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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 A0296C433ED for ; Tue, 18 May 2021 20:30:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4E3AC6135B for ; Tue, 18 May 2021 20:30:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4E3AC6135B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E26B28E0051; Tue, 18 May 2021 16:30:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DD6FB8E002F; Tue, 18 May 2021 16:30:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C50948E0051; Tue, 18 May 2021 16:30:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0092.hostedemail.com [216.40.44.92]) by kanga.kvack.org (Postfix) with ESMTP id 8EB658E002F for ; Tue, 18 May 2021 16:30:18 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 342A9181AF5F7 for ; Tue, 18 May 2021 20:30:18 +0000 (UTC) X-FDA: 78155494116.25.AF22C71 Received: from mail-lj1-f175.google.com (mail-lj1-f175.google.com [209.85.208.175]) by imf20.hostedemail.com (Postfix) with ESMTP id AA1B53C6 for ; Tue, 18 May 2021 20:30:17 +0000 (UTC) Received: by mail-lj1-f175.google.com with SMTP id f12so13038146ljp.2 for ; Tue, 18 May 2021 13:30:17 -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=4Bk9uyRl39i9BigbgL1GtEM49Gq25V6Tx/nXtBMrKNo=; b=mofCgvJkkGJgUFrowNr047mWFYLqxlNiPdenhhnYFLtrf3IQ1CZd62y5f8HADruKDR ErriEpbaLgEc+vbv9t1OkBEd0PWXDL6hKOemqw9kCuk+3/aaQaxkzae6Gox9rUrIjhVi 2f0kkpjbrxoMJljbtRUGtN8kjFneN79IqB8AS/Q2Ig8VCzacCU/+RU6KswmZi6PyiHx/ xNfmQdsDP4EFnkO2HfDCRycrUn+S3MkOiIoPrFbu9nkhf3FsS9vfyK06XScgBL0DjAXn GRr+1RHdh0eWPRDUfOpA8Jh1dE7XpcacP5wG8FqQcOEjWLl3dQS68dqp1R/8Zc36ZRXX ICmA== 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=4Bk9uyRl39i9BigbgL1GtEM49Gq25V6Tx/nXtBMrKNo=; b=ZgBLPLJAAbH6dr5zevLdMBklcFFccAQsI2GwRCP91fLyerYkze2niHJ2JjteYuzmr1 Ks9fgtaGdWuYMgWVK7KcDrhJBp2EYm8gmnjdjQ8N7mtoqj2mH8zPwXoHsEANuNfPjNF6 SoHqA7YCC5MBVvrMeZ2oA0uDLBs/Z3b+yuDp0FprzwVJVEt4YEX3hHhgQbdTlxu8QuRJ AX86cQvYMhJKqTfEsiGoeNHBcnKPllomIkC+ppRlToUY/TwZWpfZVtEh6BuVHMfd/0oF 4MEoCvqQ9caNDAPjjVLebVzwH3GH1X+p2IWLW95SLo1SBZb6k2wKbwAKN1b1BAcVEBnj 3Tug== X-Gm-Message-State: AOAM532x+ma84j0SkmS00zO5HaeTCvYiQHMSqmJqYce0lvPyTgv5wrwD Dc09Pbf2yZm/ORm/8BHK8huANG4Xk1B4R8QzyKqfNQ== X-Google-Smtp-Source: ABdhPJxkfBJNSq22wsmPPI5Rlho3AJN6nyLxBn81iDJNAa2KAlRw1b95RKfh5eHdEPzg2SwiL/2djVUmAg+MuMugAjE= X-Received: by 2002:a05:651c:106f:: with SMTP id y15mr1811072ljm.244.1621369816059; Tue, 18 May 2021 13:30:16 -0700 (PDT) MIME-Version: 1.0 References: <20210518181247.GA10062@hyeyoo> In-Reply-To: <20210518181247.GA10062@hyeyoo> From: Nick Desaulniers Date: Tue, 18 May 2021 13:30:05 -0700 Message-ID: Subject: Re: [PATCH] mm, slub: Fix support for clang 10 To: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Nathan Chancellor , Stephen Rothwell , Linux Memory Management List , LKML , clang-built-linux , Naresh Kamboju Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: AA1B53C6 Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=google.com header.s=20161025 header.b=mofCgvJk; spf=pass (imf20.hostedemail.com: domain of ndesaulniers@google.com designates 209.85.208.175 as permitted sender) smtp.mailfrom=ndesaulniers@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam04 X-Stat-Signature: qrbzezmcoa5tffxti8etfq5m8dcf68hu X-HE-Tag: 1621369817-406957 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, May 18, 2021 at 11:12 AM Hyeonggon Yoo <42.hyeyoo@gmail.com> wrote: > > Previously in 'commit ff3daafe3fd3 ("mm, slub: change run-time assertion > in kmalloc_index() to compile-time")', changed kmalloc_index's run-time > assertion to compile-time assertion. > > But clang 10 has a bug misevaluating __builtin_constant_p() as true, > making it unable to compile. This bug was fixed in clang 11. > > To support clang 10, introduce a macro to do run-time assertion if clang > version is less than 11, even if the size is constant. Might revert this > commit later if we choose not to support clang 10. > > Fixes: ff3daafe3fd3 ("mm, slub: change run-time assertion in kmalloc_index() to compile-time") > Link: https://lore.kernel.org/r/CA+G9fYvYxqVhUTkertjZjcrUq8LWPnO7qC==Wum3gYCwWF9D6Q@mail.gmail.com/ > Link: https://lkml.org/lkml/2021/5/11/872 > Reported-by: Naresh Kamboju > Suggested-by: Nathan Chancellor > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Thanks for the patch; hopefully this isn't too much burden in order to help us support clang-10 a little bit longer. We will rip it out when dropping clang-10 someday; grepping for CLANG_VERSION should turn this up easily. Reviewed-by: Nick Desaulniers > --- > include/linux/slab.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/slab.h b/include/linux/slab.h > index 9d316aac0aba..8d8dd8571261 100644 > --- a/include/linux/slab.h > +++ b/include/linux/slab.h > @@ -413,7 +413,7 @@ static __always_inline unsigned int __kmalloc_index(size_t size, > if (size <= 16 * 1024 * 1024) return 24; > if (size <= 32 * 1024 * 1024) return 25; > > - if (size_is_constant) > + if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 110000) && size_is_constant) > BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); > else > BUG(); > -- > 2.25.1 > -- Thanks, ~Nick Desaulniers