From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 055711EA80 for ; Tue, 14 Jan 2025 00:23:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.177.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736814183; cv=fail; b=CX1yQzztx1PacoN5pG/Vi96zlwrekFqUh+J0IQMRBX+odQHmY6e81z02a2n9H8RAIRTQ5H9qOcn+w4JX5xZI0Hb7fABxH4Xg0JBA/b/s8MF9kuYENhmkG4H7qUVbvirpNelBUk6TFy98JzhiFZqBUmjzuCmbPIUAQ/b+6bQOTV0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736814183; c=relaxed/simple; bh=hmYSpJttX7oQ9FMl+vVaREYu8YnYk69Y1Oq2ZCbI5QE=; h=From:To:CC:Subject:Date:Message-ID:Content-Type:MIME-Version; b=K+6EKfZxcmI4pU3vuXOn8uI2k5HwhX7YmuWeroKVbDl1HBzC7fps6fE26w+NexZkTwx1rqAEMkgeIi4wMnMsdv6v7opBgSzJzhuousDL2cyqYpkzDvcH8+VGomlKaTW2fhFhgqoXJscSvU9GMFO14LAltCoszHDF9FxA/KSS9dQ= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=D8pI2Dcl; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=xkHRv/qc; arc=fail smtp.client-ip=205.220.177.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="D8pI2Dcl"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="xkHRv/qc" Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 50DMB3tR029685; Tue, 14 Jan 2025 00:22:05 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:message-id:mime-version:subject:to; s= corp-2023-11-20; bh=SEJ10iQL/uXjDbAjUJzC+dVHp3ey5a6n7BCIUyDgWu4=; b= D8pI2Dclj6tXJMkT9cAn/PZfoH13C7fK7q/3sj2qcG1ayGp+mwwgui0sisraPmtZ /IRyKQDWg+scNyC34Yhd/MTE5XmLGVDTk3idTxvd8PAErMtS+wVHmoUUQVHD7otk XU7u5xT9r6KHQ4uKT3QbSUt6y0oLxC1JqHs9jE6tNIDWwxifGzscpZZry4vPZRsk e/LC50FFyCsa31mY0NOSagEuH9ZS6O3DteJ4DXhfiV7S7DKGGi6H7pqLpbyIdiit MC+ujAZ1mScF4qt2OxX+bUx74JHu2BcxuyU9ZCiTj/qNc/bIwpTXDDCXzM3WgBo0 9Z6l179V9CKbrtwKmfVrrQ== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 443g8scthm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 14 Jan 2025 00:22:05 +0000 (GMT) Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 50E0HFIF036418; Tue, 14 Jan 2025 00:22:05 GMT Received: from nam12-bn8-obe.outbound.protection.outlook.com (mail-bn8nam12lp2175.outbound.protection.outlook.com [104.47.55.175]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 443f384ym2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 14 Jan 2025 00:22:04 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=e3HYzlam4G2V/Yydm12hNykX2/El1gfPo4HzAehYI3qJoWfhfCKbwa0mEB8OB176En3yQAx33+eyepEWRDZW0DP54jjq7mozATrnE5wAf8Rb6zfrydU+ruVsyAcSdLLuoZdOmgelHI3wCv88xHY7ibfVcy2PsdF9+LyMfnnAFpjqpEe4LsGWmrbtdGCAtBoxrYNi6t5CDpaU5W+nGe/9gRORopmQuNzCuxZh4x4n8sfo6l7ge16NaxG2Ck2BdSgAuGu0WmkhGxNnWBrE1Upy5ma5/CVd7YoEg+bkquzHPR/EeyTajJ4WCDMliThLq1eztJbgVQ5JsTGeBrQlUVJrKQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=SEJ10iQL/uXjDbAjUJzC+dVHp3ey5a6n7BCIUyDgWu4=; b=Qtz9f6caUmVZqDTASfjUMe498Y8OL3TvRj+AiBGzlVqpKOwx4H8okyM3dz9sYS+hMDkSs6SblCj9lKLyfJ2REjjioQzWvPjJg61dkonmj4KvofDcDnSgo2Pkb828a59n225fu5XtNQUH7MYhL9re8zp7tja90v5jAsIGqyvojx0nZV/L0NTrSzCukF0vraWBplG6bQEoMqeB661++A1HbvE3+gkRnfScsMwHxDj8BemXGg7G8QoHQFSGwoGM9DH1m083M+VbjGVEz4hW9HdB3rXtSwU+rhabZ8q6xZtvj3whSiDKlLe6zIC8dhCy9v+XDGzavri2e9x8v+axsEhWhQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=SEJ10iQL/uXjDbAjUJzC+dVHp3ey5a6n7BCIUyDgWu4=; b=xkHRv/qcWivsU+o9WGP7aUFRT7daecC+OYioam+M1BE4WXZToAwMOeZj7rA0W/AVhgyU4SUwJzuelV7d45csg6hzKHwo1ZsrBZ0R8dUfu4FP/NJ+QLyj4Ty+Gu53K7+yUiaceaOqa89fGHZLxIMVbpkpTLpg3KioF7oXXPQprmI= Received: from PH8PR10MB6597.namprd10.prod.outlook.com (2603:10b6:510:226::20) by SJ0PR10MB5801.namprd10.prod.outlook.com (2603:10b6:a03:423::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8335.18; Tue, 14 Jan 2025 00:22:03 +0000 Received: from PH8PR10MB6597.namprd10.prod.outlook.com ([fe80::6874:4af6:bf0a:6ca]) by PH8PR10MB6597.namprd10.prod.outlook.com ([fe80::6874:4af6:bf0a:6ca%4]) with mapi id 15.20.8335.017; Tue, 14 Jan 2025 00:22:03 +0000 From: Stephen Brennan To: binutils@sourceware.org CC: , Omar Sandoval , Amal Raj T Subject: GDB Remote Protocol Extension - Linux VMCOREINFO - Request for Feedback Date: Mon, 13 Jan 2025 16:22:00 -0800 Message-ID: <8734hmtfbr.fsf@oracle.com> Content-Type: text/plain X-ClientProxiedBy: BN6PR17CA0052.namprd17.prod.outlook.com (2603:10b6:405:75::41) To PH8PR10MB6597.namprd10.prod.outlook.com (2603:10b6:510:226::20) Precedence: bulk X-Mailing-List: linux-debuggers@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR10MB6597:EE_|SJ0PR10MB5801:EE_ X-MS-Office365-Filtering-Correlation-Id: aec0664a-3967-49fb-041c-08dd34317812 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?svuUWhczjXZ+QcUTSy2V5rH4T3WfqGbjKgkyn1Xl82fCqrbB+JU/Ol2cIUd0?= =?us-ascii?Q?DrqGwXmqCJ6q7XH1Y6kA0TxhfhjLQElfCLTsdZ5E3c/1QDLVJvNfJVsIVYz6?= =?us-ascii?Q?FtRquWV2wlFaxgtYc7hgep0ti5xTRhfTU+3tsinl4AOV+2odx4C0sHfioYAM?= =?us-ascii?Q?QRIZiesJnRKgrAtO/s8SBescnIoTWscbTzGvfuoe+JSCQIOtt/B5S9bSjya3?= =?us-ascii?Q?vB/Z5Z87PKWCTZSj5zwa86lnNsm+JOjAABl9fwp2HFQX+TnDOD1fe6PjthLt?= =?us-ascii?Q?mhCgHVTqOLLYRe3gL3PPHLxr79qBgF0pTebFw7Px/30wPJayNKZTA3TzvdY6?= =?us-ascii?Q?c1Q/kDSjqQ/xUWNqk4Q0eunc4f7qrV9E2xE3wCbNIMP98P/sVSVcs0mSApJq?= =?us-ascii?Q?Y7MPqk90nqZfRNmiSYHcY6gRxPmqouaN4gyWf2U4LzVlQqqsKDGPv7hApjPg?= =?us-ascii?Q?JNml2/S2FHJKTaz7+DpfO6F89d8YJTwDpTZrB5v6vjO2xYhvv+RFRasONWl9?= =?us-ascii?Q?UDsZgHvB5lvOF5DmZe1YSzK5luYa+jrE6lYGjaLLnrqJ+K9vtGeZdlCCvQ6m?= =?us-ascii?Q?svargyuwdakqbHoJ3XyiisCQYDGS18Jb8O6hqEQ2yndNCDPhrw6yjBJ4P6O8?= =?us-ascii?Q?7RDO756HHO1UBSAW0gGD2NieACvEGc6YXt2PHT30rL6RITBKWJsYvF/Nu+Kq?= =?us-ascii?Q?n4u+4lzsnSqco9cxhKIUL4hGPaxBM8UYlFRc9tGWvpFZXDchJP4q7PdMETpd?= =?us-ascii?Q?0aW0VOU4r9H/aWfc11gd7k29m3Uya73X5rXaho7QOkVCKY7b7QJDC7Z/fY70?= =?us-ascii?Q?bEm84xKCORX86SMoAFPLrb4GZ/meqnEhYRCoRQuYleZXwRaNhbKiPOt+iGLJ?= =?us-ascii?Q?0YuYjiHPvZx/T6Y7vhCbkT0PD7cabpBi3IX7Hqp9pFUDDeZ16lrqMwuCBu/p?= =?us-ascii?Q?/r/0R+8cq8LnPJq+OkBzyIEdWU42PCUDzHaav/z6eaWzM3xSA0utODe57omu?= =?us-ascii?Q?3GJtXUsWvlobc0KasRFR8ZAz4Qer2jUL61xSD6T8g+76u16+Yu+yDV2dM3Tr?= =?us-ascii?Q?NqG8b91QrGlHpGT0vnhMpCbb9YJYiAgXJxD/OecpqdXaj9hUgf6shIDicbjj?= =?us-ascii?Q?0SUntTADxcX54bYWJYuZHTAam9lS1+yq/INxZWuolJI39XtGydRgzma8ojYW?= =?us-ascii?Q?790kS+nTOBuJRiuxqkjy7Ql/fgSoDThWNl/2j5ONwC4h3bl131QFfwZ51VJR?= =?us-ascii?Q?h8a7+6bhUcvL3qoDSxjRmpItbUX9LIOYqa1hbJrLFIgpPkOfE+OBVBGqJLiI?= =?us-ascii?Q?Y6qKzmuqYPSTLIWYkadvsWe0IpZpSdGMq7qSlBhpytYD5w=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH8PR10MB6597.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?pyiMXPs0L6RJwWbk4e8+694+IFdZ62LADnQ2ca/Kep/YpJuGlLPsq/Cov6xe?= =?us-ascii?Q?0muE9IxxIpA5cExdjBqQVeEfvv6bH1oGRgRsfbFkDjprVMC+Ut+dBK7oCCII?= =?us-ascii?Q?RvJ/wAd6wz1ei442tGwkBPJAfHOON8rZGTz4BGAA165lA2pXwGvQ6xc41mv3?= =?us-ascii?Q?MZ+D2JunmSprXqeEM5oTjG7zNFkdL7MjKGcUgyB+jMsVAbziGSzFhtVtyuLX?= =?us-ascii?Q?bN8hyibQj1kxdB8LkK5AkGOIRcTog0wzQWs2XT9XdS0h7SKMyXvTh+a/Ktd5?= =?us-ascii?Q?2f3s7efmjaVqTlv68pva1pqGt8WSqMfEWAh1bnDNtypbrbJMFDd8OORblPIP?= =?us-ascii?Q?8CctYFvrF6UDoLeOMyIiU975LKlk9PPILwoua5rQ9beuAmjMe5tUqrEnt1FJ?= =?us-ascii?Q?GirO4Ac53YnuHxg1qf3YDLsOJlpK6ULbvmxoV/LtqQFq8gtg7hbB4RtC1DZd?= =?us-ascii?Q?tpkFQch4atJvDdGZOKeWcYZDwLTzkzmZjGffy3rvTBTryh/LrwLhxKFM8TQF?= =?us-ascii?Q?7C1YsEdgXOV82k456wjAxLopPSAf8Ty0x8UgrYwlV8MamF6mguks1xGQ1Mkh?= =?us-ascii?Q?voJxszItox9zb+XvGakebKCAzypOLrD4YorCCGPZwSxqwkcLpnGbv/+3gOOk?= =?us-ascii?Q?LGlJCbJqz3xd1d3yjk9wUoFSXfOIQMhwoo8Rd4k7LZ37cF1j6jQ+sM45amSS?= =?us-ascii?Q?LXuqHSSv7PC0M+R9dwabTJXjbZvnJgm3OCEDxaBIoWEOLTbYNx6SRCaY9lq6?= =?us-ascii?Q?wnhK/ohckB+/VN7EgJLdwMhvx0ZYhfY3BBM/6mrLw+V+ISSkz0reX2+0ns7C?= =?us-ascii?Q?ooxReygli1G1BhkL+77HcldGzp2n71/fLZg/1sHx6D2akGdrEdqU4tKHQ/rG?= =?us-ascii?Q?wR2uReZpX8Ir5v8T4C2sAH3YhaTa3fnRF85wMbY2Oqt8k3dqvEF7AXiFuoDj?= =?us-ascii?Q?GbdRN6sFJMg3pgitBie8t/hu2PHr/XZw7pLaFiSZkLTheHHgA4mvaf83Ityu?= =?us-ascii?Q?MB05YS8h4Zg62ppojaY5Goy0GAapMQbOUaiwWTgjxh60g1xsDC8IlnttR4rT?= =?us-ascii?Q?ivJ2B+NH+XYtTB50bgolNquILd7kXQzEgVfudMTcU77l9shg72tsHow3HZom?= =?us-ascii?Q?dA94avfJOSxUh8ae9CLkH+wP76TQAwhx81/7X1UTKfIID+ism449eyFyM1J9?= =?us-ascii?Q?YUJbL3IGwAzWZdkjooLjt/rYikBZCRCudD9RslZlAhRfNnHOZNQVWagz3Rfw?= =?us-ascii?Q?t2PxaBngplluodQzSIJJPGxHbEp3PlL3zIVKr5p0xL+vGg+kKTqZ24Y3owaf?= =?us-ascii?Q?UzwZ/OlMvJ3ZCa91Klep9ojxLgYOl+4UkcDkJQq00FVvZ8ICvUeSyFf679wB?= =?us-ascii?Q?kRLgwy3rTo2LkzD2QHMfGZyIbEE3G56lwxUlzQV1a4FUEbCWr6FJL1eAn9Rn?= =?us-ascii?Q?J/aEvjJikQ0oj4ANgWnz8HTnn3AV111xkchsTK+Ltlci5A0rMEThfYNLXfMG?= =?us-ascii?Q?XL12Pm8nN+hJZZE8B3RtTcAlXjYGnqrGqFAzM4zmwAWMUM+7IQIBkWv1SVJo?= =?us-ascii?Q?D8njlZMX8nzXv/QKE2UEF0Q18qwD38TM0pxngtTIAqLwj/MVR8fO3CvnZ5SL?= =?us-ascii?Q?Rg=3D=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: aec0664a-3967-49fb-041c-08dd34317812 X-MS-Exchange-CrossTenant-AuthSource: PH8PR10MB6597.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Jan 2025 00:22:03.1021 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: H85sRgBUt+854oCuWCmeYHZ+zjlObIP1ZUyuucS0u0MFbKgXJlSDXTsjHP4CCr5+5yvCbvlu4npzO3IMhOb5VLjfiKyL5+c/qCfk4fpMAOE= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR10MB5801 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-01-13_09,2025-01-13_02,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 malwarescore=0 spamscore=0 suspectscore=0 mlxlogscore=999 adultscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2411120000 definitions=main-2501140001 X-Proofpoint-GUID: 4ifmLdI9sEoJXUZBdnY-WeeLXLTpho1y X-Proofpoint-ORIG-GUID: 4ifmLdI9sEoJXUZBdnY-WeeLXLTpho1y Hello all, I contribute to the drgn debugger [1], and work on debugging the Linux kernel a fair bit. Drgn is particularly well-suited to the Linux kernel and contains a lot of support for it. It currently supports attaching to live targets via Linux's /proc/kcore, and core dumps. We are looking into supporting remote targets via GDB's remote protocol. One piece of information that is very useful when debugging the Linux kernel is the VMCOREINFO note[2]. This is a free-form piece of text data, typically around 3k bytes, which contains information that debuggers would find useful in interpreting a Linux kernel memory image. In particular, it contains the KASLR offset, the build ID of the kernel, and the OS release. With this information, a debugger could attach to a live GDB stub (e.g. kgdb, or QEMU) without needing to specify debuginfo file names or memory KASLR memory offsets. To that end, we hope to extend the GDB remote protocol with a facility that would allow the debugger to request this information. We've written up an idea for this proposal at [3]. The summary is: 'q linux.vmcoreinfo' Retrieves the Linux vmcoreinfo data. Reply: 'Q [DATA]' data is encoded as described in the Binary Data doc [4] 'E.' with an informative message if the data is not available However, with the candidate kgdb implementation taking shape [5], we're becoming concerned regarding this design. It seems that there is an implicit maximum packet size which is not described in the protocol documentation. Many stubs have small(ish) shared output buffers. It seems to me that data which would be 3k bytes before escaping is too large. We've noticed that there is a 'qXfer' query packet which allows specifying an offset and a number of bytes. Maybe it would be better for us to add a new 'special data area' for the 'qXfer' message, and reuse that command? To sum up, my specific questions are: 1. What is the maximum protocol packet size, if any? 2. Would this functionality be better implemented in a single "q linux.vmcoreinfo" packet, or as a "qXfer" packet? 3. Is it safe to assume that data transmitted in the qXfer packets is encoded via the escaped binary data format described at [4] (rather than the hexadecimal encoding)? Any other feedback is welcome too. Thanks, Stephen [1]: https://github.com/osandov/drgn [2]: https://docs.kernel.org/admin-guide/kdump/vmcoreinfo.html [3]: https://github.com/osandov/drgn/wiki/GDB-Remote-Protocol-proposal:-linux.vmcoreinfo-query-packet [4]: https://sourceware.org/gdb/current/onlinedocs/gdb.html/Overview.html#Binary-Data [5]: https://lore.kernel.org/linux-debuggers/20241210133448.3684593-1-tjarlama@gmail.com/T/#mad965a732c1c5e9e2656e4be79ffcdc36d89b7d1 [6]: https://sourceware.org/gdb/current/onlinedocs/gdb.html/General-Query-Packets.html#qXfer-read