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2022-10-10Merge tag 'kbuild-v6.1' of ↵Linus Torvalds1-33/+23
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...
2022-10-02kbuild: remove head-y syntaxMasahiro Yamada1-4/+5
Kbuild puts the objects listed in head-y at the head of vmlinux. Conventionally, we do this for head*.S, which contains the kernel entry point. A counter approach is to control the section order by the linker script. Actually, the code marked as __HEAD goes into the ".head.text" section, which is placed before the normal ".text" section. I do not know if both of them are needed. From the build system perspective, head-y is not mandatory. If you can achieve the proper code placement by the linker script only, it would be cleaner. I collected the current head-y objects into head-object-list.txt. It is a whitelist. My hope is it will be reduced in the long run. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-10-02kbuild: use obj-y instead extra-y for objects placed at the headMasahiro Yamada1-17/+1
The objects placed at the head of vmlinux need special treatments: - arch/$(SRCARCH)/Makefile adds them to head-y in order to place them before other archives in the linker command line. - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of obj-y to avoid them going into built-in.a. This commit gets rid of the latter. Create vmlinux.a to collect all the objects that are unconditionally linked to vmlinux. The objects listed in head-y are moved to the head of vmlinux.a by using 'ar m'. With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y for builtin objects. There is no *.o that is directly linked to vmlinux. Drop unneeded code in scripts/clang-tools/gen_compile_commands.py. $(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested by Nathan Chancellor [1]. [1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-09-28Makefile.compiler: replace cc-ifversion with compiler-specific macrosNick Desaulniers1-12/+17
cc-ifversion is GCC specific. Replace it with compiler specific variants. Update the users of cc-ifversion to use these new macros. Link: https://github.com/ClangBuiltLinux/linux/issues/350 Link: https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@mail.gmail.com/ Suggested-by: Bill Wendling <morbo@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-09-28docs: add Rust documentationMiguel Ojeda1-4/+46
Most of the documentation for Rust is written within the source code itself, as it is idiomatic for Rust projects. This applies to both the shared infrastructure at `rust/` as well as any other Rust module (e.g. drivers) written across the kernel. However, these documents contain general information that does not fit particularly well in the source code, like the Quick Start guide. It also contains a few other small changes elsewhere in the documentation folder. Reviewed-by: Kees Cook <keescook@chromium.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Finn Behrens <me@kloenk.de> Signed-off-by: Finn Behrens <me@kloenk.de> Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Co-developed-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com> Co-developed-by: Wu XiangCheng <bobwxc@email.cn> Signed-off-by: Wu XiangCheng <bobwxc@email.cn> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de> Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de> Co-developed-by: Yuki Okushi <jtitor@2k36.org> Signed-off-by: Yuki Okushi <jtitor@2k36.org> Co-developed-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Wei Liu <wei.liu@kernel.org> Co-developed-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Co-developed-by: Julian Merkle <me@jvmerkle.de> Signed-off-by: Julian Merkle <me@jvmerkle.de> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-02-14kbuild: Add environment variables for userprogs flagsElliot Berman1-0/+2
Allow additional arguments be passed to userprogs compilation. Reproducible clang builds need to provide a sysroot and gcc path to ensure the same toolchain is used across hosts. KCFLAGS is not currently used for any user programs compilation, so add new USERCFLAGS and USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS. Clang might detect GCC installation on hosts which have it installed to a default location in /. With addition of these environment variables, you can specify flags such as: $ make USERCFLAGS=--sysroot=/path/to/sysroot This can also be used to specify different sysroots such as musl or bionic which may be installed on the host in paths that the compiler may not search by default. Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-10-24kbuild: use more subdir- for visiting subdirectories while cleaningMasahiro Yamada1-15/+2
Documentation/kbuild/makefiles.rst suggests to use "archclean" for cleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement. Since commit d92cc4d51643 ("kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick for all architectures. This can take advantage of the parallel option (-j) for "make clean". I also cleaned up the comments in arch/$(SRCARCH)/Makefile. The "archdep" target no longer exists. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
2021-02-25Merge tag 'kbuild-v5.12' of ↵Linus Torvalds1-7/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Fix false-positive build warnings for ARCH=ia64 builds - Optimize dictionary size for module compression with xz - Check the compiler and linker versions in Kconfig - Fix misuse of extra-y - Support DWARF v5 debug info - Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x exceeded the limit - Add generic syscall{tbl,hdr}.sh for cleanups across arches - Minor cleanups of genksyms - Minor cleanups of Kconfig * tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (38 commits) initramfs: Remove redundant dependency of RD_ZSTD on BLK_DEV_INITRD kbuild: remove deprecated 'always' and 'hostprogs-y/m' kbuild: parse C= and M= before changing the working directory kbuild: reuse this-makefile to define abs_srctree kconfig: unify rule of config, menuconfig, nconfig, gconfig, xconfig kconfig: omit --oldaskconfig option for 'make config' kconfig: fix 'invalid option' for help option kconfig: remove dead code in conf_askvalue() kconfig: clean up nested if-conditionals in check_conf() kconfig: Remove duplicate call to sym_get_string_value() Makefile: Remove # characters from compiler string Makefile: reuse CC_VERSION_TEXT kbuild: check the minimum linker version in Kconfig kbuild: remove ld-version macro scripts: add generic syscallhdr.sh scripts: add generic syscalltbl.sh arch: syscalls: remove $(srctree)/ prefix from syscall tables arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work gen_compile_commands: prune some directories kbuild: simplify access to the kernel's version ...
2021-02-22Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds1-3/+1
Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (ufs, ibmvfc, qla2xxx, hisi_sas, pm80xx) plus the removal of the gdth driver (which is bound to cause conflicts with a trivial change somewhere). The only big major rework of note is the one from Hannes trying to clean up our result handling code in the drivers to make it consistent" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (194 commits) scsi: MAINTAINERS: Adjust to reflect gdth scsi driver removal scsi: ufs: Give clk scaling min gear a value scsi: lpfc: Fix 'physical' typos scsi: megaraid_mbox: Fix spelling of 'allocated' scsi: qla2xxx: Simplify the calculation of variables scsi: message: fusion: Fix 'physical' typos scsi: target: core: Change ASCQ for residual write scsi: target: core: Signal WRITE residuals scsi: target: core: Set residuals for 4Kn devices scsi: hisi_sas: Add trace FIFO debugfs support scsi: hisi_sas: Flush workqueue in hisi_sas_v3_remove() scsi: hisi_sas: Enable debugfs support by default scsi: hisi_sas: Don't check .nr_hw_queues in hisi_sas_task_prep() scsi: hisi_sas: Remove deferred probe check in hisi_sas_v2_probe() scsi: lpfc: Add auto select on IRQ_POLL scsi: ncr53c8xx: Fix typos scsi: lpfc: Fix ancient double free scsi: qla2xxx: Fix some memory corruption scsi: qla2xxx: Remove redundant NULL check scsi: megaraid: Fix ifnullfree.cocci warnings ...
2021-02-21Merge tag 'oprofile-removal-5.12' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux Pull oprofile and dcookies removal from Viresh Kumar: "Remove oprofile and dcookies support The 'oprofile' user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. The dcookies stuff is only used by the oprofile code. Now that oprofile's support is getting removed from the kernel, there is no need for dcookies as well. Remove kernel's old oprofile and dcookies support" * tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux: fs: Remove dcookies support drivers: Remove CONFIG_OPROFILE support arch: xtensa: Remove CONFIG_OPROFILE support arch: x86: Remove CONFIG_OPROFILE support arch: sparc: Remove CONFIG_OPROFILE support arch: sh: Remove CONFIG_OPROFILE support arch: s390: Remove CONFIG_OPROFILE support arch: powerpc: Remove oprofile arch: powerpc: Stop building and using oprofile arch: parisc: Remove CONFIG_OPROFILE support arch: mips: Remove CONFIG_OPROFILE support arch: microblaze: Remove CONFIG_OPROFILE support arch: ia64: Remove rest of perfmon support arch: ia64: Remove CONFIG_OPROFILE support arch: hexagon: Don't select HAVE_OPROFILE arch: arc: Remove CONFIG_OPROFILE support arch: arm: Remove CONFIG_OPROFILE support arch: alpha: Remove CONFIG_OPROFILE support
2021-02-16kbuild: doc: remove "Objects which export symbols" sectionMasahiro Yamada1-7/+1
EXPORT_SYMBOL is unrelated to makefiles. No need to mention it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-01kbuild: remove PYTHON variableMasahiro Yamada1-1/+1
Python retired in 2020, and some distributions do not provide the 'python' command any more. As in commit 51839e29cb59 ("scripts: switch explicitly to Python 3"), we need to use more specific 'python3' to invoke scripts even if they are written in a way compatible with both Python 2 and 3. This commit removes the variable 'PYTHON', and switches the existing users to 'PYTHON3'. BTW, PEP 394 (https://www.python.org/dev/peps/pep-0394/) is a helpful material. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-01-29arch: sparc: Remove CONFIG_OPROFILE supportViresh Kumar1-1/+0
The "oprofile" user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. Remove the old oprofile's architecture specific support. Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Robert Richter <rric@kernel.org> Acked-by: William Cohen <wcohen@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2021-01-23scsi: Drop gdth driverHannes Reinecke1-3/+1
The gdth driver refers to a SCSI parallel, PCI-only HBA RAID adapter which was manufactured by the now-defunct ICP Vortex company, later acquired by Adaptec and superseded by the aacraid series of controllers. The driver itself would require a major overhaul before any modifications can be attempted, but seeing that it's unlikely to have any users left it should rather be removed completely. Link: https://lore.kernel.org/r/20210113090500.129644-2-hare@suse.de Cautiously-Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-01-10Documentation: kbuild: Fix section referenceViresh Kumar1-1/+1
Section 3.11 was incorrectly called 3.9, fix it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21kbuild: doc: document subdir-y syntaxMasahiro Yamada1-0/+15
There is no explanation about subdir-y. Let's document it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2020-12-21kbuild: doc: clarify the difference between extra-y and always-yMasahiro Yamada1-39/+71
The difference between extra-y and always-y is obscure. Basically, Kbuild builds targets listed in extra-y and always-y in visited Makefiles without relying on any dependency. The difference is that extra-y is used to list the targets needed for vmlinux whereas always-y is used to list the targets that must be always built irrespective of final targets. Kbuild skips extra-y when it is building only modules (i.e. 'make modules'). This is the long-standing behavior since extra-y was introduced in 2003, and it is explained in that commit log [1]. For clarification, this is the extra-y vs always-y table: extra-y always-y 'make' y y 'make vmlinux' y y 'make modules' n y Kbuild skips extra-y also when building external modules since obviously it never builds vmlinux. Unfortunately, extra-y is wrongly used in many places of upstream code, and even in external modules. Using extra-y in external module Makefiles is wrong. What you should use is probably always-y or 'targets'. The current documentation for extra-y is misleading. I rewrote it, and moved it to the section 3.7. always-y is not documented anywhere. I added. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=f94e5fd7e5d09a56a60670a9bb211a791654bba8 Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2020-12-21kbuild: doc: split if_changed explanation to a separate sectionMasahiro Yamada1-42/+52
The if_changed macro is currently explained in the section "Commands useful for building a boot image", but the use of if_changed is not limited to the boot image. It is often used together with custom rules. Let's split it as a separate section, and insert it after the "Custom Rules" section. I slightly reworded the explanation, re-numbered to fill the <deleted> section, and also fixed the broken indentation of the Note: part. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21kbuild: doc: merge 'Special Rules' and 'Custom kbuild commands' sectionsMasahiro Yamada1-48/+40
The two sections "3.10 Special Rules" and "7.8 Custom kbuild commands" are related because you must understand both of them when you write custom rules. Actually I do not understand the policy about what to go into "3 The kbuild files" and what into "7 Architecture Makefile". This commit reworks the custom rule explanation as follows: - Merged "7.8 Custom kbuild commands" into "3.10 Special Rules". - Reword "Special Rules" to "Custom Rules" for consistency. - Update the example for kecho because the blackfin Makefile does not exist any more. - Replace the example for cmd_<command> with a simpler one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21kbuild: doc: fix 'List directories to visit when descending' sectionMasahiro Yamada1-9/+10
Fix stale information: - Fix the section number in the reference from 6.4 to 7.4. - Remove init-y and net-y. They were removed by commit 23febe375d94 ("kbuild: merge init-y into core-y") and commit 95fb6317b3ab ("kbuild: merge net-y and virt-y into drivers-y"), respectively. - Update the example because arch/sparc64/Makefile does not exit. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-12-21kbuild: doc: replace arch/$(ARCH)/ with arch/$(SRCARCH)/Masahiro Yamada1-27/+34
Precisely speaking, the arch directory is specified by $(SRCARCH), not $(ARCH). In old days, $(ARCH) actually matched to the arch directory because 32-bit and 64-bit were supported as separate architectures. Most architectures (except arm/arm64) were unified like follows: arch/i386, arch/x86_64 -> arch/x86 arch/sh, arch/sh64 -> arch/sh arch/sparc, arch/sparc64 -> arch/sparc To not break the user interface, commit 6752ed90da03 ("Kbuild: allow arch/xxx to use a different source path") introduced SRCARCH to point to the arch directory, still allowing to pass in the former ARCH=i386 or ARCH=x86_64. Update the documents for preciseness, and add the explanation of SRCARCH. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2020-12-21kbuild: doc: update the description about kbuild MakefilesMasahiro Yamada1-1/+1
This line was written in 2003. Now we have much more Makefiles. The number of Makefiles is not important. The point is we have a Makefile in (almost) every directory. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-10-14kbuild: doc: describe proper script invocationLukas Bulwahn1-0/+20
During an investigation to fix up the execute bits of scripts in the kernel repository, Andrew Morton and Kees Cook pointed out that the execute bit should not matter, and that build scripts cannot rely on that. Kees could not point to any documentation, though. Masahiro Yamada explained the convention of setting execute bits to make it easier for manual script invocation. Provide some basic documentation how the build shall invoke scripts, such that the execute bits do not matter, and acknowledge that execute bits are useful nonetheless. This serves as reference for further clean-up patches in the future. Suggested-by: Andrew Morton <akpm@linux-foundation.org> Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ujjwal Kumar <ujjwalkumar0501@gmail.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/lkml/20200830174409.c24c3f67addcce0cea9a9d4c@linux-foundation.org/ Link: https://lore.kernel.org/lkml/202008271102.FEB906C88@keescook/ Link: https://lore.kernel.org/linux-kbuild/CAK7LNAQdrvMkDA6ApDJCGr+5db8SiPo=G+p8EiOvnnGvEN80gA@mail.gmail.com/ Link: https://lkml.kernel.org/r/20201001075723.24246-1-lukas.bulwahn@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-03kbuild: Documentation: clean up makefiles.rstRandy Dunlap1-9/+9
This is a general cleanup of kbuild/makefiles.rst: * Use "Chapter" for major heading references and use "section" for the next-level heading references, for consistency. * Section 3.8 was deleted long ago. * Drop the ending ':' in section names in the contents list. * Correct some section numbering references. * Correct verb agreement typo. * Fix run-on sentence punctuation. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-08-09kbuild: introduce hostprogs-always-y and userprogs-always-yMasahiro Yamada1-1/+30
To build host programs, you need to add the program names to 'hostprogs' to use the necessary build rule, but it is not enough to build them because there is no dependency. There are two types of host programs: built as the prerequisite of another (e.g. gen_crc32table in lib/Makefile), or always built when Kbuild visits the Makefile (e.g. genksyms in scripts/genksyms/Makefile). The latter is typical in Makefiles under scripts/, which contains host programs globally used during the kernel build. To build them, you need to add them to both 'hostprogs' and 'always-y'. This commit adds hostprogs-always-y as a shorthand. The same applies to user programs. net/bpfilter/Makefile builds bpfilter_umh on demand, hence always-y is unneeded. In contrast, programs under samples/ are added to both 'userprogs' and 'always-y' so they are always built when Kbuild visits the Makefiles. userprogs-always-y works as a shorthand. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
2020-08-09kbuild: introduce ccflags-remove-y and asflags-remove-yMasahiro Yamada1-0/+14
CFLAGS_REMOVE_<file>.o filters out flags when compiling a particular object, but there is no convenient way to do that for every object in a directory. Add ccflags-remove-y and asflags-remove-y to make it easily. Use ccflags-remove-y to clean up some Makefiles. The add/remove order works as follows: [1] KBUILD_CFLAGS specifies compiler flags used globally [2] ccflags-y adds compiler flags for all objects in the current Makefile [3] ccflags-remove-y removes compiler flags for all objects in the current Makefile (New feature) [4] CFLAGS_<file> adds compiler flags per file. [5] CFLAGS_REMOVE_<file> removes compiler flags per file. Having [3] before [4] allows us to remove flags from most (but not all) objects in the current Makefile. For example, kernel/trace/Makefile removes $(CC_FLAGS_FTRACE) from all objects in the directory, then adds it back to trace_selftest_dynamic.o and CFLAGS_trace_kprobe_selftest.o The same applies to lib/livepatch/Makefile. Please note ccflags-remove-y has no effect to the sub-directories. In contrast, the previous notation got rid of compiler flags also from all the sub-directories. The following are not affected because they have no sub-directories: arch/arm/boot/compressed/ arch/powerpc/xmon/ arch/sh/ kernel/trace/ However, lib/ has several sub-directories. To keep the behavior, I added ccflags-remove-y to all Makefiles in subdirectories of lib/, except the following: lib/vdso/Makefile - Kbuild does not descend into this Makefile lib/raid/test/Makefile - This is not used for the kernel build I think commit 2464a609ded0 ("ftrace: do not trace library functions") excluded too much. In the next commit, I will remove ccflags-remove-y from the sub-directories of lib/. Suggested-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Brendan Higgins <brendanhiggins@google.com> (KUnit) Tested-by: Anders Roxell <anders.roxell@linaro.org>
2020-06-06kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGSMasahiro Yamada1-2/+2
Commit d503ac531a52 ("kbuild: rename LDFLAGS to KBUILD_LDFLAGS") missed to update the documentation. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-17kbuild: doc: document the new syntax 'userprogs'Masahiro Yamada1-48/+135
Kbuild now supports the syntax 'userprogs' to compile userspace programs for the same architecture as the kernel. Insert the section '5 Userspace Program support' to explain it. I copy-pasted '4 Host Program support' and fixed it up. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sam Ravnborg <sam@ravnborg.org>
2020-04-23Documentation: kbuild: fix the section title formatMasahiro Yamada1-1/+2
Make it consistent with the other sections. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-03-13kbuild: doc: fix references to other documentsMasahiro Yamada1-3/+3
All the files in Documentation/kbuild/ were converted to reST. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-27kbuild: get rid of trailing slash from subdir- exampleMasahiro Yamada1-1/+1
obj-* needs a trailing slash for a directory, but subdir-* does not. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-26kbuild: remove wrong documentation about mandatory-yMasahiro Yamada1-3/+0
This sentence does not make sense in the section about mandatory-y. This seems to be a copy-paste mistake of commit fcc8487d477a ("uapi: export all headers under uapi directories"). The correct description would be "The convention is to list one mandatory-y per line ...". I just removed it instead of fixing it. If such information is needed, it could be commented in include/asm-generic/Kbuild and include/uapi/asm-generic/Kbuild. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-03kbuild: rename hostprogs-y/always to hostprogs/always-yMasahiro Yamada1-33/+16
In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-03kbuild: fix the document to use extra-y for vmlinux.ldsMasahiro Yamada1-2/+2
The difference between "always" and "extra-y" is that the targets listed in $(always) are always built, whereas the ones in $(extra-y) are built only when KBUILD_BUILTIN is set. So, "make modules" does not build the targets in $(extra-y). vmlinux.lds is only needed for linking vmlinux. So, adding it to extra-y is more correct. In fact, arch/x86/kernel/Makefile does this. Fix the example code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2019-12-21kbuild: clarify the difference between obj-y and obj-m w.r.t. descendingMasahiro Yamada1-3/+13
Kbuild descends into a directory by either 'y' or 'm', but there is an important difference. Kbuild combines the built-in objects into built-in.a in each directory. The built-in.a in the directory visited by obj-y is merged into the built-in.a in the parent directory. This merge happens recursively when Kbuild is ascending back towards the top directory, then built-in objects are linked into vmlinux eventually. This works properly only when the Makefile specifying obj-y is reachable by the chain of obj-y. On the other hand, Kbuild does not take built-in.a from the directory visited by obj-m. This it, all the objects in that directory are supposed to be modular. If Kbuild descends into a directory by obj-m, but the Makefile in the sub-directory specifies obj-y, those objects are just left orphan. The current statement "Kbuild only uses this information to decide that it needs to visit the directory" is misleading. Clarify the difference. Reported-by: Johan Hovold <johan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Johan Hovold <johan@kernel.org>
2019-11-14kbuild: remove header compile testMasahiro Yamada1-17/+0
There are both positive and negative options about this feature. At first, I thought it was a good idea, but actually Linus stated a negative opinion (https://lkml.org/lkml/2019/9/29/227). I admit it is ugly and annoying. The baseline I'd like to keep is the compile-test of uapi headers. (Otherwise, kernel developers have no way to ensure the correctness of the exported headers.) I will maintain a small build rule in usr/include/Makefile. Remove the other header test functionality. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-10-01kbuild: remove ar-option and KBUILD_ARFLAGSMasahiro Yamada1-5/+0
Commit 40df759e2b9e ("kbuild: Fix build with binutils <= 2.19") introduced ar-option and KBUILD_ARFLAGS to deal with old binutils. According to Documentation/process/changes.rst, the current minimal supported version of binutils is 2.21 so you can assume the 'D' option is always supported. Not only GNU ar but also llvm-ar supports it. With the 'D' option hard-coded, there is no more user of ar-option or KBUILD_ARFLAGS. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.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 Yamada1-0/+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 Torvalds1-6/+6
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 Yamada1-6/+6
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 Chehab1-0/+1
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>
2019-07-13Merge tag 'kbuild-v5.3' of ↵Linus Torvalds1-5/+17
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 ...
2019-06-14docs: kbuild: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-0/+1509
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>
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