kernel/linux.git/Documentation/kbuild, branch v6.1.168

kconfig: add warn-unknown-symbols sanity check

2025-02-21T12:49:24+00:00

[ Upstream commit 7cd343008b967423b06af8f6d3236749c67d12e8 ] Introduce KCONFIG_WARN_UNKNOWN_SYMBOLS environment variable, which makes Kconfig warn about unknown config symbols. This is especially useful for continuous kernel uprevs when some symbols can be either removed or renamed between kernel releases (which can go unnoticed otherwise). By default KCONFIG_WARN_UNKNOWN_SYMBOLS generates warnings, which are non-terminal. There is an additional environment variable KCONFIG_WERROR that overrides this behaviour and turns warnings into errors. Signed-off-by: Sergey Senozhatsky Signed-off-by: Masahiro Yamada Stable-dep-of: a409fc1463d6 ("kconfig: fix memory leak in sym_warn_unmet_dep()") Signed-off-by: Sasha Levin

Documentation: kbuild: Add description of git for reproducible builds

2022-10-27T15:16:29+00:00

The status of git will affect the final compilation result, add it to the documentation of reproducible builds. Signed-off-by: Dan Li Signed-off-by: Masahiro Yamada

Merge tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2022-10-10T19:00:45+00:00

Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...

Merge tag 'rust-v6.1-rc1' of https://github.com/Rust-for-Linux/linux

2022-10-03T23:39:37+00:00

Pull Rust introductory support from Kees Cook: "The tree has a recent base, but has fundamentally been in linux-next for a year and a half[1]. It's been updated based on feedback from the Kernel Maintainer's Summit, and to gain recent Reviewed-by: tags. Miguel is the primary maintainer, with me helping where needed/wanted. Our plan is for the tree to switch to the standard non-rebasing practice once this initial infrastructure series lands. The contents are the absolute minimum to get Rust code building in the kernel, with many more interfaces[2] (and drivers - NVMe[3], 9p[4], M1 GPU[5]) on the way. The initial support of Rust-for-Linux comes in roughly 4 areas: - Kernel internals (kallsyms expansion for Rust symbols, %pA format) - Kbuild infrastructure (Rust build rules and support scripts) - Rust crates and bindings for initial minimum viable build - Rust kernel documentation and samples Rust support has been in linux-next for a year and a half now, and the short log doesn't do justice to the number of people who have contributed both to the Linux kernel side but also to the upstream Rust side to support the kernel's needs. Thanks to these 173 people, and many more, who have been involved in all kinds of ways: Miguel Ojeda, Wedson Almeida Filho, Alex Gaynor, Boqun Feng, Gary Guo, Björn Roy Baron, Andreas Hindborg, Adam Bratschi-Kaye, Benno Lossin, Maciej Falkowski, Finn Behrens, Sven Van Asbroeck, Asahi Lina, FUJITA Tomonori, John Baublitz, Wei Liu, Geoffrey Thomas, Philip Herron, Arthur Cohen, David Faust, Antoni Boucher, Philip Li, Yujie Liu, Jonathan Corbet, Greg Kroah-Hartman, Paul E. McKenney, Josh Triplett, Kent Overstreet, David Gow, Alice Ryhl, Robin Randhawa, Kees Cook, Nick Desaulniers, Matthew Wilcox, Linus Walleij, Joe Perches, Michael Ellerman, Petr Mladek, Masahiro Yamada, Arnaldo Carvalho de Melo, Andrii Nakryiko, Konstantin Shelekhin, Rasmus Villemoes, Konstantin Ryabitsev, Stephen Rothwell, Andy Shevchenko, Sergey Senozhatsky, John Paul Adrian Glaubitz, David Laight, Nathan Chancellor, Jonathan Cameron, Daniel Latypov, Shuah Khan, Brendan Higgins, Julia Lawall, Laurent Pinchart, Geert Uytterhoeven, Akira Yokosawa, Pavel Machek, David S. Miller, John Hawley, James Bottomley, Arnd Bergmann, Christian Brauner, Dan Robertson, Nicholas Piggin, Zhouyi Zhou, Elena Zannoni, Jose E. Marchesi, Leon Romanovsky, Will Deacon, Richard Weinberger, Randy Dunlap, Paolo Bonzini, Roland Dreier, Mark Brown, Sasha Levin, Ted Ts'o, Steven Rostedt, Jarkko Sakkinen, Michal Kubecek, Marco Elver, Al Viro, Keith Busch, Johannes Berg, Jan Kara, David Sterba, Connor Kuehl, Andy Lutomirski, Andrew Lunn, Alexandre Belloni, Peter Zijlstra, Russell King, Eric W. Biederman, Willy Tarreau, Christoph Hellwig, Emilio Cobos Álvarez, Christian Poveda, Mark Rousskov, John Ericson, TennyZhuang, Xuanwo, Daniel Paoliello, Manish Goregaokar, comex, Josh Stone, Stephan Sokolow, Philipp Krones, Guillaume Gomez, Joshua Nelson, Mats Larsen, Marc Poulhiès, Samantha Miller, Esteban Blanc, Martin Schmidt, Martin Rodriguez Reboredo, Daniel Xu, Viresh Kumar, Bartosz Golaszewski, Vegard Nossum, Milan Landaverde, Dariusz Sosnowski, Yuki Okushi, Matthew Bakhtiari, Wu XiangCheng, Tiago Lam, Boris-Chengbiao Zhou, Sumera Priyadarsini, Viktor Garske, Niklas Mohrin, Nándor István Krácser, Morgan Bartlett, Miguel Cano, Léo Lanteri Thauvin, Julian Merkle, Andreas Reindl, Jiapeng Chong, Fox Chen, Douglas Su, Antonio Terceiro, SeongJae Park, Sergio González Collado, Ngo Iok Ui (Wu Yu Wei), Joshua Abraham, Milan, Daniel Kolsoi, ahomescu, Manas, Luis Gerhorst, Li Hongyu, Philipp Gesang, Russell Currey, Jalil David Salamé Messina, Jon Olson, Raghvender, Angelos, Kaviraj Kanagaraj, Paul Römer, Sladyn Nunes, Mauro Baladés, Hsiang-Cheng Yang, Abhik Jain, Hongyu Li, Sean Nash, Yuheng Su, Peng Hao, Anhad Singh, Roel Kluin, Sara Saa, Geert Stappers, Garrett LeSage, IFo Hancroft, and Linus Torvalds" Link: https://lwn.net/Articles/849849/ [1] Link: https://github.com/Rust-for-Linux/linux/commits/rust [2] Link: https://github.com/metaspace/rust-linux/commit/d88c3744d6cbdf11767e08bad56cbfb67c4c96d0 [3] Link: https://github.com/wedsonaf/linux/commit/9367032607f7670de0ba1537cf09ab0f4365a338 [4] Link: https://github.com/AsahiLinux/linux/commits/gpu/rust-wip [5] * tag 'rust-v6.1-rc1' of https://github.com/Rust-for-Linux/linux: (27 commits) MAINTAINERS: Rust samples: add first Rust examples x86: enable initial Rust support docs: add Rust documentation Kbuild: add Rust support rust: add `.rustfmt.toml` scripts: add `is_rust_module.sh` scripts: add `rust_is_available.sh` scripts: add `generate_rust_target.rs` scripts: add `generate_rust_analyzer.py` scripts: decode_stacktrace: demangle Rust symbols scripts: checkpatch: enable language-independent checks for Rust scripts: checkpatch: diagnose uses of `%pA` in the C side as errors vsprintf: add new `%pA` format specifier rust: export generated symbols rust: add `kernel` crate rust: add `bindings` crate rust: add `macros` crate rust: add `compiler_builtins` crate rust: adapt `alloc` crate to the kernel ...

Merge tag 'docs-6.1' of git://git.lwn.net/linux

2022-10-03T17:23:32+00:00

Pull documentation updates from Jonathan Corbet: "There's not a huge amount of activity in the docs tree this time around, but a few significant changes even so: - A complete rewriting of the top-level index.rst file, which mostly reflects itself in a redone top page in the HTML-rendered docs. The hope is that the new organization will be a friendlier starting point for both users and developers. - Some math-rendering improvements. - A coding-style.rst update on the use of BUG() and WARN() - A big maintainer-PHP guide update. - Some code-of-conduct updates - More Chinese translation work Plus the usual pile of typo fixes, corrections, and updates" * tag 'docs-6.1' of git://git.lwn.net/linux: (66 commits) checkpatch: warn on usage of VM_BUG_ON() and other BUG variants coding-style.rst: document BUG() and WARN() rules ("do not crash the kernel") Documentation: devres: add missing IO helper Documentation: devres: update IRQ helper Documentation/mm: modify page_referenced to folio_referenced Documentation/CoC: Reflect current CoC interpretation and practices docs/doc-guide: Add documentation on SPHINX_IMGMATH docs: process/5.Posting.rst: clarify use of Reported-by: tag docs, kprobes: Fix the wrong location of Kprobes docs: add a man-pages link to the front page docs: put atomic*.txt and memory-barriers.txt into the core-api book docs: move asm-annotations.rst into core-api docs: remove some index.rst cruft docs: reconfigure the HTML left column docs: Rewrite the front page docs: promote the title of process/index.rst Documentation: devres: add missing SPI helper Documentation: devres: add missing PINCTRL helpers docs: hugetlbpage.rst: fix a typo of hugepage size docs/zh_CN: Add new translation of admin-guide/bootconfig.rst ...

kbuild: remove head-y syntax

2022-10-02T09:06:03+00:00

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 Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier

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

2022-10-02T09:04:05+00:00

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 Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier

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

2022-09-28T19:40:16+00:00

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 Reviewed-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada

docs: add Rust documentation

2022-09-28T07:02:45+00:00

Most of the documentation for Rust is written within the source code itself, as it is idiomatic for Rust projects. This applies to both the shared infrastructure at `rust/` as well as any other Rust module (e.g. drivers) written across the kernel. However, these documents contain general information that does not fit particularly well in the source code, like the Quick Start guide. It also contains a few other small changes elsewhere in the documentation folder. Reviewed-by: Kees Cook Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Co-developed-by: Finn Behrens Signed-off-by: Finn Behrens Co-developed-by: Adam Bratschi-Kaye Signed-off-by: Adam Bratschi-Kaye Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Co-developed-by: Michael Ellerman Signed-off-by: Michael Ellerman Co-developed-by: Sven Van Asbroeck Signed-off-by: Sven Van Asbroeck Co-developed-by: Wu XiangCheng Signed-off-by: Wu XiangCheng Co-developed-by: Gary Guo Signed-off-by: Gary Guo Co-developed-by: Boris-Chengbiao Zhou Signed-off-by: Boris-Chengbiao Zhou Co-developed-by: Yuki Okushi Signed-off-by: Yuki Okushi Co-developed-by: Wei Liu Signed-off-by: Wei Liu Co-developed-by: Daniel Xu Signed-off-by: Daniel Xu Co-developed-by: Julian Merkle Signed-off-by: Julian Merkle Signed-off-by: Miguel Ojeda

docs/core-api: expand Fedora instructions for GCC plugins

2022-09-27T19:21:44+00:00

In Fedora 36, cross-compiling an allmodconfig configuration for other architectures on x86 fails with this problem: In file included from ../scripts/gcc-plugins/gcc-common.h:95, from ../scripts/gcc-plugins/latent_entropy_plugin.c:78: /usr/lib/gcc/aarch64-linux-gnu/12/plugin/include/builtins.h:23:10: fatal error: mpc.h: No such file or directory 23 | #include | ^~~~~~~ compilation terminated. In that distro, that header file is available in the separate libmpc-devel package. Although future versions of Fedora might correctly mark that dependency, mention this additional package. To help detect such problems ahead of time, describe the gcc -print-file-name=plugin command that is used by scripts/gcc-plugins/Kconfig to detect plugins [1]. [1] https://lore.kernel.org/lkml/CAHk-=wjjiYjCp61gdAMpDOsUBU-A2hFFKJoVx5VAC7yV4K6WYg@xxxxxxxxxxxxxx/ Fixes: 43e96ef8b70c50f ("docs/core-api: Add Fedora instructions for GCC plugins"); Signed-off-by: Robert Elliott Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20220827193836.2582079-1-elliott@hpe.com Signed-off-by: Jonathan Corbet