linux/drivers/tty/tty_mutex.c, branch v4.4

tty: Make lock subclasses available for other tty locks

2015-02-02T18:11:27Z

Besides nested legacy_mutex locking which is required on pty pair teardown, other nested pty operations require lock subclassing. Move lock subclass definition to tty interface header, include/linux/tty.h, and document its use. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Remove warning in tty_lock_slave()

2015-01-09T22:17:59Z

Commit 2aff5e2bc62db43e05c814461a08aff0fc2b7fe5 ('tty: Change tty lock order to master->slave') added a warning which is broken and unnecessary now that the tty lock has fixed lock subclasses, added in commit 2febdb632bb96235b94b8fccaf882a78f8f4b2bb ('tty: Preset lock subclass for nested tty locks'). Reported-by: Dan Carpenter Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Preset lock subclass for nested tty locks

2014-11-06T02:50:42Z

Eliminate the requirement of specifying the tty lock nesting at lock time; instead, set the lock subclass for slave ptys at pty install (normal ttys and master ptys use subclass 0). Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Change tty lock order to master->slave

2014-11-06T02:50:42Z

When releasing the master pty, the slave pty also needs to be locked to prevent concurrent tty count changes for the slave pty and to ensure that only one parallel master and slave release observe the final close, and proceed to destruct the pty pair. Conversely, when releasing the slave pty, locking the master pty is not necessary (since the master's state can be inferred by the slave tty count). Introduce tty_lock_slave()/tty_unlock_slave() which acquires/releases the tty lock of the slave pty. Remove tty_lock_pair()/tty_unlock_pair(). Dropping the tty_lock is no longer required to re-establish a stable lock order. Reviewed-by: Alan Cox Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: tty_mutex.c: Fixed coding style warning (using printk)

2012-10-24T18:34:51Z

Here I fixed from printk(KERN_ERR, ... to pr_err(... on tty_mutex.c Signed-off-by: Sangho Yi Signed-off-by: Greg Kroah-Hartman

tty: localise the lock

2012-08-10T19:55:47Z

The termios and other changes mean the other protections needed on the driver tty arrays should be adequate. Turn it all back on. This contains pieces folded in from the fixes made to the original patches | From: Geert Uytterhoeven (fix m68k) | From: Paul Gortmaker (fix cris) | From: Jiri Kosina (lockdep) | From: Eric Dumazet (lockdep) Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

tty: revert incorrectly applied lock patch

2012-07-16T19:58:12Z

I sent GregKH this after the pre-requisites. He dropped the pre-requesites for good reason and unfortunately then applied this patch. Without this reverted you get random kernel memory corruption which will make bisecting anything between it and the properly applied patches a complete sod. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

tty: localise the lock

2012-07-06T21:24:52Z

tty: Revert the tty locking series, it needs more work

2012-06-02T22:21:43Z

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 d29f3ef39be4 ("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: fde86d310886 - tty: add lockdep annotations 8f6576ad476b - tty: fix ldisc lock inversion trace d3ca8b64b97e - pty: Fix lock inversion b1d679afd766 - tty: drop the pty lock during hangup abcefe5fc357 - tty/amiserial: Add missing argument for tty_unlock() fd11b42e3598 - cris: fix missing tty arg in wait_event_interruptible_tty call d29f3ef39be4 - 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

tty: add lockdep annotations

2012-05-31T18:59:41Z

tty_lock_pair() do the right thing to avoid deadlocks, but should instruct LOCKDEP of this to avoid a splat. Signed-off-by: Eric Dumazet Signed-off-by: Linus Torvalds