From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from OS8PR02CU002.outbound.protection.outlook.com (mail-japanwestazon11012059.outbound.protection.outlook.com [40.107.75.59]) (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 BE8362AD16; Fri, 19 Sep 2025 13:00:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.75.59 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758286840; cv=fail; b=UZeifjNWQ8cqV04zzN/0rEjCRSOf+ADjsMAWeNWx9t2EkPLXo4zwxwtoqSu/iDc+26yxeYfTQGfauslTsVgDr4NexDS6yWtWY2tlKoDFCey4XQA7b+hV/RSoh79LcKemTcizEaA+8puWlMMHVahY7LEWWzcQ8ns3dqLeqlOA8v0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758286840; c=relaxed/simple; bh=nbICLxYsb07Nsg/g2T/4wwM4AZ8Jp/AxW2OPBbO1+h8=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=l5p24Jm24y2Lei6Jhz6LVPU3W/ueS3ATwR+mM4BC/SQIRn1//7rI6Kp5AOYTQMYlBlCCK6rV0Y2JUKvnlNJSEBYHkElony3zl+He8KAOi2VFb28jzYZfV4yFRPQcaTILYbGuZYrnAHQcs/16Coam/7vjvt00H/3dnyriWOqvUy4= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=vivo.com; spf=pass smtp.mailfrom=vivo.com; dkim=pass (2048-bit key) header.d=vivo.com header.i=@vivo.com header.b=az82Dd22; arc=fail smtp.client-ip=40.107.75.59 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=vivo.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=vivo.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=vivo.com header.i=@vivo.com header.b="az82Dd22" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=rrddnGM08nlwiPF3zLmqAYSi3+KmM6ES/9tQ/kg1lbHYs1N+h+DjDLjHjf7GKEtPGu6P06QqzbrBGyE1NwvqeMjTQw5z/Dmk3cvaIx91BJtNy4zgQjO9glwzQ88nXkfR5IwYzkVbuxUv0AfmTV1JIRqeIMQ0/1omfUbygLA9zCKhcsPdav3F+NvQhz5Xfpyd+PJtvIimHhgJUm702HEhI4y3VdHK5MueoV/No74K2pRTvavBufQ33ADi+rf9B4m31XvG3VROD+LMfTIRWUKjzFg4oiJPiBWNeskvcQBEoOYKCeDG95QYjwhZ7SuO7dKJMQ9RF7kCWja0b2b4YFju5A== 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=YcRmDNq6D0i2iIb8V9epm/MxX3Aqzx9heVLAUQJQEqc=; b=bjJyEE3hL71hsI1Y29YoQjiXpWvd1M4wcUSuDNtNF+2tXCB/RfXAQmHTuju7l2cTlROHla/IJI4uDJaVQejK0QZoLm5L65N7klWzVdN0pUmKbNFS7LnURhvPIu+mQSU1DWU0qGl3dD6iPGFqU5GkvHJV+fphPxJohjmf8fgQ34rJwUdQFV4zL4C5ppBzZeZwP7PA6nHqMHmzA3qKDJVwc+XaQNpEgC83UctcDuFVsGBxtyQO6EgCzIqyuOOrVYwTxsSUqnWuqZ2X7I9IeILvJck8p4lYgo2GMmMnSk1Mbvcv2MmgloNBcf7nyRv502y/M28q12sDbfQv5PssXYc4cg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=vivo.com; dmarc=pass action=none header.from=vivo.com; dkim=pass header.d=vivo.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=vivo.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=YcRmDNq6D0i2iIb8V9epm/MxX3Aqzx9heVLAUQJQEqc=; b=az82Dd22vv+yfOlmltWk/DZ5e3dJplNqe94v3keQaCyW4MT0cBsKGG0qgPjMCyioaQjK0alcaJppyIFp7LNfv+eHn7eKdDW/C9U+BVImWvZq/Xbg1xVU/q/jtLLLROXpJQGugsk7pDST0TANt8xOyda0kDqVy/mzfSX91aYUPoG/ZZXkn/bCL9LZP24ibkquGzNBSzXw4E+kobYFAGwHeH5avHWMBkKylj0jj+gbRoXo5ymLqrcghqJn5U5M+G09D7KTNUaXpyqgYHpkgtSe9u30IVPP9C/Q6Nc0zfnUvGYZ0zDlY0/dKkl6fqvXy2njMvhLfQXmhRgBV3HG9SCXZQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=vivo.com; Received: from PUZPR06MB4742.apcprd06.prod.outlook.com (2603:1096:301:b5::13) by SE2PPF6DE20C888.apcprd06.prod.outlook.com (2603:1096:108:1::7d6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9115.19; Fri, 19 Sep 2025 13:00:34 +0000 Received: from PUZPR06MB4742.apcprd06.prod.outlook.com ([fe80::206c:c661:9838:5571]) by PUZPR06MB4742.apcprd06.prod.outlook.com ([fe80::206c:c661:9838:5571%4]) with mapi id 15.20.9137.015; Fri, 19 Sep 2025 13:00:34 +0000 Message-ID: <787f5dff-7ac0-4193-a5c9-5eafa9a7b4e5@vivo.com> Date: Fri, 19 Sep 2025 21:00:27 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH bpf-next v1 0/3] bpf: Add BPF program type for overriding tracepoint probes To: Steven Rostedt Cc: Jiri Olsa , Song Liu , ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, yonghong.song@linux.dev, haoluo@google.com, eddyz87@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, shuah@kernel.org, willemb@google.com, kerneljasonxing@gmail.com, paul.chaignon@gmail.com, chen.dylane@linux.dev, memxor@gmail.com, martin.kelly@crowdstrike.com, ameryhung@gmail.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, yikai.lin@vivo.com References: <20250917072242.674528-1-zhaofuyu@vivo.com> <9cb5b3d5-97bb-4165-9a84-394d3d45a20e@vivo.com> <20250918113234.3f9e556a@gandalf.local.home> From: Fuyu Zhao In-Reply-To: <20250918113234.3f9e556a@gandalf.local.home> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SI1PR02CA0014.apcprd02.prod.outlook.com (2603:1096:4:1f7::9) To PUZPR06MB4742.apcprd06.prod.outlook.com (2603:1096:301:b5::13) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PUZPR06MB4742:EE_|SE2PPF6DE20C888:EE_ X-MS-Office365-Filtering-Correlation-Id: d0e93ec4-4418-43c0-3baf-08ddf77c8509 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?d29NbjRoUHBVTWlYQ29CdVBUSy94c3BtU0JON1VPVG82ZUdzckRndkpnMlUz?= =?utf-8?B?cnM5Q3J4UitjWWdyZDJzeDJFWmsxZ2hIVFh3dTZZcGpWaVNsb21oTFdrTHZR?= =?utf-8?B?SDZlYzlZM1JVME10RFg3Wjc5YjZ4N3gvd0ozTTk2UUNxTm1oZDl3cE9WenpG?= =?utf-8?B?cTcrdWJGY0V2dXR3alM4NndwV2tVb090ZWdvOTJ1bFlvTkZTYWxiUk1Dc2hP?= =?utf-8?B?M3pXWFZrVzBqc0dPMHRkbXRuREZSY3JRZ1l5bTQyQ1dXTVJCVEdKVHd0cDFO?= =?utf-8?B?UENsOXdvYXg0Sm50aWJad3hva1dUc01uM2N6T1VrQkl5NWFFUHc3R3JHbFBt?= =?utf-8?B?VHM5a2twUU0xc2taUWFydnE4THk4RGo0U2xieTZZcmJNWjAwVjlPQVAyL2hT?= =?utf-8?B?U0NReVVpbzVXR2svdFRHVlNJbGNKN21KRjVlemRpSFdteDBYS2NYUGlFWThJ?= =?utf-8?B?QlArTVFKU1JRTFdvYU5tK1hYb1BSb1BJSUZaZnhrTnV0cWVjaVE0UHMyRHlm?= =?utf-8?B?cFpVaUlSMlh6ck1iaTBhMUpsWUdDdGFobnRhenNSZmZhWnY4Ly81OFVFemxC?= =?utf-8?B?UXl5enNzNDNqWTBHN3FsU3RkejhkMTNxUFhVWXRWRk4raENJY2s1ZE9HWmZo?= =?utf-8?B?akRRbi9pbUZYMXM0SGltOXRJU05rcnBtOGpod29PWGFUOHJZMVNmS0hrT3U2?= =?utf-8?B?V2VWMWpPVWRwOGZ1WjlBNE5LK3VtS2oybG92Q0tDaVMzSVYzeXZ0cXlXYTZ0?= =?utf-8?B?UlRtbmp4YUFBSmhBeHRSd3owanZ2Yk9sczBVNHBOcXZWOGlOaVg2RHN3ZVoz?= =?utf-8?B?dW1CUFRUakNMMGVKckpQTTZ1Y3NndnR1WGpGKzVaVytZOFFXclZoZi9HYzcw?= =?utf-8?B?MVdkcXJCMVZDTEIrY3ZxWmJkb0VMSi9uSVZ3aTJPbU9La1QrWmtZWjA0dERv?= =?utf-8?B?bnBjVG1ZZDNpVmtuTU1UVUNoakNoczJYalJMRTFPNjZIS2x5eW5xaENXazlo?= =?utf-8?B?TEM2NWJ0aWJ0dEJBbHY4VTZJZjdhVTRDbVpqVTRQL1BESGdHTTZaSTZmU1k5?= =?utf-8?B?V2hSYXhoUlZMMVdrZEJ4Z1FrQk45dk5aeVNrVG9ZazYvcjd6eGJGMHhrY2J4?= =?utf-8?B?UmhZUjRya2t2M0tCUEhIWlJNVTZzb3JGY3Y1Z2VicmlYeklFekJ0UUxtaHFz?= =?utf-8?B?MWYrVnFqM1VnYU5PRnA4dWt3N2RWYkV3d1Z0M2p6aXRlaWlvWTdmeFZaZ1lu?= =?utf-8?B?aXdiZmJBL2hDVjllQWxWNXIwMmJMdXFLTGlCbFJGSjkrY0M0ejFvN1o4UHVX?= =?utf-8?B?ZHhnT0RkOHpLMlBnS2xpL2xCQWgvTXJ2emZIbGhhZTVrZkhxSzFTeEhqcUJr?= =?utf-8?B?WVp2dkVhQ1QzajN1RTlweEtxbk1Vemh5YlF0TWZhK1ZTRk16T1NDZm9YcGxL?= =?utf-8?B?L0pubHpSUEJnZWg0WEhKOVpNbk81cjFoNWt6UWpYUFVKOWxobDdZZHdpSkhY?= =?utf-8?B?TmFtTVRUNFlVV0wvMGtDR2lEOGM5YW5SNnU3MURya3VCQ29QQlpFSkorbFFj?= =?utf-8?B?eW94M2lpREhrTFhGVEQrUkw5czZweHhEdzFsMWI4azEvdnhtcmE0a1Y1VmJX?= =?utf-8?B?ejhMaTAyTWhXSmJwYUlqTkVLZWU3WlNnWG40ckJSdmkzb0xpVFNPQVhjVitz?= =?utf-8?B?cVZYbytZc0hoN1JwZWI0MlFuei9vdG9JWGVWbVZZNEViQ09KNUpYVmhiVjNq?= =?utf-8?B?NFR5aUMrZFFTSUhmV1hPRllQbm5JMmZSMWRyYTM2dm0zMERuL1A2amZNdnY2?= =?utf-8?B?YlR2U3pEemhzNEU5Sk5GeUhsMFVPb2hNUGlPVUQ4cjZrRTZabTh2SisxbGFG?= =?utf-8?B?Mm1KbE5uQzUzUVlRWGRYbzhIczhkUmdkSnlrNzkrZUoyck9RTzA0a1FHRTR4?= =?utf-8?Q?BzyQ6ZYTXmw=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PUZPR06MB4742.apcprd06.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?dFd1OTNxRHJ1YmhDOXhxZU1kU3RKc3JXK09TR2RBbTJ5ODVlUjFidE8zNjcr?= =?utf-8?B?S280dDJpWHZYTy9IV2c4Y2R4WkpIcit5M0t2M3JzN3VmL1BEUEpSVWpPR3du?= =?utf-8?B?bU1yZVcyQkpQd0JnTGIzY1oxUE0zMFlGRVErUWl4ZDBnaFQxa0ZVSytFdWd6?= =?utf-8?B?UXFBRU9UU0NoellLdHlOQmFnWGZRTUxIMnJqL0U4Q2Q1ZWxBVDl6cGhleW9u?= =?utf-8?B?UStwcjNXWGhkV0ZtV0RON051YXFHY3hEejBaS2p6bkY1cW1lMXo2aW9WQ1U0?= =?utf-8?B?WlgzcWRyRmtXT3o5Z0pya1NPb2pWbnZpUjJzbkVWS1krWm8xN3RURWFWanVF?= =?utf-8?B?a0t5dXV2YVNlSnN3STNsN0ZkNG1aTU1pUndFM0VGRXZxeVE1eWRBUmMrN2tu?= =?utf-8?B?OWxZTlVkSG9uVVpIUEx5VU9IZGdtQ1hjUWJ3QmhBODdmMWYvOFZiUmR0U1p1?= =?utf-8?B?QlpGQUE1SmhGNnpSTUcxeU1RQ080RlByS3FBZ2ppYVhONzg2UjFMNkNpcXE5?= =?utf-8?B?TlFtSjh3MkFnM1FvRHQ3cmF3RllkcnR6Y1pNa0lxdjVRbkZ1NmlHQ2l3ZmRn?= =?utf-8?B?anVSMEVqUUd1elBCWFYwbTgwanlIUnhkcHNRcjNMU2RwNXdVQWRXaGJlM1Q4?= =?utf-8?B?SzZOMkt4RmFsaHNqcGxQakdpREVyQTBSUENBM0VGN2kwc3A5dUx2YldNbjRm?= =?utf-8?B?bitrZlhmQkRBZUdkTW8vbHRuVHY3Q3g0cENaZWtoYjVteDUxUWUxY3RmeTA4?= =?utf-8?B?czRzcmN0OTIwaGxpUlNyTHJMeXpZWk04MUl2VWxWY1dGNHdEZEl0TmQ4SmV6?= =?utf-8?B?Q3BWaFpaMDN5NmxXK2lMTTIrS3ZBbGM1eVhmMlBvcnJVL09CdmQ3OExrWFVq?= =?utf-8?B?eG1SSkJVam1XRG1abTNDcVFIdHZ3L3pmenhyY1VtNHJYVHFpejYrSmpzRVZV?= =?utf-8?B?aWwvRWF4VVhPWUlmWDFnOXcrQ2R2YktvSG9oTmM4bUoxS1FqQ3J0cWZncHY5?= =?utf-8?B?K3hjMXMrQ1N4MW8rbVVrWFg2Zmp6YzYyL0U0bFVrTFYxdTlmN1p4TXRWSi9Q?= =?utf-8?B?T2QxS09Oc3VEdlBMN3QwVWkydTFRYnRUYUt1UXpHaExYUGFQV21lNlg2UVpK?= =?utf-8?B?MkxoL05YSm1PcFJIWG1DZmhGL3RSVjk5V29BSC9URjR5RXFtRGN4ZW40VGpl?= =?utf-8?B?ZjF4Y1A2b1NrZkoxN3VDTjc5SUxJa0E0SHVXK3hIejIxcG50azF5RUdVV1ZR?= =?utf-8?B?YjdkaGlNcnVWYVlDUnRTTUtQWDNpZ2FGc2VHWW1JN2EwZk9NN3VOUm9Xb0xp?= =?utf-8?B?UEltWEcwTitJZkwzMkQrNjN4S1NBclFqSHpheVNPMisxTmc4cTlRVW8rRE83?= =?utf-8?B?aVBnaElyR21tN0x1Z01JKzlod3ZZYWh5cFdpT2M4ODRwNjlPQzJJUnRoMll3?= =?utf-8?B?WGpubkFDenJaR244YnVFZFZFZE5xT3Nha2Yra3Q3UWxYRzV3U0hlUWpNckgz?= =?utf-8?B?aHNseElGSVZpdnZwWHhJZjZmSGY1TnR1VEp0azVlNEZXY1psTVRkdHk5aXFD?= =?utf-8?B?RGt0NFFKekhSbUcvRWNQNlRMN245TlJBTWNRbUhmVDdkTE9tb09zWDhVUWhN?= =?utf-8?B?cmQxL2FtZmZsc0dNN2NMNGVUWDJpeWRwN0xERUErVDFHYUJZWkZLVzNIRSto?= =?utf-8?B?WU5XcDlYNkRWNlNuYTZlUFlPUmQ1K2tZZ3FmMFJxTTdhOVp6ZTM0dUNLM0dx?= =?utf-8?B?cFZzNm1TU0JUVHlDMU14RE80NXZ0WERxVys3QThlSnBoQkgvQk44Zk5YTWxs?= =?utf-8?B?WVVKWmNYcDZJYk5PMGxkTHUxcTJJOEhQdkFhVGdKOUxreHZPQUNxd1pNeElL?= =?utf-8?B?UUJOQUl1RjQ5Nm5qdVhVOE1waUs4QmN5VVpzMnhQNVNlVjI0MHA0aDIvWG9X?= =?utf-8?B?MzcyUFNCNVBiQkpOYktmc0hLcFVGVDZFV3BmT3pKM2MzNmFHNjRadjMvWTB2?= =?utf-8?B?cjZESmc4S2hldWZ2NzFsUDNOMVFzc1Z5UGJMUHFrU1F0ZE5aRXlnRFhHZEpB?= =?utf-8?B?QTZQeXF5RkJOZFhzTmcycTVpNnAvNndjeEY4TEg4VDFkOGRuMEkwTHVENnk4?= =?utf-8?Q?nQ5ryE9ia+WDT4zl9m97SSIkg?= X-OriginatorOrg: vivo.com X-MS-Exchange-CrossTenant-Network-Message-Id: d0e93ec4-4418-43c0-3baf-08ddf77c8509 X-MS-Exchange-CrossTenant-AuthSource: PUZPR06MB4742.apcprd06.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Sep 2025 13:00:33.8535 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 923e42dc-48d5-4cbe-b582-1a797a6412ed X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: wVasHYJWu95iaWaPNN1jqfhjsCmN9BMYuDgrWF+NVr7XKxSTLPb1TgqsrhLNpHp6E2SwQJZBk+OqoGnJsWBkaA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SE2PPF6DE20C888 On 9/18/2025 11:32 PM, Steven Rostedt wrote: > On Thu, 18 Sep 2025 21:15:57 +0800 > Fuyu Zhao wrote: > >> As for the reason not to unregister and register a new callback: >> callbacks registered directly inside the kernel cannot be unregistered from >> user space. From user space, we can only attach additional callbacks >> with BPF programs, but can not remove or replace the ones already >> registered in the kernel. Therefore, an override mechanism is needed. > > The fact that user space cannot unregister or override the current > callbacks, to me is a feature and not a bug. > > -- Steve I see, thank you for sharing your view — I’ll keep it in mind. Sincerely, Fuyu