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=-17.0 required=3.0 tests=BAYES_00,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 58191C83012 for ; Thu, 3 Dec 2020 13:32:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27E5A206CA for ; Thu, 3 Dec 2020 13:32:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436928AbgLCNbR (ORCPT ); Thu, 3 Dec 2020 08:31:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:48816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2436888AbgLCNbL (ORCPT ); Thu, 3 Dec 2020 08:31:11 -0500 From: Sasha Levin Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jens Axboe , Jakub Kicinski , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 08/14] tun: honor IOCB_NOWAIT flag Date: Thu, 3 Dec 2020 08:30:04 -0500 Message-Id: <20201203133010.931600-8-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201203133010.931600-1-sashal@kernel.org> References: <20201203133010.931600-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jens Axboe [ Upstream commit 5aac0390a63b8718237a61dd0d24a29201d1c94a ] tun only checks the file O_NONBLOCK flag, but it should also be checking the iocb IOCB_NOWAIT flag. Any fops using ->read/write_iter() should check both, otherwise it breaks users that correctly expect O_NONBLOCK semantics if IOCB_NOWAIT is set. Signed-off-by: Jens Axboe Link: https://lore.kernel.org/r/e9451860-96cc-c7c7-47b8-fe42cadd5f4c@kernel.dk Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/tun.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index d84a09172ddbf..fe0e02e11f294 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1988,12 +1988,15 @@ static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from) struct tun_file *tfile = file->private_data; struct tun_struct *tun = tun_get(tfile); ssize_t result; + int noblock = 0; if (!tun) return -EBADFD; - result = tun_get_user(tun, tfile, NULL, from, - file->f_flags & O_NONBLOCK, false); + if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) + noblock = 1; + + result = tun_get_user(tun, tfile, NULL, from, noblock, false); tun_put(tun); return result; @@ -2214,10 +2217,15 @@ static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) struct tun_file *tfile = file->private_data; struct tun_struct *tun = tun_get(tfile); ssize_t len = iov_iter_count(to), ret; + int noblock = 0; if (!tun) return -EBADFD; - ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL); + + if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) + noblock = 1; + + ret = tun_do_read(tun, tfile, to, noblock, NULL); ret = min_t(ssize_t, ret, len); if (ret > 0) iocb->ki_pos = ret; -- 2.27.0