From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: Sami Tolvanen <samitolvanen@google.com>,
linux-kernel@vger.kernel.org,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH 03/13] kbuild: detect objtool changes correctly and remove .SECONDEXPANSION
Date: Thu, 19 Aug 2021 09:57:34 +0900 [thread overview]
Message-ID: <20210819005744.644908-4-masahiroy@kernel.org> (raw)
In-Reply-To: <20210819005744.644908-1-masahiroy@kernel.org>
This reverts commit 8852c5524029 ("kbuild: Fix objtool dependency for
'OBJECT_FILES_NON_STANDARD_<obj> := n'"), and fix the dependency in a
cleaner way.
Using .SECONDEXPANSION is expensive since Makefile.build is parsed
twice every time, and the escaping dollars makes the code unreadable.
Adding include/config/* as dependency is not maintainable either because
objtool_args is dependent on more CONFIG options.
A better 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>
---
scripts/Makefile.build | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 31154e44c251..3e4cd1439cd4 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:
@@ -223,6 +223,8 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
ifdef CONFIG_STACK_VALIDATION
+objtool := $(objtree)/tools/objtool/objtool
+
# Objtool arguments are also needed for modfinal with LTO, so we define
# then here to avoid duplication.
objtool_args = \
@@ -237,26 +239,19 @@ objtool_args = \
ifndef CONFIG_LTO_CLANG
-__objtool_obj := $(objtree)/tools/objtool/objtool
-
# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
# '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
cmd_objtool = $(if $(patsubst y%,, \
$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
- $(__objtool_obj) $(objtool_args) $@)
-objtool_obj = $(if $(patsubst y%,, \
- $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
- $(__objtool_obj))
+ ; $(objtool) $(objtool_args) $@)
+
+# Rebuild all objects when objtool is updated
+objtool_dep = $(objtool)
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)
-
ifdef CONFIG_TRIM_UNUSED_KSYMS
cmd_gen_ksymdeps = \
$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
@@ -270,7 +265,6 @@ 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
@@ -278,13 +272,11 @@ endef
define rule_as_o_S
$(call cmd_and_fixdep,as_o_S)
$(call cmd,gen_ksymdeps)
- $(call cmd,objtool)
$(call cmd,modversions_S)
endef
# Built-in and composite module parts
-.SECONDEXPANSION:
-$(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
+$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
$(call if_changed_rule,cc_o_c)
$(call cmd,force_checksrc)
@@ -367,7 +359,7 @@ $(obj)/%.s: $(src)/%.S FORCE
$(call if_changed_dep,cpp_s_S)
quiet_cmd_as_o_S = AS $(quiet_modtag) $@
- cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
+ cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
ifdef CONFIG_ASM_MODVERSIONS
@@ -386,7 +378,7 @@ cmd_modversions_S = \
fi
endif
-$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
+$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
$(call if_changed_rule,as_o_S)
targets += $(filter-out $(subdir-builtin), $(real-obj-y))
--
2.30.2
next prev parent reply other threads:[~2021-08-19 0:58 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-19 0:57 [PATCH 00/13] kbuild: refactoring after Clang LTO Masahiro Yamada
2021-08-19 0:57 ` [PATCH 01/13] kbuild: move objtool_args back to scripts/Makefile.build Masahiro Yamada
2021-08-19 2:45 ` Kees Cook
2021-08-19 0:57 ` [PATCH 02/13] gen_compile_commands: extract compiler command from a series of commands Masahiro Yamada
2021-08-19 6:48 ` Kees Cook
2021-08-19 0:57 ` Masahiro Yamada [this message]
2021-08-19 2:55 ` [PATCH 03/13] kbuild: detect objtool changes correctly and remove .SECONDEXPANSION Kees Cook
2021-08-19 3:18 ` Masahiro Yamada
2021-08-19 0:57 ` [PATCH 04/13] kbuild: remove unused quiet_cmd_update_lto_symversions Masahiro Yamada
2021-08-19 6:19 ` Kees Cook
2021-08-19 0:57 ` [PATCH 05/13] kbuild: remove stale *.symversions Masahiro Yamada
2021-08-19 6:29 ` Kees Cook
2021-08-19 0:57 ` [PATCH 06/13] kbuild: merge vmlinux_link() between the ordinary link and Clang LTO Masahiro Yamada
2021-08-19 2:42 ` Kees Cook
2021-08-19 0:57 ` [PATCH 07/13] kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh Masahiro Yamada
2021-08-19 6:32 ` Kees Cook
2021-08-19 0:57 ` [PATCH 08/13] kbuild: merge vmlinux_link() between ARCH=um and other architectures Masahiro Yamada
2021-08-19 2:43 ` Kees Cook
2021-08-19 0:57 ` [PATCH 09/13] kbuild: do not create built-in.a.symversions or lib.a.symversions Masahiro Yamada
2021-08-19 6:41 ` Kees Cook
2021-08-28 11:57 ` Masahiro Yamada
2021-08-19 0:57 ` [PATCH 10/13] kbuild: build modules in the same way with/without Clang LTO Masahiro Yamada
2021-08-19 6:59 ` Kees Cook
2021-08-19 8:11 ` Masahiro Yamada
2021-08-19 0:57 ` [PATCH 11/13] kbuild: always postpone CRC links for module versioning Masahiro Yamada
2021-08-19 6:43 ` Kees Cook
2021-08-19 0:57 ` [PATCH 12/13] kbuild: merge cmd_modversions_c and cmd_modversions_S Masahiro Yamada
2021-08-19 3:06 ` Kees Cook
2021-08-19 0:57 ` [PATCH 13/13] kbuild: merge cmd_ar_builtin and cmd_ar_module Masahiro Yamada
2021-08-19 3:01 ` Kees Cook
2021-08-25 4:57 ` [PATCH 00/13] kbuild: refactoring after Clang LTO Masahiro Yamada
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