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=-10.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_MED,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 11D4EC43142 for ; Mon, 30 Jul 2018 21:34:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4E2820894 for ; Mon, 30 Jul 2018 21:34:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ttUwhsgI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4E2820894 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731971AbeG3XLe (ORCPT ); Mon, 30 Jul 2018 19:11:34 -0400 Received: from mail-io0-f201.google.com ([209.85.223.201]:33078 "EHLO mail-io0-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730815AbeG3XLd (ORCPT ); Mon, 30 Jul 2018 19:11:33 -0400 Received: by mail-io0-f201.google.com with SMTP id s14-v6so9891257ioc.0 for ; Mon, 30 Jul 2018 14:34:39 -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:content-transfer-encoding; bh=GSFhJJjXAKzwslV2aojDI50z4s/ItifdXUjanLyszkw=; b=ttUwhsgIUMC/pNurY8Q95D/T9JgNxVEFdxw5WmQj8pxw9cPi+6tJDJihkShWRv3Q4x jBQA0jODT73b1/N+glRBqP3xZMlgnH2nQ/9vaEGw+Q4DNb46JD14Q0oYxmKWMxujME0k 9GthLRRAD0lmtrwb/HsPWVuq8l+ix/JqrxMLR91H4L735xjBGQzrDPJ7P3+gcC/1wD0Z NonJj/h8VSDjQbzsTX506c/rqbunXXUmXtBzyUV1Bh36Hym77cHLhVVvQVr7uLwNNmnw m3ODUU1HZACxEfbxNVDqwYDzigs28nqkhac619+z7vHxsMF5uT+tBlJJ7qpEaASRF/EY y8vA== 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:content-transfer-encoding; bh=GSFhJJjXAKzwslV2aojDI50z4s/ItifdXUjanLyszkw=; b=MvaNYqgyS2qgppyK2HWR/7sSFRKjXvtEuDJ8JbFCyDNPrsntE89/i/EXRtbpGaF3G/ eFTZdSKEWKJqqOAGsqVZvajZvGOEuDbbSqXv8SvJLwo70aMVt2sRJJ5FwrW/+symZ8o+ T+WzNs4T9knUL1yobhfmX3eJuzpbLNsSq7h789Zpx5ShfadhW4pTh8s78ZvRjZoVL1z+ wgxwPe5gJMO5lcb0UGCTRmqvpoqpofENVlrPHQv6ctIjy/TF/Yne1VWEsnPB2WtkgySc 5W0NiKSOTFlxPw8szNG+gyh+ylKMZuZOVKMhZmPtyeL9qaOMbJLhoH/gd89zwGXVU1cR N3BA== X-Gm-Message-State: AOUpUlESEu3SMYnj8Iwne+tTCn6FIIjaDNh4TjrJMgfngHspNoTBSyZ+ sSo7PFQHF87kQXvwp/xpflXPkzRIDH39szPzWK8= X-Google-Smtp-Source: AAOMgpeZUMlCjsaH4mZlkR2Mnawsc3nzrQEMMQ8P3nheOcu/J4EpJs9j6CGTR8+x5yfarJSwakQIb148mvXS2OtnSH8= X-Received: by 2002:a24:7a51:: with SMTP id a78-v6mr461560itc.8.1532986478540; Mon, 30 Jul 2018 14:34:38 -0700 (PDT) Date: Mon, 30 Jul 2018 14:34:12 -0700 In-Reply-To: <20180730213412.242849-1-ndesaulniers@google.com> Message-Id: <20180730213412.242849-3-ndesaulniers@google.com> Mime-Version: 1.0 References: <20180730213412.242849-1-ndesaulniers@google.com> X-Mailer: git-send-email 2.18.0.345.g5c9ce644c3-goog Subject: [PATCH v2 2/2] kernel.h: Disable -Wreturn-stack-address for _THIS_IP_ From: Nick Desaulniers To: akpm@linux-foundation.org, natechancellor@gmail.com Cc: arnd@arndb.de, paul.burton@mips.com, christophe.leroy@c-s.fr, shorne@gmail.com, yamada.masahiro@socionext.com, keescook@chromium.org, mingo@kernel.org, gregkh@linuxfoundation.org, tglx@linutronix.de, rdunlap@infradead.org, bp@suse.de, neilb@suse.com, linux-kernel@vger.kernel.org, aryabinin@virtuozzo.com, dwmw@amazon.co.uk, sandipan@linux.vnet.ibm.com, linux@rasmusvillemoes.dk, paullawrence@google.com, andreyknvl@google.com, will.deacon@arm.com, ghackmann@android.com, stable@vger.kernel.org, ghackmann@google.com, mka@chromium.org, jpoimboe@redhat.com, wvw@google.com, avagin@openvz.org, Nick Desaulniers Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Starting with Clang-7.0, _THIS_IP_ generates -Wreturn-stack-address warnings for almost every translation unit. In general, I'd prefer to leave this on (returning the address of a stack allocated variable is in general a bad idea) and disable it only at whitelisted call sites. We can't do something like: #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wreturn-stack-address" #pragma clang diagnostic pop in a GNU Statement Expression or macro, hence we use _Pragma, which is its raison d'=C3=AAtre: https://gcc.gnu.org/onlinedocs/cpp/Pragmas.html We also can't use compiler specific pragma's without triggering -Werror=3Dunknown-pragmas in other compilers, so use __diag. Cc: stable@vger.kernel.org # 4.17, 4.14, 4.9, 4.4 Suggested-by: Nathan Chancellor Signed-off-by: Nick Desaulniers --- include/linux/kernel.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 941dc0a5a877..909bb771c0ca 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -168,7 +168,15 @@ =20 =20 #define _RET_IP_ (unsigned long)__builtin_return_address(0) -#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }= ) +#define _THIS_IP_ ( \ +{ \ + __label__ __here; \ + __diag_push() \ + __diag_ignore(CLANG, 7, "-Wreturn-stack-address", "") \ +__here: (unsigned long)&&__here; \ + __diag_pop() \ +} \ +) =20 #ifdef CONFIG_LBDAF # include --=20 2.18.0.345.g5c9ce644c3-goog