From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7AEDA387378; Fri, 28 Aug 2026 04:52:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787892721; cv=none; b=SQttW9+XO3U6hSf42BTHMKGc2OepuXxfwVS4UAVkG8rgyowmWh3EwE/65x37OZkcanvSjWc/VpJZwEt8QLSZwCEQEb5zRsmnqOV5txbz063JvafjMqQ3BPDTw4KAfgOLt7vZVSV5lEdDIivIjXfPw8/CFBC/fnvUpWfAppzjbS8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787892721; c=relaxed/simple; bh=O17sPWEBzUDpZ3eFIdHZvdyeXtMGdpbhRQ3FrAb7PUA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bn/MFByyJq+UPoLGnh0H1Feke7WHYIzAd56UeBGdJf+JLlewiwdNZZxvaKGBWgxrICR8ImGiK1BPcnhRYfJgaTQi6jUBQhTP0rt+P17kyseYcdAtFfx7vp+GC+UyGjuDLr8HLW4Xyaj3BNVDDGRelFrlTJ6qizgM5+2hmse7+vI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FBd+T0co; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FBd+T0co" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E6EF1F00A3A; Fri, 28 Aug 2026 04:51:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787892720; bh=cCzCbUnHZwUow4j2tnWYFPvTYWDRft0EQI0YfGcfzIA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FBd+T0coABTJMG5I1mGk0ZyRMFIUcSbIj6FtxF9Y/VbRE5MqsRuVK1Kkes/1lHm4X tDN82upp28YUeyfQdqjR56FHZj5r7eibSKXSdv4AfMrl8FmOkILAniT94ojZEQGvBR VXSLwmIh8WfUxj1a50wJE55try0JHj9sgFQa/sa55Clrhv25Ug9S8PZIYr2l1sP9Td wI34Nj2fXfyvSjhMFL/QGNVyUDfNJM2fxsD9cK3fmy4qMVp1Ujk3ViNh6BC+m2L+In ruznyjRPH7YFeK3fv25A/ENWx9JfiEspvySMbut3bfU1RCu5LmP6ZJHXxQhDFG0SKm qhtGZkEmK5grA== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Gary Guo , rust-for-linux@vger.kernel.org, Ard Biesheuvel , Miguel Ojeda , Nathan Chancellor , Nicolas Schier , linux-kbuild@vger.kernel.org, Huacai Chen Subject: [PATCH 02/27] kbuild: Add CONFIG_OBJTOOL_DEFERRED Date: Thu, 27 Aug 2026 21:51:31 -0700 Message-ID: <6b9243d1a7ecfa1bf4fc9163724cbc6b3928be30.1787890035.git.jpoimboe@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit For LTO, IBT, and KLP builds, the running of objtool is deferred to vmlinux.o rather than individual translation units. In preparation for deferring it in more cases, add a new config option. No functional change. Signed-off-by: Josh Poimboeuf --- arch/x86/boot/startup/Makefile | 2 +- lib/Kconfig.debug | 7 +++++++ scripts/Makefile.build | 4 ++-- scripts/Makefile.lib | 4 +--- scripts/Makefile.vmlinux_o | 13 +++++++------ scripts/link-vmlinux.sh | 3 +-- 6 files changed, 19 insertions(+), 14 deletions(-) diff --git a/arch/x86/boot/startup/Makefile b/arch/x86/boot/startup/Makefile index 5e499cfb29b5c..ab6e9970d4f4e 100644 --- a/arch/x86/boot/startup/Makefile +++ b/arch/x86/boot/startup/Makefile @@ -36,7 +36,7 @@ $(patsubst %.o,$(obj)/%.o,$(lib-y)): OBJECT_FILES_NON_STANDARD := y # relocations, even if other objtool actions are being deferred. # $(pi-objs): objtool-enabled = 1 -$(pi-objs): objtool-args = $(if $(delay-objtool),--dry-run,$(objtool-args-y)) --noabs +$(pi-objs): objtool-args = $(if $(CONFIG_OBJTOOL_DEFERRED),--dry-run,$(objtool-args-y)) --noabs # # Confine the startup code by prefixing all symbols with __pi_ (for position diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1244dcac2294a..9ca9b2519d604 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -588,6 +588,13 @@ config NOINSTR_VALIDATION select OBJTOOL default y +# For when objtool defers its work to the linked image (vmlinux.o or module.o) +# rather than running on individual translation units. +config OBJTOOL_DEFERRED + def_bool y + depends on OBJTOOL + depends on LTO_CLANG || X86_KERNEL_IBT || KLP_BUILD + config VMLINUX_MAP bool "Generate vmlinux.map file when linking" depends on EXPERT diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 9117457432463..84ef12f784330 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -277,7 +277,7 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),$(is-kernel-object)) ifdef CONFIG_OBJTOOL -$(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y)) +$(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(CONFIG_OBJTOOL_DEFERRED),$(is-single-obj-m),y)) endif ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) @@ -502,7 +502,7 @@ define rule_ld_multi_m $(call cmd,gen_objtooldep) endef -$(multi-obj-m): private objtool-enabled := $(delay-objtool) +$(multi-obj-m): private objtool-enabled := $(CONFIG_OBJTOOL_DEFERRED) $(multi-obj-m): private part-of-module := y $(multi-obj-m): %.o: %.mod FORCE $(call if_changed_rule,ld_multi_m) diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 0a4fdd8bd975d..3622237e41d2e 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -210,11 +210,9 @@ objtool-args-$(or $(CONFIG_GCOV_KERNEL),$(CONFIG_KCOV)) += --no-unreachable objtool-args-$(CONFIG_OBJTOOL_WERROR) += --werror objtool-args = $(objtool-args-y) \ - $(if $(delay-objtool), --link) \ + $(if $(CONFIG_OBJTOOL_DEFERRED), --link) \ $(if $(part-of-module), --module) -delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT),$(CONFIG_KLP_BUILD)) - cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@) cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index 24a3a4fd271c2..9bac917e8b819 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -30,15 +30,16 @@ endif # objtool for vmlinux.o # --------------------------------------------------------------------------- # -# For delay-objtool (IBT or LTO), objtool doesn't run on individual translation -# units. Instead it runs on vmlinux.o. +# For CONFIG_OBJTOOL_DEFERRED (IBT or LTO), objtool doesn't run on individual +# translation units. Instead it runs on vmlinux.o. # -# For !delay-objtool + CONFIG_NOINSTR_VALIDATION, it runs on both translation -# units and vmlinux.o, with the latter only used for noinstr/unret validation. +# For !CONFIG_OBJTOOL_DEFERRED + CONFIG_NOINSTR_VALIDATION, it runs on both +# translation units and vmlinux.o, with the latter only used for noinstr/unret +# validation. -objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) +objtool-enabled := $(or $(CONFIG_OBJTOOL_DEFERRED),$(CONFIG_NOINSTR_VALIDATION)) -ifeq ($(delay-objtool),y) +ifeq ($(CONFIG_OBJTOOL_DEFERRED),y) vmlinux-objtool-args-y += $(objtool-args-y) else vmlinux-objtool-args-$(CONFIG_OBJTOOL_WERROR) += --werror diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index f99e196abeea4..aa10867a04de2 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -60,8 +60,7 @@ vmlinux_link() # skip output file argument shift - if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT || - is_enabled CONFIG_KLP_BUILD; then + if is_enabled CONFIG_OBJTOOL_DEFERRED || is_enabled CONFIG_LTO_CLANG; then # Use vmlinux.o instead of performing the slow LTO link again. objs=vmlinux.o libs= -- 2.55.0