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=-13.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,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 9DE09C43331 for ; Thu, 5 Sep 2019 17:18:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F44D20828 for ; Thu, 5 Sep 2019 17:18:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GdxnRRAn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388111AbfIERSy (ORCPT ); Thu, 5 Sep 2019 13:18:54 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:41194 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730704AbfIERSy (ORCPT ); Thu, 5 Sep 2019 13:18:54 -0400 Received: by mail-pg1-f195.google.com with SMTP id x15so1761488pgg.8 for ; Thu, 05 Sep 2019 10:18:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=i6E/jdqx5yvxD+dBch8iFfgicvMUor5p5VuDHpWaSQk=; b=GdxnRRAnkzCqpPGZ4tyRiPeYXpZcyBfZHxASg8zQRPiBPXXddkT8OGJxFjAqMyDNNc HrGFU9VxZ9ep7pvA7IpCXg4EHA9E+6tXZWE5JBC3EHerejM0l21AYcnpWrMuM3fzz4m1 TA/Fj7aANMHURAUZNIVWxAaTH1Mru+0ySGoMKOLKXc5puzP2KAqG8J/Ju4KJYgD0uuIA XiFwgqr7QtisHePYLZeKcynhpomQT55ND4q9agYPzJM4gqGBRRGiCWF9oo/iz1O1IGjY Q/QHy/EM5gCE1mEB3CQYtqQ5+EKr3NdfL6JuiHat11C0t7WuQMKhq0/K6IMKIOn7Bzl8 KqSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=i6E/jdqx5yvxD+dBch8iFfgicvMUor5p5VuDHpWaSQk=; b=Vz+NNdJG/YN1Xf+7KOAJOCj0uTsRmH7R5kKtHoO5l4ALMgF5ClfGeacUHoZidctNp5 B19LDxgqJjNRLaURK9l3wn1ZreGN0H7VNM7VPRYF2i8+FaCkFbQ030/HOYmH7ObA+cY5 190ysTh3dgQNPtH5FqLxbsjuVvE0uzss4w+J5qLw3+AFLkoUQBq7ofZpkDNLYc8VpqVI pbvDiEBhABkj0Ku8TUJGquYTSuKvMtLP/jhnOgjtYO4+byw4P0xD9YYDN9MmfFFjROf1 KU0GPl59K+J2YCXVSJYj4mZywZVmkBRszzbomCu/smsd3PxEDE4VL9AewOM+rW1KqfDY zmsw== X-Gm-Message-State: APjAAAWh0FsGmriSEbeHnd4JyYBIIw1lZEVl4d8NHT5xGxUA9HiEZ1C7 Ci3tEfQ+b6Cn+W5RPpaTh+3Cba9Z7ey0wwU414Ce2g== X-Google-Smtp-Source: APXvYqz+TwqquVyjr+UJa4p3V/xCVWf0lJ/UQlbjEbCSUDis/OUAVFrXmjExz+xckpV+hl5YShcuAFjuUrx9vdwy7Ps= X-Received: by 2002:a62:cec4:: with SMTP id y187mr5205861pfg.84.1567703932781; Thu, 05 Sep 2019 10:18:52 -0700 (PDT) MIME-Version: 1.0 References: <20190904181740.GA19688@gmail.com> In-Reply-To: From: Nick Desaulniers Date: Thu, 5 Sep 2019 10:18:41 -0700 Message-ID: Subject: Re: [GIT PULL] compiler-attributes for v5.3-rc8 To: Linus Torvalds Cc: Miguel Ojeda , Will Deacon , Josh Poimboeuf , "Naveen N. Rao" , "David S. Miller" , Paul Burton , Sedat Dilek , Linux List Kernel Mailing 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 On Thu, Sep 5, 2019 at 9:20 AM Linus Torvalds wrote: > > On Wed, Sep 4, 2019 at 11:18 AM Miguel Ojeda > wrote: > > > > I was going to send this for 5.4 since it is not that trivial, but since > > you are doing an -rc8, and it fixes an oops, please consider pulling it. > > I looked at this, and while it seems safe, I end up worrying. > > Macro stringification isn't entirely obvious, and an unquoted string > could become corrupted if the stringification ends up not happening > immediately. > > It does seem safe just because we do > > #define __section(S) __attribute__((__section__(#S))) > > but I had to go _check_ that we do, because it wouldn't have been safe > if there had been another level of macro expansion, because then the > argument in turn could have been expanded before it was stringified. > > So sometimes you actually _want_ to pass in a string to be > stringified, because it's safer. I realize it then gets string-quoted, > but this has worked for gcc. Even if I suspect nobody really _thought_ > about it. > > So I'm not unhappy about the patch, but it's the kind of thing I'd > really prefer not to do at this stage. > > Particularly since it seems to do other things too than just fix > double quoting. As far as I can tell, it doesn't just fix double > string quoting, it changes a lot of singly-quoted strings to use the > macro and unquotes them, ie > > - __attribute__((__section__(".arch.info.init"))) = { \ > + __section(.arch.info.init) = { \ > > doesn't actually "fix" anything that I can see, it just uses the simpler form. Please consider picking up just: https://github.com/ojeda/linux/commit/c97e82b97f4bba00304905fe7965f923abd2d755 That lone patch is the one that fixes the particularly observed Oops. The rest are just cleanup; if I made that change in the more important patch, why not clean up the rest of the instances in the kernel? -- Thanks, ~Nick Desaulniers