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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EDAAEC4727C for ; Tue, 29 Sep 2020 20:13:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D8542076A for ; Tue, 29 Sep 2020 20:13:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BIudEvYy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728362AbgI2UN2 (ORCPT ); Tue, 29 Sep 2020 16:13:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725372AbgI2UN2 (ORCPT ); Tue, 29 Sep 2020 16:13:28 -0400 Received: from mail-qv1-xf42.google.com (mail-qv1-xf42.google.com [IPv6:2607:f8b0:4864:20::f42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC411C061755; Tue, 29 Sep 2020 13:13:27 -0700 (PDT) Received: by mail-qv1-xf42.google.com with SMTP id f11so2981060qvw.3; Tue, 29 Sep 2020 13:13:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=2yE8tLnNFogNu2DcQZ3zwF/fyfjhAGFtUaRsrh9630g=; b=BIudEvYyd7e1T8YFoEmamwmrXDhkLwQJxr4BDM05kapleUxs0tthYqNKmZe2im7Fg4 hqZobpyIYcoNoi3aCrfE9xsIeVuG/nvtg60WkfSsIhiRxHrauZ3/kmFbm8zve6GAcLRe NfPPDG/F5nIBaBWcpAoNs9Jaj8p9OChDC+IfpR4TL4tn+jumhOdG7+L1+xhuEToq/p4I 1c83r3GUGkjfpccGMNvxMABHMlq11fnH7DTbqKu69VJYdr9qG7GPD4PBLoIwQsmBOzav 2SleYCY84l6fOPHP/XSRrHvvp4HhF0vSRGfPia6ybKVH5Cu9JEWVe/Bs1a6UmF6+EWmt zg5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=2yE8tLnNFogNu2DcQZ3zwF/fyfjhAGFtUaRsrh9630g=; b=FJ9IbHRFnmVtzZ3XKotQok3lGZCG+hiA0tHcASWFGYtpT2ucOot6d3IcgLnNkWeY5E ea3NUOQjgluFfd72AThUBtM5+lXVIrBeAJo34e1/0GKeIJzX3z4ADAa0bnvWz4HnZGcI NS7N7clIkiRXfKtLpMKo2Fl5picCyhk3cFD2LOtRNEMNAlZiU02IumUtPrnOzRTAKn52 TqPO89Zg5Kxc6QIS87e3fKAOgjd+s7l3Wd0WLYVHS09Hgf5PQfHmLD2aadCTQCRPFHIn czDIcvihkc2IBgWUIfWkCKLDUhSUfBuPbytMdJm54hBbVMvpqWMKUPIt7tPfimrSB+Gf hN9Q== X-Gm-Message-State: AOAM5309gBiKzCrSabdzbICOGeVx7EZgmvJ+p1/1+FFEi72B/MuBNc1C HyXFMoNn+O+txfx60IIqxotFrOz9XxoQFA== X-Google-Smtp-Source: ABdhPJyzo/sh8biAN7ip8oRKWAQiwRLTYpJG2Fyd/mCxZt16Q4VCaIYRuBYqFS+C0odiRwqn2364UA== X-Received: by 2002:a0c:d443:: with SMTP id r3mr6364147qvh.17.1601410406562; Tue, 29 Sep 2020 13:13:26 -0700 (PDT) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id c40sm7012393qtb.72.2020.09.29.13.13.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Sep 2020 13:13:26 -0700 (PDT) Sender: Arvind Sankar From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Tue, 29 Sep 2020 16:13:24 -0400 To: Arvind Sankar Cc: Nick Desaulniers , Andrew Morton , Miguel Ojeda , Luc Van Oostenryck , Nathan Chancellor , linux-sparse@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH] compiler.h: avoid escaped section names Message-ID: <20200929201324.GB2668747@rani.riverdale.lan> References: <20200929194318.548707-1-ndesaulniers@google.com> <20200929200801.GA2668747@rani.riverdale.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200929200801.GA2668747@rani.riverdale.lan> Precedence: bulk List-ID: X-Mailing-List: linux-sparse@vger.kernel.org On Tue, Sep 29, 2020 at 04:08:01PM -0400, Arvind Sankar wrote: > On Tue, Sep 29, 2020 at 12:43:18PM -0700, Nick Desaulniers wrote: > > The stringification operator, `#`, in the preprocessor escapes strings. > > For example, `# "foo"` becomes `"\"foo\""`. GCC and Clang differ in how > > they treat section names that contain \". > > > > The portable solution is to not use a string literal with the > > preprocessor stringification operator. > > > > In this case, since __section unconditionally uses the stringification > > operator, we actually want the more verbose > > __attribute__((__section__())). > > > > Link: https://bugs.llvm.org/show_bug.cgi?id=42950 > > Fixes: commit e04462fb82f8 ("Compiler Attributes: remove uses of __attribute__ from compiler.h") > > Signed-off-by: Nick Desaulniers > > --- > > include/linux/compiler.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/linux/compiler.h b/include/linux/compiler.h > > index 92ef163a7479..ac45f6d40d39 100644 > > --- a/include/linux/compiler.h > > +++ b/include/linux/compiler.h > > @@ -155,7 +155,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, > > extern typeof(sym) sym; \ > > static const unsigned long __kentry_##sym \ > > __used \ > > - __section("___kentry" "+" #sym ) \ > > + __attribute__((__section__("___kentry+" #sym))) \ > > = (unsigned long)&sym; > > #endif > > > > -- > > 2.28.0.709.gb0816b6eb0-goog > > > > There was this previous mini-thread: > https://lore.kernel.org/lkml/20200629205448.GA1474367@rani.riverdale.lan/ > and this older one: > https://lore.kernel.org/lkml/20190904181740.GA19688@gmail.com/ > > Just for my own curiosity: how does KENTRY actually get used? grep > doesn't show any hits, and the thread from 2019 was actually going to > drop it if I read it right, and also just remove stringification from > the __section macro. > > There are still other instances that need to be fixed, right? > > Thanks. Ignore the last question, I see you have separate patches for the rest.