From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C4A1C433F5 for ; Sun, 29 May 2022 14:47:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230468AbiE2OrL (ORCPT ); Sun, 29 May 2022 10:47:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229934AbiE2OrI (ORCPT ); Sun, 29 May 2022 10:47:08 -0400 Received: from mail-il1-x130.google.com (mail-il1-x130.google.com [IPv6:2607:f8b0:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3BD726432; Sun, 29 May 2022 07:47:07 -0700 (PDT) Received: by mail-il1-x130.google.com with SMTP id 3so6113367ily.2; Sun, 29 May 2022 07:47:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=hhqrhJhsaClgvvck9Sdle86jJdiS7n38zO76P0oYBJk=; b=G5zCZeQjgij/x9j+WIEMt67AuFY8XBSL6bkzbHpXJcF7jcxgjeGc5S5nmoXWEBcgeQ x7UVDeXO0X1nMJegFqr/sLhx1ImhEERzOTXszsleVdmENixOzSm9BoN9ocCgr/3LcQ8j xFr5jAGPCKjZJCKinWKTWf79oa3ZtQLwJXy8NsZoz/FvKn6HsSebjqjmAI4moT7OafZy zIZ0yabpPPGSEokaMEydo0Y1fvAByU3cmcqyD2FPJ8sxBYMvR/D4cXLztnLrhJWqbvak uslyq7FC4ykHEjiVZ3GF8TnmkEpTD4zVE9nl0LGaRYKBBrS3EKheTm93rK4awIzPTT8r nFbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc; bh=hhqrhJhsaClgvvck9Sdle86jJdiS7n38zO76P0oYBJk=; b=U3l6LlWMkkbXwsXXJv7wVGeqCk3BZMXKn34pdu6S2vpOdbGlalC10phf0ZQ7KzpPMu dUNZT9ozTQOIC3wra4hKDREsl6wUUdExSx3+ncKVDdrfanYZ+Vam4F3OhHRAXpM+duQu IhxUbBzZyFurFySWkw5X32RffyxWJ8Gbff608GXxWBHgkCcZk8UyEdzzOJacx7zx46fJ TiGOeMspSq6XNXNQO1O7YlG0k2zKzQv3+fhXE65wPLXXWM7yx/tmaAY5pMnZ9OiqUSAq udghgu55E0TqvfFnPIz8W3To3rI4SM6EXAc88c2H1nVACtcSG92PQXcO+rpOzI7Jnpkz kI4Q== X-Gm-Message-State: AOAM530YjSFw0D/aCXjlbycqE3ca6T1r8RUeDlrGEdZoARndjMto/yWB j83wNMtoJwe2Ljm6A/wHqcv4RQjjx+ZJowgYb9U= X-Google-Smtp-Source: ABdhPJxruu+kkXLX0MVi2Fmhp97UmKzyHBwfBvsCZ7Xm5BaC7ya2im7SAGOqXf+AQZfsQzi0FgTUxrcT9Qhs+y1VqVA= X-Received: by 2002:a05:6e02:1aa8:b0:2d1:7099:67ba with SMTP id l8-20020a056e021aa800b002d1709967bamr24297718ilv.1.1653835626507; Sun, 29 May 2022 07:47:06 -0700 (PDT) MIME-Version: 1.0 References: <20220528154704.2576290-1-masahiroy@kernel.org> <20220528154704.2576290-4-masahiroy@kernel.org> In-Reply-To: <20220528154704.2576290-4-masahiroy@kernel.org> Reply-To: sedat.dilek@gmail.com From: Sedat Dilek Date: Sun, 29 May 2022 16:46:30 +0200 Message-ID: Subject: Re: [PATCH 4/4] kbuild: factor out the common objtool arguments To: Masahiro Yamada Cc: linux-kbuild@vger.kernel.org, Nick Desaulniers , linux-kernel@vger.kernel.org, Josh Poimboeuf , Michal Marek Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 28, 2022 at 9:45 PM Masahiro Yamada wrote: > > scripts/Makefile.build and scripts/link-vmlinux.sh have similar setups > for the objtool arguments. > > It is difficult to factor out them because the vmlinux build rule is > written in a shell script. It is somewhat tedious to touch the two > files every time a new objtool option is supported. > > To reduce the code duplication, implement everything about objtool in > Makefile. > > Move the objtool for vmlinux.o into scripts/Makefile.vmlinux_o. > > Move the common macros to Makefile.lib so they are shared by > Makefile.build and Makefile.vmlinux_o. > > Signed-off-by: Masahiro Yamada With some comments (see below). Tested-by: Sedat Dilek # LLVM-14 (x86-64) -Sedat- > --- > > scripts/Makefile.build | 26 -------------- > scripts/Makefile.lib | 26 ++++++++++++++ > scripts/Makefile.vmlinux_o | 26 ++++++++++++++ > scripts/link-vmlinux.sh | 71 -------------------------------------- > 4 files changed, 52 insertions(+), 97 deletions(-) > > diff --git a/scripts/Makefile.build b/scripts/Makefile.build > index 4cb7145071b9..1f01ac65c0cd 100644 > --- a/scripts/Makefile.build > +++ b/scripts/Makefile.build > @@ -210,38 +210,12 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), > $(sub_cmd_record_mcount)) > endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT > > -ifdef CONFIG_OBJTOOL > - > -objtool := $(objtree)/tools/objtool/objtool > - > -objtool_args = \ > - $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \ > - $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \ > - $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \ > - $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ > - $(if $(CONFIG_UNWINDER_ORC), --orc) \ > - $(if $(CONFIG_RETPOLINE), --retpoline) \ > - $(if $(CONFIG_SLS), --sls) \ > - $(if $(CONFIG_STACK_VALIDATION), --stackval) \ > - $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \ > - --uaccess \ > - $(if $(delay-objtool), --link) \ > - $(if $(part-of-module), --module) \ > - $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) > - > -cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@) > -cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) > - > -endif # CONFIG_OBJTOOL > - > # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory > # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file > # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file > ^^ What is with this block? If this belongs together with objtool - shall this be moved, too? > is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y) > > -delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) > - > $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y)) > > ifdef CONFIG_TRIM_UNUSED_KSYMS > diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib > index f75138385449..f691fb231ce5 100644 > --- a/scripts/Makefile.lib > +++ b/scripts/Makefile.lib > @@ -225,6 +225,32 @@ dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ > $(addprefix -I,$(DTC_INCLUDE)) \ > -undef -D__DTS__ > > +ifdef CONFIG_OBJTOOL > + > +objtool := $(objtree)/tools/objtool/objtool > + > +objtool_args = \ > + $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \ > + $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \ > + $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \ > + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ > + $(if $(CONFIG_UNWINDER_ORC), --orc) \ > + $(if $(CONFIG_RETPOLINE), --retpoline) \ > + $(if $(CONFIG_SLS), --sls) \ > + $(if $(CONFIG_STACK_VALIDATION), --stackval) \ > + $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \ > + --uaccess \ > + $(if $(delay-objtool), --link) \ > + $(if $(part-of-module), --module) \ > + $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) > + > +delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) > + > +cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@) > +cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) > + > +endif # CONFIG_OBJTOOL > + > # Useful for describing the dependency of composite objects > # Usage: > # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) > diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o > index a9b375ca86d5..3c97a1564947 100644 > --- a/scripts/Makefile.vmlinux_o > +++ b/scripts/Makefile.vmlinux_o > @@ -6,6 +6,9 @@ __default: vmlinux.o > include include/config/auto.conf > include $(srctree)/scripts/Kbuild.include > > +# for objtool > +include $(srctree)/scripts/Makefile.lib > + > # Generate a linker script to ensure correct ordering of initcalls for Clang LTO > # --------------------------------------------------------------------------- > > @@ -24,6 +27,27 @@ ifdef CONFIG_LTO_CLANG > initcalls-lds := .tmp_initcalls.lds > endif > > +# objtool for vmlinux.o > +# --------------------------------------------------------------------------- > +# > +# For LTO and IBT, objtool doesn't run on individual translation units. > +# Run everything on vmlinux instead. > + > +objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) > + > +# Reuse objtool_args defined in scripts/Makefile.lib if LTO or IBT is enabled. > +# > +# Add some more flags as needed. > +# --no-unreachable and --link might be added twice, but it is fine. > +# > +# Expand objtool_args to a simple variable to avoid circular reference. > + > +objtool_args := \ > + $(if $(delay-objtool),$(objtool_args)) \ > + $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr) \ > + $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \ > + --link > + > # Link of vmlinux.o used for section mismatch analysis > # --------------------------------------------------------------------------- > > @@ -33,9 +57,11 @@ quiet_cmd_ld_vmlinux.o = LD $@ > $(addprefix -T , $(initcalls-lds)) \ > --whole-archive $(KBUILD_VMLINUX_OBJS) --no-whole-archive \ > --start-group $(KBUILD_VMLINUX_LIBS) --end-group \ > + $(cmd_objtool) > > define rule_ld_vmlinux.o > $(call cmd_and_savecmd,ld_vmlinux.o) > + $(call cmd,gen_objtooldep) > endef > > vmlinux.o: $(initcalls-lds) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE > diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh > index 90680b6bd710..1ac4e180fa3f 100755 > --- a/scripts/link-vmlinux.sh > +++ b/scripts/link-vmlinux.sh > @@ -45,76 +45,6 @@ info() > printf " %-7s %s\n" "${1}" "${2}" > } > > -objtool_link() > -{ > - local objtoolcmd; > - local objtoolopt; > - > - if ! is_enabled CONFIG_OBJTOOL; then > - return; > - fi > - > - if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then > - > - # For LTO and IBT, objtool doesn't run on individual > - # translation units. Run everything on vmlinux instead. > - > - if is_enabled CONFIG_HAVE_JUMP_LABEL_HACK; then > - objtoolopt="${objtoolopt} --hacks=jump_label" > - fi > - > - if is_enabled CONFIG_HAVE_NOINSTR_HACK; then > - objtoolopt="${objtoolopt} --hacks=noinstr" > - fi > - > - if is_enabled CONFIG_X86_KERNEL_IBT; then > - objtoolopt="${objtoolopt} --ibt" > - fi > - > - if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then > - objtoolopt="${objtoolopt} --mcount" > - fi > - > - if is_enabled CONFIG_UNWINDER_ORC; then > - objtoolopt="${objtoolopt} --orc" > - fi > - > - if is_enabled CONFIG_RETPOLINE; then > - objtoolopt="${objtoolopt} --retpoline" > - fi > - > - if is_enabled CONFIG_SLS; then > - objtoolopt="${objtoolopt} --sls" > - fi > - > - if is_enabled CONFIG_STACK_VALIDATION; then > - objtoolopt="${objtoolopt} --stackval" > - fi > - > - if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then > - objtoolopt="${objtoolopt} --static-call" > - fi > - > - objtoolopt="${objtoolopt} --uaccess" > - fi > - > - if is_enabled CONFIG_NOINSTR_VALIDATION; then > - objtoolopt="${objtoolopt} --noinstr" > - fi > - > - if [ -n "${objtoolopt}" ]; then > - > - if is_enabled CONFIG_GCOV_KERNEL; then > - objtoolopt="${objtoolopt} --no-unreachable" > - fi > - > - objtoolopt="${objtoolopt} --link" > - > - info OBJTOOL ${1} > - tools/objtool/objtool ${objtoolopt} ${1} > - fi > -} > - > # Link of vmlinux > # ${1} - output file > # ${2}, ${3}, ... - optional extra .o files > @@ -298,7 +228,6 @@ ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 > > #link vmlinux.o ^^ While you are at it, change the comment to "# Link of vmlinux.o". > ${MAKE} -f "${srctree}/scripts/Makefile.vmlinux_o" > -objtool_link vmlinux.o > > # Generate the list of objects in vmlinux > for f in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do > -- > 2.32.0 >