vserver 1.9.5.x5
[linux-2.6.git] / drivers / char / tty_ioctl.c
index 81eff0d..5859799 100644 (file)
@@ -19,9 +19,9 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/module.h>
+#include <linux/bitops.h>
 
 #include <asm/io.h>
-#include <asm/bitops.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
@@ -98,8 +98,17 @@ static void change_termios(struct tty_struct * tty, struct termios * new_termios
 {
        int canon_change;
        struct termios old_termios = *tty->termios;
+       struct tty_ldisc *ld;
+       
+       /*
+        *      Perform the actual termios internal changes under lock.
+        */
+        
+
+       /* FIXME: we need to decide on some locking/ordering semantics
+          for the set_termios notification eventually */
+       down(&tty->termios_sem);
 
-       local_irq_disable(); // FIXME: is this safe?
        *tty->termios = *new_termios;
        unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
        canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
@@ -109,12 +118,13 @@ static void change_termios(struct tty_struct * tty, struct termios * new_termios
                tty->canon_data = 0;
                tty->erasing = 0;
        }
-       local_irq_enable(); // FIXME: is this safe?
+       
+       
        if (canon_change && !L_ICANON(tty) && tty->read_cnt)
                /* Get characters left over from canonical mode. */
                wake_up_interruptible(&tty->read_wait);
 
-       /* see if packet mode change of state */
+       /* See if packet mode change of state. */
 
        if (tty->link && tty->link->packet) {
                int old_flow = ((old_termios.c_iflag & IXON) &&
@@ -132,17 +142,23 @@ static void change_termios(struct tty_struct * tty, struct termios * new_termios
                        wake_up_interruptible(&tty->link->read_wait);
                }
        }
-
+          
        if (tty->driver->set_termios)
                (*tty->driver->set_termios)(tty, &old_termios);
 
-       if (tty->ldisc.set_termios)
-               (*tty->ldisc.set_termios)(tty, &old_termios);
+       ld = tty_ldisc_ref(tty);
+       if (ld != NULL) {
+               if (ld->set_termios)
+                       (ld->set_termios)(tty, &old_termios);
+               tty_ldisc_deref(ld);
+       }
+       up(&tty->termios_sem);
 }
 
-static int set_termios(struct tty_struct * tty, unsigned long arg, int opt)
+static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
 {
        struct termios tmp_termios;
+       struct tty_ldisc *ld;
        int retval = tty_check_change(tty);
 
        if (retval)
@@ -151,17 +167,22 @@ static int set_termios(struct tty_struct * tty, unsigned long arg, int opt)
        if (opt & TERMIOS_TERMIO) {
                memcpy(&tmp_termios, tty->termios, sizeof(struct termios));
                if (user_termio_to_kernel_termios(&tmp_termios,
-                                                 (struct termio *) arg))
+                                               (struct termio __user *)arg))
                        return -EFAULT;
        } else {
                if (user_termios_to_kernel_termios(&tmp_termios,
-                                                  (struct termios *) arg))
+                                               (struct termios __user *)arg))
                        return -EFAULT;
        }
 
-       if ((opt & TERMIOS_FLUSH) && tty->ldisc.flush_buffer)
-               tty->ldisc.flush_buffer(tty);
-
+       ld = tty_ldisc_ref(tty);
+       
+       if (ld != NULL) {
+               if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
+                       ld->flush_buffer(tty);
+               tty_ldisc_deref(ld);
+       }
+       
        if (opt & TERMIOS_WAIT) {
                tty_wait_until_sent(tty, 0);
                if (signal_pending(current))
@@ -172,7 +193,7 @@ static int set_termios(struct tty_struct * tty, unsigned long arg, int opt)
        return 0;
 }
 
-static int get_termio(struct tty_struct * tty, struct termio * termio)
+static int get_termio(struct tty_struct * tty, struct termio __user * termio)
 {
        if (kernel_termios_to_user_termio(termio, tty->termios))
                return -EFAULT;
@@ -222,15 +243,18 @@ static int get_sgflags(struct tty_struct * tty)
        return flags;
 }
 
-static int get_sgttyb(struct tty_struct * tty, struct sgttyb * sgttyb)
+static int get_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
 {
        struct sgttyb tmp;
 
+       down(&tty->termios_sem);
        tmp.sg_ispeed = 0;
        tmp.sg_ospeed = 0;
        tmp.sg_erase = tty->termios->c_cc[VERASE];
        tmp.sg_kill = tty->termios->c_cc[VKILL];
        tmp.sg_flags = get_sgflags(tty);
+       up(&tty->termios_sem);
+       
        return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
 
@@ -260,7 +284,7 @@ static void set_sgflags(struct termios * termios, int flags)
        }
 }
 
-static int set_sgttyb(struct tty_struct * tty, struct sgttyb * sgttyb)
+static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
 {
        int retval;
        struct sgttyb tmp;
@@ -269,19 +293,23 @@ static int set_sgttyb(struct tty_struct * tty, struct sgttyb * sgttyb)
        retval = tty_check_change(tty);
        if (retval)
                return retval;
-       termios =  *tty->termios;
+       
        if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
                return -EFAULT;
+
+       down(&tty->termios_sem);                
+       termios =  *tty->termios;
        termios.c_cc[VERASE] = tmp.sg_erase;
        termios.c_cc[VKILL] = tmp.sg_kill;
        set_sgflags(&termios, tmp.sg_flags);
+       up(&tty->termios_sem);
        change_termios(tty, &termios);
        return 0;
 }
 #endif
 
 #ifdef TIOCGETC
-static int get_tchars(struct tty_struct * tty, struct tchars * tchars)
+static int get_tchars(struct tty_struct * tty, struct tchars __user * tchars)
 {
        struct tchars tmp;
 
@@ -294,7 +322,7 @@ static int get_tchars(struct tty_struct * tty, struct tchars * tchars)
        return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
 
-static int set_tchars(struct tty_struct * tty, struct tchars * tchars)
+static int set_tchars(struct tty_struct * tty, struct tchars __user * tchars)
 {
        struct tchars tmp;
 
@@ -311,7 +339,7 @@ static int set_tchars(struct tty_struct * tty, struct tchars * tchars)
 #endif
 
 #ifdef TIOCGLTC
-static int get_ltchars(struct tty_struct * tty, struct ltchars * ltchars)
+static int get_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
 {
        struct ltchars tmp;
 
@@ -324,7 +352,7 @@ static int get_ltchars(struct tty_struct * tty, struct ltchars * ltchars)
        return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
 
-static int set_ltchars(struct tty_struct * tty, struct ltchars * ltchars)
+static int set_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
 {
        struct ltchars tmp;
 
@@ -344,7 +372,7 @@ static int set_ltchars(struct tty_struct * tty, struct ltchars * ltchars)
 /*
  * Send a high priority character to the tty.
  */
-void send_prio_char(struct tty_struct *tty, char ch)
+static void send_prio_char(struct tty_struct *tty, char ch)
 {
        int     was_stopped = tty->stopped;
 
@@ -354,7 +382,7 @@ void send_prio_char(struct tty_struct *tty, char ch)
        }
        if (was_stopped)
                start_tty(tty);
-       tty->driver->write(tty, 0, &ch, 1);
+       tty->driver->write(tty, &ch, 1);
        if (was_stopped)
                stop_tty(tty);
 }
@@ -363,7 +391,9 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
                       unsigned int cmd, unsigned long arg)
 {
        struct tty_struct * real_tty;
+       void __user *p = (void __user *)arg;
        int retval;
+       struct tty_ldisc *ld;
 
        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
            tty->driver->subtype == PTY_TYPE_MASTER)
@@ -374,41 +404,41 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
        switch (cmd) {
 #ifdef TIOCGETP
                case TIOCGETP:
-                       return get_sgttyb(real_tty, (struct sgttyb *) arg);
+                       return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
                case TIOCSETP:
                case TIOCSETN:
-                       return set_sgttyb(real_tty, (struct sgttyb *) arg);
+                       return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
 #endif
 #ifdef TIOCGETC
                case TIOCGETC:
-                       return get_tchars(real_tty, (struct tchars *) arg);
+                       return get_tchars(real_tty, p);
                case TIOCSETC:
-                       return set_tchars(real_tty, (struct tchars *) arg);
+                       return set_tchars(real_tty, p);
 #endif
 #ifdef TIOCGLTC
                case TIOCGLTC:
-                       return get_ltchars(real_tty, (struct ltchars *) arg);
+                       return get_ltchars(real_tty, p);
                case TIOCSLTC:
-                       return set_ltchars(real_tty, (struct ltchars *) arg);
+                       return set_ltchars(real_tty, p);
 #endif
                case TCGETS:
-                       if (kernel_termios_to_user_termios((struct termios *)arg, real_tty->termios))
+                       if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
                                return -EFAULT;
                        return 0;
                case TCSETSF:
-                       return set_termios(real_tty, arg,  TERMIOS_FLUSH | TERMIOS_WAIT);
+                       return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
                case TCSETSW:
-                       return set_termios(real_tty, arg, TERMIOS_WAIT);
+                       return set_termios(real_tty, p, TERMIOS_WAIT);
                case TCSETS:
-                       return set_termios(real_tty, arg, 0);
+                       return set_termios(real_tty, p, 0);
                case TCGETA:
-                       return get_termio(real_tty,(struct termio *) arg);
+                       return get_termio(real_tty, p);
                case TCSETAF:
-                       return set_termios(real_tty, arg, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
+                       return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
                case TCSETAW:
-                       return set_termios(real_tty, arg, TERMIOS_WAIT | TERMIOS_TERMIO);
+                       return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
                case TCSETA:
-                       return set_termios(real_tty, arg, TERMIOS_TERMIO);
+                       return set_termios(real_tty, p, TERMIOS_TERMIO);
                case TCXONC:
                        retval = tty_check_change(tty);
                        if (retval)
@@ -442,41 +472,45 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
                        retval = tty_check_change(tty);
                        if (retval)
                                return retval;
+                               
+                       ld = tty_ldisc_ref(tty);
                        switch (arg) {
                        case TCIFLUSH:
-                               if (tty->ldisc.flush_buffer)
-                                       tty->ldisc.flush_buffer(tty);
+                               if (ld->flush_buffer)
+                                       ld->flush_buffer(tty);
                                break;
                        case TCIOFLUSH:
-                               if (tty->ldisc.flush_buffer)
-                                       tty->ldisc.flush_buffer(tty);
+                               if (ld->flush_buffer)
+                                       ld->flush_buffer(tty);
                                /* fall through */
                        case TCOFLUSH:
                                if (tty->driver->flush_buffer)
                                        tty->driver->flush_buffer(tty);
                                break;
                        default:
+                               tty_ldisc_deref(ld);
                                return -EINVAL;
                        }
+                       tty_ldisc_deref(ld);
                        return 0;
                case TIOCOUTQ:
                        return put_user(tty->driver->chars_in_buffer ?
                                        tty->driver->chars_in_buffer(tty) : 0,
-                                       (int *) arg);
+                                       (int __user *) arg);
                case TIOCINQ:
                        retval = tty->read_cnt;
                        if (L_ICANON(tty))
                                retval = inq_canon(tty);
-                       return put_user(retval, (unsigned int *) arg);
+                       return put_user(retval, (unsigned int __user *) arg);
                case TIOCGLCKTRMIOS:
-                       if (kernel_termios_to_user_termios((struct termios *)arg, real_tty->termios_locked))
+                       if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
                                return -EFAULT;
                        return 0;
 
                case TIOCSLCKTRMIOS:
                        if (!capable(CAP_SYS_ADMIN))
                                return -EPERM;
-                       if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios *) arg))
+                       if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios __user *) arg))
                                return -EFAULT;
                        return 0;
 
@@ -487,7 +521,7 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
                        if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
                            tty->driver->subtype != PTY_TYPE_MASTER)
                                return -ENOTTY;
-                       if (get_user(pktmode, (int *) arg))
+                       if (get_user(pktmode, (int __user *) arg))
                                return -EFAULT;
                        if (pktmode) {
                                if (!tty->packet) {
@@ -499,13 +533,15 @@ int n_tty_ioctl(struct tty_struct * tty, struct file * file,
                        return 0;
                }
                case TIOCGSOFTCAR:
-                       return put_user(C_CLOCAL(tty) ? 1 : 0, (int *) arg);
+                       return put_user(C_CLOCAL(tty) ? 1 : 0, (int __user *)arg);
                case TIOCSSOFTCAR:
-                       if (get_user(arg, (unsigned int *) arg))
+                       if (get_user(arg, (unsigned int __user *) arg))
                                return -EFAULT;
+                       down(&tty->termios_sem);
                        tty->termios->c_cflag =
                                ((tty->termios->c_cflag & ~CLOCAL) |
                                 (arg ? CLOCAL : 0));
+                       up(&tty->termios_sem);
                        return 0;
                default:
                        return -ENOIOCTLCMD;