diff options
author | Jiri Slaby <jslaby@suse.cz> | 2012-03-05 13:52:54 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-03-08 20:51:13 (GMT) |
commit | fc258f89405f63b379324d1f8388ae4810297997 (patch) | |
tree | 7027aadb38d74ff01e24c759339e75b16e0515dd /drivers | |
parent | 5dd5bc40f3b6e0ccdaad948dbadc94ad0906cb25 (diff) | |
download | linux-fc258f89405f63b379324d1f8388ae4810297997.tar.xz |
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: Jiri 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/isdn/gigaset/interface.c | 105 |
1 files changed, 14 insertions, 91 deletions
diff --git a/drivers/isdn/gigaset/interface.c b/drivers/isdn/gigaset/interface.c index 648260b..8ff50b0 100644 --- a/drivers/isdn/gigaset/interface.c +++ b/drivers/isdn/gigaset/interface.c @@ -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; |