Kbuild changes
==============
* Drop '*_probe' pattern from modpost section check allowlist, which hid
legitimate warnings (Johan Hovold)
* Disable -Wtype-limits altogether, instead of enabling at W=2 (Vincent
Mailhol)
* Improve UAPI testing to skip testing headers that require a libc when
CONFIG_CC_CAN_LINK is not set, opening up testing of headers with no
libc dependencies to more environments (Thomas Weißschuh)
* Update gendwarfksyms documentation with required dependencies (Jihan
LIN)
* Reject invalid LLVM= values to avoid unintentionally falling back to
system toolchain (Thomas Weißschuh)
* Add a script to help run the kernel build process in a container for
consistent environments and testing (Guillaume Tucker)
* Simplify kallsyms by getting rid of the relative base (Ard Biesheuvel)
* Performance and usability improvements to scripts/make_fit.py (Simon
Glass)
* Minor various clean ups and fixes
Kconfig changes
===============
* Move XPM icons to individual files, clearing up GTK deprecation
warnings (Rostislav Krasny)
* Support
depends on FOO if BAR
as syntactic sugar for
depends on FOO || !BAR' (Nicolas Pitre, Graham Roff)
* Refactor merge_config.sh to use awk over shell/sed/grep, dramatically
speeding up processing large number of config fragments (Anders
Roxell, Mikko Rapeli)
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Merge tag 'kbuild-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild/Kconfig updates from Nathan Chancellor:
"Kbuild:
- Drop '*_probe' pattern from modpost section check allowlist, which
hid legitimate warnings (Johan Hovold)
- Disable -Wtype-limits altogether, instead of enabling at W=2
(Vincent Mailhol)
- Improve UAPI testing to skip testing headers that require a libc
when CONFIG_CC_CAN_LINK is not set, opening up testing of headers
with no libc dependencies to more environments (Thomas Weißschuh)
- Update gendwarfksyms documentation with required dependencies
(Jihan LIN)
- Reject invalid LLVM= values to avoid unintentionally falling back
to system toolchain (Thomas Weißschuh)
- Add a script to help run the kernel build process in a container
for consistent environments and testing (Guillaume Tucker)
- Simplify kallsyms by getting rid of the relative base (Ard
Biesheuvel)
- Performance and usability improvements to scripts/make_fit.py
(Simon Glass)
- Minor various clean ups and fixes
Kconfig:
- Move XPM icons to individual files, clearing up GTK deprecation
warnings (Rostislav Krasny)
- Support
depends on FOO if BAR
as syntactic sugar for
depends on FOO || !BAR
(Nicolas Pitre, Graham Roff)
- Refactor merge_config.sh to use awk over shell/sed/grep,
dramatically speeding up processing large number of config
fragments (Anders Roxell, Mikko Rapeli)"
* tag 'kbuild-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (39 commits)
kbuild: remove dependency of run-command on config
scripts/make_fit: Compress dtbs in parallel
scripts/make_fit: Support a few more parallel compressors
kbuild: Support a FIT_EXTRA_ARGS environment variable
scripts/make_fit: Move dtb processing into a function
scripts/make_fit: Support an initial ramdisk
scripts/make_fit: Speed up operation
rust: kconfig: Don't require RUST_IS_AVAILABLE for rustc-option
MAINTAINERS: Add scripts/install.sh into Kbuild entry
modpost: Amend ppc64 save/restfpr symnames for -Os build
MIPS: tools: relocs: Ship a definition of R_MIPS_PC32
streamline_config.pl: remove superfluous exclamation mark
kbuild: dummy-tools: Add python3
scripts: kconfig: merge_config.sh: warn on duplicate input files
scripts: kconfig: merge_config.sh: use awk in checks too
scripts: kconfig: merge_config.sh: refactor from shell/sed/grep to awk
kallsyms: Get rid of kallsyms relative base
mips: Add support for PC32 relocations in vmlinux
Documentation: dev-tools: add container.rst page
scripts: add tool to run containerized builds
...
The root document usually has a special :ref:`genindex` link to the
generated index. This is also the case for Documentation/index.rst. The
other index.rst files deeper in the directory hierarchy usually don't.
For SPHINXDIRS builds, the root document isn't Documentation/index.rst,
but some other index.rst in the hierarchy. Currently they have a
".. only::" block to add the index link when doing SPHINXDIRS html
builds.
This is obviously very tedious and repetitive. The link is also added to
all index.rst files in the hierarchy for SPHINXDIRS builds, not just the
root document.
Put the boilerplate in a sphinx-includes/subproject-index.rst file, and
include it at the end of the root document for subproject builds in an
ad-hoc source-read extension defined in conf.py.
For now, keep having the boilerplate in translations, because this
approach currently doesn't cover translated index link headers.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
[jc: did s/doctree/kern_doc_dir/ ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260123143149.2024303-1-jani.nikula@intel.com>
The indentation in gendwarfksyms.rst currently uses a mix of tabs and
spaces. Convert all indentation to tabs, and match the usage output and
code examples with theirs references.
Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Jihan LIN <linjh22s@gmail.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Link: https://patch.msgid.link/20260114-documents_gendwarfksyms-v2-2-297c98bd62c6@gmail.com
[nathan: Minor commit message formatting adjustment]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Although dependencies for gendwarfksyms were recently added to the
packaging rules [1-2], the corresponding documentation was missing.
Document the required build dependencies for gendwarfksyms, and
include a few examples for installing these dependencies on some
distributions.
[1] commit 657f96cb7c ("kbuild: deb-pkg: Add libdw-dev:native to Build-Depends-Arch")
[2] commit 5bd6bdd0f7 ("kbuild: rpm-pkg: Add (elfutils-devel or libdw-devel) to BuildRequires")
Signed-off-by: Jihan LIN <linjh22s@gmail.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Link: https://patch.msgid.link/20260114-documents_gendwarfksyms-v2-1-297c98bd62c6@gmail.com
[nathan: Applied Petr's suggested changes from review and minor commit
message formatting adjustments]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
kernel-doc is the last documentation-related tool still living outside of
the tools/docs directory; the time has come to move it over.
[mchehab: fixed kdoc lib location]
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <311d17e403524349940a8b12de6b5e91e554b1f4.1768823489.git.mchehab+huawei@kernel.org>
Fix various typos and grammatical errors across documentation files:
- Fix missing preposition 'in' in process/changes.rst
- Correct 'result by' to 'result from' in admin-guide/README.rst
- Fix 'before hand' to 'beforehand' in cgroup-v1/hugetlb.rst
- Correct 'allows to limit' to 'allows limiting' in hugetlb.rst,
cgroup-v2.rst, and kconfig-language.rst
- Fix 'needs precisely know' to 'needs to precisely know'
- Correct 'overcommited' to 'overcommitted' in hugetlb.rst
- Fix subject-verb agreement: 'never causes' to 'never cause'
- Fix 'there is enough' to 'there are enough' in hugetlb.rst
- Fix 'metadatas' to 'metadata' in filesystems/erofs.rst
- Fix 'hardwares' to 'hardware' in scsi/ChangeLog.sym53c8xx
Signed-off-by: Nauman Sabir <officialnaumansabir@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Message-ID: <20260115230110.7734-1-officialnaumansabir@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Extend the "depends on" syntax to support conditional dependencies
using "depends on X if Y". While functionally equivalent to "depends
on X || (Y == n)", "depends on X if Y" is much more readable and
makes the kconfig language uniform in supporting the "if <expr>"
suffix.
This also improves readability for "optional" dependencies, which
are the subset of conditional dependencies where X is Y.
Previously such optional dependencies had to be expressed as
the counterintuitive "depends on X || !X", now this can be
represented as "depends on X if X".
The change is implemented by converting the "X if Y" syntax into the
"X || (Y == n)" syntax during "depends on" token processing.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
[Graham Roff: Rewrote commit message, updated patch, added tests]
Signed-off-by: Graham Roff <grahamr@qti.qualcomm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20251215-kconfig_conditional_deps-v3-1-59519af0a5df@qti.qualcomm.com
[nathan: Minor adjustments to spacing]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
The correct command to generate header files is
make headers_install.
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251220125434.2430-1-cp0613@linux.alibaba.com>
This patch adds an example of how to set KBUILD_BUILD_TIMESTAMP to a
specific date. Also, note that the provided timestamp is used for
initramfs mtime fields, which are 32-bit and thus limited to dates
between the Unix epoch and 2106-02-07 06:28:15 UTC. Dates outside this
range will cause errors.
Suggested-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251017021209.6586-1-gang.yan@linux.dev
Signed-off-by: Nicolas Schier <nsc@kernel.org>
- Extend modules.builtin.modinfo to include module aliases from
MODULE_DEVICE_TABLE for builtin modules so that userspace tools (such
as kmod) can verify that a particular module alias will be handled by
a builtin module.
- Bump the minimum version of LLVM for building the kernel to 15.0.0.
- Upgrade several userspace API checks in headers_check.pl to errors.
- Unify and consolidate CONFIG_WERROR / W=e handling.
- Turn assembler and linker warnings into errors with CONFIG_WERROR /
W=e.
- Respect CONFIG_WERROR / W=e when building userspace programs
(userprogs).
- Enable -Werror unconditionally when building host programs
(hostprogs).
- Support copy_file_range() and data segment alignment in gen_init_cpio
to improve performance on filesystems that support reflinks such as
btrfs and XFS.
- Miscellaneous small changes to scripts and configuration files.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
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Merge tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild updates from Nathan Chancellor:
- Extend modules.builtin.modinfo to include module aliases from
MODULE_DEVICE_TABLE for builtin modules so that userspace tools (such
as kmod) can verify that a particular module alias will be handled by
a builtin module
- Bump the minimum version of LLVM for building the kernel to 15.0.0
- Upgrade several userspace API checks in headers_check.pl to errors
- Unify and consolidate CONFIG_WERROR / W=e handling
- Turn assembler and linker warnings into errors with CONFIG_WERROR /
W=e
- Respect CONFIG_WERROR / W=e when building userspace programs
(userprogs)
- Enable -Werror unconditionally when building host programs
(hostprogs)
- Support copy_file_range() and data segment alignment in gen_init_cpio
to improve performance on filesystems that support reflinks such as
btrfs and XFS
- Miscellaneous small changes to scripts and configuration files
* tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (47 commits)
modpost: Initialize builtin_modname to stop SIGSEGVs
Documentation: kbuild: note CONFIG_DEBUG_EFI in reproducible builds
kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o
modpost: Create modalias for builtin modules
modpost: Add modname to mod_device_table alias
scsi: Always define blogic_pci_tbl structure
kbuild: extract modules.builtin.modinfo from vmlinux.unstripped
kbuild: keep .modinfo section in vmlinux.unstripped
kbuild: always create intermediate vmlinux.unstripped
s390: vmlinux.lds.S: Reorder sections
KMSAN: Remove tautological checks
objtool: Drop noinstr hack for KCSAN_WEAK_MEMORY
lib/Kconfig.debug: Drop CLANG_VERSION check from DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
riscv: Remove ld.lld version checks from many TOOLCHAIN_HAS configs
riscv: Unconditionally use linker relaxation
riscv: Remove version check for LTO_CLANG selects
powerpc: Drop unnecessary initializations in __copy_inst_from_kernel_nofault()
mips: Unconditionally select ARCH_HAS_CURRENT_STACK_POINTER
arm64: Remove tautological LLVM Kconfig conditions
ARM: Clean up definition of ARM_HAS_GROUP_RELOCS
...
CONFIG_EFI_DEBUG embeds absolute file paths into object files, which
makes the resulting vmlinux specific to the build environment.
Add a note about this in reproducible-builds.rst
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nicolas Schier <nsc@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20250924-kbuild-doc-config-debug-efi-in-reproducible-builds-v2-1-d2d6b9dcdb7d@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
During kernel option migrations (e.g. CONFIG_CFI_CLANG to CONFIG_CFI),
existing .config files need to maintain backward compatibility while
preventing deprecated options from appearing in newly generated
configurations. This is challenging with existing Kconfig mechanisms
because:
1. Simply removing old options breaks existing .config files.
2. Manually listing an option as "deprecated" leaves it needlessly
visible and still writes them to new .config files.
3. Using any method to remove visibility (.e.g no 'prompt', 'if n',
etc) prevents the option from being processed at all.
Add a "transitional" attribute that creates symbols which are:
- Processed during configuration (can influence other symbols' defaults)
- Hidden from user menus (no prompts appear)
- Omitted from newly written .config files (gets migrated)
- Restricted to only having help sections (no defaults, selects, etc)
making it truly just a "prior value pass-through" option.
The transitional syntax requires a type argument and prevents type
redefinition:
config NEW_OPTION
bool "New option"
default OLD_OPTION
config OLD_OPTION
bool
transitional
help
Transitional config for OLD_OPTION migration.
This allows seamless migration: olddefconfig processes existing
CONFIG_OLD_OPTION=y settings to enable CONFIG_NEW_OPTION=y, while
CONFIG_OLD_OPTION is omitted from newly generated .config files.
Added positive and negative testing via "testconfig" make target.
Co-developed-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250923213422.1105654-2-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Add "alldefconfig" to the explanation of the KCONFIG_ALLCONFIG
environment variable usage so that all targets that use KCONFIG_ALLCONFIG
are listed.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which exports a
symbol only to specified modules
- Improve ABI handling in gendwarfksyms
- Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
- Add checkers for redundant or missing <linux/export.h> inclusion
- Deprecate the extra-y syntax
- Fix a genksyms bug when including enum constants from *.symref files
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Merge tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
exports a symbol only to specified modules
- Improve ABI handling in gendwarfksyms
- Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
- Add checkers for redundant or missing <linux/export.h> inclusion
- Deprecate the extra-y syntax
- Fix a genksyms bug when including enum constants from *.symref files
* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
genksyms: Fix enum consts from a reference affecting new values
arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
efi/libstub: use 'targets' instead of extra-y in Makefile
module: make __mod_device_table__* symbols static
scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
scripts/misc-check: check missing #include <linux/export.h> when W=1
scripts/misc-check: add double-quotes to satisfy shellcheck
kbuild: move W=1 check for scripts/misc-check to top-level Makefile
scripts/tags.sh: allow to use alternative ctags implementation
kconfig: introduce menu type enum
docs: symbol-namespaces: fix reST warning with literal block
kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
docs/core-api/symbol-namespaces: drop table of contents and section numbering
modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
kbuild: move kbuild syntax processing to scripts/Makefile.build
Makefile: remove dependency on archscripts for header installation
Documentation/kbuild: Add new gendwarfksyms kABI rules
Documentation/kbuild: Drop section numbers
...
KBUILD_BUILTIN is set to 1 unless you are building only modules.
KBUILD_MODULES is set to 1 when you are building only modules
(a typical use case is "make modules").
It is more useful to set them to 'y' instead, so we can do
something like:
always-$(KBUILD_BUILTIN) += vmlinux.lds
This works equivalently to:
extra-y += vmlinux.lds
This allows us to deprecate extra-y. extra-y and always-y are quite
similar, and we do not need both.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
x86 already uses gcc-8 as the minimum version, this changes all other
architectures to the same version. gcc-8 is used is Debian 10 and Red
Hat Enterprise Linux 8, both of which are still supported, and binutils
2.30 is the oldest corresponding version on those. Ubuntu Pro 18.04 and
SUSE Linux Enterprise Server 15 both use gcc-7 as the system compiler
but additionally include toolchains that remain supported.
With the new minimum toolchain versions, a number of workarounds for older
versions can be dropped, in particular on x86_64 and arm64. Importantly,
the updated compiler version allows removing two of the five remaining
gcc plugins, as support for sancov and structeak features is already
included in modern compiler versions.
I tried collecting the known changes that are possible based on the
new toolchain version, but expect that more cleanups will be possible.
Since this touches multiple architectures, I merged the patches through
the asm-generic tree.
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Merge tag 'gcc-minimum-version-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull compiler version requirement update from Arnd Bergmann:
"Require gcc-8 and binutils-2.30
x86 already uses gcc-8 as the minimum version, this changes all other
architectures to the same version. gcc-8 is used is Debian 10 and Red
Hat Enterprise Linux 8, both of which are still supported, and
binutils 2.30 is the oldest corresponding version on those.
Ubuntu Pro 18.04 and SUSE Linux Enterprise Server 15 both use gcc-7 as
the system compiler but additionally include toolchains that remain
supported.
With the new minimum toolchain versions, a number of workarounds for
older versions can be dropped, in particular on x86_64 and arm64.
Importantly, the updated compiler version allows removing two of the
five remaining gcc plugins, as support for sancov and structeak
features is already included in modern compiler versions.
I tried collecting the known changes that are possible based on the
new toolchain version, but expect that more cleanups will be possible.
Since this touches multiple architectures, I merged the patches
through the asm-generic tree."
* tag 'gcc-minimum-version-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
Makefile.kcov: apply needed compiler option unconditionally in CFLAGS_KCOV
Documentation: update binutils-2.30 version reference
gcc-plugins: remove SANCOV gcc plugin
Kbuild: remove structleak gcc plugin
arm64: drop binutils version checks
raid6: skip avx512 checks
kbuild: require gcc-8 and binutils-2.30
Document the "byte_size" and "type_string" kABI stability rules.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Change the gendwarfksyms documentation to use proper chapter,
section, and subsection adornments instead of fragile section
numbers.
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This reverts commit cacd22ce69.
-ffile-prefix-map breaks the ability of debuggers to find the source
file corresponding to object files. As there is no simple or uniform
way to specify the source directory explicitly, this breaks developers
workflows.
Revert the unconditional usage of -ffile-prefix-map.
Reported-by: Matthieu Baerts <matttbe@kernel.org>
Closes: https://lore.kernel.org/lkml/edc50aa7-0740-4942-8c15-96f12f2acc7e@kernel.org/
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Closes: https://lore.kernel.org/lkml/aBEttQH4kimHFScx@intel.com/
Fixes: cacd22ce69 ("kbuild: make all file references relative to source root")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Commit a3e8fe814a ("x86/build: Raise the minimum GCC version to 8.1")
raised the minimum compiler version as enforced by Kbuild to gcc-8.1
and clang-15 for x86.
This is actually the same gcc version that has been discussed as the
minimum for all architectures several times in the past, with little
objection. A previous concern was the kernel for SLE15-SP7 needing to
be built with gcc-7. As this ended up still using linux-6.4 and there
is no plan for an SP8, this is no longer a problem.
Change it for all architectures and adjust the documentation accordingly.
A few version checks can be removed in the process. The binutils
version 2.30 is the lowest version used in combination with gcc-8 on
common distros, so use that as the corresponding minimum.
Link: https://lore.kernel.org/lkml/20240925150059.3955569-32-ardb+git@google.com/
Link: https://lore.kernel.org/lkml/871q7yxrgv.wl-tiwai@suse.de/
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
-fmacro-prefix-map only affects __FILE__ and __BASE_FILE__.
Other references, for example in debug information, are not affected.
This makes handling of file references in the compiler outputs harder to
use and creates problems for reproducible builds.
Switch to -ffile-prefix map which affects all references.
Also drop the documentation section advising manual specification of
-fdebug-prefix-map for reproducible builds, as it is not necessary
anymore.
Suggested-by: Ben Hutchings <ben@decadent.org.uk>
Link: https://lore.kernel.org/lkml/c49cc967294f9a3a4a34f69b6a8727a6d3959ed8.camel@decadent.org.uk/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Correct the indentation in an example within the `modules.rst` file
to improve readability.
Signed-off-by: Kefan Liu <liukefan24s@ict.ac.cn>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Kernel build commands can sometimes be long, particularly when
cross-compiling, making them tedious to type and prone to mistypes.
This commit introduces bash completion support for common variables
and targets in Kbuild.
For installation instructions, please refer to the documentation in
Documentation/kbuild/bash-completion.rst.
The following examples demonstrate how this saves typing.
[Example 1] a long command line for cross-compiling
$ make A<TAB>
-> completes 'A' to 'ARCH='
$ make ARCH=<TAB>
-> displays all supported architectures
$ make ARCH=arm64 CR<TAB>
-> completes 'CR' to 'CROSS_COMPILE='
$ make ARCH=arm64 CROSS_COMPILE=<TAB>
-> displays installed toolchains
$ make ARCH=arm64 CROSS_COMPILE=aa<TAB>
-> completes 'CROSS_COMPILE=aa' to 'CROSS_COMPILE=aarch64-linux-gnu-'
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- def<TAB>
-> completes 'def' to 'defconfig'
[Example 2] a single build target
$ make f<TAB>
-> completes 'f' to 'fs/'
$ make fs/<TAB>
-> displays objects and sub-directories in fs/
$ make fs/xf<TAB>
-> completes 'fs/xf' to 'fs/xfs/'
$ make fs/xfs/l<TAB>
-> completes 'fs/xfs/l' to 'fs/xfs/libxfs/xfs_'
$ make fs/xfs/libxfs/xfs_g<TAB>
-> completes 'fs/xfs/libxfs/xfs_g' to 'fs/xfs/libxfs/xfs_group.o'
This does not aim to provide a complete list of variables and targets,
as there are too many. However, it covers variables and targets used
in common scenarios, and I hope this is useful enough.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Tested-by: Nicolas Schier <n.schier@avm.de>
Several drivers express optional Kconfig dependency with FOO || !FOO,
but for many choices this is not suitable: lack of stubs for !FOO
like in HWMON. Describe the second, less favorable way of optional
dependency with IS_REACHABLE by moving the code from "imply" chapter to
"Optional dependencies".
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Introduce `rustc-min-version` support function that mimics
`{gcc,clang}-min-version` ones, following commit 88b61e3bff
("Makefile.compiler: replace cc-ifversion with compiler-specific macros").
In addition, use it in the first use case we have in the kernel (which
was done independently to minimize the changes needed for the fix).
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Fiona Behrens <me@Kloenk.dev>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Commit f77bf01425 ("kbuild: introduce ccflags-y, asflags-y and
ldflags-y") deprecated these in 2007. The migration should have been
completed by now.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
- Support multiple hook locations for maint scripts of Debian package
- Remove 'cpio' from the build tool requirement
- Introduce gendwarfksyms tool, which computes CRCs for export symbols
based on the DWARF information
- Support CONFIG_MODVERSIONS for Rust
- Resolve all conflicts in the genksyms parser
- Fix several syntax errors in genksyms
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Merge tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Support multiple hook locations for maint scripts of Debian package
- Remove 'cpio' from the build tool requirement
- Introduce gendwarfksyms tool, which computes CRCs for export symbols
based on the DWARF information
- Support CONFIG_MODVERSIONS for Rust
- Resolve all conflicts in the genksyms parser
- Fix several syntax errors in genksyms
* tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (64 commits)
kbuild: fix Clang LTO with CONFIG_OBJTOOL=n
kbuild: Strip runtime const RELA sections correctly
kconfig: fix memory leak in sym_warn_unmet_dep()
kconfig: fix file name in warnings when loading KCONFIG_DEFCONFIG_LIST
genksyms: fix syntax error for attribute before init-declarator
genksyms: fix syntax error for builtin (u)int*x*_t types
genksyms: fix syntax error for attribute after 'union'
genksyms: fix syntax error for attribute after 'struct'
genksyms: fix syntax error for attribute after abstact_declarator
genksyms: fix syntax error for attribute before nested_declarator
genksyms: fix syntax error for attribute before abstract_declarator
genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier
genksyms: record attributes consistently for init-declarator
genksyms: restrict direct-declarator to take one parameter-type-list
genksyms: restrict direct-abstract-declarator to take one parameter-type-list
genksyms: remove Makefile hack
genksyms: fix last 3 shift/reduce conflicts
genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts
genksyms: reduce type_qualifier directly to decl_specifier
genksyms: rename cvar_qualifier to type_qualifier
...
These are flags to be passed when linking proc macros for the Rust
toolchain. If unset, it defaults to $(KBUILD_HOSTLDFLAGS).
This is needed because the list of flags to link hostprogs is not
necessarily the same as the list of flags used to link libmacros.so.
When we build proc macros, we need the latter, not the former (e.g. when
using a Rust compiler binary linked to a different C library than host
programs).
To distinguish between the two, introduce this new variable to stand
out from KBUILD_HOSTLDFLAGS used to link other host progs.
Signed-off-by: HONG Yifan <elsk@google.com>
Link: https://lore.kernel.org/r/20241017210430.2401398-2-elsk@google.com
[ v3:
- `export`ed the variable. Otherwise it would not be visible in
`rust/Makefile`.
- Removed "additional" from the documentation and commit message,
since this actually replaces the other flags, unlike other cases.
- Added example of use case to documentation and commit message.
Thanks Alice for the details on what Google needs!
- Instead of `HOSTLDFLAGS`, used `KBUILD_HOSTLDFLAGS` as the fallback
to preserve the previous behavior as much as possible, as discussed
with Alice/Yifan. Thus moved the variable down too (currently we
do not modify `KBUILD_HOSTLDFLAGS` elsewhere) and avoided
mentioning `HOSTLDFLAGS` directly in the documentation.
- Fixed documentation header formatting.
- Reworded slightly.
- Miguel ]
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: HONG Yifan <elsk@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20241112184455.855133-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Document where exported and imported symbols are kept, format options,
and limitations.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Add documentation for gendwarfksyms changes, and the kABI stability
features that can be useful for distributions even though they're not
used in mainline kernels.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
- Add generic support for built-in boot DTB files
- Enable TAB cycling for dialog buttons in nconfig
- Fix issues in streamline_config.pl
- Refactor Kconfig
- Add support for Clang's AutoFDO (Automatic Feedback-Directed
Optimization)
- Add support for Clang's Propeller, a profile-guided optimization.
- Change the working directory to the external module directory for M=
builds
- Support building external modules in a separate output directory
- Enable objtool for *.mod.o and additional kernel objects
- Use lz4 instead of deprecated lz4c
- Work around a performance issue with "git describe"
- Refactor modpost
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Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Add generic support for built-in boot DTB files
- Enable TAB cycling for dialog buttons in nconfig
- Fix issues in streamline_config.pl
- Refactor Kconfig
- Add support for Clang's AutoFDO (Automatic Feedback-Directed
Optimization)
- Add support for Clang's Propeller, a profile-guided optimization.
- Change the working directory to the external module directory for M=
builds
- Support building external modules in a separate output directory
- Enable objtool for *.mod.o and additional kernel objects
- Use lz4 instead of deprecated lz4c
- Work around a performance issue with "git describe"
- Refactor modpost
* tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits)
kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms
gitignore: Don't ignore 'tags' directory
kbuild: add dependency from vmlinux to resolve_btfids
modpost: replace tdb_hash() with hash_str()
kbuild: deb-pkg: add python3:native to build dependency
genksyms: reduce indentation in export_symbol()
modpost: improve error messages in device_id_check()
modpost: rename alias symbol for MODULE_DEVICE_TABLE()
modpost: rename variables in handle_moddevtable()
modpost: move strstarts() to modpost.h
modpost: convert do_usb_table() to a generic handler
modpost: convert do_of_table() to a generic handler
modpost: convert do_pnp_device_entry() to a generic handler
modpost: convert do_pnp_card_entries() to a generic handler
modpost: call module_alias_printf() from all do_*_entry() functions
modpost: pass (struct module *) to do_*_entry() functions
modpost: remove DEF_FIELD_ADDR_VAR() macro
modpost: deduplicate MODULE_ALIAS() for all drivers
modpost: introduce module_alias_printf() helper
modpost: remove unnecessary check in do_acpi_entry()
...
Unless an explicit O= option is provided, external module builds must
start from the kernel directory.
This can be achieved by using the -C option:
$ make -C /path/to/kernel M=/path/to/external/module
This commit allows starting external module builds from any directory,
so you can also do the following:
$ make -f /path/to/kernel/Makefile M=/path/to/external/module
The key difference is that the -C option changes the working directory
and parses the Makefile located there, while the -f option only
specifies the Makefile to use.
As shown in the examples in Documentation/kbuild/modules.rst, external
modules usually have a wrapper Makefile that allows you to build them
without specifying any make arguments. The Makefile typically contains
a rule as follows:
KDIR ?= /path/to/kernel
default:
$(MAKE) -C $(KDIR) M=$(CURDIR) $(MAKECMDGOALS)
The log will appear as follows:
$ make
make -C /path/to/kernel M=/path/to/external/module
make[1]: Entering directory '/path/to/kernel'
make[2]: Entering directory '/path/to/external/module'
CC [M] helloworld.o
MODPOST Module.symvers
CC [M] helloworld.mod.o
CC [M] .module-common.o
LD [M] helloworld.ko
make[2]: Leaving directory '/path/to/external/module'
make[1]: Leaving directory '/path/to/kernel'
This changes the working directory twice because the -C option first
switches to the kernel directory, and then Kbuild internally recurses
back to the external module directory.
With this commit, the wrapper Makefile can directly include the kernel
Makefile:
KDIR ?= /path/to/kernel
export KBUILD_EXTMOD := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
include $(KDIR)/Makefile
This avoids unnecessary sub-make invocations:
$ make
CC [M] helloworld.o
MODPOST Module.symvers
CC [M] helloworld.mod.o
CC [M] .module-common.o
LD [M] helloworld.ko
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
There has been a long-standing request to support building external
modules in a separate build directory.
This commit introduces a new environment variable, KBUILD_EXTMOD_OUTPUT,
and its shorthand Make variable, MO.
A simple usage:
$ make -C <kernel-dir> M=<module-src-dir> MO=<module-build-dir>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Currently, Kbuild always operates in the output directory of the kernel,
even when building external modules. This increases the risk of external
module Makefiles attempting to write to the kernel directory.
This commit switches the working directory to the external module
directory, allowing the removal of the $(KBUILD_EXTMOD)/ prefix from
some build artifacts.
The command for building external modules maintains backward
compatibility, but Makefiles that rely on working in the kernel
directory may break. In such cases, $(objtree) and $(srctree) should
be used to refer to the output and source directories of the kernel.
The appearance of the build log will change as follows:
[Before]
$ make -C /path/to/my/linux M=/path/to/my/externel/module
make: Entering directory '/path/to/my/linux'
CC [M] /path/to/my/externel/module/helloworld.o
MODPOST /path/to/my/externel/module/Module.symvers
CC [M] /path/to/my/externel/module/helloworld.mod.o
CC [M] /path/to/my/externel/module/.module-common.o
LD [M] /path/to/my/externel/module/helloworld.ko
make: Leaving directory '/path/to/my/linux'
[After]
$ make -C /path/to/my/linux M=/path/to/my/externel/module
make: Entering directory '/path/to/my/linux'
make[1]: Entering directory '/path/to/my/externel/module'
CC [M] helloworld.o
MODPOST Module.symvers
CC [M] helloworld.mod.o
CC [M] .module-common.o
LD [M] helloworld.ko
make[1]: Leaving directory '/path/to/my/externel/module'
make: Leaving directory '/path/to/my/linux'
Printing "Entering directory" twice is cumbersome. This will be
addressed later.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Since commit fde192511b ("kconfig: remove tristate choice support"),
all choice blocks are now boolean. There is no longer a need to specify
the choice type explicitly.
All "bool" prompts in choice entries have been converted to "prompt".
This commit removes support for the "bool" syntax in choice entries.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Avoid "gcc" since it is not the only compiler supported by Kbuild.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Building external modules is typically done using this command:
$ make -C <KERNEL_DIR> M=<EXTMOD_DIR>
Here, <KERNEL_DIR> refers to the output directory where the kernel was
built, not the kernel source directory.
When the kernel is built in the source tree, there is no ambiguity, as
the output directory and the source directory are the same.
If the kernel was built in a separate build directory, <KERNEL_DIR>
should be the kernel output directory. Otherwise, Kbuild cannot locate
necessary build artifacts. This has been the method for building
external modules against a pre-built kernel in a separate directory
for over 20 years. [1]
If you pass the kernel source directory to the -C option, you must also
specify the kernel build directory using the O= option. This approach
works as well, though it results in a slightly longer command:
$ make -C <KERNEL_SOURCE_DIR> O=<KERNEL_BUILD_DIR> M=<EXTMOD_DIR>
Some people mistakenly believe that O= should specify a build directory
for external modules when used together with M=. This commit adds more
clarification to Documentation/kbuild/kbuild.rst.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=e321b2ec2eb2993b3d0116e5163c78ad923e3c54
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
The use of shipped files is discouraged in the upstream kernel these
days. [1]
Downstream Makefiles have the freedom to use shipped files or other
options to handle binaries, but this should not be advertised in the
upstream document.
[1]: https://lore.kernel.org/all/CAHk-=wgSEi_ZrHdqr=20xv+d6dr5G895CbOAi8ok+7-CQUN=fQ@mail.gmail.com/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Do similar to commit 1a4c1c9df7 ("docs/kbuild/makefiles: drop section
numbering, use references").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Do similar to commit 5e8f0ba38a ("docs/kbuild/makefiles: throw out the
local table of contents").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Kbuild used to manipulate header search paths, enforcing the odd
limitation of "no space after -I".
Commit cdd750bfb1 ("kbuild: remove 'addtree' and 'flags' magic for
header search paths") stopped doing that. This limitation no longer
exists. Instead, you need to accurately specify the header search path.
(In this case, $(src)/include)
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
The phrase "In newer versions of the kernel" was added 14 years ago, by
commit efdf02cf06 ("Documentation/kbuild: major edit of modules.txt
sections 1-4"). This feature is no longer new, so remove it and update
the paragraph.
Example 3 was written 20 years ago [1]. There is no need to note about
backward compatibility with such an old build system. Remove Example 3
entirely.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=65e433436b5794ae056d22ddba60fe9194bba007
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Create file module.builtin.ranges that can be used to find where
built-in modules are located by their addresses. This will be useful for
tracing tools to find what functions are for various built-in modules.
The offset range data for builtin modules is generated using:
- modules.builtin: associates object files with module names
- vmlinux.map: provides load order of sections and offset of first member
per section
- vmlinux.o.map: provides offset of object file content per section
- .*.cmd: build cmd file with KBUILD_MODFILE
The generated data will look like:
.text 00000000-00000000 = _text
.text 0000baf0-0000cb10 amd_uncore
.text 0009bd10-0009c8e0 iosf_mbi
...
.text 00b9f080-00ba011a intel_skl_int3472_discrete
.text 00ba0120-00ba03c0 intel_skl_int3472_discrete intel_skl_int3472_tps68470
.text 00ba03c0-00ba08d6 intel_skl_int3472_tps68470
...
.data 00000000-00000000 = _sdata
.data 0000f020-0000f680 amd_uncore
For each ELF section, it lists the offset of the first symbol. This can
be used to determine the base address of the section at runtime.
Next, it lists (in strict ascending order) offset ranges in that section
that cover the symbols of one or more builtin modules. Multiple ranges
can apply to a single module, and ranges can be shared between modules.
The CONFIG_BUILTIN_MODULE_RANGES option controls whether offset range data
is generated for kernel modules that are built into the kernel image.
How it works:
1. The modules.builtin file is parsed to obtain a list of built-in
module names and their associated object names (the .ko file that
the module would be in if it were a loadable module, hereafter
referred to as <kmodfile>). This object name can be used to
identify objects in the kernel compile because any C or assembler
code that ends up into a built-in module will have the option
-DKBUILD_MODFILE=<kmodfile> present in its build command, and those
can be found in the .<obj>.cmd file in the kernel build tree.
If an object is part of multiple modules, they will all be listed
in the KBUILD_MODFILE option argument.
This allows us to conclusively determine whether an object in the
kernel build belong to any modules, and which.
2. The vmlinux.map is parsed next to determine the base address of each
top level section so that all addresses into the section can be
turned into offsets. This makes it possible to handle sections
getting loaded at different addresses at system boot.
We also determine an 'anchor' symbol at the beginning of each
section to make it possible to calculate the true base address of
a section at runtime (i.e. symbol address - symbol offset).
We collect start addresses of sections that are included in the top
level section. This is used when vmlinux is linked using vmlinux.o,
because in that case, we need to look at the vmlinux.o linker map to
know what object a symbol is found in.
And finally, we process each symbol that is listed in vmlinux.map
(or vmlinux.o.map) based on the following structure:
vmlinux linked from vmlinux.a:
vmlinux.map:
<top level section>
<included section> -- might be same as top level section)
<object> -- built-in association known
<symbol> -- belongs to module(s) object belongs to
...
vmlinux linked from vmlinux.o:
vmlinux.map:
<top level section>
<included section> -- might be same as top level section)
vmlinux.o -- need to use vmlinux.o.map
<symbol> -- ignored
...
vmlinux.o.map:
<section>
<object> -- built-in association known
<symbol> -- belongs to module(s) object belongs to
...
3. As sections, objects, and symbols are processed, offset ranges are
constructed in a straight-forward way:
- If the symbol belongs to one or more built-in modules:
- If we were working on the same module(s), extend the range
to include this object
- If we were working on another module(s), close that range,
and start the new one
- If the symbol does not belong to any built-in modules:
- If we were working on a module(s) range, close that range
Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Sam James <sam@gentoo.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
There are a few lines in the kbuild-language.rst document which
obliquely reference the behavior of config options without prompts.
But there is nothing in the obvious location that explicitly calls
out that users cannot edit config options unless they have a prompt.
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The command provided to use ccache with clang is not a literal code
block. Once built, the documentation displays the '' symbols as a "
character, which is wrong, and the command can not be applied as
provided.
Turn the command into a literal code block.
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
In this part of the documentation, $(CC) is meant, but gcc is written.
Signed-off-by: Ivan Davydov <davydoff33@yandex.ru>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
I previously submitted a fix for a bug in the choice feature [1], where
I mentioned, "Another (much cleaner) approach would be to remove the
tristate choice support entirely".
There are more issues in the tristate choice feature. For example, you
can observe a couple of bugs in the following test code.
[Test Code]
config MODULES
def_bool y
modules
choice
prompt "tristate choice"
default A
config A
tristate "A"
config B
tristate "B"
endchoice
Bug 1: the 'default' property is not correctly processed
'make alldefconfig' produces:
CONFIG_MODULES=y
# CONFIG_A is not set
# CONFIG_B is not set
However, the correct output should be:
CONFIG_MODULES=y
CONFIG_A=y
# CONFIG_B is not set
The unit test file, scripts/kconfig/tests/choice/alldef_expected_config,
is wrong as well.
Bug 2: choice members never get 'y' with randconfig
For the test code above, the following combinations are possible:
A B
(1) y n
(2) n y
(3) m m
(4) m n
(5) n m
(6) n n
'make randconfig' never produces (1) or (2).
These bugs are fixable, but a more critical problem is the lack of a
sensible syntax to specify the default for the tristate choice.
The default for the choice must be one of the choice members, which
cannot specify any of the patterns (3) through (6) above.
In addition, I have never seen it being used in a useful way.
The following commits removed unnecessary use of tristate choices:
- df8df5e4bc ("usb: get rid of 'choice' for legacy gadget drivers")
- bfb57ef054 ("rapidio: remove choice for enumeration")
This commit removes the tristate choice support entirely, which allows
me to delete a lot of code, making further refactoring easier.
Note:
This includes the revert of commit fa64e5f6a3 ("kconfig/symbol.c:
handle choice_values that depend on 'm' symbols"). It was suspicious
because it did not address the root cause but introduced inconsistency
in visibility between choice members and other symbols.
[1]: https://lore.kernel.org/linux-kbuild/20240427104231.2728905-1-masahiroy@kernel.org/T/#m0a1bb6992581462ceca861b409bb33cb8fd7dbae
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
The default INSTALL_MOD_DIR was changed from 'extra' to
'updates' in commit b74d7bb7ca ("kbuild: Modify default
INSTALL_MOD_DIR from extra to updates").
This commit updates the documentation to align with the
latest kernel.
Fixes: b74d7bb7ca ("kbuild: Modify default INSTALL_MOD_DIR from extra to updates")
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
