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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BAEFC76196 for ; Tue, 11 Apr 2023 03:50:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229936AbjDKDuH (ORCPT ); Mon, 10 Apr 2023 23:50:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229671AbjDKDuF (ORCPT ); Mon, 10 Apr 2023 23:50:05 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5DE61BFC for ; Mon, 10 Apr 2023 20:50:02 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id e18-20020a17090ac21200b00246952d917fso5150189pjt.4 for ; Mon, 10 Apr 2023 20:50:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1681185002; x=1683777002; h=content-transfer-encoding:in-reply-to:from:references:cc:to:subject :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=CjEAid20/hS5TioSfuhZ2hRVRcGGbWFkXT5AztmUYLU=; b=LYKP57CzAcxQ5gab4YwR9v6vaxhR/4P+GionA8yCWLZ/9hlqmF6jK2Rc7Hkr+pYJ4k VXiDq5ZX5hi4on79vEZq0YxeTPOC7e3+GHpqMEQGRRqjd/zSf+X9k2tX9OYO0Nnc7Uqu 1RusCPGRGIRm768m7eDnzYpfYH4RFQ1dLFZa//rUISjWoXkzVJWR/E6DmSvq+jgunVk0 GlgTAFS9vuG8ltgVdj6Uplw53WEfZZRY9R6/w0AJoTurl+/cvfqFcOH7MZoaiSEGKgsQ unrBv6AgheR1VbEjJIccmEaHodDAELANBNqlpkS6ySpkAEfP43TmwlinKsO/rKzEUpYo a03A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681185002; x=1683777002; h=content-transfer-encoding:in-reply-to:from:references:cc:to:subject :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=CjEAid20/hS5TioSfuhZ2hRVRcGGbWFkXT5AztmUYLU=; b=Kb2ARKeq4d/Mpvok80rV183e9LVQhT0imjJa89TX+SMch6WFtsIglqBNPQOxeqU+OS D7SDZ+Z+nU7u6938AQpsz9LiVOMII8+a0tC78yMENpm2Lvg1M/XwuDQC6EI6WWEbeJ5e scEDODBfjfnCAaBE7RUyjYYcAeW6cTREOOCQ+C9EX6n32dDUEp0vTfk6KSEgU2w+zHf4 39Bc584XNUvYp+mHYD7xpXGP+y+d5baJrlZqfRJMSJ9ztgVVXsGwBBTLSe4yMRqGcdZK 2U5TNqJP6au4u1pOgML8Fz4hEiu1oiDV9cZL+2/gbwN89WqhOs8mBbLrqMFGQJnPfIUc PrSw== X-Gm-Message-State: AAQBX9eHNsDuDZE+JzgogBldx2Am2YSTVt4viTPTWCZ9cbuOJaiL2vGC wnWhDorsFxwIXd7P4dxoWP59qQ== X-Google-Smtp-Source: AKy350YTCKN8pXK1GPOoitNCP80wKJNKIMZKz3O+cK/gOeA1J9898z6qCW9KcqZVIWDDqcWSHJd/hg== X-Received: by 2002:a17:90b:1644:b0:23f:7ff6:eb8 with SMTP id il4-20020a17090b164400b0023f7ff60eb8mr1994829pjb.31.1681185002391; Mon, 10 Apr 2023 20:50:02 -0700 (PDT) Received: from [10.200.10.217] ([139.177.225.248]) by smtp.gmail.com with ESMTPSA id t7-20020a6549c7000000b005136b93f8e9sm7579138pgs.14.2023.04.10.20.49.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 10 Apr 2023 20:50:02 -0700 (PDT) Message-ID: Date: Tue, 11 Apr 2023 11:49:56 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [PATCH v2] maple_tree: Use correct variable type in sizeof To: Matthew Wilcox , Andrew Morton Cc: Peng Zhang , Liam.Howlett@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org, David Binderman , stable@vger.kernel.org References: <20230411023513.15227-1-zhangpeng.00@bytedance.com> <20230410202935.d1abf62f386eefb1efa36ce4@linux-foundation.org> From: Peng Zhang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2023/4/11 11:42, Matthew Wilcox 写道: > On Mon, Apr 10, 2023 at 08:29:35PM -0700, Andrew Morton wrote: >> On Tue, 11 Apr 2023 10:35:13 +0800 Peng Zhang wrote: >> >>> The type of variable pointed to by pivs is unsigned long, but the type >>> used in sizeof is a pointer type. Change it to unsigned long. >> Thanks, but there's nothing in this changelog which explains why a >> -stable backport is being proposed. When fixing a bug, please always >> describe the user-visible effects of that bug. > There is no user-visible effect of this bug as the assembly code > generated will be identical. Therefore, if this has always been the case, cc stable is also unnecessary. > >>> --- a/lib/maple_tree.c >>> +++ b/lib/maple_tree.c >>> @@ -3255,7 +3255,7 @@ static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end >>> >>> if (tmp < max_p) >>> memset(pivs + tmp, 0, >>> - sizeof(unsigned long *) * (max_p - tmp)); >>> + sizeof(unsigned long) * (max_p - tmp)); >>> >>> if (tmp < mt_slots[mt]) >>> memset(slots + tmp, 0, sizeof(void *) * (max_s - tmp)); >> Is there any situation in which >> sizeof(unsigned long *) != sizeof(unsigned long)? > Windows 64-bit (pointer 64-bit, unsigned long is 32 bit) is the only > one I know. Linux is all ILP32 or LP64. There may be some embedded > environments which are different, but I have no idea what they might be. >