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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 7BFABC433EF for ; Fri, 10 Sep 2021 11:34:40 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0C8A3611BF for ; Fri, 10 Sep 2021 11:34:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0C8A3611BF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=eldorado.org.br Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:60378 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mOenn-0003Th-26 for qemu-devel@archiver.kernel.org; Fri, 10 Sep 2021 07:34:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48812) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mOeg7-0001z6-I7; Fri, 10 Sep 2021 07:26:43 -0400 Received: from [201.28.113.2] (port=62238 helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mOeg6-0001e6-6q; Fri, 10 Sep 2021 07:26:43 -0400 Received: from power9a ([10.10.71.235]) by outlook.eldorado.org.br with Microsoft SMTPSVC(8.5.9600.16384); Fri, 10 Sep 2021 08:26:37 -0300 Received: from eldorado.org.br (unknown [10.10.70.45]) by power9a (Postfix) with ESMTP id 46035800C19; Fri, 10 Sep 2021 08:26:37 -0300 (-03) From: Luis Pires To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org Subject: [PATCH v3 01/22] host-utils: Fix overflow detection in divu128() Date: Fri, 10 Sep 2021 08:26:03 -0300 Message-Id: <20210910112624.72748-2-luis.pires@eldorado.org.br> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210910112624.72748-1-luis.pires@eldorado.org.br> References: <20210910112624.72748-1-luis.pires@eldorado.org.br> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 10 Sep 2021 11:26:37.0560 (UTC) FILETIME=[B7F74780:01D7A636] X-Host-Lookup-Failed: Reverse DNS lookup failed for 201.28.113.2 (failed) Received-SPF: pass client-ip=201.28.113.2; envelope-from=luis.pires@eldorado.org.br; helo=outlook.eldorado.org.br X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Luis Pires , richard.henderson@linaro.org, groug@kaod.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The previous code didn't detect overflows if the high 64-bit of the dividend were equal to the 64-bit divisor. In that case, 64 bits wouldn't be enough to hold the quotient. Signed-off-by: Luis Pires Reviewed-by: Richard Henderson --- util/host-utils.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/util/host-utils.c b/util/host-utils.c index 7b9322071d..a789a11b46 100644 --- a/util/host-utils.c +++ b/util/host-utils.c @@ -102,7 +102,7 @@ int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor) *plow = dlo / divisor; *phigh = dlo % divisor; return 0; - } else if (dhi > divisor) { + } else if (dhi >= divisor) { return 1; } else { -- 2.25.1