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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 6E65CC07E85 for ; Mon, 3 Dec 2018 10:23:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C60F20851 for ; Mon, 3 Dec 2018 10:23:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C60F20851 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=windriver.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726256AbeLCKXe (ORCPT ); Mon, 3 Dec 2018 05:23:34 -0500 Received: from mail5.windriver.com ([192.103.53.11]:58574 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726132AbeLCKXe (ORCPT ); Mon, 3 Dec 2018 05:23:34 -0500 Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail5.wrs.com (8.15.2/8.15.2) with ESMTPS id wB3AKP5h027153 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Mon, 3 Dec 2018 02:20:56 -0800 Received: from [128.224.162.162] (128.224.162.162) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 3 Dec 2018 02:20:20 -0800 Subject: Re: [PATCH] kernel/dma: Fix panic caused by passing swiotlb to command line To: Konrad Rzeszutek Wilk CC: , , , , , References: <1537154831-447363-1-git-send-email-zhe.he@windriver.com> <20181022192921.GA20677@dhcp-10-175-29-12.vpn.oracle.com> <87ee40fa-7a01-4d4c-7fa3-81aafc93e14f@windriver.com> <5fa82cb9-bd32-8a3f-ddca-053f544e2883@windriver.com> <20181202123032.GA3166@localhost.localdomain> From: He Zhe Message-ID: Date: Mon, 3 Dec 2018 18:20:16 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181202123032.GA3166@localhost.localdomain> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [128.224.162.162] Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/12/2 20:30, Konrad Rzeszutek Wilk wrote: > On Tue, Oct 30, 2018 at 07:06:10PM +0800, He Zhe wrote: >> >> On 2018/10/23 19:14, He Zhe wrote: >>> On 2018/10/23 03:29, Konrad Rzeszutek Wilk wrote: >>>> On Sat, Sep 22, 2018 at 08:56:58PM +0800, He Zhe wrote: >>>>> May I have your input? >>>> Alternatively would it make more sense for it to assume some default >>>> value? >>> Maybe, but the original code has no default value and I have no idea >>> what default value is proper here. >> Can anyone give some suggestions? Though I'd prefer to do nothing when >> no option is provided. > One provided the paramter for a reason. I would just do a small one, say > 4MB. OK. Thanks, I'll send v2. Zhe >> Thanks, >> Zhe >> >>> Zhe >>> >>>>> Thanks, >>>>> Zhe >>>>> >>>>> On 2018年09月17日 11:27, zhe.he@windriver.com wrote: >>>>>> From: He Zhe >>>>>> >>>>>> setup_io_tlb_npages does not check input argument before passing it >>>>>> to isdigit. The argument would be a NULL pointer if "swiotlb", without >>>>>> its value, is set in command line and thus causes the following panic. >>>>>> >>>>>> PANIC: early exception 0xe3 IP 10:ffffffffbb9b8e9f error 0 cr2 0x0 >>>>>> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #9 >>>>>> [ 0.000000] RIP: 0010:setup_io_tlb_npages+0xf/0x95 >>>>>> ... >>>>>> [ 0.000000] Call Trace: >>>>>> [ 0.000000] do_early_param+0x57/0x8e >>>>>> [ 0.000000] parse_args+0x208/0x320 >>>>>> [ 0.000000] ? rdinit_setup+0x30/0x30 >>>>>> [ 0.000000] parse_early_options+0x29/0x2d >>>>>> [ 0.000000] ? rdinit_setup+0x30/0x30 >>>>>> [ 0.000000] parse_early_param+0x36/0x4d >>>>>> [ 0.000000] setup_arch+0x336/0x99e >>>>>> [ 0.000000] start_kernel+0x6f/0x4e6 >>>>>> [ 0.000000] x86_64_start_reservations+0x24/0x26 >>>>>> [ 0.000000] x86_64_start_kernel+0x6f/0x72 >>>>>> [ 0.000000] secondary_startup_64+0xa4/0xb0 >>>>>> >>>>>> This patch adds a check to prevent the panic. >>>>>> >>>>>> Signed-off-by: He Zhe >>>>>> Cc: stable@vger.kernel.org >>>>>> Cc: konrad.wilk@oracle.com >>>>>> Cc: hch@lst.de >>>>>> Cc: m.szyprowski@samsung.com >>>>>> Cc: robin.murphy@arm.com >>>>>> --- >>>>>> kernel/dma/swiotlb.c | 5 +++++ >>>>>> 1 file changed, 5 insertions(+) >>>>>> >>>>>> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c >>>>>> index 4f8a6db..46fc34e 100644 >>>>>> --- a/kernel/dma/swiotlb.c >>>>>> +++ b/kernel/dma/swiotlb.c >>>>>> @@ -109,6 +109,11 @@ static int late_alloc; >>>>>> static int __init >>>>>> setup_io_tlb_npages(char *str) >>>>>> { >>>>>> + if (!str) { >>>>>> + pr_err("Config string not provided\n"); >>>>>> + return -EINVAL; >>>>>> + } >>>>>> + >>>>>> if (isdigit(*str)) { >>>>>> io_tlb_nslabs = simple_strtoul(str, &str, 0); >>>>>> /* avoid tail segment of size < IO_TLB_SEGSIZE */ >>>>> _______________________________________________ >>>>> iommu mailing list >>>>> iommu@lists.linux-foundation.org >>>>> https://lists.linuxfoundation.org/mailman/listinfo/iommu