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author | Alan Cox <alan@redhat.com> | 2008-10-13 10:38:46 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-13 09:51:41 -0700 |
commit | 8f520021837d45c47d0ab57e7271f8d88bf7f3a4 (patch) | |
tree | 4435f3141163480c23f7274c502d58e3cd9cb963 /drivers/char/tty_ioctl.c | |
parent | 1d65b4a088de407e99714fdc27862449db04fb5c (diff) | |
download | linux-3.10-8f520021837d45c47d0ab57e7271f8d88bf7f3a4.tar.gz linux-3.10-8f520021837d45c47d0ab57e7271f8d88bf7f3a4.tar.bz2 linux-3.10-8f520021837d45c47d0ab57e7271f8d88bf7f3a4.zip |
tty: Termios locking - sort out real_tty confusions and lock reads
This moves us towards sanity and should mean our termios locking is now
complete and comprehensive.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/tty_ioctl.c')
-rw-r--r-- | drivers/char/tty_ioctl.c | 58 |
1 files changed, 38 insertions, 20 deletions
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index 93bfa1d6cc9..30670851e51 100644 --- a/drivers/char/tty_ioctl.c +++ b/drivers/char/tty_ioctl.c @@ -893,6 +893,7 @@ 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; if (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER) @@ -928,18 +929,24 @@ 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)) - return -EFAULT; - return 0; + 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)) - return -EFAULT; - return 0; + 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)) - return -EFAULT; - return 0; + ret = -EFAULT; + mutex_unlock(&real_tty->termios_mutex); + return ret; case TCSETSF2: return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT); case TCSETSW2: @@ -957,36 +964,46 @@ 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)) - return -EFAULT; - return 0; + 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, (struct termios __user *) arg)) - return -EFAULT; - return 0; + ret = -EFAULT; + mutex_unlock(&real_tty->termios_mutex); + return ret; #else case TIOCGLCKTRMIOS: + mutex_lock(&real_tty->termios_mutex); if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked)) - return -EFAULT; - return 0; + ret = -EFAULT; + mutex_unlock(&real_tty->termios_mutex); + return ret; case TIOCSLCKTRMIOS: if (!capable(CAP_SYS_ADMIN)) - return -EPERM; + ret = -EPERM; + mutex_lock(&real_tty->termios_mutex); if (user_termios_to_kernel_termios_1(real_tty->termios_locked, (struct termios __user *) arg)) - return -EFAULT; - return 0; + ret = -EFAULT; + mutex_unlock(&real_tty->termios_mutex); + return ret; #endif #ifdef TCGETX case TCGETX: if (real_tty->termiox == NULL) return -EINVAL; + mutex_lock(&real_tty->termios_mutex); if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox))) - return -EFAULT; - return 0; + ret = -EFAULT; + mutex_unlock(&real_tty->termios_mutex); + return ret; case TCSETX: return set_termiox(real_tty, p, 0); case TCSETXW: @@ -995,10 +1012,11 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, return set_termiox(real_tty, p, TERMIOS_FLUSH); #endif case TIOCGSOFTCAR: - /* FIXME: for correctness we may need to take the termios - lock here - review */ - return put_user(C_CLOCAL(real_tty) ? 1 : 0, + mutex_lock(&real_tty->termios_mutex); + ret = put_user(C_CLOCAL(real_tty) ? 1 : 0, (int __user *)arg); + mutex_unlock(&real_tty->termios_mutex); + return ret; case TIOCSSOFTCAR: if (get_user(arg, (unsigned int __user *) arg)) return -EFAULT; |