On Sat 17 Feb 2024 14:55:03 GMT, Masahiro Yamada wrote:
> Commit 54b8ae66ae1a ("kbuild: change *FLAGS_<basetarget>.o to take the
> path relative to $(obj)") changed the syntax of per-file compiler flags.
>
> The situation is the same for the following variables:
>
> OBJECT_FILES_NON_STANDARD_<basetarget>.o
> GCOV_PROFILE_<basetarget>.o
> KASAN_SANITIZE_<basetarget>.o
> KMSAN_SANITIZE_<basetarget>.o
> KMSAN_ENABLE_CHECKS_<basetarget>.o
> UBSAN_SANITIZE_<basetarget>.o
> KCOV_INSTRUMENT_<basetarget>.o
> KCSAN_SANITIZE_<basetarget>.o
> KCSAN_INSTRUMENT_BARRIERS_<basetarget>.o
>
> The <basetarget> is the filename of the target with its directory and
> suffix stripped.
>
> This syntax comes into a trouble when two files with the same basename
> appear in one Makefile, for example:
>
> obj-y += dir1/foo.o
> obj-y += dir2/foo.o
> OBJECT_FILES_NON_STANDARD_foo.o := y
>
> OBJECT_FILES_NON_STANDARD_foo.o is applied to both dir1/foo.o and
> dir2/foo.o. This syntax is not flexbile enough to handle cases where
> one of them is a standard object, but the other is not.
>
> It is more sensible to use the relative path to the Makefile, like this:
>
> obj-y += dir1/foo.o
> OBJECT_FILES_NON_STANDARD_dir1/foo.o := y
> obj-y += dir2/foo.o
> OBJECT_FILES_NON_STANDARD_dir2/foo.o := y
>
> To maintain the current behavior, I made adjustments to two Makefiles:
>
> - arch/x86/entry/vdso/Makefile, which compiles vclock_gettime.o and
> vdso32/vclock_gettime.o
>
> - arch/x86/kvm/Makefile, which compiles vmx/vmenter.o and svm/vmenter.o
>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
> arch/x86/entry/vdso/Makefile | 2 ++
> arch/x86/kvm/Makefile | 3 ++-
> scripts/Makefile.build | 2 +-
> scripts/Makefile.lib | 16 ++++++++--------
> 4 files changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
> index 7a97b17f28b7..148adfdb2325 100644
> --- a/arch/x86/entry/vdso/Makefile
> +++ b/arch/x86/entry/vdso/Makefile
> @@ -9,7 +9,9 @@ include $(srctree)/lib/vdso/Makefile
> # Sanitizer runtimes are unavailable and cannot be linked here.
> KASAN_SANITIZE := n
> KMSAN_SANITIZE_vclock_gettime.o := n
> +KMSAN_SANITIZE_vdso32/vclock_gettime.o := n
> KMSAN_SANITIZE_vgetcpu.o := n
> +KMSAN_SANITIZE_vdso32/vgetcpu.o := n
>
> UBSAN_SANITIZE := n
> KCSAN_SANITIZE := n
> diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
> index 475b5fa917a6..a88bb14266b6 100644
> --- a/arch/x86/kvm/Makefile
> +++ b/arch/x86/kvm/Makefile
> @@ -4,7 +4,8 @@ ccflags-y += -I $(srctree)/arch/x86/kvm
> ccflags-$(CONFIG_KVM_WERROR) += -Werror
>
> ifeq ($(CONFIG_FRAME_POINTER),y)
> -OBJECT_FILES_NON_STANDARD_vmenter.o := y
> +OBJECT_FILES_NON_STANDARD_vmx/vmenter.o := y
> +OBJECT_FILES_NON_STANDARD_svm/vmenter.o := y
> endif
>
> include $(srctree)/virt/kvm/Makefile.kvm
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 4971f54c855e..256db2a0e984 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -214,7 +214,7 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
> # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
> # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
>
> -is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
> +is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),y)
>
> $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
>
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index b35d39022a30..328c0d77ed48 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -154,7 +154,7 @@ _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
> #
> ifeq ($(CONFIG_GCOV_KERNEL),y)
> _c_flags += $(if $(patsubst n%,, \
> - $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
> + $(GCOV_PROFILE_$(target-stem).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
> $(CFLAGS_GCOV))
> endif
>
> @@ -165,29 +165,29 @@ endif
> ifeq ($(CONFIG_KASAN),y)
> ifneq ($(CONFIG_KASAN_HW_TAGS),y)
> _c_flags += $(if $(patsubst n%,, \
> - $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
> + $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)y), \
> $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
> endif
> endif
>
> ifeq ($(CONFIG_KMSAN),y)
> _c_flags += $(if $(patsubst n%,, \
> - $(KMSAN_SANITIZE_$(basetarget).o)$(KMSAN_SANITIZE)y), \
> + $(KMSAN_SANITIZE_$(target-stem).o)$(KMSAN_SANITIZE)y), \
> $(CFLAGS_KMSAN))
> _c_flags += $(if $(patsubst n%,, \
> - $(KMSAN_ENABLE_CHECKS_$(basetarget).o)$(KMSAN_ENABLE_CHECKS)y), \
> + $(KMSAN_ENABLE_CHECKS_$(target-stem).o)$(KMSAN_ENABLE_CHECKS)y), \
> , -mllvm -msan-disable-checks=1)
> endif
>
> ifeq ($(CONFIG_UBSAN),y)
> _c_flags += $(if $(patsubst n%,, \
> - $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
> + $(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
> $(CFLAGS_UBSAN))
> endif
>
> ifeq ($(CONFIG_KCOV),y)
> _c_flags += $(if $(patsubst n%,, \
> - $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
> + $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
> $(CFLAGS_KCOV))
> endif
>
> @@ -197,12 +197,12 @@ endif
> #
> ifeq ($(CONFIG_KCSAN),y)
> _c_flags += $(if $(patsubst n%,, \
> - $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \
> + $(KCSAN_SANITIZE_$(target-stem).o)$(KCSAN_SANITIZE)y), \
> $(CFLAGS_KCSAN))
> # Some uninstrumented files provide implied barriers required to avoid false
> # positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.
> _c_flags += $(if $(patsubst n%,, \
> - $(KCSAN_INSTRUMENT_BARRIERS_$(basetarget).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
> + $(KCSAN_INSTRUMENT_BARRIERS_$(target-stem).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
> -D__KCSAN_INSTRUMENT_BARRIERS__)
> endif
>
> --
> 2.40.1
>
Looks good to me!
Reviewed-by: Nicolas Schier <nicolas@xxxxxxxxx>
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