kbuild: Quote OBJCOPY var to avoid a pahole call break the build

The ccache tool can be used to speed up cross-compilation, by calling the
compiler and binutils through ccache. For example, followin

kbuild: Quote OBJCOPY var to avoid a pahole call break the build

The ccache tool can be used to speed up cross-compilation, by calling the
compiler and binutils through ccache. For example, following should work:

$ export ARCH=arm64 CROSS_COMPILE="ccache aarch64-linux-gnu-"

$ make M=drivers/gpu/drm/rockchip/

but pahole fails to extract the BTF info from DWARF, breaking the build:

CC [M] drivers/gpu/drm/rockchip//rockchipdrm.mod.o
LD [M] drivers/gpu/drm/rockchip//rockchipdrm.ko
BTF [M] drivers/gpu/drm/rockchip//rockchipdrm.ko
aarch64-linux-gnu-objcopy: invalid option -- 'J'
Usage: aarch64-linux-gnu-objcopy [option(s)] in-file [out-file]
Copies a binary file, possibly transforming it in the process
...
make[1]: *** [scripts/Makefile.modpost:156: __modpost] Error 2
make: *** [Makefile:1866: modules] Error 2

this fails because OBJCOPY is set to "ccache aarch64-linux-gnu-copy" and
later pahole is executed with the following command line:

LLVM_OBJCOPY=$(OBJCOPY) $(PAHOLE) -J --btf_base vmlinux $@

which gets expanded to:

LLVM_OBJCOPY=ccache aarch64-linux-gnu-objcopy pahole -J ...

instead of:

LLVM_OBJCOPY="ccache aarch64-linux-gnu-objcopy" pahole -J ...

Fixes: 5f9ae91f7c0d ("kbuild: Build kernel module BTFs if BTF is enabled and pahole supports it")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/bpf/20210526215228.3729875-1-javierm@redhat.com

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kbuild: remove libelf checks from top Makefile

I do not see a good reason why only the libelf development package must
be so carefully checked.

Kbuild generally does not check host tools or librari

kbuild: remove libelf checks from top Makefile

I do not see a good reason why only the libelf development package must
be so carefully checked.

Kbuild generally does not check host tools or libraries.

For example, x86_64 defconfig fails to build with no libssl development
package installed.

scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory
21 | #include <openssl/bio.h>
| ^~~~~~~~~~~~~~~

To solve the build error, you need to install libssl-dev or openssl-devel
package, depending on your distribution.

'apt-file search', 'dnf provides', etc. is your frined to find a proper
package to install.

This commit removes all the libelf checks from the top Makefile.

If libelf is missing, objtool will fail to build in a similar pattern:

.../linux/tools/objtool/include/objtool/elf.h:10:10: fatal error: gelf.h: No such file or directory
10 | #include <gelf.h>

You need to install libelf-dev, libelf-devel, or elfutils-libelf-devel
to proceed.

Another remarkable change is, CONFIG_STACK_VALIDATION (without
CONFIG_UNWINDER_ORC) previously continued to build with a warning,
but now it will treat missing libelf as an error.

This is just a one-time installation, so it should not hurt to break
a build and make a user install the package.

BTW, the traditional way to handle such checks is autotool, but according
to [1], I do not expect the kernel build would have similar scripting
like './configure' does.

[1]: https://lore.kernel.org/lkml/CA+55aFzr2HTZVOuzpHYDwmtRJLsVzE-yqg2DHpHi_9ePsYp5ug@mail.gmail.com/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>

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Merge tag 'v5.13-rc2' into spi-5.13

Linux 5.13-rc2

Merge branch 'fixes-rc1' into fixes

Merge drm/drm-next into drm-intel-next

Time to get back in sync...

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-misc-next

Backmerging to get v5.12 fixes. Requested for vmwgfx.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-fixes into drm-misc-fixes

Start this new release drm-misc-fixes branch

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge branch 'next' into for-linus

Prepare input updates for 5.13 merge window.

Merge branch 'for-5.13/surface-system-aggregator-intergration' into for-linus

- Surface Aggregator Module support from Maximilian Luz

Merge tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull CFI on arm64 support from Kees Cook:
"This builds on last cycle's LTO work, and allows the arm64 kernels t

Merge tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull CFI on arm64 support from Kees Cook:
"This builds on last cycle's LTO work, and allows the arm64 kernels to
be built with Clang's Control Flow Integrity feature. This feature has
happily lived in Android kernels for almost 3 years[1], so I'm excited
to have it ready for upstream.

The wide diffstat is mainly due to the treewide fixing of mismatched
list_sort prototypes. Other things in core kernel are to address
various CFI corner cases. The largest code portion is the CFI runtime
implementation itself (which will be shared by all architectures
implementing support for CFI). The arm64 pieces are Acked by arm64
maintainers rather than coming through the arm64 tree since carrying
this tree over there was going to be awkward.

CFI support for x86 is still under development, but is pretty close.
There are a handful of corner cases on x86 that need some improvements
to Clang and objtool, but otherwise works well.

Summary:

- Clean up list_sort prototypes (Sami Tolvanen)

- Introduce CONFIG_CFI_CLANG for arm64 (Sami Tolvanen)"

* tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
arm64: allow CONFIG_CFI_CLANG to be selected
KVM: arm64: Disable CFI for nVHE
arm64: ftrace: use function_nocfi for ftrace_call
arm64: add __nocfi to __apply_alternatives
arm64: add __nocfi to functions that jump to a physical address
arm64: use function_nocfi with __pa_symbol
arm64: implement function_nocfi
psci: use function_nocfi for cpu_resume
lkdtm: use function_nocfi
treewide: Change list_sort to use const pointers
bpf: disable CFI in dispatcher functions
kallsyms: strip ThinLTO hashes from static functions
kthread: use WARN_ON_FUNCTION_MISMATCH
workqueue: use WARN_ON_FUNCTION_MISMATCH
module: ensure __cfi_check alignment
mm: add generic function_nocfi macro
cfi: add __cficanonical
add support for Clang CFI

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Merge tag 'v5.12-rc7' into ecryptfs/next

Required to pick up idmapped mount changes which changed some function
parameters.

add support for Clang CFI

This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect fu

add support for Clang CFI

This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect function call to ensure
the target is a valid function with the correct static type. This
restricts possible call targets and makes it more difficult for
an attacker to exploit bugs that allow the modification of stored
function pointers. For more details, see:

https://clang.llvm.org/docs/ControlFlowIntegrity.html

Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain
visibility to possible call targets. Kernel modules are supported
with Clang’s cross-DSO CFI mode, which allows checking between
independently compiled components.

With CFI enabled, the compiler injects a __cfi_check() function into
the kernel and each module for validating local call targets. For
cross-module calls that cannot be validated locally, the compiler
calls the global __cfi_slowpath_diag() function, which determines
the target module and calls the correct __cfi_check() function. This
patch includes a slowpath implementation that uses __module_address()
to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a
shadow map that speeds up module look-ups by ~3x.

Clang implements indirect call checking using jump tables and
offers two methods of generating them. With canonical jump tables,
the compiler renames each address-taken function to <function>.cfi
and points the original symbol to a jump table entry, which passes
__cfi_check() validation. This isn’t compatible with stand-alone
assembly code, which the compiler doesn’t instrument, and would
result in indirect calls to assembly code to fail. Therefore, we
default to using non-canonical jump tables instead, where the compiler
generates a local jump table entry <function>.cfi_jt for each
address-taken function, and replaces all references to the function
with the address of the jump table entry.

Note that because non-canonical jump table addresses are local
to each component, they break cross-module function address
equality. Specifically, the address of a global function will be
different in each module, as it's replaced with the address of a local
jump table entry. If this address is passed to a different module,
it won’t match the address of the same function taken there. This
may break code that relies on comparing addresses passed from other
components.

CFI checking can be disabled in a function with the __nocfi attribute.
Additionally, CFI can be disabled for an entire compilation unit by
filtering out CC_FLAGS_CFI.

By default, CFI failures result in a kernel panic to stop a potential
exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the
kernel prints out a rate-limited warning instead, and allows execution
to continue. This option is helpful for locating type mismatches, but
should only be enabled during development.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-2-samitolvanen@google.com

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Merge tag 'platform-drivers-x86-surface-aggregator-v5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 into for-5.13/surface-system-aggregator-intergration

Pull immu

Merge tag 'platform-drivers-x86-surface-aggregator-v5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 into for-5.13/surface-system-aggregator-intergration

Pull immutable integration branch from Hans de Goede to have a stable base for
SSAM (Surface System Aggregator Module) HID transport subsystem merge.

=====
Signed tag for the immutable platform-surface-aggregator-registry
branch for merging into other sub-systems.

Note this is based on v5.12-rc2.
=====

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Merge tag 'v5.12-rc4' into next

Sync up with the mainline to bring in newest APIs.

Merge drm/drm-next into drm-misc-next

Noralf needs some patches in 5.12-rc3, and we've been delaying the 5.12
merge due to the swap issue so it looks like a good time.

Signed-off-by: Maxime Ripard

Merge drm/drm-next into drm-misc-next

Noralf needs some patches in 5.12-rc3, and we've been delaying the 5.12
merge due to the swap issue so it looks like a good time.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

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Merge tag 'irqchip-fixes-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

- More compatible strings for the Ingenic

Merge tag 'irqchip-fixes-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

- More compatible strings for the Ingenic irqchip (introducing the
JZ4760B SoC)
- Select GENERIC_IRQ_MULTI_HANDLER on the ARM ep93xx platform
- Drop all GENERIC_IRQ_MULTI_HANDLER selections from the irqchip
Kconfig, now relying on the architecture to get it right
- Drop the debugfs_file field from struct irq_domain, now that
debugfs can track things on its own

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Merge drm/drm-next into drm-intel-next

Sync up with upstream.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge remote-tracking branch 'torvalds/master' into perf/core

To pick up the fixes sent for v5.12 and continue development based on
v5.12-rc2, i.e. without the swap on file bug.

This also gets a sl

Merge remote-tracking branch 'torvalds/master' into perf/core

To pick up the fixes sent for v5.12 and continue development based on
v5.12-rc2, i.e. without the swap on file bug.

This also gets a slightly newer and better tools/perf/arch/arm/util/cs-etm.c
patch version, using the BIT() macro, that had already been slated to
v5.13 but ended up going to v5.12-rc1 on an older version.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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Merge branch 'fixes-rc2' into fixes

Merge tag 'tags/sound-sdw-kconfig-fixes' into for-linus

ALSA/ASoC/SOF/SoundWire: fix Kconfig issues

In January, Intel kbuild bot and Arnd Bergmann reported multiple
issues with randconfig. This pat

Merge tag 'tags/sound-sdw-kconfig-fixes' into for-linus

ALSA/ASoC/SOF/SoundWire: fix Kconfig issues

In January, Intel kbuild bot and Arnd Bergmann reported multiple
issues with randconfig. This patchset builds on Arnd's suggestions to

a) expose ACPI and PCI devices in separate modules, while sof-acpi-dev
and sof-pci-dev become helpers. This will result in minor changes
required for developers/testers, i.e. modprobe snd-sof-pci will no
longer result in a probe. The SOF CI was already updated to deal with
this module dependency change and introduction of new modules.

b) Fix SOF/SoundWire/DSP_config dependencies by moving the code
required to detect SoundWire presence in ACPI tables to sound/hda.

Link: https://lore.kernel.org/r/20210302003125.1178419-1-pierre-louis.bossart@linux.intel.com

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Merge remote-tracking branch 'net/master'

Merge tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull more clang LTO updates from Kees Cook:
"Clang LTO x86 enablement.

Full disclosure: while th

Merge tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull more clang LTO updates from Kees Cook:
"Clang LTO x86 enablement.

Full disclosure: while this has _not_ been in linux-next (since it
initially looked like the objtool dependencies weren't going to make
v5.12), it has been under daily build and runtime testing by Sami for
quite some time. These x86 portions have been discussed on lkml, with
Peter, Josh, and others helping nail things down.

The bulk of the changes are to get objtool working happily. The rest
of the x86 enablement is very small.

Summary:

- Generate __mcount_loc in objtool (Peter Zijlstra)

- Support running objtool against vmlinux.o (Sami Tolvanen)

- Clang LTO enablement for x86 (Sami Tolvanen)"

Link: https://lore.kernel.org/lkml/20201013003203.4168817-26-samitolvanen@google.com/
Link: https://lore.kernel.org/lkml/cover.1611263461.git.jpoimboe@redhat.com/

* tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: lto: force rebuilds when switching CONFIG_LTO
x86, build: allow LTO to be selected
x86, cpu: disable LTO for cpu.c
x86, vdso: disable LTO only for vDSO
kbuild: lto: postpone objtool
objtool: Split noinstr validation from --vmlinux
x86, build: use objtool mcount
tracing: add support for objtool mcount
objtool: Don't autodetect vmlinux.o
objtool: Fix __mcount_loc generation with Clang's assembler
objtool: Add a pass for generating __mcount_loc

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kbuild: lto: postpone objtool

With LTO, LLVM bitcode won't be compiled into native code until
modpost_link, or modfinal for modules. This change postpones calls
to objtool until after these steps, a

kbuild: lto: postpone objtool

With LTO, LLVM bitcode won't be compiled into native code until
modpost_link, or modfinal for modules. This change postpones calls
to objtool until after these steps, and moves objtool_args to
Makefile.lib, so the arguments can be reused in Makefile.modfinal.

As we didn't have objects to process earlier, we use --duplicate
when processing vmlinux.o. This change also disables unreachable
instruction warnings with LTO to avoid warnings about the int3
padding between functions.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>

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Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang LTO updates from Kees Cook:
"Clang Link Time Optimization.

This is built on the work done p

Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang LTO updates from Kees Cook:
"Clang Link Time Optimization.

This is built on the work done preparing for LTO by arm64 folks,
tracing folks, etc. This includes the core changes as well as the
remaining pieces for arm64 (LTO has been the default build method on
Android for about 3 years now, as it is the prerequisite for the
Control Flow Integrity protections).

While x86 LTO enablement is done, it depends on some pending objtool
clean-ups. It's possible that I'll send a "part 2" pull request for
LTO that includes x86 support.

For merge log posterity, and as detailed in commit dc5723b02e52
("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO
build:

make LLVM=1 LLVM_IAS=1 defconfig
scripts/config -e LTO_CLANG_THIN
make LLVM=1 LLVM_IAS=1

(To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-"
and "ARCH=arm64" to the "make" command lines.)

Summary:

- Clang LTO build infrastructure and arm64-specific enablement (Sami
Tolvanen)

- Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)"

* tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
arm64: allow LTO to be selected
arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS
arm64: vdso: disable LTO
drivers/misc/lkdtm: disable LTO for rodata.o
efi/libstub: disable LTO
scripts/mod: disable LTO for empty.c
modpost: lto: strip .lto from module names
PCI: Fix PREL32 relocations for LTO
init: lto: fix PREL32 relocations
init: lto: ensure initcall ordering
kbuild: lto: add a default list of used symbols
kbuild: lto: merge module sections
kbuild: lto: limit inlining
kbuild: lto: fix module versioning
kbuild: add support for Clang LTO
tracing: move function tracer options to Kconfig

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Merge branch 'next' into for-linus

Prepare input updates for 5.12 merge window.