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,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 81874FD21E1 for ; Mon, 30 Jul 2018 17:06:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 280D220892 for ; Mon, 30 Jul 2018 17:06:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="VFIGoRxH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 280D220892 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 S1727474AbeG3Sm0 (ORCPT ); Mon, 30 Jul 2018 14:42:26 -0400 Received: from mail-vk0-f73.google.com ([209.85.213.73]:45639 "EHLO mail-vk0-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726762AbeG3Sm0 (ORCPT ); Mon, 30 Jul 2018 14:42:26 -0400 Received: by mail-vk0-f73.google.com with SMTP id l5-v6so5616384vkd.12 for ; Mon, 30 Jul 2018 10:06:30 -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 :content-transfer-encoding; bh=Zhd9brlUSU3VJSV9/oY0K6ohjn54GHCy8fO4/WEPHqo=; b=VFIGoRxHER+0LT4MJmafU4eevLxk039xJHN/613o1L0fblD7tl/6KD8+Idp/ickzeN gH7kQoaclbNNJV5G/Y0VY9jlXqmdDUUWLW21nWzT4kyUjC0eky0Q5NsqLScLpMXFo5QZ PKLWdWVFGJ2WdUonwLxat0blMohH5h4RE14Z641bwcgNBQwQi68MfUcvg/G8KAXWcevM YgUbaluiJPKaN0KRrUIAbwN91+JZ/29D35B7RQNpYr6/hKH0OEZmkInYjFtYKsYNv/HG QV5LISwj0LVchkUu+kIXd5rPrFquzJnD4LReYnCEIqHugt3P3dV/1kz2p86vpWWC2oqg SJAg== 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 :content-transfer-encoding; bh=Zhd9brlUSU3VJSV9/oY0K6ohjn54GHCy8fO4/WEPHqo=; b=mIwJAnyUmqeM/pPzISv84yKdIydUfyVnmnELwOERC3z+LUPyltsALT80x9nl1FU7qV hOT18jJFXj9v/pZ5p9WB/rwWEJSl4kcsoOHC2D1Iyh/+2DX8LM+yxc5Keo51v2fZ+0B7 k4M8kDHMYzBismDg0rBx72Xmps71rO7/68IYhVRUUrkPBwrYciSDpqOk9TGF9UrP9FdX JfOphxoHM5Cm66qm0UOLAUwPxsFVE1B54CXMbDLRnnjZF05ThuhQsPI8fWpfyEMAA6fQ 5QlQ3aQNfV4O8dJEq26/JCPswaI4SLqCzisa3oRxetkeuo9wPP3pvihCJHr+TPtTaz39 mUPw== X-Gm-Message-State: AOUpUlGSmzG0/pPiabpz/E7qi3NJEVVuAnehQwa3iDEpyjwJ2da2JS9k g7C0m7WH9eIzbdCv1r19hjJ2DNuuLDRZACCrrmE= X-Google-Smtp-Source: AAOMgpd9lSWOGLqmPeCiOhqJJlY9+jY2MlAjPOtPqh3BUXEbRv2W6HT4NIUey8nsNhjXKupzGLH1uGyP6zjZGyeV0Tk= X-Received: by 2002:a1f:ae84:: with SMTP id x126-v6mr8762108vke.38.1532970390260; Mon, 30 Jul 2018 10:06:30 -0700 (PDT) Date: Mon, 30 Jul 2018 10:06:20 -0700 Message-Id: <20180730170622.99349-1-ndesaulniers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.18.0.345.g5c9ce644c3-goog Subject: [PATCH] kernel.h: Disable -Wreturn-stack-address for _THIS_IP_ From: Nick Desaulniers To: akpm@linux-foundation.org Cc: mka@chromium.org, ghackmann@android.com, ghackmann@google.com, Nick Desaulniers , stable@vger.kernel.org, Kees Cook , Ingo Molnar , Greg Kroah-Hartman , Josh Poimboeuf , Wei Wang , Masahiro Yamada , Randy Dunlap , NeilBrown , linux-kernel@vger.kernel.org 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 Cc: stable@vger.kernel.org # 4.17, 4.14, 4.9, 4.4 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..5906f5727f90 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_ ( \ +{ \ + _Pragma("clang diagnostic push") \ + _Pragma("clang diagnostic ignored \"-Wreturn-stack-address\"") \ + __label__ __here; \ +__here: (unsigned long)&&__here; \ + _Pragma("clang diagnostic pop") \ +} \ +) =20 #ifdef CONFIG_LBDAF # include --=20 2.18.0.233.g985f88cf7e-goog