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author | Masahiro Yamada <masahiroy@kernel.org> | 2024-04-28 00:32:53 +0900 |
---|---|---|
committer | Masahiro Yamada <masahiroy@kernel.org> | 2024-05-10 04:34:52 +0900 |
commit | d98dba8852592402b67b643015f64b394760daa9 (patch) | |
tree | 89053eef2f4ab7df4a629e2d922ee0452bf10dc4 /scripts | |
parent | 770202a2233f819bfc33844d860e7282e696a91c (diff) |
kbuild: add 'private' to target-specific variables
Currently, Kbuild produces inconsistent results in some cases.
You can do an interesting experiment using the --shuffle option, which
is supported by GNU Make 4.4 or later.
Set CONFIG_KVM_INTEL=y and CONFIG_KVM_AMD=m (or vice versa), and repeat
incremental builds w/wo --shuffle=reverse.
$ make
[ snip ]
CC arch/x86/kvm/kvm-asm-offsets.s
$ make --shuffle=reverse
[ snip ]
CC [M] arch/x86/kvm/kvm-asm-offsets.s
$ make
[ snip ]
CC arch/x86/kvm/kvm-asm-offsets.s
arch/x86/kvm/kvm-asm-offsets.s is rebuilt every time w/wo the [M] marker.
arch/x86/kvm/kvm-asm-offsets.s is built as built-in when it is built as
a prerequisite of arch/x86/kvm/kvm-intel.o, which is built-in.
arch/x86/kvm/kvm-asm-offsets.s is built as modular when it is built as
a prerequisite of arch/x86/kvm/kvm-amd.o, which is a module.
Another odd example is single target builds.
When CONFIG_LKDTM=m, drivers/misc/lkdtm/rodata.o can be built as
built-in or modular, depending on how it is built.
$ make drivers/misc/lkdtm/lkdtm.o
[ snip ]
CC [M] drivers/misc/lkdtm/rodata.o
$ make drivers/misc/lkdtm/rodata.o
[ snip ]
CC drivers/misc/lkdtm/rodata.o
drivers/misc/lkdtm/rodata.o is built as modular when it is built as a
prerequisite of another, but built as built-in when it is a final
target.
The same thing happens to drivers/memory/emif-asm-offsets.s when
CONFIG_TI_EMIF_SRAM=m.
$ make drivers/memory/ti-emif-sram.o
[ snip ]
CC [M] drivers/memory/emif-asm-offsets.s
$ make drivers/memory/emif-asm-offsets.s
[ snip ]
CC drivers/memory/emif-asm-offsets.s
This is because the part-of-module=y flag defined for the modules is
inherited by its prerequisites.
Target-specific variables are likely intended only for local use.
This commit adds 'private' to them.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Diffstat (limited to 'scripts')
-rw-r--r-- | scripts/Makefile.build | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 43b71c3d0ff6..c9c07a6144eb 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -216,7 +216,7 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT 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)) +$(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y)) ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi))) @@ -437,8 +437,8 @@ define rule_ld_multi_m $(call cmd,gen_objtooldep) endef -$(multi-obj-m): objtool-enabled := $(delay-objtool) -$(multi-obj-m): part-of-module := y +$(multi-obj-m): private objtool-enabled := $(delay-objtool) +$(multi-obj-m): private part-of-module := y $(multi-obj-m): %.o: %.mod FORCE $(call if_changed_rule,ld_multi_m) $(call multi_depend, $(multi-obj-m), .o, -objs -y -m) |