tty: Make tiocgicount a handler

commit d281da7ff6f70efca0553c288bb883e8605b3862 upstream

Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.

This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 53ffcfc1154bef0b72f33fc362905c5a6c250d35..123cedf62ccef7741576cfe9e8b542e212a09916 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -96,6 +96,7 @@
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/seq_file.h>
+#include <linux/serial.h>
 
 #include <linux/uaccess.h>
 #include <asm/system.h>
@@ -2436,6 +2437,20 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
        return tty->ops->tiocmset(tty, file, set, clear);
 }
 
+static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
+{
+       int retval = -EINVAL;
+       struct serial_icounter_struct icount;
+       memset(&icount, 0, sizeof(icount));
+       if (tty->ops->get_icount)
+               retval = tty->ops->get_icount(tty, &icount);
+       if (retval != 0)
+               return retval;
+       if (copy_to_user(arg, &icount, sizeof(icount)))
+               return -EFAULT;
+       return 0;
+}
+
 struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
 {
        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
@@ -2556,6 +2571,12 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        case TIOCMBIC:
        case TIOCMBIS:
                return tty_tiocmset(tty, file, cmd, p);
+       case TIOCGICOUNT:
+               retval = tty_tiocgicount(tty, p);
+               /* For the moment allow fall through to the old method */
+               if (retval != -EINVAL)
+                       return retval;
+               break;
        case TCFLSH:
                switch (arg) {
                case TCIFLUSH:

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index dcc72444e8e7015e904c70d726a83873dbeff21e..772d9d81ddd12afbb12c4c7161750c81870ebda5 100644 (file)
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1067,10 +1067,10 @@ uart_wait_modem_status(struct uart_state *state, unsigned long arg)
  * NB: both 1->0 and 0->1 transitions are counted except for
  *     RI where only 0->1 is counted.
  */
-static int uart_get_count(struct uart_state *state,
-                         struct serial_icounter_struct __user *icnt)
+static int uart_get_icount(struct tty_struct *tty,
+                         struct serial_icounter_struct *icount)
 {
-       struct serial_icounter_struct icount;
+       struct uart_state *state = tty->driver_data;
        struct uart_icount cnow;
        struct uart_port *uport = state->uart_port;
 
@@ -1078,19 +1078,19 @@ static int uart_get_count(struct uart_state *state,
        memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
        spin_unlock_irq(&uport->lock);
 
-       icount.cts         = cnow.cts;
-       icount.dsr         = cnow.dsr;
-       icount.rng         = cnow.rng;
-       icount.dcd         = cnow.dcd;
-       icount.rx          = cnow.rx;
-       icount.tx          = cnow.tx;
-       icount.frame       = cnow.frame;
-       icount.overrun     = cnow.overrun;
-       icount.parity      = cnow.parity;
-       icount.brk         = cnow.brk;
-       icount.buf_overrun = cnow.buf_overrun;
+       icount->cts         = cnow.cts;
+       icount->dsr         = cnow.dsr;
+       icount->rng         = cnow.rng;
+       icount->dcd         = cnow.dcd;
+       icount->rx          = cnow.rx;
+       icount->tx          = cnow.tx;
+       icount->frame       = cnow.frame;
+       icount->overrun     = cnow.overrun;
+       icount->parity      = cnow.parity;
+       icount->brk         = cnow.brk;
+       icount->buf_overrun = cnow.buf_overrun;
 
-       return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
+       return 0;
 }
 
 /*
@@ -1143,10 +1143,6 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
        case TIOCMIWAIT:
                ret = uart_wait_modem_status(state, arg);
                break;
-
-       case TIOCGICOUNT:
-               ret = uart_get_count(state, uarg);
-               break;
        }
 
        if (ret != -ENOIOCTLCMD)
@@ -2322,6 +2318,7 @@ static const struct tty_operations uart_ops = {
 #endif
        .tiocmget       = uart_tiocmget,
        .tiocmset       = uart_tiocmset,
+       .get_icount     = uart_get_icount,
 #ifdef CONFIG_CONSOLE_POLL
        .poll_init      = uart_poll_init,
        .poll_get_char  = uart_poll_get_char,

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index bd3fa7ff15b12166bf0cf2ad86f3214144f914c0..f23f3b47ac166f48020a748040945cfac3825ab0 100644 (file)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -562,6 +562,18 @@ static int serial_tiocmset(struct tty_struct *tty, struct file *file,
        return -EINVAL;
 }
 
+static int serial_get_icount(struct tty_struct *tty,
+                               struct serial_icounter_struct *icount)
+{
+       struct usb_serial_port *port = tty->driver_data;
+
+       dbg("%s - port %d", __func__, port->number);
+
+       if (port->serial->type->get_icount)
+               return port->serial->type->get_icount(tty, icount);
+       return -EINVAL;
+}
+
 /*
  * We would be calling tty_wakeup here, but unfortunately some line
  * disciplines have an annoying habit of calling tty->write from
@@ -1214,6 +1226,7 @@ static const struct tty_operations serial_ops = {
        .chars_in_buffer =      serial_chars_in_buffer,
        .tiocmget =             serial_tiocmget,
        .tiocmset =             serial_tiocmset,
+       .get_icount =           serial_get_icount,
        .cleanup =              serial_cleanup,
        .install =              serial_install,
        .proc_fops =            &serial_proc_fops,

diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index b086779825252b40612062391dad9c67c3912ddf..db2d227694da664f2e789767927da0126de7c64d 100644 (file)
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -224,6 +224,12 @@
  *     unless the tty also has a valid tty->termiox pointer.
  *
  *     Optional: Called under the termios lock
+ *
+ * int (*get_icount)(struct tty_struct *tty, struct serial_icounter *icount);
+ *
+ *     Called when the device receives a TIOCGICOUNT ioctl. Passed a kernel
+ *     structure to complete. This method is optional and will only be called
+ *     if provided (otherwise EINVAL will be returned).
  */
 
 #include <linux/fs.h>
@@ -232,6 +238,7 @@
 
 struct tty_struct;
 struct tty_driver;
+struct serial_icounter_struct;
 
 struct tty_operations {
        struct tty_struct * (*lookup)(struct tty_driver *driver,
@@ -268,6 +275,8 @@ struct tty_operations {
                        unsigned int set, unsigned int clear);
        int (*resize)(struct tty_struct *tty, struct winsize *ws);
        int (*set_termiox)(struct tty_struct *tty, struct termiox *tnew);
+       int (*get_icount)(struct tty_struct *tty,
+                               struct serial_icounter_struct *icount);
 #ifdef CONFIG_CONSOLE_POLL
        int (*poll_init)(struct tty_driver *driver, int line, char *options);
        int (*poll_get_char)(struct tty_driver *driver, int line);

diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index bb911e3c636c4adcdf889f5d33ec6395862f1297..78670cbbfdc7281ff8ce5d86e0c9b9c8a98d938a 100644 (file)
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -259,6 +259,8 @@ struct usb_serial_driver {
        int  (*tiocmget)(struct tty_struct *tty, struct file *file);
        int  (*tiocmset)(struct tty_struct *tty, struct file *file,
                         unsigned int set, unsigned int clear);
+       int  (*get_icount)(struct tty_struct *tty,
+                       struct serial_icounter_struct *icount);
        /* Called by the tty layer for port level work. There may or may not
           be an attached tty at this point */
        void (*dtr_rts)(struct usb_serial_port *port, int on);