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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 66593C433B4 for ; Fri, 14 May 2021 09:38:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34FC261415 for ; Fri, 14 May 2021 09:38:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231197AbhENJjm (ORCPT ); Fri, 14 May 2021 05:39:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230236AbhENJjl (ORCPT ); Fri, 14 May 2021 05:39:41 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FC63C061574 for ; Fri, 14 May 2021 02:38:28 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id gc22-20020a17090b3116b02901558435aec1so1363818pjb.4 for ; Fri, 14 May 2021 02:38:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=IE6DoBHuj1BTNAGdOQwF+HuP5Ow58xWKxeF4GoigiB8=; b=eIer510lqTQCjTZLmOq26i+2NhOrI1u28jlyH/4DhTSGkvf6fezrqLpfuI1Nza0Xz4 1F24TELAq5p+YfbTifoRKWRvxqh/O5lXJjyXezMaMwIUaC5eBcSxBx8hokSqvPoz55nX y34wWMfY1v0xcVO3cXfrq+8KTlHSWc1BzICtzWSYBsVdIC/JI+RmE8vkH5GRoMieLBeJ IMP23XRt6AQh7nuirgNNTIl4qg+kq23npRB31E/FlxD/pSn8RJB/UG3noCtwXeotlYis NR+8/cJzA3YtFtbv/MT4FhVNQtwNki1hMEkdBu0DQt63qkvGy9iYSq0GYUUP71IWHPKM X30w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IE6DoBHuj1BTNAGdOQwF+HuP5Ow58xWKxeF4GoigiB8=; b=BqscnQxNFYSv5YSIOBt6y0rkgyzX+9qM6o2VfniDklP8xBBOgo2LulkY+3GZSqGcWQ ltN5cxvU6ivIhDb23tm9xaR8Z257QAVWFpFGa6LhYZ+e45OONqc6HnZAh2poVu9i/OTd kxF5V2YnmUgaZrD4UTCMdt8wkBjKmdUSBRH9lBZYNvab3OACe6INAcUgix7yQHgXMBpp JHrr7JJU9KQV8CRz5DMw2cn04rhEX+BwoPhoAcOD1pjUBnHk3LEnPmTdzyjD4goylqoS yZ6Ci4KMTeO8gm04RWFusdPp5J7y9cBMpQa/PaYv02Sj9A+C3UYRiEVpk3A77U2tTFuJ a5rw== X-Gm-Message-State: AOAM533SDQsTFE6vD1MVhizIPGbiPqpmfh1nM2YJVN9XME0blUaVx+wo 7+bgOVyM7lvmh9wbvn0gwbI= X-Google-Smtp-Source: ABdhPJyjp1IWShvMcvIob5BUaLxL4D0Wg399LbwZOqRZPwhzddbzp6Az1oD+r0JKIKgQOu4eWDikyQ== X-Received: by 2002:a17:902:6901:b029:ee:e531:ca5f with SMTP id j1-20020a1709026901b02900eee531ca5fmr45004486plk.37.1620985107198; Fri, 14 May 2021 02:38:27 -0700 (PDT) Received: from yguoaz-VirtualBox.hz.ali.com ([106.11.30.42]) by smtp.googlemail.com with ESMTPSA id w12sm3848421pff.42.2021.05.14.02.38.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 May 2021 02:38:26 -0700 (PDT) From: Yiyuan GUO X-Google-Original-From: Yiyuan GUO To: hare@suse.de Cc: axboe@kernel.dk, linux-block@vger.kernel.org, yguoaz@cse.ust.hk, yguoaz@gmail.com Subject: [PATCH v2] block: add protection for divide by zero in blk_mq_map_queues Date: Fri, 14 May 2021 17:38:16 +0800 Message-Id: <20210514093816.66612-1-yguoaz@cse.ust.hk> X-Mailer: git-send-email 2.25.1 In-Reply-To: <274501fd-3115-3015-3577-3ed64e4038a0@suse.de> References: <274501fd-3115-3015-3577-3ed64e4038a0@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org In function blk_mq_map_queues, qmap->nr_queues may equal zero and thus it needs to be checked before we pass it to function queue_index. Signed-off-by: Yiyuan GUO --- block/blk-mq-cpumap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index 3db84d319..c2163658e 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -64,7 +64,7 @@ int blk_mq_map_queues(struct blk_mq_queue_map *qmap) map[cpu] = queue_index(qmap, nr_queues, q++); } else { first_sibling = get_first_sibling(cpu); - if (first_sibling == cpu) + if ((first_sibling == cpu) && nr_queues) map[cpu] = queue_index(qmap, nr_queues, q++); else map[cpu] = map[first_sibling]; -- 2.25.1