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From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: Masahiro Yamada <masahiroy@kernel.org>,
	Michal Marek <michal.lkml@markovi.net>,
	Nick Desaulniers <ndesaulniers@google.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 4/5] kbuild: merge objtool_args into objtool in scripts/Makefile.build
Date: Sat, 28 Aug 2021 18:51:02 +0900	[thread overview]
Message-ID: <20210828095103.2617393-4-masahiroy@kernel.org> (raw)
In-Reply-To: <20210828095103.2617393-1-masahiroy@kernel.org>

Commit b1a1a1a09b46 ("kbuild: lto: postpone objtool") moved objtool_args
to Makefile.lib, so the arguments can be used in Makefile.modfinal as
well as Makefile.build.

With commit 2b1d7fc05467 ("kbuild: Fix TRIM_UNUSED_KSYMS with
LTO_CLANG"), module LTO linking came back to scripts/Makefile.build
again.

So, there is no more reason to keep objtool_args in a separate file.

Move it to scripts/Makefile.build and merge into the 'objtool' variable.

You might wonder why cmd_cc_lto_link_modules adds --module again. Add
a small comment to explain it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/Makefile.build | 19 ++++++++++++++-----
 scripts/Makefile.lib   | 11 -----------
 2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 8aa6eaa4bf21..cc0c494a48d3 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -224,9 +224,17 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),
 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 
 ifdef CONFIG_STACK_VALIDATION
-ifndef CONFIG_LTO_CLANG
 
-objtool := $(objtree)/tools/objtool/objtool
+objtool = $(objtree)/tools/objtool/objtool				\
+	$(if $(CONFIG_UNWINDER_ORC),orc generate,check)			\
+	$(if $(part-of-module), --module)				\
+	$(if $(CONFIG_FRAME_POINTER),, --no-fp)				\
+	$(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
+	$(if $(CONFIG_RETPOLINE), --retpoline)				\
+	$(if $(CONFIG_X86_SMAP), --uaccess)				\
+	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)
+
+ifndef CONFIG_LTO_CLANG
 
 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
@@ -236,7 +244,7 @@ objtool := $(objtree)/tools/objtool/objtool
 # rebuilding objects.
 cmd_objtool = $(if $(patsubst y%,, \
 	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
-	; : $(objtool-md5sum) ; $(objtool) $(objtool_args) $@)
+	; : $(objtool-md5sum) ; $(objtool) $@)
 
 endif # CONFIG_LTO_CLANG
 endif # CONFIG_STACK_VALIDATION
@@ -282,8 +290,9 @@ cmd_cc_lto_link_modules =						\
 ifdef CONFIG_STACK_VALIDATION
 # objtool was skipped for LLVM bitcode, run it now that we have compiled
 # modules into native code
-cmd_cc_lto_link_modules += ;						\
-	$(objtree)/tools/objtool/objtool $(objtool_args) --module $@
+#
+# Repeat --module because $(part-of-module) does not work here.
+cmd_cc_lto_link_modules += ; $(objtool) --module $@
 endif
 
 $(obj)/%.lto.o: $(obj)/%.o FORCE
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index cd011f3f6f78..34c4c11c4bc1 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -232,17 +232,6 @@ ifeq ($(CONFIG_LTO_CLANG),y)
 mod-prelink-ext := .lto
 endif
 
-# Objtool arguments are also needed for modfinal with LTO, so we define
-# then here to avoid duplication.
-objtool_args =								\
-	$(if $(CONFIG_UNWINDER_ORC),orc generate,check)			\
-	$(if $(part-of-module), --module)				\
-	$(if $(CONFIG_FRAME_POINTER),, --no-fp)				\
-	$(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
-	$(if $(CONFIG_RETPOLINE), --retpoline)				\
-	$(if $(CONFIG_X86_SMAP), --uaccess)				\
-	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)
-
 # Useful for describing the dependency of composite objects
 # Usage:
 #   $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
-- 
2.30.2


  parent reply	other threads:[~2021-08-28  9:51 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-28  9:50 [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada
2021-08-28  9:51 ` [PATCH 2/5] kbuild: detect objtool changes correctly without .SECONDEXPANSION Masahiro Yamada
2021-08-31  1:43   ` Masahiro Yamada
2021-08-28  9:51 ` [PATCH 3/5] kbuild: clean up objtool_args slightly Masahiro Yamada
2021-08-31  1:41   ` Masahiro Yamada
2021-08-28  9:51 ` Masahiro Yamada [this message]
2021-08-28  9:51 ` [PATCH 5/5] kbuild: rebuild *.lto.o when objtool is changed Masahiro Yamada
2021-08-31  1:41 ` [PATCH 1/5] modpost: get the *.mod file path more simply Masahiro Yamada

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