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=-17.8 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,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 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 E1C1CC433E2 for ; Tue, 1 Sep 2020 00:23:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5DD120E65 for ; Tue, 1 Sep 2020 00:23:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="vXbvBt0y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726386AbgIAAXi (ORCPT ); Mon, 31 Aug 2020 20:23:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726192AbgIAAXg (ORCPT ); Mon, 31 Aug 2020 20:23:36 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BEF8C061575 for ; Mon, 31 Aug 2020 17:23:36 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id w1so7332740qto.4 for ; Mon, 31 Aug 2020 17:23:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=OpCRtcsPpFRLic5hvjC2zaEKYM15+afAD1UpP9e19yY=; b=vXbvBt0ydWJpSbrePzJiwyZF3yTIoFQqhrG+f71LvHy1hBFePv6+9A0LM2YOL/J1pH UenXtaEO3Swyb6owdtq+v60ovlxyeuGW63KCw9s7UshgzIGFDweCmb93nVehvu09zoj7 9vW+O4MLF9sHxq/G2EHutXhyTN9ARP4A1dhnm1cOT+wCb9VixqmN9Te8L17J8QGj3WzY Ts1u9PaCBq8evxOj696mLzImp6zv3GN9xylZzOpLnZ1ZekH9W+BcOIR9j6CNCoWeNXfW sd4E11kGHUHuZUqqYUPuRcsfXDD4sf6fwa/58oTH9CaY0OppljOHfSny2ohj0+7kbKb4 jruQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=OpCRtcsPpFRLic5hvjC2zaEKYM15+afAD1UpP9e19yY=; b=oX7IX737XI39DfctHwEX8Rvxatwhlny8kWjN7kKirr6FF98GWpLpd85YvR3kbUjQj1 3JUgAmqsrSEWCm1I+SX5186crzXoFUDKbc8AbMhYIP4qStN9qtMVTsy6Mn9ZoW++Gwn2 Z/JiBNQjznGFmnsTvC1exSfRF5h1N5ZiDBjckrUIX1Mk1y99EpM1B33XwYlc1L5HYSVn CrW9RvTlbG21oqGNswvoTrYUbq0Bu70A3vB1kCSqTzUZEHfIhEjFPGj+Q3e6VnSLRk8e VTMbHjshmY3Q/+YbLlac6bW391uoytH60ArTtKqFosvMMgyRNVTtJFuPFmuW+DCrpIiz BYgg== X-Gm-Message-State: AOAM5314DlREynmZxpkYRuxLw4SET/mzKPtyFPmHDP7dCM5Mpgou37lp CQO2qudeLSqSRLWze/eQxJdqLwGgaT8eiblWLb8= X-Google-Smtp-Source: ABdhPJzmB9zUGYUYDfr5ruRvfjynhXPf5vtI696h1nnKit+Ix1PRIw2niAYqN5275XDAgcB2xOsAo/RhfHQwLmqkv+A= X-Received: from ndesaulniers1.mtv.corp.google.com ([2620:15c:211:202:f693:9fff:fef4:4d25]) (user=ndesaulniers job=sendgmr) by 2002:a0c:a789:: with SMTP id v9mr923919qva.2.1598919815516; Mon, 31 Aug 2020 17:23:35 -0700 (PDT) Date: Mon, 31 Aug 2020 17:23:21 -0700 In-Reply-To: <20200901002326.1137289-1-ndesaulniers@google.com> Message-Id: <20200901002326.1137289-3-ndesaulniers@google.com> Mime-Version: 1.0 References: <20200901002326.1137289-1-ndesaulniers@google.com> X-Mailer: git-send-email 2.28.0.402.g5ffc5be6b7-goog Subject: [PATCH v2 2/7] Revert "kbuild: disable clang's default use of -fmerge-all-constants" From: Nick Desaulniers To: Andrew Morton Cc: Kees Cook , Miguel Ojeda , Nathan Chancellor , Sedat Dilek , Marco Elver , Andrey Konovalov , Masahiro Yamada , clang-built-linux@googlegroups.com, Daniel Borkmann , Alexei Starovoitov , Will Deacon , Vincenzo Frascino , linux-kernel@vger.kernel.org, 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 This reverts commit 87e0d4f0f37fb0c8c4aeeac46fff5e957738df79. This was fixed in clang-6; the minimum supported version of clang in the kernel is clang-10 (10.0.1). Link: https://reviews.llvm.org/rL329300. Link: https://github.com/ClangBuiltLinux/linux/issues/9 Suggested-by: Nathan Chancellor Signed-off-by: Nick Desaulniers --- Makefile | 9 --------- 1 file changed, 9 deletions(-) diff --git a/Makefile b/Makefile index 37739ee53f27..144ac6a073ff 100644 --- a/Makefile +++ b/Makefile @@ -932,15 +932,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized) # disable invalid "can't wrap" optimizations for signed / pointers KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow) -# clang sets -fmerge-all-constants by default as optimization, but this -# is non-conforming behavior for C and in fact breaks the kernel, so we -# need to disable it here generally. -KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants) - -# for gcc -fno-merge-all-constants disables everything, but it is fine -# to have actual conforming behavior enabled. -KBUILD_CFLAGS += $(call cc-option,-fmerge-constants) - # Make sure -fstack-check isn't enabled (like gentoo apparently did) KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,) -- 2.28.0.402.g5ffc5be6b7-goog