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 88B46C433EF for ; Mon, 20 Jun 2022 11:24:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241341AbiFTLYI (ORCPT ); Mon, 20 Jun 2022 07:24:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229910AbiFTLYG (ORCPT ); Mon, 20 Jun 2022 07:24:06 -0400 Received: from mail-lj1-x22a.google.com (mail-lj1-x22a.google.com [IPv6:2a00:1450:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1C2715830 for ; Mon, 20 Jun 2022 04:24:05 -0700 (PDT) Received: by mail-lj1-x22a.google.com with SMTP id v8so11533512ljj.8 for ; Mon, 20 Jun 2022 04:24:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6Yt7N7lIt6rrL+t7Ro4DPilPiH3bCntuNreRubvS7Kc=; b=P86niLyEltitD6qcrewvCIeD/Op6qsjJFYmoGU6u+gtc6fVIqmPbQhGFZEkDLgI6OI BXArQyWCEe/Cyz8l5OJ3nYOh+qih2Kxxycb2IrB1x91kOt1hBtAcm8Ms7plCV9r3Sw02 BDdJBwuF5+ZhxP8OIygE9OSGlfvj1YA8GBERqjBNiHmTHtPc002LYYI/WdFffSmVbFp7 ss5zm6nJOmHMP5dnB8lYHWM97VavfT7DzMnxXQ6bP5emyjiGDGqPvQkfKWXHTzLppgpl vmz0e+IzsOKiUPE8lJjv/rRI2sxRvUDpLWNXXZ00Tvx0CTMU593HWGFbs/WjimSaAeo7 98BA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6Yt7N7lIt6rrL+t7Ro4DPilPiH3bCntuNreRubvS7Kc=; b=3ZxDXQ92oDJaMzNGhzwoQPbYH07zLk6GtwDWlzjZH3HS9Dyd/M34SvHg5XAID+ClNj PWXCH+ircUsuxlXtoXWIWAlW0Vj+etNqJVLaXzYH8C9vK4Y952jyKz6y2EJVqGAfcRPZ KVVEFIOyAOrrvcH08EJd6VFGFeVuMlIikNkyHq835QOF4NFCnu/LxPIG8EnOOrvYmYSb Z+A34toZnbQ7cei6n20YQHnCbc5OMweYV76C21ov7utcKTOM5Rf9ZrMCKg61lH0cXTWP EIqFyDDJsJ5FaWFxUpNxFJzOWnhdJZjvp7nRs97mVAxbrEezfifXhMOVNj8JCGTNX5Nr oBtw== X-Gm-Message-State: AJIora9AwTQagzrnrfTOHjsFfjIdkftQDaV4Q21Vu9UWXnM50h0T8Vaw EZ5Mv/VVt0BGHc2lk+3G/jEIyQlXnx1kmhmHZIA= X-Google-Smtp-Source: AGRyM1tkovQ3GhgpyWicWNL/SBpHcmpj4RpsJcHMRz54/hlnlFAbPCTQ0AcppAB5v0FJLJ4PjVP8MQEzCRBA39J1FiI= X-Received: by 2002:a2e:7d17:0:b0:25a:6ccd:ab6 with SMTP id y23-20020a2e7d17000000b0025a6ccd0ab6mr3048176ljc.114.1655724244209; Mon, 20 Jun 2022 04:24:04 -0700 (PDT) MIME-Version: 1.0 References: <1653447164-15017-1-git-send-email-zhaoyang.huang@unisoc.com> In-Reply-To: From: Zhaoyang Huang Date: Mon, 20 Jun 2022 19:23:34 +0800 Message-ID: Subject: Re: [PATCH] mm: fix racing of vb->va when kasan enabled To: Uladzislau Rezki Cc: "zhaoyang.huang" , Andrew Morton , "open list:MEMORY MANAGEMENT" , LKML , Ke Wang , Christoph Hellwig Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 20, 2022 at 6:44 PM Uladzislau Rezki wrote: > > > > > > > > Is it easy to reproduce? If so could you please describe the steps? As i see > > > the freeing of the "vb" is RCU safe whereas vb->va is not. But from the first > > > glance i do not see how it can accessed twice. Hm.. > > It was raised from a monkey test on A13_k515 system and got 1/20 pcs > > failed. IMO, vb->va which out of vmap_purge_lock protection could race > > with a concurrent ra freeing within __purge_vmap_area_lazy. > > > Do you have exact steps how you run "monkey" test? There are about 30+ kos inserted during startup which could be a specific criteria for reproduction. Do you have doubts about the test result or the solution? > > -- > Uladzislau Rezki