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2024-09-24kbuild: doc: replace "gcc" in external module descriptionMasahiro Yamada
Avoid "gcc" since it is not the only compiler supported by Kbuild. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-09-24kbuild: doc: describe the -C option precisely for external module buildsMasahiro Yamada
Building external modules is typically done using this command: $ make -C <KERNEL_DIR> M=<EXTMOD_DIR> Here, <KERNEL_DIR> refers to the output directory where the kernel was built, not the kernel source directory. When the kernel is built in the source tree, there is no ambiguity, as the output directory and the source directory are the same. If the kernel was built in a separate build directory, <KERNEL_DIR> should be the kernel output directory. Otherwise, Kbuild cannot locate necessary build artifacts. This has been the method for building external modules against a pre-built kernel in a separate directory for over 20 years. [1] If you pass the kernel source directory to the -C option, you must also specify the kernel build directory using the O= option. This approach works as well, though it results in a slightly longer command: $ make -C <KERNEL_SOURCE_DIR> O=<KERNEL_BUILD_DIR> M=<EXTMOD_DIR> Some people mistakenly believe that O= should specify a build directory for external modules when used together with M=. This commit adds more clarification to Documentation/kbuild/kbuild.rst. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=e321b2ec2eb2993b3d0116e5163c78ad923e3c54 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-09-24kbuild: doc: remove the description about shipped filesMasahiro Yamada
The use of shipped files is discouraged in the upstream kernel these days. [1] Downstream Makefiles have the freedom to use shipped files or other options to handle binaries, but this should not be advertised in the upstream document. [1]: https://lore.kernel.org/all/CAHk-=wgSEi_ZrHdqr=20xv+d6dr5G895CbOAi8ok+7-CQUN=fQ@mail.gmail.com/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-09-24kbuild: doc: drop section numbering, use references in modules.rstMasahiro Yamada
Do similar to commit 1a4c1c9df72e ("docs/kbuild/makefiles: drop section numbering, use references"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-24kbuild: doc: throw out the local table of contents in modules.rstMasahiro Yamada
Do similar to commit 5e8f0ba38a4d ("docs/kbuild/makefiles: throw out the local table of contents"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-24kbuild: doc: remove outdated description of the limitation on -I usageMasahiro Yamada
Kbuild used to manipulate header search paths, enforcing the odd limitation of "no space after -I". Commit cdd750bfb1f7 ("kbuild: remove 'addtree' and 'flags' magic for header search paths") stopped doing that. This limitation no longer exists. Instead, you need to accurately specify the header search path. (In this case, $(src)/include) Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-09-24kbuild: doc: remove description about grepping CONFIG optionsMasahiro Yamada
This description was added 20 years ago [1]. It does not convey any useful information except for a feeling of nostalgia. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=65e433436b5794ae056d22ddba60fe9194bba007 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-09-24kbuild: doc: update the description about Kbuild/Makefile splitMasahiro Yamada
The phrase "In newer versions of the kernel" was added 14 years ago, by commit efdf02cf0651 ("Documentation/kbuild: major edit of modules.txt sections 1-4"). This feature is no longer new, so remove it and update the paragraph. Example 3 was written 20 years ago [1]. There is no need to note about backward compatibility with such an old build system. Remove Example 3 entirely. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=65e433436b5794ae056d22ddba60fe9194bba007 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-09-20kbuild: generate offset range data for builtin modulesKris Van Hees
Create file module.builtin.ranges that can be used to find where built-in modules are located by their addresses. This will be useful for tracing tools to find what functions are for various built-in modules. The offset range data for builtin modules is generated using: - modules.builtin: associates object files with module names - vmlinux.map: provides load order of sections and offset of first member per section - vmlinux.o.map: provides offset of object file content per section - .*.cmd: build cmd file with KBUILD_MODFILE The generated data will look like: .text 00000000-00000000 = _text .text 0000baf0-0000cb10 amd_uncore .text 0009bd10-0009c8e0 iosf_mbi ... .text 00b9f080-00ba011a intel_skl_int3472_discrete .text 00ba0120-00ba03c0 intel_skl_int3472_discrete intel_skl_int3472_tps68470 .text 00ba03c0-00ba08d6 intel_skl_int3472_tps68470 ... .data 00000000-00000000 = _sdata .data 0000f020-0000f680 amd_uncore For each ELF section, it lists the offset of the first symbol. This can be used to determine the base address of the section at runtime. Next, it lists (in strict ascending order) offset ranges in that section that cover the symbols of one or more builtin modules. Multiple ranges can apply to a single module, and ranges can be shared between modules. The CONFIG_BUILTIN_MODULE_RANGES option controls whether offset range data is generated for kernel modules that are built into the kernel image. How it works: 1. The modules.builtin file is parsed to obtain a list of built-in module names and their associated object names (the .ko file that the module would be in if it were a loadable module, hereafter referred to as <kmodfile>). This object name can be used to identify objects in the kernel compile because any C or assembler code that ends up into a built-in module will have the option -DKBUILD_MODFILE=<kmodfile> present in its build command, and those can be found in the .<obj>.cmd file in the kernel build tree. If an object is part of multiple modules, they will all be listed in the KBUILD_MODFILE option argument. This allows us to conclusively determine whether an object in the kernel build belong to any modules, and which. 2. The vmlinux.map is parsed next to determine the base address of each top level section so that all addresses into the section can be turned into offsets. This makes it possible to handle sections getting loaded at different addresses at system boot. We also determine an 'anchor' symbol at the beginning of each section to make it possible to calculate the true base address of a section at runtime (i.e. symbol address - symbol offset). We collect start addresses of sections that are included in the top level section. This is used when vmlinux is linked using vmlinux.o, because in that case, we need to look at the vmlinux.o linker map to know what object a symbol is found in. And finally, we process each symbol that is listed in vmlinux.map (or vmlinux.o.map) based on the following structure: vmlinux linked from vmlinux.a: vmlinux.map: <top level section> <included section> -- might be same as top level section) <object> -- built-in association known <symbol> -- belongs to module(s) object belongs to ... vmlinux linked from vmlinux.o: vmlinux.map: <top level section> <included section> -- might be same as top level section) vmlinux.o -- need to use vmlinux.o.map <symbol> -- ignored ... vmlinux.o.map: <section> <object> -- built-in association known <symbol> -- belongs to module(s) object belongs to ... 3. As sections, objects, and symbols are processed, offset ranges are constructed in a straight-forward way: - If the symbol belongs to one or more built-in modules: - If we were working on the same module(s), extend the range to include this object - If we were working on another module(s), close that range, and start the new one - If the symbol does not belong to any built-in modules: - If we were working on a module(s) range, close that range Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com> Reviewed-by: Nick Alcock <nick.alcock@oracle.com> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Tested-by: Sam James <sam@gentoo.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-07Documentation: kconfig: explicitly document missing promptStephen Brennan
There are a few lines in the kbuild-language.rst document which obliquely reference the behavior of config options without prompts. But there is nothing in the obvious location that explicitly calls out that users cannot edit config options unless they have a prompt. Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-08-16Documentation/llvm: turn make command for ccache into code blockJavier Carrasco
The command provided to use ccache with clang is not a literal code block. Once built, the documentation displays the '' symbols as a " character, which is wrong, and the command can not be applied as provided. Turn the command into a literal code block. Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-24kbuild: doc: gcc to CC changeIvan Davydov
In this part of the documentation, $(CC) is meant, but gcc is written. Signed-off-by: Ivan Davydov <davydoff33@yandex.ru> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-07-16kconfig: remove tristate choice supportMasahiro Yamada
I previously submitted a fix for a bug in the choice feature [1], where I mentioned, "Another (much cleaner) approach would be to remove the tristate choice support entirely". There are more issues in the tristate choice feature. For example, you can observe a couple of bugs in the following test code. [Test Code] config MODULES def_bool y modules choice prompt "tristate choice" default A config A tristate "A" config B tristate "B" endchoice Bug 1: the 'default' property is not correctly processed 'make alldefconfig' produces: CONFIG_MODULES=y # CONFIG_A is not set # CONFIG_B is not set However, the correct output should be: CONFIG_MODULES=y CONFIG_A=y # CONFIG_B is not set The unit test file, scripts/kconfig/tests/choice/alldef_expected_config, is wrong as well. Bug 2: choice members never get 'y' with randconfig For the test code above, the following combinations are possible: A B (1) y n (2) n y (3) m m (4) m n (5) n m (6) n n 'make randconfig' never produces (1) or (2). These bugs are fixable, but a more critical problem is the lack of a sensible syntax to specify the default for the tristate choice. The default for the choice must be one of the choice members, which cannot specify any of the patterns (3) through (6) above. In addition, I have never seen it being used in a useful way. The following commits removed unnecessary use of tristate choices: - df8df5e4bc37 ("usb: get rid of 'choice' for legacy gadget drivers") - bfb57ef0544a ("rapidio: remove choice for enumeration") This commit removes the tristate choice support entirely, which allows me to delete a lot of code, making further refactoring easier. Note: This includes the revert of commit fa64e5f6a35e ("kconfig/symbol.c: handle choice_values that depend on 'm' symbols"). It was suspicious because it did not address the root cause but introduced inconsistency in visibility between choice members and other symbols. [1]: https://lore.kernel.org/linux-kbuild/20240427104231.2728905-1-masahiroy@kernel.org/T/#m0a1bb6992581462ceca861b409bb33cb8fd7dbae Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-06-26kbuild: doc: Update default INSTALL_MOD_DIR from extra to updatesMark-PK Tsai
The default INSTALL_MOD_DIR was changed from 'extra' to 'updates' in commit b74d7bb7ca24 ("kbuild: Modify default INSTALL_MOD_DIR from extra to updates"). This commit updates the documentation to align with the latest kernel. Fixes: b74d7bb7ca24 ("kbuild: Modify default INSTALL_MOD_DIR from extra to updates") Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-06-06kconfig: doc: document behavior of 'select' and 'imply' followed by 'if'Masahiro Yamada
Documentation/kbuild/kconfig-language.rst explains the behavior of 'select' as follows: reverse dependencies can be used to force a lower limit of another symbol. The value of the current menu symbol is used as the minimal value <symbol> can be set to. This is not true when the 'select' property is followed by 'if'. [Test Code] config MODULES def_bool y modules config A def_tristate y select C if B config B def_tristate m config C tristate [Result] CONFIG_MODULES=y CONFIG_A=y CONFIG_B=m CONFIG_C=m If "the value of A is used as the minimal value C can be set to", C must be 'y'. The actual behavior is "C is selected by (A && B)". The lower limit of C is downgraded due to B being 'm'. This behavior is kind of weird, and this has arisen several times in the mailing list. I do not know whether it is a bug or intended behavior. Anyway, it is not feasible to change it now because many Kconfig files are written based on this behavior. The same applies to 'imply'. Document this (but reserve the possibility for a future change). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2024-06-06kconfig: doc: fix a typo in the note about 'imply'Masahiro Yamada
This sentence does not make sense due to a typo. Fix it. Fixes: def2fbffe62c ("kconfig: allow symbols implied by y to become m") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2024-05-10kbuild: use $(src) instead of $(srctree)/$(src) for source directoryMasahiro Yamada
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-02kconfig: remove 'optional' property supportMasahiro Yamada
The 'choice' statement is primarily used to exclusively select one option, but the 'optional' property allows all entries to be disabled. In the following example, both A and B can be disabled simultaneously: choice prompt "choose A, B, or nothing" optional config A bool "A" config B bool "B" endchoice You can achieve the equivalent outcome by other means. A common solution is to add another option to guard the choice block. In the following example, you can set ENABLE_A_B_CHOICE=n to disable the entire choice block: choice prompt "choose A or B" depends on ENABLE_A_B_CHOICE config A bool "A" config B bool "B" endchoice Another approach is to insert one more entry: choice prompt "choose A, B, or disable both" config A bool "A" config B bool "B" config DISABLE_A_AND_B bool "choose this to disable both A and B" endchoice Some real examples are DEBUG_INFO_NONE, INITRAMFS_COMPRESSION_NONE, LTO_NONE, etc. The 'optional' property is even more unnecessary for a tristate choice. Without the 'optional' property, you can disable A and B; you can set 'm' in the choice prompt, and disable A and B individually: choice prompt "choose one built-in or make them modular" config A tristate "A" config B tristate "B" endchoice In conclusion, the 'optional' property was unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-03-31Documentation/llvm: Note s390 LLVM=1 support with LLVM 18.1.0 and newerNathan Chancellor
As of the first s390 pull request during the 6.9 merge window, commit 691632f0e869 ("Merge tag 's390-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux"), s390 can be built with LLVM=1 when using LLVM 18.1.0, which is the first version that has SystemZ support implemented in ld.lld and llvm-objcopy. Update the supported architectures table in the Kbuild LLVM documentation to note this explicitly to make it more discoverable by users and other developers. Additionally, this brings s390 in line with the rest of the architectures in the table, which all support LLVM=1. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-03-10kconfig: remove named choice supportMasahiro Yamada
Commit 5a1aa8a1aff6 ("kconfig: add named choice group") did not provide enough explanation regarding its benefits. A use case was found in another project [1] sometime later, this feature has never been used in the kernel. [1]: https://lore.kernel.org/all/201012150034.01356.yann.morin.1998@anciens.enib.fr/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-02-19docs: kbuild/kconfig: reformat/cleanupVegard Nossum
This document was using headings in an odd way, causing the sidebar to be quite messy. I've adding new headings and turned some of the old headings into description lists. The indentation was a mix of spaces and tabs; I've turned them all into 4 spaces so it always reads correctly regardless of tab settings. Also use ``...`` instead of `...`; the difference is that `` is meant for "inline literals" (and renders in a monospace font) while ` is for "interpreted text" (and renders with italics). Also changed the title of the document to be more descriptive. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-02-15docs: kconfig: Fix grammar and formattingThorsten Blum
- Remove unnecessary spaces - Fix grammar s/to solution/solution/ Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-11-04Merge tag 'kbuild-v6.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Implement the binary search in modpost for faster symbol lookup - Respect HOSTCC when linking host programs written in Rust - Change the binrpm-pkg target to generate kernel-devel RPM package - Fix endianness issues for tee and ishtp MODULE_DEVICE_TABLE - Unify vdso_install rules - Remove unused __memexit* annotations - Eliminate stale whitelisting for __devinit/__devexit from modpost - Enable dummy-tools to handle the -fpatchable-function-entry flag - Add 'userldlibs' syntax * tag 'kbuild-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits) kbuild: support 'userldlibs' syntax kbuild: dummy-tools: pretend we understand -fpatchable-function-entry kbuild: Correct missing architecture-specific hyphens modpost: squash ALL_{INIT,EXIT}_TEXT_SECTIONS to ALL_TEXT_SECTIONS modpost: merge sectioncheck table entries regarding init/exit sections modpost: use ALL_INIT_SECTIONS for the section check from DATA_SECTIONS modpost: disallow the combination of EXPORT_SYMBOL and __meminit* modpost: remove EXIT_SECTIONS macro modpost: remove MEM_INIT_SECTIONS macro modpost: remove more symbol patterns from the section check whitelist modpost: disallow *driver to reference .meminit* sections linux/init: remove __memexit* annotations modpost: remove ALL_EXIT_DATA_SECTIONS macro kbuild: simplify cmd_ld_multi_m kbuild: avoid too many execution of scripts/pahole-flags.sh kbuild: remove ARCH_POSTLINK from module builds kbuild: unify no-compiler-targets and no-sync-config-targets kbuild: unify vdso_install rules docs: kbuild: add INSTALL_DTBS_PATH UML: remove unused cmd_vdso_install ...
2023-11-01Merge tag 'asm-generic-6.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull ia64 removal and asm-generic updates from Arnd Bergmann: - The ia64 architecture gets its well-earned retirement as planned, now that there is one last (mostly) working release that will be maintained as an LTS kernel. - The architecture specific system call tables are updated for the added map_shadow_stack() syscall and to remove references to the long-gone sys_lookup_dcookie() syscall. * tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: hexagon: Remove unusable symbols from the ptrace.h uapi asm-generic: Fix spelling of architecture arch: Reserve map_shadow_stack() syscall number for all architectures syscalls: Cleanup references to sys_lookup_dcookie() Documentation: Drop or replace remaining mentions of IA64 lib/raid6: Drop IA64 support Documentation: Drop IA64 from feature descriptions kernel: Drop IA64 support from sig_fault handlers arch: Remove Itanium (IA-64) architecture
2023-11-01kbuild: support 'userldlibs' syntaxMasahiro Yamada
This syntax is useful to specify libraries linked to all userspace programs in the Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-10-18docs: kbuild: add INSTALL_DTBS_PATHRicardo B. Marliere
The documentation for kbuild and makefiles is missing an explanation of a variable important for some architectures. Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-09-25Documentation: kbuild: explain handling optional dependenciesArnd Bergmann
This problem frequently comes up in randconfig testing, with drivers failing to link because of a dependency on an optional feature. The Kconfig language for this is very confusing, so try to document it in "Kconfig hints" section. Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-09-11Documentation: Drop or replace remaining mentions of IA64Ard Biesheuvel
Drop or update mentions of IA64, as appropriate. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-05Merge tag 'kbuild-v6.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Enable -Wenum-conversion warning option - Refactor the rpm-pkg target - Fix scripts/setlocalversion to consider annotated tags for rt-kernel - Add a jump key feature for the search menu of 'make nconfig' - Support Qt6 for 'make xconfig' - Enable -Wformat-overflow, -Wformat-truncation, -Wstringop-overflow, and -Wrestrict warnings for W=1 builds - Replace <asm/export.h> with <linux/export.h> for alpha, ia64, and sparc - Support DEB_BUILD_OPTIONS=parallel=N for the debian source package - Refactor scripts/Makefile.modinst and fix some modules_sign issues - Add a new Kconfig env variable to warn symbols that are not defined anywhere - Show help messages of config fragments in 'make help' * tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (62 commits) kconfig: fix possible buffer overflow kbuild: Show marked Kconfig fragments in "help" kconfig: add warn-unknown-symbols sanity check kbuild: dummy-tools: make MPROFILE_KERNEL checks work on BE Documentation/llvm: refresh docs modpost: Skip .llvm.call-graph-profile section check kbuild: support modules_sign for external modules as well kbuild: support 'make modules_sign' with CONFIG_MODULE_SIG_ALL=n kbuild: move more module installation code to scripts/Makefile.modinst kbuild: reduce the number of mkdir calls during modules_install kbuild: remove $(MODLIB)/source symlink kbuild: move depmod rule to scripts/Makefile.modinst kbuild: add modules_sign to no-{compiler,sync-config}-targets kbuild: do not run depmod for 'make modules_sign' kbuild: deb-pkg: support DEB_BUILD_OPTIONS=parallel=N in debian/rules alpha: remove <asm/export.h> alpha: replace #include <asm/export.h> with #include <linux/export.h> ia64: remove <asm/export.h> ia64: replace #include <asm/export.h> with #include <linux/export.h> sparc: remove <asm/export.h> ...
2023-09-01kconfig: add warn-unknown-symbols sanity checkSergey Senozhatsky
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 <senozhatsky@chromium.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-09-01Documentation/llvm: refresh docsNick Desaulniers
Recent fixes for an embargoed hardware security vulnerability failed to link with ld.lld (LLVM's linker). [0] To be fair, our documentation mentions ``CC=clang`` foremost with ``LLVM=1`` being buried "below the fold." We want to encourage the use of ``LLVM=1`` rather than just ``CC=clang``. Make that suggestion "above the fold" and "front and center" in our docs. While here, the following additional changes were made: - remove the bit about CROSS_COMPILE setting --target=, that's no longer true. - Add ARCH=loongarch to the list of maintained targets (though we're still working on getting defconfig building cleanly at the moment; we're pretty close). - Bump ARCH=powerpc from CC=clang to LLVM=1 status. - Promote ARCH=riscv from being Maintained to being Supported. Android is working towards supporting RISC-V, and we have excellent support from multiple companies in this regard. - Note that the toolchain distribution on kernel.org has been built with profile data from kernel builds. - Note how to use ccache with clang. Link: https://github.com/ClangBuiltLinux/linux/issues/1907 [0] Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-08-13docs: kbuild: Document search jump featureJesse Taube
Menuconfig has a feature where you can "press the key in the (#) prefix to jump directly to that location. You will be returned to the current search results after exiting this new menu." This feature is poorly documented, so add it to the kconfig.rst documentation. Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-07-14kconfig: docs: mention gconfig at top of kconfig.rstRandy Dunlap
Jesse mentioned that gconfig is missing from the top of the kconfig.rst file, so add it for completeness. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: lore.kernel.org/r/CAJFTR8QgYykuEq_AkODEWPUYXncKgRBHOncxT=ypZTQODkyarw@mail.gmail.com Cc: Jesse Taube <mr.bossman075@gmail.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: linux-kbuild@vger.kernel.org Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230704000120.8098-1-rdunlap@infradead.org
2023-06-10kernel-doc: don't let V=1 change outcomeJohannes Berg
The kernel-doc script currently reports a number of issues only in "verbose" mode, but that's initialized from V=1 (via KBUILD_VERBOSE), so if you use KDOC_WERROR=1 then adding V=1 might actually break the build. This is rather unexpected. Change kernel-doc to not change its behaviour wrt. errors (or warnings) when verbose mode is enabled, but rather add separate warning flags (and -Wall) for it. Allow enabling those flags via environment/make variables in the kernel's build system for easier user use, but to not have to parse them in the script itself. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-05-03parisc: update kbuild doc. aliases for parisc64Randy Dunlap
ARCH=parisc64 is now supported for 64-bit parisc builds, so add this alias to the kbuild.rst documentation. Fixes: 3dcfb729b5f4 ("parisc: Make CONFIG_64BIT available for ARCH=parisc64 only") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: linux-kbuild@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Acked-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Helge Deller <deller@gmx.de>
2023-04-27Merge tag 'sh-for-v6.4-tag1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux Pull sh updates from John Paul Adrian Glaubitz: "This is a bit larger than my previous one and mainly consists of clean-up work in the arch/sh directory by Geert Uytterhoeven and Randy Dunlap. Additionally, this fixes a bug in the Storage Queue code that was discovered while I was reviewing a patch to switch the code to the bitmap API by Christophe Jaillet. So this contains both a fix for the original bug in the Storage Queue code that can be backported later as well as the Christophe's patch to swich the code to the bitmap API. Summary: - Use generic GCC library routines - sq: Use the bitmap API when applicable - sq: Fix incorrect element size for allocating bitmap buffer - pci: Remove unused variable in SH-7786 PCI Express code - mcount.S: fix build error when PRINTK is not enabled - remove sh5/sh64 last fragments - math-emu: fix macro redefined warning - init: use OF_EARLY_FLATTREE for early init - nmi_debug: fix return value of __setup handler - SH2007: drop the bad URL info" * tag 'sh-for-v6.4-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux: sh: Replace <uapi/asm/types.h> by <asm-generic/int-ll64.h> sh: Use generic GCC library routines sh: sq: Use the bitmap API when applicable sh: sq: Fix incorrect element size for allocating bitmap buffer sh: pci: Remove unused variable in SH-7786 PCI Express code sh: mcount.S: fix build error when PRINTK is not enabled sh: remove sh5/sh64 last fragments sh: math-emu: fix macro redefined warning sh: init: use OF_EARLY_FLATTREE for early init sh: nmi_debug: fix return value of __setup handler sh: SH2007: drop the bad URL info
2023-04-08Documentation/llvm: Add a note about prebuilt kernel.org toolchainsNathan Chancellor
I recently started uploading prebuilt stable versions of LLVM to kernel.org, which should make building the kernel with LLVM more accessible to maintainers and developers. Link them in the LLVM documentation to make this more visible. Link: https://lore.kernel.org/20230319235619.GA18547@dev-arch.thelio-3990X/ Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Bill Wendling <morbo@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-03-23sh: remove sh5/sh64 last fragmentsRandy Dunlap
A previous patch removed most of the sh5 (sh64) support from the kernel tree. Now remove the last stragglers. Fixes: 37744feebc08 ("sh: remove sh5 support") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: linux-sh@vger.kernel.org Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Link: https://lore.kernel.org/r/20230306040037.20350-6-rdunlap@infradead.org Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2023-02-26Merge tag 'kbuild-v6.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Change V=1 option to print both short log and full command log - Allow V=1 and V=2 to be combined as V=12 - Make W=1 detect wrong .gitignore files - Tree-wide cleanups for unused command line arguments passed to Clang - Stop using -Qunused-arguments with Clang - Make scripts/setlocalversion handle only correct release tags instead of any arbitrary annotated tag - Create Debian and RPM source packages without cleaning the source tree - Various cleanups for packaging * tag 'kbuild-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (74 commits) kbuild: rpm-pkg: remove unneeded KERNELRELEASE from modules/headers_install docs: kbuild: remove description of KBUILD_LDS_MODULE .gitattributes: use 'dts' diff driver for *.dtso files kbuild: deb-pkg: improve the usability of source package kbuild: deb-pkg: fix binary-arch and clean in debian/rules kbuild: tar-pkg: use tar rules in scripts/Makefile.package kbuild: make perf-tar*-src-pkg work without relying on git kbuild: deb-pkg: switch over to source format 3.0 (quilt) kbuild: deb-pkg: make .orig tarball a hard link if possible kbuild: deb-pkg: hide KDEB_SOURCENAME from Makefile kbuild: srcrpm-pkg: create source package without cleaning kbuild: rpm-pkg: build binary packages from source rpm kbuild: deb-pkg: create source package without cleaning kbuild: add a tool to list files ignored by git Documentation/llvm: add Chimera Linux, Google and Meta datacenters setlocalversion: use only the correct release tag for git-describe setlocalversion: clean up the construction of version output .gitignore: ignore *.cover and *.mbx kbuild: remove --include-dir MAKEFLAG from top Makefile kbuild: fix trivial typo in comment ...
2023-02-26docs: kbuild: remove description of KBUILD_LDS_MODULESangmoon Kim
Commit 596b0474d3d9 ("kbuild: preprocess module linker script") removes KBUILD_LDS_MODULE, yet the variable is still mentioned in kbuild documentation. Remove the reference to the now-nonexistent variable. Signed-off-by: Sangmoon Kim <sangmoon.kim@samsung.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-02-15Documentation/llvm: add Chimera Linux, Google and Meta datacentersNick Desaulniers
Chimera Linux is a Linux distribution from 2021 that builds its kernels with Clang. Google transitioned its data center fleet to run Clang built kernels in 2021, and Meta did so as well in 2022. Meta talked about this at LPC 2022 at a talk titled Kernel Live Patching at Scale. These were important milestones for building the kernel with Clang. Making note of them helps improve confidence in the project. Reviewed-by: Tom Rix <trix@redhat.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com> Co-developed-by: Yonghong Song <yhs@fb.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-01-22docs/kbuild/makefiles: unify quotingJani Nikula
Adding any rst quoting seems to be controversial, but at least try to unify the existing quoting a bit, without adding new ones. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-01-22docs/kbuild/makefiles: clean up indentation and whitespaceJani Nikula
Remove the leading whitespaces, and clean up indentation and whitespace in general. Although the diff looks massive, it's trivial with 'diff -w' or 'git show -w'. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-01-22docs/kbuild/makefiles: drop section numbering, use referencesJani Nikula
Drop the manually updated section numbering. It's hard to maintain, and indeed hasn't been updated when sections 3.4 and 7.8 were dropped. Update all the section references to rst references. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-01-22docs/kbuild/makefiles: throw out the local table of contentsJani Nikula
This is not something that should be manually updated. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-01-22docs/kbuild/makefiles: fix header underlineJani Nikula
The "Kbuild syntax for exported headers" section should not be under "Architecture Makefiles" in hierarchy. Bump the header underline from "-" to "=". Signed-off-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-01-22kbuild: drop V=0 supportMasahiro Yamada
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>
2023-01-22Merge 6.2-rc5 into char-misc-nextGreg Kroah-Hartman
We need the char/misc driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-20scripts/tags.sh: choose which directories to exclude from being indexedPaulo Miguel Almeida
It's common for drivers that share same physical components to also duplicate source code (or at least portions of it). A good example is both drivers/gpu/drm/amdgpu/* and drivers/gpu/drm/radeon/* have a header file called atombios.h. While their contents aren't the same, a lot of their structs have the exact same names which makes navigating through the code base a bit messy as cscope will show up 'references' across drivers which aren't exactly correct. Add IGNORE_DIRS variable, which specifies which directories to be ignored from indexing. Example: make ARCH=x86 IGNORE_DIRS="drivers/gpu/drm/radeon tools" cscope Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Vipin Sharma <vipinsh@google.com> Link: https://lore.kernel.org/r/Y5jf59VCL/HAt60q@mail.google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-09docs: kbuild: remove mention to dropped $(objtree) featureMiguel Ojeda
Commit 8d613a1d048c ("kbuild: drop $(objtree)/ prefix support for clean-files") dropped support for prefixing with $(objtree). Thus update the documentation to match that change. Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>