efi/libstub: zboot: do not use $(shell ...) in cmd_copy_and_pad

You do not need to use $(shell ...) in recipe lines, as they are already
executed in a shell. An alternative solution is $$(...), which is an
escaped sequence of the shell's command substituion, $(...).

For this case, there is a reason to avoid $(shell ...).

Kbuild detects command changes by using the if_changed macro, which
compares the previous command recorded in .*.cmd with the current
command from Makefile. If they differ, Kbuild re-runs the build rule.

To diff the commands, Make must expand $(shell ...) first. It means that
hexdump is executed every time, even when nothing needs rebuilding. If
Kbuild determines that vmlinux.bin needs rebuilding, hexdump will be
executed again to evaluate the 'cmd' macro, one more time to really
build vmlinux.bin, and finally yet again to record the expanded command
into .*.cmd.

Replace $(shell ...) with $$(...) to avoid multiple, unnecessay shell
evaluations. Since Make is agnostic about the shell code, $(...), the
if_changed macro compares the string "$(hexdump -s16 -n4 ...)" verbatim,
so hexdump is run only for building vmlinux.bin.

For the same reason, $(shell ...) in EFI_ZBOOT_OBJCOPY_FLAGS should be
eliminated.

While I was here, I replaced '&&' with ';' because a command for
if_changed is executed with 'set -e'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20231218080127.907460-1-masahiroy@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

efi/zboot: arm64: Inject kernel code size symbol into the zboot payload

The EFI zboot code is not built as part of the kernel proper, like the
ordinary EFI stub, but still needs access to symbols that are defined
only internally in the kernel, and are left unexposed deliberately to
avoid creating ABI inadvertently that we're stuck with later.

So capture the kernel code size of the kernel image, and inject it as an
ELF symbol into the object that contains the compressed payload, where
it will be accessible to zboot code that needs it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>

efi/zboot: Set forward edge CFI compat header flag if supported

Add some plumbing to the zboot EFI header generation to set the newly
introduced DllCharacteristicsEx flag associated with forward edge CFI
enforcement instructions (BTI on arm64, IBT on x86)

x86 does not currently uses the zboot infrastructure, so let's wire it
up only for arm64.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arm64: efi: enable generic EFI compressed boot

Wire up the generic EFI zboot support for arm64.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: boot: add zstd support

Support build the zstd compressed Image.zst. Similar as other
compressed formats, the Image.zst is not self-decompressing and
the bootloader still needs to handle decompression before
launching the kernel image.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20220619170657.2657-1-jszhang@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

arm64: move the (z)install rules to arch/arm64/Makefile

Currently, the (z)install targets in arch/arm64/Makefile descend into
arch/arm64/boot/Makefile to invoke the shell script, but there is no
good reason to do so.

arch/arm64/Makefile can run the shell script directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210729140527.443116-1-masahiroy@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'

Since v4.3-rc1 commit 0723c05fb75e44 ("arm64: enable more compressed
Image formats"), it is possible to build Image.{bz2,lz4,lzma,lzo}
AArch64 images. However, the commit missed adding support for removing
those images on 'make ARCH=arm64 (dist)clean'.

Fix this by adding them to the target list.
Make sure to match the order of the recipes in the makefile.

Cc: stable@vger.kernel.org # v4.3+
Fixes: 0723c05fb75e44 ("arm64: enable more compressed Image formats")
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will@kernel.org>

arm64: localise Image objcopy flags

We currently define OBJCOPYFLAGS in the top-level arm64 Makefile, and
thus these flags will be passed to all uses of objcopy, kernel-wide, for
which they are not explicitly overridden. The flags we set are intended
for converting vmlinux (and ELF) into Image (a raw binary), and thus the
flags chosen are problematic for some other uses which do not expect a
raw binary result, e.g. the upcoming lkdtm rodata test:

http://www.openwall.com/lists/kernel-hardening/2016/06/08/2

This patch localises the objcopy flags such that they are only used for
the vmlinux -> Image conversion.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: kbuild: make "make install" not depend on vmlinux

For the same reason as commit 19514fc665ff ("arm, kbuild: make "make
install" not depend on vmlinux"), the install targets should never
trigger the rebuild of the kernel.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arm64: enable more compressed Image formats

Plumb up Makefile arguments for the already supported formats in the kbuild
system: lz4, bzip2, lzma, and lzo.

Note that just as with Image.gz, these images are not self-decompressing and
the booting firmware still needs to handle decompression before launching the
kernel image.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arm64: use new common dtc rule

The current rules have the .dtb files build in a different directory
from the .dts files. This patch changes arm64 to use the generic dtb
rule which builds .dtb files in the same directory as the source .dts.

This requires moving parts of arch/arm64/boot/Makefile into newly created
arch/arm64/boot/dts/Makefile, and updating arch/arm64/Makefile to call the
new Makefile.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>

arm64: Build infrastructure

This patch adds Makefile and Kconfig files required for building an
AArch64 kernel.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>