linux.git/drivers/tty/vt/vt.c, branch v3.15

vt: detect and ignore OSC codes.

2014-03-01T00:25:47+00:00

These can be used to send commands consisting of an arbitrary string to the
terminal, most often used to set a terminal's window title or to redefine
the colour palette.  Our console doesn't use OSC, unlike everything else,
which can lead to junk being displayed if a process sends such a code
unconditionally.

The rules for termination follow established practice rather than Ecma-48.
Ecma-48 requires the string to use only byte values 0x08..0x0D and
0x20..0x7E, terminated with either ESC \ or 0x9C.  This would disallow using
8-bit characters, which are reasonable for example in window titles.
A widespread idiom is to terminate with 0x07.  The behaviour for other
control characters differs between terminal emulators, I followed libvte and
xterm:
* 0x07 and ESC anything terminate
* nothing else terminates, all 8-bit values including 0x9C are considered a
  part of the string

Signed-off-by: Adam Borowski 
Signed-off-by: Greg Kroah-Hartman

vt: drop an useless enum and assignment.

2014-03-01T00:25:47+00:00

Signed-off-by: Adam Borowski 
Signed-off-by: Greg Kroah-Hartman

vt: Fix secure clear screen

2014-02-13T19:12:00+00:00

\E[3J console code (secure clear screen) needs to update_screen(vc)
in order to write-through blanks into off-screen video memory.

This has been removed accidentally in 3.6 by:

commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c
Author: Jean-François Moine 
Date:   Thu Sep 6 19:24:13 2012 +0200

    tty vt: Fix line garbage in virtual console on command line edition

Signed-off-by: Petr Písař 
Cc: stable  # 3.6
Signed-off-by: Greg Kroah-Hartman

vt: properly ignore xterm-256 colour codes

2013-09-26T22:58:27+00:00

This is not a bug on our side, but a misdesign in ITU T.416, yet with
all popular terminals supporting these codes, people consider this to
be a bug in Linux.  By breaking the design principles behind SGR codes
(gracefully ignoring unsupported ones should not require knowing about
them), 256 colour ones tend to turn blinking on before invoking an
arbitrary unrelated command.

This commit doesn't add such support, merely skips such codes without
ill effects.

Signed-off-by: Adam Borowski 
Signed-off-by: Greg Kroah-Hartman

vt: break a couple of obsolete SCOish codes.

2013-09-26T22:58:26+00:00

No modern terminal supports them, and SGR 38 conflicts with detecting
xterm-256 colours.  This also makes SGR 39 consistent with other popular
terminals.  Neither are used by ncurses' terminfo.

Signed-off-by: Adam Borowski 
Signed-off-by: Greg Kroah-Hartman

vt: make the default color configurable

2013-08-05T07:06:46+00:00

The virtual console has (undocumented) module parameters to set the
colors for italic and underlined text, but the default text color was
hardcoded for some reason.  This made it impossible to change the color
for startup messages, or to set the default for new virtual consoles.
Add a module parameter for that, and document the entire bunch.

Any hacker who thinks that a command prompt on a "black screen with
white font" is not supicious enough can now use the kernel parameter
vt.color=10 to get a nice, evil green.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Greg Kroah-Hartman

tty: Convert termios_mutex to termios_rwsem

2013-07-23T23:43:01+00:00

termios is commonly accessed unsafely (especially by N_TTY)
because the existing mutex forces exclusive access.
Convert existing usage.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

Merge 3.10-rc3 into tty-next

2013-05-27T01:57:53+00:00

We want these fixes.

Signed-off-by: Greg Kroah-Hartman

TTY:vt: convert remain take_over_console's users to do_take_over_console

2013-05-21T05:29:27+00:00

Impact:
1:convert all remain take_over_console to do_take_over_console
2:update take_over_console to do_take_over_console in comment

Commit dc9641895abb ("vt: delete unneeded functions
register_con_driver|take_over_console") delete take_over_console,
but forget to convert remain take_over_console's users to new API
do_take_over_console, this patch fix it.

Reported-by: Stephen Rothwell 
Signed-off-by: Wang YanQing 
Signed-off-by: Greg Kroah-Hartman

vt: delete unneeded function unregister_con_driver

2013-05-20T19:27:59+00:00

Now there is no place use unregister_con_driver,
and we can achieve unregister_con_driver's function
with unregister_con_driver easily, so just delete it
to reduce code size and duplication.

Signed-off-by: Wang YanQing 
Signed-off-by: Greg Kroah-Hartman