From patchwork Fri Nov 20 23:14:30 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: 11922879 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 89271C56202 for ; Fri, 20 Nov 2020 23:20:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50C1922470 for ; Fri, 20 Nov 2020 23:20:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729335AbgKTXUV (ORCPT ); Fri, 20 Nov 2020 18:20:21 -0500 Received: from out02.mta.xmission.com ([166.70.13.232]:46984 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729241AbgKTXUA (ORCPT ); Fri, 20 Nov 2020 18:20:00 -0500 Received: from in02.mta.xmission.com ([166.70.13.52]) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1kgFh8-002RbD-NX; Fri, 20 Nov 2020 16:19:58 -0700 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 (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1kgFdy-00EG00-Lx; Fri, 20 Nov 2020 16:16:43 -0700 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?Da?= =?utf-8?q?niel_P_=2E_Berrang=C3=A9?= , Jeff Layton , Miklos Szeredi , Matthew Wilcox , "J. Bruce Fields" , 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: Fri, 20 Nov 2020 17:14:30 -0600 Message-Id: <20201120231441.29911-13-ebiederm@xmission.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <87r1on1v62.fsf@x220.int.ebiederm.org> References: <87r1on1v62.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1kgFdy-00EG00-Lx;;;mid=<20201120231441.29911-13-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX194cx44q+KvkyQRjsxLSGAq1iGzNebFjbg= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 13/24] kcmp: In get_file_raw_ptr use task_lookup_fd_rcu X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Modify get_file_raw_ptr to use task_lookup_fd_rcu. The helper task_lookup_fd_rcu does the work of taking the task lock and verifying that task->files != NULL and then calls files_lookup_fd_rcu. So let use the helper to make a simpler implementation of get_file_raw_ptr. Signed-off-by: "Eric W. Biederman" Acked-by: Cyrill Gorcunov --- kernel/kcmp.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/kernel/kcmp.c b/kernel/kcmp.c index 990717c1aed3..36e58eb5a11d 100644 --- a/kernel/kcmp.c +++ b/kernel/kcmp.c @@ -61,16 +61,11 @@ static int kcmp_ptr(void *v1, void *v2, enum kcmp_type type) static struct file * get_file_raw_ptr(struct task_struct *task, unsigned int idx) { - struct file *file = NULL; + struct file *file; - task_lock(task); rcu_read_lock(); - - if (task->files) - file = files_lookup_fd_rcu(task->files, idx); - + file = task_lookup_fd_rcu(task, idx); rcu_read_unlock(); - task_unlock(task); return file; }