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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS 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 E7B88C282C0 for ; Wed, 23 Jan 2019 07:05:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0ADA20870 for ; Wed, 23 Jan 2019 07:05:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="lku0bWzb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726309AbfAWHFQ (ORCPT ); Wed, 23 Jan 2019 02:05:16 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:7957 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726134AbfAWHFQ (ORCPT ); Wed, 23 Jan 2019 02:05:16 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 22 Jan 2019 23:04:39 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 22 Jan 2019 23:05:14 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 22 Jan 2019 23:05:14 -0800 Received: from [10.24.242.22] (172.20.13.39) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 23 Jan 2019 07:05:05 +0000 Subject: Re: kmemleak panic To: Mike Rapoport , Marc Gonzalez CC: Rob Herring , Catalin Marinas , Sachin Nikam , John Hubbard , Ralph Campbell , Robin Murphy , Frank Rowand , Marek Szyprowski , Bjorn Andersson , Mark Rutland , Arnd Bergmann , Ard Biesheuvel , Oscar Salvador , Wei Yang , Michal Hocko , Andrew Morton , Linus Torvalds , Qian Cai , LKML , , References: <20190119132832.GA29881@MBP.local> <6579db26-10ac-3fbf-1998-5b937a38f202@free.fr>

<20190121143704.GE29504@arrakis.emea.arm.com> <20190121174234.GC26461@rapoport-lnx> <2bb30550-435a-046c-4f45-21dd594aa695@free.fr> <3c886941-bf9d-f040-b568-ee7a8eba9a04@free.fr> <20190123055414.GA4747@rapoport-lnx> From: Prateek Patel Message-ID: <5e5be6bc-5fc1-5def-d1b8-dc2fa4bbc93e@nvidia.com> Date: Wed, 23 Jan 2019 12:35:01 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.3 MIME-Version: 1.0 In-Reply-To: <20190123055414.GA4747@rapoport-lnx> X-Originating-IP: [172.20.13.39] X-ClientProxiedBy: HQMAIL103.nvidia.com (172.20.187.11) To HQMAIL101.nvidia.com (172.20.187.10) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-GB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1548227079; bh=XqLNJAxvj6WFZ0l03Rch4zfDuGF6h7Hpt/ajtk8MdT4=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Transfer-Encoding: Content-Language; b=lku0bWzbbKgl/BPsCqUDjxTE2TnC1ob9pdgEtn+6Jtm1u7dIBWkn8PVY90ZM3bOPC d+fvQuIACpZjFfnH234D2avmPGKiThatt9vfEn9u2b+6xbw3L1aJ6B5mk3IWM8YTcJ 6FPezTD7MQGb6JFC5GluCC/QpthvZ4jpM3pOZte1LczY1w5snU3uJpE1Es63CMErB2 N+Lt3HKt45mVz71QvPOayMxuGNLrL7B1hz83s+TKOh8jQOk69ycLPUU2OgAfZ56dxN wN+B2fBcjXgkzW3LvIF3qf+U8Pps+gth9d+iV3f0NAxfcfFoeyC+CBn64cI3r10N23 uRSKvpPBXjr1Q== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/23/2019 11:24 AM, Mike Rapoport wrote: > On Tue, Jan 22, 2019 at 03:12:54PM +0100, Marc Gonzalez wrote: >> On 22/01/2019 15:02, Marc Gonzalez wrote: >> >>> On 21/01/2019 18:42, Mike Rapoport wrote: >>> >>>> If I understood correctly, the trouble comes from no-map range allocated in >>>> early_init_dt_alloc_reserved_memory_arch(). >>>> >>>> There's indeed imbalance, because memblock_alloc() does kmemleak_alloc(), but >>>> memblock_remove() does not do kmemleak_free(). >>>> >>>> I think the best way is to replace __memblock_alloc_base() with >>>> memblock_find_in_range(), e.g something like: >>>> >>>> >>>> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c >>>> index 1977ee0adcb1..6807a1cffe55 100644 >>>> --- a/drivers/of/of_reserved_mem.c >>>> +++ b/drivers/of/of_reserved_mem.c >>>> @@ -37,21 +37,16 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, >>>> */ >>>> end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end; >>>> align = !align ? SMP_CACHE_BYTES : align; >>>> - base = __memblock_alloc_base(size, align, end); >>>> + base = memblock_find_in_range(size, align, start, end); >>>> if (!base) >>>> return -ENOMEM; >>>> >>>> - /* >>>> - * Check if the allocated region fits in to start..end window >>>> - */ >>>> - if (base < start) { >>>> - memblock_free(base, size); >>>> - return -ENOMEM; >>>> - } >>>> - >>>> *res_base = base; >>>> if (nomap) >>>> return memblock_remove(base, size); >>>> + else >>>> + return memblock_reserve(base, size); >>>> + >>>> return 0; >>>> } >>>> >>> Your patch solves the issue. \o/ > Great :) > >> [ Add nvidia devs, but drop schowdary@nvidia.com ] >> > Resending it as a formal patch now, I took a liberty to add your Tested-by. > > From a847ca684db29a3c09e4dd2a8a008b35cf36e52f Mon Sep 17 00:00:00 2001 > From: Mike Rapoport > Date: Wed, 23 Jan 2019 07:38:50 +0200 > Subject: [PATCH] of: fix kmemleak crash caused by imbalance in early memory > reservation > > Marc Gonzalez reported the following kmemleak crash: > > Unable to handle kernel paging request at virtual address ffffffc021e00000 > Mem abort info: > ESR = 0x96000006 > Exception class = DABT (current EL), IL = 32 bits > SET = 0, FnV = 0 > EA = 0, S1PTW = 0 > Data abort info: > ISV = 0, ISS = 0x00000006 > CM = 0, WnR = 0 > swapper pgtable: 4k pages, 39-bit VAs, pgdp = (____ptrval____) > [ffffffc021e00000] pgd=000000017e3ba803, pud=000000017e3ba803, > pmd=0000000000000000 > Internal error: Oops: 96000006 [#1] PREEMPT SMP > Modules linked in: > CPU: 6 PID: 523 Comm: kmemleak Tainted: G S W 5.0.0-rc1 #13 > Hardware name: Qualcomm Technologies, Inc. MSM8998 v1 MTP (DT) > pstate: 80000085 (Nzcv daIf -PAN -UAO) > pc : scan_block+0x70/0x190 > lr : scan_block+0x6c/0x190 > sp : ffffff8012e8bd20 > x29: ffffff8012e8bd20 x28: ffffffc0fdbaf018 > x27: ffffffc022000000 x26: 0000000000000080 > x25: ffffff8011aadf70 x24: ffffffc0f8cc8000 > x23: ffffff8010dc8000 x22: ffffff8010dc8830 > x21: ffffffc021e00ff9 x20: ffffffc0f8cc8050 > x19: ffffffc021e00000 x18: 0000000000002409 > x17: 0000000000000200 x16: 0000000000000000 > x15: ffffff8010e14dd8 x14: 0000000000002406 > x13: 000000004c4dd0c6 x12: ffffffc0f77dad58 > x11: 0000000000000001 x10: ffffff8010d9e688 > x9 : ffffff8010d9f000 x8 : ffffff8010d9e688 > x7 : 0000000000000002 x6 : 0000000000000000 > x5 : ffffff8011511c20 x4 : 00000000000026d1 > x3 : ffffff8010e14d88 x2 : 5b36396f4e7d4000 > x1 : 0000000000208040 x0 : 0000000000000000 > Process kmemleak (pid: 523, stack limit = 0x(____ptrval____)) > Call trace: > scan_block+0x70/0x190 > scan_gray_list+0x108/0x1c0 > kmemleak_scan+0x33c/0x7c0 > kmemleak_scan_thread+0x98/0xf0 > kthread+0x11c/0x120 > ret_from_fork+0x10/0x1c > Code: f9000fb4 d503201f 97ffffd2 35000580 (f9400260) > ---[ end trace 176d6ed9d86a0c33 ]--- > note: kmemleak[523] exited with preempt_count 2 > > The crash happens when a no-map area is allocated in > early_init_dt_alloc_reserved_memory_arch(). The allocated region is > registered with kmemleak, but it is then removed from memblock using > memblock_remove() that is not kmemleak-aware. > > Replacing __memblock_alloc_base() with memblock_find_in_range() makes sure > that the allocated memory is not added to kmemleak and then > memblock_remove()'ing this memory is safe. > > As a bonus, since memblock_find_in_range() ensures the allocation in the > specified range, the bounds check can be removed. > > Signed-off-by: Mike Rapoport > Tested-by: Marc Gonzalez > --- > drivers/of/of_reserved_mem.c | 13 ++++--------- > 1 file changed, 4 insertions(+), 9 deletions(-) > > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c > index 1977ee0adcb1..6807a1cffe55 100644 > --- a/drivers/of/of_reserved_mem.c > +++ b/drivers/of/of_reserved_mem.c > @@ -37,21 +37,16 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, > */ > end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end; > align = !align ? SMP_CACHE_BYTES : align; > - base = __memblock_alloc_base(size, align, end); > + base = memblock_find_in_range(size, align, start, end); > if (!base) > return -ENOMEM; > > - /* > - * Check if the allocated region fits in to start..end window > - */ > - if (base < start) { > - memblock_free(base, size); > - return -ENOMEM; > - } > - > *res_base = base; > if (nomap) > return memblock_remove(base, size); > + else > + return memblock_reserve(base, size); > + > return 0; > } > Thanks Mike for the patch. With this, skipping kmemleak scan: https://patchwork.ozlabs.org/patch/995367/ is not required.