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[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 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666785661; a=rsa-sha256; cv=none; b=goRTSnJZ+xq89rrJovCPsBbdPD1ZLIltMBd2PPFZqjeI0meTppDBUs1Rq+IugITym8SjYp Him59Am1iU6whV75PLqLif/Xo4W78wNIYnalYuFAO2APqce2Ul2Kqf4FzgB+QSykKcyi6L HPtrtomFYmJbPRZZbJaPjkHV6F6zRDU= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=ggUvJA2I; spf=pass (imf09.hostedemail.com: domain of lukas.bulwahn@gmail.com designates 209.85.208.52 as permitted sender) smtp.mailfrom=lukas.bulwahn@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666785661; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references:dkim-signature; bh=bbtw+HRW2KLHl7Yg2Uo3gcNX/+9EYg5HCVoRagBLIkA=; b=vU6qKZU6Ko0qH2x9nhXJUggWvabLsRKb22L4phsIjHTUgayNDb9w3Sg2XE8Ej6T5fXhfOM G4c3kD51yVowoQKsrQvTqf2CBvaTxKhqT3QXMS6FY0y1wN6scW8dGpBTo0lnY71YRr9Omd 3vNAiWWDtruMmgczTTyyKQWYOew9r5g= X-Stat-Signature: 99tw6arsuxagbrs7tjya8stszdbqicc9 X-Rspamd-Queue-Id: 6B22F140053 Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=ggUvJA2I; spf=pass (imf09.hostedemail.com: domain of lukas.bulwahn@gmail.com designates 209.85.208.52 as permitted sender) smtp.mailfrom=lukas.bulwahn@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1666785661-955646 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: 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(-)