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 4FE23C433EF for ; Mon, 4 Apr 2022 21:28:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380324AbiDDVae (ORCPT ); Mon, 4 Apr 2022 17:30:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379582AbiDDRgc (ORCPT ); Mon, 4 Apr 2022 13:36:32 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27E61286E7 for ; Mon, 4 Apr 2022 10:34:36 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id gt4so3552843pjb.4 for ; Mon, 04 Apr 2022 10:34:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=V1fiQ+TpCWz9aW9batEAHSpfr5r9dyK3Q/lTwaH3lR0=; b=n5mRgSQ8y20acZ/nK6OhYxxGJzwZSGfgcaIV5gwWcarOIpZUaCExb23hDcba/FfujR xFNvpv34nq2Hj6fGtwvQQenG/CsfvSWly7w85pOa2sG503FmKvshqI9P5cFMoVE3Aar/ UQu5P8WN1WRQr6qVnpL2fGXvjFr5cmxhUxxebpUNcv68zXidJPUkPwuQpB2cgSdry9M0 eLkTMCOhfou4kVQgZxaauYZqxvKoMSlmivMsJ7IiJDCkOcBgoxX2LkJHmM3A/XGrPuQZ 2pPiCkDFuX+TqlPuqM3RY9B1nPG/O5uu9L/f2k9jXWu9RJ6qGXKz05KdOk77e14RcYjY VMzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=V1fiQ+TpCWz9aW9batEAHSpfr5r9dyK3Q/lTwaH3lR0=; b=FI7nWpAv607lQTOjbF+BBKbr/wPtnzjJNtlkQysulpWCsLYOD2uXegCVhT1WP1jz1F MVF18+VcZ+FsDEA71maZgN696V0gRWBD7K+jJw02tRnYUOxGOT8/Nd0WefwKgWi5vUvU R1COupYlFOM4ZRhX+ffHrMeUllqrWSMUbLZkoOp0AXgIpdDmvFVgt/VJb/s1NvnD814r 8mTW/EnO7gs4tbb8mqirPd4JbIj7paYrJRxVyIwG8bJgdOBnhsp1C0r56BGTpWqlcXY7 JuTgyafA1w4uL6FSXnEyzxXPxBxWxBKP3tSSF3UNGqf06KNRvembCGNUWZqe4QqhlkHH IhYQ== X-Gm-Message-State: AOAM530wyJbx7aXerJG+GRJaSPJW6P/yM8diQxECNAFRovjsnyIuzG/n UIrGVi5Uq62nU2rNLiv1VtEAXg== X-Google-Smtp-Source: ABdhPJwHq/HMWfqJNWl3Tmj7ZD7tbsm4BjEdWB/ICSYcy3kVA2KslfNYCV0z25OGCfSV48YcTJj1nA== X-Received: by 2002:a17:903:20c:b0:154:b58:d424 with SMTP id r12-20020a170903020c00b001540b58d424mr704902plh.45.1649093675449; Mon, 04 Apr 2022 10:34:35 -0700 (PDT) Received: from google.com ([2620:15c:211:202:9d5:9b93:ffb4:574a]) by smtp.gmail.com with ESMTPSA id f66-20020a62db45000000b004fa8a7b8ad3sm12748136pfg.77.2022.04.04.10.34.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Apr 2022 10:34:34 -0700 (PDT) Date: Mon, 4 Apr 2022 10:34:27 -0700 From: Nick Desaulniers To: Masahiro Yamada Cc: Masahiro Yamada , Arnd Bergmann , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, Greg Kroah-Hartman Subject: Re: [PATCH 2/8] kbuild: prevent exported headers from including , Message-ID: References: <20220404061948.2111820-1-masahiroy@kernel.org> <20220404061948.2111820-3-masahiroy@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Mon, Apr 04, 2022 at 12:41:54AM -0700, Christoph Hellwig wrote: > On Mon, Apr 04, 2022 at 03:19:42PM +0900, Masahiro Yamada wrote: > > If we can make kernel headers self-contained (that is, none of exported > > kernel headers includes system headers), we will be able to add the > > -nostdinc flag, but that is much far from where we stand now. This is something I'd like to see done. IMO, the kernel headers should be the independent variable of which the libc is the dependendent variable. Android's libc, Bionic, is making use of the UAPI headers. They are doing some rewriting of UAPI headers, but I'd like to see what needs to be upstreamed from there. I just noticed include/uapi/linux/libc-compat.h, which seems like a good place for such compat related issues. In particular, having UAPI_HEADER_TESTS depend on CC_CAN_LINK is something I think we can works towards removing. The header tests themselves don't link; they force a dependency on a prebuilt libc sysroot, and they only need the headers from the sysroot because of this existing circular dependency between kernel headers and libc headers. I'd be happy to be explicitly cc'ed on changes like this series, going forward. Masahiro, if there's parts you'd like me to help with besides just code review, please let me know how I can help. > > What is still missing for that?