tty) 


	if (!cs->connected)

		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */

	else if (!cs->open_count)

		dev_warn(cs->dev, "%s: device not opened\n", __func__);

	else

		gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
@@ -482,13 +424,7 @@ static void if_throttle(struct tty_struct *tty) 


static void if_unthrottle(struct tty_struct *tty)

{

	struct cardstate *cs;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return;

	}

	struct cardstate *cs = tty->driver_data;



	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
@@ -496,8 +432,6 @@ static void if_unthrottle(struct tty_struct *tty) 


	if (!cs->connected)

		gig_dbg(DEBUG_IF, "not connected");	/* nothing to do */

	else if (!cs->open_count)

		dev_warn(cs->dev, "%s: device not opened\n", __func__);

	else

		gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
@@ -506,18 +440,12 @@ static void if_unthrottle(struct tty_struct *tty) 


static void if_set_termios(struct tty_struct *tty, struct ktermios *old)

{

	struct cardstate *cs;

	struct cardstate *cs = tty->driver_data;

	unsigned int iflag;

	unsigned int cflag;

	unsigned int old_cflag;

	unsigned int control_state, new_state;



	cs = (struct cardstate *) tty->driver_data;

	if (!cs) {

		pr_err("%s: no cardstate\n", __func__);

		return;

	}



	gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);



	mutex_lock(&cs->mutex);
@@ -527,11 +455,6 @@ static void if_set_termios(struct tty_struct *tty, struct ktermios *old) 
		goto out;

	}



	if (!cs->open_count) {

		dev_warn(cs->dev, "%s: device not opened\n", __func__);

		goto out;

	}



	iflag = tty->termios->c_iflag;

	cflag = tty->termios->c_cflag;

	old_cflag = old ? old->c_cflag : cflag;

CRA Git | Maintained and supported by SUSTech CRA and CCSE