diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2013-06-15 15:14:31 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-24 01:43:02 +0200 |
| commit | d8c1f929aa8164cd8eaa830068d2fa3159c0764a (patch) | |
| tree | 1371cfe90fffdcb7115b39c77e0f729c109efc69 /drivers/tty/tty_ioctl.c | |
| parent | n_tty: Separate buffer indices to prevent cache-line sharing (diff) | |
| download | linux-d8c1f929aa8164cd8eaa830068d2fa3159c0764a.tar.xz linux-d8c1f929aa8164cd8eaa830068d2fa3159c0764a.zip | |
tty: Only guarantee termios read safety for throttle/unthrottle
No tty driver modifies termios during throttle() or unthrottle().
Therefore, only read safety is required.
However, tty_throttle_safe and tty_unthrottle_safe must still be
mutually exclusive; introduce throttle_mutex for that purpose.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_ioctl.c')
| -rw-r--r-- | drivers/tty/tty_ioctl.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 9ce20df8a2c8..03ba081c5772 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -151,7 +151,7 @@ int tty_throttle_safe(struct tty_struct *tty) { int ret = 0; - down_write(&tty->termios_rwsem); + mutex_lock(&tty->throttle_mutex); if (!test_bit(TTY_THROTTLED, &tty->flags)) { if (tty->flow_change != TTY_THROTTLE_SAFE) ret = 1; @@ -161,7 +161,7 @@ int tty_throttle_safe(struct tty_struct *tty) tty->ops->throttle(tty); } } - up_write(&tty->termios_rwsem); + mutex_unlock(&tty->throttle_mutex); return ret; } @@ -182,7 +182,7 @@ int tty_unthrottle_safe(struct tty_struct *tty) { int ret = 0; - down_write(&tty->termios_rwsem); + mutex_lock(&tty->throttle_mutex); if (test_bit(TTY_THROTTLED, &tty->flags)) { if (tty->flow_change != TTY_UNTHROTTLE_SAFE) ret = 1; @@ -192,7 +192,7 @@ int tty_unthrottle_safe(struct tty_struct *tty) tty->ops->unthrottle(tty); } } - up_write(&tty->termios_rwsem); + mutex_unlock(&tty->throttle_mutex); return ret; } |