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 X-Spam-Level: X-Spam-Status: No, score=-22.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27314C43331 for ; Wed, 25 Mar 2020 23:13:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E82DB20737 for ; Wed, 25 Mar 2020 23:13:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="q2FsSrJX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727556AbgCYXNI (ORCPT ); Wed, 25 Mar 2020 19:13:08 -0400 Received: from mail-pj1-f73.google.com ([209.85.216.73]:43239 "EHLO mail-pj1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727389AbgCYXNI (ORCPT ); Wed, 25 Mar 2020 19:13:08 -0400 Received: by mail-pj1-f73.google.com with SMTP id i3so2824966pjx.8 for ; Wed, 25 Mar 2020 16:13:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=vYzRHAXTkQE8ShgnDZUpxP00w9EinAhnVmiKvXd/foI=; b=q2FsSrJXDpqfuBS5dk6JPgdvo0wd0sVkpC7LXX+qsUsfnNJ31JRkXM2KcjWClSiSDV L3qSepNYPIqEMhy1N2aXKWeTXTbTiMYqZP15NN/ToHeMNdq/EGjGsDhoqViMxgiyE5m2 xi+mX6gv+HaH28YiBTn59+rf4mF9HPFknk+hQ2nlozFrjj4dV8faD9Y/HnyUXszL+Ijr w9QkxblWDiMYzeAJwR18JvjgLcgsYhrtODqZTERNRgeAqwZwXEWE0e0uqoBBOeiK7BNy 3zihojs5+alZtFAu2ly/VfSb3cl2FCljwn0rkQH+Ue445Z7kl922+aYK1iPlvqxsq+EL vNrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=vYzRHAXTkQE8ShgnDZUpxP00w9EinAhnVmiKvXd/foI=; b=o2iq++BA/FAKzCaQNZAuMR+ZE9+dsk5X+WhctfYXZJFi/ScYdY6BoDrNkW0jScGd85 C7pU0dozsvLSCwfhZigAhdNaq4Ng3rcxjY5OxmDPZyDf/AWasLe7U1TZu4wdQOxoPLDj PWaZr2BobweuMYdpNljnquhrlvQC0lpnoMRKK4W9dk6evy31pv166Aa7Jbv2rPflVlKO gHmglOLByC2hAKe7W1GQ7zQFrmtedgFxt94lL9FfPDZG+N/6O32z4yQ20Vbjz2Efy51Q b7fkQq/yn4vuctZadyblnc0liQ918NaaKfu6gjqcV2U3H3kEch5UvrU+HTc5WuvWQPqu jhHw== X-Gm-Message-State: ANhLgQ0CFl0iW3LZQQ+ItiDD0EPlKp/CO8zShPnUBNwuQnaIfI0JKXp1 QVlARWkELfLKx7dUlgRXJ+atouiJ2NQSL+D7sFA= X-Google-Smtp-Source: ADFU+vsTMhvlq2oHM5hrfkOjva2zCgqgnZoK8S009erVEMvYNOBoVA8tEYNNRGUKKRCLH3IYwCqYPxM5MIrZlXQ7Pcw= X-Received: by 2002:a17:90b:124a:: with SMTP id gx10mr6250888pjb.117.1585177985586; Wed, 25 Mar 2020 16:13:05 -0700 (PDT) Date: Wed, 25 Mar 2020 16:12:49 -0700 Message-Id: <20200325231250.99205-1-ndesaulniers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.26.0.rc2.310.g2932bb562d-goog Subject: [PATCH] elfnote: mark all .note sections SHF_ALLOC From: Nick Desaulniers To: Thomas Gleixner , Andrew Morton Cc: clang-built-linux@googlegroups.com, Nick Desaulniers , Jeremy Fitzhardinge , Ilie Halip , Vincenzo Frascino , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ELFNOTE_START allows callers to specify flags for .pushsection assembler directives. All callsites but ELF_NOTE use "a" for SHF_ALLOC. For vdso's that explicitly use ELF_NOTE_START and BUILD_SALT, the same section is specified twice after preprocessing, once with "a" flag, once without. Example: .pushsection .note.Linux, "a", @note ; .pushsection .note.Linux, "", @note ; While GNU as allows this ordering, it warns for the opposite ordering, making these directives position dependent. We'd prefer not to precisely match this behavior in Clang's integrated assembler. Instead, the non __ASSEMBLY__ definition of ELF_NOTE uses __attribute__((section(".note.Linux"))) which is created with SHF_ALLOC, so let's make the __ASSEMBLY__ definition of ELF_NOTE consistent with C and just always use "a" flag. This allows Clang to assemble a working mainline (5.6) kernel via: $ make CC=clang AS=clang Link: https://github.com/ClangBuiltLinux/linux/issues/913 Cc: Jeremy Fitzhardinge Debugged-by: Ilie Halip Signed-off-by: Nick Desaulniers --- Ilie has further treewide cleanups: https://github.com/ihalip/linux/commits/elfnote This patch is the simplest to move us forwards. include/linux/elfnote.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/elfnote.h b/include/linux/elfnote.h index 594d4e78654f..69b136e4dd2b 100644 --- a/include/linux/elfnote.h +++ b/include/linux/elfnote.h @@ -54,7 +54,7 @@ .popsection ; #define ELFNOTE(name, type, desc) \ - ELFNOTE_START(name, type, "") \ + ELFNOTE_START(name, type, "a") \ desc ; \ ELFNOTE_END -- 2.26.0.rc2.310.g2932bb562d-goog