kernel/linux.git/scripts/Makefile.compiler, branch v6.12.80

kbuild: rust: add rustc-min-version support function

2025-06-27T10:11:40+00:00

commit ac954145e1ee3f72033161cbe4ac0b16b5354ae7 upstream. Introduce `rustc-min-version` support function that mimics `{gcc,clang}-min-version` ones, following commit 88b61e3bff93 ("Makefile.compiler: replace cc-ifversion with compiler-specific macros"). In addition, use it in the first use case we have in the kernel (which was done independently to minimize the changes needed for the fix). Signed-off-by: Miguel Ojeda Reviewed-by: Fiona Behrens Reviewed-by: Nicolas Schier Signed-off-by: Masahiro Yamada Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

Make 'cc-option' work correctly for the -Wno-xyzzy pattern

2025-06-27T10:11:27+00:00

[ Upstream commit 550ccb178de2f379f5e1a1833dd6f4bdafef4b68 ] This is the follow-up to commit a79be02bba5c ("Fix mis-uses of 'cc-option' for warning disablement") where I mentioned that the best fix would be to just make 'cc-option' a bit smarter, and work for all compiler options, including the '-Wno-xyzzy' pattern that it used to accept unknown options for. It turns out that fixing cc-option is pretty straightforward: just rewrite any '-Wno-xyzzy' option pattern to use '-Wxyzzy' instead for testing. That makes the whole artificial distinction between 'cc-option' and 'cc-disable-warning' go away, and we can happily forget about the odd build rule that you have to treat compiler options that disable warnings specially. The 'cc-disable-warning' helper remains as a backwards compatibility syntax for now, but is implemented in terms of the new and improved cc-option. Acked-by: Masahiro Yamada Cc: Greg Kroah-Hartman Cc: Arnd Bergmann Cc: Stephen Rothwell Cc: Thomas Weißschuh Cc: Nathan Chancellor Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

rust: kbuild: use `pound` to support GNU Make < 4.3

2025-04-25T08:47:49+00:00

commit 1c4494c14b4124f3a13a7f4912b84b633ff4f9ba upstream. GNU Make 4.3 changed the behavior of `#` inside commands in commit c6966b323811 ("[SV 20513] Un-escaped # are not comments in function invocations"): * WARNING: Backward-incompatibility! Number signs (#) appearing inside a macro reference or function invocation no longer introduce comments and should not be escaped with backslashes: thus a call such as: foo := $(shell echo '#') is legal. Previously the number sign needed to be escaped, for example: foo := $(shell echo '\#') Now this latter will resolve to "\#". If you want to write makefiles portable to both versions, assign the number sign to a variable: H := \# foo := $(shell echo '$H') This was claimed to be fixed in 3.81, but wasn't, for some reason. To detect this change search for 'nocomment' in the .FEATURES variable. Unlike other commits in the kernel about this issue, such as commit 633174a7046e ("lib/raid6/test/Makefile: Use $(pound) instead of \# for Make 4.3"), that fixed the issue for newer GNU Makes, in our case it was the opposite, i.e. we need to fix it for the older ones: someone building with e.g. 4.2.1 gets the following error: scripts/Makefile.compiler:81: *** unterminated call to function 'call': missing ')'. Stop. Thus use the existing variable to fix it. Reported-by: moyi geek <1441339168@qq.com> Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/512001985 Cc: stable@vger.kernel.org Fixes: e72a076c620f ("kbuild: fix issues with rustc-option") Reviewed-by: Nicolas Schier Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250414171241.2126137-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: kasan/kbuild: fix missing flags on first build

2025-04-25T08:47:48+00:00

commit 46e24a545cdb4556f8128c90ecc34eeae52477a0 upstream. If KASAN is enabled, and one runs in a clean repository e.g.: make LLVM=1 prepare make LLVM=1 prepare Then the Rust code gets rebuilt, which should not happen. The reason is some of the LLVM KASAN `rustc` flags are added in the second run: -Cllvm-args=-asan-instrumentation-with-call-threshold=10000 -Cllvm-args=-asan-stack=0 -Cllvm-args=-asan-globals=1 -Cllvm-args=-asan-kernel-mem-intrinsic-prefix=1 Further runs do not rebuild Rust because the flags do not change anymore. Rebuilding like that in the second run is bad, even if this just happens with KASAN enabled, but missing flags in the first one is even worse. The root issue is that we pass, for some architectures and for the moment, a generated `target.json` file. That file is not ready by the time `rustc` gets called for the flag test, and thus the flag test fails just because the file is not available, e.g.: $ ... --target=./scripts/target.json ... -Cllvm-args=... error: target file "./scripts/target.json" does not exist There are a few approaches we could take here to solve this. For instance, we could ensure that every time that the config is rebuilt, we regenerate the file and recompute the flags. Or we could use the LLVM version to check for these flags, instead of testing the flag (which may have other advantages, such as allowing us to detect renames on the LLVM side). However, it may be easier than that: `rustc` is aware of the `-Cllvm-args` regardless of the `--target` (e.g. I checked that the list printed is the same, plus that I can check for these flags even if I pass a completely unrelated target), and thus we can just eliminate the dependency completely. Thus filter out the target. This does mean that `rustc-option` cannot be used to test a flag that requires the right target, but we don't have other users yet, it is a minimal change and we want to get rid of custom targets in the future. We could only filter in the case `target.json` is used, to make it work in more cases, but then it would be harder to notice that it may not work in a couple architectures. Cc: Matthew Maurer Cc: Sami Tolvanen Cc: stable@vger.kernel.org Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support") Tested-by: Alice Ryhl Link: https://lore.kernel.org/r/20250408220311.1033475-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

kbuild: fix issues with rustc-option

2024-10-10T20:34:41+00:00

Fix a few different compiler errors that cause rustc-option to give wrong results. If KBUILD_RUSTFLAGS or the flags being tested contain any -Z flags, then the error below is generated. The RUSTC_BOOTSTRAP environment variable is added to fix this error. error: the option `Z` is only accepted on the nightly compiler help: consider switching to a nightly toolchain: `rustup default nightly` note: selecting a toolchain with `+toolchain` arguments require a rustup proxy; see note: for more information about Rust's stability policy, see error: 1 nightly option were parsed Note that RUSTC_BOOTSTRAP is also defined in the top-level Makefile, but Make-exported variables are unfortunately *not* inherited. That said, this is changing as of commit 98da874c4303 ("[SV 10593] Export variables to $(shell ...) commands"), which is part of Make 4.4. The probe may also fail with the error message below. To fix it, the /dev/null argument is replaced with a file containing the crate attribute #![no_core]. The #![no_core] attribute ensures that rustc does not look for the standard library. It's not possible to instead supply a standard library (i.e. `core`) to rustc, as we need `rustc-option` before the Rust standard library is compiled. error[E0463]: can't find crate for `std` | = note: the `aarch64-unknown-none` target may not be installed = help: consider downloading the target with `rustup target add aarch64-unknown-none` = help: consider building the standard library from source with `cargo build -Zbuild-std` The -o and --out-dir parameters are altered to fix this warning: warning: ignoring --out-dir flag due to -o flag The --sysroot flag is provided as we would otherwise require it to be present in KBUILD_RUSTFLAGS. The --emit=obj flag is used to write the resulting object file to /dev/null instead of writing it to a file in $(TMPOUT). I verified that the Kconfig version of rustc-option doesn't have the same issues. Fixes: c42297438aee ("kbuild: rust: Define probing macros for rustc") Co-developed-by: Miguel Ojeda Signed-off-by: Miguel Ojeda Signed-off-by: Alice Ryhl Acked-by: Masahiro Yamada Link: https://lore.kernel.org/r/20241009-rustc-option-bootstrap-v3-1-5fa0d520efba@google.com [ Reworded as discussed in the list. - Miguel ] Signed-off-by: Miguel Ojeda

kbuild: refactor cc-option-yn, cc-disable-warning, rust-option-yn macros

2024-10-09T22:50:58+00:00

cc-option-yn and cc-disable-warning duplicate the compile command seen a few lines above. These can be defined based on cc-option. I also refactored rustc-option-yn in the same way, although there are currently no users of it. Signed-off-by: Masahiro Yamada Reviewed-by: Alice Ryhl Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/r/20241009102821.2675718-1-masahiroy@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust: Define probing macros for rustc

2024-09-16T16:04:37+00:00

Creates flag probe macro variants for `rustc`. These are helpful because: 1. The kernel now supports a minimum `rustc` version rather than a single version. 2. `rustc` links against a range of LLVM revisions, occasionally even ones without an official release number. Since the availability of some Rust flags depends on which LLVM it has been linked against, probing is necessary. Signed-off-by: Matthew Maurer Link: https://github.com/Rust-for-Linux/linux/pull/1087 Link: https://lore.kernel.org/r/20240820194910.187826-2-mmaurer@google.com Signed-off-by: Miguel Ojeda

kbuild: Add -Wa,--fatal-warnings to as-instr invocation

2024-02-17T00:07:07+00:00

Certain assembler instruction tests may only induce warnings from the assembler on an unsupported instruction or option, which causes as-instr to succeed when it was expected to fail. Some tests workaround this limitation by additionally testing that invalid input fails as expected. However, this is fragile if the assembler is changed to accept the invalid input, as it will cause the instruction/option to be unavailable like it was unsupported even when it is. Use '-Wa,--fatal-warnings' in the as-instr macro to turn these warnings into hard errors, which avoids this fragility and makes tests more robust and well formed. Cc: stable@vger.kernel.org Suggested-by: Eric Biggers Signed-off-by: Nathan Chancellor Tested-by: Eric Biggers Tested-by: Andy Chiu Reviewed-by: Andy Chiu Tested-by: Conor Dooley Reviewed-by: Conor Dooley Acked-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240125-fix-riscv-option-arch-llvm-18-v1-1-390ac9cc3cd0@kernel.org Signed-off-by: Palmer Dabbelt

Merge tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2023-07-01T16:24:31+00:00

Pull Kbuild updates from Masahiro Yamada: - Remove the deprecated rule to build *.dtbo from *.dts - Refactor section mismatch detection in modpost - Fix bogus ARM section mismatch detections - Fix error of 'make gtags' with O= option - Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error with the latest LLVM version - Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed - Ignore more compiler-generated symbols for kallsyms - Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles - Enable more kernel-doc warnings with W=2 - Refactor by generating KSYMTAB data by modpost - Deprecate and - Remove the EXPORT_DATA_SYMBOL macro - Move the check for static EXPORT_SYMBOL back to modpost, which makes the build faster - Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm - Warn missing MODULE_DESCRIPTION when building modules with W=1 - Make 'make clean' robust against too long argument error - Exclude more objects from GCOV to fix CFI failures with GCOV - Allow 'make modules_install' to install modules.builtin and modules.builtin.modinfo even when CONFIG_MODULES is disabled - Include modules.builtin and modules.builtin.modinfo in the linux-image Debian package even when CONFIG_MODULES is disabled - Revive "Entering directory" logging for the latest Make version * tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits) modpost: define more R_ARM_* for old distributions kbuild: revive "Entering directory" for Make >= 4.4.1 kbuild: set correct abs_srctree and abs_objtree for package builds scripts/mksysmap: Ignore prefixed KCFI symbols kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb kbuild: builddeb: always make modules_install, to install modules.builtin* modpost: continue even with unknown relocation type modpost: factor out Elf_Sym pointer calculation to section_rel() modpost: factor out inst location calculation to section_rel() kbuild: Disable GCOV for *.mod.o kbuild: Fix CFI failures with GCOV kbuild: make clean rule robust against too long argument error script: modpost: emit a warning when the description is missing kbuild: make modules_install copy modules.builtin(.modinfo) linux/export.h: rename 'sec' argument to 'license' modpost: show offset from symbol for section mismatch warnings modpost: merge two similar section mismatch warnings kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion modpost: use null string instead of NULL pointer for default namespace modpost: squash sym_update_namespace() into sym_add_exported() ...

powerpc: remove checks for binutils older than 2.25

2023-06-27T06:59:29+00:00

Commit e4412739472b ("Documentation: raise minimum supported version of binutils to 2.25") allows us to remove the checks for old binutils. There is no more user for ld-ifversion. Remove it as well. Signed-off-by: Masahiro Yamada Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://msgid.link/20230119082250.151485-1-masahiroy@kernel.org