Now that we've renamed probe_kernel_address() to get_kernel_nofault()
and made it look and behave more in line with get_user(), some of the
subtle type behavior differences end up being more obvious and possibly
dangerous.

When you do

        get_user(val, user_ptr);

the type of the access comes from the "user_ptr" part, and the above
basically acts as

        val = *user_ptr;

by design (except, of course, for the fact that the actual dereference
is done with a user access).

Note how in the above case, the type of the end result comes from the
pointer argument, and then the value is cast to the type of 'val' as
part of the assignment.

So the type of the pointer is ultimately the more important type both
for the access itself.

But 'get_kernel_nofault()' may now _look_ similar, but it behaves very
differently.  When you do

        get_kernel_nofault(val, kernel_ptr);

it behaves like

        val = *(typeof(val) *)kernel_ptr;

except, of course, for the fact that the actual dereference is done with
exception handling so that a faulting access is suppressed and returned
as the error code.

But note how different the casting behavior of the two superficially
similar accesses are: one does the actual access in the size of the type
the pointer points to, while the other does the access in the size of
the target, and ignores the pointer type entirely.

Actually changing get_kernel_nofault() to act like get_user() is almost
certainly the right thing to do eventually, but in the meantime this
patch adds logit to at least verify that the pointer type is compatible
with the type of the result.

In many cases, this involves just casting the pointer to 'void *' to
make it obvious that the type of the pointer is not the important part.
It's not how 'get_user()' acts, but at least the behavioral difference
is now obvious and explicit.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Better describe what this helper does, and match the naming of
copy_from_kernel_nofault.

Also switch the argument order around, so that it acts and looks
like get_user().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull more Kbuild updates from Masahiro Yamada:

 - fix build rules in binderfs sample

 - fix build errors when Kbuild recurses to the top Makefile

 - covert '---help---' in Kconfig to 'help'

* tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  treewide: replace '---help---' in Kconfig files with 'help'
  kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables
  samples: binderfs: really compile this sample and fix build issues

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

EFI on ARM only supports short descriptors, and given that it mandates
that the MMU and caches are on, it is implied that booting in HYP mode
is not supported.

However, implementations of EFI exist (i.e., U-Boot) that ignore this
requirement, which is not entirely unreasonable, given that it makes
HYP mode inaccessible to the operating system.

So let's make sure that we can deal with this condition gracefully.
We already tolerate booting the EFI stub with the caches off (even
though this violates the EFI spec as well), and so we should deal
with HYP mode boot with MMU and caches either on or off.

- When the MMU and caches are on, we can ignore the HYP stub altogether,
  since we can carry on executing at HYP. We do need to ensure that we
  disable the MMU at HYP before entering the kernel proper.

- When the MMU and caches are off, we have to drop to SVC mode so that
  we can set up the page tables using short descriptors. In this case,
  we need to install the HYP stub as usual, so that we can return to HYP
  mode before handing over to the kernel proper.

Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

ZBOOT_ROM_TEXT and ZBOOT_ROM_BSS are defined as 'hex' but had a default
of "0". Kconfig will helpfully expand a text entry of 0 to 0x0 but
because this is not the same as the default value it was treated as
being explicitly set when running 'make savedefconfig' so most arm
defconfigs have CONFIG_ZBOOT_ROM_TEXT=0x0 and CONFIG_ZBOOT_ROM_BSS=0x0.

Change the default to 0x0 which will mean next time the defconfigs are
re-generated the spurious config entries will be removed.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Redefine GZIP, BZIP2, LZOP variables as KGZIP, KBZIP2, KLZOP resp.
GZIP, BZIP2, LZOP env variables are reserved by the tools. The original
attempt to redefine them internally doesn't work in makefiles/scripts
intercall scenarios, e.g., "make GZIP=gzip bindeb-pkg" and results in
broken builds. There can be other broken build commands because of this,
so the universal solution is to use non-reserved env variables for the
compression tools.

Fixes: 8dfb61dcbace ("kbuild: add variables for compression tools")
Signed-off-by: Denis Efremov <efremov@linux.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pull READ/WRITE_ONCE rework from Will Deacon:
 "This the READ_ONCE rework I've been working on for a while, which
  bumps the minimum GCC version and improves code-gen on arm64 when
  stack protector is enabled"

[ Side note: I'm _really_ tempted to raise the minimum gcc version to
  4.9, so that we can just say that we require _Generic() support.

  That would allow us to more cleanly handle a lot of the cases where we
  depend on very complex macros with 'sizeof' or __builtin_choose_expr()
  with __builtin_types_compatible_p() etc.

  This branch has a workaround for sparse not handling _Generic(),
  either, but that was already fixed in the sparse development branch,
  so it's really just gcc-4.9 that we'd require.   - Linus ]

* 'rwonce/rework' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux:
  compiler_types.h: Use unoptimized __unqual_scalar_typeof for sparse
  compiler_types.h: Optimize __unqual_scalar_typeof compilation time
  compiler.h: Enforce that READ_ONCE_NOCHECK() access size is sizeof(long)
  compiler-types.h: Include naked type in __pick_integer_type() match
  READ_ONCE: Fix comment describing 2x32-bit atomicity
  gcov: Remove old GCC 3.4 support
  arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros
  locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros
  READ_ONCE: Drop pointer qualifiers when reading from scalar types
  READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses
  READ_ONCE: Simplify implementations of {READ,WRITE}_ONCE()
  arm64: csum: Disable KASAN for do_csum()
  fault_inject: Don't rely on "return value" from WRITE_ONCE()
  net: tls: Avoid assigning 'const' pointer to non-const pointer
  netfilter: Avoid assigning 'const' pointer to non-const pointer
  compiler/gcc: Raise minimum GCC version for kernel builds to 4.8

Pull clk updates from Stephen Boyd:
 "This time around we have four lines of diff in the core framework,
  removing a function that isn't used anymore. Otherwise the main new
  thing for the common clk framework is that it is selectable in the
  Kconfig language now. Hopefully this will let clk drivers and clk
  consumers be testable on more than the architectures that support the
  clk framework. The goal is to introduce some Kunit tests for the
  framework.

  Outside of the core framework we have the usual set of various driver
  updates and non-critical fixes. The dirstat shows that the new
  Baikal-T1 driver is the largest addition this time around in terms of
  lines of code. After that the x86 (Intel), Qualcomm, and Mediatek
  drivers introduce many lines to support new or upcoming SoCs. After
  that the dirstat shows the usual suspects working on their SoC support
  by fixing minor bugs, correcting data and converting some of their DT
  bindings to YAML.

  Core:
   - Allow the COMMON_CLK config to be selectable

  New Drivers:
   - Clk driver for Baikal-T1 SoCs
   - Mediatek MT6765 clock support
   - Support for Intel Agilex clks
   - Add support for X1830 and X1000 Ingenic SoC clk controllers
   - Add support for the new Renesas RZ/G1H (R8A7742) SoC
   - Add support for Qualcomm's MSM8939 Generic Clock Controller

  Updates:
   - Support IDT VersaClock 5P49V5925
   - Bunch of updates for HSDK clock generation unit (CGU) driver
   - Start making audio and GPU clks work on Marvell MMP2/MMP3 SoCs
   - Add some GPU, NPU, and UFS clks to Qualcomm SM8150 driver
   - Enable supply regulators for GPU gdscs on Qualcomm SoCs
   - Add support for Si5342, Si5344 and Si5345 chips
   - Support custom flags in Xilinx zynq firmware
   - Various small fixes to the Xilinx clk driver
   - A single minor rounding fix for the legacy Allwinner clock support
   - A few patches from Abel Vesa as preparation of adding audiomix
     clock support on i.MX
   - A couple of cleanups from Anson Huang for i.MX clk-sscg-pll and
     clk-pllv3 drivers
   - Drop dependency on ARM64 for i.MX8M clock driver, to support
     aarch32 mode on aarch64 hardware
   - A series from Peng Fan to improve i.MX8M clock drivers, using
     composite clock for core and bus clk slice
   - Set a better parent clock for flexcan on i.MX6UL to support CiA102
     defined bit rates
   - A couple changes for EMC frequency scaling on Tegra210
   - Support for CPU frequency scaling on Tegra20/Tegra30
   - New clk gate for CSI test pattern generator on Tegra210
   - Regression fixes for Samsung exynos542x and exynos5433 SoCs
   - Use of fallthrough; attribute for Samsung s3c24xx
   - Updates and fixup HDMI and video clocks on Meson8b
   - Fixup reset polarity on Meson8b
   - Fix GPU glitch free mux switch on Meson gx and g12
   - A minor fix for the currently unused suspend/resume handling on
     Renesas RZ/A1 and RZ/A2
   - Two more conversions of Renesas DT bindings to json-schema
   - Add support for the USB 2.0 clock selector on Renesas R-Car M3-W+"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (155 commits)
  clk: mediatek: Remove ifr{0,1}_cfg_regs structures
  clk: baikal-t1: remove redundant assignment to variable 'divider'
  clk: baikal-t1: fix spelling mistake "Uncompatible" -> "Incompatible"
  dt-bindings: clock: Add a missing include to MMP Audio Clock binding
  dt: Add bindings for IDT VersaClock 5P49V5925
  clk: vc5: Add support for IDT VersaClock 5P49V6965
  clk: Add Baikal-T1 CCU Dividers driver
  clk: Add Baikal-T1 CCU PLLs driver
  dt-bindings: clk: Add Baikal-T1 CCU Dividers binding
  dt-bindings: clk: Add Baikal-T1 CCU PLLs binding
  clk: mediatek: assign the initial value to clk_init_data of mtk_mux
  clk: mediatek: Add MT6765 clock support
  clk: mediatek: add mt6765 clock IDs
  dt-bindings: clock: mediatek: document clk bindings vcodecsys for Mediatek MT6765 SoC
  dt-bindings: clock: mediatek: document clk bindings mipi0a for Mediatek MT6765 SoC
  dt-bindings: clock: mediatek: document clk bindings for Mediatek MT6765 SoC
  CLK: HSDK: CGU: add support for 148.5MHz clock
  CLK: HSDK: CGU: support PLL bypassing
  CLK: HSDK: CGU: check if PLL is bypassed first
  clk: clk-si5341: Add support for the Si5345 series
  ...