linux-stable.git/drivers/tty/vt/vt.c, branch linux-3.7.y

tty vt: fix character insertion overflow

2013-02-27T17:21:07+00:00

commit a883b70d8e0a88278c0a1f80753b4dc99962b541 upstream.

Commit 81732c3b2fed ("tty vt: Fix line garbage in virtual console on
command line edition") broke insert_char() in multiple ways.  Then
commit b1a925f44a3a ("tty vt: Fix a regression in command line edition")
partially fixed it.  However, the buffer being moved is still too large
and overflowing beyond the end of the current line, corrupting existing
characters on the next line.

Example test case:

echo -e "abc\nde\x1b[A\x1b[4h \x1b[4l\x1b[B"

Expected result:

ab c
de

Current result:

ab c
 e

Needless to say that this is very annoying when inserting words in the
middle of paragraphs with certain text editors.

Signed-off-by: Nicolas Pitre 
Acked-by: Jean-François Moine 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

tty vt: Fix a regression in command line edition

2012-11-22T00:45:32+00:00

The commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c
("Fix line garbage in virtual console on command line edition")
made a regression with some machines: some characters were not erased
after line edition.

This patch adjusts the number of moved characters and the size of the
region to be updated.

Signed-off-by: Jean-François Moine 
Tested-by: Krzysztof Mazur 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

2012-10-13T02:16:58+00:00

Pull KGDB/KDB fixes and cleanups from Jason Wessel:
 "Cleanups
   - Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
   - Add module event hooks for simplified debugging with gdb
 Fixes
   - Fix kdb to stop paging with 'q' on bta and dmesg
   - Fix for data that scrolls off the vga console due to line wrapping
     when using the kdb pager
 New
   - The debug core registers for kernel module events which allows a
     kernel aware gdb to automatically load symbols and break on entry
     to a kernel module
   - Allow kgdboc=kdb to setup kdb on the vga console"

* tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  tty/console: fix warnings in drivers/tty/serial/kgdboc.c
  kdb,vt_console: Fix missed data due to pager overruns
  kdb: Fix dmesg/bta scroll to quit with 'q'
  kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell
  kgdb,x86: fix warning about unused variable
  mips,kgdb: fix recursive page fault with CONFIG_KPROBES
  kgdb: Add module event hooks

kdb,vt_console: Fix missed data due to pager overruns

2012-10-12T11:37:35+00:00

It is possible to miss data when using the kdb pager.  The kdb pager
does not pay attention to the maximum column constraint of the screen
or serial terminal.  This result is not incrementing the shown lines
correctly and the pager will print more lines that fit on the screen.
Obviously that is less than useful when using a VGA console where you
cannot scroll back.

The pager will now look at the kdb_buffer string to see how many
characters are printed.  It might not be perfect considering you can
output ASCII that might move the cursor position, but it is a
substantially better approximation for viewing dmesg and trace logs.

This also means that the vt screen needs to set the kdb COLUMNS
variable.

Cc: 
Signed-off-by: Jason Wessel

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

2012-09-10T23:35:46+00:00

On some machines using a specific hardware for console screen output,
the update of the pixel frame buffer does not work correctly when
using command line edition. This may be due to a memory cache bug
in the machine on which the problem has been found, but an other
solution is possible.

This patch proposes to avoid touching directly the pixel frame buffer
and to rebuild each character using the standard putc() function
on command line edition.

The resulting code is smaller and not obviously slower (no read
access to the pixel frame buffer).

Tested on a Cubox (ARM Marvell Dove 88AP510 SoC).

Signed-off-by: Jean-François Moine 
Signed-off-by: Greg Kroah-Hartman

tty: Move the handling of the tty release logic

2012-07-17T16:13:38+00:00

Now that we don't have tty->termios tied to drivers->tty we can untangle
the logic here. In addition we can push the removal logic out of the
destructor path.

At that point we can think about sorting out tty_port and console and all
the other ugly hangovers.

Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: move the termios object into the tty

2012-07-16T20:00:41+00:00

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case

Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

TTY: vt, add ->install

2012-06-14T00:30:53+00:00

We need to initialize the console only on the first open. This is
usually what is done in the ->install hook. vt used to do this in
->open. Now we move it to ->install and use newly added helper for
install: tty_port_install. It ensures tty->port to be set properly.

Signed-off-by: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

TTY: vt, remove con_schedule_flip

2012-06-14T00:30:53+00:00

This is identical to tty_schedule_flip. So let us use that instead.

Signed-off-by: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

Merge 3.4-rc3 into tty-next

2012-04-18T22:57:31+00:00

This allows us to pick up some changes needed for other serial patches.

Signed-off-by: Greg Kroah-Hartman