From patchwork Thu Oct 10 18:15:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Stoakes X-Patchwork-Id: 13830651 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41A07CFC5EC for ; Thu, 10 Oct 2024 18:16:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B9CFE6B0089; Thu, 10 Oct 2024 14:16:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B25016B008A; Thu, 10 Oct 2024 14:16:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 977676B008C; Thu, 10 Oct 2024 14:16:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 6F9A86B0089 for ; Thu, 10 Oct 2024 14:16:03 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 977FEAC447 for ; Thu, 10 Oct 2024 18:15:55 +0000 (UTC) X-FDA: 82658496564.21.9598CC3 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf22.hostedemail.com (Postfix) with ESMTP id 1A27AC0019 for ; Thu, 10 Oct 2024 18:15:57 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=NKHWinVB; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=mOB7l7Js; dmarc=pass (policy=reject) header.from=oracle.com; spf=pass (imf22.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1728584008; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references:dkim-signature; bh=Hz0h0h0XOOiy1O+X+Llq/CysKHWSSxoQM8TyPcQQTys=; b=bX5yLAJBxm/dFYoNWY87EMlIiqb6HMf7ePLq8aFedSI1iR0SMonOmTJ3KAHDQGA6YyI4DG f3BEVnOFIkdV9fZOCgDHRdDMBmvDcdD3gq1byb+40VSoTZB/4N7CU6JVYCi1FpJjIMPvWX QUraC8HjJ2Mcnx8aPYyThqgJxz8qz0k= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1728584008; a=rsa-sha256; cv=pass; b=hw0zxwtDjKgmKsCW4/NwLBUWcHoD40y9EN6ci5dKfZ4XHoy3X2nGI1PGLLJS7/RJDtMmiY z0+z1SxWG58fa0VunmCx1PtTyGVVCZZY2up4+TQrP6lzEX+z5b0Pe+XXVTT1OLxOR0rReW LlVzO/L5iGKiJ4xgM9gk7a9n9sB/LSE= ARC-Authentication-Results: i=2; imf22.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=NKHWinVB; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=mOB7l7Js; dmarc=pass (policy=reject) header.from=oracle.com; spf=pass (imf22.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") Received: from pps.filterd (m0246629.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49AHteVf013553; Thu, 10 Oct 2024 18:15:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:content-type:date:from:message-id :mime-version:subject:to; s=corp-2023-11-20; bh=Hz0h0h0XOOiy1O+X +Llq/CysKHWSSxoQM8TyPcQQTys=; b=NKHWinVBjba/HY/1azklEY60Mw+KCeg9 BndjCdAO+JVF2yLHaMh0a6i0aJcoWdC0Ty0dU76DvfuUbp//6Ml2/+cIyquv1KzP 8+keaSrr/a2lkoXOwz3BvrNGfzXkkb4s5lTWWxwX333NFhj5PJxWFFd46ozzoBkN zUK7vLSRIKjnSJNvfaJVYCB7eAyqpNItk2eNqh/l2y21wQMI+41ZkTF7xNJN275c jy9JoTqW2qdaatFDdUqz3Ftmd+yFqAtiEr+oBD1568shAnxMXPBhSuLUi8uoWQWi iyBQQFrcq8rdFfc7sMuJAHGZlOtcr3ONH2Twy0gRVxm+js6TrEnbLA== Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.appoci.oracle.com [147.154.114.232]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 42302pk8nj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Oct 2024 18:15:51 +0000 (GMT) Received: from pps.filterd (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 49AHKAae027678; Thu, 10 Oct 2024 18:15:51 GMT Received: from nam10-mw2-obe.outbound.protection.outlook.com (mail-mw2nam10lp2043.outbound.protection.outlook.com [104.47.55.43]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 422uwaecea-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Oct 2024 18:15:51 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=pxnmlgVT/IWdRq4gP+ksC+Ll/frGzW1Fk/tinHIRAsOGKC3lc7Z+YFZ9Kvia6mL2bRVzuP5OexSQKz22RgvCSiZYAzdiJhybGrY/stWrKfV6IcI2ZGffk3VmjZLZCuGHfHtak0bh/kPTMxP46dnULhHdEyoInjZwISEovumpUaHKF1w9iAjm3IkBZ25z1tmZvPAaRwGCytgN0gY6CbkXeGvks8IpunpuFTrKwStvFyTiU5nYg1YIxiRA9JfsD6gCo6DC6YDd9ARxEPjVOSg5Vo/bRn3FalyRlhLtovx5eeb8suyCJigexY9MbNPNHEySjF/RK5C/dniO3HbktPswGQ== 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=Hz0h0h0XOOiy1O+X+Llq/CysKHWSSxoQM8TyPcQQTys=; b=xcc7jSVP4J4c1fJqYN7PcaGGutmT4TfVHrsJeT+LlvhDK8oOTh674epFc9CQufDRprya/aQI9IBMCeXINY6+KXC7R/GP2EvyLepvPW4ecyFMp8bQeBkKvIAHeW2qSzt8YdSaDWmGoiDCHnSG27jOlu408txF9b7LJmxPh2nYKWNWGHHWbgoVAAIJNuKGBITBRU8zGYVchJp8ArkJVB2MYWbm4mTxm16hNvc+U8PxO3D5CeEed4pNBr8dz5ZiAZZyQQeFhGITUg4BfAZw2eqMx9/d6t7TxCfrcpcKLET+9zt5PItWR6DvVtl70E8w0jd4acOdgAiFHvrfykXTZFc3ww== 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=Hz0h0h0XOOiy1O+X+Llq/CysKHWSSxoQM8TyPcQQTys=; b=mOB7l7Jsf2LFQo46cpX56JFjDEyhwB3WkcGDjSjbJq/IdL6bRmF8PdHVljKU+8vJNU9Mpb6EQwMRdqyOZFyuhnx3ESORuCO/15Q+0EjgU+wMRHaHyJZZkjjW19VEMULWulKLeF/6OTfFGSUoNgvijrmn4c+IlfX0EJy2w+2RiQU= Received: from SJ0PR10MB5613.namprd10.prod.outlook.com (2603:10b6:a03:3d0::5) by SJ2PR10MB7826.namprd10.prod.outlook.com (2603:10b6:a03:56b::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8048.18; Thu, 10 Oct 2024 18:15:48 +0000 Received: from SJ0PR10MB5613.namprd10.prod.outlook.com ([fe80::4239:cf6f:9caa:940e]) by SJ0PR10MB5613.namprd10.prod.outlook.com ([fe80::4239:cf6f:9caa:940e%5]) with mapi id 15.20.8048.017; Thu, 10 Oct 2024 18:15:48 +0000 From: Lorenzo Stoakes To: Christian Brauner Cc: Shuah Khan , "Liam R . Howlett" , Suren Baghdasaryan , Vlastimil Babka , pedro.falcato@gmail.com, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/3] introduce PIDFD_SELF* sentinels Date: Thu, 10 Oct 2024 19:15:42 +0100 Message-ID: X-Mailer: git-send-email 2.46.2 X-ClientProxiedBy: LO3P265CA0015.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:bb::20) To SJ0PR10MB5613.namprd10.prod.outlook.com (2603:10b6:a03:3d0::5) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR10MB5613:EE_|SJ2PR10MB7826:EE_ X-MS-Office365-Filtering-Correlation-Id: 3ba669a4-8a28-4e3b-03c8-08dce9579127 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016; X-Microsoft-Antispam-Message-Info: kliIaetPpahc676KFbtk7vnN73N0UAowfjDnXE0ZdOrOHK+7ZWizTnjFC2mVgzZawm47BsJAhW3VXVmVxHUqpEkajeNvtytQzjcnPzgfov23/2a3vDzWelw9sDrYnHifRR254XQLjC7N2t8O45UWQBxvTviE2dagTPcLhk7oIuNtVopXWaBkjQdUDNJ85d4JRqI2EydhOSlen9k3MsP7XZLihxosyQgdM+j5O1EfkswMHFv2WhUF62ELRc0wJU3oChl31l/7k5MJMqQ7sNJbz9QvcyZ7lcG4ChasKWuRyNKeBLmQlUWInj68V6OH5UsQq5ZZt7ORSwS2Fp7HGOvtezZv3RFNt0W7e3cRHFeu+bjEb59G/Rf9L8y4rXgCOb6p8CHwtHXV4gAN0vD6hCsNPla5TX3CKUV6UnDK7BLC3Apz78m/9jsP33pjgmZp4Cdby5Jq70Yp2x9LDshgaEi4N4jms6CZaARUk/2q6M2oqifTZlTMVvninfUqkwK6I3HZAb+9cBuhlt8F4fCF3w3fvICMBm7vYDpBBvoxnmKnL6T6eOMfiC7ZnxVrGQ3MmNx6epC9ymqwUfj5y3ICtOw0bMTPJ+boNoOhav4wy6enr+FE1MdwpTjjurFnVlBCElHrAtjJ7HDgwaaCrtDh13UGwt/JstSN6whN6Og+XnBHK82yqx8tTGozp79h6O6SjOCc+TiIkWfWoHCA+slzi8SN7LrVds0ch4BmRDGv4KgMj4crPAVkYZrUiu9eqfjIeIfd2sOZZ9W6GzE9XBVfYaj6w+1SQ3RcERcVgnkLw7BAcjbYKd8L0WDTPs/0xq2ZZl5/oEGrb20Dgl6lH9qcWrG9Pm782juYf66mq0mdPpbCsqFDVyH1av/ig9UWFf7mfCbUlJiBNM2d8r2fp0v7orRxzZZjyMzcaz5OHt7VpPomZFcisL4NmwAQjfEaszS0xSWW/lEh48Xn+j3TMQVf3NZRk8t69dZYJpnGzTk3Roxdt5O17w6WK8taetsuSja5LaHpK0eW20Egev7Fi2+ogGNAy1C0aOMmsIrZI4D6o5Wc83EyWyMUgeBV8QN45uu8kkqbBowgepGzpBtfRoWbkdm/6UFZv5lbKb1j4WhbdQkHxUbncbuwFZ6g4p44mzAgYOZnMppdjA2KSbeJOLAfXckz6vXM+WfWkjv4NHqEXysM2fzylrYQxYAs6zR5lN/X7mfBf684Utwp6EjCWGL1+TGS5Eg1eAXTz/JSWiIFmP1NeTajzB/cVQCclZNV7Nu8rHAGLD18x29HLbTuSNtAFVOlmA== X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SJ0PR10MB5613.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 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: 3ba669a4-8a28-4e3b-03c8-08dce9579127 X-MS-Exchange-CrossTenant-AuthSource: SJ0PR10MB5613.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Oct 2024 18:15:48.7634 (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: y/HYwNMW6KWjw/T9EVOJ76SNn51kNNFCAeQiB0uHGexWJLyiqQyWdYtF3QTxzPiLX6utYnXKcsT8iqQl6vrZ1ApyC03mJQtzchbTR6qsWuA= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR10MB7826 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-10_13,2024-10-10_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 malwarescore=0 mlxlogscore=999 mlxscore=0 suspectscore=0 adultscore=0 phishscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2409260000 definitions=main-2410100120 X-Proofpoint-ORIG-GUID: -9BnUN349CMi41VV344tZ1bCFdZMGunI X-Proofpoint-GUID: -9BnUN349CMi41VV344tZ1bCFdZMGunI X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 1A27AC0019 X-Stat-Signature: fpgpnguhq6u4oyzzc1cjzrxotie4qcc6 X-Rspam-User: X-HE-Tag: 1728584157-615194 X-HE-Meta: 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 rwcfBENp 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: If you wish to utilise a pidfd interface to refer to the current process or thread it is rather cumbersome, requiring something like: int pidfd = pidfd_open(getpid(), 0 or PIDFD_THREAD); ... close(pidfd); Or the equivalent call opening /proc/self. It is more convenient to use a sentinel value to indicate to an interface that accepts a pidfd that we simply wish to refer to the current process thread. This series introduces sentinels for this purposes which can be passed as the pidfd in this instance rather than having to establish a dummy fd for this purpose. It is useful to refer to both the current thread from the userland's perspective for which we use PIDFD_SELF, and the current process from the userland's perspective, for which we use PIDFD_SELF_PROCESS. There is unfortunately some confusion between the kernel and userland as to what constitutes a process - a thread from the userland perspective is a process in userland, and a userland process is a thread group (more specifically the thread group leader from the kernel perspective). We therefore alias things thusly: * PIDFD_SELF_THREAD aliased by PIDFD_SELF - use PIDTYPE_PID. * PIDFD_SELF_THREAD_GROUP alised by PIDFD_SELF_PROCESS - use PIDTYPE_TGID. In all of the kernel code we refer to PIDFD_SELF_THREAD and PIDFD_SELF_THREAD_GROUP. However we expect users to use PIDFD_SELF and PIDFD_SELF_PROCESS. This matters for cases where, for instance, a user unshare()'s FDs or does thread-specific signal handling and where the user would be hugely confused if the FDs referenced or signal processed referred to the thread group leader rather than the individual thread. We ensure that pidfd_send_signal() and pidfd_getfd() work correctly, and assert as much in selftests. All other interfaces except setns() will work implicitly with this new interface, however it doesn't make sense to test waitid(P_PIDFD, ...) as waiting on ourselves is a blocking operation. In the case of setns() we explicitly disallow use of PIDFD_SELF* as it doesn't make sense to obtain the namespaces of our own process, and it would require work to implement this functionality there that would be of no use. We also do not provide the ability to utilise PIDFD_SELF* in ordinary fd operations such as open() or poll(), as this would require extensive work and be of no real use. Non-RFC v1: * Removed RFC tag - there seems to be general consensus that this change is a good idea, but perhaps some debate to be had on implementation. It seems sensible then to move forward with the RFC flag removed. * Introduced PIDFD_SELF_THREAD, PIDFD_SELF_THREAD_GROUP and their aliases PIDFD_SELF and PIDFD_SELF_PROCESS respectively. * Updated testing accordingly. RFC version: https://lore.kernel.org/linux-mm/1d19f18c-5a60-44b5-a96f-9d0e74f2b02c@lucifer.local/ Lorenzo Stoakes (3): pidfd: extend pidfd_get_pid() and de-duplicate pid lookup pidfd: add PIDFD_SELF_* sentinels to refer to own thread/process selftests: pidfd: add tests for PIDFD_SELF_* include/linux/pid.h | 43 +++++- include/uapi/linux/pidfd.h | 15 ++ kernel/exit.c | 3 +- kernel/nsproxy.c | 1 + kernel/pid.c | 73 +++++++--- kernel/signal.c | 22 +-- tools/testing/selftests/pidfd/pidfd.h | 8 ++ .../selftests/pidfd/pidfd_getfd_test.c | 136 ++++++++++++++++++ .../selftests/pidfd/pidfd_setns_test.c | 11 ++ tools/testing/selftests/pidfd/pidfd_test.c | 67 +++++++-- 10 files changed, 330 insertions(+), 49 deletions(-) --- 2.46.2