#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
-#include <linux/smp_lock.h>
#include <asm/io.h>
#include <asm/uaccess.h>
* @tty: terminal
*
* Indicate that a tty should stop transmitting data down the stack.
+ * Takes the termios mutex to protect against parallel throttle/unthrottle
+ * and also to ensure the driver can consistently reference its own
+ * termios data at this point when implementing software flow control.
*/
void tty_throttle(struct tty_struct *tty)
{
+ mutex_lock(&tty->termios_mutex);
/* check TTY_THROTTLED first so it indicates our state */
if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
tty->ops->throttle)
tty->ops->throttle(tty);
+ mutex_unlock(&tty->termios_mutex);
}
EXPORT_SYMBOL(tty_throttle);
* @tty: terminal
*
* Indicate that a tty may continue transmitting data down the stack.
+ * Takes the termios mutex to protect against parallel throttle/unthrottle
+ * and also to ensure the driver can consistently reference its own
+ * termios data at this point when implementing software flow control.
+ *
+ * Drivers should however remember that the stack can issue a throttle,
+ * then change flow control method, then unthrottle.
*/
void tty_unthrottle(struct tty_struct *tty)
{
+ mutex_lock(&tty->termios_mutex);
if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
tty->ops->unthrottle)
tty->ops->unthrottle(tty);
+ mutex_unlock(&tty->termios_mutex);
}
EXPORT_SYMBOL(tty_unthrottle);
termios->c_cflag |= (BOTHER << IBSHIFT);
#else
if (ifound == -1 || ofound == -1) {
- static int warned;
- if (!warned++)
- printk(KERN_WARNING "tty: Unable to return correct "
+ printk_once(KERN_WARNING "tty: Unable to return correct "
"speed data as your architecture needs updating.\n");
}
#endif
static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
- int canon_change;
struct ktermios old_termios;
struct tty_ldisc *ld;
unsigned long flags;
old_termios = *tty->termios;
*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;
- if (canon_change) {
- memset(&tty->read_flags, 0, sizeof tty->read_flags);
- tty->canon_head = tty->read_tail;
- tty->canon_data = 0;
- tty->erasing = 0;
- }
-
- /* This bit should be in the ldisc code */
- 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. */
if (tty->link && tty->link->packet) {
return 0;
}
+static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
+{
+ mutex_lock(&tty->termios_mutex);
+ memcpy(kterm, tty->termios, sizeof(struct ktermios));
+ mutex_unlock(&tty->termios_mutex);
+}
+
+static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
+{
+ mutex_lock(&tty->termios_mutex);
+ memcpy(kterm, tty->termios_locked, sizeof(struct ktermios));
+ mutex_unlock(&tty->termios_mutex);
+}
+
static int get_termio(struct tty_struct *tty, struct termio __user *termio)
{
- if (kernel_termios_to_user_termio(termio, tty->termios))
+ struct ktermios kterm;
+ copy_termios(tty, &kterm);
+ if (kernel_termios_to_user_termio(termio, &kterm))
return -EFAULT;
return 0;
}
#endif
-static unsigned long inq_canon(struct tty_struct *tty)
-{
- int nr, head, tail;
-
- if (!tty->canon_data || !tty->read_buf)
- return 0;
- head = tty->canon_head;
- tail = tty->read_tail;
- nr = (head - tail) & (N_TTY_BUF_SIZE-1);
- /* Skip EOF-chars.. */
- while (head != tail) {
- if (test_bit(tail, tty->read_flags) &&
- tty->read_buf[tail] == __DISABLED_CHAR)
- nr--;
- tail = (tail+1) & (N_TTY_BUF_SIZE-1);
- }
- return nr;
-}
#ifdef TIOCGETP
/*
struct tty_struct *real_tty;
void __user *p = (void __user *)arg;
int ret = 0;
+ struct ktermios kterm;
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
return set_termios(real_tty, p, TERMIOS_OLD);
#ifndef TCGETS2
case TCGETS:
- mutex_lock(&real_tty->termios_mutex);
- if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
+ copy_termios(real_tty, &kterm);
+ if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
ret = -EFAULT;
- mutex_unlock(&real_tty->termios_mutex);
return ret;
#else
case TCGETS:
- mutex_lock(&real_tty->termios_mutex);
- if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios))
+ copy_termios(real_tty, &kterm);
+ if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
ret = -EFAULT;
- mutex_unlock(&real_tty->termios_mutex);
return ret;
case TCGETS2:
- mutex_lock(&real_tty->termios_mutex);
- if (kernel_termios_to_user_termios((struct termios2 __user *)arg, real_tty->termios))
+ copy_termios(real_tty, &kterm);
+ if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
ret = -EFAULT;
- mutex_unlock(&real_tty->termios_mutex);
return ret;
case TCSETSF2:
return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
return set_termios(real_tty, p, TERMIOS_TERMIO);
#ifndef TCGETS2
case TIOCGLCKTRMIOS:
- mutex_lock(&real_tty->termios_mutex);
- if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
+ copy_termios_locked(real_tty, &kterm);
+ if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
ret = -EFAULT;
- mutex_unlock(&real_tty->termios_mutex);
return ret;
case TIOCSLCKTRMIOS:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- mutex_lock(&real_tty->termios_mutex);
- if (user_termios_to_kernel_termios(real_tty->termios_locked,
+ copy_termios_locked(real_tty, &kterm);
+ if (user_termios_to_kernel_termios(&kterm,
(struct termios __user *) arg))
- ret = -EFAULT;
+ return -EFAULT;
+ mutex_lock(&real_tty->termios_mutex);
+ memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
mutex_unlock(&real_tty->termios_mutex);
- return ret;
+ return 0;
#else
case TIOCGLCKTRMIOS:
- mutex_lock(&real_tty->termios_mutex);
- if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked))
+ copy_termios_locked(real_tty, &kterm);
+ if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
ret = -EFAULT;
- mutex_unlock(&real_tty->termios_mutex);
return ret;
case TIOCSLCKTRMIOS:
if (!capable(CAP_SYS_ADMIN))
- ret = -EPERM;
- mutex_lock(&real_tty->termios_mutex);
- if (user_termios_to_kernel_termios_1(real_tty->termios_locked,
+ return -EPERM;
+ copy_termios_locked(real_tty, &kterm);
+ if (user_termios_to_kernel_termios_1(&kterm,
(struct termios __user *) arg))
- ret = -EFAULT;
+ return -EFAULT;
+ mutex_lock(&real_tty->termios_mutex);
+ memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
mutex_unlock(&real_tty->termios_mutex);
return ret;
#endif
#ifdef TCGETX
- case TCGETX:
+ case TCGETX: {
+ struct termiox ktermx;
if (real_tty->termiox == NULL)
return -EINVAL;
mutex_lock(&real_tty->termios_mutex);
- if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox)))
- ret = -EFAULT;
+ memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
mutex_unlock(&real_tty->termios_mutex);
+ if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
+ ret = -EFAULT;
return ret;
+ }
case TCSETX:
return set_termiox(real_tty, p, 0);
case TCSETXW:
return set_termiox(real_tty, p, TERMIOS_FLUSH);
#endif
case TIOCGSOFTCAR:
- mutex_lock(&real_tty->termios_mutex);
- ret = put_user(C_CLOCAL(real_tty) ? 1 : 0,
+ copy_termios(real_tty, &kterm);
+ ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
(int __user *)arg);
- mutex_unlock(&real_tty->termios_mutex);
return ret;
case TIOCSSOFTCAR:
if (get_user(arg, (unsigned int __user *) arg))
if (retval)
return retval;
- ld = tty_ldisc_ref(tty);
+ ld = tty_ldisc_ref_wait(tty);
switch (arg) {
case TCIFLUSH:
if (ld && ld->ops->flush_buffer)
}
EXPORT_SYMBOL_GPL(tty_perform_flush);
-int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
unsigned long flags;
return 0;
case TCFLSH:
return tty_perform_flush(tty, arg);
- case TIOCOUTQ:
- return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
- case TIOCINQ:
- retval = tty->read_cnt;
- if (L_ICANON(tty))
- retval = inq_canon(tty);
- return put_user(retval, (unsigned int __user *) arg);
case TIOCPKT:
{
int pktmode;
return tty_mode_ioctl(tty, file, cmd, arg);
}
}
-EXPORT_SYMBOL(n_tty_ioctl);
+EXPORT_SYMBOL(n_tty_ioctl_helper);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff