linux.git/drivers/tty/vt/vt.c, branch v5.1 Linux kernel source tree vt: fix cursor when clearing the screen 2019-04-17T12:45:15+00:00 Mikulas Patocka mpatocka@redhat.com 2019-04-05T00:53:28+00:00 b2ecf00631362a83744e5ec249947620db5e240c The patch a6dbe4427559 ("vt: perform safe console erase in the right order") introduced a bug. The conditional do_update_region() was replaced by a call to update_region() that does contain the conditional already, but with unwanted extra side effects such as restoring the cursor drawing. In order to reproduce the bug: - use framebuffer console with the AMDGPU driver - type "links" to start the console www browser - press 'q' and space to exit links Now the cursor will be permanently visible in the center of the screen. It will stay there until something overwrites it. The bug goes away if we change update_region() back to the conditional do_update_region(). [ nico: reworded changelog ] Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Cc: stable@vger.kernel.org Fixes: a6dbe4427559 ("vt: perform safe console erase in the right order") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The patch a6dbe4427559 ("vt: perform safe console erase in the right
order") introduced a bug. The conditional do_update_region() was
replaced by a call to update_region() that does contain the conditional
already, but with unwanted extra side effects such as restoring the cursor
drawing.

In order to reproduce the bug:
- use framebuffer console with the AMDGPU driver
- type "links" to start the console www browser
- press 'q' and space to exit links

Now the cursor will be permanently visible in the center of the
screen. It will stay there until something overwrites it.

The bug goes away if we change update_region() back to the conditional
do_update_region().

[ nico: reworded changelog ]

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Cc: stable@vger.kernel.org
Fixes: a6dbe4427559 ("vt: perform safe console erase in the right order")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: perform safe console erase in the right order 2019-02-12T09:46:11+00:00 Nicolas Pitre nicolas.pitre@linaro.org 2019-02-12T00:36:41+00:00 a6dbe442755999960ca54a9b8ecfd9606be0ea75 Commit 4b4ecd9cb853 ("vt: Perform safe console erase only once") removed what appeared to be an extra call to scr_memsetw(). This missed the fact that set_origin() must be called before clearing the screen otherwise old screen content gets restored on the screen when using vgacon. Let's fix that by moving all the scrollback handling to flush_scrollback() where it logically belongs, and invoking it before the actual screen clearing in csi_J(), making the code simpler in the end. Reported-by: Matthew Whitehead <tedheadster@gmail.com> Signed-off-by: Nicolas Pitre <nico@linaro.org> Tested-by: Matthew Whitehead <tedheadster@gmail.com> Fixes: 4b4ecd9cb853 ("vt: Perform safe console erase only once") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Commit 4b4ecd9cb853 ("vt: Perform safe console erase only once") removed
what appeared to be an extra call to scr_memsetw(). This missed the fact
that set_origin() must be called before clearing the screen otherwise
old screen content gets restored on the screen when using vgacon. Let's
fix that by moving all the scrollback handling to flush_scrollback()
where it logically belongs, and invoking it before the actual screen
clearing in csi_J(), making the code simpler in the end.

Reported-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Matthew Whitehead <tedheadster@gmail.com>
Fixes: 4b4ecd9cb853 ("vt: Perform safe console erase only once")
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge 5.0-rc4 into tty-next 2019-01-28T07:22:00+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2019-01-28T07:22:00+00:00 83b21ed0fc2a7b17c6b9d4f72f664841f797380b We need the tty and serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We need the tty and serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: ignore sequences that contain ':' in parameters. 2019-01-18T12:57:27+00:00 Martin Hostettler textshell@uchuujin.de 2018-12-15T14:34:23+00:00 04afcd3aaf3389cc258044350e4daac2410164d8 csi sequences can contain subparameters delimited by ':' characters. For now just ignore the whole sequence in this case. Such sequences are used by more capable terminal implementations with T.416 high color modes or extended underline rendition attributes. Also ignore sequences with private use characters '?', '>', '=' and '>' that are not at the initial position. Signed-off-by: Martin Hostettler <textshell@uchuujin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
csi sequences can contain subparameters delimited by ':' characters. For
now just ignore the whole sequence in this case. Such sequences are used by
more capable terminal implementations with T.416 high color modes or
extended underline rendition attributes.

Also ignore sequences with private use characters '?', '>', '='
and '>' that are not at the initial position.

Signed-off-by: Martin Hostettler <textshell@uchuujin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: ignore csi sequences with intermediate characters. 2019-01-18T12:57:27+00:00 Martin Hostettler textshell@uchuujin.de 2018-12-15T14:34:22+00:00 7a99565f87321b456e3469b8e256705f605997d5 Various csi sequences contain intermediate characters between the parameters and the final character. Introduce a additional state that cleanly ignores these sequences. This allows the vt to ignore these sequences used by more capable terminal implementations such as "request mode", etc. Signed-off-by: Martin Hostettler <textshell@uchuujin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Various csi sequences contain intermediate characters between the
parameters and the final character. Introduce a additional state that
cleanly ignores these sequences.

This allows the vt to ignore these sequences used by more capable
terminal implementations such as "request mode", etc.

Signed-off-by: Martin Hostettler <textshell@uchuujin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: Implement parsing for >, =, < private sequences. 2019-01-18T12:56:41+00:00 Martin Hostettler textshell@uchuujin.de 2018-12-15T14:34:21+00:00 5445447b62e0cf69a6f8b62df51c1ef6f2cd56fe Private sequences can start with '>', '=' and (in theory) '<'. Implement correct parsing for these. The newly parsable sequences are cleanly ignored as it is customary with terminal emulators. This allows the vt to ignore various sequences used by more capable terminal implementations such as "Secondary Device Attributes", "Tertiary Device Attributes" and various advanced configuration commands that don't have dedicated terminfo entries. Signed-off-by: Martin Hostettler <textshell@uchuujin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Private sequences can start with '>', '=' and (in theory) '<'.
Implement correct parsing for these. The newly parsable sequences are
cleanly ignored as it is customary with terminal emulators.

This allows the vt to ignore various sequences used by more capable
terminal implementations such as "Secondary Device Attributes",
"Tertiary Device Attributes" and various advanced configuration commands
that don't have dedicated terminfo entries.

Signed-off-by: Martin Hostettler <textshell@uchuujin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: refactor vc_ques to allow of other private sequences. 2019-01-18T12:52:41+00:00 Martin Hostettler textshell@uchuujin.de 2018-12-15T14:34:20+00:00 2ff5c5a1dc6e6c502e0a3e49db4e792804e43693 The vc_ques keeps track if a csi sequence is a private DEC control function beginning with '?'. Nowadays some private control functions begin with '>' and '='. Switch the code to instead use a new 3-bit vc_priv that allows for all private use parameter prefixes. Signed-off-by: Martin Hostettler <textshell@uchuujin.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The vc_ques keeps track if a csi sequence is a private DEC control
function beginning with '?'. Nowadays some private control functions
begin with '>' and '='. Switch the code to instead use a new 3-bit
vc_priv that allows for all private use parameter prefixes.

Signed-off-by: Martin Hostettler <textshell@uchuujin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: annotate implicit fall throughs 2019-01-18T12:48:52+00:00 Mathieu Malaterre malat@debian.org 2019-01-14T20:41:13+00:00 17504fd7db0c6c32fda8c46ff42ddd871b259e54 There is a plan to build the kernel with -Wimplicit-fallthrough and these places in the code produced warnings (W=1). Fix them up. This commit remove the following warning: drivers/tty/vt/vt.c:2112:6: warning: this statement may fall through [-Wimplicit-fallthrough=] drivers/tty/vt/vt.c:2237:6: warning: this statement may fall through [-Wimplicit-fallthrough=] Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
There is a plan to build the kernel with -Wimplicit-fallthrough and
these places in the code produced warnings (W=1). Fix them up.

This commit remove the following warning:

  drivers/tty/vt/vt.c:2112:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
  drivers/tty/vt/vt.c:2237:6: warning: this statement may fall through [-Wimplicit-fallthrough=]

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vcsa: clamp header values when they don't fit 2019-01-18T12:47:55+00:00 Nicolas Pitre nicolas.pitre@linaro.org 2019-01-09T03:55:02+00:00 8a085494317cab6fef25b34521dae03c83f31eaa The /dev/vcsa* devices have a fixed char-sized header that stores the screen geometry and cursor location. Let's make sure it doesn't contain random garbage when those values exceed 255. If ever it becomes necessary to convey larger screen info to user space then a larger header in the not-yet-implemented /dev/vcsua* devices should be considered. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The /dev/vcsa* devices have a fixed char-sized header that stores the
screen geometry and cursor location. Let's make sure it doesn't contain
random garbage when those values exceed 255. If ever it becomes necessary
to convey larger screen info to user space then a larger header in the
not-yet-implemented /dev/vcsua* devices should be considered.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt: invoke notifier on screen size change 2019-01-18T12:42:58+00:00 Nicolas Pitre nicolas.pitre@linaro.org 2019-01-09T03:55:01+00:00 0c9b1965faddad7534b6974b5b36c4ad37998f8e User space using poll() on /dev/vcs devices are not awaken when a screen size change occurs. Let's fix that. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
User space using poll() on /dev/vcs devices are not awaken when a
screen size change occurs. Let's fix that.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>