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 55EF1ECDFA1 for ; Wed, 26 Oct 2022 12:01:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233536AbiJZMBH (ORCPT ); Wed, 26 Oct 2022 08:01:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231476AbiJZMBE (ORCPT ); Wed, 26 Oct 2022 08:01:04 -0400 Received: from mail-ed1-x529.google.com (mail-ed1-x529.google.com [IPv6:2a00:1450:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8445762900; Wed, 26 Oct 2022 05:01:01 -0700 (PDT) Received: by mail-ed1-x529.google.com with SMTP id z97so41005332ede.8; Wed, 26 Oct 2022 05:01:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=bbtw+HRW2KLHl7Yg2Uo3gcNX/+9EYg5HCVoRagBLIkA=; b=ggUvJA2IjkkFVR7NAfRcitqbXwBiJfMYPc/6Rxg3BC0XsP6r3isgE7h6ThIPiNlA4o npPZMMp2U21fkqhALp56gPM2IEy7LfNkT/0Ir+tKimHwUuQiHMbfwG5za/rZ/WWujXIz zyqTmgTYVutFLxLcrwYLC1/W4qVAJgXVlHQMWORqIqfDWNvagTGJab0wLIw7UVWN9InC Zk6AAdIl/OdX7LRG8h+0HKi+BDtCJrstz6Kq58RrL6GbpOT6wZNG43JF/1BGpUmjD8ga LMNZoJWlxjgWumaLkui3hBf4nXI+9Eev35RDpkFI0JgfFIvhFGm7R/qj4XOdybFWYsUZ k6Kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bbtw+HRW2KLHl7Yg2Uo3gcNX/+9EYg5HCVoRagBLIkA=; b=LWSYdvUT1kYfaMZqJRbxDq63SNqWKygyNCo5HIMEeIkCcwIk8kkMd9ujlaSWbDLZyo M3l/4ThkxeowXj4W9k4/vBkFvFw8RFAyWn9Ij5zNbv7FvL59ax5Fb9cQJTOhvW4GefEZ rEqsiafHV1lmXglbzeKuIpYCmmku/8StkrQKO0bJhUvXFkV4iBamA6f7WVrOrTDiuDxo wZqxJgxSgMXJWIGTpeapeAH1soLsL5SBXOT7h0Wb/z/4+jOdXPi97xl9TxtMd5/KBqz1 PjgvGAkStVXcFXV/EHA8wK7FhA5mhUT64/m7EfzCq2U7I/jegAIuBGwzzMo4K6sp+g2E wucQ== X-Gm-Message-State: ACrzQf0r4RsgYEgDq4pp5H/HkpMI/gDW2aaAOmmJthvJL4vJqXNEn8mE zrDWCab1hjcPONrFdZ+unrw= X-Google-Smtp-Source: AMsMyM6cjz1cxDXxmcXl52+FSt5RnzvM6WTi/mlDsR93q4wrCLyCkB+KHz+hkJutaz5jUk7+0BAdmQ== X-Received: by 2002:aa7:dc10:0:b0:440:b446:c0cc with SMTP id b16-20020aa7dc10000000b00440b446c0ccmr40232509edu.34.1666785659926; Wed, 26 Oct 2022 05:00:59 -0700 (PDT) Received: from felia.fritz.box (200116b826195000091b3ab8e8f9a156.dip.versatel-1u1.de. [2001:16b8:2619:5000:91b:3ab8:e8f9:a156]) by smtp.gmail.com with ESMTPSA id ky21-20020a170907779500b00788c622fa2csm2872760ejc.135.2022.10.26.05.00.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Oct 2022 05:00:58 -0700 (PDT) From: Lukas Bulwahn To: "Liam R . Howlett" , Matthew Wilcox , Andrew Morton , linux-mm@kvack.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, Lukas Bulwahn Subject: [PATCH 0/1] Dead stores in maple-tree Date: Wed, 26 Oct 2022 14:00:28 +0200 Message-Id: <20221026120029.12555-1-lukas.bulwahn@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dear maple-tree authors, dear Liam, dear Matthew, there are some Dead Stores that clang-analyzer reports: lib/maple_tree.c:2906:2: warning: Value stored to 'last' is never read [clang-analyzer-deadcode.DeadStores] lib/maple_tree.c:2907:2: warning: Value stored to 'prev_min' is never read [clang-analyzer-deadcode.DeadStores] I addressed these two cases, which were most obvious and clear to fix; see patch of this one-element series. Further, clang-analyzer reports more, which I did not address: lib/maple_tree.c:332:2: warning: Value stored to 'node' is never read [clang-analyzer-deadcode.DeadStores] lib/maple_tree.c:337:2: warning: Value stored to 'node' is never read [clang-analyzer-deadcode.DeadStores] Unclear to me if the tool is wrong or right in its analysis here for the two functions above. lib/maple_tree.c:1212:23: warning: Value stored to 'nodep' during its initialization is never read [clang-analyzer-deadcode.DeadStores] A lot of pointer magic. Unclear to me if the tool is wrong or right in its analysis here. lib/maple_tree.c:5014:5: warning: Value stored to 'count' is never read [clang-analyzer-deadcode.DeadStores] Unclear if the code is intended as it is now. In mas_anode_descend(), the variable count is really just assigned and used once effectively. The second assignment is never read. So, the variable count could just be removed in mas_anode_descend(). Maybe these further warnings are helpful to clean up the code or find an issue that was overlooked so far. Best regards, Lukas Lukas Bulwahn (1): lib: maple_tree: remove unneeded initialization in mtree_range_walk() lib/maple_tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.17.1