vsa.console is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

drivers/tty/vt/vt_ioctl.c:711 vt_ioctl() warn: potential spectre issue
'vc_cons' [r]

Fix this by sanitizing vsa.console before using it to index vc_cons

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull tty/serial driver updates from Greg KH:
 "Here is the big tty and serial driver pull request for 4.19-rc1.

  It's not all that big, just a number of small serial driver updates
  and fixes, along with some better vt handling for unicode characters
  for those using braille terminals.

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

* tag 'tty-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (73 commits)
  tty: serial: 8250: Revert NXP SC16C2552 workaround
  serial: 8250_exar: Read INT0 from slave device, too
  tty: rocket: Fix possible buffer overwrite on register_PCI
  serial: 8250_dw: Add ACPI support for uart on Broadcom SoC
  serial: 8250_dw: always set baud rate in dw8250_set_termios
  dt-bindings: serial: Add binding for uartlite
  tty: serial: uartlite: Add support for suspend and resume
  tty: serial: uartlite: Add clock adaptation
  tty: serial: uartlite: Add structure for private data
  serial: sh-sci: Improve support for separate TEI and DRI interrupts
  serial: sh-sci: Remove SCIx_RZ_SCIFA_REGTYPE
  serial: sh-sci: Allow for compressed SCIF address
  serial: sh-sci: Improve interrupts description
  serial: 8250: Use cached port name directly in messages
  serial: 8250_exar: Drop unused variable in pci_xr17v35x_setup()
  vt: drop unused struct vt_struct
  vt: avoid a VLA in the unicode screen scroll function
  vt: add /dev/vcsu* to devices.txt
  vt: coherence validation code for the unicode screen buffer
  vt: selection: take screen contents from uniscr if available
  ...

Pull LED updates from Jacek Anaszewski:
 "LED triggers improvements make the biggest part of this pull request.
  The most striking ones, that allowed for nice cleanups in the triggers
  are:

   - centralized handling of creation and removal of trigger sysfs
     attributes via attribute group

   - addition of module_led_trigger() helper

  The other things that need to be mentioned:

  New features and improvements to existing LED class drivers:

   - lt3593: add DT support, switch to gpiod interface

   - lm3692x: support LED sync configuration, change OF calls to fwnode
     calls

   - apu: modify PC Engines apu/apu2 driver to support apu3

  Change in the drivers/net/can/led.c:

   - mark led trigger as broken since it's in the way for the further
     cleanups. It implements a subset of the netdev trigger and an Ack
     is needed from someone who can actually test and confirm that the
     netdev trigger works for can devices"

* tag 'leds-for-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds: (32 commits)
  leds: ns2: Change unsigned to unsigned int
  usb: simplify usbport trigger
  leds: gpio trigger: simplifications from core changes
  leds: backlight trigger: simplifications from core changes
  leds: activity trigger: simplifications from core changes
  leds: default-on trigger: make use of module_led_trigger()
  leds: heartbeat trigger: simplifications from core changes
  leds: oneshot trigger: simplifications from core changes
  leds: transient trigger: simplifications from core changes
  leds: timer trigger: simplifications from core changes
  leds: netdev trigger: simplifications from core changes
  leds: triggers: new function led_set_trigger_data()
  leds: triggers: define module_led_trigger helper
  leds: triggers: handle .trigger_data and .activated() in the core
  leds: triggers: add device attribute support
  leds: triggers: let struct led_trigger::activate() return an error code
  leds: triggers: make the MODULE_LICENSE string match the actual license
  leds: lm3692x: Support LED sync configuration
  dt: bindings: lm3692x: Update binding for LED sync control
  leds: lm3692x: Change DT calls to fwnode calls
  ...

The nr argument is typically small: most often nr == 1. However this
could be abused with a very large explicit scroll in a resized screen.
Make the code scroll lines by performing an array rotation operation to
avoid the need for a large temporary space.

Requested-by: Kees Cook <keescook@chromium.org>
Suggested-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure the unicode screen buffer matches the video screen content.
This is provided for debugging convenience and disabled by default.

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

This preserves whatever was written even if we can't currently display the
given glyph.  Mouse paste won't corrupt any character of wcwidth() == 1
anymore.

Note that for now uniscr doesn't get allocated until something reads
/dev/vcsuN for that console, making this code dormant for most users.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Those above U+10FFFF get replaced with U+FFFD.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

All the helper function saved us was a cast.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This completes dead keys definitions for internationalization
completeness on the console.  The representatives have been chosen
coherently with libx11 compose sequences, which avoid symetry conflicts
(e.g. there is U with caron, but no c with breve).

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Given that activating a trigger can fail, let the callback return an
indication. This prevents to have a trigger active according to the
"trigger" sysfs attribute but not functional.

All users are changed accordingly to return 0 for now. There is no intended
change in behaviour.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>