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[PATCH 0/2] Persistent scrollback buffers for all VGA consoles

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  [PATCH 0/2] Persistent scrollback buffers for all VGA consoles Manuel Schölling <manuel.schoelling@gmx.de> - 2016-04-18 22:00 +0200
    Re: [PATCH 0/2] Persistent scrollback buffers for all VGA consoles Jakub Wilk <jwilk@jwilk.net> - 2016-04-19 00:00 +0200

#1382022 — [PATCH 0/2] Persistent scrollback buffers for all VGA consoles

Another attempt to add persistent scrollback buffers for all VGA consoles,
so the buffer is not flushed when swithing back and forth between consoles.

Note that breaks tools like bash's clear_console and thus might have
security implications:
clear_console relies on this 'anti-feature' of the kernel to clear the buffer
when consoles are switched.

To offer a way for userland tools to flush the buffer my second patch adds
a ioctl call for that.
Also this feature is disabled by default and security implications are clearly
stated in its documentation.

Manuel Schölling (2):
  console: Add persistent scrollback buffers for all VGA consoles
  console: Add ioctl for flushing the scrollback buffer

 drivers/tty/vt/vt_ioctl.c               |  20 ++++
 drivers/usb/misc/sisusbvga/sisusb_con.c |   1 +
 drivers/video/console/Kconfig           |  22 +++-
 drivers/video/console/dummycon.c        |   1 +
 drivers/video/console/mdacon.c          |   6 +
 drivers/video/console/newport_con.c     |   1 +
 drivers/video/console/sticon.c          |   7 ++
 drivers/video/console/vgacon.c          | 195 ++++++++++++++++++++++----------
 include/linux/console.h                 |   1 +
 include/uapi/linux/vt.h                 |   1 +
 10 files changed, 194 insertions(+), 61 deletions(-)

-- 
2.1.4

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#1382080

* Manuel Schölling <manuel.schoelling@gmx.de>, 2016-04-18, 21:56:
>To offer a way for userland tools to flush the buffer my second patch 
>adds a ioctl call for that.

In f8df13e0a901fe55631fed66562369b4dba40f8b, the escape sequence \e[3J 
was added, which erases the whole display including the scroll-back 
buffer. So the new ioctl shouldn't be necessary.

-- 
Jakub Wilk

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