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2019-09-22Merge tag 'modules-for-v5.4' of ↵Linus Torvalds2-2/+159
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull modules updates from Jessica Yu: "The main bulk of this pull request introduces a new exported symbol namespaces feature. The number of exported symbols is increasingly growing with each release (we're at about 31k exports as of 5.3-rc7) and we currently have no way of visualizing how these symbols are "clustered" or making sense of this huge export surface. Namespacing exported symbols allows kernel developers to more explicitly partition and categorize exported symbols, as well as more easily limiting the availability of namespaced symbols to other parts of the kernel. For starters, we have introduced the USB_STORAGE namespace to demonstrate the API's usage. I have briefly summarized the feature and its main motivations in the tag below. Summary: - Introduce exported symbol namespaces. This new feature allows subsystem maintainers to partition and categorize their exported symbols into explicit namespaces. Module authors are now required to import the namespaces they need. Some of the main motivations of this feature include: allowing kernel developers to better manage the export surface, allow subsystem maintainers to explicitly state that usage of some exported symbols should only be limited to certain users (think: inter-module or inter-driver symbols, debugging symbols, etc), as well as more easily limiting the availability of namespaced symbols to other parts of the kernel. With the module import requirement, it is also easier to spot the misuse of exported symbols during patch review. Two new macros are introduced: EXPORT_SYMBOL_NS() and EXPORT_SYMBOL_NS_GPL(). The API is thoroughly documented in Documentation/kbuild/namespaces.rst. - Some small code and kbuild cleanups here and there" * tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: Remove leftover '#undef' from export header module: remove unneeded casts in cmp_name() module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES module: remove redundant 'depends on MODULES' module: Fix link failure due to invalid relocation on namespace offset usb-storage: export symbols in USB_STORAGE namespace usb-storage: remove single-use define for debugging docs: Add documentation for Symbol Namespaces scripts: Coccinelle script for namespace dependencies. modpost: add support for generating namespace dependencies export: allow definition default namespaces in Makefiles or sources module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS modpost: add support for symbol namespaces module: add support for symbol namespaces. export: explicitly align struct kernel_symbol module: support reading multiple values per modinfo tag
2019-09-20Merge tag 'kbuild-v5.4' of ↵Linus Torvalds2-61/+34
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - add modpost warn exported symbols marked as 'static' because 'static' and EXPORT_SYMBOL is an odd combination - break the build early if gold linker is used - optimize the Bison rule to produce .c and .h files by a single pattern rule - handle PREEMPT_RT in the module vermagic and UTS_VERSION - warn CONFIG options leaked to the user-space except existing ones - make single targets work properly - rebuild modules when module linker scripts are updated - split the module final link stage into scripts/Makefile.modfinal - fix the missed error code in merge_config.sh - improve the error message displayed on the attempt of the O= build in unclean source tree - remove 'clean-dirs' syntax - disable -Wimplicit-fallthrough warning for Clang - add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC - remove ARCH_{CPP,A,C}FLAGS variables - add $(BASH) to run bash scripts - change *CFLAGS_<basetarget>.o to take the relative path to $(obj) instead of the basename - stop suppressing Clang's -Wunused-function warnings when W=1 - fix linux/export.h to avoid genksyms calculating CRC of trimmed exported symbols - misc cleanups * tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits) genksyms: convert to SPDX License Identifier for lex.l and parse.y modpost: use __section in the output to *.mod.c modpost: use MODULE_INFO() for __module_depends export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols export.h: remove defined(__KERNEL__), which is no longer needed kbuild: allow Clang to find unused static inline functions for W=1 build kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN kbuild: refactor scripts/Makefile.extrawarn merge_config.sh: ignore unwanted grep errors kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj) modpost: add NOFAIL to strndup modpost: add guid_t type definition kbuild: add $(BASH) to run scripts with bash-extension kbuild: remove ARCH_{CPP,A,C}FLAGS kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC kbuild: Do not enable -Wimplicit-fallthrough for clang for now kbuild: clean up subdir-ymn calculation in Makefile.clean kbuild: remove unneeded '+' marker from cmd_clean kbuild: remove clean-dirs syntax kbuild: check clean srctree even earlier ...
2019-09-15Documentation: kbuild: Add document about reproducible buildsBen Hutchings2-0/+123
In the Distribution Kernels track at Linux Plumbers Conference there was some discussion around the difficulty of making kernel builds reproducible. This is a solved problem, but the solutions don't appear to be documented in one place. This document lists the issues I know about and the settings needed to ensure reproducibility. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-09-10docs: Add documentation for Symbol NamespacesMatthias Maennich1-0/+154
Describe using Symbol Namespaces from a perspective of a user. I.e. module authors or subsystem maintainers. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-10modpost: add support for symbol namespacesMatthias Maennich1-2/+5
Add support for symbols that are exported into namespaces. For that, extract any namespace suffix from the symbol name. In addition, emit a warning whenever a module refers to an exported symbol without explicitly importing the namespace that it is defined in. This patch consistently adds the namespace suffix to symbol names exported into Module.symvers. Example warning emitted by modpost in case of the above violation: WARNING: module ums-usbat uses symbol usb_stor_resume from namespace USB_STORAGE, but does not import it. Co-developed-by: Martijn Coenen <maco@android.com> Signed-off-by: Martijn Coenen <maco@android.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-09-06kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARNMasahiro Yamada1-5/+9
KBUILD_ENABLE_EXTRA_GCC_CHECKS started as a switch to add extra warning options for GCC, but now it is a historical misnomer since we use it also for Clang, DTC, and even kernel-doc. Rename it to more sensible, shorter KBUILD_EXTRA_WARN. For the backward compatibility, KBUILD_ENABLE_EXTRA_GCC_CHECKS is still supported (but not advertised in the documentation). I also fixed up 'make help', and updated the documentation. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
2019-09-04kbuild: remove ARCH_{CPP,A,C}FLAGSMasahiro Yamada1-7/+0
These flags were added by commit 61754c18752f ("kbuild: Allow arch Makefiles to override {cpp,ld,c}flags") to allow ARC to override -O2. We did not see any other usage after all. Now that ARC switched to CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3, there is no more user of these variables. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-29kbuild: remove clean-dirs syntaxMasahiro Yamada1-12/+4
The only the difference between clean-files and clean-dirs is the -r option passed to the 'rm' command. You can always pass -r, and then remove the clean-dirs syntax. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-28docs: kbuild: remove cc-ldoption from document againMasahiro Yamada1-15/+0
Commit 055efab3120b ("kbuild: drop support for cc-ldoption") correctly removed the cc-ldoption from Documentation/kbuild/makefiles.txt, but commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst") revived it. I guess it was a rebase mistake. Remove it again. Fixes: cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-28docs: kbuild: fix invalid ReST syntaxMasahiro Yamada1-4/+4
I see the following warnings when I open this document with a ReST viewer, retext: /home/masahiro/ref/linux/Documentation/kbuild/makefiles.rst:1142: (WARNING/2) Inline emphasis start-string without end-string. /home/masahiro/ref/linux/Documentation/kbuild/makefiles.rst:1152: (WARNING/2) Inline emphasis start-string without end-string. /home/masahiro/ref/linux/Documentation/kbuild/makefiles.rst:1154: (WARNING/2) Inline emphasis start-string without end-string. These hunks were added by commit e846f0dc57f4 ("kbuild: add support for ensuring headers are self-contained") and commit 1e21cbfada87 ("kbuild: support header-test-pattern-y"), respectively. They were written not for ReST but for the plain text, and merged via the kbuild tree. In the same development cycle, this document was converted to ReST by commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst"), and merged via the doc sub-system. Merging them together into Linus' tree resulted in the current situation. To fix the syntax, surround the asterisks with back-quotes, and use :: for the code sample. Fixes: 39ceda5ce1b0 ("Merge tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-21kbuild: rebuild modules when module linker scripts are updatedMasahiro Yamada1-0/+5
Currently, the timestamp of module linker scripts are not checked. Add them to the dependency of modules so they are correctly rebuilt. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-21kbuild: move KBUILD_LDS, KBUILD_VMLINUX_{OBJS,LIBS} to makefiles.rstMasahiro Yamada2-14/+14
These three variables are not intended to be tweaked by users. Move them from kbuild.rst to makefiles.rst. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-21kbuild: do not descend to ./Kbuild when cleaningMasahiro Yamada1-6/+0
'make clean' descends into ./Kbuild, but does not clean anything since everything is added to no-clean-files. There is no need to descend to ./Kbuild in the first place. We can drop the no-clean-files assignment. With this, there is no more user of no-clean-files. I will keep it for a while to see whether a new user will appear. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-20Merge tag 'kbuild-v5.3-2' of ↵Linus Torvalds2-9/+8
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - match the directory structure of the linux-libc-dev package to that of Debian-based distributions - fix incorrect include/config/auto.conf generation when Kconfig creates it along with the .config file - remove misleading $(AS) from documents - clean up precious tag files by distclean instead of mrproper - add a new coccinelle patch for devm_platform_ioremap_resource migration - refactor module-related scripts to read modules.order instead of $(MODVERDIR)/*.mod files to get the list of created modules - remove MODVERDIR - update list of header compile-test - add -fcf-protection=none flag to avoid conflict with the retpoline flags when CONFIG_RETPOLINE=y - misc cleanups * tag 'kbuild-v5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits) kbuild: add -fcf-protection=none when using retpoline flags kbuild: update compile-test header list for v5.3-rc1 kbuild: split out *.mod out of {single,multi}-used-m rules kbuild: remove 'prepare1' target kbuild: remove the first line of *.mod files kbuild: create *.mod with full directory path and remove MODVERDIR kbuild: export_report: read modules.order instead of .tmp_versions/*.mod kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod scsi: remove pointless $(MODVERDIR)/$(obj)/53c700.ver kbuild: remove duplication from modules.order in sub-directories kbuild: get rid of kernel/ prefix from in-tree modules.{order,builtin} kbuild: do not create empty modules.order in the prepare stage coccinelle: api: add devm_platform_ioremap_resource script kbuild: compile-test headers listed in header-test-m as well kbuild: remove unused hostcc-option kbuild: remove tag files by distclean instead of mrproper kbuild: add --hash-style= and --build-id unconditionally kbuild: get rid of misleading $(AS) from documents ...
2019-07-17kbuild: get rid of misleading $(AS) from documentsMasahiro Yamada2-9/+8
The assembler files in the kernel are *.S instead of *.s, so they must be preprocessed. Since 'as' of GNU binutils is not able to preprocess, we always use $(CC) as an assembler driver. $(AS) is almost unused in Kbuild. As of v5.2, there is just one place that directly invokes $(AS). $ git grep -e '$(AS)' -e '${AS}' -e '$AS' -e '$(AS:' -e '${AS:' -- :^Documentation drivers/net/wan/Makefile: AS68K = $(AS) The documentation about *_AFLAGS* sounds like the flags were passed to $(AS). This is somewhat misleading. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
2019-07-15docs: kbuild: fix build with pdf and fix some minor issuesMauro Carvalho Chehab5-11/+33
The tag ".. include" should be replaced by ".. literalinclude" at issues.rst, otherwise it causes TeX to crash due to excessive usage of stack with Sphinx 2.0. While here, solve a few minor issues at the kbuild book output by adding extra blank lines. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: add some directories to the main documentation indexMauro Carvalho Chehab1-1/+1
The contents of those directories were orphaned at the documentation body. While those directories could likely be moved to be inside some guide, I'm opting to just adding their indexes to the main one, removing the :orphan: and adding the SPDX header. For the drivers, the rationale is that the documentation contains a mix of Kernelspace, uAPI and admin-guide. So, better to keep them on separate directories, as we've be doing with similar subsystem-specific docs that were not split yet. For the others, well... I'm too lazy to do the move. Also, it seems to make sense to keep at least some of those at the main dir (like kbuild, for example). In any case, a latter patch could do the move. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2019-07-13Merge tag 'kbuild-v5.3' of ↵Linus Torvalds3-12/+26
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - remove headers_{install,check}_all targets - remove unreasonable 'depends on !UML' from CONFIG_SAMPLES - re-implement 'make headers_install' more cleanly - add new header-test-y syntax to compile-test headers - compile-test exported headers to ensure they are compilable in user-space - compile-test headers under include/ to ensure they are self-contained - remove -Waggregate-return, -Wno-uninitialized, -Wno-unused-value flags - add -Werror=unknown-warning-option for Clang - add 128-bit built-in types support to genksyms - fix missed rebuild of modules.builtin - propagate 'No space left on device' error in fixdep to Make - allow Clang to use its integrated assembler - improve some coccinelle scripts - add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute path for $(srctree). - do not ignore errors when compression utility is missing - misc cleanups * tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits) kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix kbuild: Inform user to pass ARCH= for make mrproper kbuild: fix compression errors getting ignored kbuild: add a flag to force absolute path for srctree kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree kbuild: remove src and obj from the top Makefile scripts/tags.sh: remove unused environment variables from comments scripts/tags.sh: drop SUBARCH support for ARM kbuild: compile-test kernel headers to ensure they are self-contained kheaders: include only headers into kheaders_data.tar.xz kheaders: remove meaningless -R option of 'ls' kbuild: support header-test-pattern-y kbuild: do not create wrappers for header-test-y kbuild: compile-test exported headers to ensure they are self-contained init/Kconfig: add CONFIG_CC_CAN_LINK kallsyms: exclude kasan local symbols on s390 kbuild: add more hints about SUBDIRS replacement coccinelle: api/stream_open: treat all wait_.*() calls as blocking coccinelle: put_device: Add a cast to an expression for an assignment coccinelle: put_device: Adjust a message construction ...
2019-07-10kbuild: add a flag to force absolute path for srctreeMasahiro Yamada1-0/+9
In old days, Kbuild always used an absolute path for $(srctree). Since commit 890676c65d69 ("kbuild: Use relative path when building in the source tree"), $(srctree) is '.' when O= was not passed from the command line. Yet, using absolute paths is useful in some cases even without O=, for instance, to create a cscope file with absolute path tags. 'O=.' was known to work as a workaround to force Kbuild to use absolute paths even when you are building in the source tree. Since commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory"), Kbuild is too clever to be tricked. Even if you pass 'O=.' Kbuild notices you are building in the source tree, then use '.' for $(srctree). So, 'make O=. cscope' is no help to create absolute path tags. We cannot force one or the other according to commit e93bc1a0cab3 ("Revert "kbuild: specify absolute paths for cscope""). Both of relative path and absolute path have pros and cons. This commit adds a new flag KBUILD_ABS_SRCTREE to allow users to choose the absolute path for $(srctree). 'make KBUILD_ABS_SRCTREE=1 cscope' will work as a replacement of 'make O=. cscope'. Reported-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-09kbuild: support header-test-pattern-yMasahiro Yamada1-0/+10
In my view, most of headers can be self-contained. So, it would be tedious to add every header to header-test-y explicitly. We usually end up with "all headers with some exceptions". There are two types in exceptions: [1] headers that are never compiled as standalone units For examples, include/linux/compiler-gcc.h is not intended for direct inclusion. We should always exclude such ones. [2] headers that are conditionally compiled as standalone units Some headers can be compiled only for particular architectures. For example, include/linux/arm-cci.h can be compiled only for arm/arm64 because it requires <asm/arm-cci.h> to exist. Clang can compile include/soc/nps/mtm.h only for arc because it contains an arch-specific register in inline assembler. So, you can write Makefile like this: header-test- += linux/compiler-gcc.h header-test-$(CONFIG_ARM) += linux/arm-cci.h header-test-$(CONFIG_ARM64) += linux/arm-cci.h header-test-$(CONFIG_ARC) += soc/nps/mtm.h The new syntax header-test-pattern-y will be useful to specify "the rest". The typical usage is like this: header-test-pattern-y += */*.h This will add all the headers in sub-directories to the test coverage, excluding $(header-test-). In this regards, header-test-pattern-y behaves like a weaker variant of header-test-y. Caveat: The patterns in header-test-pattern-y are prefixed with $(srctree)/$(src)/ but not $(objtree)/$(obj)/. Stale generated headers are often left over when you traverse the git history without cleaning. Wildcard patterns for $(objtree) may match to stale headers, which could fail to compile. One pitfall is $(srctree)/$(src)/ and $(objtree)/$(obj)/ point to the same directory for in-tree building. So, header-test-pattern-y should be used with care since it can potentially match to stale headers. Caveat2: You could use wildcard for header-test-. For example, header-test- += asm-generic/% ... will exclude headers in asm-generic directory. Unfortunately, the wildcard character is '%' instead of '*' here because this is evaluated by $(filter-out ...) whereas header-test-pattern-y is evaluated by $(wildcard ...). This is a kludge, but seems useful in some places... Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jani Nikula <jani.nikula@intel.com>
2019-07-09kbuild: do not create wrappers for header-test-yMasahiro Yamada1-2/+1
header-test-y does not work with headers in sub-directories. For example, you may want to write a Makefile, like this: include/linux/Kbuild: header-test-y += mtd/nand.h This entry will create a wrapper include/linux/mtd/nand.hdrtest.c with the following content: #include "mtd/nand.h" To make this work, we need to add $(srctree)/include/linux to the header search path. It would be tedious to add ccflags-y. Instead, we could change the *.hdrtest.c rule to wrap: #include "nand.h" This works for in-tree build since #include "..." searches in the relative path from the header with this directive. For O=... build, we need to add $(srctree)/include/linux/mtd to the header search path, which will be even more tedious. After all, I thought it would be handier to compile headers directly without creating wrappers. I added a new build rule to compile %.h into %.h.s The target is %.h.s instead of %.h.o because it is slightly faster. Also, as for GCC, an empty assembly is smaller than an empty object. I wrote the build rule: $(CC) $(c_flags) -S -o $@ -x c /dev/null -include $< instead of: $(CC) $(c_flags) -S -o $@ -x c $< Both work fine with GCC, but the latter is bad for Clang. This comes down to the difference in the -Wunused-function policy. GCC does not warn about unused 'static inline' functions at all. Clang does not warn about the ones in included headers, but does about the ones in the source. So, we should handle headers as headers, not as source files. In fact, this has been hidden since commit abb2ea7dfd82 ("compiler, clang: suppress warning for unused static inline functions"), but we should not rely on that. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Tested-by: Jani Nikula <jani.nikula@intel.com>
2019-06-15kbuild: add support for ensuring headers are self-containedJani Nikula1-0/+7
Sometimes it's useful to be able to explicitly ensure certain headers remain self-contained, i.e. that they are compilable as standalone units, by including and/or forward declaring everything they depend on. Add special target header-test-y where individual Makefiles can add headers to be tested if CONFIG_HEADER_TEST is enabled. This will generate a dummy C file per header that gets built as part of extra-y. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-06-15kbuild: remove headers_{install,check}_allMasahiro Yamada2-12/+1
headers_install_all does not make much sense any more because different architectures export different set of uapi/linux/ headers. As you see in include/uapi/linux/Kbuild, the installation of a.out.h, kvm.h, and kvm_para.h is arch-dependent. So, headers_install_all repeats the installation/removal of them. If somebody really thinks it is useful to do headers_install for all architectures, it would be possible by small shell-scripting, but the top Makefile does not have to provide entry targets just for that purpose. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2019-06-14docs: kbuild: convert docs to ReST and rename to *.rstMauro Carvalho Chehab9-499/+778
The kbuild documentation clearly shows that the documents there are written at different times: some use markdown, some use their own peculiar logic to split sections. Convert everything to ReST without affecting too much the author's style and avoiding adding uneeded markups. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-20kbuild: drop support for cc-ldoptionNick Desaulniers1-14/+0
If you want to see if your linker supports a certain flag, then ask the linker directly with ld-option (not the compiler with cc-ldoption). Checking for linker flag support is an antipattern that complicates the usage of various linkers other than bfd via -fuse-ld={bfd|gold|lld}. Cc: clang-built-linux@googlegroups.com Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-05-07moduleparam: Save information about built-in modules in separate fileAlexey Gladkov1-0/+5
Problem: When a kernel module is compiled as a separate module, some important information about the kernel module is available via .modinfo section of the module. In contrast, when the kernel module is compiled into the kernel, that information is not available. Information about built-in modules is necessary in the following cases: 1. When it is necessary to find out what additional parameters can be passed to the kernel at boot time. 2. When you need to know which module names and their aliases are in the kernel. This is very useful for creating an initrd image. Proposal: The proposed patch does not remove .modinfo section with module information from the vmlinux at the build time and saves it into a separate file after kernel linking. So, the kernel does not increase in size and no additional information remains in it. Information is stored in the same format as in the separate modules (null-terminated string array). Because the .modinfo section is already exported with a separate modules, we are not creating a new API. It can be easily read in the userspace: $ tr '\0' '\n' < modules.builtin.modinfo ext4.softdep=pre: crc32c ext4.license=GPL ext4.description=Fourth Extended Filesystem ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others ext4.alias=fs-ext4 ext4.alias=ext3 ext4.alias=fs-ext3 ext4.alias=ext2 ext4.alias=fs-ext2 md_mod.alias=block-major-9-* md_mod.alias=md md_mod.description=MD RAID framework md_mod.license=GPL md_mod.parmtype=create_on_open:bool md_mod.parmtype=start_dirty_degraded:int ... Co-Developed-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org> Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org> Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> Acked-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-17kbuild: force all architectures except um to include mandatory-yMasahiro Yamada1-1/+1
Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes the common Kbuild.asm file. Factor out the duplicated include directives to scripts/Makefile.asm-generic so that no architecture would opt out of the mandatory-y mechanism. um is not forced to include mandatory-y since it is a very exceptional case which does not support UAPI. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-03-04kbuild: remove cc-version macroMasahiro Yamada1-17/+0
There is no more direct user of this macro; it is only used by cc-ifversion. Calling this macro is not efficient since it invokes the compiler to get the compiler version. CONFIG_GCC_VERSION is already calculated in the Kconfig stage, so Makefile can reuse it. Here is a note about the slight difference between cc-version and CONFIG_GCC_VERSION: When using Clang, cc-version is evaluated to '0402' because Clang defines __GNUC__ and __GNUC__MINOR__, and looks like GCC 4.2 in the version point of view. On the other hand, CONFIG_GCC_VERSION=0 when $(CC) is clang. There are currently two users of cc-ifversion: arch/mips/loongson64/Platform arch/powerpc/Makefile They are not affected by this change. The format of cc-version is <major><minor>, while CONFIG_GCC_VERSION <major><minor><patch>. I adjusted cc-ifversion for the difference of the number of digits. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-02-20kbuild: turn '/' into an alias of './'Masahiro Yamada1-1/+1
Commit 06300b21f4c7 ("kbuild: support building individual files for external modules") introduced the '/' target. It works only for external modules to build all .o files, but skip the modpost stage. However, 'make /' looks a bit weird to me. 'make ./' is more sensible if you want to build all objects under the current directory, and it works as expected. Let's change '/' into a phony target that is an alias of './', but I may feel like deprecating it in the future. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-01-28kbuild: merge KBUILD_VMLINUX_{INIT,MAIN} into KBUILD_VMLINUX_OBJSMasahiro Yamada1-10/+5
The top Makefile does not need to export KBUILD_VMLINUX_INIT and KBUILD_VMLINUX_MAIN separately. Put every built-in.a into KBUILD_VMLINUX_OBJS. The order of $(head-y), $(init-y), $(core-y), ... is still retained. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-01-28kbuild: remove top-level built-in.aMasahiro Yamada1-7/+2
The symbol table in the final archive is unneeded; the linker does not require the symbol table after the --whole-archive option. Every object file in the archive is included in the link anyway. Pass thin archives from subdirectories directly to the linker, and remove the final archiving step. Fix up the document and comments as well. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Nicholas Piggin <npiggin@gmail.com>
2019-01-06kbuild: generate asm-generic wrappers if mandatory headers are missingMasahiro Yamada1-3/+6
Some time ago, Sam pointed out a certain degree of overwrap between generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121) I tweaked the meaning of mandatory-y a little bit; now it defines the minimum set of ASM headers that all architectures must have. If arch does not have specific implementation of a mandatory header, Kbuild will let it fallback to the asm-generic one by automatically generating a wrapper. This will allow to drop lots of redundant generic-y defines. Previously, "mandatory" was used in the context of UAPI, but I guess this can be extended to kernel space ASM headers. Suggested-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2018-12-01kbuild: announce removal of SUBDIRS if usedMasahiro Yamada1-6/+1
SUBDIRS has been kept as a backward compatibility since commit ("[PATCH] kbuild: external module support") in 2002. We do not need multiple ways to do the same thing, so I will remove SUBDIRS after the Linux 5.3 release. I cleaned up in-tree code, and updated the document so that nobody would try to use it. Meanwhile, display the following warning if SUBDIRS is used. Makefile:189: ================= WARNING ================ Makefile:190: 'SUBDIRS' will be removed after Linux 5.3 Makefile:191: Please use 'M=' or 'KBUILD_EXTMOD' instead Makefile:192: ========================================== Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Boris Brezillon <boris.brezillon@bootlin.com> # for scx200_docflash.c Acked-by: Guenter Roeck <linux@roeck-us.net> # for scx200_wdt.c
2018-11-01kbuild: remove unused cc-fullversion variableMasahiro Yamada1-15/+0
The last user of cc-fullversion was removed by commit f2910f0e6835 ("powerpc: remove old GCC version checks"). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-09-10Drop all 00-INDEX files from Documentation/Henrik Austad1-14/+0
This is a respin with a wider audience (all that get_maintainer returned) and I know this spams a *lot* of people. Not sure what would be the correct way, so my apologies for ruining your inbox. The 00-INDEX files are supposed to give a summary of all files present in a directory, but these files are horribly out of date and their usefulness is brought into question. Often a simple "ls" would reveal the same information as the filenames are generally quite descriptive as a short introduction to what the file covers (it should not surprise anyone what Documentation/sched/sched-design-CFS.txt covers) A few years back it was mentioned that these files were no longer really needed, and they have since then grown further out of date, so perhaps it is time to just throw them out. A short status yields the following _outdated_ 00-INDEX files, first counter is files listed in 00-INDEX but missing in the directory, last is files present but not listed in 00-INDEX. List of outdated 00-INDEX: Documentation: (4/10) Documentation/sysctl: (0/1) Documentation/timers: (1/0) Documentation/blockdev: (3/1) Documentation/w1/slaves: (0/1) Documentation/locking: (0/1) Documentation/devicetree: (0/5) Documentation/power: (1/1) Documentation/powerpc: (0/5) Documentation/arm: (1/0) Documentation/x86: (0/9) Documentation/x86/x86_64: (1/1) Documentation/scsi: (4/4) Documentation/filesystems: (2/9) Documentation/filesystems/nfs: (0/2) Documentation/cgroup-v1: (0/2) Documentation/kbuild: (0/4) Documentation/spi: (1/0) Documentation/virtual/kvm: (1/0) Documentation/scheduler: (0/2) Documentation/fb: (0/1) Documentation/block: (0/1) Documentation/networking: (6/37) Documentation/vm: (1/3) Then there are 364 subdirectories in Documentation/ with several files that are missing 00-INDEX alltogether (and another 120 with a single file and no 00-INDEX). I don't really have an opinion to whether or not we /should/ have 00-INDEX, but the above 00-INDEX should either be removed or be kept up to date. If we should keep the files, I can try to keep them updated, but I rather not if we just want to delete them anyway. As a starting point, remove all index-files and references to 00-INDEX and see where the discussion is going. Signed-off-by: Henrik Austad <henrik@austad.us> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Just-do-it-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: [Almost everybody else] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-08-22kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txtMichal Suchanek1-1/+1
Fixes: 8377bd2b9ee1 ("kbuild: Rename HOST_LOADLIBES to KBUILD_HOSTLDLIBS") Signed-off-by: Michal Suchanek <msuchanek@suse.de> Acked-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-22kconfig: report recursive dependency involving 'imply'Masahiro Yamada1-2/+1
Currently, Kconfig does not complain about the recursive dependency where 'imply' keywords are involved. [Test Code] config A bool "a" config B bool "b" imply A depends on A In the code above, Kconfig cannot calculate the symbol values correctly due to the circular dependency. For example, allyesconfig followed by syncconfig results in an odd behavior because CONFIG_B becomes visible in syncconfig. $ make allyesconfig scripts/kconfig/conf --allyesconfig Kconfig # # configuration written to .config # $ cat .config # # Automatically generated file; DO NOT EDIT. # Main menu # CONFIG_A=y $ make syncconfig scripts/kconfig/conf --syncconfig Kconfig * * Restart config... * * * Main menu * a (A) [Y/n/?] y b (B) [N/y/?] (NEW) To detect this correctly, sym_check_expr_deps() should recurse to not only sym->rev_dep.expr but also sym->implied.expr . At this moment, sym_check_print_recursive() cannot distinguish 'select' and 'imply' since it does not know the precise context where the recursive dependency has been hit. This will be solved by the next commit. In fact, even the document and the unit-test are confused. Using 'imply' does not solve recursive dependency since 'imply' addresses the unmet direct dependency, which 'select' could cause. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Dirk Gouders <dirk@gouders.net>
2018-08-15Merge tag 'kconfig-v4.19' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig updates from Masahiro Yamada: - show clearer error messages where pkg-config is needed, but not installed - rename SYMBOL_AUTO to SYMBOL_NO_WRITE to reflect its semantics - create all necessary directories by Kconfig tool itself instead of Makefile - update the .config unconditionally when syncconfig is invoked - use 'include' directive instead of '-include' where include/config/{auto,tristate}.conf is mandatory - do not try to update the .config when running install targets - add .DELETE_ON_ERROR to delete partially updated files - misc cleanups and fixes * tag 'kconfig-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: remove P_ENV property type kconfig: remove unused sym_get_env_prop() function kconfig: fix the rule of mainmenu_stmt symbol init/Kconfig: Use short unix-style option instead of --longname Kbuild: Makefile.modbuiltin: include auto.conf and tristate.conf mandatory kbuild: remove auto.conf from prerequisite of phony targets kbuild: do not update config for 'make kernelrelease' kbuild: do not update config when running install targets kbuild: add .DELETE_ON_ERROR special target kbuild: use 'include' directive to load auto.conf from top Makefile kconfig: allow all config targets to write auto.conf if missing kconfig: make syncconfig update .config regardless of sym_change_count kconfig: create directories needed for syncconfig by itself kconfig: remove unneeded directory generation from local*config kconfig: split out useful helpers in confdata.c kconfig: rename file_write_dep and move it to confdata.c kconfig: fix typos in description of "choice" in kconfig-language.txt kconfig: handle format string before calling conf_message_callback() kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE kconfig: check for pkg-config on make {menu,n,g,x}config
2018-07-25kconfig: fix typos in description of "choice" in kconfig-language.txtRandy Dunlap1-2/+2
Fix a couple of punctuation "typos" in the description of the "choice" keyword. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-21kbuild: if_changed: document single use per target limitationDirk Gouders1-0/+6
Users of if_changed could easily feel invited to use it to divide a recipe into parts like: a: prereq FORCE $(call if_changed,do_a) $(call if_changed,do_b) But this is problematic, because if_changed should not be used more than once per target: in the above example, if_changed stores the command-line of the given command in .a.cmd and when a is up-to-date with respect to prereq, the file .a.cmd contains the command-line for the last command executed, i.e. do_b. When the recipe is then executed again, without any change of prerequisites, the command-line check for do_a will fail, do_a will be executed and stored in .a.cmd. The next check, however, will still see the old content (the file isn't re-read) and if_changed will skip do_b, because the command-line test will not recognize a change. On the next execution of the recipe the roles will flip: do_a is OK but do_b not and it will be executed. And so on... Signed-off-by: Dirk Gouders <dirk@gouders.net> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-17kbuild: Use HOST*FLAGS options from the command lineLaura Abbott1-0/+16
Now that we have the rename in place, reuse the HOST*FLAGS options as something that can be set from the command line and included with the rest of the flags. Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-17kbuild: Rename HOSTCFLAGS to KBUILD_HOSTCFLAGSLaura Abbott1-1/+1
In preparation for enabling command line CFLAGS, re-name HOSTCFLAGS to KBUILD_HOSTCFLAGS as the internal use only flags. This should not have any visible effects. Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06kbuild: document the KBUILD_KCONFIG env. variableRandy Dunlap1-0/+5
Add usage info for the Kbuild environment variable KBUILD_KCONFIG. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Cao jin <caoj.fnst@cn.fujitsu.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06kconfig: update user kconfig tools doc.Randy Dunlap1-8/+43
Update Documentation/kbuild/kconfig.txt, which mostly contains user help for using the kernel config tools. - Add mention of 'nconfig' embedded help text. - Make the section on new config symbols readable. - Correct how to find menuconfig search help. - Add section on 'nconfig' usage. - Mention that gconfig has multiple viewing modes/options. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06kbuild: delete INSTALL_FW_PATH from kbuild documentationRandy Dunlap1-9/+0
Removed Kbuild documentation for INSTALL_FW_PATH. The kbuild symbol INSTALL_FW_PATH was removed from Kbuild tools in September 2017 (for 4.14) but the symbol was not deleted from the kbuild documentation, so do that now. Fixes: 5620a0d1aacd ("firmware: delete in-kernel firmware") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: stable@vger.kernel.org # 4.14+ Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06kbuild: update ARCH alias info for sparcRandy Dunlap1-1/+1
The supported alias for building sparc 32-bit is "sparc32", not "sparc", so update the alias documentation for that. Just using "sparc" produces a 64-bit config file. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-06kbuild: update ARCH alias info for shRandy Dunlap1-0/+1
In Kbuild documentation, add alias for 64-bit sh ARCH ("sh64") to the list of ARCH aliases. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-25kconfig: document Kconfig source file commentsRandy Dunlap1-0/+6
I saw this type of Kconfig construct on LKML: config SYMBOOL #bool "prompt string" default y and wondered what it does. Then I wondered if '#' comments are even documented. They aren't, so add a little doc for that. Ah, good. kconfig says: arch/x86/Kconfig:2942:warning: config symbol defined without type Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-14Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variablesLinus Torvalds1-1/+1
The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-11Documentation: kconfig: add recommended way to describe compiler supportMasahiro Yamada1-0/+18
It would be nice if the source code is written in the same style. This proposes the convention for describing the compiler capability in Kconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>