Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted

Pull media updates from Mauro Carvalho Chehab:

 - v4l2-core: added ISP statistics support and per-block validation

 - v4l2-core: Allow unknown HDR10 white point and luminance

 - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor

 - New codec: Milos: VPU v2.0 codec support

 - isp driver: gained support for Dreamchip RPPX1 ISP framework

 - vsp1 driver: gained support for RZ/T2H and RZ/N2H

 - Novalake driver: gained CVS support for new NVL hardware

 - dvb-core: fix feed leak on failed DMX_ADD_PID

 - several driver fixes, cleanups and minor improvements

* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
  media: ipu-bridge: check all DMI entries when overriding sensor rotation
  media: v4l2-async: avoid deleting unlinked ASC entry on link error
  media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
  media: intel/ipu6: fix async notifier cleanup leak on parse error
  media: staging/ipu7: fix async notifier UAF on probe error path
  media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
  media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
  media: rcar-isp: Fix VSPX reference leaks
  media: rcar-isp: Release ISPCORE resources
  media: i2c: imx415: Release runtime PM reference on VBLANK error
  media: i2c: imx415: Return test pattern write errors
  media: renesas: vsp1: Declare index variables in for loop statement
  media: renesas: vsp1: Make reset control optional to support platforms without a reset line
  media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
  media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
  media: nxp: imx8-isi: Add additional 32-bit RGB format support
  media: nxp: imx8-isi: Add 16-bit raw Bayer format support
  media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
  media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
  media: nxp: imx8-isi: Correct color map between V4L2 and ISI
  ...

1 files changed, 91 insertions, 0 deletions

diff --git a/Documentation/security/sak.rst b/Documentation/security/sak.rst
new file mode 100644
index 000000000..260e1d368
--- /dev/null
+++ b/Documentation/security/sak.rst
@@ -0,0 +1,91 @@
+=========================================
+Linux Secure Attention Key (SAK) handling
+=========================================
+
+:Date: 18 March 2001
+:Author: Andrew Morton
+
+An operating system's Secure Attention Key is a security tool which is
+provided as protection against trojan password capturing programs.  It
+is an undefeatable way of killing all programs which could be
+masquerading as login applications.  Users need to be taught to enter
+this key sequence before they log in to the system.
+
+From the PC keyboard, Linux has two similar but different ways of
+providing SAK.  One is the ALT-SYSRQ-K sequence.  You shouldn't use
+this sequence.  It is only available if the kernel was compiled with
+sysrq support.
+
+The proper way of generating a SAK is to define the key sequence using
+``loadkeys``.  This will work whether or not sysrq support is compiled
+into the kernel.
+
+SAK works correctly when the keyboard is in raw mode.  This means that
+once defined, SAK will kill a running X server.  If the system is in
+run level 5, the X server will restart.  This is what you want to
+happen.
+
+What key sequence should you use? Well, CTRL-ALT-DEL is used to reboot
+the machine.  CTRL-ALT-BACKSPACE is magical to the X server.  We'll
+choose CTRL-ALT-PAUSE.
+
+In your rc.sysinit (or rc.local) file, add the command::
+
+	echo "control alt keycode 101 = SAK" | /bin/loadkeys
+
+And that's it!  Only the superuser may reprogram the SAK key.
+
+
+.. note::
+
+  1. Linux SAK is said to be not a "true SAK" as is required by
+     systems which implement C2 level security.  This author does not
+     know why.
+
+
+  2. On the PC keyboard, SAK kills all applications which have
+     /dev/console opened.
+
+     Unfortunately this includes a number of things which you don't
+     actually want killed.  This is because these applications are
+     incorrectly holding /dev/console open.  Be sure to complain to your
+     Linux distributor about this!
+
+     You can identify processes which will be killed by SAK with the
+     command::
+
+	# ls -l /proc/[0-9]*/fd/* | grep console
+	l-wx------    1 root     root           64 Mar 18 00:46 /proc/579/fd/0 -> /dev/console
+
+     Then::
+
+	# ps aux|grep 579
+	root       579  0.0  0.1  1088  436 ?        S    00:43   0:00 gpm -t ps/2
+
+     So ``gpm`` will be killed by SAK.  This is a bug in gpm.  It should
+     be closing standard input.  You can work around this by finding the
+     initscript which launches gpm and changing it thusly:
+
+     Old::
+
+	daemon gpm
+
+     New::
+
+	daemon gpm < /dev/null
+
+     Vixie cron also seems to have this problem, and needs the same treatment.
+
+     Also, one prominent Linux distribution has the following three
+     lines in its rc.sysinit and rc scripts::
+
+	exec 3<&0
+	exec 4>&1
+	exec 5>&2
+
+     These commands cause **all** daemons which are launched by the
+     initscripts to have file descriptors 3, 4 and 5 attached to
+     /dev/console.  So SAK kills them all.  A workaround is to simply
+     delete these lines, but this may cause system management
+     applications to malfunction - test everything well.
+