diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2013-06-15 09:14:23 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-23 16:43:01 -0700 |
| commit | 6a1c0680cf3ba94356ecd58833e1540c93472a57 (patch) | |
| tree | d370b0888214bb59049181ac98c567d153263f48 /drivers/tty/tty_io.c | |
| parent | a2f73be8ee36e48f11f89ab705beb3c587a2f320 (diff) | |
tty: Convert termios_mutex to termios_rwsem
termios is commonly accessed unsafely (especially by N_TTY)
because the existing mutex forces exclusive access.
Convert existing usage.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 0fa5db4c7a7a..639e24ade9bf 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -604,7 +604,7 @@ static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) * redirect lock for undoing redirection * file list lock for manipulating list of ttys * tty_ldiscs_lock from called functions - * termios_mutex resetting termios data + * termios_rwsem resetting termios data * tasklist_lock to walk task list for hangup event * ->siglock to protect ->signal/->sighand */ @@ -2230,7 +2230,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p) * * Copies the kernel idea of the window size into the user buffer. * - * Locking: tty->termios_mutex is taken to ensure the winsize data + * Locking: tty->termios_rwsem is taken to ensure the winsize data * is consistent. */ @@ -2238,9 +2238,9 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) { int err; - mutex_lock(&tty->termios_mutex); + down_read(&tty->termios_rwsem); err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); - mutex_unlock(&tty->termios_mutex); + up_read(&tty->termios_rwsem); return err ? -EFAULT: 0; } @@ -2261,7 +2261,7 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws) unsigned long flags; /* Lock the tty */ - mutex_lock(&tty->termios_mutex); + down_write(&tty->termios_rwsem); if (!memcmp(ws, &tty->winsize, sizeof(*ws))) goto done; /* Get the PID values and reference them so we can @@ -2276,7 +2276,7 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws) tty->winsize = *ws; done: - mutex_unlock(&tty->termios_mutex); + up_write(&tty->termios_rwsem); return 0; } EXPORT_SYMBOL(tty_do_resize); @@ -3015,7 +3015,7 @@ void initialize_tty_struct(struct tty_struct *tty, tty->session = NULL; tty->pgrp = NULL; mutex_init(&tty->legacy_mutex); - mutex_init(&tty->termios_mutex); + init_rwsem(&tty->termios_rwsem); init_ldsem(&tty->ldisc_sem); init_waitqueue_head(&tty->write_wait); init_waitqueue_head(&tty->read_wait); |