staging: dgnc: audit goto's in dgnc_tty

TODO file requests fix up of error handling.

Audit dgnc_mgmt.c and fix all return paths to be uniform and inline
with kernel coding style.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/dgnc/dgnc_tty.c b/drivers/staging/dgnc/dgnc_tty.c
index cde00e3702fac1003d98c161bd9f6af3ecec176c..ffbe5a22169f5bef4ba95075cc3f1d29b3eb2e67 100644 (file)
--- a/drivers/staging/dgnc/dgnc_tty.c
+++ b/drivers/staging/dgnc/dgnc_tty.c
@@ -143,7 +143,6 @@ int dgnc_tty_register(struct dgnc_board *brd)
                                              TTY_DRIVER_REAL_RAW |
                                              TTY_DRIVER_DYNAMIC_DEV |
                                              TTY_DRIVER_HARDWARE_BREAK);
-
        if (IS_ERR(brd->serial_driver))
                return PTR_ERR(brd->serial_driver);
 
@@ -181,7 +180,6 @@ int dgnc_tty_register(struct dgnc_board *brd)
                                             TTY_DRIVER_REAL_RAW |
                                             TTY_DRIVER_DYNAMIC_DEV |
                                             TTY_DRIVER_HARDWARE_BREAK);
-
        if (IS_ERR(brd->print_driver)) {
                rc = PTR_ERR(brd->print_driver);
                goto unregister_serial_driver;
@@ -220,7 +218,6 @@ int dgnc_tty_register(struct dgnc_board *brd)
        tty_unregister_driver(brd->serial_driver);
 free_serial_driver:
        put_tty_driver(brd->serial_driver);
-
        return rc;
 }
 
@@ -241,6 +238,7 @@ void dgnc_tty_unregister(struct dgnc_board *brd)
 int dgnc_tty_init(struct dgnc_board *brd)
 {
        int i;
+       int rc;
        void __iomem *vaddr;
        struct channel_t *ch;
 
@@ -260,8 +258,10 @@ int dgnc_tty_init(struct dgnc_board *brd)
                 */
                brd->channels[i] = kzalloc(sizeof(*brd->channels[i]),
                                           GFP_KERNEL);
-               if (!brd->channels[i])
+               if (!brd->channels[i]) {
+                       rc = -ENOMEM;
                        goto err_free_channels;
+               }
        }
 
        ch = brd->channels[0];
@@ -319,7 +319,7 @@ int dgnc_tty_init(struct dgnc_board *brd)
                kfree(brd->channels[i]);
                brd->channels[i] = NULL;
        }
-       return -ENOMEM;
+       return rc;
 }
 
 /*
@@ -914,7 +914,6 @@ static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
         */
        rc = wait_event_interruptible(brd->state_wait,
                                      (brd->state & BOARD_READY));
-
        if (rc)
                return rc;
 
@@ -922,14 +921,14 @@ static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
 
        /* If opened device is greater than our number of ports, bail. */
        if (PORT_NUM(minor) >= brd->nasync) {
-               spin_unlock_irqrestore(&brd->bd_lock, flags);
-               return -ENXIO;
+               rc = -ENXIO;
+               goto err_brd_unlock;
        }
 
        ch = brd->channels[PORT_NUM(minor)];
        if (!ch) {
-               spin_unlock_irqrestore(&brd->bd_lock, flags);
-               return -ENXIO;
+               rc = -ENXIO;
+               goto err_brd_unlock;
        }
 
        /* Drop board lock */
@@ -946,8 +945,8 @@ static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
                un = &brd->channels[PORT_NUM(minor)]->ch_pun;
                un->un_type = DGNC_PRINT;
        } else {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return -ENXIO;
+               rc = -ENXIO;
+               goto err_ch_unlock;
        }
 
        /*
@@ -959,7 +958,6 @@ static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
 
        rc = wait_event_interruptible(ch->ch_flags_wait,
                                      ((ch->ch_flags & CH_OPENING) == 0));
-
        /* If ret is non-zero, user ctrl-c'ed us */
        if (rc)
                return -EINTR;
@@ -975,7 +973,6 @@ static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
                                ch->ch_flags_wait,
                                (((ch->ch_tun.un_flags |
                                ch->ch_pun.un_flags) & UN_CLOSING) == 0));
-
        /* If ret is non-zero, user ctrl-c'ed us */
        if (rc)
                return -EINTR;
@@ -1014,7 +1011,6 @@ static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
                kfree(ch->ch_rqueue);
                kfree(ch->ch_equeue);
                kfree(ch->ch_wqueue);
-
                return -ENOMEM;
        }
 
@@ -1082,6 +1078,14 @@ static int dgnc_tty_open(struct tty_struct *tty, struct file *file)
        spin_unlock_irqrestore(&ch->ch_lock, flags);
 
        return rc;
+
+err_brd_unlock:
+       spin_unlock_irqrestore(&brd->bd_lock, flags);
+       return rc;
+err_ch_unlock:
+       spin_unlock_irqrestore(&ch->ch_lock, flags);
+       return rc;
+
 }
 
 /*
@@ -1093,7 +1097,7 @@ static int dgnc_block_til_ready(struct tty_struct *tty,
                                struct file *file,
                                struct channel_t *ch)
 {
-       int retval = 0;
+       int rc = 0;
        struct un_t *un = tty->driver_data;
        unsigned long flags;
        uint    old_flags = 0;
@@ -1115,13 +1119,13 @@ static int dgnc_block_til_ready(struct tty_struct *tty,
                 * bail with error.
                 */
                if (ch->ch_bd->state == BOARD_FAILED) {
-                       retval = -ENXIO;
+                       rc = -ENXIO;
                        break;
                }
 
                /* If tty was hung up, break out of loop and set error. */
                if (tty_hung_up_p(file)) {
-                       retval = -EAGAIN;
+                       rc = -EAGAIN;
                        break;
                }
 
@@ -1146,7 +1150,7 @@ static int dgnc_block_til_ready(struct tty_struct *tty,
                                break;
 
                        if (tty_io_error(tty)) {
-                               retval = -EIO;
+                               rc = -EIO;
                                break;
                        }
 
@@ -1165,7 +1169,7 @@ static int dgnc_block_til_ready(struct tty_struct *tty,
                 * Leave loop with error set.
                 */
                if (signal_pending(current)) {
-                       retval = -ERESTARTSYS;
+                       rc = -ERESTARTSYS;
                        break;
                }
 
@@ -1189,12 +1193,12 @@ static int dgnc_block_til_ready(struct tty_struct *tty,
                 * from the current value.
                 */
                if (sleep_on_un_flags)
-                       retval = wait_event_interruptible
+                       rc = wait_event_interruptible
                                (un->un_flags_wait,
                                 (old_flags != (ch->ch_tun.un_flags |
                                                ch->ch_pun.un_flags)));
                else
-                       retval = wait_event_interruptible(
+                       rc = wait_event_interruptible(
                                        ch->ch_flags_wait,
                                        (old_flags != ch->ch_flags));
 
@@ -1208,8 +1212,7 @@ static int dgnc_block_til_ready(struct tty_struct *tty,
        ch->ch_wopen--;
 
        spin_unlock_irqrestore(&ch->ch_lock, flags);
-
-       return retval;
+       return rc;
 }
 
 /*
@@ -1375,7 +1378,7 @@ static int dgnc_tty_chars_in_buffer(struct tty_struct *tty)
        ushort thead;
        ushort ttail;
        uint tmask;
-       uint chars = 0;
+       uint chars;
        unsigned long flags;
 
        if (!tty)
@@ -1397,16 +1400,14 @@ static int dgnc_tty_chars_in_buffer(struct tty_struct *tty)
 
        spin_unlock_irqrestore(&ch->ch_lock, flags);
 
-       if (ttail == thead) {
+       if (ttail == thead)
                chars = 0;
-       } else {
-               if (thead >= ttail)
-                       chars = thead - ttail;
-               else
-                       chars = thead - ttail + WQUEUESIZE;
-       }
+       else if (thead > ttail)
+               chars = thead - ttail;
+       else
+               chars = thead - ttail + WQUEUESIZE;
 
-       return chars;
+       return (int)chars;
 }
 
 /*
@@ -1419,6 +1420,8 @@ static int dgnc_tty_chars_in_buffer(struct tty_struct *tty)
  */
 static int dgnc_maxcps_room(struct channel_t *ch, int bytes_available)
 {
+       int rc = bytes_available;
+
        if (ch->ch_digi.digi_maxcps > 0 && ch->ch_digi.digi_bufsize > 0) {
                int cps_limit = 0;
                unsigned long current_time = jiffies;
@@ -1439,16 +1442,16 @@ static int dgnc_maxcps_room(struct channel_t *ch, int bytes_available)
                        cps_limit = 0;
                }
 
-               bytes_available = min(cps_limit, bytes_available);
+               rc = min(cps_limit, bytes_available);
        }
 
-       return bytes_available;
+       return rc;
 }
 
 /*
  * dgnc_tty_write_room()
  *
- * Return space available in Tx buffer
+ * Return room available in Tx buffer
  */
 static int dgnc_tty_write_room(struct tty_struct *tty)
 {
@@ -1457,7 +1460,7 @@ static int dgnc_tty_write_room(struct tty_struct *tty)
        ushort head;
        ushort tail;
        ushort tmask;
-       int ret = 0;
+       int room = 0;
        unsigned long flags;
 
        if (!tty)
@@ -1477,33 +1480,32 @@ static int dgnc_tty_write_room(struct tty_struct *tty)
        head = (ch->ch_w_head) & tmask;
        tail = (ch->ch_w_tail) & tmask;
 
-       ret = tail - head - 1;
-       if (ret < 0)
-               ret += WQUEUESIZE;
+       room = tail - head - 1;
+       if (room < 0)
+               room += WQUEUESIZE;
 
        /* Limit printer to maxcps */
        if (un->un_type != DGNC_PRINT)
-               ret = dgnc_maxcps_room(ch, ret);
+               room = dgnc_maxcps_room(ch, room);
 
        /*
-        * If we are printer device, leave space for
+        * If we are printer device, leave room for
         * possibly both the on and off strings.
         */
        if (un->un_type == DGNC_PRINT) {
                if (!(ch->ch_flags & CH_PRON))
-                       ret -= ch->ch_digi.digi_onlen;
-               ret -= ch->ch_digi.digi_offlen;
+                       room -= ch->ch_digi.digi_onlen;
+               room -= ch->ch_digi.digi_offlen;
        } else {
                if (ch->ch_flags & CH_PRON)
-                       ret -= ch->ch_digi.digi_offlen;
+                       room -= ch->ch_digi.digi_offlen;
        }
 
-       if (ret < 0)
-               ret = 0;
+       if (room < 0)
+               room = 0;
 
        spin_unlock_irqrestore(&ch->ch_lock, flags);
-
-       return ret;
+       return room;
 }
 
 /*
@@ -1657,7 +1659,6 @@ static int dgnc_tty_write(struct tty_struct *tty,
        return count;
 
 exit_retry:
-
        spin_unlock_irqrestore(&ch->ch_lock, flags);
        return 0;
 }
@@ -1668,20 +1669,20 @@ static int dgnc_tty_tiocmget(struct tty_struct *tty)
 {
        struct channel_t *ch;
        struct un_t *un;
-       int result = -EIO;
+       int rc = -EIO;
        unsigned char mstat = 0;
        unsigned long flags;
 
        if (!tty || tty->magic != TTY_MAGIC)
-               return result;
+               return rc;
 
        un = tty->driver_data;
        if (!un || un->magic != DGNC_UNIT_MAGIC)
-               return result;
+               return rc;
 
        ch = un->un_ch;
        if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
-               return result;
+               return rc;
 
        spin_lock_irqsave(&ch->ch_lock, flags);
 
@@ -1689,22 +1690,22 @@ static int dgnc_tty_tiocmget(struct tty_struct *tty)
 
        spin_unlock_irqrestore(&ch->ch_lock, flags);
 
-       result = 0;
+       rc = 0;
 
        if (mstat & UART_MCR_DTR)
-               result |= TIOCM_DTR;
+               rc |= TIOCM_DTR;
        if (mstat & UART_MCR_RTS)
-               result |= TIOCM_RTS;
+               rc |= TIOCM_RTS;
        if (mstat & UART_MSR_CTS)
-               result |= TIOCM_CTS;
+               rc |= TIOCM_CTS;
        if (mstat & UART_MSR_DSR)
-               result |= TIOCM_DSR;
+               rc |= TIOCM_DSR;
        if (mstat & UART_MSR_RI)
-               result |= TIOCM_RI;
+               rc |= TIOCM_RI;
        if (mstat & UART_MSR_DCD)
-               result |= TIOCM_CD;
+               rc |= TIOCM_CD;
 
-       return result;
+       return rc;
 }
 
 /*
@@ -1719,23 +1720,23 @@ static int dgnc_tty_tiocmset(struct tty_struct *tty,
        struct dgnc_board *bd;
        struct channel_t *ch;
        struct un_t *un;
-       int ret = -EIO;
+       int rc = -EIO;
        unsigned long flags;
 
        if (!tty || tty->magic != TTY_MAGIC)
-               return ret;
+               return rc;
 
        un = tty->driver_data;
        if (!un || un->magic != DGNC_UNIT_MAGIC)
-               return ret;
+               return rc;
 
        ch = un->un_ch;
        if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
-               return ret;
+               return rc;
 
        bd = ch->ch_bd;
        if (!bd || bd->magic != DGNC_BOARD_MAGIC)
-               return ret;
+               return rc;
 
        spin_lock_irqsave(&ch->ch_lock, flags);
 
@@ -1768,23 +1769,23 @@ static int dgnc_tty_send_break(struct tty_struct *tty, int msec)
        struct dgnc_board *bd;
        struct channel_t *ch;
        struct un_t *un;
-       int ret = -EIO;
+       int rc = -EIO;
        unsigned long flags;
 
        if (!tty || tty->magic != TTY_MAGIC)
-               return ret;
+               return rc;
 
        un = tty->driver_data;
        if (!un || un->magic != DGNC_UNIT_MAGIC)
-               return ret;
+               return rc;
 
        ch = un->un_ch;
        if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
-               return ret;
+               return rc;
 
        bd = ch->ch_bd;
        if (!bd || bd->magic != DGNC_BOARD_MAGIC)
-               return ret;
+               return rc;
 
        switch (msec) {
        case -1:
@@ -1876,11 +1877,11 @@ static void dgnc_tty_send_xchar(struct tty_struct *tty, char c)
 static inline int dgnc_get_mstat(struct channel_t *ch)
 {
        unsigned char mstat;
-       int result = 0;
+       int rc = -ENXIO;
        unsigned long flags;
 
        if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
-               return -ENXIO;
+               return rc;
 
        spin_lock_irqsave(&ch->ch_lock, flags);
 
@@ -1888,20 +1889,22 @@ static inline int dgnc_get_mstat(struct channel_t *ch)
 
        spin_unlock_irqrestore(&ch->ch_lock, flags);
 
+       rc = 0;
+
        if (mstat & UART_MCR_DTR)
-               result |= TIOCM_DTR;
+               rc |= TIOCM_DTR;
        if (mstat & UART_MCR_RTS)
-               result |= TIOCM_RTS;
+               rc |= TIOCM_RTS;
        if (mstat & UART_MSR_CTS)
-               result |= TIOCM_CTS;
+               rc |= TIOCM_CTS;
        if (mstat & UART_MSR_DSR)
-               result |= TIOCM_DSR;
+               rc |= TIOCM_DSR;
        if (mstat & UART_MSR_RI)
-               result |= TIOCM_RI;
+               rc |= TIOCM_RI;
        if (mstat & UART_MSR_DCD)
-               result |= TIOCM_CD;
+               rc |= TIOCM_CD;
 
-       return result;
+       return rc;
 }
 
 /* Return modem signals to ld. */
@@ -1921,13 +1924,13 @@ static int dgnc_set_modem_info(struct channel_t *ch,
                               unsigned int command,
                               unsigned int __user *value)
 {
-       int ret = -ENXIO;
+       int rc;
        unsigned int arg = 0;
        unsigned long flags;
 
-       ret = get_user(arg, value);
-       if (ret)
-               return ret;
+       rc = get_user(arg, value);
+       if (rc)
+               return rc;
 
        switch (command) {
        case TIOCMBIS:
@@ -1987,20 +1990,21 @@ static int dgnc_tty_digigeta(struct tty_struct *tty,
        struct un_t *un;
        struct digi_t tmp;
        unsigned long flags;
+       int rc = -EFAULT;
 
        if (!retinfo)
-               return -EFAULT;
+               return rc;
 
        if (!tty || tty->magic != TTY_MAGIC)
-               return -EFAULT;
+               return rc;
 
        un = tty->driver_data;
        if (!un || un->magic != DGNC_UNIT_MAGIC)
-               return -EFAULT;
+               return rc;
 
        ch = un->un_ch;
        if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
-               return -EFAULT;
+               return rc;
 
        memset(&tmp, 0, sizeof(tmp));
 
@@ -2009,7 +2013,7 @@ static int dgnc_tty_digigeta(struct tty_struct *tty,
        spin_unlock_irqrestore(&ch->ch_lock, flags);
 
        if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
-               return -EFAULT;
+               return rc;
 
        return 0;
 }
@@ -2027,24 +2031,25 @@ static int dgnc_tty_digiseta(struct tty_struct *tty,
        struct un_t *un;
        struct digi_t new_digi;
        unsigned long flags;
+       int rc = -EFAULT;
 
        if (!tty || tty->magic != TTY_MAGIC)
-               return -EFAULT;
+               return rc;
 
        un = tty->driver_data;
        if (!un || un->magic != DGNC_UNIT_MAGIC)
-               return -EFAULT;
+               return rc;
 
        ch = un->un_ch;
        if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
-               return -EFAULT;
+               return rc;
 
        bd = ch->ch_bd;
        if (!bd || bd->magic != DGNC_BOARD_MAGIC)
-               return -EFAULT;
+               return rc;
 
        if (copy_from_user(&new_digi, new_info, sizeof(new_digi)))
-               return -EFAULT;
+               return rc;
 
        spin_lock_irqsave(&ch->ch_lock, flags);
 
@@ -2353,32 +2358,32 @@ static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
        struct board_ops *ch_bd_ops;
        struct channel_t *ch;
        struct un_t *un;
-       int rc;
+       int rc = -ENODEV;
        unsigned long flags;
        void __user *uarg = (void __user *)arg;
 
        if (!tty || tty->magic != TTY_MAGIC)
-               return -ENODEV;
+               return rc;
 
        un = tty->driver_data;
        if (!un || un->magic != DGNC_UNIT_MAGIC)
-               return -ENODEV;
+               return rc;
 
        ch = un->un_ch;
        if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
-               return -ENODEV;
+               return rc;
 
        bd = ch->ch_bd;
        if (!bd || bd->magic != DGNC_BOARD_MAGIC)
-               return -ENODEV;
+               return rc;
 
        ch_bd_ops = bd->bd_ops;
 
        spin_lock_irqsave(&ch->ch_lock, flags);
 
        if (un->un_open_count <= 0) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return -EIO;
+               rc = -EIO;
+               goto err_unlock;
        }
 
        switch (cmd) {
@@ -2504,10 +2509,8 @@ static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
                 * also.
                 */
                rc = tty_check_change(tty);
-               if (rc) {
-                       spin_unlock_irqrestore(&ch->ch_lock, flags);
-                       return rc;
-               }
+               if (rc)
+                       goto err_unlock;
 
                if ((arg == TCIFLUSH) || (arg == TCIOFLUSH)) {
                        ch->ch_r_head = ch->ch_r_tail;
@@ -2588,7 +2591,6 @@ static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
                if (cmd == (DIGI_SETAW)) {
                        spin_unlock_irqrestore(&ch->ch_lock, flags);
                        rc = ch_bd_ops->drain(tty, 0);
-
                        if (rc)
                                return -EINTR;
 
@@ -2787,4 +2789,7 @@ static int dgnc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
 
                return -ENOIOCTLCMD;
        }
+err_unlock:
+       spin_unlock_irqrestore(&ch->ch_lock, flags);
+       return rc;
 }