linux-toradex.git/drivers/tty/tty_mutex.c, branch v4.4.93 Linux kernel for Apalis and Colibri modules tty: Drop krefs for interrupted tty lock 2017-06-14T11:16:26+00:00 Peter Hurley peter@hurleysoftware.com 2016-02-05T18:49:36+00:00 cc04a1433843ff8518f3bf6733e99abb05458b82 commit e9036d0662360cd4c79578565ce422ed5872f301 upstream. When the tty lock is interrupted on attempted re-open, 2 tty krefs are still held. Drop extra kref before returning failure from tty_lock_interruptible(), and drop lookup kref before returning failure from tty_open(). Fixes: 0bfd464d3fdd ("tty: Wait interruptibly for tty lock on reopen") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e9036d0662360cd4c79578565ce422ed5872f301 upstream.

When the tty lock is interrupted on attempted re-open, 2 tty krefs
are still held. Drop extra kref before returning failure from
tty_lock_interruptible(), and drop lookup kref before returning
failure from tty_open().

Fixes: 0bfd464d3fdd ("tty: Wait interruptibly for tty lock on reopen")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Wait interruptibly for tty lock on reopen 2016-02-17T20:31:02+00:00 Peter Hurley peter@hurleysoftware.com 2016-01-10T05:13:44+00:00 c35f1234931e2cae81726440ad4df8ef1f313219 commit 0bfd464d3fdd5bb322f9cace4cc47f1796545cf7 upstream. Allow a signal to interrupt the wait for a tty reopen; eg., if the tty has starting final close and is waiting for the device to drain. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0bfd464d3fdd5bb322f9cace4cc47f1796545cf7 upstream.

Allow a signal to interrupt the wait for a tty reopen; eg., if
the tty has starting final close and is waiting for the device to
drain.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Make lock subclasses available for other tty locks 2015-02-02T18:11:27+00:00 Peter Hurley peter@hurleysoftware.com 2015-01-17T20:42:04+00:00 3abf87cd3e70009ed70a7f28c2914888a7e27332 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 <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Remove warning in tty_lock_slave() 2015-01-09T22:17:59+00:00 Peter Hurley peter@hurleysoftware.com 2014-12-30T12:11:11+00:00 eef15e2a54fad4c2ce3f0a81485dc591ce678f4f 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 <dan.carpenter@oracle.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <dan.carpenter@oracle.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Preset lock subclass for nested tty locks 2014-11-06T02:50:42+00:00 Peter Hurley peter@hurleysoftware.com 2014-11-05T17:13:02+00:00 2febdb632bb96235b94b8fccaf882a78f8f4b2bb 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 <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Change tty lock order to master->slave 2014-11-06T02:50:42+00:00 Peter Hurley peter@hurleysoftware.com 2014-11-05T17:13:01+00:00 2aff5e2bc62db43e05c814461a08aff0fc2b7fe5 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 <alan@linux.intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <alan@linux.intel.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: tty_mutex.c: Fixed coding style warning (using printk) 2012-10-24T18:34:51+00:00 Sangho Yi antiroot@gmail.com 2012-10-17T15:15:13+00:00 7a0c4edae99da6ab3d402deb0d88410251c6ac63 Here I fixed from printk(KERN_ERR, ... to pr_err(... on tty_mutex.c Signed-off-by: Sangho Yi <antiroot@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Here I fixed from printk(KERN_ERR, ... to pr_err(... on tty_mutex.c

Signed-off-by: Sangho Yi <antiroot@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: localise the lock 2012-08-10T19:55:47+00:00 Alan Cox alan@linux.intel.com 2012-08-08T15:30:13+00:00 89c8d91e31f267703e365593f6bfebb9f6d2ad01 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 <geert@linux-m68k.org> (fix m68k) | From: Paul Gortmaker <paul.gortmaker@windriver.com> (fix cris) | From: Jiri Kosina <jkosina@suze.cz> (lockdep) | From: Eric Dumazet <eric.dumazet@gmail.com> (lockdep) Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <geert@linux-m68k.org>	(fix m68k)
| From: Paul Gortmaker <paul.gortmaker@windriver.com>	(fix cris)
| From: Jiri Kosina <jkosina@suze.cz>			(lockdep)
| From: Eric Dumazet <eric.dumazet@gmail.com>		(lockdep)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: revert incorrectly applied lock patch 2012-07-16T19:58:12+00:00 Alan Cox alan@linux.intel.com 2012-07-14T14:31:27+00:00 6d31a88cb2e01d46c0cb74aa5da529e1f92ae3db 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 <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: localise the lock 2012-07-06T21:24:52+00:00 Alan Cox alan@linux.intel.com 2012-06-29T13:48:36+00:00 f5e3bcc504c3c35cc6e06a9ee42efed7c274066b 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 <geert@linux-m68k.org> (fix m68k) | From: Paul Gortmaker <paul.gortmaker@windriver.com> (fix cris) | From: Jiri Kosina <jkosina@suze.cz> (lockdep) | From: Eric Dumazet <eric.dumazet@gmail.com> (lockdep) Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <geert@linux-m68k.org>	(fix m68k)
| From: Paul Gortmaker <paul.gortmaker@windriver.com>	(fix cris)
| From: Jiri Kosina <jkosina@suze.cz>			(lockdep)
| From: Eric Dumazet <eric.dumazet@gmail.com>		(lockdep)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>