drivers/char/mem.c: avoid OOM lockup during large reads from /dev/zero

[safe/jmp/linux-2.6] / drivers / char / riscom8.c

diff --git a/drivers/char/riscom8.c b/drivers/char/riscom8.c
index af34c20..2176604 100644 (file)
--- a/drivers/char/riscom8.c
+++ b/drivers/char/riscom8.c
@@ -48,6 +48,7 @@
 #include <linux/delay.h>
 #include <linux/tty_flip.h>
 #include <linux/spinlock.h>
+#include <linux/device.h>
 
 #include <linux/uaccess.h>
 
@@ -906,7 +907,7 @@ static int rc_open(struct tty_struct *tty, struct file *filp)
 
 static void rc_flush_buffer(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        unsigned long flags;
 
        if (rc_paranoia_check(port, tty->name, "rc_flush_buffer"))
@@ -921,7 +922,7 @@ static void rc_flush_buffer(struct tty_struct *tty)
 
 static void rc_close(struct tty_struct *tty, struct file *filp)
 {
-       struct riscom_port *port = (struct riscom_port *) tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        unsigned long flags;
        unsigned long timeout;
@@ -929,35 +930,11 @@ static void rc_close(struct tty_struct *tty, struct file *filp)
        if (!port || rc_paranoia_check(port, tty->name, "close"))
                return;
 
-       spin_lock_irqsave(&port->port.lock, flags);
-
-       if (tty_hung_up_p(filp))
-               goto out;
-
        bp = port_Board(port);
-       if ((tty->count == 1) && (port->port.count != 1))  {
-               printk(KERN_INFO "rc%d: rc_close: bad port count;"
-                      " tty->count is 1, port count is %d\n",
-                      board_No(bp), port->port.count);
-               port->port.count = 1;
-       }
-       if (--port->port.count < 0)  {
-               printk(KERN_INFO "rc%d: rc_close: bad port count "
-                                "for tty%d: %d\n",
-                      board_No(bp), port_No(port), port->port.count);
-               port->port.count = 0;
-       }
-       if (port->port.count)
-               goto out;
-       port->port.flags |= ASYNC_CLOSING;
-       /*
-        * Now we wait for the transmit buffer to clear; and we notify
-        * the line discipline to only process XON/XOFF characters.
-        */
-       tty->closing = 1;
-       spin_unlock_irqrestore(&port->port.lock, flags);
-       if (port->port.closing_wait != ASYNC_CLOSING_WAIT_NONE)
-               tty_wait_until_sent(tty, port->port.closing_wait);
+       
+       if (tty_port_close_start(&port->port, tty, filp) == 0)
+               return;
+       
        /*
         * At this point we stop accepting input.  To do this, we
         * disable the receive line status interrupts, and tell the
@@ -989,29 +966,14 @@ static void rc_close(struct tty_struct *tty, struct file *filp)
        rc_shutdown_port(tty, bp, port);
        rc_flush_buffer(tty);
        spin_unlock_irqrestore(&riscom_lock, flags);
-       tty_ldisc_flush(tty);
 
-       spin_lock_irqsave(&port->port.lock, flags);
-       tty->closing = 0;
-       port->port.tty = NULL;
-       if (port->port.blocked_open) {
-               spin_unlock_irqrestore(&port->port.lock, flags);
-               if (port->port.close_delay)
-                       msleep_interruptible(jiffies_to_msecs(port->port.close_delay));
-               wake_up_interruptible(&port->port.open_wait);
-               spin_lock_irqsave(&port->port.lock, flags);
-       }
-       port->port.flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
-       wake_up_interruptible(&port->port.close_wait);
-
-out:
-       spin_unlock_irqrestore(&riscom_lock, flags);
+       tty_port_close_end(&port->port, tty);
 }
 
 static int rc_write(struct tty_struct *tty,
                    const unsigned char *buf, int count)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        int c, total = 0;
        unsigned long flags;
@@ -1054,7 +1016,7 @@ static int rc_write(struct tty_struct *tty,
 
 static int rc_put_char(struct tty_struct *tty, unsigned char ch)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        unsigned long flags;
        int ret = 0;
 
@@ -1078,7 +1040,7 @@ out:
 
 static void rc_flush_chars(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        unsigned long flags;
 
        if (rc_paranoia_check(port, tty->name, "rc_flush_chars"))
@@ -1098,7 +1060,7 @@ static void rc_flush_chars(struct tty_struct *tty)
 
 static int rc_write_room(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        int     ret;
 
        if (rc_paranoia_check(port, tty->name, "rc_write_room"))
@@ -1112,7 +1074,7 @@ static int rc_write_room(struct tty_struct *tty)
 
 static int rc_chars_in_buffer(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
 
        if (rc_paranoia_check(port, tty->name, "rc_chars_in_buffer"))
                return 0;
@@ -1122,7 +1084,7 @@ static int rc_chars_in_buffer(struct tty_struct *tty)
 
 static int rc_tiocmget(struct tty_struct *tty, struct file *file)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        unsigned char status;
        unsigned int result;
@@ -1152,7 +1114,7 @@ static int rc_tiocmget(struct tty_struct *tty, struct file *file)
 static int rc_tiocmset(struct tty_struct *tty, struct file *file,
                       unsigned int set, unsigned int clear)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        unsigned long flags;
        struct riscom_board *bp;
 
@@ -1184,7 +1146,7 @@ static int rc_tiocmset(struct tty_struct *tty, struct file *file,
 
 static int rc_send_break(struct tty_struct *tty, int length)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp = port_Board(port);
        unsigned long flags;
 
@@ -1277,7 +1239,7 @@ static int rc_get_serial_info(struct riscom_port *port,
 static int rc_ioctl(struct tty_struct *tty, struct file *filp,
                    unsigned int cmd, unsigned long arg)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        void __user *argp = (void __user *)arg;
        int retval;
 
@@ -1303,7 +1265,7 @@ static int rc_ioctl(struct tty_struct *tty, struct file *filp,
 
 static void rc_throttle(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        unsigned long flags;
 
@@ -1325,7 +1287,7 @@ static void rc_throttle(struct tty_struct *tty)
 
 static void rc_unthrottle(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        unsigned long flags;
 
@@ -1347,7 +1309,7 @@ static void rc_unthrottle(struct tty_struct *tty)
 
 static void rc_stop(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        unsigned long flags;
 
@@ -1365,7 +1327,7 @@ static void rc_stop(struct tty_struct *tty)
 
 static void rc_start(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        unsigned long flags;
 
@@ -1386,7 +1348,7 @@ static void rc_start(struct tty_struct *tty)
 
 static void rc_hangup(struct tty_struct *tty)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        struct riscom_board *bp;
        unsigned long flags;
 
@@ -1407,7 +1369,7 @@ static void rc_hangup(struct tty_struct *tty)
 static void rc_set_termios(struct tty_struct *tty,
                                        struct ktermios *old_termios)
 {
-       struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+       struct riscom_port *port = tty->driver_data;
        unsigned long flags;
 
        if (rc_paranoia_check(port, tty->name, "rc_set_termios"))
@@ -1563,6 +1525,7 @@ module_param(iobase2, int, 0);
 module_param(iobase3, int, 0);
 
 MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(RISCOM8_NORMAL_MAJOR);
 #endif /* MODULE */
 
 /*