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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 B5019C2BB86 for ; Tue, 14 Apr 2020 02:16:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93EF62072D for ; Tue, 14 Apr 2020 02:16:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404056AbgDNCQM (ORCPT ); Mon, 13 Apr 2020 22:16:12 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:42909 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404055AbgDNCQI (ORCPT ); Mon, 13 Apr 2020 22:16:08 -0400 X-Originating-IP: 50.39.163.217 Received: from localhost (50-39-163-217.bvtn.or.frontiernet.net [50.39.163.217]) (Authenticated sender: josh@joshtriplett.org) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 8FC94240002; Tue, 14 Apr 2020 02:16:03 +0000 (UTC) Date: Mon, 13 Apr 2020 19:16:01 -0700 From: Josh Triplett To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, linux-arch@vger.kernel.org Cc: Alexander Viro , Arnd Bergmann , Jens Axboe , Aleksa Sarai Subject: [PATCH v4 3/3] fs: pipe2: Support O_SPECIFIC_FD Message-ID: <2993aae005b70f51636553d1522baa063ea01a26.1586830316.git.josh@joshtriplett.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org This allows the caller of pipe2 to specify one or both file descriptors rather than having them automatically use the lowest available file descriptor. The caller can specify either file descriptor as -1 to allow that file descriptor to use the lowest available. Signed-off-by: Josh Triplett --- fs/pipe.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 16fb72e9abf7..4681a0d1d587 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -936,19 +936,19 @@ static int __do_pipe_flags(int *fd, struct file **files, int flags) int error; int fdw, fdr; - if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT)) + if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT | O_SPECIFIC_FD)) return -EINVAL; error = create_pipe_files(files, flags); if (error) return error; - error = get_unused_fd_flags(flags); + error = get_specific_unused_fd_flags(fd[0], flags); if (error < 0) goto err_read_pipe; fdr = error; - error = get_unused_fd_flags(flags); + error = get_specific_unused_fd_flags(fd[1], flags); if (error < 0) goto err_fdr; fdw = error; @@ -969,7 +969,11 @@ static int __do_pipe_flags(int *fd, struct file **files, int flags) int do_pipe_flags(int *fd, int flags) { struct file *files[2]; - int error = __do_pipe_flags(fd, files, flags); + int error; + + if (flags & O_SPECIFIC_FD) + return -EINVAL; + error = __do_pipe_flags(fd, files, flags); if (!error) { fd_install(fd[0], files[0]); fd_install(fd[1], files[1]); @@ -987,6 +991,10 @@ static int do_pipe2(int __user *fildes, int flags) int fd[2]; int error; + if (flags & O_SPECIFIC_FD) + if (copy_from_user(fd, fildes, sizeof(fd))) + return -EFAULT; + error = __do_pipe_flags(fd, files, flags); if (!error) { if (unlikely(copy_to_user(fildes, fd, sizeof(fd)))) { -- 2.26.0