On Tue, Nov 19, 2024 at 04:24:41AM +0000, Sam James wrote: > This is the conclusion I just reached, although I'm struggling to figure > out a nice place to put it without sprinkling it all over the place. I'm > inclined to wait until kbuild folks weigh in so I don't do a lot of > (trivial, but tedious) work that needs changing. Sure. Masahiro, do you have any thoughts here? You can see the beginning of the thread at [1]. I think the diff below would be a good first patch in a series that adds it to every other place that needs it. As you noticed, it probably makes sense to add it to most places that have CLANG_FLAGS, as that is a good indicator that KBUILD_CFLAGS is not being used properly in those spots. > As a hack, I've injected it into CLANG_FLAGS locally for now as it > happens to appear in all the right places ;) :) exactly why I am quite familiar with this issue... [1]: https://lore.kernel.org/4OAhbllK7x4QJGpZjkYjtBYNLd_2whHx9oFiuZcGwtVR4hIzvduultkgfAIRZI3vQpZylu7Gl929HaYFRGeMEalWCpeMzCIIhLxxRhq4U-Y=@protonmail.com/ Cheers, Nathan diff --git a/Makefile b/Makefile index 68a8faff2543..33cc6bcf39b5 100644 --- a/Makefile +++ b/Makefile @@ -416,6 +416,8 @@ export KCONFIG_CONFIG # SHELL used by kbuild CONFIG_SHELL := sh +CSTD_FLAG := -std=gnu11 + HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null) HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null) HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null) @@ -437,7 +439,7 @@ HOSTRUSTC = rustc HOSTPKG_CONFIG = pkg-config KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ - -O2 -fomit-frame-pointer -std=gnu11 + -O2 -fomit-frame-pointer $(CSTD_FLAG) KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS) KBUILD_USERLDFLAGS := $(USERLDFLAGS) @@ -545,7 +547,7 @@ LINUXINCLUDE := \ KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE KBUILD_CFLAGS := -KBUILD_CFLAGS += -std=gnu11 +KBUILD_CFLAGS += $(CSTD_FLAG) KBUILD_CFLAGS += -fshort-wchar KBUILD_CFLAGS += -funsigned-char KBUILD_CFLAGS += -fno-common @@ -589,7 +591,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE -export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS CSTD_FLAG export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 25a2cb6317f3..5f9d5c38ed9e 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -65,7 +65,7 @@ VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ -fno-strict-aliasing -fno-common \ -Werror-implicit-function-declaration \ -Wno-format-security \ - -std=gnu11 + $(CSTD_FLAG) VDSO_CFLAGS += -O2 # Some useful compiler-dependent flags from top-level Makefile VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 5b773b34768d..d5c851dd0653 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -47,7 +47,7 @@ endif # How to compile the 16-bit code. Note we always compile for -march=i386; # that way we can complain to the user if the CPU is insufficient. -REALMODE_CFLAGS := -std=gnu11 -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ +REALMODE_CFLAGS := $(CSTD_FLAG) -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \ -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)
