From patchwork Fri Nov 20 14:59:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 329721 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=-15.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 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 9B6ECC63777 for ; Fri, 20 Nov 2020 15:00:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A2B82240B for ; Fri, 20 Nov 2020 15:00:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="DyvMpBgH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727839AbgKTO76 (ORCPT ); Fri, 20 Nov 2020 09:59:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727801AbgKTO76 (ORCPT ); Fri, 20 Nov 2020 09:59:58 -0500 Received: from mail-io1-xd44.google.com (mail-io1-xd44.google.com [IPv6:2607:f8b0:4864:20::d44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2431C0613CF for ; Fri, 20 Nov 2020 06:59:56 -0800 (PST) Received: by mail-io1-xd44.google.com with SMTP id d17so10202237ion.4 for ; Fri, 20 Nov 2020 06:59:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=to:cc:from:subject:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=0ev+vtzonlnX+q8/r8hhN7SdhSoYclUfgw0xLdzqzs8=; b=DyvMpBgH3jcTe4tGD66Q3hHRaB/9PvKjr7CjCyElclC8cfQ/24WT3lF7GJkWHo8ldd Fw17w1SYGVJYURCh9zcBzBoOENVxinSnzx9Jlk4tmYJu0eBPj10jhxjJVsysyJ9KbY41 frxiE/kHDuMuyndXhAgEv7bTBfkp+E/JkoT6oC4z4ASfUV9Ugg1dTv31kmjMHhXPtKwD 7gI/0ioh5dxXxPvRzBSNawI/IoVZDGlcS421BC3SHr7GDvvGtHNQejJNcbq+BXNxZ7it QhR7Bl4AlLZ0LSk08z91TxscJ1CfL9cOxAl5qdgGBUG2DkyLOyvQv6lXiRlF94XYmuCQ 7mKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:from:subject:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=0ev+vtzonlnX+q8/r8hhN7SdhSoYclUfgw0xLdzqzs8=; b=SK+wO9UCD0HzqLl5XpgUCE69qBXlkXnO+4Da9NTo5YrdkTZ/BTgv/evUBcTdC5SQBF Eshm+ryt/1uIOPbY+lObgLh+5b4NwExh9+sAmjHk/vKP7dOpYJD5OG45RmzIi2wkvDjF +oH12Y7LSYko5R3eUNrNY3vq+e/X2Lt9Wpa0ujp+nD7pEbTaJK2tek6yOWNE9A9xOuzv Kjg1gClFvYLxOaZ4kEsedWRMzQydvLP1a0ztRL6IF1J6eDvlNurD39vUNeVWTiRKrjmt tmyNmcE6TcxzpBbHpgs/+b3nzSrE81n6SOCC749fMH4/UZ+zHNZde27di/v67ZEdCiSi vNsw== X-Gm-Message-State: AOAM533Q49moKs4zQznDsxqqVqB6LR0F0zRVm4mO+r4frWMO16fpMIlm 646PHu7qZaxjEx4k/vHZ03eVVQ== X-Google-Smtp-Source: ABdhPJykr1/4vLJ05hWZfkzkyBgwb/gRY/c5eScaT6WtAsTrd7KTHhfuM90BOFUo6dbTiJlw7HosnQ== X-Received: by 2002:a5e:c912:: with SMTP id z18mr7119836iol.185.1605884395997; Fri, 20 Nov 2020 06:59:55 -0800 (PST) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id 10sm2046499ill.75.2020.11.20.06.59.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 20 Nov 2020 06:59:54 -0800 (PST) To: Networking Cc: Jakub Kicinski From: Jens Axboe Subject: [PATCH] tun: honor IOCB_NOWAIT flag Message-ID: Date: Fri, 20 Nov 2020 07:59:54 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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. Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe --- Had a bug report on io_uring, and it's due to tun not honoring IOCB_NOWAIT. Let's get this fixed. diff --git a/drivers/net/tun.c b/drivers/net/tun.c index be69d272052f..cd06cae76035 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1961,12 +1961,15 @@ 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; @@ -2185,10 +2188,15 @@ 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;