Re: [PATCH v2 03/13] kbuild: store the objtool command in *.cmd files
From: Nick Desaulniers <hidden>
Date: 2021-08-31 17:23:28
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On Tue, Aug 31, 2021 at 12:40 AM Masahiro Yamada [off-list ref] wrote:
objtool_dep includes include/config/{ORC_UNWINDER,STACK_VALIDATION}
so that all the objects are rebuilt when any of CONFIG_ORC_UNWINDER
and CONFIG_STACK_VALIDATION is toggled.
As you can see in 'objtool_args', there are more CONFIG options
that affect the objtool command line.
Adding more and more include/config/* is ugly and unmaintainable.
Another issue is that non-standard objects are needlessly rebuilt.
Objects specified as OBJECT_FILES_NON_STANDARD is not processed by
objtool, but they are rebuilt anyway when CONFIG_ORC_UNWINDER or
CONFIG_STACK_VALIDATION is toggled. This is not a big deal, but
better to fix.
A cleaner and more precise fix is to include the objtool command in
*.cmd files so any command change is naturally detected by if_change.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>Reviewed-by: Nick Desaulniers <redacted>
quoted hunk ↗ jump to hunk
--- scripts/Makefile.build | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-)diff --git a/scripts/Makefile.build b/scripts/Makefile.build index e78096cd396b..021ae0146913 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build@@ -155,7 +155,7 @@ $(obj)/%.ll: $(src)/%.c FORCE # (See cmd_cc_o_c + relevant part of rule_cc_o_c) quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ - cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< + cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool) ifdef CONFIG_MODVERSIONS # When module versioning is enabled the following steps are executed:@@ -243,7 +243,7 @@ ifndef CONFIG_LTO_CLANG # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file cmd_objtool = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ - $(objtool) $(objtool_args) $@) + ; $(objtool) $(objtool_args) $@) objtool_obj = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ $(objtool))@@ -251,10 +251,8 @@ objtool_obj = $(if $(patsubst y%,, \ endif # CONFIG_LTO_CLANG endif # CONFIG_STACK_VALIDATION -# Rebuild all objects when objtool changes, or is enabled/disabled. -objtool_dep = $(objtool_obj) \ - $(wildcard include/config/ORC_UNWINDER \ - include/config/STACK_VALIDATION) +# Rebuild all objects when objtool changes +objtool_dep = $(objtool_obj) ifdef CONFIG_TRIM_UNUSED_KSYMS cmd_gen_ksymdeps = \@@ -269,7 +267,6 @@ define rule_cc_o_c $(call cmd,gen_ksymdeps) $(call cmd,checksrc) $(call cmd,checkdoc) - $(call cmd,objtool) $(call cmd,modversions_c) $(call cmd,record_mcount) endef@@ -277,7 +274,6 @@ endef define rule_as_o_S $(call cmd_and_fixdep,as_o_S) $(call cmd,gen_ksymdeps) - $(call cmd,objtool) $(call cmd,modversions_S) endef@@ -365,7 +361,7 @@ $(obj)/%.s: $(src)/%.S FORCE $(call if_changed_dep,cpp_s_S) quiet_cmd_as_o_S = AS $(quiet_modtag) $@ - cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< + cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool) ifdef CONFIG_ASM_MODVERSIONS --2.30.2
-- Thanks, ~Nick Desaulniers