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 9FAAEC4321E for ; Mon, 28 Nov 2022 19:58:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233989AbiK1T6f (ORCPT ); Mon, 28 Nov 2022 14:58:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233957AbiK1T61 (ORCPT ); Mon, 28 Nov 2022 14:58:27 -0500 Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E63302DABA; Mon, 28 Nov 2022 11:58:21 -0800 (PST) Received: by mail-pg1-x531.google.com with SMTP id 6so10902435pgm.6; Mon, 28 Nov 2022 11:58:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=fW5pu/oGfiEsFMKGLZAHU+S02fDyBuhcJUqWHINL2qU=; b=mx86HuOzrzmHVFcBmkCrHteGNzM0udqe/N2eUm6fMH2MBbX1t4PmdhNn+tBat/L0ad cBZ+zD49RA1+ZK+Cc9Uph5opYzkQ0i4yGNCB/ET7oI9hRX3+qg2Zf7XLlemLJvGlt01z FAjBLe2U/tvLvC4pYTUMQSJf577RdcisPSatY6/7pfOuoVkQDFlwGvZcQEYeI+3Ex+Lv 4qfGpvfTGHFCwuxsHQnbIm59Vq4YUuqQk/qWfk/C4OGA2oBCvAXFioZGj+sHUIHAOQRE sjslj73JFVvORreDotKaFGVo1vdffNYJEChWtP+VpUyKv5z4aG0vVzeuUQMrY9qZHaVQ lW9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=fW5pu/oGfiEsFMKGLZAHU+S02fDyBuhcJUqWHINL2qU=; b=l0OyAo2Liy58Ipl9LL+3vih9mM0AqME2fLZMd50NfB+RdBP4z1Hg53DRqSt0kmLHtR 8EJAe3LBMAiwIIEw47VFvFxvN2cZ7PS2y7RwZ6omIXn4i8aufPEcn+2fD7EK41jIJTYF uGEKE1AihP5UTCY4VAUrEZfF7CtTxH8vHsWKo/TMVfTCG0W7DHd01iZ5g9G9qB5Ba7Ui OT+TQj5z2TMCQivzlfIk8/14UwrZE7Wn7krQ+ot7uEOL25ZsF0tfBkNSNbGBlUl76yGC gcg7rv1uzC5ct1sNFDzgmxOzI38iH23g11umJEjZ0nmBqiiCuxWgwNlOC4lpSU98K69N OvIQ== X-Gm-Message-State: ANoB5pljcWSvyAs0nv8SS0eV2P3ww0HxGwbsCOPpWmFmkvhpfFZcHSU4 GinJl79YwyJeTMi8RXdGqZQ= X-Google-Smtp-Source: AA0mqf4+3eTeelHiOphx4mGFDAToBKPFZ+PiffRH9fKb3FklhereSaV0NjfaAn5L56A5Bxv4pP/Bjw== X-Received: by 2002:a05:6a00:410b:b0:56d:91d1:a903 with SMTP id bu11-20020a056a00410b00b0056d91d1a903mr34175954pfb.61.1669665500411; Mon, 28 Nov 2022 11:58:20 -0800 (PST) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id u11-20020a170902bf4b00b0017f7c4e260fsm9278717pls.150.2022.11.28.11.58.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Nov 2022 11:58:20 -0800 (PST) Sender: Tejun Heo Date: Mon, 28 Nov 2022 09:58:18 -1000 From: Tejun Heo To: Li Jinlin Cc: josef@toxicpanda.com, axboe@kernel.dk, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, liuzhiqiang26@huawei.com Subject: Re: [PATCH v2] blk-iocost: fix shift-out-of-bounds in iocg_hick_delay() Message-ID: References: <20221128030413.882998-1-lijinlin3@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221128030413.882998-1-lijinlin3@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Nov 28, 2022 at 11:04:13AM +0800, Li Jinlin wrote: > /* calculate the current delay in effect - 1/2 every second */ > tdelta = now->now - iocg->delay_at; > if (iocg->delay) > - delay = iocg->delay >> div64_u64(tdelta, USEC_PER_SEC); > + delay = iocg->delay >> > + min_t(u64, div64_u64(tdelta, USEC_PER_SEC), 63); I replied earlier but the right thing to do here is setting delay to 0 if the shift is >= 64. Thanks. -- tejun