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 4EC7FECAAA6 for ; Fri, 26 Aug 2022 18:22:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232338AbiHZSWz (ORCPT ); Fri, 26 Aug 2022 14:22:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344659AbiHZSWe (ORCPT ); Fri, 26 Aug 2022 14:22:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37AB6E398C; Fri, 26 Aug 2022 11:21:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2B0AC61D23; Fri, 26 Aug 2022 18:21:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9888C433C1; Fri, 26 Aug 2022 18:21:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661538105; bh=P+hcLIrD/F79al7x8aLPgb1+lPQ8gMRGke9HgDVnG/Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Z3yHxCqi3J/rAwrRsJLFeT4icMMpxhb3OpvWJ9DJWaYvDvGzOL+TCnbC6/PgoVUUR XNdnqO731drISisd0y80CmEDHwyJVand2PAe3oPWitY9mWShrepAIMgWIWhJXXgNbR kKKlkizBFCHMEjaZGg8HuPrylFmSMtJM0ce+ORSfrUpoqjbDxevVp9TebNHvX/AKv9 DQcmWDKBGCK144wO/AvrTXOLl1C5+rgX6/OzH7j2Sdc8y1t5zCewgTCWvae/9imSU6 zov6lclxSgDpvuhAKX5LJgBCEIXC3ILbKJ7kbLCfCEjrfwFipx1L1Tcb7tyVZ7UOKx FCfN7vdTOPObg== Date: Fri, 26 Aug 2022 11:21:43 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Masahiro Yamada , Michal Marek , Tom Rix , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, x86@kernel.org, Dmitrii Bundin , Fangrui Song , Alexey Alexandrov , Bill Wendling , Greg Thelen Subject: Re: [PATCH 1/3] Makefile.compiler: s/KBUILD_CFLAGS/KBUILD_AFLAGS/ for as-option Message-ID: References: <20220826181035.859042-1-ndesaulniers@google.com> <20220826181035.859042-2-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220826181035.859042-2-ndesaulniers@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Nick, I think the title would be a little more readable if it was: Makefile.compiler: Use KBUILD_AFLAGS for as-option On Fri, Aug 26, 2022 at 11:10:33AM -0700, Nick Desaulniers wrote: > as-instr uses KBUILD_AFLAGS, but as-option uses KBUILD_CFLAGS. This can > cause as-option to fail unexpectedly because clang will emit > -Werror,-Wunused-command-line-argument for various -m and -f flags for > assembler sources. > > Callers of as-option (and as-instr) likely want to be adding flags to > KBUILD_AFLAGS/aflags-y, not KBUILD_CFLAGS/cflags-y. > > Link: https://github.com/ClangBuiltLinux/linux/issues/1699 > Signed-off-by: Nick Desaulniers > --- > arch/x86/boot/compressed/Makefile | 5 +++-- > scripts/Makefile.compiler | 6 +++--- > 2 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile > index 35ce1a64068b..fb3db714a028 100644 > --- a/arch/x86/boot/compressed/Makefile > +++ b/arch/x86/boot/compressed/Makefile > @@ -48,8 +48,6 @@ KBUILD_CFLAGS += -Wno-pointer-sign > KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) > KBUILD_CFLAGS += -fno-asynchronous-unwind-tables > KBUILD_CFLAGS += -D__DISABLE_EXPORTS > -# Disable relocation relaxation in case the link is not PIE. > -KBUILD_CFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no) > KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h > > # sev.c indirectly inludes inat-table.h which is generated during > @@ -58,6 +56,9 @@ KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h > CFLAGS_sev.o += -I$(objtree)/arch/x86/lib/ > > KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ > +# Disable relocation relaxation in case the link is not PIE. > +KBUILD_AFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no) > + Commit 09e43968db40 ("x86/boot/compressed: Disable relocation relaxation") added this to address https://github.com/ClangBuiltLinux/linux/issues/1121, is it correct to move it to only being used for the .S files in arch/x86/boot/compressed? > GCOV_PROFILE := n > UBSAN_SANITIZE :=n > > diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler > index 94d0d40cddb3..d1739f0d3ce3 100644 > --- a/scripts/Makefile.compiler > +++ b/scripts/Makefile.compiler > @@ -29,13 +29,13 @@ try-run = $(shell set -e; \ > fi) > > # as-option > -# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,) > +# Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,) > > as-option = $(call try-run,\ > - $(CC) $(KBUILD_CFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) > + $(CC) $(KBUILD_AFLAGS) $(1) -c -x assembler /dev/null -o "$$TMP",$(1),$(2)) > > # as-instr > -# Usage: cflags-y += $(call as-instr,instr,option1,option2) > +# Usage: aflags-y += $(call as-instr,instr,option1,option2) > > as-instr = $(call try-run,\ > printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3)) > -- > 2.37.2.672.g94769d06f0-goog >