TTY: remove unneeded tty->index checks

Checking if tty->index is in bounds is not needed. The tty has the
index set in the initial open. This is done in get_tty_driver. And it
can be only in interval <0,driver->num).

So remove the tests which check exactly this interval. Some are
left untouched as they check against the current backing device count.
(Leaving apart that the check is racy in most of the cases.)

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 3 insertions, 9 deletions

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index baf08eba495c..3a7905b06e53 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -1013,8 +1013,7 @@ static const struct file_operations capi_fops =
 static int
 capinc_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
-        int idx = tty->index;
-        struct capiminor *mp = capiminor_get(idx);
+        struct capiminor *mp = capiminor_get(tty->index);
         int ret = tty_standard_install(driver, tty);
 
         if (ret == 0)
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index db621db67f61..ac0186e54bf4 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -1051,8 +1051,6 @@ static struct cardstate *gigaset_get_cs_by_minor(unsigned minor)
 
 struct cardstate *gigaset_get_cs_by_tty(struct tty_struct *tty)
 {
-        if (tty->index < 0 || tty->index >= tty->driver->num)
-                return NULL;
         return gigaset_get_cs_by_minor(tty->index + tty->driver->minor_start);
 }
 
diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
index 2c26b64ebbea..ac4840124bc0 100644
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -1590,12 +1590,9 @@ static int
 isdn_tty_open(struct tty_struct *tty, struct file *filp)
 {
         modem_info *info;
-        int retval, line;
+        int retval;
 
-        line = tty->index;
-        if (line < 0 || line >= ISDN_MAX_CHANNELS)
-                return -ENODEV;
-        info = &dev->mdm.info[line];
+        info = &dev->mdm.info[tty->index];
         if (isdn_tty_paranoia_check(info, tty->name, "isdn_tty_open"))
                 return -ENODEV;
         if (!try_module_get(info->owner)) {