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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 728AEC433F4 for ; Sat, 1 Sep 2018 12:12:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20DBA2083C for ; Sat, 1 Sep 2018 12:12:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qh0/rviA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20DBA2083C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.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 S1727469AbeIAQYK (ORCPT ); Sat, 1 Sep 2018 12:24:10 -0400 Received: from mail-qt0-f195.google.com ([209.85.216.195]:37361 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726991AbeIAQYK (ORCPT ); Sat, 1 Sep 2018 12:24:10 -0400 Received: by mail-qt0-f195.google.com with SMTP id n6-v6so17409717qtl.4 for ; Sat, 01 Sep 2018 05:12:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=sMr3dAP+bUmWzlY9z8YGxCFK8ma18tf1A6rP6051FgU=; b=qh0/rviApsYIFuZigGI8KmW801ttK6MI5foNZCZ7A3dRpporwplZez7fxw0zn4r/aE r2foeHjYUIEFlTo3wiiAeQSUsUjADMTpg7OP6wWrXalVSenAw9CaOFwIuLpDgUWJ1h6C OjAnTmpT+g+3z4xbGvm+DuGtBvVB4fJAzCztIMR1VXyVtboF8EXu5T4auQY1XushhzNp 4EB9+OuqQvZElZy8JQCHeguYFR0eJT7JgKTsyPnIhSlOv98phjbcGxb2uQxc/18iWfPi RGWZ4S8+9WBmFPyiXuoob+bW+oE6gF1rEGdWyVrTfPOps5l3juSNdy8kAe9Dvvz/Tgik BEUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=sMr3dAP+bUmWzlY9z8YGxCFK8ma18tf1A6rP6051FgU=; b=tTsm6eRNtzi0dH56OH2k/vBHzMs2VDrcgYFnrLx9Pih3pzr4iGOIOAwJlbEo0p/40J o9O7gjwX2qlSIgxLNaVwFmg8UUqETlrIIK8ezOd3VPEJX3nQXJyJ4Gd6Mcdwy3iuhslz unn3CUpGkJ3iiP7WiDUBFS8sya9QDvhnHPM93OqnuUV+8JBOZnlrQPmV0RgaAYxzCVh4 vPTvXw+D7xXo4O4hLmIGegj1X9li5D3N//5tarrt0jRw0nFLOFdTX3KMkEuWY2GVG+I0 lJXlh0KTlsAMsDnJviFkYyBHMopCPwjLkJWQWxjiWDbZGoUTkiMskJxkNKuB9Ff95ZIz NeTA== X-Gm-Message-State: APzg51DhgbQ4buBhUmKBIP9OssrDfIL+cO/nlSjx+BbJU98odtDbHk/e A7LwnBEip42vnECZsEH5xSEUjNE6uug1qkBsgos= X-Google-Smtp-Source: ANB0VdZSseOl4S+DSPQM22bE8T4vshlZyXfrvNsdBZOoJtSH8Jp+ou8F4suKQgWBhVUyb25mxwEmmVRIOCZX4KEzi88= X-Received: by 2002:ac8:4304:: with SMTP id z4-v6mr19022501qtm.295.1535803939607; Sat, 01 Sep 2018 05:12:19 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:aed:2291:0:0:0:0:0 with HTTP; Sat, 1 Sep 2018 05:11:59 -0700 (PDT) In-Reply-To: <20180901091738.73dzegdenvla5crf@ltop.local> References: <20180831170514.24665-1-miguel.ojeda.sandonis@gmail.com> <20180831170514.24665-4-miguel.ojeda.sandonis@gmail.com> <20180901091738.73dzegdenvla5crf@ltop.local> From: Miguel Ojeda Date: Sat, 1 Sep 2018 14:11:59 +0200 Message-ID: Subject: Re: [PATCH 4/7] Compiler Attributes: homogenize __must_be_array To: Luc Van Oostenryck Cc: Linus Torvalds , linux-kernel , Eli Friedman , Christopher Li , Kees Cook , Ingo Molnar , Geert Uytterhoeven , Arnd Bergmann , Greg Kroah-Hartman , Masahiro Yamada , Joe Perches , Dominique Martinet , 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 Hi Luc, On Sat, Sep 1, 2018 at 11:17 AM, Luc Van Oostenryck wrote: > On Fri, Aug 31, 2018 at 07:05:11PM +0200, Miguel Ojeda wrote: >> Different definitions of __must_be_array: >> >> * gcc: disabled for __CHECKER__ >> diff --git a/include/linux/compiler.h b/include/linux/compiler.h >> index e0e55eb3f242..e4a702f99e50 100644 >> --- a/include/linux/compiler.h >> +++ b/include/linux/compiler.h >> @@ -357,4 +357,11 @@ static inline void *offset_to_ptr(const int *off) >> compiletime_assert(__native_word(t), \ >> "Need native word sized stores/loads for atomicity.") >> >> +#ifdef __CHECKER__ >> +#define __must_be_array(a) 0 >> +#else >> +/* &a[0] degrades to a pointer: a different type from an array */ >> +#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) >> +#endif >> + >> #endif /* __LINUX_COMPILER_H */ > > You can also remove the #ifdef __CHECKER__ because: > 1) even ancient version of sparse don't have a problem > 2) BUILD_BUG_ON_ZERO() is currently disabled for __CHECKER__ > Nice catch! Will do. Cheers, Miguel