The maximum number of keycodes got bumped to 256 a very long time ago,
but the default keymaps were never adjusted to match. This is causing
the kernel to interpret keycodes above 127 as U+0000 if the shipped
generated keymap is used.
Fix this by mapping all keycodes above 127 to K_HOLE so the kernel
ignores them.
The contents of this patche were generated by rerunning `loadkeys
--mktable --unicode` and only including the changes to map keycodes
above 127 to K_HOLE.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Myrrh Periwinkle <myrrhperiwinkle@qtmlabs.xyz>
Cc: stable <stable@kernel.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-2-c27e143cc2eb@qtmlabs.xyz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We don't process Unicode characters if the virtual terminal is in raw
mode, so there's no reason why we shouldn't do the same for K_OFF
(especially since people would expect K_OFF to actually turn off all VT
key processing).
Fixes: 9fc3de9c83 ("vt: Add virtual console keyboard mode OFF")
Signed-off-by: Myrrh Periwinkle <myrrhperiwinkle@qtmlabs.xyz>
Cc: stable <stable@kernel.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-1-c27e143cc2eb@qtmlabs.xyz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the correct function parameter name in ucs_get_fallback() to prevent
kernel-doc warnings:
Warning: drivers/tty/vt/ucs.c:218 function parameter 'cp' not described in 'ucs_get_fallback'
Warning: drivers/tty/vt/ucs.c:218 Excess function parameter 'base' description in 'ucs_get_fallback'
Fixes: fe26933cf1 ("vt: add ucs_get_fallback()")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Nicolas Pitre <npitre@baylibre.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: linux-serial@vger.kernel.org
Reviewed-by: Nicolas Pitre <npitre@baylibre.com>.
Link: https://lore.kernel.org/r/20250611020229.2650595-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Programs using poll() on /dev/vcsa to be notified when VT changes occur
were missing one case: the switch from gfx to text mode.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/9o5ro928-0pp4-05rq-70p4-ro385n21n723@onlyvoer.pbz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The console dimension and cursor position are available through the
/dev/vcsa interface already. However the /dev/vcsa header format uses
single-byte fields therefore those values are clamped to 255.
As surprizing as this may seem, some people do use 240-column 67-row
screens (a 1920x1080 monitor with 8x16 pixel fonts) which is getting
close to the limit. Monitors with higher resolution are not uncommon
these days (3840x2160 producing a 480x135 character display) and it is
just a matter of time before someone with, say, a braille display using
the Linux VT console and BRLTTY on such a screen reports a bug about
missing and oddly misaligned screen content.
Let's add VT_GETCONSIZECSRPOS for the retrieval of console size and cursor
position without byte-sized limitations. The actual console size limit as
encoded in vt.c is 32767x32767 so using a short here is appropriate. Then
this can be used to get the cursor position when /dev/vcsa reports 255.
The screen dimension may already be obtained using TIOCGWINSZ and adding
the same information to VT_GETCONSIZECSRPOS might be redundant. However
applications that care about cursor position also care about display
size and having 2 separate system calls to obtain them separately is
wasteful. Also, the cursor position can be queried by writing "\e[6n" to
a tty and reading back the result but that may be done only by the actual
application using that tty and not a sideline observer.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250520171851.1219676-3-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is comprised of 3 aspects:
- Take note of when applications advertise bracketed paste support via
"\e[?2004h" and "\e[?2004l".
- Insert bracketed paste markers ("\e[200~" and "\e[201~") around pasted
content in paste_selection() when bracketed paste is active.
- Add TIOCL_GETBRACKETEDPASTE to return bracketed paste status so user
space daemons implementing cut-and-paste functionality (e.g. gpm,
BRLTTY) may know when to insert bracketed paste markers.
Link: https://en.wikipedia.org/wiki/Bracketed-paste
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250520171851.1219676-2-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
They are listed amon those cmd values that "treat 'arg' as an integer"
which is wrong. They should instead fall into the default case. Probably
nobody ever relied on that code since 2009 but still.
Fixes: e92166517e ("tty: handle VT specific compat ioctls in vt driver")
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/pr214s15-36r8-6732-2pop-159nq85o48r7@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The generated table maps complex characters to their simpler fallback
forms for a terminal display when corresponding glyphs are unavailable.
A page-based approach is used to reduce compiled binary footprint.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250507141535.40655-6-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The generated table maps complex characters to their simpler fallback
forms for a terminal display when corresponding glyphs are unavailable.
This includes diacritics, symbols as well as many drawing characters.
Fallback characters aren't perfect replacements, obviously. But they are
still far more useful than a bunch of squared question marks.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250507141535.40655-5-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
And to do so we ensure the Unicode screen buffer is initialized when
double-width characters are encountered.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250507141535.40655-3-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The in_range() helper accepts a start and a length, not a start and
an end.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250507141535.40655-2-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add new dynamically generated headers to the local .gitignore.
Fixes: c2d2c5c0d6 ("vt: move UCS tables to the "shipped" form")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250430122917.72105-1-brgl@bgdev.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iQFSBAABCgA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmgOrWseHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGFyIH/AhXcuA8y8rk43mo
t+0GO7JR4dnr4DIl74GgDjCXlXiKCT7EXMfD/ABdofTxV4Pbyv+pUODlg1E6eO9U
C1WWM5PPNBGDDEVSQ3Yu756nr0UoiFhvW0R6pVdou5cezCWAtIF9LTN8DEUgis0u
EUJD9+/cHAMzfkZwabjm/HNsa1SXv2X47MzYv/PdHKr0htEPcNHF4gqBrBRdACGy
FJtaCKhuPf6TcDNXOFi5IEWMXrugReRQmOvrXqVYGa7rfUFkZgsAzRY6n/rUN5Z9
FAgle4Vlv9ohVYj9bXX8b6wWgqiKRpoN+t0PpRd6G6ict1AFBobNGo8LH3tYIKqZ
b/dCGNg=
=xDGd
-----END PGP SIGNATURE-----
Merge 6.15-rc4 into tty-next
We need the tty/serial fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the "shipped" mechanism to copy pre-generated tables to the build
tree by default. If GENERATE_UCS_TABLES=1 then they are generated at
build time instead. If GENERATE_UCS_TABLES=2 then
gen_ucs_recompose_table.py is invoked with --full.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-15-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Width tables are now split into BMP (16-bit) and non-BMP (above 16-bit).
This reduces the corresponding text size by 20-25%.
Note: scripts/checkpatch.pl complains about "... exceeds 100 columns".
Please ignore.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-14-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Split table ranges into BMP (16-bit) and non-BMP (above 16-bit).
This reduces the corresponding text size by 20-25%.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-13-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is now taken care of by ucs_is_zero_width().
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-12-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the Unicode screen buffer, we follow double-width code points with a
space to maintain proper column alignment. This, however, creates
semantic problems when e.g. using cut and paste.
Let's use a better code point for the column padding's purpose i.e. a
zero-width space rather than a full space. This way the combination
retains a width of 2.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-11-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Try replacing any decomposed Unicode sequence by the corresponding
recomposed code point. Code point to glyph correspondance works best
after recomposition, and this apply mostly to single-width code points
therefore we can't preserve them in their decomposed form anyway.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-10-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Table of base character + combining mark pairs with their precomposed
equivalents.
Note: scripts/checkpatch.pl complains about "... exceeds 100 columns".
Please ignore.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-9-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The generated table maps base character + combining mark pairs to their
precomposed equivalents using Python's unicodedata module.
The default script behavior is to create a table with most commonly used
Latin, Greek, and Cyrillic recomposition pairs only. It is much smaller
than the table with all possible recomposition pairs (71 entries vs 1000
entries). But if one needs/wants the full table then simply running the
script with the --full argument will generate it.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-8-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This removes the table from ucs.c and substitutes the generated tables
from ucs_width_table.h providing comprehensive ranges for double-width
and zero-width Unicode code points.
Also implements ucs_is_zero_width() to query the new zero-width table.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-7-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The table in ucs.c is terribly out of date and incomplete. We also need a
second table to store zero-width code points. Properly maintaining those
tables manually is impossible. So here's a script to generate them.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-5-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Zero-width Unicode code points are causing misalignment in vertically
aligned content, disrupting the visual layout. Let's handle zero-width
code points more intelligently.
Double-width code points are stored in the screen grid followed by a white
space code point to create the expected screen layout. When a double-width
code point is followed by a zero-width code point in the console incoming
bytestream (e.g., an emoji with a presentation selector) then we may
replace the white space padding by that zero-width code point instead of
dropping it. This maximize screen content information while preserving
proper layout.
If a zero-width code point is preceded by a single-width code point then
the above trick is not possible and such zero-width code point must
be dropped.
VS16 (Variation Selector 16, U+FE0F) is special as it typically doubles
the width of the preceding single-width code point. We handle that case
by giving VS16 a width of 1 instead of 0 when that happens.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-4-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This will make it easier to maintain. Also make it depend on
CONFIG_CONSOLE_TRANSLATIONS.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-3-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make it clearer when a sequence is bad.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-2-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 74045f6658.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 2acaf27cd7.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit e88391f730.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 26c94eb484.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 3a1ab63aa0.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit f2347b0cdf.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 54af55b990.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit cd6937d42b.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 119ff0b0f4.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit c7cb5b0779.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 547f57b88d.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit b35f7a773c.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 8bfabff0bf.
A new version of the series was submitted, so it's easier to revert the
old one and add the new one due to the changes invovled.
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we putting character to the tty, we take into account the keyboard
mode to properly handle utf8. This code is duplicated few times.
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/c0d10193e61f977b518862d8f216bbaf234138fd.1740141518.git.legion@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This requirement was overeagerly loosened in commit 2f83e38a09
("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN"), but as
it turns out,
(1) the logic I implemented there was inconsistent (apologies!),
(2) TIOCL_SELMOUSEREPORT might actually be a small security risk
after all, and
(3) TIOCL_SELMOUSEREPORT is only meant to be used by the mouse
daemon (GPM or Consolation), which runs as CAP_SYS_ADMIN
already.
In more detail:
1. The previous patch has inconsistent logic:
In commit 2f83e38a09 ("tty: Permit some TIOCL_SETSEL modes
without CAP_SYS_ADMIN"), we checked for sel_mode ==
TIOCL_SELMOUSEREPORT, but overlooked that the lower four bits of
this "mode" parameter were actually used as an additional way to
pass an argument. So the patch did actually still require
CAP_SYS_ADMIN, if any of the mouse button bits are set, but did not
require it if none of the mouse buttons bits are set.
This logic is inconsistent and was not intentional. We should have
the same policies for using TIOCL_SELMOUSEREPORT independent of the
value of the "hidden" mouse button argument.
I sent a separate documentation patch to the man page list with
more details on TIOCL_SELMOUSEREPORT:
https://lore.kernel.org/all/20250223091342.35523-2-gnoack3000@gmail.com/
2. TIOCL_SELMOUSEREPORT is indeed a potential security risk which can
let an attacker simulate "keyboard" input to command line
applications on the same terminal, like TIOCSTI and some other
TIOCLINUX "selection mode" IOCTLs.
By enabling mouse reporting on a terminal and then injecting mouse
reports through TIOCL_SELMOUSEREPORT, an attacker can simulate
mouse movements on the same terminal, similar to the TIOCSTI
keystroke injection attacks that were previously possible with
TIOCSTI and other TIOCL_SETSEL selection modes.
Many programs (including libreadline/bash) are then prone to
misinterpret these mouse reports as normal keyboard input because
they do not expect input in the X11 mouse protocol form. The
attacker does not have complete control over the escape sequence,
but they can at least control the values of two consecutive bytes
in the binary mouse reporting escape sequence.
I went into more detail on that in the discussion at
https://lore.kernel.org/all/20250221.0a947528d8f3@gnoack.org/
It is not equally trivial to simulate arbitrary keystrokes as it
was with TIOCSTI (commit 83efeeeb3d ("tty: Allow TIOCSTI to be
disabled")), but the general mechanism is there, and together with
the small number of existing legit use cases (see below), it would
be better to revert back to requiring CAP_SYS_ADMIN for
TIOCL_SELMOUSEREPORT, as it was already the case before
commit 2f83e38a09 ("tty: Permit some TIOCL_SETSEL modes without
CAP_SYS_ADMIN").
3. TIOCL_SELMOUSEREPORT is only used by the mouse daemons (GPM or
Consolation), and they are the only legit use case:
To quote console_codes(4):
The mouse tracking facility is intended to return
xterm(1)-compatible mouse status reports. Because the console
driver has no way to know the device or type of the mouse, these
reports are returned in the console input stream only when the
virtual terminal driver receives a mouse update ioctl. These
ioctls must be generated by a mouse-aware user-mode application
such as the gpm(8) daemon.
Jared Finder has also confirmed in
https://lore.kernel.org/all/491f3df9de6593df8e70dbe77614b026@finder.org/
that Emacs does not call TIOCL_SELMOUSEREPORT directly, and it
would be difficult to find good reasons for doing that, given that
it would interfere with the reports that GPM is sending.
More information on the interaction between GPM, terminals and the
kernel with additional pointers is also available in this patch:
https://lore.kernel.org/all/a773e48920aa104a65073671effbdee665c105fc.1603963593.git.tammo.block@gmail.com/
For background on who else uses TIOCL_SELMOUSEREPORT: Debian Code
search finds one page of results, the only two known callers are
the two mouse daemons GPM and Consolation. (GPM does not show up
in the search results because it uses literal numbers to refer to
TIOCLINUX-related enums. I looked through GPM by hand instead.
TIOCL_SELMOUSEREPORT is also not used from libgpm.)
https://codesearch.debian.net/search?q=TIOCL_SELMOUSEREPORT
Cc: Jared Finder <jared@finder.org>
Cc: Jann Horn <jannh@google.com>
Cc: Hanno Böck <hanno@hboeck.de>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: stable <stable@kernel.org>
Fixes: 2f83e38a09 ("tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN")
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20250411070144.3959-2-gnoack3000@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is now taken care of by ucs_is_zero_width(). And in the case where
we do want a padding from some zero-width code point then we should also
give the legacy displays a space character to work with.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/6o2ss437-6nps-s943-1n38-54np5587r08s@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the Unicode screen buffer, we follow double-width code points with a
space to maintain proper column alignment. This, however, creates
semantic problems when e.g. using cut and paste or selection.
Let's use a better code point for the column padding's purpose i.e. a
zero-white-space rather than a full space.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250410011839.64418-12-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
