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authorAlan Cox <alan@linux.intel.com>2009-06-11 14:03:13 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-11 08:51:06 -0700
commit26a2e20f4a966bebc312836aeb4423fbfd4e33e2 (patch)
tree69c2d9fc4eba1e62a66892173ea0a4c599768f12 /drivers
parent0b91421857414f525690ee452c0b0acb6ab1dba3 (diff)
tty: Untangle termios and mm mutex dependencies
Although this doesn't cause any problems it could potentially do so for future mmap using devices. No real work is needed to sort it out so untangle it before it causes problems Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/tty_ioctl.c75
1 files changed, 46 insertions, 29 deletions
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index 2401dbcbee9c..8116bb1c8f80 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -626,9 +626,25 @@ static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
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;
}
@@ -930,6 +946,8 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
struct tty_struct *real_tty;
void __user *p = (void __user *)arg;
int ret = 0;
+ struct ktermios kterm;
+ struct termiox ktermx;
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
@@ -965,23 +983,20 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
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);
@@ -1000,34 +1015,36 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
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
@@ -1036,9 +1053,10 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
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);
@@ -1048,10 +1066,9 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
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))