Commit Graph

364 Commits

Author SHA1 Message Date
Nicolas Pitre
ff78538e07 vt: add missing notification when switching back to text mode
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>
2025-06-19 13:27:16 +02:00
Nicolas Pitre
80fa7a0337 vt: bracketed paste support
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>
2025-05-21 13:41:03 +02:00
Nicolas Pitre
6802f3591f vt: make use of ucs_get_fallback() when glyph is unavailable
Attempt to display a fallback character when given character doesn't
have an available glyph. The substitution may not be as good as the
original character but still way more helpful than a squared question
mark.

Example substitutions: À -> A, ç -> c, ø -> o, ─ -> -, © -> C, etc.

See gen_ucs_fallback_table.py for a comprehensive list.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250507141535.40655-8-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 13:39:45 +02:00
Nicolas Pitre
bb9a151676 vt: move glyph determination to a separate function
No logical changes. Make it easier for enhancements to come.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250507141535.40655-4-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21 13:39:45 +02:00
Nicolas Pitre
68e7a421ab vt: make sure displayed double-width characters are remembered as such
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>
2025-05-21 13:39:45 +02:00
Nicolas Pitre
ffae2340a6 vt: remove zero-width-space handling from conv_uni_to_pc()
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>
2025-04-26 11:22:04 +02:00
Nicolas Pitre
5617aeb14a vt: pad double-width code points with a zero-width space
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>
2025-04-26 11:22:04 +02:00
Nicolas Pitre
b5c574995d vt: support Unicode recomposition
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>
2025-04-26 11:22:04 +02:00
Nicolas Pitre
95b05de0a5 vt: properly support zero-width Unicode code points
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>
2025-04-26 11:22:03 +02:00
Nicolas Pitre
07bc3f442f vt: move unicode processing to a separate file
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>
2025-04-26 11:22:03 +02:00
Nicolas Pitre
d066989a3d vt: minor cleanup to vc_translate_unicode()
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>
2025-04-26 11:22:03 +02:00
Greg Kroah-Hartman
3702f72748 Revert "vt: minor cleanup to vc_translate_unicode()"
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>
2025-04-26 11:21:26 +02:00
Greg Kroah-Hartman
e42e607aef Revert "vt: move unicode processing to a separate file"
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>
2025-04-26 11:21:25 +02:00
Greg Kroah-Hartman
d3e92076c1 Revert "vt: properly support zero-width Unicode code points"
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>
2025-04-26 11:21:24 +02:00
Greg Kroah-Hartman
3cf3987b57 Revert "vt: support Unicode recomposition"
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>
2025-04-26 11:21:18 +02:00
Greg Kroah-Hartman
7eaf91626e Revert "vt: pad double-width code points with a zero-white-space"
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>
2025-04-26 11:21:14 +02:00
Greg Kroah-Hartman
ab67c4622c Revert "vt: remove zero-white-space handling from conv_uni_to_pc()"
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>
2025-04-26 11:21:12 +02:00
Nicolas Pitre
b35f7a773c vt: remove zero-white-space handling from conv_uni_to_pc()
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>
2025-04-11 16:55:55 +02:00
Nicolas Pitre
547f57b88d vt: pad double-width code points with a zero-white-space
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>
2025-04-11 16:55:55 +02:00
Nicolas Pitre
cd6937d42b vt: support Unicode recomposition
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.

With all the infrastructure in place this is now trivial to do.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250410011839.64418-9-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11 16:55:55 +02:00
Nicolas Pitre
e88391f730 vt: properly support zero-width Unicode code points
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 doubles the width
of the preceding single-width code point. We handle that case by giving
VS16 a width of 1 when that happens.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250410011839.64418-4-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11 16:55:54 +02:00
Nicolas Pitre
2acaf27cd7 vt: move unicode processing to a separate file
This will make it easier to maintain. Also make it depend on
CONFIG_CONSOLE_TRANSLATIONS.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250410011839.64418-3-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11 16:55:54 +02:00
Nicolas Pitre
74045f6658 vt: minor cleanup to vc_translate_unicode()
Make it clearer when a sequence is bad.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Link: https://lore.kernel.org/r/20250410011839.64418-2-nico@fluxnic.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11 16:55:54 +02:00
Thomas Gleixner
8fa7292fee treewide: Switch/rename to timer_delete[_sync]()
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-05 10:30:12 +02:00
Günther Noack
2f83e38a09 tty: Permit some TIOCL_SETSEL modes without CAP_SYS_ADMIN
With this, processes without CAP_SYS_ADMIN are able to use TIOCLINUX with
subcode TIOCL_SETSEL, in the selection modes TIOCL_SETPOINTER,
TIOCL_SELCLEAR and TIOCL_SELMOUSEREPORT.

TIOCL_SETSEL was previously changed to require CAP_SYS_ADMIN, as this IOCTL
let callers change the selection buffer and could be used to simulate
keypresses.  These three TIOCL_SETSEL selection modes, however, are safe to
use, as they do not modify the selection buffer.

This fixes a mouse support regression that affected Emacs (invisible mouse
cursor).

Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/ee3ec63269b43b34e1c90dd8c9743bf8@finder.org
Fixes: 8d1b43f6a6 ("tty: Restrict access to TIOCLINUX' copy-and-paste subcommands")
Signed-off-by: Günther Noack <gnoack@google.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250110142122.1013222-1-gnoack@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13 06:46:50 +01:00
Jeongjun Park
f956052e00 vt: prevent kernel-infoleak in con_font_get()
font.data may not initialize all memory spaces depending on the implementation
of vc->vc_sw->con_font_get. This may cause info-leak, so to prevent this, it
is safest to modify it to initialize the allocated memory space to 0, and it
generally does not affect the overall performance of the system.

Cc: stable@vger.kernel.org
Reported-by: syzbot+955da2d57931604ee691@syzkaller.appspotmail.com
Fixes: 05e2600cb0 ("VT: Bump font size limitation to 64x128 pixels")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Link: https://lore.kernel.org/r/20241010174619.59662-1-aha310510@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-11 08:27:36 +02:00
Linus Torvalds
6bd23e0c2b tty: add the option to have a tty reject a new ldisc
... and use it to limit the virtual terminals to just N_TTY.  They are
kind of special, and in particular, the "con_write()" routine violates
the "writes cannot sleep" rule that some ldiscs rely on.

This avoids the

   BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659

when N_GSM has been attached to a virtual console, and gsmld_write()
calls con_write() while holding a spinlock, and con_write() then tries
to get the console lock.

Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Starke <daniel.starke@siemens.com>
Reported-by: syzbot <syzbot+dbac96d8e73b61aa559c@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=dbac96d8e73b61aa559c
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240423163339.59780-1-torvalds@linux-foundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-04 18:45:11 +02:00
Linus Torvalds
3bcb0bf65c TTY/Serial driver update for 6.9-rc1
Here is the big set of TTY/Serial driver updates and cleanups for
 6.9-rc1.  Included in here are:
   - more tty cleanups from Jiri
   - loads of 8250 driver cleanups from Andy
   - max310x driver updates
   - samsung serial driver updates
   - uart_prepare_sysrq_char() updates for many drivers
   - platform driver remove callback void cleanups
   - stm32 driver updates
   - other small tty/serial driver updates
 
 All of these have been in linux-next for a long time with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial driver updates from Greg KH:
 "Here is the big set of TTY/Serial driver updates and cleanups for
  6.9-rc1. Included in here are:

   - more tty cleanups from Jiri

   - loads of 8250 driver cleanups from Andy

   - max310x driver updates

   - samsung serial driver updates

   - uart_prepare_sysrq_char() updates for many drivers

   - platform driver remove callback void cleanups

   - stm32 driver updates

   - other small tty/serial driver updates

  All of these have been in linux-next for a long time with no reported
  issues"

* tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
  dt-bindings: serial: stm32: add power-domains property
  serial: 8250_dw: Replace ACPI device check by a quirk
  serial: Lock console when calling into driver before registration
  serial: 8250_uniphier: Switch to use uart_read_port_properties()
  serial: 8250_tegra: Switch to use uart_read_port_properties()
  serial: 8250_pxa: Switch to use uart_read_port_properties()
  serial: 8250_omap: Switch to use uart_read_port_properties()
  serial: 8250_of: Switch to use uart_read_port_properties()
  serial: 8250_lpc18xx: Switch to use uart_read_port_properties()
  serial: 8250_ingenic: Switch to use uart_read_port_properties()
  serial: 8250_dw: Switch to use uart_read_port_properties()
  serial: 8250_bcm7271: Switch to use uart_read_port_properties()
  serial: 8250_bcm2835aux: Switch to use uart_read_port_properties()
  serial: 8250_aspeed_vuart: Switch to use uart_read_port_properties()
  serial: port: Introduce a common helper to read properties
  serial: core: Add UPIO_UNKNOWN constant for unknown port type
  serial: core: Move struct uart_port::quirks closer to possible values
  serial: sh-sci: Call sci_serial_{in,out}() directly
  serial: core: only stop transmit when HW fifo is empty
  serial: pch: Use uart_prepare_sysrq_char().
  ...
2024-03-21 12:44:10 -07:00
Nicolas Pitre
1581dafaf0 vt: fix unicode buffer corruption when deleting characters
This is the same issue that was fixed for the VGA text buffer in commit
39cdb68c64 ("vt: fix memory overlapping when deleting chars in the
buffer"). The cure is also the same i.e. replace memcpy() with memmove()
due to the overlaping buffers.

Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Fixes: 81732c3b2f ("tty vt: Fix line garbage in virtual console on command line edition")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/sn184on2-3p0q-0qrq-0218-895349s4753o@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-02 23:09:04 +01:00
Roman Žilka
8524788abf tty/vt: Corrected doc of vc_sanitize_unicode(), vc_translate_unicode()
Corrected the doc of vc_sanitize_unicode() and vc_translate_unicode(),
tightly coupled functions which parse UTF-8 byte sequences.
1. Desc. of @rescan corresponded to the meaning of the return value -1.
   Corrected + added "Return:" section.
2. Replaced the ambiguous "character" with "code point" or "byte".

Signed-off-by: Roman Žilka <roman.zilka@gmail.com>
Link: https://lore.kernel.org/r/bee9faa8-0ea7-4411-bf77-3cb2e06385c7@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-17 17:44:46 +01:00
Jiri Slaby (SUSE)
6cc3028f79 tty: vt: decrypt magic constants in vc_is_control()
0x0d00ff81 and 0x0800f501 are bitmasks of ASCII characters. Spell them
explicitly using BIT() + ASCII constants. GENMASK() is used for the
9-bit range in CTRL_ACTION.

This also modifies the 'if' checking if the masks should be applied.
>From a "random" ' ' to the actual size of the bitmasks' type.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-23-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
3701400a39 tty: vt: use ASCII enum constants in vt_console_print()
There are still numbers used for ASCII characters in vt_console_print().
As we have an ASCII enum now, use the constant names from the enum
instead.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-22-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
137eb9ad22 tty: vt: use switch+case in the ESgetpars case
To be uniform in the 'c' handling, use switch-case (with ranges) even in
the ESgetpars case in do_con_trol().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-21-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
3d5f5b9711 tty: vt: use switch+case in the ESnonstd case
To be uniform in the 'c' handling, use switch-case (with ranges) even in
the ESnonstd case in do_con_trol().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-20-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
798d8b1cfe tty: vt: add new helper for reseting vc parameters
The code to reset the vc parameter parsing is repeated on two locations.
Create a helper vc_reset_params() and use it on both of them.

And instead of a 'for' loop to clear the array of parameters, use
simpler memset().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-19-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
bc9d077a8d tty: vt: handle CSI+[ inside preexisting switch-case
In do_con_trol()'s ESsquare case, there is already a switch (c). It is
preceded by an 'if (c == '[')'. Despite this 'if' handles a state
transition and not a modifier, move it as one of the switch cases. This
makes all the 'c' decision making more obvious there.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-18-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
fd5b40251a tty: vt: simplify ansi_control_string()
Given all the ANSI control states are sequential in the vc_ctl_state
enum, we can define first/last constants and use them in
ansi_control_string(). It makes the test simple and allows for removal
of the 'if' (which was unnecessary at all -- the 'return' should have
returned the 'if' content directly anyway).

And remove the useless comment -- it's clear from the function
prototype.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-17-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
22795b3c47 tty: vt: name, reflow and document enum vc_ctl_state
The enum for states is currently compact and undocumented. Put each
definition on a separate line and document them all using kernel-doc.

Document the same on the use sites.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-16-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:39 +00:00
Jiri Slaby (SUSE)
7c1c9c1494 tty: vt: move CSI ECMA handling to a separate function
Similar to previous moves, move also "CSI ..." (i.e. vc_priv == EPecma)
handling to a separate function.

This is the last large move of code out of do_con_trol(). And despite it
is still 151 lines of code (down from 407!), it is now quite easy to
folllow the transitions of the state machine in there. ESnonstd and
ESpalette handling still can be moved away, but it won't improve that
much.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-15-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
de0f61f342 tty: vt: move CSI DEC handling to a separate function
The handling of "CSI ? ..." (i.e. vc_priv == EPdec) can be easily moved
out of do_con_trol() into a separate function. This again increases
readability of do_con_trol().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-14-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
a9ffb22347 tty: vt: separate ESesc state handling into handle_esc()
Similar to the ASCII handling, the ESC handling can be easily moved away
from do_con_trol(). So create a new handle_esc() for that.

And add a comment with an example.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-13-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
ce66f8e387 tty: vt: extract ascii handling to handle_ascii()
To make the do_con_trol() a bit more understandable, extract the ASCII
handling (the switch-case) to a separate function.

Other nested switch-cases will follow in the next patches.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-12-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
a8ccce55a8 tty: vt: accept u8 in do_con_trol() and vc_setGx()
These functions expect u8 as the control character. Switch the type from
'int' appropriately. The caller passing the value (do_con_write()) is
fixed as well.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-11-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
9156792bcf tty: vt: put cases on separate lines
Some cases of the CSI switch are stuffed on one line. Put them all to a
separate line as is dictated by the coding style (and for better
readability).

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-10-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
cc8539cab4 tty: vt: rename setterm_command() to csi_RSB()
It follows naming of other similar functions. RSB stands here for Right
Square Bracket as (obviously) ']' cannot be in the function name.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-9-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
f9ac8d4e9f tty: vt: define an enum for CSI+] codes
Decrypt the constant values by proper enum names. This time in
setterm_command() (to be renamed to csi_RSB() in the next patches).

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-8-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:38 +00:00
Jiri Slaby (SUSE)
0afaeb78d1 tty: vt: move CSI+n handling along to other ECMA CSIs
CSIs without [<=>?] modifiers (ECMA) are handled in the switch-case
below this DEC switch+case handler. So move this ECMA CSI+n there too as
it fits there better.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-7-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:37 +00:00
Jiri Slaby (SUSE)
9abe9bf574 tty: vt: remove unneeded assignment of EPecma to vc_priv
vc_data::vc_priv is _always_ assigned before the ESgetpars case is
entered (in ESsquare). Therefore, there is no need to reset it when
leaving the ESgetpars case. Note the state is set to ESnormal few lines
above, so ESgetpars is entered only by the next CSI.

Therefore, this obfuscation can be removed.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:37 +00:00
Jiri Slaby (SUSE)
58d1af9319 tty: vt: split DEC CSI+h/l handling into csi_DEC_hl()
The DEC and ECMA handling of CSI+h/l is needlessly complicated. Split
these two, so that DEC is handled when the state is EPdec ('CSI ?' was
seen) and ECMA is handled in the EPecma state (no '?').

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:37 +00:00
Jiri Slaby (SUSE)
69b2c2693a tty: vt: rename set_mode() to csi_hl()
It's how the other CSI handling functions are named, so unify to that.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-06 14:37:37 +00:00