Linux 6.9-rc4

Linux 6.9-rc3

Linux 6.9-rc2

Linux 6.9-rc1

kbuild: unexport abs_srctree and abs_objtree

Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory")
exported abs_srctree and abs_objtree to avoid recomputation after the
sub-make. However, this approach turned out to be fragile.

Commit 5fa94ceb793e ("kbuild: set correct abs_srctree and abs_objtree
for package builds") moved them above "ifneq ($(sub_make_done),1)",
eliminating the need for exporting them.

These are only needed in the top Makefile. If an absolute path is
required in sub-directories, you can use $(abspath ) or $(realpath )
as needed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: fix inconsistent indentation in top Makefile

Commit 3b9ab248bc45 ("kbuild: use 4-space indentation when followed
by conditionals") introduced inconsistent indentation because it
deliberately touched only the conditional directives to minimize the
change set.

This commit reformats some blocks in the top Makefile so they are
consistently indented with 4 spaces.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

kbuild: Use -fmin-function-alignment when available

GCC recently added option -fmin-function-alignment, which should appear
in GCC 14. Unlike -falign-functions, this option causes all functions to
be aligned at the specified value, including the cold ones.

In particular, when an arm64 kernel is built with
DYNAMIC_FTRACE_WITH_CALL_OPS=y, the 8-byte function alignment is
required for correct functionality. This was done by -falign-functions=8
and having workarounds in the kernel to force the compiler to follow
this alignment. The new -fmin-function-alignment option directly
guarantees it.

Detect availability of -fmin-function-alignment and use it instead of
-falign-functions when present. Introduce CC_HAS_SANE_FUNCTION_ALIGNMENT
and enable __cold to work as expected when it is set.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: simplify dtbs_install by reading the list of compiled DTBs

Retrieve the list of *.dtb(o) files from arch/*/boot/dts/dtbs-list
instead of traversing the directory tree again.

Please note that 'make dtbs_install' installs *.dtb(o) files directly
added to dtb-y because scripts/Makefile.dtbinst installs $(dtb-y)
without expanding the -dtbs suffix.

This commit preserves this behavior.

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

kbuild: create a list of all built DTB files

It is useful to have a list of all *.dtb and *.dtbo files generated
from the current build.

With this commit, 'make dtbs' creates arch/*/boot/dts/dtbs-list, which
lists the dtb(o) files created in the current build. It maintains the
order of the dtb-y additions in Makefiles although the order is not
important for DTBs. It is a (good) side effect through the reuse of the
modules.order rule.

Please note this list only includes the files directly added to dtb-y.

For example, consider this case:

foo-dtbs := foo_base.dtb foo_overlay.dtbo
dtb-y := foo.dtb

In this example, the list will include foo.dtb, but not foo_base.dtb
or foo_overlay.dtbo.

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

Makefile: drop warn-stack-size plugin opt

Now that the minimum supported version of LLVM for building the kernel has
been bumped to 13.0.1, the inner ifeq statement is always false, as the
build will fail during the configuration stage for older LLVM versions.

This effectively reverts commit 24845dcb170e ("Makefile: LTO: have linker
check -Wframe-larger-than") and its follow up fix, commit 0236526d76b8
("Makefile: lto: Pass -warn-stack-size only on LLD < 13.0.0").

Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-2-f5ff9bda41c5@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Conor Dooley <conor@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

rust: Refactor the build target to allow the use of builtin targets

Eventually we want all architectures to be using the target as defined
by rustc. However currently some architectures can't do that and are
using the target.json specification. This puts in place the foundation
to allow the use of the builtin target definition or a target.json
specification.

Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231020155056.3495121-2-Jamie.Cunliffe@arm.com
[catalin.marinas@arm.com: squashed loongarch ifneq fix from WANG Rui]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kbuild: mark `rustc` (and others) invocations as recursive

`rustc` (like Cargo) may take advantage of the jobserver at any time
(e.g. for backend parallelism, or eventually frontend too). In the kernel,
we call `rustc` with `-Ccodegen-units=1` (and `-Zthreads` is 1 so far),
so we do not expect parallelism. However, in the upcoming Rust 1.76.0, a
warning is emitted by `rustc` [1] when it cannot connect to the jobserver
it was passed (in many cases, but not all: compiling and `--print sysroot`
do, but `--version` does not). And given GNU Make always passes
the jobserver in the environment variable (even when a line is deemed
non-recursive), `rustc` will end up complaining about it (in particular
in Make 4.3 where there is only the simple pipe jobserver style).

One solution is to remove the jobserver from `MAKEFLAGS`. However, we
can mark the lines with calls to `rustc` (and Cargo) as recursive, which
looks simpler. This is being documented as a recommendation in `rustc`
[2] and allows us to be ready for the time we may use parallelism inside
`rustc` (potentially now, if a user passes `-Zthreads`). Thus do so.

Similarly, do the same for `rustdoc` and `cargo` calls.

Finally, there is one case that the solution does not cover, which is the
`$(shell ...)` call we have. Thus, for that one, set an empty `MAKEFLAGS`
environment variable.

Link: https://github.com/rust-lang/rust/issues/120515 [1]
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://github.com/rust-lang/rust/pull/121564 [2]
Link: https://lore.kernel.org/r/20240217002638.57373-1-ojeda@kernel.org
[ Reworded to add link to PR documenting the recommendation. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Linux 6.8

Linux 6.8-rc7

Linux 6.8-rc6

Linux 6.8-rc5

kbuild: use 4-space indentation when followed by conditionals

GNU Make manual [1] clearly forbids a tab at the beginning of the
conditional directive line:
"Extra spaces are allowed and ignored at the beginning of the
conditional directive line, but a tab is not allowed."

This will not work for the next release of GNU Make, hence commit
82175d1f9430 ("kbuild: Replace tabs with spaces when followed by
conditionals") replaced the inappropriate tabs with 8 spaces.

However, the 8-space indentation cannot be visually distinguished.
Linus suggested 2-4 spaces for those nested if-statements. [2]

This commit redoes the replacement with 4 spaces.

[1]: https://www.gnu.org/software/make/manual/make.html#Conditional-Syntax
[2]: https://lore.kernel.org/all/CAHk-=whJKZNZWsa-VNDKafS_VfY4a5dAjG-r8BZgWk_a-xSepw@mail.gmail.com/

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Linux 6.8-rc4

Linux 6.8-rc3

kbuild: Replace tabs with spaces when followed by conditionals

This is needed for the future (post make-4.4.1) versions of gnu make.

Starting from https://git.savannah.gnu.org/cgit/make.git/commit/?id=07fcee35f058a876447c8a021f9eb1943f902534
gnu make won't allow conditionals to follow recipe prefix.

For example there is a tab followed by ifeq on line 324 in the root Makefile.
With the new make this conditional causes the following

$ make cpu.o
/home/dgoncharov/src/linux-kbuild/Makefile:2063: *** missing 'endif'. Stop.
make: *** [Makefile:240: __sub-make] Error 2

This patch replaces tabs followed by conditionals with 8 spaces.

See https://savannah.gnu.org/bugs/?64185 and
https://savannah.gnu.org/bugs/?64259 for details.

Signed-off-by: Dmitry Goncharov <dgoncharov@users.sf.net>
Reported-by: Martin Dorey <martin.dorey@hitachivantara.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: fix W= flags in the help message

W=c and W=e are supported.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Linux 6.8-rc2

init: Kconfig: Disable -Wstringop-overflow for GCC-11

-Wstringop-overflow is buggy in GCC-11. Therefore, we should disable
this option specifically for that compiler version. To achieve this,
we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW.

The compiler option related to string operation overflow is now managed
under configuration CC_STRINGOP_OVERFLOW. This option is enabled by
default for all other versions of GCC that support it.

Link: https://lore.kernel.org/lkml/b3c99290-40bc-426f-b3d2-1aa903f95c4e@embeddedor.com/
Link: https://lore.kernel.org/lkml/20231128091351.2bfb38dd@canb.auug.org.au/
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/linux-hardening/ZWj1+jkweEDWbmAR@work/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Makefile: Enable -Wstringop-overflow globally

It seems that we have finished addressing all the remaining
issues regarding -Wstringop-overflow. So, we are now in good
shape to enable this compiler option globally.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Linux 6.8-rc1

kbuild: resolve symlinks for O= properly

Currently, Kbuild follows the logical chain of directories for the O=
option, just like 'cd' (or 'realpath --logical') does.

Example:

$ mkdir -p /tmp/a /tmp/x/y
$ ln -s /tmp/x/y /tmp/a/b
$ realpath /tmp/a/b/..
/tmp/x
$ realpath --logical /tmp/a/b/..
/tmp/a
$ make O=/tmp/a/b/.. defconfig
make[1]: Entering directory '/tmp/a'
[snip]
make[1]: Leaving directory '/tmp/a'

'make O=/tmp/a/b/.. defconfig' creates the kernel configuration in
/tmp/a instead of /tmp/x despite /tmp/a/b/.. resolves to /tmp/x.

This is because Kbuild internally uses the 'cd ... && pwd' for the
path resolution, but this behavior is not predictable for users.
Additionally, it is not consistent with how the Kbuild handles the
M= option or GNU Make works with 'make -C /tmp/a/b/..'.

Using the physical directory structure for the O= option seems more
reasonable.

The comment says "expand a shell special character '~'", but it has
already been expanded to the home directory in the command line.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

kbuild: support W=c and W=e shorthands for Kconfig

KCONFIG_WARN_UNKNOWN_SYMBOLS=1 and KCONFIG_WERROR=1 are descriptive
and suitable in scripting, but typing them from the command line can
be tedious.

Associate them with KBUILD_EXTRA_WARN (and the W= shorthand).

Support a new letter 'c' to enable extra checks in Kconfig. You can
still manage compiler warnings (W=1) and Kconfig warnings (W=c)
independently.

Reuse the letter 'e' to turn Kconfig warnings into errors.

As usual, you can combine multiple letters in KCONFIG_EXTRA_WARN.

$ KCONFIG_WARN_UNKNOWN_SYMBOLS=1 KCONFIG_WERROR=1 make defconfig

can be shortened to:

$ KBUILD_EXTRA_WARN=ce make defconfig

or, even shorter:

$ make W=ce defconfig

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

kbuild: remove the last use of old cmd_src_tar rule in packaging

The rpm-pkg and deb-pkg targets have transitioned to using 'git archive'
for tarball creation.

Although the old cmd_src_tar is still used by snap-pkg, there is no need
to pack and unpack a tarball solely for passing the source to snapcraft.

Instead, you can use 'source-type: local' to tell the source location to
snapcraft.

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

checkstack: allow to pass MINSTACKSIZE parameter

The checkstack script omits all functions with a stack usage of less than
100 bytes. However the script already has support for a parameter which
allows to override the default, but it cannot be set with

$ make checkstack

Add a MINSTACKSIZE parameter which allows to change the default. This might
be useful in order to print the stack usage of all functions, or only those
with large stack usage:

$ make checkstack MINSTACKSIZE=0
$ make checkstack MINSTACKSIZE=800

Link: https://lkml.kernel.org/r/20231120183719.2188479-4-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Maninder Singh <maninder1.s@samsung.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Linux 6.7

Linux 6.7-rc8

Linux 6.7-rc7

Linux 6.7-rc6

Linux 6.7-rc5

Linux 6.7-rc4

Linux 6.7-rc3

Linux 6.7-rc2

Linux 6.7-rc1

kbuild: Correct missing architecture-specific hyphens

These should add a hyphen to indicate that it makes a adjective. Fix
them.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: avoid too many execution of scripts/pahole-flags.sh

scripts/pahole-flags.sh is executed so many times.

You can confirm it, as follows:

$ cat <<EOF >> scripts/pahole-flags.sh
> echo "scripts/pahole-flags.sh was executed" >&2
> EOF

$ make -s
scripts/pahole-flags.sh was executed
scripts/pahole-flags.sh was executed
scripts/pahole-flags.sh was executed
scripts/pahole-flags.sh was executed
scripts/pahole-flags.sh was executed
[ lots of repeated lines... ]

This scripts is executed more than 20 times during the kernel build
because PAHOLE_FLAGS is a recursively expanded variable and exported
to sub-processes.

With GNU Make >= 4.4, it is executed more than 60 times because
exported variables are also passed to other $(shell ) invocations.
Without careful coding, it is known to cause an exponential fork
explosion. [1]

The use of $(shell ) in an exported recursive variable is likely wrong
because $(shell ) is always evaluated due to the 'export' keyword, and
the evaluation can occur multiple times by the nature of recursive
variables.

Convert the shell script to a Makefile, which is included only when
CONFIG_DEBUG_INFO_BTF=y.

[1]: https://savannah.gnu.org/bugs/index.php?64746

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>

kbuild: unify no-compiler-targets and no-sync-config-targets

Now that vdso_install does not depend on any in-tree build artifact,
it no longer needs a compiler, making no-compiler-targets the same
as no-sync-config-targets.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: unify vdso_install rules

Currently, there is no standard implementation for vdso_install,
leading to various issues:

1. Code duplication

Many architectures duplicate similar code just for copying files
to the install destination.

Some architectures (arm, sparc, x86) create build-id symlinks,
introducing more code duplication.

2. Unintended updates of in-tree build artifacts

The vdso_install rule depends on the vdso files to install.
It may update in-tree build artifacts. This can be problematic,
as explained in commit 19514fc665ff ("arm, kbuild: make
"make install" not depend on vmlinux").

3. Broken code in some architectures

Makefile code is often copied from one architecture to another
without proper adaptation.

'make vdso_install' for parisc does not work.

'make vdso_install' for s390 installs vdso64, but not vdso32.

To address these problems, this commit introduces a generic vdso_install
rule.

Architectures that support vdso_install need to define vdso-install-y
in arch/*/Makefile. vdso-install-y lists the files to install.

For example, arch/x86/Makefile looks like this:

vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg
vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg
vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg
vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg

These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix,
if exists, stripped away.

vdso-install-y can optionally take the second field after the colon
separator. This is needed because some architectures install a vdso
file as a different base name.

The following is a snippet from arch/arm64/Makefile.

vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so

This will rename vdso.so.dbg to vdso32.so during installation. If such
architectures change their implementation so that the base names match,
this workaround will go away.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Guo Ren <guoren@kernel.org>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

kbuild: rpm-pkg: generate kernel.spec in rpmbuild/SPECS/

kernel.spec is the last piece that resides outside the rpmbuild/
directory. Move all the RPM-related files to rpmbuild/ consistently.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>

kbuild: Merge per-arch config for kselftest-merge target

Some kselftests has a per-arch config,
e.g. tools/testing/selftests/bpf/config.s390x.

Make sure these configs are picked up by the kselftest-merge target.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kbuild: Let builtin have precedence over modules for kselftest-merge

The kselftest-merge target walks all kselftests configs, and merges
them. However, builtin does not have precedence over modules. This
breaks some of the tests, e.g.:

$ grep CONFIG_NF_NAT tools/testing/selftests/{bpf,net}/config
tools/testing/selftests/bpf/config:CONFIG_NF_NAT=y
tools/testing/selftests/net/config:CONFIG_NF_NAT=m

Here, the net config will set NF_NAT to module, which makes it clunky
to run the BPF tests.

Add '-y' to scripts/kconfig/merge_config.sh.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Documentation: Drop or replace remaining mentions of IA64

Drop or update mentions of IA64, as appropriate.

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

Linux 6.6

Linux 6.6-rc7

kbuild: remove old Rust docs output path

The Rust code documentation output path moved from `rust/doc` to
`Documentation/output/rust/rustdoc`. The `make cleandocs` target
takes care of cleaning it now since it is integrated with the rest
of the documentation.

Thus remove the old reference.

Fixes: 48fadf440075 ("docs: Move rustdoc output, cross-reference it")
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20231018160145.1017340-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Linux 6.6-rc6

Linux 6.6-rc5

Linux 6.6-rc4

Linux 6.6-rc3

Linux 6.6-rc2

Linux 6.6-rc1

kbuild: Show marked Kconfig fragments in "help"

Currently the Kconfig fragments in kernel/configs and arch/*/configs
that aren't used internally aren't discoverable through "make help",
which consists of hard-coded lists of config fragments. Instead, list
all the fragment targets that have a "# Help: " comment prefix so the
targets can be generated dynamically.

Add logic to the Makefile to search for and display the fragment and
comment. Add comments to fragments that are intended to be direct targets.

Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: support modules_sign for external modules as well

The modules_sign target is currently only available for in-tree modules,
but it actually works for external modules as well.

Move the modules_sign rule to the common part.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: move more module installation code to scripts/Makefile.modinst

Move more relevant code to scripts/Makefile.modinst.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: remove $(MODLIB)/source symlink

This reverts the old commit "kbuild: Introduce source symlink in
/lib/modules/.../". [1]

The current Kbuild does not require $(MODLIB)/source. If the kernel was
built in a separate output directory, $(MODLIB)/build/Makefile wraps
the Makefile in the source tree. It is enough for building external
modules.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=e09e58867154b8aae0a3ac26a9b1c05962f5a355

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: move depmod rule to scripts/Makefile.modinst

depmod is a part of the module installation.

scripts/Makefile.modinst is a better place to run it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: add modules_sign to no-{compiler,sync-config}-targets

Like modules_install, modules_sign should avoid the syncconfig.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: do not run depmod for 'make modules_sign'

Commit 961ab4a3cd66 ("kbuild: merge scripts/Makefile.modsign to
scripts/Makefile.modinst") started to run depmod at the end of
'make modules_sign'.

Move the depmod rule to scripts/Makefile.modinst and run it only when
$(modules_sign_only) is empty.

Fixes: 961ab4a3cd66 ("kbuild: merge scripts/Makefile.modsign to scripts/Makefile.modinst")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: remove include/ksym from CLEAN_FILES

This is a remnant of commit 5e9e95cc9148 ("kbuild: implement
CONFIG_TRIM_UNUSED_KSYMS without recursion").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

kbuild: consolidate warning flags in scripts/Makefile.extrawarn

Warning options are enabled and disabled in inconsistent ways and
inconsistent locations. Start rearranging those by moving all options
into Makefile.extrawarn.

This should not change any behavior, but makes sure we can group them
in a way that ensures that each warning that got temporarily disabled
is turned back on at an appropriate W=1 level later on.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: rpm-pkg: rename binkernel.spec to kernel.spec

Now kernel.spec and binkernel.spec have the exactly same contents.

Use kernel.spec for binrpm-pkg as well.

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

kbuild: add a phony target to run a command with Kbuild env vars

There are some cases where we want to run a command with the same
environment variables as Kbuild uses. For example, 'make coccicheck'
invokes scripts/coccicheck from the top Makefile so that the script can
reference to ${LINUXINCLUDE}, ${KBUILD_EXTMOD}, etc. The top Makefile
defines several phony targets that run a script.

We do it also for an internally used script, which results in a somewhat
complex call graph.

One example:

debian/rules binary-arch
-> make intdeb-pkg
-> scripts/package/builddeb

It is also tedious to add a dedicated target like 'intdeb-pkg' for each
use case.

Add a generic target 'run-command' to run an arbitrary command in an
environment with all Kbuild variables set.

The usage is:

$ make run-command KBUILD_RUN_COMMAND=<command>

The concept is similar to:

$ dpkg-architecture -c <command>

This executes <command> in an environment which has all DEB_* variables
defined.

Convert the existing 'make intdeb-pkg'.

Another possible usage is to interrogate a Make variable.

$ make run-command KBUILD_RUN_COMMAND='echo $(KBUILD_CFLAGS)'

might be useful to see KBUILD_CFLAGS set by the top Makefile.

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

kbuild: Enable -Wenum-conversion by default

This diagnostic checks whether there is a type mismatch when
converting enums (assign an enum of type A to an enum of type B, for
example) and it caught a legit issue recently. The reason it didn't show
is because that warning is enabled only with -Wextra with GCC. Clang,
however, enables it by default.

GCC folks were considering enabling it by default but it was too noisy
back then:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78736

Now that due to clang all those warnings have been fixed, enable it with
GCC too.

allmodconfig tests done with: x86, arm{,64}, powerpc{,64}, riscv
crossbuilds.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

rust: enable `no_mangle_with_rust_abi` Clippy lint

Introduced in Rust 1.69.0 [1], this lint prevents forgetting to set
the C ABI when using `#[no_mangle]` (or thinking it is implied).

For instance, it would have prevented the issue [2] fixed by commit
c682e4c37d2b ("rust: kernel: Mark rust_fmt_argument as extern "C"").

error: `#[no_mangle]` set on a function with the default (`Rust`) ABI
--> rust/kernel/print.rs:21:1
|
21 | / unsafe fn rust_fmt_argument(
22 | | buf: *mut c_char,
23 | | end: *mut c_char,
24 | | ptr: *const c_void,
25 | | ) -> *mut c_char {
| |________________^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#no_mangle_with_rust_abi
= note: requested on the command line with `-D clippy::no-mangle-with-rust-abi`
help: set an ABI
|
21 | unsafe extern "C" fn rust_fmt_argument(
| ++++++++++
help: or explicitly set the default
|
21 | unsafe extern "Rust" fn rust_fmt_argument(
| +++++++++++++

Thus enable it.

In rare cases, we may need to use the Rust ABI even with `#[no_mangle]`
(e.g. one case, before 1.71.0, would have been the `__rust_*`
functions). In those cases, we would need to `#[allow(...)]` the lint,
since using `extern "Rust"` explicitly (as the compiler suggests)
currently gets overwritten by `rustfmt` [3].

Link: https://github.com/rust-lang/rust-clippy/issues/10347 [1]
Link: https://github.com/Rust-for-Linux/linux/pull/967 [2]
Link: https://github.com/rust-lang/rustfmt/issues/5701 [3]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230729220317.416771-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

kbuild: rust_is_available: remove -v option

The -v option is passed when this script is invoked from Makefile,
but not when invoked from Kconfig.

As you can see in scripts/Kconfig.include, the 'success' macro suppresses
stdout and stderr anyway, so this script does not need to be quiet.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230109061436.3146442-1-masahiroy@kernel.org
[ Reworded prefix to match the others in the patch series. ]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230616001631.463536-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

scripts: `make rust-analyzer` for out-of-tree modules

Adds support for out-of-tree rust modules to use the `rust-analyzer`
make target to generate the rust-project.json file.

The change involves adding an optional parameter `external_src` to the
`generate_rust_analyzer.py` which expects the path to the out-of-tree
module's source directory. When this parameter is passed, I have chosen
not to add the non-core modules (samples and drivers) into the result
since these are not expected to be used in third party modules. Related
changes are also made to the Makefile and rust/Makefile allowing the
`rust-analyzer` target to be used for out-of-tree modules as well.

Link: https://github.com/Rust-for-Linux/linux/pull/914
Link: https://github.com/Rust-for-Linux/rust-out-of-tree-module/pull/2
Signed-off-by: Vinay Varma <varmavinaym@gmail.com>
Link: https://lore.kernel.org/r/20230411091714.130525-1-varmavinaym@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Linux 6.5

Linux 6.5-rc7

Linux 6.5-rc6

Linux 6.5-rc5

Linux 6.5-rc4

Linux 6.5-rc3

kbuild: flatten KBUILD_CFLAGS

Make it slightly easier to see which compiler options are added and
removed (and not worry about column limit too!).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Linux 6.5-rc2

Linux 6.5-rc1

kbuild: Drop -Wdeclaration-after-statement

With the advent on scope-based resource management it comes really
tedious to abide by the contraints of -Wdeclaration-after-statement.

It will still be recommeneded to place declarations at the start of a
scope where possible, but it will no longer be enforced.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/CAHk-%3Dwi-RyoUhbChiVaJZoZXheAwnJ7OO%3DGxe85BkPAd93TwDA%40mail.gmail.com

kbuild: revive "Entering directory" for Make >= 4.4.1

With commit 9da0763bdd82 ("kbuild: Use relative path when building in
a subdir of the source tree"), compiler messages in out-of-tree builds
include relative paths, which are relative to the build directory, not
the directory where make was started.

To help IDEs/editors find the source files, Kbuild lets GNU Make print
"Entering directory ..." when it changes the working directory. It has
been working fine for a long time, but David reported it is broken with
the latest GNU Make.

The behavior was changed by GNU Make commit 8f9e7722ff0f ("[SV 63537]
Fix setting -w in makefiles"). Previously, setting --no-print-directory
to MAKEFLAGS only affected child makes, but it is now interpreted in
the current make as soon as it is set.

[test code]

$ cat /tmp/Makefile
ifneq ($(SUBMAKE),1)
MAKEFLAGS += --no-print-directory
all: ; $(MAKE) SUBMAKE=1
else
all: ; :
endif

[before 8f9e7722ff0f]

$ make -C /tmp
make: Entering directory '/tmp'
make SUBMAKE=1
:
make: Leaving directory '/tmp'

[after 8f9e7722ff0f]

$ make -C /tmp
make SUBMAKE=1
:

Previously, the effect of --no-print-directory was delayed until Kbuild
started the directory descending, but it is no longer true with GNU Make
4.4.1.

This commit adds one more recursion to cater to GNU Make >= 4.4.1.

When Kbuild needs to change the working directory, __submake will be
executed twice.

__submake without --no-print-directory --> show "Entering directory ..."
__submake with --no-print-directory --> parse the rest of Makefile

We end up with one more recursion than needed for GNU Make < 4.4.1, but
I do not want to complicate the version check.

Reported-by: David Howells <dhowells@redhat.com>
Closes: https://lore.kernel.org/all/2427604.1686237298@warthog.procyon.org.uk/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <n.schier@avm.de>

kbuild: set correct abs_srctree and abs_objtree for package builds

When you run 'make rpm-pkg', the rpmbuild tool builds the kernel in
rpmbuild/BUILD, but $(abs_srctree) and $(abs_objtree) point to the
directory path where make was started, not the kernel is actually
being built. The same applies to 'make snap-pkg'. Fix it.

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

kbuild: make modules_install copy modules.builtin(.modinfo)

Josh Triplett reports that initramfs-tools needs modules.builtin and
modules.builtin.modinfo to create a working initramfs for a non-modular
kernel.

If this is a general tooling issue not limited to Debian, I think it
makes sense to change modules_install.

This commit changes the targets as follows when CONFIG_MODULES=n.

In-tree builds:
make modules -> no-op
make modules_install -> install modules.builtin(.modinfo)

External module builds:
make modules -> show error message like before
make modules_install -> show error message like before

Link: https://lore.kernel.org/lkml/36a4014c73a52af27d930d3ca31d362b60f4461c.1686356364.git.josh@joshtriplett.org/
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Josh Triplett <josh@joshtriplett.org>

kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion

When CONFIG_TRIM_UNUSED_KSYMS is enabled, Kbuild recursively traverses
the directory tree to determine which EXPORT_SYMBOL to trim. If an
EXPORT_SYMBOL turns out to be unused by anyone, Kbuild begins the
second traverse, where some source files are recompiled with their
EXPORT_SYMBOL() tuned into a no-op.

Linus stated negative opinions about this slowness in commits:

- 5cf0fd591f2e ("Kbuild: disable TRIM_UNUSED_KSYMS option")
- a555bdd0c58c ("Kbuild: enable TRIM_UNUSED_KSYMS again, with some guarding")

We can do this better now. The final data structures of EXPORT_SYMBOL
are generated by the modpost stage, so modpost can selectively emit
KSYMTAB entries that are really used by modules.

Commit f73edc8951b2 ("kbuild: unify two modpost invocations") is another
ground-work to do this in a one-pass algorithm. With the list of modules,
modpost sets sym->used if it is used by a module. modpost emits KSYMTAB
only for symbols with sym->used==true.

BTW, Nicolas explained why the trimming was implemented with recursion:

https://lore.kernel.org/all/2o2rpn97-79nq-p7s2-nq5-8p83391473r@syhkavp.arg/

Actually, we never achieved that level of optimization where the chain
reaction of trimming comes into play because:

- CONFIG_LTO_CLANG cannot remove any unused symbols
- CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is enabled only for vmlinux,
but not modules

If deeper trimming is required, we need to revisit this, but I guess
that is unlikely to happen.

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

Linux 6.4

Linux 6.4-rc7

Linux 6.4-rc6

Linux 6.4-rc5

Linux 6.4-rc4

kbuild: Enable -fstrict-flex-arrays=3

The -fstrict-flex-arrays=3 option is now available with the release
of GCC 13[1] and Clang 16[2]. This feature instructs the compiler to
treat only C99 flexible arrays as dynamically sized for the purposes of
object size calculations. In other words, the ancient practice of using
1-element arrays, or the GNU extension of using 0-sized arrays, as a
dynamically sized array is disabled. This allows CONFIG_UBSAN_BOUNDS,
CONFIG_FORTIFY_SOURCE, and other object-size aware features to behave
unambiguously in the face of trailing arrays: only C99 flexible arrays
are considered to be dynamically sized. For yet more detail, see:
https://people.kernel.org/kees/bounded-flexible-arrays-in-c

Enabling this will help track down any outstanding cases of fake
flexible arrays that need attention in kernel code.

[1] https://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html#index-fstrict-flex-arrays
[2] https://clang.llvm.org/docs/ClangCommandLineReference.html#cmdoption-clang-fstrict-flex-arrays

Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: linux-kbuild@vger.kernel.org
Co-developed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

Linux 6.4-rc3

Linux 6.4-rc2

Linux 6.4-rc1

Makefile: use -z pack-relative-relocs

Commit 27f2a4db76e8 ("Makefile: fix GDB warning with CONFIG_RELR")
added --use-android-relr-tags to fix a GDB warning

BFD: /android0/linux-next/vmlinux: unknown type [0x13] section `.relr.dyn'

The GDB warning has been fixed in version 11.2.

The DT_ANDROID_RELR tag was deprecated since DT_RELR was standardized.
Thus, --use-android-relr-tags should be removed. While making the
change, try -z pack-relative-relocs, which is supported since LLD 15.
Keep supporting --pack-dyn-relocs=relr as well for older LLD versions.
There is no indication of obsolescence for --pack-dyn-relocs=relr.

As of today, GNU ld supports the latter option for x86 and powerpc64
ports and has no intention to support --pack-dyn-relocs=relr. In the
absence of the glibc symbol version GLIBC_ABI_DT_RELR,
--pack-dyn-relocs=relr and -z pack-relative-relocs are identical in
ld.lld.

GNU ld and newer versions of LLD report warnings (instead of errors) for
unknown -z options. Only errors lead to non-zero exit codes. Therefore,
we should test --pack-dyn-relocs=relr before testing
-z pack-relative-relocs.

Link: https://github.com/ClangBuiltLinux/linux/issues/1057
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=a619b58721f0a03fd91c27670d3e4c2fb0d88f1e
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Linux 6.3

Linux 6.3-rc7

Linux 6.3-rc6

Linux 6.3-rc5

Linux 6.3-rc4

Linux 6.3-rc3

kbuild: use git-archive for source package creation

Commit 5c3d1d0abb12 ("kbuild: add a tool to list files ignored by git")
added a new tool, scripts/list-gitignored. My intention was to create
source packages without cleaning the source tree, without relying on git.

Linus strongly objected to it, and suggested using 'git archive' instead.
[1] [2] [3]

This commit goes in that direction - Remove scripts/list-gitignored.c
and rewrites Makefiles and scripts to use 'git archive' for building
Debian and RPM source packages. It also makes 'make perf-tar*-src-pkg'
use 'git archive' again.

Going forward, building source packages is only possible in a git-managed
tree. Building binary packages does not require git.

[1]: https://lore.kernel.org/lkml/CAHk-=wi49sMaC7vY1yMagk7eqLK=1jHeHQ=yZ_k45P=xBccnmA@mail.gmail.com/
[2]: https://lore.kernel.org/lkml/CAHk-=wh5AixGsLeT0qH2oZHKq0FLUTbyTw4qY921L=PwYgoGVw@mail.gmail.com/
[3]: https://lore.kernel.org/lkml/CAHk-=wgM-W6Fu==EoAVCabxyX8eYBz9kNC88-tm9ExRQwA79UQ@mail.gmail.com/

Fixes: 5c3d1d0abb12 ("kbuild: add a tool to list files ignored by git")
Fixes: e0ca16749ac3 ("kbuild: make perf-tar*-src-pkg work without relying on git")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: rpm-pkg: move source components to rpmbuild/SOURCES

Prepare to add more files to the source RPM.

Also, fix the build error when KCONFIG_CONFIG is set:
error: Bad file: ./.config: No such file or directory

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

Makefile: Make kernelrelease target work with M=

That commit required the use of filechk_kernel.release for the
kernelrelease Makefile target. It is currently only being set when
KBUILD_EXTMOD is not set. Make sure it is set in that case as well.

Fixes: 1cb86b6c3136 ("kbuild: save overridden KERNELRELEASE in include/config/kernel.release")
Signed-off-by: Tzafrir Cohen <nvidia@cohens.org.il>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Linux 6.3-rc2

Linux 6.3-rc1

kbuild: add a tool to list files ignored by git

In short, the motivation of this commit is to build a source package
without cleaning the source tree.

The deb-pkg and (src)rpm-pkg targets first run 'make clean' before
creating a source tarball. Otherwise build artifacts such as *.o,
*.a, etc. would be included in the tarball. Yet, the tarball ends up
containing several garbage files since 'make clean' does not clean
everything.

Cleaning the tree every time is annoying since it makes the incremental
build impossible. It is desirable to create a source tarball without
cleaning the tree.

In fact, there are some ways to achieve this.

The easiest solution is 'git archive'. 'make perf-tar*-src-pkg' uses
it, but I do not like it because it works only when the source tree is
managed by git, and all files you want in the tarball must be committed
in advance.

I want to make it work without relying on git. We can do this.

Files that are ignored by git are generated files, so should be excluded
from the source tarball. We can list them out by parsing the .gitignore
files. Of course, .gitignore does not cover all the cases, but it works
well enough.

tar(1) claims to support it:

--exclude-vcs-ignores

Exclude files that match patterns read from VCS-specific ignore files.
Supported files are: .cvsignore, .gitignore, .bzrignore, and .hgignore.

The best scenario would be to use 'tar --exclude-vcs-ignores', but this
option does not work. --exclude-vcs-ignore does not understand any of
the negation (!), preceding slash, following slash, etc.. So, this option
is just useless.

Hence, I wrote this gitignore parser. The previous version [1], written
in Python, was so slow. This version is implemented in C, so it works
much faster.

I imported the code from git (commit: 23c56f7bd5f1), so we get the same
result.

This tool traverses the source tree, parsing all .gitignore files, and
prints file paths that are ignored by git.

The output is similar to 'git ls-files --ignored --directory --others
--exclude-per-directory=.gitignore', except

[1] Not sorted
[2] No trailing slash for directories

[2] is intentional because tar's --exclude-from option cannot handle
trailing slashes.

[How to test this tool]

$ git clean -dfx
$ make -s -j$(nproc) defconfig all # or allmodconifg or whatever
$ git archive -o ../linux1.tar --prefix=./ HEAD
$ tar tf ../linux1.tar | LANG=C sort > ../file-list1 # files emitted by 'git archive'
$ make scripts_package
HOSTCC scripts/list-gitignored
$ scripts/list-gitignored --prefix=./ -o ../exclude-list
$ tar cf ../linux2.tar --exclude-from=../exclude-list .
$ tar tf ../linux2.tar | LANG=C sort > ../file-list2 # files emitted by 'tar'
$ diff ../file-list1 ../file-list2 | grep -E '^(<|>)'
< ./Documentation/devicetree/bindings/.yamllint
< ./drivers/clk/.kunitconfig
< ./drivers/gpu/drm/tests/.kunitconfig
< ./drivers/hid/.kunitconfig
< ./fs/ext4/.kunitconfig
< ./fs/fat/.kunitconfig
< ./kernel/kcsan/.kunitconfig
< ./lib/kunit/.kunitconfig
< ./mm/kfence/.kunitconfig
< ./tools/testing/selftests/arm64/tags/
< ./tools/testing/selftests/arm64/tags/.gitignore
< ./tools/testing/selftests/arm64/tags/Makefile
< ./tools/testing/selftests/arm64/tags/run_tags_test.sh
< ./tools/testing/selftests/arm64/tags/tags_test.c
< ./tools/testing/selftests/kvm/.gitignore
< ./tools/testing/selftests/kvm/Makefile
< ./tools/testing/selftests/kvm/config
< ./tools/testing/selftests/kvm/settings

The source tarball contains most of files that are tracked by git. You
see some diffs, but it is just because some .gitignore files are wrong.

$ git ls-files -i -c --exclude-per-directory=.gitignore
Documentation/devicetree/bindings/.yamllint
drivers/clk/.kunitconfig
drivers/gpu/drm/tests/.kunitconfig
drivers/hid/.kunitconfig
fs/ext4/.kunitconfig
fs/fat/.kunitconfig
kernel/kcsan/.kunitconfig
lib/kunit/.kunitconfig
mm/kfence/.kunitconfig
tools/testing/selftests/arm64/tags/.gitignore
tools/testing/selftests/arm64/tags/Makefile
tools/testing/selftests/arm64/tags/run_tags_test.sh
tools/testing/selftests/arm64/tags/tags_test.c
tools/testing/selftests/kvm/.gitignore
tools/testing/selftests/kvm/Makefile
tools/testing/selftests/kvm/config
tools/testing/selftests/kvm/settings

[1]: https://lore.kernel.org/all/20230128173843.765212-1-masahiroy@kernel.org/

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

kbuild: remove --include-dir MAKEFLAG from top Makefile

I added $(srctree)/ to some included Makefiles in the following commits:

- 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefiles")
- d82856395505 ("kbuild: do not require sub-make for separate output tree builds")

They were a preparation for removing --include-dir flag.

I have never thought --include-dir useful. Rather, it _is_ harmful.

For example, run the following commands:

$ make -s ARCH=x86 mrproper defconfig
$ make ARCH=arm O=foo dtbs
make[1]: Entering directory '/tmp/linux/foo'
HOSTCC scripts/basic/fixdep
Error: kernelrelease not valid - run 'make prepare' to update it
UPD include/config/kernel.release
make[1]: Leaving directory '/tmp/linux/foo'

The first command configures the source tree for x86. The next command
tries to build ARM device trees in the separate foo/ directory - this
must stop because the directory foo/ has not been configured yet.

However, due to --include-dir=$(abs_srctree), the top Makefile includes
the wrong include/config/auto.conf from the source tree and continues
building. Kbuild traverses the directory tree, but of course it does
not work correctly. The Error message is also pointless - 'make prepare'
does not help at all for fixing the issue.

This commit fixes more arch Makefile, and finally removes --include-dir
from the top Makefile.

There are more breakages under drivers/, but I do not volunteer to fix
them all. I just moved --include-dir to drivers/Makefile.

With this commit, the second command will stop with a sensible message.

$ make -s ARCH=x86 mrproper defconfig
$ make ARCH=arm O=foo dtbs
make[1]: Entering directory '/tmp/linux/foo'
SYNC include/config/auto.conf.cmd
***
*** The source tree is not clean, please run 'make ARCH=arm mrproper'
*** in /tmp/linux
***
make[2]: *** [../Makefile:646: outputmakefile] Error 1
/tmp/linux/Makefile:770: include/config/auto.conf.cmd: No such file or directory
make[1]: *** [/tmp/linux/Makefile:793: include/config/auto.conf.cmd] Error 2
make[1]: Leaving directory '/tmp/linux/foo'
make: *** [Makefile:226: __sub-make] Error 2

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

kbuild: fix trivial typo in comment

Add missing underscore in CONFIG_DEBUG_INFO_BTF_MODULES.

Fixes: f73edc8951b2 ("kbuild: unify two modpost invocations")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

powerpc/vdso: Filter clang's auto var init zero enabler when linking

After commit 8d9acfce3332 ("kbuild: Stop using '-Qunused-arguments' with
clang"), the PowerPC vDSO shows the following error with clang-13 and
older when CONFIG_INIT_STACK_ALL_ZERO is enabled:

clang: error: argument unused during compilation: '-enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang' [-Werror,-Wunused-command-line-argument]

clang-14 added a change to make sure this flag never triggers
-Wunused-command-line-argument, so it is fixed with newer releases. For
older releases that the kernel still supports building with, just filter
out this flag, as has been done for other flags.

Fixes: f0a42fbab447 ("powerpc/vdso: Improve linker flags")
Fixes: 8d9acfce3332 ("kbuild: Stop using '-Qunused-arguments' with clang")
Link: https://github.com/llvm/llvm-project/commit/ca6d5813d17598cd180995fb3bdfca00f364475f
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: save overridden KERNELRELEASE in include/config/kernel.release

${KERNELRELEASE} is used as a part of the installation path.
(INSTALL_DTBS_PATH, MODLIB, etc.)

When KERNELRELEASE is overridden from the command line, it should be
saved in include/config/kernel.release, so that it will be consistently
used for the installation steps.

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

setlocalversion: absorb $(KERNELVERSION)

Print $(KERNELVERSION) in setlocalversion so that the callers get
simpler.

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

kbuild: Stop using '-Qunused-arguments' with clang

This option masks all unused command line argument warnings, which can
hide potential issues, such as an architecture Makefile adding an
unsupported flag to KBUILD_AFLAGS or KBUILD_CFLAGS, which will cause all
as-option and cc-options to silently fail due to -Werror with no
indication as to why in the main kernel build.

Remove this flag so that warnings of this nature can be caught early and
obviously in a build.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: also delete temporary directories

Reuse the standard naming schema for temporary files also for temporary
directories.

Such a directory will be used by the kheaders generation.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: rust: move rust/target.json to scripts/

scripts/ is a better place to generate files used treewide.

With target.json moved to scripts/, you do not need to add target.json
to no-clean-files or MRPROPER_FILES.

'make clean' does not visit scripts/, but 'make mrproper' does.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>

kbuild: make W=1 warn files that are tracked but ignored by git

The top .gitignore comments about how to detect files breaking
.gitignore rules, but people rarely care about it.

Add a new W=1 warning to detect files that are tracked but ignored by
git. If git is not installed or the source tree is not tracked by git
at all, this script does not print anything.

Running it on v6.2-rc1 detected the following:

$ make W=1 misc-check
Documentation/devicetree/bindings/.yamllint: warning: ignored by one of the .gitignore files
drivers/clk/.kunitconfig: warning: ignored by one of the .gitignore files
drivers/gpu/drm/tests/.kunitconfig: warning: ignored by one of the .gitignore files
drivers/hid/.kunitconfig: warning: ignored by one of the .gitignore files
fs/ext4/.kunitconfig: warning: ignored by one of the .gitignore files
fs/fat/.kunitconfig: warning: ignored by one of the .gitignore files
kernel/kcsan/.kunitconfig: warning: ignored by one of the .gitignore files
lib/kunit/.kunitconfig: warning: ignored by one of the .gitignore files
mm/kfence/.kunitconfig: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/.gitignore: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/Makefile: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/run_tags_test.sh: warning: ignored by one of the .gitignore files
tools/testing/selftests/arm64/tags/tags_test.c: warning: ignored by one of the .gitignore files

These are ignored by the '.*' or 'tags' in the top .gitignore, but
there is no rule to negate it.

You might be tempted to do 'git add -f' but I want to have the real
issue fixed (by fixing a .gitignore, or by renaming files, etc.).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: drop V=0 support

The top Makefile sets KBUILD_VERBOSE to 0 by default, it looks weird
now because V=1 and V=2 can be OR'ed as V=12. The default should be
empty.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: allow to combine multiple V= levels

Commit a6de553da01c ("kbuild: Allow to combine multiple W= levels")
supported W=123 to enable all the extra warning groups.

I think a similar idea is applicable to the V= option.

V=1 echos the whole command
V=2 prints the reason for rebuilding

These are orthogonal, and can be enabled at the same time.

This commit supports V=12 to enable both of them.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: print short log in addition to the whole command with V=1

"make V=1" prints the whole command instead of the short log, but I
think it is nicer to print both so that you can easily spot the build
rule of your interest.

This commit changes V=1 to print the short log (the line starts with
'#'), followed by the full log.

In parallel builds, the short/full logs from the same build rule may
be interspersed. If you want to avoid it, please add -Otarget option.
Kbuild will never set it by default because Make would buffer the logs
and lose the escape sequences. (Modern compilers print warnings and
errors in color, but only when they write to a terminal.)

This is also a preparation for supporting V=12 because V=2 appends the
reason for rebuilding to the short log.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: refactor silent mode detection

Factor out $(findstring s,...).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: Optionally enable schema checks for %.dtb targets

While not documented, schema checks for single dtb targets mostly work
already by setting 'CHECK_DTBS=1'. However, the dependencies are not
handled and it only works if 'make dt_bindings_check' was run first and
generated processed-schema.json. In addition, changing a binding file
doesn't cause the schema to be rebuilt and dtb to be revalidated.

Making this work turns out to be simple. Whenever CHECK_DTBS is set,
make 'dt_binding_check' a 'dtbs_prepare' dependency.

I reimplemented here what Masahiro had originally come up with a while
back.

Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20221220013233.2890335-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

rust: delete rust-project.json when running make clean

rust-project.json is the configuration file used by rust-analyzer.
As it is a configuration file and it is not needed to build external
modules, it should be delete by make clean. So, delete rust-project.json
when running make clean.

Link: https://github.com/Rust-for-Linux/linux/issues/939
Suggested-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Finn Behrens <fin@nyantec.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Linux 6.2

Linux 6.2-rc8

Linux 6.2-rc7

Linux 6.2-rc6

Linux 6.2-rc5

kbuild: fix 'make modules' error when CONFIG_DEBUG_INFO_BTF_MODULES=y

When CONFIG_DEBUG_INFO_BTF_MODULES=y, running 'make modules'
in the clean kernel tree will get the following error.

$ grep CONFIG_DEBUG_INFO_BTF_MODULES .config
CONFIG_DEBUG_INFO_BTF_MODULES=y
$ make -s clean
$ make modules
[snip]
AR vmlinux.a
ar: ./built-in.a: No such file or directory
make: *** [Makefile:1241: vmlinux.a] Error 1

'modules' depends on 'vmlinux', but builtin objects are not built.

Define KBUILD_BUILTIN.

Fixes: f73edc8951b2 ("kbuild: unify two modpost invocations")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: export top-level LDFLAGS_vmlinux only to scripts/Makefile.vmlinux

Nathan Chancellor reports that $(NM) emits an error message when
GNU Make 4.4 is used to build the ARM zImage.

$ make-4.4 ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- O=build defconfig zImage
[snip]
LD vmlinux
NM System.map
SORTTAB vmlinux
OBJCOPY arch/arm/boot/Image
Kernel: arch/arm/boot/Image is ready
arm-linux-gnueabi-nm: 'arch/arm/boot/compressed/../../../../vmlinux': No such file
/bin/sh: 1: arithmetic expression: expecting primary: " "
LDS arch/arm/boot/compressed/vmlinux.lds
AS arch/arm/boot/compressed/head.o
GZIP arch/arm/boot/compressed/piggy_data
AS arch/arm/boot/compressed/piggy.o
CC arch/arm/boot/compressed/misc.o

This occurs since GNU Make commit 98da874c4303 ("[SV 10593] Export
variables to $(shell ...) commands"), and the O= option is needed to
reproduce it. The generated zImage is correct despite the error message.

As the commit description of 98da874c4303 [1] says, exported variables
are passed down to $(shell ) functions, which means exported recursive
variables might be expanded earlier than before, in the parse stage.

The following test code demonstrates the change for GNU Make 4.4.

[Test Makefile]

$(shell echo hello > foo)
export foo = $(shell cat bar/../foo)
$(shell mkdir bar)

all:
@echo $(foo)

[GNU Make 4.3]

$ rm -rf bar; make-4.3
hello

[GNU Make 4.4]

$ rm -rf bar; make-4.4
cat: bar/../foo: No such file or directory
hello

The 'foo' is a resursively expanded (i.e. lazily expanded) variable.

GNU Make 4.3 expands 'foo' just before running the recipe '@echo $(foo)',
at this point, the directory 'bar' exists.

GNU Make 4.4 expands 'foo' to evaluate $(shell mkdir bar) because it is
exported. At this point, the directory 'bar' does not exit yet. The cat
command cannot resolve the bar/../foo path, hence the error message.

Let's get back to the kernel Makefile.

In arch/arm/boot/compressed/Makefile, KBSS_SZ is referenced by
LDFLAGS_vmlinux, which is recursive and also exported by the top
Makefile.

GNU Make 4.3 expands KBSS_SZ just before running the recipes, so no
error message.

GNU Make 4.4 expands KBSS_SZ in the parse stage, where the directory
arm/arm/boot/compressed does not exit yet. When compiled with O=,
the output directory is created by $(shell mkdir -p $(obj-dirs))
in scripts/Makefile.build.

There are two ways to fix this particular issue:

- change "$(obj)/../../../../vmlinux" in KBSS_SZ to "vmlinux"
- unexport LDFLAGS_vmlinux

This commit takes the latter course because it is what I originally
intended.

Commit 3ec8a5b33dea ("kbuild: do not export LDFLAGS_vmlinux")
unexported LDFLAGS_vmlinux.

Commit 5d4aeffbf709 ("kbuild: rebuild .vmlinux.export.o when its
prerequisite is updated") accidentally exported it again.

We can clean up arch/arm/boot/compressed/Makefile later.

[1]: https://git.savannah.gnu.org/cgit/make.git/commit/?id=98da874c43035a490cdca81331724f233a3d0c9a

Link: https://lore.kernel.org/all/Y7i8+EjwdnhHtlrr@dev-arch.thelio-3990X/
Fixes: 5d4aeffbf709 ("kbuild: rebuild .vmlinux.export.o when its prerequisite is updated")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>

Linux 6.2-rc4

Linux 6.2-rc3

kbuild: fix single *.ko build

The single *.ko build is broken since commit f65a486821cf ("kbuild:
change module.order to list *.o instead of *.ko").

Fixes: f65a486821cf ("kbuild: change module.order to list *.o instead of *.ko")
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>

Linux 6.2-rc2

kbuild: sort single-targets alphabetically again

This was previously alphabetically sorted. Sort it again.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Linux 6.2-rc1

kbuild: ensure Make >= 3.82 is used

Documentation/process/changes.rst notes the minimal GNU Make version,
but it is not checked anywhere.

We could check $(MAKE_VERSION), but another simple way is to check
$(.FEATURES) since the feature list always grows.

GNU Make 3.81 expands $(.FEATURES) to:
target-specific order-only second-expansion else-if archives jobserver check-symlink

GNU Make 3.82 expands $(.FEATURES) to:
target-specific order-only second-expansion else-if shortest-stem undefine archives jobserver check-symlink

To ensure Make >= 3.82, you can check either 'shortest-stem' or
'undefine'.

This way is not always possible. For example, Make 4.0 through 4.2 have
the same set of $(.FEATURES). At that point, we will need to come up
with a different approach.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: change module.order to list *.o instead of *.ko

scripts/Makefile.build replaces the suffix .o with .ko, then
scripts/Makefile.modpost calls the sed command to change .ko back
to the original .o suffix.

Instead of converting the suffixes back-and-forth, store the .o paths
in modules.order, and replace it with .ko in 'make modules_install'.

This avoids the unneeded sed command.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>

kbuild: add read-file macro

Since GNU Make 4.2, $(file ...) supports the read operater '<', which
is useful to read a file without forking a new process. No warning is
shown even if the input file is missing.

For older Make versions, it falls back to the cat command.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Tested-by: Alexander Lobakin <alexandr.lobakin@intel.com>

kbuild: add test-{ge,gt,le,lt} macros

GNU Make 4.4 introduced $(intcmp ...), which is useful to compare two
integers without forking a new process.

Add test-{ge,gt,le,lt} macros, which work more efficiently with GNU
Make >= 4.4. For older Make versions, they fall back to the 'test'
shell command.

The first two parameters to $(intcmp ...) must not be empty. To avoid
the syntax error, I appended '0' to them. Fortunately, '00' is treated
as '0'. This is needed because CONFIG options may expand to an empty
string when the kernel configuration is not included.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: move -Werror from KBUILD_CFLAGS to KBUILD_CPPFLAGS

CONFIG_WERROR turns warnings into errors, which happens only for *.c
files because -Werror is added to KBUILD_CFLAGS.

Adding it to KBUILD_CPPFLAGS makes more sense because preprocessors
understand the -Werror option.

For example, you can put a #warning directive in any preprocessed code.

warning: #warning "this is a warning message" [-Wcpp]

If -Werror is added, it is promoted to an error.

error: #warning "this is a warning message" [-Werror=cpp]

This commit moves -Werror to KBUILD_CPPFLAGS so it works in the same way
for *.c, *.S, *.lds.S or whatever needs preprocessing.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

kbuild: Port silent mode detection to future gnu make.

Port silent mode detection to the future (post make-4.4) versions of gnu make.

Makefile contains the following piece of make code to detect if option -s is
specified on the command line.

ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)

This code is executed by make at parse time and assumes that MAKEFLAGS
does not contain command line variable definitions.
Currently if the user defines a=s on the command line, then at build only
time MAKEFLAGS contains " -- a=s".
However, starting with commit dc2d963989b96161472b2cd38cef5d1f4851ea34
MAKEFLAGS contains command line definitions at both parse time and
build time.

This '-s' detection code then confuses a command line variable
definition which contains letter 's' with option -s.

$ # old make
$ make net/wireless/ocb.o a=s
CALL scripts/checksyscalls.sh
DESCEND objtool
$ # this a new make which defines makeflags at parse time
$ ~/src/gmake/make/l64/make net/wireless/ocb.o a=s
$

We can see here that the letter 's' from 'a=s' was confused with -s.

This patch checks for presence of -s using a method recommended by the
make manual here
https://www.gnu.org/software/make/manual/make.html#Testing-Flags.

Link: https://lists.gnu.org/archive/html/bug-make/2022-11/msg00190.html
Reported-by: Jan Palus <jpalus+gnu@fastmail.com>
Signed-off-by: Dmitry Goncharov <dgoncharov@users.sf.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

objtool: Add --mnop as an option to --mcount

Some architectures (powerpc) may not support ftrace locations being nop'ed
out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as
a means for architectures to enable nop'ing of ftrace locations. Add --mnop
as an option to objtool --mcount, to indicate support for the same.

Also, make sure that --mnop can be passed as an option to objtool only when
--mcount is passed.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-12-sv@linux.ibm.com

kbuild: upgrade the orphan section warning to an error if CONFIG_WERROR is set

Andrew Cooper suggested upgrading the orphan section warning to a hard link
error. However Nathan Chancellor said outright turning the warning into an
error with no escape hatch might be too aggressive, as we have had these
warnings triggered by new compiler generated sections, and suggested turning
orphan sections into an error only if CONFIG_WERROR is set. Kees Cook echoed
and emphasized that the mandate from Linus is that we should avoid breaking
builds. It wrecks bisection, it causes problems across compiler versions, etc.

Thus upgrade the orphan section warning to a hard link error only if
CONFIG_WERROR is set.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Xin Li <xin3.li@intel.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221025073023.16137-2-xin3.li@intel.com

arch: Introduce CONFIG_FUNCTION_ALIGNMENT

Generic function-alignment infrastructure.

Architectures can select FUNCTION_ALIGNMENT_xxB symbols; the
FUNCTION_ALIGNMENT symbol is then set to the largest such selected
size, 0 otherwise.

From this the -falign-functions compiler argument and __ALIGN macro
are set.

This incorporates the DEBUG_FORCE_FUNCTION_ALIGN_64B knob and future
alignment requirements for x86_64 (later in this series) into a single
place.

NOTE: also removes the 0x90 filler byte from the generic __ALIGN
primitive, that value makes no sense outside of x86.

NOTE: .balign 0 reverts to a no-op.

Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111143.719248727@infradead.org

doc: add texinfodocs and infodocs targets

Sphinx supports generating Texinfo sources and Info documentation,
which can be navigated easily and is convenient to search (via the
indexed nodes or anchors, for example).

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
Link: https://lore.kernel.org/r/20221116190210.28407-2-maxim.cournoyer@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kbuild: treat char as always unsigned

Recently, some compile-time checking I added to the clamp_t family of
functions triggered a build error when a poorly written driver was
compiled on ARM, because the driver assumed that the naked `char` type
is signed, but ARM treats it as unsigned, and the C standard says it's
architecture-dependent.

I doubt this particular driver is the only instance in which
unsuspecting authors make assumptions about `char` with no `signed` or
`unsigned` specifier. We were lucky enough this time that that driver
used `clamp_t(char, negative_value, positive_value)`, so the new
checking code found it, and I've sent a patch to fix it, but there are
likely other places lurking that won't be so easily unearthed.

So let's just eliminate this particular variety of heisensign bugs
entirely. Set `-funsigned-char` globally, so that gcc makes the type
unsigned on all architectures.

This will break things in some places and fix things in others, so this
will likely cause a bit of churn while reconciling the type misuse.

Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/lkml/202210190108.ESC3pc3D-lkp@intel.com/
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

kbuild: Cleanup DT Overlay intermediate files as appropriate

%.dtbo.o and %.dtbo.S files are used to build-in DT Overlay. They should
should not be removed by Make or the kernel will be needlessly rebuilt.

These should be removed by "clean" and ignored by git like other
intermediate files.

Reported-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Andrew Davis <afd@ti.com>
Fixes: 941214a512d8 ("kbuild: Allow DTB overlays to built into .dtbo.S files")
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20221114205939.27994-1-afd@ti.com
Signed-off-by: Rob Herring <robh@kernel.org>

scs: add support for dynamic shadow call stacks

In order to allow arches to use code patching to conditionally emit the
shadow stack pushes and pops, rather than always taking the performance
hit even on CPUs that implement alternatives such as stack pointer
authentication on arm64, add a Kconfig symbol that can be set by the
arch to omit the SCS codegen itself, without otherwise affecting how
support code for SCS and compiler options (for register reservation, for
instance) are emitted.

Also, add a static key and some plumbing to omit the allocation of
shadow call stack for dynamic SCS configurations if SCS is disabled at
runtime.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20221027155908.1940624-3-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

Linux 6.1

Linux 6.1-rc8

Linux 6.1-rc7

Linux 6.1-rc6

Linux 6.1-rc5

Linux 6.1-rc4

kbuild: fix SIGPIPE error message for AR=gcc-ar and AR=llvm-ar

Jiri Slaby reported that building the kernel with AR=gcc-ar shows:
/usr/bin/ar terminated with signal 13 [Broken pipe]

Nathan Chancellor reported the latest AR=llvm-ar shows:
error: write on a pipe with no reader

The latter occurs since LLVM commit 51b557adc131 ("Add an error message
to the default SIGPIPE handler").

The resulting vmlinux is correct, but it is better to silence it.

'head -n1' exits after reading the first line, so the pipe is closed.

Use 'sed -n 1p' to eat the stream till the end.

Fixes: 321648455061 ("kbuild: use obj-y instead extra-y for objects placed at the head")
Link: https://github.com/ClangBuiltLinux/linux/issues/1651
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>

kbuild: use POSIX-compatible grep option

--file is a GNU extension to grep which is not available in all
implementations (such as BusyBox). Use the -f option instead which is
eqvuialent according to the GNU grep manpage[1] and is present in
POSIX[2].

[1] https://www.gnu.org/software/grep/manual/grep.html
[2] https://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html

Signed-off-by: Stefan Hansson <newbie13xd@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Linux 6.1-rc3

Linux 6.1-rc2

Linux 6.1-rc1

kbuild: fix single directory build

Commit f110e5a250e3 ("kbuild: refactor single builds of *.ko") was wrong.

KBUILD_MODULES _is_ needed for single builds.

Otherwise, "make foo/bar/baz/" does not build module objects at all.

Fixes: f110e5a250e3 ("kbuild: refactor single builds of *.ko")
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: David Sterba <dsterba@suse.com>

kmsan: add KMSAN runtime core

For each memory location KernelMemorySanitizer maintains two types of
metadata:

1. The so-called shadow of that location - а byte:byte mapping describing
whether or not individual bits of memory are initialized (shadow is 0)
or not (shadow is 1).
2. The origins of that location - а 4-byte:4-byte mapping containing
4-byte IDs of the stack traces where uninitialized values were
created.

Each struct page now contains pointers to two struct pages holding KMSAN
metadata (shadow and origins) for the original struct page. Utility
routines in mm/kmsan/core.c and mm/kmsan/shadow.c handle the metadata
creation, addressing, copying and checking. mm/kmsan/report.c performs
error reporting in the cases an uninitialized value is used in a way that
leads to undefined behavior.

KMSAN compiler instrumentation is responsible for tracking the metadata
along with the kernel memory. mm/kmsan/instrumentation.c provides the
implementation for instrumentation hooks that are called from files
compiled with -fsanitize=kernel-memory.

To aid parameter passing (also done at instrumentation level), each
task_struct now contains a struct kmsan_task_state used to track the
metadata of function parameters and return values for that task.

Finally, this patch provides CONFIG_KMSAN that enables KMSAN, and declares
CFLAGS_KMSAN, which are applied to files compiled with KMSAN. The
KMSAN_SANITIZE:=n Makefile directive can be used to completely disable
KMSAN instrumentation for certain files.

Similarly, KMSAN_ENABLE_CHECKS:=n disables KMSAN checks and makes newly
created stack memory initialized.

Users can also use functions from include/linux/kmsan-checks.h to mark
certain memory regions as uninitialized or initialized (this is called
"poisoning" and "unpoisoning") or check that a particular region is
initialized.

Link: https://lkml.kernel.org/r/20220915150417.722975-12-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Revert "kbuild: Check if linker supports the -X option"

This reverts commit d79a27195a33f4b5e591de5536799ad874ea6cf5.

According to the commit description, this ld-option test was added for
the gold linker at that time.

Commit 75959d44f9dc ("kbuild: Fail if gold linker is detected") gave
up the gold linker support after all.

I tested the BFD linker from binutils 2.23 and LLD from LLVM 11.0.0.
Both of them support the -X option.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: rebuild .vmlinux.export.o when its prerequisite is updated

When include/linux/export-internal.h is updated, .vmlinux.export.o
must be rebuilt, but it does not happen because its rule is hidden
behind scripts/link-vmlinux.sh.

Move it out of the shell script, so that Make can see the dependency
between vmlinux and .vmlinux.export.o.

Move the vmlinux rule to scripts/Makefile.vmlinux.

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

kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o

Do not build modules.builtin(.modinfo) as a side-effect of vmlinux.

There are no good reason to rebuild them just because any of vmlinux's
prerequistes (vmlinux.lds, .vmlinux.export.c, etc.) has been updated.

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

kbuild: remove head-y syntax

Kbuild puts the objects listed in head-y at the head of vmlinux.
Conventionally, we do this for head*.S, which contains the kernel entry
point.

A counter approach is to control the section order by the linker script.
Actually, the code marked as __HEAD goes into the ".head.text" section,
which is placed before the normal ".text" section.

I do not know if both of them are needed. From the build system
perspective, head-y is not mandatory. If you can achieve the proper code
placement by the linker script only, it would be cleaner.

I collected the current head-y objects into head-object-list.txt. It is
a whitelist. My hope is it will be reduced in the long run.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: use obj-y instead extra-y for objects placed at the head

The objects placed at the head of vmlinux need special treatments:

- arch/$(SRCARCH)/Makefile adds them to head-y in order to place
them before other archives in the linker command line.

- arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of
obj-y to avoid them going into built-in.a.

This commit gets rid of the latter.

Create vmlinux.a to collect all the objects that are unconditionally
linked to vmlinux. The objects listed in head-y are moved to the head
of vmlinux.a by using 'ar m'.

With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y
for builtin objects.

There is no *.o that is directly linked to vmlinux. Drop unneeded code
in scripts/clang-tools/gen_compile_commands.py.

$(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested
by Nathan Chancellor [1].

[1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: hide error checker logs for V=1 builds

V=1 (verbose build) shows commands executed by Make, but it may cause
misunderstanding.

For example, the following command shows the outstanding error message.

$ make V=1 INSTALL_PATH=/tmp install
test -e include/generated/autoconf.h -a -e include/config/auto.conf || ( \
echo >&2; \
echo >&2 " ERROR: Kernel configuration is invalid."; \
echo >&2 " include/generated/autoconf.h or include/config/auto.conf are missing.";\
echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
echo >&2 ; \
/bin/false)
unset sub_make_done; ./scripts/install.sh

It is not an error. Make just showed the recipe lines it has executed,
but people may think that 'make install' has failed.

Likewise, the combination of V=1 and O= shows confusing
"*** The source tree is not clean, please run 'make mrproper'".

Suppress such misleading logs.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: unify two modpost invocations

Currently, modpost is executed twice; first for vmlinux, second
for modules.

This commit merges them.

Current build flow
==================

1) build obj-y and obj-m objects
2) link vmlinux.o
3) modpost for vmlinux
4) link vmlinux
5) modpost for modules
6) link modules (*.ko)

The build steps 1) through 6) are serialized, that is, modules are
built after vmlinux. You do not get benefits of parallel builds when
scripts/link-vmlinux.sh is being run.

New build flow
==============

1) build obj-y and obj-m objects
2) link vmlinux.o
3) modpost for vmlinux and modules
4a) link vmlinux
4b) link modules (*.ko)

In the new build flow, modpost is invoked just once.

vmlinux and modules are built in parallel. One exception is
CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: move vmlinux.o rule to the top Makefile

Move the build rules of vmlinux.o out of scripts/link-vmlinux.sh to
clearly separate 1) pre-modpost, 2) modpost, 3) post-modpost stages.
This will make further refactoring possible.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: move .vmlinux.objs rule to Makefile.modpost

.vmlinux.objs is used by modpost, so scripts/Makefile.modpost is
a better place to generate it.

It is used only when CONFIG_MODVERSIONS=y. It should be guarded
by "ifdef CONFIG_MODVERSIONS".

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: list sub-directories in ./Kbuild

Use the ordinary obj-y syntax to list subdirectories.

Note1:
Previously, the link order of lib-y depended on CONFIG_MODULES; lib-y
was linked before drivers-y when CONFIG_MODULES=y, otherwise after
drivers-y. This was a bug of commit 7273ad2b08f8 ("kbuild: link lib-y
objects to vmlinux forcibly when CONFIG_MODULES=y"), but it was not a
big deal after all. Now, all objects listed in lib-y are linked last,
irrespective of CONFIG_MODULES.

Note2:
Finally, the single target build in arch/*/lib/ works correctly. There was
a bug report about this. [1]

$ make ARCH=arm arch/arm/lib/findbit.o
CALL scripts/checksyscalls.sh
AS arch/arm/lib/findbit.o

[1]: https://lore.kernel.org/linux-kbuild/YvUQOwL6lD4%2F5%2FU6@shell.armlinux.org.uk/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Makefile.compiler: replace cc-ifversion with compiler-specific macros

cc-ifversion is GCC specific. Replace it with compiler specific
variants. Update the users of cc-ifversion to use these new macros.

Link: https://github.com/ClangBuiltLinux/linux/issues/350
Link: https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@mail.gmail.com/
Suggested-by: Bill Wendling <morbo@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: fix and refactor single target build

The single target build has a subtle bug for the combination for
an individual file and a subdirectory.

[1] 'make kernel/fork.i' builds only kernel/fork.i

$ make kernel/fork.i
CALL scripts/checksyscalls.sh
DESCEND objtool
CPP kernel/fork.i

[2] 'make kernel/' builds only under the kernel/ directory.

$ make kernel/
CALL scripts/checksyscalls.sh
DESCEND objtool
CC kernel/fork.o
CC kernel/exec_domain.o
[snip]
CC kernel/rseq.o
AR kernel/built-in.a

But, if you try to do [1] and [2] in a single command, you will get
only [1] with a weird log:

$ make kernel/fork.i kernel/
CALL scripts/checksyscalls.sh
DESCEND objtool
CPP kernel/fork.i
make[2]: Nothing to be done for 'kernel/'.

With 'make kernel/fork.i kernel/', you should get both [1] and [2].

Rewrite the single target build.

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

kbuild: generate include/generated/compile.h in top Makefile

Now that UTS_VERSION was separated out, this header can be generated
much earlier, and probably the top Makefile is a better place to do it
than init/Makefile.

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

kbuild: move 'PHONY += modules_prepare' to the common part

Unify the code between in-tree builds and external module builds.

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

kbuild: refactor single builds of *.ko

Remove the potentially invalid modules.order instead of using
the temporary file.

Also, KBUILD_MODULES is don't care for single builds. No need to
cancel it.

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

kbuild: remove duplicated dependency between modules and modules_check

The dependency, "modules: modules_check" is specified twice.
Commit 1a998be620a1 ("kbuild: check module name conflict for external
modules as well") missed to clean it up.

'PHONY += modules' also appears twice.

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

kbuild: do not deduplicate modules.order

The AWK code was added to deduplicate modules.order in case $(obj-m)
contains the same module multiple times, but it is actually unneeded
since commit b2c885549122 ("kbuild: update modules.order only when
contained modules are updated").

The list is already deduplicated before being processed by AWK because
$^ is the deduplicated list of prerequisites.
(Please note the real-prereqs macro uses $^)

Yet, modules.order will contain duplication if two different Makefiles
build the same module:

foo/Makefile:

obj-m += bar/baz.o

foo/bar/Makefile:

obj-m += baz.o

However, the parallel builds cannot properly handle this case in the
first place. So, it is better to let it fail (as already done by
scripts/modules-check.sh).

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

kbuild: check sha1sum just once for each atomic header

It is unneeded to check the sha1sum every time.

Create the timestamp files to manage it.

Add '.' to clean-dirs because 'make clean' must visit ./Kbuild to
clean up the timestamp files.

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

kbuild: hard-code KBUILD_ALLDIRS in scripts/Makefile.package

My future plan is to list subdirectories in ./Kbuild. When it occurs,
$(vmlinux-alldirs) will not contain all subdirectories.

Let's hard-code the directory list until I get around to implementing
a more sophisticated way for generating a source tarball.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: add phony targets to ./Kbuild

missing-syscalls and old-atomics are meant to be phony targets.
Adding them to always-y is odd. (always-y should generate something).

Add a new phony target 'prepare', which depends on all the other.

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

dt: Add a check for undocumented compatible strings in kernel

Add a make target, dt_compatible_check, to extract compatible strings
from kernel sources and check if they are documented by a schema.
At least version v2022.08 of dtschema with dt-check-compatible is
required.

This check can also be run manually on specific files or directories:

scripts/dtc/dt-extract-compatibles drivers/clk/ | \
xargs dt-check-compatible -v -s Documentation/devicetree/bindings/processed-schema.json

Currently, there are about 3800 undocumented compatible strings. Most of
these are cases where the binding is not yet converted (given there
are 1900 .txt binding files remaining).

Link: https://lore.kernel.org/all/20220916012510.2718170-1-robh@kernel.org/
Signed-off-by: Rob Herring <robh@kernel.org>

Linux 6.0

hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero

Now that Clang's -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
option is no longer required, remove it from the command line. Clang 16
and later will warn when it is used, which will cause Kconfig to think
it can't use -ftrivial-auto-var-init=zero at all. Check for whether it
is required and only use it when so.

Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-kbuild@vger.kernel.org
Cc: llvm@lists.linux.dev
Cc: stable@vger.kernel.org
Fixes: f02003c860d9 ("hardening: Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO")
Signed-off-by: Kees Cook <keescook@chromium.org>

Kbuild: add Rust support

Having most of the new files in place, we now enable Rust support
in the build system, including `Kconfig` entries related to Rust,
the Rust configuration printer and a few other bits.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Douglas Su <d0u9.su@outlook.com>
Signed-off-by: Douglas Su <d0u9.su@outlook.com>
Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Co-developed-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Co-developed-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Co-developed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

cfi: Switch to -fsanitize=kcfi

Switch from Clang's original forward-edge control-flow integrity
implementation to -fsanitize=kcfi, which is better suited for the
kernel, as it doesn't require LTO, doesn't use a jump table that
requires altering function references, and won't break cross-module
function address equality.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-6-samitolvanen@google.com

Linux 6.0-rc7

Linux 6.0-rc6

Linux 6.0-rc5

kbuild: disable header exports for UML in a straightforward way

Previously 'make ARCH=um headers' stopped because of missing
arch/um/include/uapi/asm/Kbuild.

The error is not shown since commit ed102bf2afed ("um: Fix W=1
missing-include-dirs warnings") added arch/um/include/uapi/asm/Kbuild.

Hard-code the unsupported architecture, so it works like before.

Fixes: ed102bf2afed ("um: Fix W=1 missing-include-dirs warnings")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Richard Weinberger <richard@nod.at>

Linux 6.0-rc4

Linux 6.0-rc3

Linux 6.0-rc2

kbuild: fix the modules order between drivers and libs

Commit b2c885549122 ("kbuild: update modules.order only when contained
modules are updated") accidentally changed the modules order.

Prior to that commit, the modules order was determined based on
vmlinux-dirs, which lists core-y/m, drivers-y/m, libs-y/m, in this order.

Now, subdir-modorder lists them in a different order: core-y/m, libs-y/m,
drivers-y/m.

Presumably, there was no practical issue because the modules in drivers
and libs are orthogonal, but there is no reason to have this distortion.

Get back to the original order.

Fixes: b2c885549122 ("kbuild: update modules.order only when contained modules are updated")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Linux 6.0-rc1

Makefile: link with -z noexecstack --no-warn-rwx-segments

Users of GNU ld (BFD) from binutils 2.39+ will observe multiple
instances of a new warning when linking kernels in the form:

ld: warning: vmlinux: missing .note.GNU-stack section implies executable stack
ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
ld: warning: vmlinux has a LOAD segment with RWX permissions

Generally, we would like to avoid the stack being executable. Because
there could be a need for the stack to be executable, assembler sources
have to opt-in to this security feature via explicit creation of the
.note.GNU-stack feature (which compilers create by default) or command
line flag --noexecstack. Or we can simply tell the linker the
production of such sections is irrelevant and to link the stack as
--noexecstack.

LLVM's LLD linker defaults to -z noexecstack, so this flag isn't
strictly necessary when linking with LLD, only BFD, but it doesn't hurt
to be explicit here for all linkers IMO. --no-warn-rwx-segments is
currently BFD specific and only available in the current latest release,
so it's wrapped in an ld-option check.

While the kernel makes extensive usage of ELF sections, it doesn't use
permissions from ELF segments.

Link: https://lore.kernel.org/linux-block/3af4127a-f453-4cf7-f133-a181cce06f73@kernel.dk/
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107
Link: https://github.com/llvm/llvm-project/issues/57009
Reported-and-tested-by: Jens Axboe <axboe@kernel.dk>
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kbuild: add dtbs_prepare target

Factor out the common prerequisites for DT compilation into the new
target, dtbs_prepare.

Add comments to explain why include/config/kernel.release is the
prerequisite. Our policy is that installation targets must not rebuild
anything in the tree. If 'make modules_install' is executed as root,
include/config/kernel.release may be owned by root.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

kbuild: error out if $(KBUILD_EXTMOD) contains % or :

If the directory path given to KBUILD_EXTMOD (or M=) contains % or :,
the module fails to build.

% is used in pattern rules, and : as the separator of dependencies.

Bail out with a clearer error message.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

kbuild: drop support for CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3

The difference in most compilers between `-O3` and `-O2` is mostly down
to whether loops with statically determinable trip counts are fully
unrolled vs unrolled to a multiple of SIMD width.

This patch is effectively a revert of
commit 15f5db60a137 ("kbuild,arc: add
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC") without re-adding
ARCH_CFLAGS

Ever since
commit cfdbc2e16e65 ("ARC: Build system: Makefiles, Kconfig, Linker
script")
ARC has been built with -O3, though the reason for doing so was not
specified in inline comments or the commit message. This commit does not
re-add -O3 to arch/arc/Makefile.

Folks looking to experiment with `-O3` (or any compiler flag for that
matter) may pass them along to the command line invocation of make:

$ make KCFLAGS=-O3

Code that looks to re-add an explicit Kconfig option for `-O3` should
provide:
1. A rigorous and reproducible performance profile of a reasonable
userspace workload that demonstrates a hot loop in the kernel that
would benefit from `-O3` over `-O2`.
2. Disassembly of said loop body before and after.
3. Provides stats on terms of increase in file size.

Link: https://lore.kernel.org/linux-kbuild/CA+55aFz2sNBbZyg-_i8_Ldr2e8o9dfvdSfHHuRzVtP2VMAUWPg@mail.gmail.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Makefile: replace headers_install with headers for kselftest

Replace headers_install with headers as kselftest uses the header
files from within the kernel tree rather than from a system-wide
installation.

We can still run this directly:

$ make O=build kselftest-all

and when building from the selftests directory:

$ make O=build headers
$ make O=build -C tools/testing/selftests all

Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Reported-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

io_uring: move to separate directory

In preparation for splitting io_uring up a bit, move it into its own
top level directory. It didn't really belong in fs/ anyway, as it's
not a file system only API.

This adds io_uring/ and moves the core files in there, and updates the
MAINTAINERS file for the new location.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Makefile: add headers_install to kselftest targets

Add headers_install as a dependency to kselftest targets so that they
can be run directly from the top of the tree. The kselftest Makefile
used to try to call headers_install "backwards" but failed due to the
relative path not being consistent.

Now we can either run this directly:

$ make O=build kselftest-all

or this:

$ make O=build headers_install
$ make O=build -C tools/testing/selftest all

The same commands work as well when building directly in the source
tree (no O=) or any arbitrary path (relative or absolute).

Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Linux 5.19

Linux 5.19-rc8

Linux 5.19-rc7

Linux 5.19-rc6

Linux 5.19-rc5

Linux 5.19-rc4

kbuild: link vmlinux only once for CONFIG_TRIM_UNUSED_KSYMS (2nd attempt)

If CONFIG_TRIM_UNUSED_KSYMS is enabled and the kernel is built from
a pristine state, the vmlinux is linked twice.

Commit 3fdc7d3fe4c0 ("kbuild: link vmlinux only once for
CONFIG_TRIM_UNUSED_KSYMS") explains why this happens, but it did not fix
the issue at all.

Now I realized I had applied a wrong patch.

In v1 patch [1], the autoksyms_recursive target correctly recurses to
"$(MAKE) -f $(srctree)/Makefile autoksyms_recursive".

In v2 patch [2], I accidentally dropped the diff line, and it recurses to
"$(MAKE) -f $(srctree)/Makefile vmlinux".

Restore the code I intended in v1.

[1]: https://lore.kernel.org/linux-kbuild/1521045861-22418-8-git-send-email-yamada.masahiro@socionext.com/
[2]: https://lore.kernel.org/linux-kbuild/1521166725-24157-8-git-send-email-yamada.masahiro@socionext.com/

Fixes: 3fdc7d3fe4c0 ("kbuild: link vmlinux only once for CONFIG_TRIM_UNUSED_KSYMS")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

Linux 5.19-rc3

Linux 5.19-rc2

gcc-12: disable '-Warray-bounds' universally for now

In commit 8b202ee21839 ("s390: disable -Warray-bounds") the s390 people
disabled the '-Warray-bounds' warning for gcc-12, because the new logic
in gcc would cause warnings for their use of the S390_lowcore macro,
which accesses absolute pointers.

It turns out gcc-12 has many other issues in this area, so this takes
that s390 warning disable logic, and turns it into a kernel build config
entry instead.

Part of the intent is that we can make this all much more targeted, and
use this conflig flag to disable it in only particular configurations
that cause problems, with the s390 case as an example:

select GCC12_NO_ARRAY_BOUNDS

and we could do that for other configuration cases that cause issues.

Or we could possibly use the CONFIG_CC_NO_ARRAY_BOUNDS thing in a more
targeted way, and disable the warning only for particular uses: again
the s390 case as an example:

KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_CC_NO_ARRAY_BOUNDS),-Wno-array-bounds)

but this ends up just doing it globally in the top-level Makefile, since
the current issues are spread fairly widely all over:

KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds

We'll try to limit this later, since the gcc-12 problems are rare enough
that *much* of the kernel can be built with it without disabling this
warning.

Cc: Kees Cook <keescook@chromium.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gcc-12: disable '-Wdangling-pointer' warning for now

While the concept of checking for dangling pointers to local variables
at function exit is really interesting, the gcc-12 implementation is not
compatible with reality, and results in false positives.

For example, gcc sees us putting things on a local list head allocated
on the stack, which involves exactly those kinds of pointers to the
local stack entry:

In function ‘__list_add’,
inlined from ‘list_add_tail’ at include/linux/list.h:102:2,
inlined from ‘rebuild_snap_realms’ at fs/ceph/snap.c:434:2:
include/linux/list.h:74:19: warning: storing the address of local variable ‘realm_queue’ in ‘*&realm_27(D)->rebuild_item.prev’ [-Wdangling-pointer=]
74 | new->prev = prev;
| ~~~~~~~~~~^~~~~~

But then gcc - understandably - doesn't really understand the big
picture how the doubly linked list works, so doesn't see how we then end
up emptying said list head in a loop and the pointer we added has been
removed.

Gcc also complains about us (intentionally) using this as a way to store
a kind of fake stack trace, eg

drivers/acpi/acpica/utdebug.c:40:38: warning: storing the address of local variable ‘current_sp’ in ‘acpi_gbl_entry_stack_pointer’ [-Wdangling-pointer=]
40 | acpi_gbl_entry_stack_pointer = &current_sp;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~

which is entirely reasonable from a compiler standpoint, and we may want
to change those kinds of patterns, but not not.

So this is one of those "it would be lovely if the compiler were to
complain about us leaving dangling pointers to the stack", but not this
way.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linux 5.19-rc1

kbuild: clean .tmp_* pattern by make clean

Change the "make clean" rule to remove all the .tmp_* files.

.tmp_objdiff is the only exception, which should be removed by
"make mrproper".

Rename the record directory of objdiff, .tmp_objdiff to .objdiff to
avoid the removal by "make clean".

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)

kbuild: factor out the common installation code into scripts/install.sh

Many architectures have similar install.sh scripts.

The first half is really generic; it verifies that the kernel image
and System.map exist, then executes ~/bin/${INSTALLKERNEL} or
/sbin/${INSTALLKERNEL} if available.

The second half is kind of arch-specific; it copies the kernel image
and System.map to the destination, but the code is slightly different.

Factor out the generic part into scripts/install.sh.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

Makefile: fix 2 typos

Fix typos in comments so that they make sense.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: support W=e to make build abort in case of warning

When developing new code/feature, CONFIG_WERROR is most
often turned off, especially for people using make W=12 to
get more warnings.

In such case, turning on -Werror temporarily would require
switching on CONFIG_WERROR in the configuration, building,
then switching off CONFIG_WERROR.

For this use case, this patch introduces a new 'e' modifier
to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
got added to the kernel (built-in) and modules' CFLAGS.

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: make *.mod not depend on *.o

The dependency

$(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o

... exists because *.mod files previously contained undefined symbols,
which are computed from *.o files when CONFIG_TRIM_UNUSED_KSYMS=y.

Now that the undefined symbols are put into separate *.usyms files,
there is no reason to make *.mod depend on *.o files.

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

kbuild: split the second line of *.mod into *.usyms

The *.mod files have two lines; the first line lists the member objects
of the module, and the second line, if CONFIG_TRIM_UNUSED_KSYMS=y, lists
the undefined symbols.

Currently, we generate *.mod after constructing composite modules,
otherwise, we cannot compute the second line. No prerequisite is
required to print the first line.

They are orthogonal. Splitting them into separate commands will ease
further cleanups.

This commit splits the list of undefined symbols out to *.usyms files.

Previously, the list of undefined symbols ended up with a very long
line, but now it has one symbol per line.

Use sed like we did before commit 7d32358be8ac ("kbuild: avoid split
lines in .mod files").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: Allow kernel installation packaging to override pkg-config

Add HOSTPKG_CONFIG to allow tooling that builds the kernel to override
what pkg-config and parameters are used.

Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

randstruct: Split randstruct Makefile and CFLAGS

To enable the new Clang randstruct implementation[1], move
randstruct into its own Makefile and split the CFLAGS from
GCC_PLUGINS_CFLAGS into RANDSTRUCT_CFLAGS.

[1] https://reviews.llvm.org/D121556

Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220503205503.3054173-5-keescook@chromium.org

objtool: Add CONFIG_OBJTOOL

Now that stack validation is an optional feature of objtool, add
CONFIG_OBJTOOL and replace most usages of CONFIG_STACK_VALIDATION with
it.

CONFIG_STACK_VALIDATION can now be considered to be frame-pointer
specific. CONFIG_UNWINDER_ORC is already inherently valid for live
patching, so no need to "validate" it.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/939bf3d85604b2a126412bf11af6e3bd3b872bcb.1650300597.git.jpoimboe@redhat.com

Linux 5.18

Linux 5.18-rc7

Linux 5.18-rc6

Linux 5.18-rc5

Linux 5.18-rc4

Linux 5.18-rc3

Linux 5.18-rc2

Linux 5.18-rc1

kbuild: Remove '-mno-global-merge'

This flag is specific to clang, where it is only used by the 32-bit and
64-bit ARM backends. In certain situations, the presence of this flag
will cause a warning, as shown by commit 6580c5c18fb3 ("um: clang: Strip
out -mno-global-merge from USER_CFLAGS").

Since commit 61163efae020 ("kbuild: LLVMLinux: Add Kbuild support for
building kernel with Clang") that added this flag back in 2014, there
have been quite a few changes to the GlobalMerge pass in LLVM. Building
several different ARCH=arm and ARCH=arm64 configurations with LLVM 11
(minimum) and 15 (current main version) with this flag removed (i.e.,
with the default of '-mglobal-merge') reveals no modpost warnings, so it
is likely that the issue noted in the comment is no longer relevant due
to changes in LLVM or modpost, meaning this flag can be removed.

If any new warnings show up that are a result of the removal of this
flag, it can be added back under arch/arm{,64}/Makefile to avoid
warnings on other architectures.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: Make $(LLVM) more flexible

The LLVM make variable allows a developer to quickly switch between the
GNU and LLVM tools. However, it does not handle versioned binaries, such
as the ones shipped by Debian, as LLVM=1 just defines the tool variables
with the unversioned binaries.

There was some discussion during the review of the patch that introduces
LLVM=1 around versioned binaries, ultimately coming to the conclusion
that developers can just add the folder that contains the unversioned
binaries to their PATH, as Debian's versioned suffixed binaries are
really just symlinks to the unversioned binaries in /usr/lib/llvm-#/bin:

$ realpath /usr/bin/clang-14
/usr/lib/llvm-14/bin/clang

$ PATH=/usr/lib/llvm-14/bin:$PATH make ... LLVM=1

However, that can be cumbersome to developers who are constantly testing
series with different toolchains and versions. It is simple enough to
support these versioned binaries directly in the Kbuild system by
allowing the developer to specify the version suffix with LLVM=, which
is shorter than the above suggestion:

$ make ... LLVM=-14

It does not change the meaning of LLVM=1 (which will continue to use
unversioned binaries) and it does not add too much additional complexity
to the existing $(LLVM) code, while allowing developers to quickly test
their series with different versions of the whole LLVM suite of tools.

Some developers may build LLVM from source but not add the binaries to
their PATH, as they may not want to use that toolchain systemwide.
Support those developers by allowing them to supply the directory that
the LLVM tools are available in, as it is no more complex to support
than the version suffix change above.

$ make ... LLVM=/path/to/llvm/

Update and reorder the documentation to reflect these new additions.
At the same time, notate that LLVM=0 is not the same as just omitting it
altogether, which has confused people in the past.

Link: https://lore.kernel.org/r/20200317215515.226917-1-ndesaulniers@google.com/
Link: https://lore.kernel.org/r/20220224151322.072632223@infradead.org/
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kbuild: replace $(if A,A,B) with $(or A,B)

$(or ...) is available since GNU Make 3.81, and useful to shorten the
code in some places.

Covert as follows:

$(if A,A,B) --> $(or A,B)

This patch also converts:

$(if A, A, B) --> $(or A, B)

Strictly speaking, the latter is not an equivalent conversion because
GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B)
expands to " A", while $(or A, B) expands to "A".

Anyway, preceding spaces are not significant in the code hunks I touched.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

kbuild: Add environment variables for userprogs flags

Allow additional arguments be passed to userprogs compilation.
Reproducible clang builds need to provide a sysroot and gcc path to
ensure the same toolchain is used across hosts. KCFLAGS is not currently
used for any user programs compilation, so add new USERCFLAGS and
USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.

Clang might detect GCC installation on hosts which have it installed
to a default location in /. With addition of these environment
variables, you can specify flags such as:

$ make USERCFLAGS=--sysroot=/path/to/sysroot

This can also be used to specify different sysroots such as musl or
bionic which may be installed on the host in paths that the compiler
may not search by default.

Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Makefile: Enable -Wzero-length-bounds

With all known internal zero-length accesses fixed, it is possible to
enable -Wzero-length-bounds globally. Since this is included by default
in -Warray-bounds, we just need to stop disabling it.

Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAKwvOd=bcs5W6eEDXGn5ROR2EuMiSp_2e6sLFxak=KK6yLWcvA@mail.gmail.com

Makefile: Enable -Warray-bounds

With the recent fixes for flexible arrays and expanded FORTIFY_SOURCE
coverage, it is now possible to enable -Warray-bounds. Since both GCC
and Clang include -Warray-bounds in -Wall, adjust the Makefile to just
stop disabling it.

Note that this option can be conservative in its warnings (which is
done at casting time rather than access time), but this is reasonable
since the cast variables may be accessed out of a scope where the true
size of the original object can't be evaluated. These handful of false
positives (which are arguably bad casts and can be easily avoided),
are worth dealing with because of the many places where this option
has helped identify missed bounds checks and even accesses done against
cases where a NULL pointer could be reached.

https://github.com/KSPP/linux/issues/109
https://github.com/KSPP/linux/issues/151

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org
Co-developed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

Kbuild: use -std=gnu11 for KBUILD_USERCFLAGS

As we change the C language standard for the kernel from gnu89 to
gnu11, it makes sense to also update the version for user space
compilation.

Some users have older native compilers than what they use for
kernel builds, so I considered using gnu99 as the default version
for wider compatibility with gcc-4.6 and earlier.

However, testing with older compilers showed that we already require
HOSTCC version 5.1 as well because a lot of host tools include
linux/compiler.h that uses __has_attribute():

CC tools/objtool/exec-cmd.o
In file included from tools/include/linux/compiler_types.h:36:0,
from tools/include/linux/compiler.h:5,
from exec-cmd.c:2:
tools/include/linux/compiler-gcc.h:19:5: error: "__has_attribute" is not defined [-Werror=undef]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Kbuild: move to -std=gnu11

During a patch discussion, Linus brought up the option of changing
the C standard version from gnu89 to gnu99, which allows using variable
declaration inside of a for() loop. While the C99, C11 and later standards
introduce many other features, most of these are already available in
gnu89 as GNU extensions as well.

An earlier attempt to do this when gcc-5 started defaulting to
-std=gnu11 failed because at the time that caused warnings about
designated initializers with older compilers. Now that gcc-5.1 is
the minimum compiler version used for building kernels, that is no
longer a concern. Similarly, the behavior of 'inline' functions changes
between gnu89 using gnu_inline behavior and gnu11 using standard c99+
behavior, but this was taken care of by defining 'inline' to include
__attribute__((gnu_inline)) in order to allow building with clang a
while ago.

Nathan Chancellor reported a new -Wdeclaration-after-statement
warning that appears in a system header on arm, this still needs a
workaround.

The differences between gnu99, gnu11, gnu1x and gnu17 are fairly
minimal and mainly impact warnings at the -Wpedantic level that the
kernel never enables. Between these, gnu11 is the newest version
that is supported by all supported compiler versions, though it is
only the default on gcc-5, while all other supported versions of
gcc or clang default to gnu1x/gnu17.

Link: https://lore.kernel.org/lkml/CAHk-=wiyCH7xeHcmiFJ-YgXUy2Jaj7pnkdKpcovt8fYbVFW3TA@mail.gmail.com/
Link: https://github.com/ClangBuiltLinux/linux/issues/1603
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: David Sterba <dsterba@suse.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Kbuild: use -Wdeclaration-after-statement

The kernel is moving from using `-std=gnu89` to `-std=gnu11`, permitting
the use of additional C11 features such as for-loop initial declarations.

One contentious aspect of C99 is that it permits mixed declarations and
code, and for now at least, it seems preferable to enforce that
declarations must come first.

These warnings were already enabled in the kernel itself, but not
for KBUILD_USERCFLAGS or the compat VDSO on arch/arm64, which uses
a separate set of CFLAGS.

This patch fixes an existing violation in modpost.c, which is not
reported because of the missing flag in KBUILD_USERCFLAGS:

| scripts/mod/modpost.c: In function ‘match’:
| scripts/mod/modpost.c:837:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
| 837 | const char *endp = p + strlen(p) - 1;
| | ^~~~~

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[arnd: don't add a duplicate flag to the default set, update changelog]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 (x86-64)
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Linux 5.17

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linux 5.17-rc8

Linux 5.17-rc7

Linux 5.17-rc6

Linux 5.17-rc5

Linux 5.17-rc4

Linux 5.17-rc3

Linux 5.17-rc2

Linux 5.17-rc1

Revert "Makefile: Do not quote value for CONFIG_CC_IMPLICIT_FALLTHROUGH"

This reverts commit cd8c917a56f20f48748dd43d9ae3caff51d5b987.

Commit 129ab0d2d9f3 ("kbuild: do not quote string values in
include/config/auto.conf") provided the final solution.

Now reverting the temporary workaround.

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

kbuild: do not quote string values in include/config/auto.conf

The previous commit fixed up all shell scripts to not include
include/config/auto.conf.

Now that include/config/auto.conf is only included by Makefiles,
we can change it into a more Make-friendly form.

Previously, Kconfig output string values enclosed with double-quotes
(both in the .config and include/config/auto.conf):

CONFIG_X="foo bar"

Unlike shell, Make handles double-quotes (and single-quotes as well)
verbatim. We must rip them off when used.

There are some patterns:

[1] $(patsubst "%",%,$(CONFIG_X))
[2] $(CONFIG_X:"%"=%)
[3] $(subst ",,$(CONFIG_X))
[4] $(shell echo $(CONFIG_X))

These are not only ugly, but also fragile.

[1] and [2] do not work if the value contains spaces, like
CONFIG_X=" foo bar "

[3] does not work correctly if the value contains double-quotes like
CONFIG_X="foo\"bar"

[4] seems to work better, but has a cost of forking a process.

Anyway, quoted strings were always PITA for our Makefiles.

This commit changes Kconfig to stop quoting in include/config/auto.conf.

These are the string type symbols referenced in Makefiles or scripts:

ACPI_CUSTOM_DSDT_FILE
ARC_BUILTIN_DTB_NAME
ARC_TUNE_MCPU
BUILTIN_DTB_SOURCE
CC_IMPLICIT_FALLTHROUGH
CC_VERSION_TEXT
CFG80211_EXTRA_REGDB_KEYDIR
EXTRA_FIRMWARE
EXTRA_FIRMWARE_DIR
EXTRA_TARGETS
H8300_BUILTIN_DTB
INITRAMFS_SOURCE
LOCALVERSION
MODULE_SIG_HASH
MODULE_SIG_KEY
NDS32_BUILTIN_DTB
NIOS2_DTB_SOURCE
OPENRISC_BUILTIN_DTB
SOC_CANAAN_K210_DTB_SOURCE
SYSTEM_BLACKLIST_HASH_LIST
SYSTEM_REVOCATION_KEYS
SYSTEM_TRUSTED_KEYS
TARGET_CPU
UNUSED_KSYMS_WHITELIST
XILINX_MICROBLAZE0_FAMILY
XILINX_MICROBLAZE0_HW_VER
XTENSA_VARIANT_NAME

I checked them one by one, and fixed up the code where necessary.

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

certs: refactor file cleaning

'make clean' removes files listed in 'targets'. It is redundant to
specify both 'targets' and 'clean-files'.

Move 'targets' assignments out of the ifeq-conditionals so
scripts/Makefile.clean can see them.

One effective change is that certs/certs/signing_key.x509 is now
deleted by 'make clean' instead of 'make mrproper. This certificate
is embedded in the kernel. It is not used in any way by external
module builds.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

kbuild: remove headers_check stub

Linux 5.15 is out. Remove this stub now.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

x86: Move RETPOLINE*_CFLAGS to arch Makefile

Currently, RETPOLINE*_CFLAGS are defined in the top-level Makefile
but only x86 makes use of them. Move them there. If ever another
architecture finds the need, it can be reconsidered.

[ bp: Massage a bit. ]

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lkml.kernel.org/r/20211119165630.219152765@infradead.org

Makefile: Enable -Wcast-function-type

In order to make sure new function cast mismatches are not introduced
in the kernel (to avoid tripping CFI checking), the kernel should be
globally built with -Wcast-function-type.

Link: https://github.com/KSPP/linux/issues/20
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Linux 5.16

Linux 5.16-rc8

Linux 5.16-rc7

Linux 5.16-rc6

Linux 5.16-rc5

Revert "kbuild: Enable DT schema checks for %.dtb targets"

This reverts commit 53182e81f47d4ea0c727c49ad23cb782173ab849.

This added tool dependencies on various build systems using %.dtb
targets. Validation will need to be controlled by a kconfig or make
variable instead, but for now let's just revert it.

Signed-off-by: Rob Herring <robh@kernel.org>

Makefile: Do not quote value for CONFIG_CC_IMPLICIT_FALLTHROUGH

Andreas reported that a specific build environment for an external
module, being a bit broken, does pass CC_IMPLICIT_FALLTHROUGH quoted as
argument to gcc, causing an error

gcc-11: error: "-Wimplicit-fallthrough=5": linker input file not found: No such file or directory

Until this is more generally fixed as outlined in [1], by fixing
scripts/link-vmlinux.sh, scripts/gen_autoksyms.sh, etc to not directly
include the include/config/auto.conf, and in a second step, change
Kconfig to generate the auto.conf without "", workaround the issue by
explicitly unquoting CC_IMPLICIT_FALLTHROUGH.

Reported-by: Andreas Beckmann <anbe@debian.org>
Link: https://bugs.debian.org/1001083
Link: https://lore.kernel.org/linux-kbuild/CAK7LNAR-VXwHFEJqCcrFDZj+_4+Xd6oynbj_0eS8N504_ydmyw@mail.gmail.com/ [1]
Signed-off-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linux 5.16-rc4

Linux 5.16-rc3

Merge tag 'drm-fixes-2021-11-26' of git://anongit.freedesktop.org/drm/drm

Pull drm fixes from Dave Airlie:
"No idea if turkey comes before pull request processing, but here's the
regular week's fixes. A bunch for amdgpu, nouveau adds support for a
new GPU (like a PCI ID addition), and a scattering of fixes across
i915/hyperv/aspeed/vc4.

Specifics:

amdgpu:
- SRIOV fixes
- dma-buf double free fix
- Display fixes for GPU resets
- Fix DSC powergating regression
- GPU TSC fixes
- Interrupt handler overflow fixes
- Endian fix in IP discovery table handling
- Aldebaran ASPM fix
- Fix overclocking regression on older asics
- Backlight/ACPI fix

amdkfd:
- SVM fixes
- VMA removal race fix

hyperv:
- removal fix

aspeed:
- vga_pw sysfs file fix

vc4:
- error checking fix

nouveau:
- support GA106
- fix a few error checks

i915:
- fix wakeref handling around PXP suspend"

* tag 'drm-fixes-2021-11-26' of git://anongit.freedesktop.org/drm/drm: (25 commits)
drm/amd/display: update bios scratch when setting backlight
drm/amdgpu/pm: fix powerplay OD interface
drm/amdgpu: Skip ASPM programming on aldebaran
drm/amdgpu: fix byteorder error in amdgpu discovery
drm/amdgpu: enable Navi retry fault wptr overflow
drm/amdgpu: enable Navi 48-bit IH timestamp counter
drm/amdkfd: simplify drain retry fault
drm/amdkfd: handle VMA remove race
drm/amdkfd: process exit and retry fault race
drm/amdgpu: IH process reset count when restart
drm/amdgpu/gfx9: switch to golden tsc registers for renoir+
drm/amdgpu/gfx10: add wraparound gpu counter check for APUs as well
drm/amdgpu: move kfd post_reset out of reset_sriov function
drm/amd/display: Fixed DSC would not PG after removing DSC stream
drm/amd/display: Reset link encoder assignments for GPU reset
drm/amd/display: Set plane update flags for all planes in reset
drm/amd/display: Fix DPIA outbox timeout after GPU reset
drm/amdgpu: Fix double free of dmabuf
drm/amdgpu: Fix MMIO HDP flush on SRIOV
drm/i915/gt: Hold RPM wakelock during PXP suspend
...

Linux 5.16-rc2

Linux 5.16-rc1

kconfig: Add support for -Wimplicit-fallthrough

Add Kconfig support for -Wimplicit-fallthrough for both GCC and Clang.

The compiler option is under configuration CC_IMPLICIT_FALLTHROUGH,
which is enabled by default.

Special thanks to Nathan Chancellor who fixed the Clang bug[1][2]. This
bugfix only appears in Clang 14.0.0, so older versions still contain
the bug and -Wimplicit-fallthrough won't be enabled for them, for now.

This concludes a long journey and now we are finally getting rid
of the unintentional fallthrough bug-class in the kernel, entirely. :)

Link: https://github.com/llvm/llvm-project/commit/9ed4a94d6451046a51ef393cd62f00710820a7e8 [1]
Link: https://bugs.llvm.org/show_bug.cgi?id=51094 [2]
Link: https://github.com/KSPP/linux/issues/115
Link: https://github.com/ClangBuiltLinux/linux/issues/236
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

- Remove the global -isystem compiler flag, which was made possible by
the introduction of <linux/stdarg.h>

- Improve the Kconfig help to print the location in the top menu level

- Fix "FORCE prerequisite is missing" build warning for sparc

- Add new build targets, tarzst-pkg and perf-tarzst-src-pkg, which
generate a zstd-compressed tarball

- Prevent gen_init_cpio tool from generating a corrupted cpio when
KBUILD_BUILD_TIMESTAMP is set to 2106-02-07 or later

- Misc cleanups

* tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
kbuild: use more subdir- for visiting subdirectories while cleaning
sh: remove meaningless archclean line
initramfs: Check timestamp to prevent broken cpio archive
kbuild: split DEBUG_CFLAGS out to scripts/Makefile.debug
gen_init_cpio: add static const qualifiers
kbuild: Add make tarzst-pkg build option
scripts: update the comments of kallsyms support
sparc: Add missing "FORCE" target when using if_changed
kconfig: refactor conf_touch_dep()
kconfig: refactor conf_write_dep()
kconfig: refactor conf_write_autoconf()
kconfig: add conf_get_autoheader_name()
kconfig: move sym_escape_string_value() to confdata.c
kconfig: refactor listnewconfig code
kconfig: refactor conf_write_symbol()
kconfig: refactor conf_write_heading()
kconfig: remove 'const' from the return type of sym_escape_string_value()
kconfig: rename a variable in the lexer to a clearer name
kconfig: narrow the scope of variables in the lexer
kconfig: Create links to main menu items in search
...

Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
"257 patches.

Subsystems affected by this patch series: scripts, ocfs2, vfs, and
mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
cleanups, kfence, and damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
mm/damon: remove return value from before_terminate callback
mm/damon: fix a few spelling mistakes in comments and a pr_debug message
mm/damon: simplify stop mechanism
Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
Docs/admin-guide/mm/damon/start: simplify the content
Docs/admin-guide/mm/damon/start: fix a wrong link
Docs/admin-guide/mm/damon/start: fix wrong example commands
mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
mm/damon: remove unnecessary variable initialization
Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
selftests/damon: support watermarks
mm/damon/dbgfs: support watermarks
mm/damon/schemes: activate schemes based on a watermarks mechanism
tools/selftests/damon: update for regions prioritization of schemes
mm/damon/dbgfs: support prioritization weights
mm/damon/vaddr,paddr: support pageout prioritization
mm/damon/schemes: prioritize regions within the quotas
mm/damon/selftests: support schemes quotas
mm/damon/dbgfs: support quotas of schemes
...

Compiler Attributes: add __alloc_size() for better bounds checking

GCC and Clang can use the "alloc_size" attribute to better inform the
results of __builtin_object_size() (for compile-time constant values).
Clang can additionally use alloc_size to inform the results of
__builtin_dynamic_object_size() (for run-time values).

Because GCC sees the frequent use of struct_size() as an allocator size
argument, and notices it can return SIZE_MAX (the overflow indication),
it complains about these call sites overflowing (since SIZE_MAX is
greater than the default -Walloc-size-larger-than=PTRDIFF_MAX). This
isn't helpful since we already know a SIZE_MAX will be caught at
run-time (this was an intentional design). To deal with this, we must
disable this check as it is both a false positive and redundant. (Clang
does not have this warning option.)

Unfortunately, just checking the -Wno-alloc-size-larger-than is not
sufficient to make the __alloc_size attribute behave correctly under
older GCC versions. The attribute itself must be disabled in those
situations too, as there appears to be no way to reliably silence the
SIZE_MAX constant expression cases for GCC versions less than 9.1:

In file included from ./include/linux/resource_ext.h:11,
from ./include/linux/pci.h:40,
from drivers/net/ethernet/intel/ixgbe/ixgbe.h:9,
from drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c:4:
In function 'kmalloc_node',
inlined from 'ixgbe_alloc_q_vector' at ./include/linux/slab.h:743:9:
./include/linux/slab.h:618:9: error: argument 1 value '18446744073709551615' exceeds maximum object size 9223372036854775807 [-Werror=alloc-size-larger-than=]
return __kmalloc_node(size, flags, node);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/slab.h: In function 'ixgbe_alloc_q_vector':
./include/linux/slab.h:455:7: note: in a call to allocation function '__kmalloc_node' declared here
void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_slab_alignment __malloc;
^~~~~~~~~~~~~~

Specifically:
'-Wno-alloc-size-larger-than' is not correctly handled by GCC < 9.1
https://godbolt.org/z/hqsfG7q84 (doesn't disable)
https://godbolt.org/z/P9jdrPTYh (doesn't admit to not knowing about option)
https://godbolt.org/z/465TPMWKb (only warns when other warnings appear)

'-Walloc-size-larger-than=18446744073709551615' is not handled by GCC < 8.2
https://godbolt.org/z/73hh1EPxz (ignores numeric value)

Since anything marked with __alloc_size would also qualify for marking
with __malloc, just include __malloc along with it to avoid redundant
markings. (Suggested by Linus Torvalds.)

Finally, make sure checkpatch.pl doesn't get confused about finding the
__alloc_size attribute on functions. (Thanks to Joe Perches.)

Link: https://lkml.kernel.org/r/20210930222704.2631604-3-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jing Xiangfeng <jingxiangfeng@huawei.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'devicetree-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree updates from Rob Herring:

- Convert /reserved-memory bindings to schemas

- Convert a bunch of NFC bindings to schemas

- Convert bindings to schema: Xilinx USB, Freescale DDR controller, Arm
CCI-400, UBlox Neo-6M, 1-Wire GPIO, MSI controller, ASpeed LPC, OMAP
and Inside-Secure HWRNG, register-bit-led, OV5640, Silead GSL1680,
Elan ekth3000, Marvell bluetooth, TI wlcore, TI bluetooth, ESP
ESP8089, tlm,trusted-foundations, Microchip cap11xx, Ralink SoCs and
boards, and TI sysc

- New binding schemas for: msi-ranges, Aspeed UART routing controller,
palmbus, Xylon LogiCVC display controller, Mediatek's MT7621 SDRAM
memory controller, and Apple M1 PCIe host

- Run schema checks for %.dtb targets

- Improve build time when using DT_SCHEMA_FILES

- Improve error message when dtschema is not found

- Various doc reference fixes in MAINTAINERS

- Convert architectures to common CPU h/w ID parsing function
of_get_cpu_hwid().

- Allow for empty NUMA node IDs which may be hotplugged

- Cleanup of __fdt_scan_reserved_mem()

- Constify device_node parameters

- Update dtc to upstream v1.6.1-19-g0a3a9d3449c8. Adds new checks
'node_name_vs_property_name' and 'interrupt_map'.

- Enable dtc 'unit_address_format' warning by default

- Fix unittest EXPECT text for gpio hog errors

* tag 'devicetree-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (97 commits)
dt-bindings: net: ti,bluetooth: Document default max-speed
dt-bindings: pci: rcar-pci-ep: Document r8a7795
dt-bindings: net: qcom,ipa: IPA does support up to two iommus
of/fdt: Remove of_scan_flat_dt() usage for __fdt_scan_reserved_mem()
of: unittest: document intentional interrupt-map provider build warning
of: unittest: fix EXPECT text for gpio hog errors
of/unittest: Disable new dtc node_name_vs_property_name and interrupt_map warnings
scripts/dtc: Update to upstream version v1.6.1-19-g0a3a9d3449c8
dt-bindings: arm: firmware: tlm,trusted-foundations: Convert txt bindings to yaml
dt-bindings: display: tilcd: Fix endpoint addressing in example
dt-bindings: input: microchip,cap11xx: Convert txt bindings to yaml
dt-bindings: ufs: exynos-ufs: add exynosautov9 compatible
dt-bindings: ufs: exynos-ufs: add io-coherency property
dt-bindings: mips: convert Ralink SoCs and boards to schema
dt-bindings: display: xilinx: Fix example with psgtr
dt-bindings: net: nfc: nxp,pn544: Convert txt bindings to yaml
dt-bindings: Add a help message when dtschema tools are missing
dt-bindings: bus: ti-sysc: Update to use yaml binding
dt-bindings: sram: Allow numbers in sram region node name
dt-bindings: display: Document the Xylon LogiCVC display controller
...

Merge tag 'net-next-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
"Core:

- Remove socket skb caches

- Add a SO_RESERVE_MEM socket op to forward allocate buffer space and
avoid memory accounting overhead on each message sent

- Introduce managed neighbor entries - added by control plane and
resolved by the kernel for use in acceleration paths (BPF / XDP
right now, HW offload users will benefit as well)

- Make neighbor eviction on link down controllable by userspace to
work around WiFi networks with bad roaming implementations

- vrf: Rework interaction with netfilter/conntrack

- fq_codel: implement L4S style ce_threshold_ect1 marking

- sch: Eliminate unnecessary RCU waits in mini_qdisc_pair_swap()

BPF:

- Add support for new btf kind BTF_KIND_TAG, arbitrary type tagging
as implemented in LLVM14

- Introduce bpf_get_branch_snapshot() to capture Last Branch Records

- Implement variadic trace_printk helper

- Add a new Bloomfilter map type

- Track <8-byte scalar spill and refill

- Access hw timestamp through BPF's __sk_buff

- Disallow unprivileged BPF by default

- Document BPF licensing

Netfilter:

- Introduce egress hook for looking at raw outgoing packets

- Allow matching on and modifying inner headers / payload data

- Add NFT_META_IFTYPE to match on the interface type either from
ingress or egress

Protocols:

- Multi-Path TCP:
- increase default max additional subflows to 2
- rework forward memory allocation
- add getsockopts: MPTCP_INFO, MPTCP_TCPINFO, MPTCP_SUBFLOW_ADDRS

- MCTP flow support allowing lower layer drivers to configure msg
muxing as needed

- Automatic Multicast Tunneling (AMT) driver based on RFC7450

- HSR support the redbox supervision frames (IEC-62439-3:2018)

- Support for the ip6ip6 encapsulation of IOAM

- Netlink interface for CAN-FD's Transmitter Delay Compensation

- Support SMC-Rv2 eliminating the current same-subnet restriction, by
exploiting the UDP encapsulation feature of RoCE adapters

- TLS: add SM4 GCM/CCM crypto support

- Bluetooth: initial support for link quality and audio/codec offload

Driver APIs:

- Add a batched interface for RX buffer allocation in AF_XDP buffer
pool

- ethtool: Add ability to control transceiver modules' power mode

- phy: Introduce supported interfaces bitmap to express MAC
capabilities and simplify PHY code

- Drop rtnl_lock from DSA .port_fdb_{add,del} callbacks

New drivers:

- WiFi driver for Realtek 8852AE 802.11ax devices (rtw89)

- Ethernet driver for ASIX AX88796C SPI device (x88796c)

Drivers:

- Broadcom PHYs
- support 72165, 7712 16nm PHYs
- support IDDQ-SR for additional power savings

- PHY support for QCA8081, QCA9561 PHYs

- NXP DPAA2: support for IRQ coalescing

- NXP Ethernet (enetc): support for software TCP segmentation

- Renesas Ethernet (ravb) - support DMAC and EMAC blocks of
Gigabit-capable IP found on RZ/G2L SoC

- Intel 100G Ethernet
- support for eswitch offload of TC/OvS flow API, including
offload of GRE, VxLAN, Geneve tunneling
- support application device queues - ability to assign Rx and Tx
queues to application threads
- PTP and PPS (pulse-per-second) extensions

- Broadcom Ethernet (bnxt)
- devlink health reporting and device reload extensions

- Mellanox Ethernet (mlx5)
- offload macvlan interfaces
- support HW offload of TC rules involving OVS internal ports
- support HW-GRO and header/data split
- support application device queues

- Marvell OcteonTx2:
- add XDP support for PF
- add PTP support for VF

- Qualcomm Ethernet switch (qca8k): support for QCA8328

- Realtek Ethernet DSA switch (rtl8366rb)
- support bridge offload
- support STP, fast aging, disabling address learning
- support for Realtek RTL8365MB-VC, a 4+1 port 10M/100M/1GE switch

- Mellanox Ethernet/IB switch (mlxsw)
- multi-level qdisc hierarchy offload (e.g. RED, prio and shaping)
- offload root TBF qdisc as port shaper
- support multiple routing interface MAC address prefixes
- support for IP-in-IP with IPv6 underlay

- MediaTek WiFi (mt76)
- mt7921 - ASPM, 6GHz, SDIO and testmode support
- mt7915 - LED and TWT support

- Qualcomm WiFi (ath11k)
- include channel rx and tx time in survey dump statistics
- support for 80P80 and 160 MHz bandwidths
- support channel 2 in 6 GHz band
- spectral scan support for QCN9074
- support for rx decapsulation offload (data frames in 802.3
format)

- Qualcomm phone SoC WiFi (wcn36xx)
- enable Idle Mode Power Save (IMPS) to reduce power consumption
during idle

- Bluetooth driver support for MediaTek MT7922 and MT7921

- Enable support for AOSP Bluetooth extension in Qualcomm WCN399x and
Realtek 8822C/8852A

- Microsoft vNIC driver (mana)
- support hibernation and kexec

- Google vNIC driver (gve)
- support for jumbo frames
- implement Rx page reuse

Refactor:

- Make all writes to netdev->dev_addr go thru helpers, so that we can
add this address to the address rbtree and handle the updates

- Various TCP cleanups and optimizations including improvements to
CPU cache use

- Simplify the gnet_stats, Qdisc stats' handling and remove
qdisc->running sequence counter

- Driver changes and API updates to address devlink locking
deficiencies"

* tag 'net-next-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2122 commits)
Revert "net: avoid double accounting for pure zerocopy skbs"
selftests: net: add arp_ndisc_evict_nocarrier
net: ndisc: introduce ndisc_evict_nocarrier sysctl parameter
net: arp: introduce arp_evict_nocarrier sysctl parameter
libbpf: Deprecate AF_XDP support
kbuild: Unify options for BTF generation for vmlinux and modules
selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
net: vmxnet3: remove multiple false checks in vmxnet3_ethtool.c
net: avoid double accounting for pure zerocopy skbs
tcp: rename sk_wmem_free_skb
netdevsim: fix uninit value in nsim_drv_configure_vfs()
selftests/bpf: Fix also no-alu32 strobemeta selftest
bpf: Add missing map_delete_elem method to bloom filter map
selftests/bpf: Add bloom map success test for userspace calls
bpf: Add alignment padding for "map_extra" + consolidate holes
bpf: Bloom filter map naming fixups
selftests/bpf: Add test cases for struct_ops prog
bpf: Add dummy BPF STRUCT_OPS for test purpose
...

Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-11-01

We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).

The main changes are:

1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.

2) Parallelize bpf test_progs, from Yucong and Andrii.

3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.

4) Improve bpf selftests on s390, from Ilya.

5) bloomfilter bpf map type, from Joanne.

6) Big improvements to JIT tests especially on Mips, from Johan.

7) Support kernel module function calls from bpf, from Kumar.

8) Support typeless and weak ksym in light skeleton, from Kumar.

9) Disallow unprivileged bpf by default, from Pawan.

10) BTF_KIND_DECL_TAG support, from Yonghong.

11) Various bpftool cleanups, from Quentin.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits)
libbpf: Deprecate AF_XDP support
kbuild: Unify options for BTF generation for vmlinux and modules
selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
selftests/bpf: Fix also no-alu32 strobemeta selftest
bpf: Add missing map_delete_elem method to bloom filter map
selftests/bpf: Add bloom map success test for userspace calls
bpf: Add alignment padding for "map_extra" + consolidate holes
bpf: Bloom filter map naming fixups
selftests/bpf: Add test cases for struct_ops prog
bpf: Add dummy BPF STRUCT_OPS for test purpose
bpf: Factor out helpers for ctx access checking
bpf: Factor out a helper to prepare trampoline for struct_ops prog
selftests, bpf: Fix broken riscv build
riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
tools, build: Add RISC-V to HOSTARCH parsing
riscv, bpf: Increase the maximum number of iterations
selftests, bpf: Add one test for sockmap with strparser
selftests, bpf: Fix test_txmsg_ingress_parser error
...
====================

Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

kbuild: Unify options for BTF generation for vmlinux and modules

Using new PAHOLE_FLAGS variable to pass extra arguments to
pahole for both vmlinux and modules BTF data generation.

Adding new scripts/pahole-flags.sh script that detect and
prints pahole options.

[ fixed issues found by kernel test robot ]

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211029125729.70002-1-jolsa@kernel.org

Merge tag 'hardening-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull compiler hardening updates from Kees Cook:
"These are various compiler-related hardening feature updates. Notable
is the addition of an explicit limited rationale for, and deprecation
schedule of, gcc-plugins.

gcc-plugins:
- remove support for GCC 4.9 and older (Ard Biesheuvel)
- remove duplicate include in gcc-common.h (Ye Guojin)
- Explicitly document purpose and deprecation schedule (Kees Cook)
- Remove cyc_complexity (Kees Cook)

instrumentation:
- Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO (Kees Cook)

Clang LTO:
- kallsyms: strip LTO suffixes from static functions (Nick Desaulniers)"

* tag 'hardening-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
gcc-plugins: remove duplicate include in gcc-common.h
gcc-plugins: Remove cyc_complexity
gcc-plugins: Explicitly document purpose and deprecation schedule
kallsyms: strip LTO suffixes from static functions
gcc-plugins: remove support for GCC 4.9 and older
hardening: Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO

Merge tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

- mq-deadline accounting improvements (Bart)

- blk-wbt timer fix (Andrea)

- Untangle the block layer includes (Christoph)

- Rework the poll support to be bio based, which will enable adding
support for polling for bio based drivers (Christoph)

- Block layer core support for multi-actuator drives (Damien)

- blk-crypto improvements (Eric)

- Batched tag allocation support (me)

- Request completion batching support (me)

- Plugging improvements (me)

- Shared tag set improvements (John)

- Concurrent queue quiesce support (Ming)

- Cache bdev in ->private_data for block devices (Pavel)

- bdev dio improvements (Pavel)

- Block device invalidation and block size improvements (Xie)

- Various cleanups, fixes, and improvements (Christoph, Jackie,
Masahira, Tejun, Yu, Pavel, Zheng, me)

* tag 'for-5.16/block-2021-10-29' of git://git.kernel.dk/linux-block: (174 commits)
blk-mq-debugfs: Show active requests per queue for shared tags
block: improve readability of blk_mq_end_request_batch()
virtio-blk: Use blk_validate_block_size() to validate block size
loop: Use blk_validate_block_size() to validate block size
nbd: Use blk_validate_block_size() to validate block size
block: Add a helper to validate the block size
block: re-flow blk_mq_rq_ctx_init()
block: prefetch request to be initialized
block: pass in blk_mq_tags to blk_mq_rq_ctx_init()
block: add rq_flags to struct blk_mq_alloc_data
block: add async version of bio_set_polled
block: kill DIO_MULTI_BIO
block: kill unused polling bits in __blkdev_direct_IO()
block: avoid extra iter advance with async iocb
block: Add independent access ranges support
blk-mq: don't issue request directly in case that current is to be blocked
sbitmap: silence data race warning
blk-cgroup: synchronize blkg creation against policy deactivation
block: refactor bio_iov_bvec_set()
block: add single bio async direct IO helper
...

Linux 5.15

Linux 5.15-rc7

kbuild: split DEBUG_CFLAGS out to scripts/Makefile.debug

To slim down the top Makefile, split out the code block surrounded by
ifdef CONFIG_DEBUG_INFO ... endif.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesauniers@google.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>

block: move CONFIG_BLOCK guard to top Makefile

Every object under block/ depends on CONFIG_BLOCK.

Move the guard to the top Makefile since there is no point to
descend into block/ if CONFIG_BLOCK=n.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210927140000.866249-5-masahiroy@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Linux 5.15-rc6

Linux 5.15-rc5

Linux 5.15-rc4

Linux 5.15-rc3