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=-16.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 05D9AC433EF for ; Wed, 15 Sep 2021 14:03:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DECAF611C6 for ; Wed, 15 Sep 2021 14:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237230AbhIOOEv (ORCPT ); Wed, 15 Sep 2021 10:04:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233545AbhIOOEu (ORCPT ); Wed, 15 Sep 2021 10:04:50 -0400 Received: from mail-oo1-xc30.google.com (mail-oo1-xc30.google.com [IPv6:2607:f8b0:4864:20::c30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 94F9EC061574; Wed, 15 Sep 2021 07:03:31 -0700 (PDT) Received: by mail-oo1-xc30.google.com with SMTP id q26-20020a4adc5a000000b002918a69c8eeso904251oov.13; Wed, 15 Sep 2021 07:03:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=dXV0TdJQZj6j+f/Hi7EIzy0MEGNbxXGsvCh8JJLlODg=; b=WPi3IOT8Z+un52mSPLE4sfqcvjdnW6YB61L3883DmVLJCseKT0/X5+UxUhOCmGoe6Z HIGh4/nwJMlyK+3dCdARsx7O83eqW0mxZ8VZ0aedkBHAaEN7l82Gy6kEnotJu0yF+MU+ 5a+7S37ulW2eIr6nSMyrGUZyXeMv3h4t8ZlzhCuIPCpxyX7J/TepZavW275hbZyhW2Gk YOa17FQn9TO4Gk7XgljwpYzkzDT+C2SZhOQvgqFsx4nDUuzNklzbH8Hgi4XLuqrfB5c3 eMXBKePg1BOAfA5WW84beOgutATln1NmsNbVFEakI6+C4NMzrKEuxWlWU4otT5aApJjU fABw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:subject:to:cc:references:from:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=dXV0TdJQZj6j+f/Hi7EIzy0MEGNbxXGsvCh8JJLlODg=; b=lf/lxhHvy3JK2aJPkgydBUsoemjtuR+KI0105Nupx/NpGuVu7JvyzM8/6S6qSTxVBm +IiG59FHPSbr5em/T4oTXqk6LBm04h14aYmPlOEHC0QCXiARbVnBi54Ah9N7C5XwwhEd CPibysbq7N3TpOWbnKoHZBKlEL0/G7F9VNYeOhJXuub9kImyENfMwi5g1XRdUOomDNsH d2E0N4ZizxQ+mCZBzsmskqsIaFaPkbTB02/c1kPr//p3EOz9cWQxbQs7iB+UEIBzvnKj k+DvayEBKGAlHWj5N5whcl1QED2WexNkOcANgzEWnwgJ8qZ8vIreD+ltgXUi6kkTOJBo 5S7g== X-Gm-Message-State: AOAM531e8Bm3hWyaq8pqa1iIqIRKjkdExRXGL08OFZjzUTRAiM9P5rO/ uWN1KPgVr65ZW0dDMfcLbTaQwFxSQ0s= X-Google-Smtp-Source: ABdhPJxZWw0J/8Mllmga07N63Y8sT9KQNPV3ZJtz3dgQOrFH3hdHQmv0ainu2VlCw9qtyk8srn1muQ== X-Received: by 2002:a05:6820:555:: with SMTP id n21mr18699324ooj.56.1631714609412; Wed, 15 Sep 2021 07:03:29 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id v16sm11201oou.45.2021.09.15.07.03.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 15 Sep 2021 07:03:28 -0700 (PDT) Sender: Guenter Roeck Subject: Re: [PATCH v2 1/4] compiler.h: Introduce absolute_pointer macro To: Geert Uytterhoeven Cc: Linus Torvalds , Richard Henderson , Ivan Kokshaysky , Matt Turner , "James E . J . Bottomley" , Helge Deller , "David S . Miller" , Jakub Kicinski , alpha , Linux Kernel Mailing List , Parisc List , netdev , linux-sparse@vger.kernel.org References: <20210915035227.630204-1-linux@roeck-us.net> <20210915035227.630204-2-linux@roeck-us.net> From: Guenter Roeck Message-ID: Date: Wed, 15 Sep 2021 07:03:26 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On 9/15/21 12:13 AM, Geert Uytterhoeven wrote: > Hi Günter, > > On Wed, Sep 15, 2021 at 5:52 AM Guenter Roeck wrote: >> absolute_pointer() disassociates a pointer from its originating symbol >> type and context. Use it to prevent compiler warnings/errors such as >> >> drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe': >> ./arch/m68k/include/asm/string.h:72:25: error: >> '__builtin_memcpy' reading 6 bytes from a region of size 0 >> [-Werror=stringop-overread] >> >> Such warnings may be reported by gcc 11.x for string and memory operations >> on fixed addresses. >> >> Suggested-by: Linus Torvalds >> Signed-off-by: Guenter Roeck >> --- >> v2: No change >> >> include/linux/compiler.h | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/include/linux/compiler.h b/include/linux/compiler.h >> index b67261a1e3e9..3d5af56337bd 100644 >> --- a/include/linux/compiler.h >> +++ b/include/linux/compiler.h >> @@ -188,6 +188,8 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, >> (typeof(ptr)) (__ptr + (off)); }) >> #endif >> >> +#define absolute_pointer(val) RELOC_HIDE((void *)(val), 0) > > I guess we're not worried about "val" being evaluated multiple > times inside RELOC_HIDE(), as this is mainly intended for constants? > No, we are not. It is quite similar to RELOC_HIDE() in that regard. Guenter