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=-11.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=no 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 E529DC76190 for ; Thu, 25 Jul 2019 20:07:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BBA4522CC2 for ; Thu, 25 Jul 2019 20:07:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="L+koLszY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726663AbfGYUHM (ORCPT ); Thu, 25 Jul 2019 16:07:12 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:50829 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726595AbfGYUHM (ORCPT ); Thu, 25 Jul 2019 16:07:12 -0400 Received: by mail-qt1-f201.google.com with SMTP id g30so45319335qtm.17 for ; Thu, 25 Jul 2019 13:07:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Ty05lRNnYEjxTaLhAlpE2gx2Zy7GWIE7L8QY/O06f/I=; b=L+koLszYgKU+7K9nKDi+EHeoRBBciyMOAI5YEVDbvAZ5G3sIs6JTFjtTJIKilccaLM c7LKP5MOeEt+hia2yo1iQh4XLA9TafkU+mdvYwPdkPODSqO2y7BTRagZkSdwWlpDwsfv b3exmk8ntSWX3XgsSuxyvD8gVy/Y/AljXpAJOO0sDR4KHMuZS1fbDY8x9klvQJCp8GfA ZfDHP6vPqBOrL+4vt6xcTU1ObkYGEbhgHrlUNYk5pgEDg7H5i9PUwT4QaRNoVxIms3WD +SalUPYER3CuQHjiTf9iexCPkW4BtXzvmrmqw613+y62lk/Lulg3pCCrGaZCZg8HnEei 7v5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Ty05lRNnYEjxTaLhAlpE2gx2Zy7GWIE7L8QY/O06f/I=; b=EHqvdwPLDhubFGXDL3Wd12yRjR68lMmXVzeRZzx7oilhXtHhP647ztONetX6MwResn CbrAdpVx92ngy5e/XmyaD7IPHtm1XbteFLGlhmVTJFj6UaHaWhddMgd7Treq/GqHhl7r ijjag2mxMHgZ7GqhGYOkY9C0wOHno/S680Mf6sC8DkB1fVS+tV2dEqYkf1uxezQV3dBm TwodYLcR7JNsFSt1fAwbDLJ7GPdSrUfnfZHsTsgaNbRV/GPE3tvwMhAmz3WHRPYVpqjr NzHaxzKwr3EEe8r6luYr09ERDHE8zHU/GiiNEnaaWXJwjv3EXGQDBWmbA8qBsxwSkL9Z Z8+Q== X-Gm-Message-State: APjAAAVBt55S/E+UXMDQ4H3NDSJKAHfQZ+xVHLLx4LNhALAzS3XCY7zE 3fTKdn2vbaLBf1uQK7/I6U6QhGIhaPVeTmnv9OY= X-Google-Smtp-Source: APXvYqw0907duddRtb4OUF5TewdHeasj/6+RTAfVpkbxz1rCPgrD2wgxG8RM7Saw1zlhKxYj72Ufj9JOySJ+X98mqbY= X-Received: by 2002:a05:6214:601:: with SMTP id z1mr47731460qvw.197.1564085231149; Thu, 25 Jul 2019 13:07:11 -0700 (PDT) Date: Thu, 25 Jul 2019 13:06:19 -0700 In-Reply-To: <20190725200625.174838-1-ndesaulniers@google.com> Message-Id: <20190725200625.174838-3-ndesaulniers@google.com> Mime-Version: 1.0 References: <20190725200625.174838-1-ndesaulniers@google.com> X-Mailer: git-send-email 2.22.0.709.g102302147b-goog Subject: [PATCH v4 0/2] Support kexec/kdump for clang built kernel From: Nick Desaulniers To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de Cc: peterz@infradead.org, clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org, yamada.masahiro@socionext.com, Nick Desaulniers 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 1. Reuse the implementation of memcpy and memset instead of relying on __builtin_memcpy and __builtin_memset as it causes infinite recursion in Clang (at any opt level) or GCC at -O2. 2. Don't reset KBUILD_CFLAGS, rather filter CONFIG_FUNCTION_TRACER, CONFIG_STACKPROTECTOR, and CONFIG_STACKPROTECTOR_STRONG flags via `CFLAGS_REMOVE_.o' A good test of this series (besides boot testing a kexec kernel): * There should be no undefined symbols in arch/x86/purgatory/purgatory.ro: $ nm arch/x86/purgatory/purgatory.ro particularly `warn`, `bcmp`, `__stack_chk_fail`, `memcpy` or `memset`. * `-pg`, `-fstack-protector`, `-fstack-protector-strong` should not be added to the command line for the c source files under arch/x86/purgatory/ when compiling with CONFIG_FUNCTION_TRACER=y, CONFIG_STACKPROTECTOR=y, and CONFIG_STACKPROTECTOR_STRONG=y. V4 of: https://lkml.org/lkml/2019/7/23/864 Nick Desaulniers (2): x86/purgatory: do not use __builtin_memcpy and __builtin_memset x86/purgatory: use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS arch/x86/boot/string.c | 7 +++++++ arch/x86/purgatory/Makefile | 29 ++++++++++++++++++++++++----- arch/x86/purgatory/purgatory.c | 6 ++++++ arch/x86/purgatory/string.c | 23 ----------------------- 4 files changed, 37 insertions(+), 28 deletions(-) delete mode 100644 arch/x86/purgatory/string.c -- 2.22.0.709.g102302147b-goog