user/sven/linux.git/scripts/Makefile.extrawarn, branch v6.9.2

kbuild: make -Woverride-init warnings more consistent

2024-03-31T02:32:26Z

The -Woverride-init warn about code that may be intentional or not, but the inintentional ones tend to be real bugs, so there is a bit of disagreement on whether this warning option should be enabled by default and we have multiple settings in scripts/Makefile.extrawarn as well as individual subsystems. Older versions of clang only supported -Wno-initializer-overrides with the same meaning as gcc's -Woverride-init, though all supported versions now work with both. Because of this difference, an earlier cleanup of mine accidentally turned the clang warning off for W=1 builds and only left it on for W=2, while it's still enabled for gcc with W=1. There is also one driver that only turns the warning off for newer versions of gcc but not other compilers, and some but not all the Makefiles still use a cc-disable-warning conditional that is no longer needed with supported compilers here. Address all of the above by removing the special cases for clang and always turning the warning off unconditionally where it got in the way, using the syntax that is supported by both compilers. Fixes: 2cd3271b7a31 ("kbuild: avoid duplicate warning options") Signed-off-by: Arnd Bergmann Acked-by: Hamza Mahfooz Acked-by: Jani Nikula Acked-by: Andrew Jeffery Signed-off-by: Jani Nikula Reviewed-by: Linus Walleij Signed-off-by: Masahiro Yamada

kbuild: remove GCC's default -Wpacked-bitfield-compat flag

2024-03-11T08:31:41Z

Commit 4a5838ad9d2d ("kbuild: Add extra gcc checks") added the -Wpacked-bitfield-compat flag, but there is no need to add it explicitly. GCC manual says: "This warning is enabled by default. Use -Wno-packed-bitfield-compat to disable this warning." The test code in the manual: struct foo { char a:4; char b:8; } __attribute__ ((packed)); ... emits "note: offset of packed bit-field ‘b’ has changed in GCC 4.4" without W=3. Let's remove it, as it is a default with GCC. Clang does not support this flag, so its removal will not affect Clang builds. Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor

kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1

2024-03-10T08:27:17Z

Clang enables -Wenum-enum-conversion and -Wenum-compare-conditional under -Wenum-conversion. A recent change in Clang strengthened these warnings and they appear frequently in common builds, primarily due to several instances in common headers but there are quite a few drivers that have individual instances as well. include/linux/vmstat.h:508:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion] 508 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS + | ~~~~~~~~~~~~~~~~~~~~~ ^ 509 | item]; | ~~~~ drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c:955:24: warning: conditional expression between different enumeration types ('enum iwl_mac_beacon_flags' and 'enum iwl_mac_beacon_flags_v1') [-Wenum-compare-conditional] 955 | flags |= is_new_rate ? IWL_MAC_BEACON_CCK | ^ ~~~~~~~~~~~~~~~~~~ 956 | : IWL_MAC_BEACON_CCK_V1; | ~~~~~~~~~~~~~~~~~~~~~ drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c:1120:21: warning: conditional expression between different enumeration types ('enum iwl_mac_beacon_flags' and 'enum iwl_mac_beacon_flags_v1') [-Wenum-compare-conditional] 1120 | 0) > 10 ? | ^ 1121 | IWL_MAC_BEACON_FILS : | ~~~~~~~~~~~~~~~~~~~ 1122 | IWL_MAC_BEACON_FILS_V1; | ~~~~~~~~~~~~~~~~~~~~~~ Doing arithmetic between or returning two different types of enums could be a bug, so each of the instance of the warning needs to be evaluated. Unfortunately, as mentioned above, there are many instances of this warning in many different configurations, which can break the build when CONFIG_WERROR is enabled. To avoid introducing new instances of the warnings while cleaning up the disruption for the majority of users, disable these warnings for the default build while leaving them on for W=1 builds. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2002 Link: https://github.com/llvm/llvm-project/commit/8c2ae42b3e1c6aa7c18f873edcebff7c0b45a37e Acked-by: Yonghong Song Signed-off-by: Nathan Chancellor Acked-by: Arnd Bergmann Signed-off-by: Masahiro Yamada

Makefile: Enable -Wstringop-overflow globally

2024-01-21T23:45:31Z

It seems that we have finished addressing all the remaining issues regarding -Wstringop-overflow. So, we are now in good shape to enable this compiler option globally. Signed-off-by: Gustavo A. R. Silva

Merge tag 'kbuild-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2024-01-19T01:57:07Z

Pull Kbuild updates from Masahiro Yamada: - Make Kconfig parse the input .config more precisely - Support W=c and W=e options for Kconfig - Set Kconfig int/hex symbols to zero if the 'default' property is missing - Add .editorconfig - Add scripts/git.orderFile - Add a script to detect backward-incompatible changes in UAPI headers - Resolve the symlink passed to O= option properly - Use the user-supplied mtime for all files in the builtin initramfs, which provides better reproducible builds - Fix the direct execution of debian/rules for Debian package builds - Use build ID instead of the .gnu_debuglink section for the Debian dbg package * tag 'kbuild-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (53 commits) kbuild: deb-pkg: use debian/ for tmpdir kbuild: deb-pkg: move 'make headers' to build-arch kbuild: deb-pkg: do not search for 'scripts' directory under arch/ kbuild: deb-pkg: use build ID instead of debug link for dbg package kbuild: deb-pkg: use more debhelper commands in builddeb kbuild: deb-pkg: remove unneeded '-f $srctree/Makefile' in debian/rules kbuild: deb-pkg: allow to run debian/rules from output directory kbuild: deb-pkg: set DEB_* variables if debian/rules is directly executed kbuild: deb-pkg: squash scripts/package/deb-build-option to debian/rules kbuild: deb-pkg: factor out common Make options in debian/rules kbuild: deb-pkg: hard-code Build-Depends kbuild: deb-pkg: split debian/copyright from the mkdebian script gen_init_cpio: Apply mtime supplied by user to all file types kbuild: resolve symlinks for O= properly docs: dev-tools: Add UAPI checker documentation check-uapi: Introduce check-uapi.sh scripts: Introduce a default git.orderFile kconfig: WERROR unmet symbol dependency Add .editorconfig file for basic formatting kconfig: Use KCONFIG_CONFIG instead of .config ...

Makefile.extrawarn: turn on missing-prototypes globally

2023-12-20T23:02:57Z

Over the years we went from > 1000 of warnings to under 100 earlier this year, and I sent patches to address all the ones that I saw with compile testing randcom configs on arm64, arm and x86 kernels. This is a really useful warning, as it catches real bugs when there are mismatched prototypes. In particular with kernel control flow integrity enabled, those are no longer allowed. I have done extensive testing to ensure that there are no new build errors or warnings on any configuration of x86, arm and arm64 builds. I also made sure that at least both the normal defconfig and an allmodconfig build is clean for arc, csky, loongarch, m68k, microblaze, openrisc, parisc, powerpc, riscv, s390, and xtensa, with the respective maintainers doing most of the patches. At this point, there are five architectures with a number of known regressions: alpha, nios2, mips, sh and sparc. In the previous version of this patch, I had turned off the missing prototype warnings for the 15 architectures that still had issues, but since there are only five left, I think we can leave the rest to the maintainers (Cc'd here) as well. Link: https://lkml.kernel.org/r/20231123110506.707903-7-arnd@kernel.org Link: https://lore.kernel.org/lkml/20230810141947.1236730-1-arnd@kernel.org/ Signed-off-by: Arnd Bergmann Reviewed-by: Kees Cook Acked-by: Palmer Dabbelt # RISC-V Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Dinh Nguyen Cc: Thomas Bogendoerfer Cc: Yoshinori Sato Cc: Rich Felker Cc: John Paul Adrian Glaubitz Cc: "David S. Miller" Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Masahiro Yamada Cc: Michael Ellerman Cc: Nathan Chancellor Cc: Nicolas Schier Cc: Peter Zijlstra Cc: Richard Weinberger Cc: Stephen Rothwell Cc: Tudor Ambarus Cc: Zhihao Cheng Signed-off-by: Andrew Morton

kbuild: support W=c and W=e shorthands for Kconfig

2023-12-03T09:50:48Z

KCONFIG_WARN_UNKNOWN_SYMBOLS=1 and KCONFIG_WERROR=1 are descriptive and suitable in scripting, but typing them from the command line can be tedious. Associate them with KBUILD_EXTRA_WARN (and the W= shorthand). Support a new letter 'c' to enable extra checks in Kconfig. You can still manage compiler warnings (W=1) and Kconfig warnings (W=c) independently. Reuse the letter 'e' to turn Kconfig warnings into errors. As usual, you can combine multiple letters in KCONFIG_EXTRA_WARN. $ KCONFIG_WARN_UNKNOWN_SYMBOLS=1 KCONFIG_WERROR=1 make defconfig can be shortened to: $ KBUILD_EXTRA_WARN=ce make defconfig or, even shorter: $ make W=ce defconfig Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor

extrawarn: move -Wrestrict into W=1 warnings

2023-08-20T05:16:59Z

There are few of these, so enable them whenever W=1 is enabled. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada

extrawarn: enable format and stringop overflow warnings in W=1

2023-08-20T05:16:59Z

The stringop and format warnings got disabled globally when they were newly introduced in commit bd664f6b3e376 ("disable new gcc-7.1.1 warnings for now"), 217c3e0196758 ("disable stringop truncation warnings for now") and 5a76021c2eff7 ("gcc-10: disable 'stringop-overflow' warning for now"). In all cases, the sentiment at the time was that the warnings are useful, and we actually addressed a number of real bugs based on them, but we never managed to eliminate them all because even the build bots using W=1 builds only see the -Wstringop-truncation warnings that are enabled at that level. Move these into the W=1 section to give them a larger build coverage and actually eliminate them over time. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada

kbuild: avoid duplicate warning options

2023-08-20T05:16:57Z

Some warning options are disabled at one place and then conditionally re-enabled later in scripts/Makefile.extrawarn. For consistency, rework this file so each of those warnings only gets etiher enabled or disabled based on the W= flags but not both. Signed-off-by: Arnd Bergmann Signed-off-by: Masahiro Yamada