diff options
| author | Mark Brown <broonie@kernel.org> | 2026-10-30 10:59:17 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2026-10-30 10:59:17 +0000 |
| commit | c56685eb76c7bd9b38ab4fe2c1ebfebc8bf83104 (patch) | |
| tree | 7014bc8e5603448418a0f673cfc354d6af854ab1 | |
| parent | b76eb7c1d52e4b26ad6db30fc90b5d81d1fe6455 (diff) | |
| parent | 83deedcf85af511dc120b3cd8ee597d211cdf2fb (diff) | |
| download | linux-next-c56685eb76c7bd9b38ab4fe2c1ebfebc8bf83104.tar.gz linux-next-c56685eb76c7bd9b38ab4fe2c1ebfebc8bf83104.zip | |
Merge branch 'kbuild-fixes-for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux.git
| -rw-r--r-- | Makefile | 3 | ||||
| -rw-r--r-- | scripts/Kconfig.toolchain | 23 |
2 files changed, 21 insertions, 5 deletions
@@ -1059,7 +1059,8 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT endif endif ifdef CONFIG_HAVE_FENTRY - ifdef CONFIG_CC_HAS_MFENTRY + # s390-linux-gnu-gcc did not support -mfentry until gcc-9. + ifeq ($(call cc-option-yn, -mfentry),y) CC_FLAGS_FTRACE += -mfentry CC_FLAGS_USING += -DCC_USING_FENTRY endif diff --git a/scripts/Kconfig.toolchain b/scripts/Kconfig.toolchain index 4b962831d62a..2acbd40a38f1 100644 --- a/scripts/Kconfig.toolchain +++ b/scripts/Kconfig.toolchain @@ -144,6 +144,25 @@ config CC_HAS_ASSUME config CC_HAS_NO_PROFILE_FN_ATTR def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) +# Beware of two problems when using cc-option in Kconfig compared to Kbuild +# +# 1. cc-option in Kbuild tests the provided flags with all previously added +# CFLAGS, whereas cc-option in Kconfig only tests the provided flags with a +# small, constant set of additional flags. If a flag (e.g., '-mfoo') +# depends on another (e.g, '-fbar') to function properly, the dependency +# must be included in the cc-option call (e.g, '-fbar -mfoo'). +# +# 2. Bit and endianness flags ('-m32', '-m64', '-mbig-endian', and +# '-mlittle-endian') are not present in Kconfig cc-option checks because +# they may be included in KBUILD_CFLAGS / KBUILD_CPPFLAGS based on the +# finalized configuration result. This can result in inconsistent results +# when probing toolchains that support either option, as the toolchain's +# configured default tested in Kconfig may not support the tested flag but +# the post-configuration result in Kbuild would. +# +# In general, prefer adding truly generic compiler flags to avoid this +# pitfall. + config CC_OPT_ZERO_INIT_PADDING_BITS def_string "$(cc-option-str,-fzero-init-padding-bits=all)" @@ -169,10 +188,6 @@ config CC_OPT_NO_ALLOW_STORE_DATA_RACES config CC_HAS_MNOP_MCOUNT def_bool $(cc-option,-mnop-mcount) -# s390-linux-gnu-gcc did not support -mfentry until gcc-9. -config CC_HAS_MFENTRY - def_bool $(cc-option,-mfentry) - config LD_OPT_FORCE_GROUP_ALLOCATION def_string "$(ld-option-str,--force-group-allocation)" |