From patchwork Mon Aug 17 22:04:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 1346526 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=xmission.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BVpCG41dsz9sR4 for ; Tue, 18 Aug 2020 08:10:50 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730141AbgHQWKD (ORCPT ); Mon, 17 Aug 2020 18:10:03 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:32968 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730094AbgHQWJ5 (ORCPT ); Mon, 17 Aug 2020 18:09:57 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out03.mta.xmission.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1k7nKF-001Gya-MY; Mon, 17 Aug 2020 16:09:55 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.int.ebiederm.org) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1k7nKE-0004PB-TN; Mon, 17 Aug 2020 16:09:55 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, criu@openvz.org, bpf@vger.kernel.org, Linus Torvalds , Alexander Viro , Christian Brauner , Oleg Nesterov , Cyrill Gorcunov , Jann Horn , Kees Cook , =?utf-8?q?Daniel_P=2E_Berrang?= =?utf-8?b?w6k=?= , Jeff Layton , Miklos Szeredi , Matthew Wilcox , "J. Bruce Fields" , Matthew Wilcox , Trond Myklebust , Chris Wright , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , "Eric W. Biederman" Date: Mon, 17 Aug 2020 17:04:14 -0500 Message-Id: <20200817220425.9389-6-ebiederm@xmission.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <87ft8l6ic3.fsf@x220.int.ebiederm.org> References: <87ft8l6ic3.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1k7nKE-0004PB-TN; ; ; mid=<20200817220425.9389-6-ebiederm@xmission.com>; ; ; hst=in02.mta.xmission.com; ; ; ip=68.227.160.95; ; ; frm=ebiederm@xmission.com; ; ; spf=neutral X-XM-AID: U2FsdGVkX18+FAvHqoU00EuPv+eIsuw9qOJOke3CL9M= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa07.xmission.com X-Spam-Level: * X-Spam-Status: No, score=1.3 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TooManySym_01,XMNoVowels autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * 1.5 XMNoVowels Alpha-numberic number with no vowels * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 0; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: ; sa07 0; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *;linux-kernel@vger.kernel.org X-Spam-Relay-Country: X-Spam-Timing: total 366 ms - load_scoreonly_sql: 0.04 (0.0%), signal_user_changed: 12 (3.4%), b_tie_ro: 11 (3.0%), parse: 1.42 (0.4%), extract_message_metadata: 13 (3.6%), get_uri_detail_list: 1.29 (0.4%), tests_pri_-1000: 15 (4.1%), tests_pri_-950: 1.19 (0.3%), tests_pri_-900: 1.05 (0.3%), tests_pri_-90: 120 (32.8%), check_bayes: 118 (32.3%), b_tokenize: 8 (2.3%), b_tok_get_all: 7 (1.8%), b_comp_prob: 2.3 (0.6%), b_tok_touch_all: 97 (26.5%), b_finish: 1.04 (0.3%), tests_pri_0: 188 (51.3%), check_dkim_signature: 0.87 (0.2%), check_dkim_adsp: 2.0 (0.6%), poll_dns_idle: 0.42 (0.1%), tests_pri_10: 2.9 (0.8%), tests_pri_500: 8 (2.3%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 06/17] file: Implement fcheck_task X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org As a companion to fget_task implement fcheck_task for use for querying a process about a specific file. Signed-off-by: "Eric W. Biederman" Acked-by: Christian Brauner --- fs/file.c | 13 +++++++++++++ include/linux/fdtable.h | 1 + 2 files changed, 14 insertions(+) diff --git a/fs/file.c b/fs/file.c index c585dbaf31a3..8d4b385055e9 100644 --- a/fs/file.c +++ b/fs/file.c @@ -863,6 +863,19 @@ struct file *fget_task(struct task_struct *task, unsigned int fd) return file; } +struct file *fcheck_task(struct task_struct *task, unsigned int fd) +{ + /* Must be called with rcu_read_lock held */ + struct file *file = NULL; + + task_lock(task); + if (task->files) + file = fcheck_files(task->files, fd); + task_unlock(task); + + return file; +} + /* * Lightweight file lookup - no refcnt increment if fd table isn't shared. * diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 7cc9885044d9..def9debd2ce2 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -103,6 +103,7 @@ static inline struct file *fcheck_files(struct files_struct *files, unsigned int * Check whether the specified fd has an open file. */ #define fcheck(fd) fcheck_files(current->files, fd) +struct file *fcheck_task(struct task_struct *task, unsigned int fd); struct task_struct;