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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 A3453C433E4 for ; Thu, 13 Aug 2020 10:17:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 864FC21744 for ; Thu, 13 Aug 2020 10:17:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726419AbgHMKRQ (ORCPT ); Thu, 13 Aug 2020 06:17:16 -0400 Received: from foss.arm.com ([217.140.110.172]:52938 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726204AbgHMKRP (ORCPT ); Thu, 13 Aug 2020 06:17:15 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2A8B931B; Thu, 13 Aug 2020 03:17:14 -0700 (PDT) Received: from [10.37.8.11] (unknown [10.37.8.11]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AE62A3F70D; Thu, 13 Aug 2020 03:17:02 -0700 (PDT) Subject: Re: [PATCH] coresight: fix offset by one error in counting ports To: ykaukab@suse.de, linux-arm-kernel@lists.infradead.org, mathieu.poirier@linaro.org Cc: linux-kernel@vger.kernel.org, alexander.shishkin@linux.intel.com, mike.leach@linaro.org, gregkh@linuxfoundation.org, tingwei@codeaurora.org, ro@suse.com, jeremy.linton@arm.com References: <20200813100456.11803-1-ykaukab@suse.de> <20200813100456.11803-2-ykaukab@suse.de> From: Suzuki K Poulose Message-ID: <213e9d02-b945-1317-bc54-83b64ac376cf@arm.com> Date: Thu, 13 Aug 2020 11:22:05 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20200813100456.11803-2-ykaukab@suse.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/13/2020 11:04 AM, Mian Yousaf Kaukab wrote: > Since port-numbers start from 0, add 1 to port-number to get the port > count. > > Fix following crash when Coresight is enabled on ACPI based systems: > > [ 61.061736] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 > ... > [ 61.135494] pc : acpi_coresight_parse_graph+0x1c4/0x37c > [ 61.140705] lr : acpi_coresight_parse_graph+0x160/0x37c > [ 61.145915] sp : ffff800012f4ba40 > [ 61.145917] x29: ffff800012f4ba40 x28: ffff00becce62f98 > [ 61.159896] x27: 0000000000000005 x26: ffff00becd8a7c88 > [ 61.165195] x25: ffff00becd8a7d88 x24: ffff00becce62f80 > [ 61.170492] x23: ffff800011ef99c0 x22: ffff009efb8bc010 > [ 61.175790] x21: 0000000000000018 x20: 0000000000000005 > [ 61.181087] x19: ffff00becce62e80 x18: 0000000000000020 > [ 61.186385] x17: 0000000000000001 x16: 00000000000002a8 > [ 61.191682] x15: ffff000838648550 x14: ffffffffffffffff > [ 61.196980] x13: 0000000000000000 x12: ffff00becce62d87 > [ 61.202277] x11: 00000000ffffff76 x10: 000000000000002e > [ 61.207575] x9 : ffff8000107e1a68 x8 : ffff00becce63000 > [ 61.212873] x7 : 0000000000000018 x6 : 000000000000003f > [ 61.218170] x5 : 0000000000000000 x4 : 0000000000000000 > [ 61.223467] x3 : 0000000000000000 x2 : 0000000000000000 > [ 61.228764] x1 : ffff00becce62f80 x0 : 0000000000000000 > [ 61.234062] Call trace: > [ 61.236497] acpi_coresight_parse_graph+0x1c4/0x37c > [ 61.241361] coresight_get_platform_data+0xdc/0x130 > [ 61.246225] tmc_probe+0x138/0x2dc > [ 61.246227] amba_probe+0xdc/0x220 > [ 61.255779] really_probe+0xe8/0x49c > [ 61.255781] driver_probe_device+0xec/0x140 > [ 61.255782] device_driver_attach+0xc8/0xd0 > [ 61.255785] __driver_attach+0xac/0x180 > [ 61.265857] bus_for_each_dev+0x78/0xcc > [ 61.265859] driver_attach+0x2c/0x40 > [ 61.265861] bus_add_driver+0x150/0x244 > [ 61.265863] driver_register+0x80/0x13c > [ 61.273591] amba_driver_register+0x60/0x70 > [ 61.273594] tmc_driver_init+0x20/0x2c > [ 61.281582] do_one_initcall+0x50/0x230 > [ 61.281585] do_initcalls+0x104/0x144 > [ 61.291831] kernel_init_freeable+0x168/0x1dc > [ 61.291834] kernel_init+0x1c/0x120 > [ 61.299215] ret_from_fork+0x10/0x18 > [ 61.299219] Code: b9400022 f9400660 9b277c42 8b020000 (f9400404) > [ 61.307381] ---[ end trace 63c6c3d7ec6a9b7c ]--- > [ 61.315225] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > > Fixes: d375b356e687 ("coresight: Fix support for sparsely populated ports") > Reported-by: Ruediger Oertel > Signed-off-by: Mian Yousaf Kaukab > --- > drivers/hwtracing/coresight/coresight-platform.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c > index bfd44231d7ad..227e234a2470 100644 > --- a/drivers/hwtracing/coresight/coresight-platform.c > +++ b/drivers/hwtracing/coresight/coresight-platform.c > @@ -711,11 +711,11 @@ static int acpi_coresight_parse_graph(struct acpi_device *adev, > return dir; > > if (dir == ACPI_CORESIGHT_LINK_MASTER) { > - if (ptr->outport > pdata->nr_outport) > - pdata->nr_outport = ptr->outport; > + if (ptr->outport >= pdata->nr_outport) > + pdata->nr_outport = ptr->outport + 1; > ptr++; > } else { > - WARN_ON(pdata->nr_inport == ptr->child_port); > + WARN_ON(pdata->nr_inport == ptr->child_port + 1); > /* > * We do not track input port connections for a device. > * However we need the highest port number described, > @@ -723,8 +723,8 @@ static int acpi_coresight_parse_graph(struct acpi_device *adev, > * record for an output connection. Hence, do not move > * the ptr for input connections > */ > - if (ptr->child_port > pdata->nr_inport) > - pdata->nr_inport = ptr->child_port; > + if (ptr->child_port >= pdata->nr_inport) > + pdata->nr_inport = ptr->child_port + 1; > } > } I was about to post a similar fix following a report from Jeremy. This looks fine to me. Reviewed-by: Suzuki K Poulose