LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: Masahiro Yamada <masahiroy@kernel.org>,
	Michal Marek <michal.lkml@markovi.net>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org
Subject: [PATCH v2 06/13] kbuild: reuse $(cmd_objtool) for cmd_cc_lto_link_modules
Date: Tue, 31 Aug 2021 16:39:57 +0900	[thread overview]
Message-ID: <20210831074004.3195284-7-masahiroy@kernel.org> (raw)
In-Reply-To: <20210831074004.3195284-1-masahiroy@kernel.org>

For CONFIG_LTO_CLANG=y, the objtool processing is not possible at the
compilation, hence postponed by the link time.

Reuse $(cmd_objtool) for CONFIG_LTO_CLANG=y by defining objtool-enabled
properly.

For CONFIG_LTO_CLANG=y:

  objtool-enabled is off for %.o compilation
  objtool-enabled is on  for %.lto link

For CONFIG_LTO_CLANG=n:

  objtool-enabled is on for %.o compilation
      (but, it depends on OBJECT_FILE_NON_STANDARD)

Set part-of-module := y for %.lto.o to avoid repeating --module.

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

 scripts/Makefile.build | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 21b55f37a23f..afc906cd7256 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -236,20 +236,26 @@ objtool_args =								\
 	$(if $(CONFIG_X86_SMAP), --uaccess)				\
 	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)
 
-ifndef CONFIG_LTO_CLANG
+cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
+cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
+
+endif # CONFIG_STACK_VALIDATION
+
+ifdef CONFIG_LTO_CLANG
+
+# Skip objtool for LLVM bitcode
+$(obj)/%o: objtool-enabled :=
+
+else
 
 # '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
 
-objtool-enabled = $(if $(filter-out y%, \
+$(obj)/%o: objtool-enabled = $(if $(filter-out y%, \
 	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
 
-cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
-cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
-
-endif # CONFIG_LTO_CLANG
-endif # CONFIG_STACK_VALIDATION
+endif
 
 ifdef CONFIG_TRIM_UNUSED_KSYMS
 cmd_gen_ksymdeps = \
@@ -289,13 +295,13 @@ cmd_cc_lto_link_modules =						\
 	$(LD) $(ld_flags) -r -o $@					\
 		$(shell [ -s $(@:.lto.o=.o.symversions) ] &&		\
 			echo -T $(@:.lto.o=.o.symversions))		\
-		--whole-archive $(filter-out FORCE,$^)
+		--whole-archive $(filter-out FORCE,$^)			\
+		$(cmd_objtool)
 
-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 += ; $(objtool) $(objtool_args) --module $@
-endif
+$(obj)/%.lto.o: objtool-enabled = y
+$(obj)/%.lto.o: part-of-module := y
 
 $(obj)/%.lto.o: $(obj)/%.o FORCE
 	$(call if_changed,cc_lto_link_modules)
-- 
2.30.2


  parent reply	other threads:[~2021-08-31  7:41 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31  7:39 [PATCH v2 00/13] kbuild: second round of Clang LTO refactoring Masahiro Yamada
2021-08-31  7:39 ` [PATCH v2 01/13] kbuild: move objtool_args back to scripts/Makefile.build Masahiro Yamada
2021-09-04 18:18   ` Josh Poimboeuf
2021-08-31  7:39 ` [PATCH v2 02/13] kbuild: rename __objtool_obj to objtool Masahiro Yamada
2021-08-31 17:16   ` Nick Desaulniers
2021-08-31 17:29   ` Kees Cook
2021-09-04 18:19   ` Josh Poimboeuf
2021-08-31  7:39 ` [PATCH v2 03/13] kbuild: store the objtool command in *.cmd files Masahiro Yamada
2021-08-31 17:23   ` Nick Desaulniers
2021-08-31 17:30   ` Kees Cook
2021-09-04 18:04   ` Josh Poimboeuf
2021-09-04 18:45     ` Josh Poimboeuf
2021-09-08 16:12       ` Masahiro Yamada
2021-08-31  7:39 ` [PATCH v2 04/13] kbuild: factor out OBJECT_FILES_NON_STANDARD check into a macro Masahiro Yamada
2021-08-31 17:25   ` Nick Desaulniers
2021-08-31 17:31   ` Kees Cook
2021-09-04 18:59   ` Josh Poimboeuf
2021-08-31  7:39 ` [PATCH v2 05/13] kbuild: detect objtool update without using .SECONDEXPANSION Masahiro Yamada
2021-08-31 17:32   ` Kees Cook
2021-09-03  0:43     ` Masahiro Yamada
2021-08-31 17:33   ` Nick Desaulniers
2021-09-02 23:42     ` Masahiro Yamada
2021-09-04 19:04   ` Josh Poimboeuf
2021-08-31  7:39 ` Masahiro Yamada [this message]
2021-08-31 17:35   ` [PATCH v2 06/13] kbuild: reuse $(cmd_objtool) for cmd_cc_lto_link_modules Kees Cook
2021-09-03  0:39     ` Masahiro Yamada
2021-09-03  1:49       ` Kees Cook
2021-09-04 19:11   ` Josh Poimboeuf
2021-08-31  7:39 ` [PATCH v2 07/13] kbuild: do not create built-in.a.symversions or lib.a.symversions Masahiro Yamada
2021-08-31 17:36   ` Kees Cook
2021-08-31  7:39 ` [PATCH v2 08/13] kbuild: build modules in the same way with/without Clang LTO Masahiro Yamada
2021-08-31 17:39   ` Kees Cook
2021-08-31 17:46   ` Nick Desaulniers
2021-08-31  7:40 ` [PATCH v2 09/13] kbuild: add cmd_and_savecmd macro Masahiro Yamada
2021-08-31 17:39   ` Kees Cook
2021-08-31  7:40 ` [PATCH v2 10/13] kbuild: rebuild modules when objtool is updated for CONFIG_LTO_CLANG Masahiro Yamada
2021-08-31 17:40   ` Kees Cook
2021-09-04 19:13   ` Josh Poimboeuf
2021-08-31  7:40 ` [PATCH v2 11/13] kbuild: always postpone CRC links for module versioning Masahiro Yamada
2021-08-31  7:40 ` [PATCH v2 12/13] kbuild: merge cmd_modversions_c and cmd_modversions_S Masahiro Yamada
2021-08-31  7:40 ` [PATCH v2 13/13] kbuild: merge cmd_ar_builtin and cmd_ar_module Masahiro Yamada

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210831074004.3195284-7-masahiroy@kernel.org \
    --to=masahiroy@kernel.org \
    --cc=clang-built-linux@googlegroups.com \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=michal.lkml@markovi.net \
    --cc=nathan@kernel.org \
    --cc=ndesaulniers@google.com \
    --subject='Re: [PATCH v2 06/13] kbuild: reuse $(cmd_objtool) for cmd_cc_lto_link_modules' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).