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From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Masahiro Yamada <masahiroy@kernel.org>,
	Michal Marek <michal.lkml@markovi.net>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	llvm@lists.linux.dev
Subject: [PATCH v2 09/10] kbuild: refactor cmd_modversions_c
Date: Tue,  5 Apr 2022 23:02:28 +0900	[thread overview]
Message-ID: <20220405140229.2895394-10-masahiroy@kernel.org> (raw)
In-Reply-To: <20220405140229.2895394-1-masahiroy@kernel.org>

cmd_modversions_c implements two parts; run genksyms to calculate CRCs
of exported symbols, run $(LD) to update the object with the CRCs. The
latter is not executed for CONFIG_LTO_CLANG=y since the object is not
ELF but LLVM bit code at this point.

The first part can be unified because we can always use $(NM) instead
of "$(OBJDUMP) -h" to dump the symbols.

Split the code into the two macros, cmd_gen_symversions_c and
cmd_modversions.

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

Changes in v2:
 - new

 scripts/Makefile.build | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index d934bdf84de4..ba2be555f942 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -169,29 +169,25 @@ ifdef CONFIG_MODVERSIONS
 #   the actual value of the checksum generated by genksyms
 # o remove .tmp_<file>.o to <file>.o
 
-ifdef CONFIG_LTO_CLANG
 # Generate .o.symversions files for each .o with exported symbols, and link these
 # to the kernel and/or modules at the end.
-cmd_modversions_c =								\
+gen_symversions =								\
 	if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then			\
-		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
+		$(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
 		    > $@.symversions;						\
 	else									\
 		rm -f $@.symversions;						\
-	fi;
-else
-cmd_modversions_c =								\
-	if $(OBJDUMP) -h $@ | grep -q __ksymtab; then				\
-		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
-		    > $(@D)/.tmp_$(@F:.o=.ver);					\
-										\
+	fi
+
+cmd_gen_symversions_c =	$(call gen_symversions,c)
+
+cmd_modversions =								\
+	if [ -r $@.symversions ]; then						\
 		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
-			-T $(@D)/.tmp_$(@F:.o=.ver);				\
+			-T $@.symversions;					\
 		mv -f $(@D)/.tmp_$(@F) $@;					\
-		rm -f $(@D)/.tmp_$(@F:.o=.ver);					\
 	fi
 endif
-endif
 
 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
@@ -269,7 +265,8 @@ define rule_cc_o_c
 	$(call cmd,checksrc)
 	$(call cmd,checkdoc)
 	$(call cmd,gen_objtooldep)
-	$(call cmd,modversions_c)
+	$(call cmd,gen_symversions_c)
+	$(if $(CONFIG_LTO_CLANG),,$(call cmd,modversions))
 	$(call cmd,record_mcount)
 endef
 
-- 
2.32.0


  parent reply	other threads:[~2022-04-05 23:25 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-05 14:02 [PATCH v2 00/10] kbuild: misc cleanups Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 01/10] kbuild: factor out genksyms command from cmd_gensymtypes_{c,S} Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 02/10] kbuild: do not remove empty *.symtypes explicitly Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 03/10] modpost: remove useless export_from_sec() Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 04/10] modpost: move export_from_secname() call to more relevant place Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 05/10] modpost: remove redundant initializes for static variables Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 06/10] modpost: remove annoying namespace_from_kstrtabns() Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 07/10] kbuild: get rid of duplication in the first line of *.mod files Masahiro Yamada
2022-04-05 14:02 ` [PATCH v2 08/10] kbuild: split the second line of *.mod into *.usyms Masahiro Yamada
2022-04-05 14:02 ` Masahiro Yamada [this message]
2022-04-05 14:02 ` [PATCH v2 10/10] kbuild: refactor cmd_modversions_S Masahiro Yamada
  -- strict thread matches above, loose matches on Subject: below --
2022-04-05 11:33 [PATCH v2 00/10] kbuild: misc cleanups Masahiro Yamada
2022-04-05 11:33 ` [PATCH v2 09/10] kbuild: refactor cmd_modversions_c Masahiro Yamada
2022-04-05 16:42   ` Nick Desaulniers

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