From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD76CC433EA for ; Mon, 17 Aug 2020 22:10:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D19C2063A for ; Mon, 17 Aug 2020 22:10:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730167AbgHQWKL (ORCPT ); Mon, 17 Aug 2020 18:10:11 -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=20P=2E=20Berrang=C3=A9?= , 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 Content-Transfer-Encoding: 8bit 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 Subject: [PATCH 06/17] file: Implement fcheck_task 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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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" --- 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; -- 2.25.0