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>
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>
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 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>
uart_port_lock() and uart_port_unlock() are (at the same time) defined
as:
* functions in include/linux/serial_core.h
* macros in drivers/tty/serial/serial_core.c
The former are sane uart port lock wrappers.
The latter _lock() does something completely different: it inspects
a uart_state, obtains a uart_port from it, and increases its reference
count. And if that all succeeded, the port is locked too.
Similarly, the _unlock() counterpart first unlocks and then decrements
the refcount too.
This state is REALLY CONFUSING.
So rename the latter (local .c macros):
* uart_port_lock() -> uart_port_ref_lock(), and
* uart_port_unlock() -> uart_port_unlock_deref().
Now, the forbidden while-at-it part: convert from a macro to an inline
-- do it here as the passed 'flags' have to be pointer to ulong now. So
we avoid doubled changes on identical LOCs.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250425111315.1036184-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mxser enables its PCI device with pcim_enable_device(). This,
implicitly, switches the function pci_request_region() into managed
mode, where it becomes a devres function.
The PCI subsystem wants to remove this hybrid nature from its
interfaces. To do so, users of the aforementioned combination of
functions must be ported to non-hybrid functions.
Replace the call to sometimes-managed pci_request_region() with one to
the always-managed pcim_request_region().
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://lore.kernel.org/r/20250417081333.20917-2-phasta@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the necessary callbacks(write_atomic, write_thread, device_lock
and device_unlock) and CON_NBCON flag to switch the sifive console
driver to perform as nbcon console.
Both ->write_atomic() and ->write_thread() will check for console
ownership whenever they are accessing registers.
The ->device_lock()/unlock() will provide the additional serilization
necessary for ->write_thread() which is called from dedicated printing
thread.
Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250412002544.185038-1-ryotkkr98@gmail.com
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>
The MSM UART DM controller supports different working modes, e.g. DMA or
the "single-character mode", where all reads/writes operate on a single
character rather than 4 chars (32-bit) at once. When using earlycon,
__msm_console_write() always writes 4 characters at a time, but we don't
know which mode the bootloader was using and we don't set the mode either.
This causes garbled output if the bootloader was using the single-character
mode, because only every 4th character appears in the serial console, e.g.
"[ 00oni pi 000xf0[ 00i s 5rm9(l)l s 1 1 SPMTA 7:C 5[ 00A ade k d[
00ano:ameoi .Q1B[ 00ac _idaM00080oo'"
If the bootloader was using the DMA ("DM") mode, output would likely fail
entirely. Later, when the full serial driver probes, the port is
re-initialized and output works as expected.
Fix this also for earlycon by clearing the DMEN register and
reset+re-enable the transmitter to apply the change. This ensures the
transmitter is in the expected state before writing any output.
Cc: stable <stable@kernel.org>
Fixes: 0efe729634 ("tty: serial: msm: Add earlycon support")
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250408-msm-serial-earlycon-v1-1-429080127530@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The aim here is to provide an easier support to more different SCI
controllers, like the RZ/T2H one.
The existing .data field of_sci_match is changed to a structure containing
all what that can be statically initialized, and avoid a call to
'sci_probe_regmap', in both 'sci_init_single', and 'early_console_setup'.
'sci_probe_regmap' is now assumed to be called in the only case where the
device description is from a board file instead of a dts.
In this way, there is no need to patch 'sci_probe_regmap' for adding new
SCI type, and also, the specific sci_port_params for a new SCI type can be
provided by an external file.
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Bultel <thierry.bultel.yh@bp.renesas.com>
Link: https://lore.kernel.org/r/20250403212919.1137670-10-thierry.bultel.yh@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The aim here is to prepare support for new sci controllers like
the T2H/RSCI whose registers are too much different for being
handled in common code.
This named serial controller also has 32 bits register,
so some return types had to be changed.
The needed generic functions are no longer static, with prototypes
defined in sh-sci-common.h so that they can be used from specific
implementation in a separate file, to keep this driver as little
changed as possible.
For doing so, a set of 'ops' is added to struct sci_port.
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Thierry Bultel <thierry.bultel.yh@bp.renesas.com>
Link: https://lore.kernel.org/r/20250403212919.1137670-9-thierry.bultel.yh@bp.renesas.com
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>
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>
