This CONFIG option was added by commit 35bb5b1e0e ("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>
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>
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>
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>
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>
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 $(src)/gen_initramfs.sh as a prerequisite in Makefile
initramfs: make initramfs compression choice non-optional
...
Commit bc081dd6e9 ("kbuild: generate modules.builtin") added
infrastructure to generate modules.builtin, the list of all
builtin modules.
Basically, it works like this:
- Kconfig generates include/config/tristate.conf, the list of
tristate CONFIG options with a value in a capital letter.
- scripts/Makefile.modbuiltin makes Kbuild descend into
directories to collect the information of builtin modules.
I am not a big fan of it because Kbuild ends up with traversing
the source tree twice.
I am not sure how perfectly it should work, but this approach cannot
avoid false positives; even if the relevant CONFIG option is tristate,
some Makefiles forces obj-m to obj-y.
Some examples are:
arch/powerpc/platforms/powermac/Makefile:
obj-$(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>
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
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>
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
...
Commit 2dffd23f81 ("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>
