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tty: Revert the tty locking series, it needs more work
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This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d3 - tty: add lockdep annotations
  8f6576a - tty: fix ldisc lock inversion trace
  d3ca8b6 - pty: Fix lock inversion
  b1d679a - tty: drop the pty lock during hangup
  abcefe5 - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42 - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.

Signed-off-by: Linus Torvalds <[email protected]>
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@torvalds
torvalds committed Jun 2, 2012
1 parent 233e562 commit f309532
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Showing 14 changed files with 119 additions and 191 deletions.
14 changes: 7 additions & 7 deletions drivers/tty/amiserial.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1033,7 +1033,7 @@ static int get_serial_info(struct tty_struct *tty, struct serial_state *state,
if (!retinfo)
return -EFAULT;
memset(&tmp, 0, sizeof(tmp));
tty_lock(tty);
tty_lock();
tmp.line = tty->index;
tmp.port = state->port;
tmp.flags = state->tport.flags;
Expand All @@ -1042,7 +1042,7 @@ static int get_serial_info(struct tty_struct *tty, struct serial_state *state,
tmp.close_delay = state->tport.close_delay;
tmp.closing_wait = state->tport.closing_wait;
tmp.custom_divisor = state->custom_divisor;
tty_unlock(tty);
tty_unlock();
if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
return -EFAULT;
return 0;
Expand All @@ -1059,12 +1059,12 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
return -EFAULT;

tty_lock(tty);
tty_lock();
change_spd = ((new_serial.flags ^ port->flags) & ASYNC_SPD_MASK) ||
new_serial.custom_divisor != state->custom_divisor;
if (new_serial.irq || new_serial.port != state->port ||
new_serial.xmit_fifo_size != state->xmit_fifo_size) {
tty_unlock(tty);
tty_unlock();
return -EINVAL;
}

Expand All @@ -1074,7 +1074,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
(new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
((new_serial.flags & ~ASYNC_USR_MASK) !=
(port->flags & ~ASYNC_USR_MASK))) {
tty_unlock(tty);
tty_unlock();
return -EPERM;
}
port->flags = ((port->flags & ~ASYNC_USR_MASK) |
Expand All @@ -1084,7 +1084,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
}

if (new_serial.baud_base < 9600) {
tty_unlock(tty);
tty_unlock();
return -EINVAL;
}

Expand Down Expand Up @@ -1116,7 +1116,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state,
}
} else
retval = startup(tty, state);
tty_unlock(tty);
tty_unlock();
return retval;
}

Expand Down
2 changes: 1 addition & 1 deletion drivers/tty/cyclades.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1599,7 +1599,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp)
* If the port is the middle of closing, bail out now
*/
if (tty_hung_up_p(filp) || (info->port.flags & ASYNC_CLOSING)) {
wait_event_interruptible_tty(tty, info->port.close_wait,
wait_event_interruptible_tty(info->port.close_wait,
!(info->port.flags & ASYNC_CLOSING));
return (info->port.flags & ASYNC_HUP_NOTIFY) ? -EAGAIN: -ERESTARTSYS;
}
Expand Down
11 changes: 5 additions & 6 deletions drivers/tty/n_r3964.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1065,8 +1065,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,

TRACE_L("read()");

/* FIXME: should use a private lock */
tty_lock(tty);
tty_lock();

pClient = findClient(pInfo, task_pid(current));
if (pClient) {
Expand All @@ -1078,7 +1077,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
goto unlock;
}
/* block until there is a message: */
wait_event_interruptible_tty(tty, pInfo->read_wait,
wait_event_interruptible_tty(pInfo->read_wait,
(pMsg = remove_msg(pInfo, pClient)));
}

Expand Down Expand Up @@ -1108,7 +1107,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
}
ret = -EPERM;
unlock:
tty_unlock(tty);
tty_unlock();
return ret;
}

Expand Down Expand Up @@ -1157,7 +1156,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
pHeader->locks = 0;
pHeader->owner = NULL;

tty_lock(tty);
tty_lock();

pClient = findClient(pInfo, task_pid(current));
if (pClient) {
Expand All @@ -1176,7 +1175,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
add_tx_queue(pInfo, pHeader);
trigger_transmit(pInfo);

tty_unlock(tty);
tty_unlock();

return 0;
}
Expand Down
25 changes: 11 additions & 14 deletions drivers/tty/pty.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,6 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
wake_up_interruptible(&tty->read_wait);
wake_up_interruptible(&tty->write_wait);
tty->packet = 0;
/* Review - krefs on tty_link ?? */
if (!tty->link)
return;
tty->link->packet = 0;
Expand All @@ -63,9 +62,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
mutex_unlock(&devpts_mutex);
}
#endif
tty_unlock(tty);
tty_unlock();
tty_vhangup(tty->link);
tty_lock(tty);
tty_lock();
}
}

Expand Down Expand Up @@ -623,27 +622,26 @@ static int ptmx_open(struct inode *inode, struct file *filp)
return retval;

/* find a device that is not in use. */
mutex_lock(&devpts_mutex);
tty_lock();
index = devpts_new_index(inode);
tty_unlock();
if (index < 0) {
retval = index;
goto err_file;
}

mutex_unlock(&devpts_mutex);

mutex_lock(&tty_mutex);
mutex_lock(&devpts_mutex);
tty = tty_init_dev(ptm_driver, index);
mutex_unlock(&devpts_mutex);
tty_lock();
mutex_unlock(&tty_mutex);

if (IS_ERR(tty)) {
retval = PTR_ERR(tty);
goto out;
}

/* The tty returned here is locked so we can safely
drop the mutex */
mutex_unlock(&tty_mutex);

set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */

tty_add_file(tty, filp);
Expand All @@ -656,17 +654,16 @@ static int ptmx_open(struct inode *inode, struct file *filp)
if (retval)
goto err_release;

tty_unlock(tty);
tty_unlock();
return 0;
err_release:
tty_unlock(tty);
tty_unlock();
tty_release(inode, filp);
return retval;
out:
mutex_unlock(&tty_mutex);
devpts_kill_index(inode, index);
tty_unlock();
err_file:
mutex_unlock(&devpts_mutex);
tty_free_file(filp);
return retval;
}
Expand Down
8 changes: 4 additions & 4 deletions drivers/tty/serial/crisv10.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3976,7 +3976,7 @@ block_til_ready(struct tty_struct *tty, struct file * filp,
*/
if (tty_hung_up_p(filp) ||
(info->flags & ASYNC_CLOSING)) {
wait_event_interruptible_tty(tty, info->close_wait,
wait_event_interruptible_tty(info->close_wait,
!(info->flags & ASYNC_CLOSING));
#ifdef SERIAL_DO_RESTART
if (info->flags & ASYNC_HUP_NOTIFY)
Expand Down Expand Up @@ -4052,9 +4052,9 @@ block_til_ready(struct tty_struct *tty, struct file * filp,
printk("block_til_ready blocking: ttyS%d, count = %d\n",
info->line, info->count);
#endif
tty_unlock(tty);
tty_unlock();
schedule();
tty_lock(tty);
tty_lock();
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&info->open_wait, &wait);
Expand Down Expand Up @@ -4115,7 +4115,7 @@ rs_open(struct tty_struct *tty, struct file * filp)
*/
if (tty_hung_up_p(filp) ||
(info->flags & ASYNC_CLOSING)) {
wait_event_interruptible_tty(tty, info->close_wait,
wait_event_interruptible_tty(info->close_wait,
!(info->flags & ASYNC_CLOSING));
#ifdef SERIAL_DO_RESTART
return ((info->flags & ASYNC_HUP_NOTIFY) ?
Expand Down
4 changes: 2 additions & 2 deletions drivers/tty/synclink.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3338,9 +3338,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
printk("%s(%d):block_til_ready blocking on %s count=%d\n",
__FILE__,__LINE__, tty->driver->name, port->count );

tty_unlock(tty);
tty_unlock();
schedule();
tty_lock(tty);
tty_lock();
}

set_current_state(TASK_RUNNING);
Expand Down
4 changes: 2 additions & 2 deletions drivers/tty/synclink_gt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3336,9 +3336,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
}

DBGINFO(("%s block_til_ready wait\n", tty->driver->name));
tty_unlock(tty);
tty_unlock();
schedule();
tty_lock(tty);
tty_lock();
}

set_current_state(TASK_RUNNING);
Expand Down
4 changes: 2 additions & 2 deletions drivers/tty/synclinkmp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3357,9 +3357,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
printk("%s(%d):%s block_til_ready() count=%d\n",
__FILE__,__LINE__, tty->driver->name, port->count );

tty_unlock(tty);
tty_unlock();
schedule();
tty_lock(tty);
tty_lock();
}

set_current_state(TASK_RUNNING);
Expand Down
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