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2020-04-12Linux 5.7-rc1Linus Torvalds
2020-04-09kbuild: support LLVM=1 to switch the default tools to Clang/LLVMMasahiro Yamada
As Documentation/kbuild/llvm.rst implies, building the kernel with a full set of LLVM tools gets very verbose and unwieldy. Provide a single switch LLVM=1 to use Clang and LLVM tools instead of GCC and Binutils. You can pass it from the command line or as an environment variable. Please note LLVM=1 does not turn on the integrated assembler. You need to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the integrated assembler, I think we can make it default. We discussed what we need, and we agreed to go with a simple boolean flag that switches both target and host tools: https://lkml.org/lkml/2020/3/28/494 https://lkml.org/lkml/2020/4/3/43 Some items discussed, but not adopted: - LLVM_DIR When multiple versions of LLVM are installed, I just thought supporting LLVM_DIR=/path/to/my/llvm/bin/ might be useful. CC = $(LLVM_DIR)clang LD = $(LLVM_DIR)ld.lld ... However, we can handle this by modifying PATH. So, we decided to not do this. - LLVM_SUFFIX Some distributions (e.g. Debian) package specific versions of LLVM with naming conventions that use the version as a suffix. CC = clang$(LLVM_SUFFIX) LD = ld.lld(LLVM_SUFFIX) ... will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc., but the suffixed versions in /usr/bin/ are symlinks to binaries in /usr/lib/llvm-#/bin/, so this can also be handled by PATH. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-04-09kbuild: replace AS=clang with LLVM_IAS=1Masahiro Yamada
The 'AS' variable is unused for building the kernel. Only the remaining usage is to turn on the integrated assembler. A boolean flag is a better fit for this purpose. AS=clang was added for experts. So, I replaced it with LLVM_IAS=1, breaking the backward compatibility. Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-04-09kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=yMasahiro Yamada
Kbuild supports not only obj-y but also lib-y to list objects linked to vmlinux. The difference between them is that all the objects from obj-y are forcibly linked to vmlinux, whereas the objects from lib-y are linked as needed; if there is no user of a lib-y object, it is not linked. lib-y is intended to list utility functions that may be called from all over the place (and may be unused at all), but it is a problem for EXPORT_SYMBOL(). Even if there is no call-site in the vmlinux, we need to keep exported symbols for the use from loadable modules. Commit 7f2084fa55e6 ("[kbuild] handle exports in lib-y objects reliably") worked around it by linking a dummy object, lib-ksyms.o, which contains references to all the symbols exported from lib.a in that directory. It uses the linker script command, EXTERN. Unfortunately, the meaning of EXTERN of ld.lld is different from that of ld.bfd. Therefore, this does not work with LD=ld.lld (CBL issue #515). Anyway, the build rule of lib-ksyms.o is somewhat tricky. So, I want to get rid of it. At first, I was thinking of accumulating lib-y objects into obj-y (or even replacing lib-y with obj-y entirely), but the lib-y syntax is used beyond the ordinary use in lib/ and arch/*/lib/. Examples: - drivers/firmware/efi/libstub/Makefile builds lib.a, which is linked into vmlinux in the own way (arm64), or linked to the decompressor (arm, x86). - arch/alpha/lib/Makefile builds lib.a which is linked not only to vmlinux, but also to bootloaders in arch/alpha/boot/Makefile. - arch/xtensa/boot/lib/Makefile builds lib.a for use from arch/xtensa/boot/boot-redboot/Makefile. One more thing, adding everything to obj-y would increase the vmlinux size of allnoconfig (or tinyconfig). For less impact, I tweaked the destination of lib.a at the top Makefile; when CONFIG_MODULES=y, lib.a goes to KBUILD_VMLINUX_OBJS, which is forcibly linked to vmlinux, otherwise lib.a goes to KBUILD_VMLINUX_LIBS as before. The size impact for normal usecases is quite small since at lease one symbol in every lib-y object is eventually called by someone. In case you are intrested, here are the figures. x86_64_defconfig: text data bss dec hex filename 19566602 5422072 1589328 26578002 1958c52 vmlinux.before 19566932 5422104 1589328 26578364 1958dbc vmlinux.after The case with the biggest impact is allnoconfig + CONFIG_MODULES=y. ARCH=x86 allnoconfig + CONFIG_MODULES=y: text data bss dec hex filename 1175162 254740 1220608 2650510 28718e vmlinux.before 1177974 254836 1220608 2653418 287cea vmlinux.after Hopefully this is still not a big deal. The per-file trimming with the static library is not so effective after all. If fine-grained optimization is desired, some architectures support CONFIG_LD_DEAD_CODE_DATA_ELIMINATION, which trims dead code per-symbol basis. When LTO is supported in mainline, even better optimization will be possible. Link: https://github.com/ClangBuiltLinux/linux/issues/515 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-04-09kbuild: Enable -Wtautological-compareNathan Chancellor
Currently, we disable -Wtautological-compare, which in turn disables a bunch of more specific tautological comparison warnings that are useful for the kernel such as -Wtautological-bitwise-compare. See clang's documentation below for the other warnings that are suppressed by -Wtautological-compare. Now that all of the major/noisy warnings have been fixed, enable -Wtautological-compare so that more issues can be caught at build time by various continuous integration setups. -Wtautological-constant-out-of-range-compare is kept disabled under a normal build but visible at W=1 because there are places in the kernel where a constant or variable size can change based on the kernel configuration. These are not fixed in a clean/concise way and the ones I have audited so far appear to be harmless. It is not a subgroup but rather just one warning so we do not lose out on much coverage by default. Link: https://github.com/ClangBuiltLinux/linux/issues/488 Link: http://releases.llvm.org/10.0.0/tools/clang/docs/DiagnosticsReference.html#wtautological-compare Link: https://bugs.llvm.org/show_bug.cgi?id=42666 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-31Merge tag 'kbuild-v5.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: "Build system: - add CONFIG_UNUSED_KSYMS_WHITELIST, which will be useful to define a fixed set of export symbols for Generic Kernel Image (GKI) - allow to run 'make dt_binding_check' without .config - use full schema for checking DT examples in *.yaml files - make modpost fail for missing MODULE_IMPORT_NS(), which makes more sense because we know the produced modules are never loadable - Remove unused 'AS' variable Kconfig: - sanitize DEFCONFIG_LIST, and remove ARCH_DEFCONFIG from Kconfig files - relax the 'imply' behavior so that symbols implied by 'y' can become 'm' - make 'imply' obey 'depends on' in order to make 'imply' really weak Misc: - add documentation on building the kernel with Clang/LLVM - revive __HAVE_ARCH_STRLEN for 32bit sparc to use optimized strlen() - fix warning from deb-pkg builds when CONFIG_DEBUG_INFO=n - various script and Makefile cleanups" * tag 'kbuild-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) Makefile: Update kselftest help information kbuild: deb-pkg: fix warning when CONFIG_DEBUG_INFO is unset kbuild: add outputmakefile to no-dot-config-targets kbuild: remove AS variable net: wan: wanxl: refactor the firmware rebuild rule net: wan: wanxl: use $(M68KCC) instead of $(M68KAS) for rebuilding firmware net: wan: wanxl: use allow to pass CROSS_COMPILE_M68k for rebuilding firmware kbuild: add comment about grouped target kbuild: add -Wall to KBUILD_HOSTCXXFLAGS kconfig: remove unused variable in qconf.cc sparc: revive __HAVE_ARCH_STRLEN for 32bit sparc kbuild: refactor Makefile.dtbinst more kbuild: compute the dtbs_install destination more simply Makefile: disallow data races on gcc-10 as well kconfig: make 'imply' obey the direct dependency kconfig: allow symbols implied by y to become m net: drop_monitor: use IS_REACHABLE() to guard net_dm_hw_report() modpost: return error if module is missing ns imports and MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS=n modpost: rework and consolidate logging interface kbuild: allow to run dt_binding_check without kernel configuration ...
2020-04-01Makefile: Update kselftest help informationShuah Khan
Update kselftest help information. Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-29Linux 5.6Linus Torvalds
2020-03-29kbuild: add outputmakefile to no-dot-config-targetsDavid Engraf
The target outputmakefile is used to generate a Makefile for out-of-tree builds and does not depend on the kernel configuration. Signed-off-by: David Engraf <david.engraf@sysgo.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-29kbuild: remove AS variableMasahiro Yamada
As commit 5ef872636ca7 ("kbuild: get rid of misleading $(AS) from documents") noted, we rarely use $(AS) directly in the kernel build. Now that the only/last user of $(AS) in drivers/net/wan/Makefile was converted to $(CC), $(AS) is no longer used in the build process. You can still pass in AS=clang, which is just a switch to turn on the LLVM integrated assembler. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
2020-03-29kbuild: add comment about grouped targetMasahiro Yamada
GNU Make commit 8c888d95f618 ("[SV 8297] Implement "grouped targets" for explicit rules.") added the '&:' syntax. I think '&:' is a perfect fit here, but we cannot use it any time soon. Just add a TODO comment. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-29kbuild: add -Wall to KBUILD_HOSTCXXFLAGSMasahiro Yamada
Add -Wall to catch more warnings for C++ host programs. When I submitted the previous version, the 0-day bot reported -Wc++11-compat warnings for old GCC: HOSTCXX -fPIC scripts/gcc-plugins/latent_entropy_plugin.o In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/plugin/include/tm.h:28:0, from scripts/gcc-plugins/gcc-common.h:15, from scripts/gcc-plugins/latent_entropy_plugin.c:78: /usr/lib/gcc/x86_64-linux-gnu/4.8/plugin/include/config/elfos.h:102:21: warning: C++11 requires a space between string literal and macro [-Wc++11-compat] fprintf ((FILE), "%s"HOST_WIDE_INT_PRINT_UNSIGNED"\n",\ ^ /usr/lib/gcc/x86_64-linux-gnu/4.8/plugin/include/config/elfos.h:170:24: warning: C++11 requires a space between string literal and macro [-Wc++11-compat] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/plugin/include/tm.h:42:0, from scripts/gcc-plugins/gcc-common.h:15, from scripts/gcc-plugins/latent_entropy_plugin.c:78: /usr/lib/gcc/x86_64-linux-gnu/4.8/plugin/include/defaults.h:126:24: warning: C++11 requires a space between string literal and macro [-Wc++11-compat] fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \ ^ The source of the warnings is in the plugin headers, so we have no control of it. I just suppressed them by adding -Wno-c++11-compat to scripts/gcc-plugins/Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Kees Cook <keescook@chromium.org>
2020-03-25kbuild: compute the dtbs_install destination more simplyMasahiro Yamada
The 'dtbinst_root' is used to remember the root of the in-kernel dts directory (i.e. arch/*/boot/dts), but it looks clumsy. I prefer using two variables 'obj' and 'dst' to track the in-kernel directory and the install destination, respectively. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-22Linux 5.6-rc7Linus Torvalds
2020-03-19Merge tag 'kbuild-fixes-v5.6-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - fix __uint128_t capability test in Kconfig when GCC that defaults to 32-bit is used to build the 64-bit kernel - suppress new noisy Clang warnings -Wpointer-to-enum-cast - move the namespace field in Module.symvers for the backward compatibility reason for the depmod tool - use available compression for initramdisk when INTRAMFS_SOURCE is defined, which was the original behavior - fix modpost to handle correct large section numbers when it refers to modversion CRCs and module namespaces - fix comments and documents * tag 'kbuild-fixes-v5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: scripts/kallsyms: fix wrong kallsyms_relative_base modpost: Get proper section index by get_secindex() instead of st_shndx initramfs: restore default compression behavior modpost: move the namespace field in Module.symvers last kbuild: Disable -Wpointer-to-enum-cast kbuild: doc: fix references to other documents int128: fix __uint128_t compiler test in Kconfig kconfig: introduce m32-flag and m64-flag kbuild: Fix inconsistent comment
2020-03-20Makefile: disallow data races on gcc-10 as wellSergei Trofimovich
gcc-10 will rename --param=allow-store-data-races=0 to -fno-allow-store-data-races. The flag change happened at https://gcc.gnu.org/PR92046. Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-15Linux 5.6-rc6Linus Torvalds
2020-03-13kbuild: allow to run dt_binding_check without kernel configurationMasahiro Yamada
The dt_binding_check target is located outside of the 'ifneq ($(dtstree),) ... endif' block. So, you can run 'make dt_binding_check' on any architecture. This makes a perfect sense because the dt-schema is arch-agnostic. The only one problem I see is that scripts/dtc/dtc is not always built. For example, ARCH=x86 defconfig does not define CONFIG_DTC. Kbuild descends into scripts/dtc/ with doing nothing. Then, it fails to build *.example.dt.yaml files. Let's build scripts/dtc/dtc forcibly when running dt_binding_check. The dt-schema does not depend on any CONFIG option either, so you should be able to run dt_binding_check without the .config file. Going forward, you can directly run 'make dt_binding_check' in a pristine source tree. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org>
2020-03-13kbuild: allow to run dt_binding_check and dtbs_check in a single commandMasahiro Yamada
Since commit 93512dad334d ("dt-bindings: Improve validation build error handling"), 'make dtbs_check' does not validate the schema fully. If you want to check everything, you need to run two commands separately. $ make ARCH=arm dt_binding_check $ make ARCH=arm dtbs_check They are exclusive each other, so you cannot do like this: $ make ARCH=arm dt_binding_check dtbs_check In this case, dt-doc-validate and dt-extract-example are skipped because CHECK_DTBS is set. Let's make it possible to run these two targets in a single command. It will be useful for schema writers. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org>
2020-03-13kbuild: avoid concurrency issue in parallel building dtbs and dtbs_checkMasahiro Yamada
'make dtbs_check' checks the shecma in addition to building *.dtb files, in other words, 'make dtbs_check' is a super-set of 'make dtbs'. So, you do not have to do 'make dtbs dtbs_check', but I want to keep the build system as robust as possible in any use. Currently, 'dtbs' and 'dtbs_check' are independent of each other. In parallel building, two threads descend into arch/*/boot/dts/, one for dtbs and the other for dtbs_check, then end up with building the same DTB simultaneously. This commit fixes the concurrency issue. Otherwise, I see build errors like follows: $ make ARCH=arm64 defconfig $ make -j16 ARCH=arm64 DT_SCHEMA_FILES=Documentation/devicetree/bindings/arm/psci.yaml dtbs dtbs_check <snip> DTC arch/arm64/boot/dts/qcom/sdm845-cheza-r2.dtb DTC arch/arm64/boot/dts/amlogic/meson-gxl-s905x-p212.dtb DTC arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-lite2.dtb DTC arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-lite2.dtb DTC arch/arm64/boot/dts/freescale/imx8mn-evk.dtb DTC arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-one-plus.dtb DTC arch/arm64/boot/dts/zte/zx296718-pcbox.dtb DTC arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dt.yaml DTC arch/arm64/boot/dts/amlogic/meson-gxl-s905d-p230.dtb DTC arch/arm64/boot/dts/xilinx/zynqmp-zc1254-revA.dtb DTC arch/arm64/boot/dts/allwinner/sun50i-h6-pine-h64.dtb DTC arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet-inx.dtb DTC arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-one-plus.dtb CHECK arch/arm64/boot/dts/altera/socfpga_stratix10_socdk.dt.yaml fixdep: error opening file: arch/arm64/boot/dts/allwinner/.sun50i-h6-orangepi-lite2.dtb.d: No such file or directory make[2]: *** [scripts/Makefile.lib:296: arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-lite2.dtb] Error 2 make[2]: *** Deleting file 'arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-lite2.dtb' make[2]: *** Waiting for unfinished jobs.... DTC arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet-kd.dtb DTC arch/arm64/boot/dts/amlogic/meson-gxl-s905d-p231.dtb DTC arch/arm64/boot/dts/xilinx/zynqmp-zc1275-revA.dtb DTC arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dtb fixdep: parse error; no targets found make[2]: *** [scripts/Makefile.lib:296: arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-one-plus.dtb] Error 1 make[2]: *** Deleting file 'arch/arm64/boot/dts/allwinner/sun50i-h6-orangepi-one-plus.dtb' make[1]: *** [scripts/Makefile.build:505: arch/arm64/boot/dts/allwinner] Error 2 make[1]: *** Waiting for unfinished jobs.... DTC arch/arm64/boot/dts/renesas/r8a77951-salvator-xs.dtb Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org>
2020-03-12kbuild: Fix inconsistent commentSZ Lin (林上智)
The commit 2042b5486bd3 ("kbuild: unset variables in top Makefile instead of setting 0") renamed the variable from "config-targets" to "config-build", the comment should be consistent accordingly. Signed-off-by: Kaiden PK Yu (余泊鎧) <KaidenPK.Yu@moxa.com> Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-08Linux 5.6-rc5Linus Torvalds
2020-03-03kbuild: generate autoksyms.h earlyQuentin Perret
When doing a cold build, autoksyms.h starts empty, and is updated late in the build process to have visibility over the symbols used by in-tree drivers. But since the symbol whitelist is known upfront, it can be used to pre-populate autoksyms.h and maximize the amount of code that can be compiled to its final state in a single pass, hence reducing build time. Do this by using gen_autoksyms.sh to initialize autoksyms.h instead of creating an empty file. Acked-by: Nicolas Pitre <nico@fluxnic.net> Tested-by: Matthias Maennich <maennich@google.com> Reviewed-by: Matthias Maennich <maennich@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-03kbuild: use KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LISTMasahiro Yamada
Most of the Kconfig commands (except defconfig and all*config) read the .config file as a base set of CONFIG options. When it does not exist, the files in DEFCONFIG_LIST are searched in this order and loaded if found. I do not see much sense in the last two lines in DEFCONFIG_LIST. [1] ARCH_DEFCONFIG The entry for DEFCONFIG_LIST is guarded by 'depends on !UML'. So, the ARCH_DEFCONFIG definition in arch/x86/um/Kconfig is meaningless. arch/{sh,sparc,x86}/Kconfig define ARCH_DEFCONFIG depending on 32 or 64 bit variant symbols. This is a little bit strange; ARCH_DEFCONFIG should be a fixed string because the base config file is loaded before the symbol evaluation stage. Using KBUILD_DEFCONFIG makes more sense because it is fixed before Kconfig is invoked. Fortunately, arch/{sh,sparc,x86}/Makefile define it in the same way, and it works as expected. Hence, replace ARCH_DEFCONFIG with "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)". [2] arch/$(ARCH)/defconfig This file path is no longer valid. The defconfig files are always located in the arch configs/ directories. $ find arch -name defconfig | sort arch/alpha/configs/defconfig arch/arm64/configs/defconfig arch/csky/configs/defconfig arch/nds32/configs/defconfig arch/riscv/configs/defconfig arch/s390/configs/defconfig arch/unicore32/configs/defconfig The path arch/*/configs/defconfig is already covered by "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)". So, this file path is not necessary. I moved the default KBUILD_DEFCONFIG to the top Makefile. Otherwise, the 7 architectures listed above would end up with endless loop of syncconfig. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-02kbuild: remove cc-option switch from -Wframe-larger-than=Masahiro Yamada
This CONFIG option was added by commit 35bb5b1e0e84 ("Add option to enable -Wframe-larger-than= on gcc 4.4"). At that time, the cc-option check was needed. According to Documentation/process/changes.rst, the current minimal supported version of GCC is 4.6, so you can assume GCC supports it. Clang supports it as well. Remove the cc-option switch and redundant comments. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-03-01Linux 5.6-rc4Linus Torvalds
2020-02-27kbuild: add dt_binding_check to PHONY in a correct placeMasahiro Yamada
The dt_binding_check is added to PHONY, but it is invisible when $(dtstree) is empty. So, it is not specified as phony for ARCH=x86 etc. Add it to PHONY outside the ifneq ... endif block. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Rob Herring <robh@kernel.org>
2020-02-27kbuild: add dtbs_check to PHONYMasahiro Yamada
The dtbs_check should be a phony target, but currently it is not specified so. 'make dtbs_check' works even if a file named 'dtbs_check' exists because it depends on another phony target, scripts_dtc, but we should not rely on it. Add dtbs_check to PHONY. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Rob Herring <robh@kernel.org>
2020-02-27kbuild: add comment for V=2 modeRandy Dunlap
Complete the comments for valid values of KBUILD_VERBOSE, specifically for KBUILD_VERBOSE=2. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-23Linux 5.6-rc3Linus Torvalds
2020-02-16Linux 5.6-rc2Linus Torvalds
2020-02-09Linux 5.6-rc1Linus Torvalds
2020-02-06kbuild: make multiple directory targets workMasahiro Yamada
Currently, the single-target build does not work when two or more sub-directories are given: $ make fs/ kernel/ lib/ CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool make[2]: Nothing to be done for 'kernel/'. make[2]: Nothing to be done for 'fs/'. make[2]: Nothing to be done for 'lib/'. Make it work properly. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-01Merge tag 'kbuild-v5.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - detect missing include guard in UAPI headers - do not create orphan built-in.a or obj-y objects - generate modules.builtin more simply, and drop tristate.conf - simplify built-in initramfs creation - make linux-headers deb package thinner - optimize the deb package build script - misc cleanups * tag 'kbuild-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) builddeb: split libc headers deployment out into a function builddeb: split kernel headers deployment out into a function builddeb: remove redundant make for ARCH=um builddeb: avoid invoking sub-shells where possible builddeb: remove redundant $objtree/ builddeb: match temporary directory name to the package name builddeb: remove unneeded files in hdrobjfiles for headers package kbuild: use -S instead of -E for precise cc-option test in Kconfig builddeb: allow selection of .deb compressor kbuild: remove 'Building modules, stage 2.' log kbuild: remove *.tmp file when filechk fails kbuild: remove PYTHON2 variable modpost: assume STT_SPARC_REGISTER is defined gen_initramfs.sh: remove intermediate cpio_list on errors initramfs: refactor the initramfs build rules gen_initramfs.sh: always output cpio even without -o option initramfs: add default_cpio_list, and delete -d option support initramfs: generate dependency list and cpio at the same time initramfs: specify $(src)/gen_initramfs.sh as a prerequisite in Makefile initramfs: make initramfs compression choice non-optional ...
2020-01-26Linux 5.5Linus Torvalds
2020-01-19Linux 5.5-rc7Linus Torvalds
2020-01-16kbuild: remove PYTHON2 variableMasahiro Yamada
Python 2 has retired. There is no user of this variable. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-12Linux 5.5-rc6Linus Torvalds
2020-01-07kbuild: create modules.builtin without Makefile.modbuiltin or tristate.confMasahiro Yamada
Commit bc081dd6e9f6 ("kbuild: generate modules.builtin") added infrastructure to generate modules.builtin, the list of all builtin modules. Basically, it works like this: - Kconfig generates include/config/tristate.conf, the list of tristate CONFIG options with a value in a capital letter. - scripts/Makefile.modbuiltin makes Kbuild descend into directories to collect the information of builtin modules. I am not a big fan of it because Kbuild ends up with traversing the source tree twice. I am not sure how perfectly it should work, but this approach cannot avoid false positives; even if the relevant CONFIG option is tristate, some Makefiles forces obj-m to obj-y. Some examples are: arch/powerpc/platforms/powermac/Makefile: obj-$(CONFIG_NVRAM:m=y) += nvram.o net/ipv6/Makefile: obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o net/netlabel/Makefile: obj-$(subst m,y,$(CONFIG_IPV6)) += netlabel_calipso.o Nobody has complained about (or noticed) it, so it is probably fine to have false positives in modules.builtin. This commit simplifies the implementation. Let's exploit the fact that every module has MODULE_LICENSE(). (modpost shows a warning if MODULE_LICENSE is missing. If so, 0-day bot would already have blocked such a module.) I added MODULE_FILE to <linux/module.h>. When the code is being compiled as builtin, it will be filled with the file path of the module, and collected into modules.builtin.info. Then, scripts/link-vmlinux.sh extracts the list of builtin modules out of it. This new approach fixes the false-positives above, but adds another type of false-positives; non-modular code may have MODULE_LICENSE() by mistake. This is not a big deal, it is just the code is always orphan. We can clean it up if we like. You can see cleanup examples by: $ git log --grep='make.* explicitly non-modular' To sum up, this commits deletes lots of code, but still produces almost equivalent results. Please note it does not increase the vmlinux size at all. As you can see in include/asm-generic/vmlinux.lds.h, the .modinfo section is discarded in the link stage. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-05Linux 5.5-rc5Linus Torvalds
2019-12-29Linux 5.5-rc4Linus Torvalds
2019-12-22Linux 5.5-rc3Linus Torvalds
2019-12-21Merge tag 'kbuild-fixes-v5.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - fix warning in out-of-tree 'make clean' - add READELF variable to the top Makefile - fix broken builds when LINUX_COMPILE_BY contains a backslash - fix build warning in kallsyms - fix NULL pointer access in expr_eq() in Kconfig - fix missing dependency on rsync in deb-pkg build - remove ---help--- from documentation - fix misleading documentation about directory descending * tag 'kbuild-fixes-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: clarify the difference between obj-y and obj-m w.r.t. descending kconfig: remove ---help--- from documentation scripts: package: mkdebian: add missing rsync dependency kconfig: don't crash on NULL expressions in expr_eq() scripts/kallsyms: fix offset overflow of kallsyms_relative_base mkcompile_h: use printf for LINUX_COMPILE_BY mkcompile_h: git rid of UTS_TRUNCATE from LINUX_COMPILE_{BY,HOST} x86/boot: kbuild: allow readelf executable to be specified kbuild: fix 'No such file or directory' warning when cleaning
2019-12-15Linux 5.5-rc2Linus Torvalds
2019-12-14x86/boot: kbuild: allow readelf executable to be specifiedDmitry Golovin
Introduce a new READELF variable to top-level Makefile, so the name of readelf binary can be specified. Before this change the name of the binary was hardcoded to "$(CROSS_COMPILE)readelf" which might not be present for every toolchain. This allows to build with LLVM Object Reader by using make parameter READELF=llvm-readelf. Link: https://github.com/ClangBuiltLinux/linux/issues/771 Signed-off-by: Dmitry Golovin <dima@golovin.in> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2019-12-08Linux 5.5-rc1Linus Torvalds
2019-12-02Merge tag 'kbuild-v5.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - remove unneeded asm headers from hexagon, ia64 - add 'dir-pkg' target, which works like 'tar-pkg' but skips archiving - add 'helpnewconfig' target, which shows help for new CONFIG options - support 'make nsdeps' for external modules - make rebuilds faster by deleting $(wildcard $^) checks - remove compile tests for kernel-space headers - refactor modpost to simplify modversion handling - make single target builds faster - optimize and clean up scripts/kallsyms.c - refactor various Makefiles and scripts * tag 'kbuild-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (59 commits) MAINTAINERS: update Kbuild/Kconfig maintainer's email address scripts/kallsyms: remove redundant initializers scripts/kallsyms: put check_symbol_range() calls close together scripts/kallsyms: make check_symbol_range() void function scripts/kallsyms: move ignored symbol types to is_ignored_symbol() scripts/kallsyms: move more patterns to the ignored_prefixes array scripts/kallsyms: skip ignored symbols very early scripts/kallsyms: add const qualifiers where possible scripts/kallsyms: make find_token() return (unsigned char *) scripts/kallsyms: replace prefix_underscores_count() with strspn() scripts/kallsyms: add sym_name() to mitigate cast ugliness scripts/kallsyms: remove unneeded length check for prefix matching scripts/kallsyms: remove redundant is_arm_mapping_symbol() scripts/kallsyms: set relative_base more effectively scripts/kallsyms: shrink table before sorting it scripts/kallsyms: fix definitely-lost memory leak scripts/kallsyms: remove unneeded #ifndef ARRAY_SIZE kbuild: make single target builds even faster modpost: respect the previous export when 'exported twice' is warned modpost: do not set ->preloaded for symbols from Module.symvers ...
2019-11-24Linux 5.4Linus Torvalds
2019-11-23kbuild: make single target builds even fasterMasahiro Yamada
Commit 2dffd23f81a3 ("kbuild: make single target builds much faster") made the situation much better. To improve it even more, apply the similar idea to the top Makefile. Trim unrelated directories from build-dirs. The single build code must be moved above the 'descend' target. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Jens Axboe <axboe@kernel.dk>
2019-11-17Linux 5.4-rc8Linus Torvalds