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>

arch/ia64/hp/sim/simserial.c

@@ -769,13 +769,10 @@ startup(struct async_struct *info)
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct async_struct	*info;
-	int			retval, line;
+	int			retval;
 	unsigned long		page;
 
-	line = tty->index;
-	if ((line < 0) || (line >= NR_PORTS))
-		return -ENODEV;
-	retval = get_async_struct(line, &info);
+	retval = get_async_struct(tty->index, &info);
 	if (retval)
 		return retval;
 	tty->driver_data = info;
@@ -920,7 +917,7 @@ simrs_init (void)
 	if (!ia64_platform_is("hpsim"))
 		return -ENODEV;
 
-	hp_simserial_driver = alloc_tty_driver(1);
+	hp_simserial_driver = alloc_tty_driver(NR_PORTS);
 	if (!hp_simserial_driver)
 		return -ENOMEM;
 

arch/xtensa/platforms/iss/console.c

@@ -68,11 +68,6 @@ static void rs_poll(unsigned long);
 
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
-	int line = tty->index;
-
-	if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES))
-		return -ENODEV;
-
 	spin_lock(&timer_lock);
 
 	if (tty->count == 1) {
@@ -101,6 +96,7 @@ static void rs_close(struct tty_struct *tty, struct file * filp)
 {
 	spin_lock(&timer_lock);
 	if (tty->count == 1)
+		/* this will cause a deadlock if the timer ticks right now */
 		del_timer_sync(&serial_timer);
 	spin_unlock(&timer_lock);
 }
@@ -210,7 +206,7 @@ static const struct tty_operations serial_ops = {
 
 int __init rs_init(void)
 {
-	serial_driver = alloc_tty_driver(1);
+	serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
 
 	printk ("%s %s\n", serial_name, serial_version);
 

drivers/char/pcmcia/synclink_cs.c

@@ -2484,7 +2484,7 @@ static int mgslpc_open(struct tty_struct *tty, struct file * filp)
 
 	/* verify range of specified line number */
 	line = tty->index;
-	if ((line < 0) || (line >= mgslpc_device_count)) {
+	if (line >= mgslpc_device_count) {
 		printk("%s(%d):mgslpc_open with invalid line #%d.\n",
 			__FILE__,__LINE__,line);
 		return -ENODEV;

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)

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);
 }
 

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)) {

drivers/s390/char/con3215.c

@@ -926,13 +926,9 @@ console_initcall(con3215_init);
 static int tty3215_open(struct tty_struct *tty, struct file * filp)
 {
 	struct raw3215_info *raw;
-	int retval, line;
+	int retval;
 
-	line = tty->index;
-	if ((line < 0) || (line >= NR_3215))
-		return -ENODEV;
-
-	raw = raw3215[line];
+	raw = raw3215[tty->index];
 	if (raw == NULL)
 		return -ENODEV;
 

drivers/tty/amiserial.c

@@ -1768,13 +1768,9 @@ static int get_async_struct(int line, struct async_struct **ret_info)
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct async_struct	*info;
-	int 			retval, line;
+	int retval;
 
-	line = tty->index;
-	if ((line < 0) || (line >= NR_PORTS)) {
-		return -ENODEV;
-	}
-	retval = get_async_struct(line, &info);
+	retval = get_async_struct(tty->index, &info);
 	if (retval) {
 		return retval;
 	}
@@ -1964,7 +1960,7 @@ static int __init amiga_serial_probe(struct platform_device *pdev)
 	struct serial_state * state;
 	int error;
 
-	serial_driver = alloc_tty_driver(1);
+	serial_driver = alloc_tty_driver(NR_PORTS);
 	if (!serial_driver)
 		return -ENOMEM;
 

drivers/tty/cyclades.c

@@ -1515,13 +1515,9 @@ static void cy_shutdown(struct cyclades_port *info, struct tty_struct *tty)
 static int cy_open(struct tty_struct *tty, struct file *filp)
 {
 	struct cyclades_port *info;
-	unsigned int i, line;
+	unsigned int i, line = tty->index;
 	int retval;
 
-	line = tty->index;
-	if (tty->index < 0 || NR_PORTS <= line)
-		return -ENODEV;
-
 	for (i = 0; i < NR_CARDS; i++)
 		if (line < cy_card[i].first_line + cy_card[i].nports &&
 				line >= cy_card[i].first_line)

drivers/tty/hvc/hvcs.c

@@ -1090,27 +1090,23 @@ static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address,
  */
 static struct hvcs_struct *hvcs_get_by_index(int index)
 {
-	struct hvcs_struct *hvcsd = NULL;
+	struct hvcs_struct *hvcsd;
 	unsigned long flags;
 
 	spin_lock(&hvcs_structs_lock);
-	/* We can immediately discard OOB requests */
-	if (index >= 0 && index < HVCS_MAX_SERVER_ADAPTERS) {
-		list_for_each_entry(hvcsd, &hvcs_structs, next) {
-			spin_lock_irqsave(&hvcsd->lock, flags);
-			if (hvcsd->index == index) {
-				kref_get(&hvcsd->kref);
-				spin_unlock_irqrestore(&hvcsd->lock, flags);
-				spin_unlock(&hvcs_structs_lock);
-				return hvcsd;
-			}
+	list_for_each_entry(hvcsd, &hvcs_structs, next) {
+		spin_lock_irqsave(&hvcsd->lock, flags);
+		if (hvcsd->index == index) {
+			kref_get(&hvcsd->kref);
 			spin_unlock_irqrestore(&hvcsd->lock, flags);
+			spin_unlock(&hvcs_structs_lock);
+			return hvcsd;
 		}
-		hvcsd = NULL;
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
 	}
-
 	spin_unlock(&hvcs_structs_lock);
-	return hvcsd;
+
+	return NULL;
 }
 
 /*

drivers/tty/hvc/hvsi.c

@@ -737,14 +737,11 @@ static int hvsi_open(struct tty_struct *tty, struct file *filp)
 {
 	struct hvsi_struct *hp;
 	unsigned long flags;
-	int line = tty->index;
 	int ret;
 
 	pr_debug("%s\n", __func__);
 
-	if (line < 0 || line >= hvsi_count)
-		return -ENODEV;
-	hp = &hvsi_ports[line];
+	hp = &hvsi_ports[tty->index];
 
 	tty->driver_data = hp;
 

drivers/tty/isicom.c

@@ -849,8 +849,6 @@ static struct tty_port *isicom_find_port(struct tty_struct *tty)
 	unsigned int board;
 	int line = tty->index;
 
-	if (line < 0 || line > PORT_COUNT-1)
-		return NULL;
 	board = BOARD(line);
 	card = &isi_card[board];
 

drivers/tty/mxser.c

@@ -1010,8 +1010,6 @@ static int mxser_open(struct tty_struct *tty, struct file *filp)
 	line = tty->index;
 	if (line == MXSER_PORTS)
 		return 0;
-	if (line < 0 || line > MXSER_PORTS)
-		return -ENODEV;
 	info = &mxser_boards[line / MXSER_PORTS_PER_BOARD].ports[line % MXSER_PORTS_PER_BOARD];
 	if (!info->ioaddr)
 		return -ENODEV;

drivers/tty/rocket.c

@@ -892,12 +892,12 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
 {
 	struct r_port *info;
 	struct tty_port *port;
-	int line = 0, retval;
+	int retval;
 	CHANNEL_t *cp;
 	unsigned long page;
 
-	line = tty->index;
-	if (line < 0 || line >= MAX_RP_PORTS || ((info = rp_table[line]) == NULL))
+	info = rp_table[tty->index];
+	if (info == NULL)
 		return -ENXIO;
 	port = &info->port;
 	

drivers/tty/serial/68328serial.c

@@ -1190,14 +1190,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
 int rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct m68k_serial	*info;
-	int 			retval, line;
+	int retval;
 
-	line = tty->index;
-	
-	if (line >= NR_PORTS || line < 0) /* we have exactly one */
-		return -ENODEV;
-
-	info = &m68k_soft[line];
+	info = &m68k_soft[tty->index];
 
 	if (serial_paranoia_check(info, tty->name, "rs_open"))
 		return -ENODEV;

drivers/tty/serial/crisv10.c

@@ -4105,20 +4105,11 @@ static int
 rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct e100_serial	*info;
-	int 			retval, line;
+	int 			retval;
 	unsigned long           page;
 	int                     allocated_resources = 0;
 
-	/* find which port we want to open */
-	line = tty->index;
-
-	if (line < 0 || line >= NR_PORTS)
-		return -ENODEV;
-
-	/* find the corresponding e100_serial struct in the table */
-	info = rs_table + line;
-
-	/* don't allow the opening of ports that are not enabled in the HW config */
+	info = rs_table + tty->index;
 	if (!info->enabled)
 		return -ENODEV;
 
@@ -4131,7 +4122,7 @@ rs_open(struct tty_struct *tty, struct file * filp)
 	tty->driver_data = info;
 	info->port.tty = tty;
 
-	info->port.tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+	tty->low_latency = !!(info->flags & ASYNC_LOW_LATENCY);
 
 	if (!tmp_buf) {
 		page = get_zeroed_page(GFP_KERNEL);

drivers/tty/synclink.c

@@ -3381,7 +3381,7 @@ static int mgsl_open(struct tty_struct *tty, struct file * filp)
 
 	/* verify range of specified line number */	
 	line = tty->index;
-	if ((line < 0) || (line >= mgsl_device_count)) {
+	if (line >= mgsl_device_count) {
 		printk("%s(%d):mgsl_open with invalid line #%d.\n",
 			__FILE__,__LINE__,line);
 		return -ENODEV;

drivers/tty/synclink_gt.c

@@ -654,7 +654,7 @@ static int open(struct tty_struct *tty, struct file *filp)
 	unsigned long flags;
 
 	line = tty->index;
-	if ((line < 0) || (line >= slgt_device_count)) {
+	if (line >= slgt_device_count) {
 		DBGERR(("%s: open with invalid line #%d.\n", driver_name, line));
 		return -ENODEV;
 	}

drivers/tty/synclinkmp.c

@@ -721,7 +721,7 @@ static int open(struct tty_struct *tty, struct file *filp)
 	unsigned long flags;
 
 	line = tty->index;
-	if ((line < 0) || (line >= synclinkmp_device_count)) {
+	if (line >= synclinkmp_device_count) {
 		printk("%s(%d): open with invalid line #%d.\n",
 			__FILE__,__LINE__,line);
 		return -ENODEV;

drivers/usb/gadget/u_serial.c

@@ -725,9 +725,6 @@ static int gs_open(struct tty_struct *tty, struct file *file)
 	struct gs_port	*port;
 	int		status;
 
-	if (port_num < 0 || port_num >= n_ports)
-		return -ENXIO;
-
 	do {
 		mutex_lock(&ports[port_num].lock);
 		port = ports[port_num].port;

net/irda/ircomm/ircomm_tty.c

@@ -365,16 +365,12 @@ static int ircomm_tty_block_til_ready(struct ircomm_tty_cb *self,
 static int ircomm_tty_open(struct tty_struct *tty, struct file *filp)
 {
 	struct ircomm_tty_cb *self;
-	unsigned int line;
+	unsigned int line = tty->index;
 	unsigned long	flags;
 	int ret;
 
 	IRDA_DEBUG(2, "%s()\n", __func__ );
 
-	line = tty->index;
-	if (line >= IRCOMM_TTY_PORTS)
-		return -ENODEV;
-
 	/* Check if instance already exists */
 	self = hashbin_lock_find(ircomm_tty, line, NULL);
 	if (!self) {