From patchwork Fri Jan 27 16:00:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mukesh Ojha X-Patchwork-Id: 13118898 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 AC455C61DA3 for ; Fri, 27 Jan 2023 16:02:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231382AbjA0QC3 (ORCPT ); Fri, 27 Jan 2023 11:02:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231701AbjA0QC2 (ORCPT ); Fri, 27 Jan 2023 11:02:28 -0500 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A6368662B; Fri, 27 Jan 2023 08:01:58 -0800 (PST) Received: from pps.filterd (m0279862.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30RFe8eR015045; Fri, 27 Jan 2023 16:01:17 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=qcppdkim1; bh=0tcHV/Dlv4ShFcIEmal26a+260D96f+aRw22smTtopg=; b=XCeVdyiJahzmOHaQQU1tZo3A+xdL46kAJY4/fDJ6QJJhm4/oSQZ0Gh1hevWeNdASHAdJ VCWpqgKxE3V5iykoDQO5/aP3lT3/ibD7BKEVbm955XGbI2resdFyJ9/7pUJOPGWLC9Xm GSm/pLdMyuoAwKDS+noPq6o6/eFHMX1iMkfxzn3RykEs5aYrFzS7tkQv/8slcE41p65x Vui8LEO7J1qX8ulnl3hsnVEsdT76GUigZAlm9hOh/0jjYOFnU4vs/9x9xM9u7wUYUvzk U2VGWiSbCyANfWf/cA5ybeTAAoL4t2EmJyJuxSNyhZ0GqIQg3zpdChOYiGw9Wvpy2SPJ 4g== Received: from nasanppmta01.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3ncheyr1sr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 27 Jan 2023 16:01:17 +0000 Received: from nasanex01c.na.qualcomm.com (nasanex01c.na.qualcomm.com [10.45.79.139]) by NASANPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 30RG1GGO024374 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 27 Jan 2023 16:01:16 GMT Received: from hu-mojha-hyd.qualcomm.com (10.80.80.8) by nasanex01c.na.qualcomm.com (10.45.79.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Fri, 27 Jan 2023 08:01:13 -0800 From: Mukesh Ojha To: , , , CC: Mukesh Ojha , Kees Cook , Tony Luck , "Guilherme G. Piccoli" , Jonathan Corbet Subject: [PATCH v4 2/2] pstore/ram: Rework logic for detecting ramoops Date: Fri, 27 Jan 2023 21:30:52 +0530 Message-ID: <1674835252-31954-2-git-send-email-quic_mojha@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1674835252-31954-1-git-send-email-quic_mojha@quicinc.com> References: <1674835252-31954-1-git-send-email-quic_mojha@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01c.na.qualcomm.com (10.45.79.139) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: 1PNxq6JX5Cssz7Mn4WBvlVKsFESOd5Yh X-Proofpoint-GUID: 1PNxq6JX5Cssz7Mn4WBvlVKsFESOd5Yh X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.122.1 definitions=2023-01-27_09,2023-01-27_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 phishscore=0 adultscore=0 mlxscore=0 clxscore=1015 bulkscore=0 mlxlogscore=999 spamscore=0 suspectscore=0 lowpriorityscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2301270148 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org The reserved memory region for ramoops is assumed to be at a fixed and known location when read from the devicetree. This is not desirable in an environment where it is preferred the region to be dynamically allocated at runtime, as opposed to being fixed at compile time. Also, some of the platforms might be still expecting dedicated memory region for ramoops node where the region is known beforehand and platform_get_resource() is used in that case. So, add logic to detect the start and size of the ramoops memory region by looking up reserved memory region with of_reserved_mem_lookup() api when platform_get_resource() fails also update the ramoops documentation, Cc: Kees Cook Cc: Tony Luck Cc: "Guilherme G. Piccoli" Cc: Jonathan Corbet Signed-off-by: Mukesh Ojha --- Changes in v4: - Updated the minor change in documentation. Changes in v3: - Merged 2/3 and 3/3 into one. https://lore.kernel.org/lkml/1673611126-13803-2-git-send-email-quic_mojha@quicinc.com/ https://lore.kernel.org/lkml/1673611126-13803-3-git-send-email-quic_mojha@quicinc.com/ Changes in v2: - Addressed the comments made by kees and Guilherme in v1. Documentation/admin-guide/ramoops.rst | 25 ++++++++++++++++++++++--- fs/pstore/ram.c | 18 +++++++++++++----- 2 files changed, 35 insertions(+), 8 deletions(-) diff --git a/Documentation/admin-guide/ramoops.rst b/Documentation/admin-guide/ramoops.rst index e9f8514..f701fab 100644 --- a/Documentation/admin-guide/ramoops.rst +++ b/Documentation/admin-guide/ramoops.rst @@ -16,8 +16,9 @@ survive after a restart. Ramoops concepts ---------------- -Ramoops uses a predefined memory area to store the dump. The start and size -and type of the memory area are set using three variables: +Ramoops uses both predefined and dynamically memory area to store the dump. +The start and size and type of the memory area are set using three +variables: * ``mem_address`` for the start * ``mem_size`` for the size. The memory size will be rounded down to a @@ -70,7 +71,8 @@ Setting the ramoops parameters can be done in several different manners: B. Use Device Tree bindings, as described in ``Documentation/devicetree/bindings/reserved-memory/ramoops.yaml``. - For example:: + + Example of statically reserved ramoops region:: reserved-memory { #address-cells = <2>; @@ -85,6 +87,23 @@ Setting the ramoops parameters can be done in several different manners: }; }; + Example of dynamically reserved ramoops region:: + + reserved-memory { + #address-cells = <1>; + #size-cells = <1>; + ranges; + + ramoops_region: ramoops { + compatible = "ramoops"; + alloc-ranges = <0x00000000 0xffffffff>; + size = <0 0x100000>; + record-size = <0x4000>; + console-size = <0x4000>; + }; + }; + + C. Use a platform device and set the platform data. The parameters can then be set through that platform data. An example of doing that is: diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index ade66db..17c9f46 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "internal.h" #include "ram_internal.h" @@ -643,6 +644,7 @@ static int ramoops_parse_dt(struct platform_device *pdev, { struct device_node *of_node = pdev->dev.of_node; struct device_node *parent_node; + struct reserved_mem *rmem; struct resource *res; u32 value; int ret; @@ -651,13 +653,19 @@ static int ramoops_parse_dt(struct platform_device *pdev, res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { - dev_err(&pdev->dev, - "failed to locate DT /reserved-memory resource\n"); - return -EINVAL; + rmem = of_reserved_mem_lookup(of_node); + if (!rmem) { + dev_err(&pdev->dev, + "failed to locate DT /reserved-memory resource\n"); + return -EINVAL; + } + pdata->mem_size = rmem->size; + pdata->mem_address = rmem->base; + } else { + pdata->mem_size = resource_size(res); + pdata->mem_address = res->start; } - pdata->mem_size = resource_size(res); - pdata->mem_address = res->start; /* * Setting "unbuffered" is deprecated and will be ignored if * "mem_type" is also specified.