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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 34CEFCA9EB9 for ; Tue, 22 Oct 2019 14:56:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 099F6218AE for ; Tue, 22 Oct 2019 14:56:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ToZRFpOB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732116AbfJVO4Y (ORCPT ); Tue, 22 Oct 2019 10:56:24 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:42394 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727582AbfJVO4Y (ORCPT ); Tue, 22 Oct 2019 10:56:24 -0400 Received: by mail-lf1-f65.google.com with SMTP id z12so13362339lfj.9 for ; Tue, 22 Oct 2019 07:56:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=3YSqKTmEXvv06IcTKWhjuHPCxpqgXAh/q72UPZZW4tI=; b=ToZRFpOBn0qIY8fB8zR8Lx8J0SvcEBPHS4Ke6VL6ZNhhL/LtWoi/+mYzcFM3AZ5F/k JJzm4gf1qJGWc7fZXjLx51SqFCGNVr11Fld+rCJdJPiaiv9K9+H/Awar60IklzsClPsp H1PSx72g1cmbVfm2POFgj6DCDSFyghyfZpSDcipX899l1cxx4E0yN/3U3/fEmCg6cnKv KP2GQ5YIbCBSK6mm+8PA0X4ueFZ9cFYdObU+ifCicSirGxhAEPpKYLQE4nz+qkWhZm+K d0edEPJEaIAQIU4BGyhDrJO/riuzWEbjkalzzjIoxMhegedxSKSgPlwzOfdyjEAXmGDO Dd7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=3YSqKTmEXvv06IcTKWhjuHPCxpqgXAh/q72UPZZW4tI=; b=rPe/kGLmZhENgRZNp2EjbRZC3SuOvMsUCm913hPz2o2G5KTMJsnWfc5gAxbaB3U9je S1ku9WAqMiuLT8VSThLr4MDeMj88LJbDN39mjM0z5BgXyhoWOmK29/DVv9uz23NQA9D8 ThUcU/HIlMFEfKR7gbNGEZj96EbDvWfrKkhSxRsAAPtLfTeW0bSBaqw5Y8BlhgMt6tVP SKEqnGR7CmdEt8/gZmj6Qu0sOFpcl5Iqeyw+ZQDu+IOFJkgOvFfIVim/z80Uts0qSVl9 n7gDtQ3625JgPoVPWIuQYJYL4Pu08xMus42xW3KJR2k0eEtZjEl/WWvLX4wD0q//MPIp c3+A== X-Gm-Message-State: APjAAAVDxM2838T5BX4Wq+CapBezCk4WTWRNvdKvyyfIPoApK5/RXEMG 9e8rdWz8ZAPtENUbsbSyJRw= X-Google-Smtp-Source: APXvYqzT+WvhUfV1dqaHP8e3bPnI7W7wtrekNZPYhPERXxqxvTDLLjx7cLMOG0+GgVTNcByTEFv+uw== X-Received: by 2002:ac2:47ed:: with SMTP id b13mr15065139lfp.43.1571756182359; Tue, 22 Oct 2019 07:56:22 -0700 (PDT) Received: from uranus.localdomain ([5.18.199.94]) by smtp.gmail.com with ESMTPSA id k8sm9185096ljg.9.2019.10.22.07.56.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Oct 2019 07:56:21 -0700 (PDT) Received: by uranus.localdomain (Postfix, from userid 1000) id EAF9B460E3F; Tue, 22 Oct 2019 17:56:19 +0300 (MSK) Date: Tue, 22 Oct 2019 17:56:19 +0300 From: Cyrill Gorcunov To: LKML Cc: Ingo Molnar , Thomas Gleixner , Peter Zijlstra , linux-mm@kvack.org, Catalin Marinas Subject: Re: [BUG -tip] kmemleak and stacktrace cause page faul Message-ID: <20191022145619.GE12121@uranus.lan> References: <20191019114421.GK9698@uranus.lan> <20191022142325.GD12121@uranus.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191022142325.GD12121@uranus.lan> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 22, 2019 at 05:23:25PM +0300, Cyrill Gorcunov wrote: > > I presume the kmemleak tries to save stack trace too early when estack_pages are not > yet filled. Indeed, at this stage of boot the percpu_setup_exception_stacks has not been called yet and estack_pages full of crap [ 0.157502] stk 0x1008 k 1 begin 0x0 end 0xd000 estack_pages 0xffffffff82014880 ep 0xffffffff82014888 [ 0.159395] estack_pages[0] = 0x0 [ 0.160046] estack_pages[1] = 0x5100000001000 [ 0.160881] estack_pages[2] = 0x0 [ 0.161530] estack_pages[3] = 0x6100000003000 [ 0.162343] estack_pages[4] = 0x0 [ 0.162962] estack_pages[5] = 0x0 [ 0.163523] estack_pages[6] = 0x0 [ 0.164065] estack_pages[7] = 0x8100000007000 [ 0.164978] estack_pages[8] = 0x0 [ 0.165624] estack_pages[9] = 0x9100000009000 [ 0.166448] estack_pages[10] = 0x0 [ 0.167064] estack_pages[11] = 0xa10000000b000 [ 0.168055] estack_pages[12] = 0x0 [ 0.168891] BUG: unable to handle page fault for address: 0000000000001ff0