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 6510EC433F5 for ; Thu, 10 Feb 2022 01:26:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232344AbiBJB0c (ORCPT ); Wed, 9 Feb 2022 20:26:32 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:52968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232135AbiBJB0Z (ORCPT ); Wed, 9 Feb 2022 20:26:25 -0500 Received: from condef-06.nifty.com (condef-06.nifty.com [202.248.20.71]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E15D520192; Wed, 9 Feb 2022 17:26:06 -0800 (PST) Received: from conssluserg-06.nifty.com ([10.126.8.85])by condef-06.nifty.com with ESMTP id 21A0UaTB024452; Thu, 10 Feb 2022 09:30:36 +0900 Received: from mail-pf1-f179.google.com (mail-pf1-f179.google.com [209.85.210.179]) (authenticated) by conssluserg-06.nifty.com with ESMTP id 21A0U6Su029232; Thu, 10 Feb 2022 09:30:07 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-06.nifty.com 21A0U6Su029232 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1644453007; bh=6klY6ywSHDTIAmjF9MCEJbiIQSicqR7O8sRNcdznk98=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=r6P2WkeMfp/H3RXMD6DzcwlV9NwBjLEOXZoRASN2wuKbY0r2MfWcnjJFQYO20li4Z r36l9GLY/xAc5J2Xai+1gb4fws1qxfu6BuO6/WQ6/VZxkBr7BlJBPFIAD3WZ16h6Os fHszajb7da46jy/QH+686vigTFIWspGksiC8RALLtvMu8fDo7Ryii78/iCBfiU6KxS k+FpDbGKEhCCv3GsUK9BVUV+Bnm56NcYqRWxiA2HEKFs43S7TNz1xxJxtw9O2fVQW+ tL5oQWFHYzyB1WUnCogTyewfahMWeYZvoPuSpXdt16dfW5Su55XpePvQsJx2gZVbi0 hCyQOR7VmrG8g== X-Nifty-SrcIP: [209.85.210.179] Received: by mail-pf1-f179.google.com with SMTP id i186so7397347pfe.0; Wed, 09 Feb 2022 16:30:07 -0800 (PST) X-Gm-Message-State: AOAM530EGvzi3pUqKjkE+P0rwz+KbuwTG/klEVo0NQnuSx5mgV0BomEF Z3Rswc2r6BXOW5rgZciOVW2dA1qmkXKp+ZzZsyQ= X-Google-Smtp-Source: ABdhPJy9PxQxyofxPgV6A6DkaBe7h5z+1tcTNPVaCvhahGvMNZ8PUFa33IO9YCS+eHepbhDA9aj4Q/bzp9Ylq1Q/eNY= X-Received: by 2002:a05:6a00:240a:: with SMTP id z10mr4954154pfh.68.1644453006311; Wed, 09 Feb 2022 16:30:06 -0800 (PST) MIME-Version: 1.0 References: <20220112224342.958358-1-quic_eberman@quicinc.com> <20220201213542.2808035-1-quic_eberman@quicinc.com> In-Reply-To: From: Masahiro Yamada Date: Thu, 10 Feb 2022 09:29:31 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3] kbuild: Add environment variables for userprogs flags To: Nick Desaulniers Cc: Fangrui Song , Michal Marek , Nathan Chancellor , Matthias Maennich , Linux Kbuild mailing list , Linux Kernel Mailing List , llvm@lists.linux.dev, Elliot Berman Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 9, 2022 at 7:53 AM Nick Desaulniers wrote: > > On Tue, Feb 1, 2022 at 1:38 PM Nick Desaulniers wrote: > > > > On Tue, Feb 1, 2022 at 1:36 PM Elliot Berman wrote: > > > > > > Allow additional arguments be passed to userprogs compilation. > > > Reproducible clang builds need to provide a sysroot and gcc path to > > > ensure same toolchain is used across hosts. KCFLAGS is not currently > > > > ^ ensure the same (maybe Masahiro can fix that up locally when applying) > > Masahiro, > What are your thoughts on this patch? I think this would help Android > define a musl or bionic sysroot for CC_CAN_LINK and ultimately > UAPI_HEADER_TEST support. Sorry for delay. Applied with two fixups in the commit log: ensure same -> ensure the same Clang 13+ might detect -> Clang might detect > > > > > used for any user programs compilation, so add new USERCFLAGS and > > > USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS. > > > > > > Clang 13+ might detect GCC installation on hosts which have it installed > > > to a default location in /. With addition of these environment > > > variables, you can specify flags such as: > > > > > > $ make USERCFLAGS=--sysroot=/path/to/sysroot > > > > > > This can also be used to specify different sysroots such as musl or > > > bionic which may be installed on the host in paths that the compiler > > > may not search by default. > > > > > > Signed-off-by: Elliot Berman > > > > Thanks for the patch! > > Reviewed-by: Nick Desaulniers > > > > > --- > > > > > > Changes since v2: > > > - Incorporated Nick's suggestions: > > > - Addressed docs and commit text comments > > > - Introduced KBUILD_USERHOSTCFLAGS as suggested > > > > > > Documentation/kbuild/kbuild.rst | 11 +++++++++++ > > > Documentation/kbuild/makefiles.rst | 2 ++ > > > Makefile | 10 ++++++---- > > > init/Kconfig | 8 ++++---- > > > usr/include/Makefile | 3 +++ > > > 5 files changed, 26 insertions(+), 8 deletions(-) > > > > > > diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst > > > index 2d1fc03d346e..ef19b9c13523 100644 > > > --- a/Documentation/kbuild/kbuild.rst > > > +++ b/Documentation/kbuild/kbuild.rst > > > @@ -77,6 +77,17 @@ HOSTLDLIBS > > > ---------- > > > Additional libraries to link against when building host programs. > > > > > > +.. _userkbuildflags: > > > + > > > +USERCFLAGS > > > +---------- > > > +Additional options used for $(CC) when compiling userprogs. > > > + > > > +USERLDFLAGS > > > +----------- > > > +Additional options used for $(LD) when linking userprogs. userprogs are linked > > > +with CC, so $(USERLDFLAGS) should include "-Wl," prefix as applicable. > > > + > > > KBUILD_KCONFIG > > > -------------- > > > Set the top-level Kconfig file to the value of this environment > > > diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst > > > index b008b90b92c9..11a296e52d68 100644 > > > --- a/Documentation/kbuild/makefiles.rst > > > +++ b/Documentation/kbuild/makefiles.rst > > > @@ -982,6 +982,8 @@ The syntax is quite similar. The difference is to use "userprogs" instead of > > > > > > When linking bpfilter_umh, it will be passed the extra option -static. > > > > > > + From command line, :ref:`USERCFLAGS and USERLDFLAGS ` will also be used. > > > + > > > 5.4 When userspace programs are actually built > > > ---------------------------------------------- > > > > > > diff --git a/Makefile b/Makefile > > > index 45278d508d81..1d0172449355 100644 > > > --- a/Makefile > > > +++ b/Makefile > > > @@ -431,11 +431,12 @@ HOSTCC = gcc > > > HOSTCXX = g++ > > > endif > > > > > > -export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ > > > - -O2 -fomit-frame-pointer -std=gnu89 > > > -export KBUILD_USERLDFLAGS := > > > +KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \ > > > + -O2 -fomit-frame-pointer -std=gnu89 > > > +KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS) > > > +KBUILD_USERLDFLAGS := $(USERLDFLAGS) > > > > > > -KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) > > > +KBUILD_HOSTCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS) > > > KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) > > > KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS) > > > KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS) > > > @@ -530,6 +531,7 @@ export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AW > > > export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX > > > export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD > > > export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE > > > +export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS > > > > > > export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS > > > export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE > > > diff --git a/init/Kconfig b/init/Kconfig > > > index f2ae41e6717f..164706c38e8b 100644 > > > --- a/init/Kconfig > > > +++ b/init/Kconfig > > > @@ -62,13 +62,13 @@ config LLD_VERSION > > > > > > config CC_CAN_LINK > > > bool > > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT > > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag)) > > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT > > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag)) > > > > > > config CC_CAN_LINK_STATIC > > > bool > > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag) -static) if 64BIT > > > - default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m32-flag) -static) > > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT > > > + default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static) > > > > > > config CC_HAS_ASM_GOTO > > > def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC)) > > > diff --git a/usr/include/Makefile b/usr/include/Makefile > > > index 1c2ae1368079..0322e567dc1e 100644 > > > --- a/usr/include/Makefile > > > +++ b/usr/include/Makefile > > > @@ -12,6 +12,9 @@ UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration > > > # It is here just because CONFIG_CC_CAN_LINK is tested with -m32 or -m64. > > > UAPI_CFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS)) > > > > > > +# USERCFLAGS might contain sysroot location for CC. > > > +UAPI_CFLAGS += $(USERCFLAGS) > > > + > > > override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include > > > > > > # The following are excluded for now because they fail to build. > > > -- > > > 2.25.1 > > > > > > > > > -- > > Thanks, > > ~Nick Desaulniers > > > > -- > Thanks, > ~Nick Desaulniers -- Best Regards Masahiro Yamada