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gigaset: in file ops, check for device disconnect before anything else
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When the device is disconnected, the dev structure goes away, so
trying to report another error via dev_printk is bound to oops.
To avoid that, first check whether the device is still connected
and return quietly if it isn't.

Impact: error handling

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Tested-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Tilman Schmidt authored and David S. Miller committed Apr 7, 2009
1 parent 368fd81 commit 51370e5
Showing 1 changed file with 30 additions and 28 deletions.
58 changes: 30 additions & 28 deletions drivers/isdn/gigaset/interface.c
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Original file line number Diff line number Diff line change
Expand Up @@ -193,7 +193,9 @@ static void if_close(struct tty_struct *tty, struct file *filp)

mutex_lock(&cs->mutex);

if (!cs->open_count)
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 {
if (!--cs->open_count) {
Expand Down Expand Up @@ -228,7 +230,10 @@ static int if_ioctl(struct tty_struct *tty, struct file *file,
if (mutex_lock_interruptible(&cs->mutex))
return -ERESTARTSYS; // FIXME -EINTR?

if (!cs->open_count)
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 {
retval = 0;
Expand All @@ -248,13 +253,6 @@ static int if_ioctl(struct tty_struct *tty, struct file *file,
retval = put_user(int_arg, (int __user *) arg);
break;
case GIGASET_BRKCHARS:
//FIXME test if MS_LOCKED
if (!cs->connected) {
gig_dbg(DEBUG_ANY,
"can't communicate with unplugged device");
retval = -ENODEV;
break;
}
retval = copy_from_user(&buf,
(const unsigned char __user *) arg, 6)
? -EFAULT : 0;
Expand Down Expand Up @@ -331,7 +329,7 @@ static int if_tiocmset(struct tty_struct *tty, struct file *file,
return -ERESTARTSYS; // FIXME -EINTR?

if (!cs->connected) {
gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
gig_dbg(DEBUG_IF, "not connected");
retval = -ENODEV;
} else {
mc = (cs->control_state | set) & ~clear & (TIOCM_RTS|TIOCM_DTR);
Expand Down Expand Up @@ -360,14 +358,14 @@ static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
if (mutex_lock_interruptible(&cs->mutex))
return -ERESTARTSYS; // FIXME -EINTR?

if (!cs->open_count)
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) {
dev_warn(cs->dev, "can't write to unlocked device\n");
retval = -EBUSY;
} else if (!cs->connected) {
gig_dbg(DEBUG_ANY, "can't write to unplugged device");
retval = -EBUSY; //FIXME
} else {
retval = cs->ops->write_cmd(cs, buf, count,
&cs->if_wake_tasklet);
Expand All @@ -394,14 +392,14 @@ static int if_write_room(struct tty_struct *tty)
if (mutex_lock_interruptible(&cs->mutex))
return -ERESTARTSYS; // FIXME -EINTR?

if (!cs->open_count)
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) {
dev_warn(cs->dev, "can't write to unlocked device\n");
retval = -EBUSY;
} else if (!cs->connected) {
gig_dbg(DEBUG_ANY, "can't write to unplugged device");
retval = -EBUSY; //FIXME
} else
retval = cs->ops->write_room(cs);

Expand All @@ -426,14 +424,14 @@ static int if_chars_in_buffer(struct tty_struct *tty)
if (mutex_lock_interruptible(&cs->mutex))
return -ERESTARTSYS; // FIXME -EINTR?

if (!cs->open_count)
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) {
dev_warn(cs->dev, "can't write to unlocked device\n");
retval = -EBUSY;
} else if (!cs->connected) {
gig_dbg(DEBUG_ANY, "can't write to unplugged device");
retval = -EBUSY; //FIXME
} else
retval = cs->ops->chars_in_buffer(cs);

Expand All @@ -456,7 +454,9 @@ static void if_throttle(struct tty_struct *tty)

mutex_lock(&cs->mutex);

if (!cs->open_count)
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 {
//FIXME
Expand All @@ -479,7 +479,9 @@ static void if_unthrottle(struct tty_struct *tty)

mutex_lock(&cs->mutex);

if (!cs->open_count)
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 {
//FIXME
Expand All @@ -506,13 +508,13 @@ static void if_set_termios(struct tty_struct *tty, struct ktermios *old)

mutex_lock(&cs->mutex);

if (!cs->open_count) {
dev_warn(cs->dev, "%s: device not opened\n", __func__);
if (!cs->connected) {
gig_dbg(DEBUG_IF, "not connected");
goto out;
}

if (!cs->connected) {
gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
if (!cs->open_count) {
dev_warn(cs->dev, "%s: device not opened\n", __func__);
goto out;
}

Expand Down

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