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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham 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 3EA8DC38A30 for ; Wed, 22 Apr 2020 05:20:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1858B206D4 for ; Wed, 22 Apr 2020 05:20:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726033AbgDVFUa (ORCPT ); Wed, 22 Apr 2020 01:20:30 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:48245 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725787AbgDVFUa (ORCPT ); Wed, 22 Apr 2020 01:20:30 -0400 Received: from localhost (50-39-163-217.bvtn.or.frontiernet.net [50.39.163.217]) (Authenticated sender: josh@joshtriplett.org) by relay11.mail.gandi.net (Postfix) with ESMTPSA id D539D100004; Wed, 22 Apr 2020 05:20:23 +0000 (UTC) Date: Tue, 21 Apr 2020 22:20:20 -0700 From: Josh Triplett To: io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, mtk.manpages@gmail.com Cc: Alexander Viro , Arnd Bergmann , Jens Axboe , Aleksa Sarai , linux-man@vger.kernel.org Subject: [PATCH v5 3/3] fs: pipe2: Support O_SPECIFIC_FD Message-ID: <2bb2e92c688b97247f644fe8220054d6c6b66b65.1587531463.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)))) { -- 2.26.2