linux.git/drivers/char/tty_ioctl.c, branch master

TTY: create drivers/tty and move the tty core files there

2010-11-05T15:10:33+00:00

The tty code should be in its own subdirectory and not in the char
driver with all of the cruft that is currently there.

Based on work done by Arnd Bergmann 

Acked-by: Arnd Bergmann 
Cc: Jiri Slaby 
Cc: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: Add EXTPROC support for LINEMODE

2010-08-10T20:47:39+00:00

This patch is against the 2.6.34 source.

Paraphrased from the 1989 BSD patch by David Borman @ cray.com:

     These are the changes needed for the kernel to support
     LINEMODE in the server.

     There is a new bit in the termios local flag word, EXTPROC.
     When this bit is set, several aspects of the terminal driver
     are disabled.  Input line editing, character echo, and mapping
     of signals are all disabled.  This allows the telnetd to turn
     off these functions when in linemode, but still keep track of
     what state the user wants the terminal to be in.

     New ioctl:
         TIOCSIG         Generate a signal to processes in the
                         current process group of the pty.

     There is a new mode for packet driver, the TIOCPKT_IOCTL bit.
     When packet mode is turned on in the pty, and the EXTPROC bit
     is set, then whenever the state of the pty is changed, the
     next read on the master side of the pty will have the TIOCPKT_IOCTL
     bit set.  This allows the process on the server side of the pty
     to know when the state of the terminal has changed; it can then
     issue the appropriate ioctl to retrieve the new state.

Since the original BSD patches accompanied the source code for telnet
I've left that reference here, but obviously the feature is useful for
any remote terminal protocol, including ssh.

The corresponding feature has existed in the BSD tty driver since 1989.
For historical reference, a good copy of the relevant files can be found
here:

http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741

Signed-off-by: Howard Chu 
Cc: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tree-wide: fix a very frequent spelling mistake

2009-11-09T08:40:54+00:00

something-bility is spelled as something-blity
so a grep for 'blit' would find these lines

this is so trivial that I didn't split it by subsystem / copy
additional maintainers - all changes are to comments
The only purpose is to get fewer false positives when grepping
around the kernel sources.

Signed-off-by: Dirk Hohndel 
Signed-off-by: Jiri Kosina

tty: vt: use printk_once

2009-09-19T20:13:35+00:00

Signed-off-by: Marcin Slusarz 
Signed-off-by: Greg Kroah-Hartman

headers: smp_lock.h redux

2009-07-12T19:22:34+00:00

* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

tty: fix unused warning when TCGETX is not defined

2009-06-16T19:01:16+00:00

If TCGETX is not defined, we end up with this warning:
drivers/char/tty_ioctl.c: In function ‘tty_mode_ioctl’:
drivers/char/tty_ioctl.c:950: warning: unused variable ‘ktermx’

Since the variable is only used in one case statement, push it down to
the local case scope.

Signed-off-by: Mike Frysinger 
Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

tty: Untangle termios and mm mutex dependencies

2009-06-11T15:51:06+00:00

Although this doesn't cause any problems it could potentially do so for
future mmap using devices. No real work is needed to sort it out so untangle
it before it causes problems

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

tty: throttling race fix

2009-06-11T15:50:59+00:00

The tty throttling code can race due to the lock drops. It takes very high
loads but this has been observed and verified by Rob Duncan.

The basic problem is that on an SMP box we can go

	CPU #1				CPU #2
	need to throttle ?
	suppose we should		buffer space cleared
					are we throttled
					yes ? - unthrottle
	call throttle method

This changeet take the termios lock to protect against this. The termios
lock isn't the initial obvious candidate but many implementations of throttle
methods already need to poke around their own termios structures (and nobody
really locks them against a racing change of flow control).

This does mean that anyone who is setting tty->low_latency = 1 and then
calling tty_flip_buffer_push from their unthrottle method is going to end up
collapsing in a pile of locks. However we've removed all the known bogus
users of low_latency = 1 and such use isn't safe anyway for other reasons so
catching it would be an improvement.

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

tty: Fix race in the flush for some ldiscs

2009-01-15T20:48:35+00:00

If you issue an ioctl to flush a tty as the line discipline is changing or
otherwise unplugged you can get a crash. The bug is very old but the rest
of the BKL lock dropping and some very "good" luck on Ingo's part caught
an example.

Use the correct ldisc_ref form so that we wait for the ldisc change to
complete and then flush

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

tty: some ICANON magic is in the wrong places

2008-10-13T16:51:44+00:00

Move the set up on ldisc change into the ldisc
Move the INQ/OUTQ cases into the driver not in shared ioctl code where it
gives bogus answers for other ldisc values

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds