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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3E93C433EF for ; Thu, 30 Jun 2022 09:18:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234084AbiF3JSr (ORCPT ); Thu, 30 Jun 2022 05:18:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234166AbiF3JSV (ORCPT ); Thu, 30 Jun 2022 05:18:21 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F21E2F655 for ; Thu, 30 Jun 2022 02:17:05 -0700 (PDT) Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 25U7TSJ7021964 for ; Thu, 30 Jun 2022 02:17:05 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=yNGWca9EZYptSu02EU61qEdS1WccUVHJPmvgfuLJvJI=; b=TSljtTkcvad2N/d3wiu+TNZNeKjk30v9g/O3LSbXK7QugXgu9b7nqgrlSlTP4DWmfbMJ 4a7DoE9qmq34HqR54x68n3JEQvJy6pQ7obYj9yoeIzVcq4b2KCzSNG3NbpLz/XtF/pgj v8m3HyGuFn6MNT7qWGwnGEnRedL62Gfkadw= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3h17fmgg2n-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 30 Jun 2022 02:17:05 -0700 Received: from snc-exhub201.TheFacebook.com (2620:10d:c085:21d::7) by snc-exhub101.TheFacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Thu, 30 Jun 2022 02:17:04 -0700 Received: from twshared5640.09.ash9.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Thu, 30 Jun 2022 02:17:03 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id 9A2E82599FD2; Thu, 30 Jun 2022 02:14:08 -0700 (PDT) From: Dylan Yudaken To: Jens Axboe , Pavel Begunkov , CC: , , Dylan Yudaken Subject: [PATCH v2 for-next 03/12] io_uring: allow iov_len = 0 for recvmsg and buffer select Date: Thu, 30 Jun 2022 02:12:22 -0700 Message-ID: <20220630091231.1456789-4-dylany@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220630091231.1456789-1-dylany@fb.com> References: <20220630091231.1456789-1-dylany@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: d6WzIQwN2xdiDq10fcoV_nyUunayhZm_ X-Proofpoint-ORIG-GUID: d6WzIQwN2xdiDq10fcoV_nyUunayhZm_ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-06-30_05,2022-06-28_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org When using BUFFER_SELECT there is no technical requirement that the user actually provides iov, and this removes one copy_from_user call. So allow iov_len to be 0. Signed-off-by: Dylan Yudaken --- io_uring/net.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/io_uring/net.c b/io_uring/net.c index 19a805c3814c..5e84f7ab92a3 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -300,12 +300,18 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *r= eq, return ret; =20 if (req->flags & REQ_F_BUFFER_SELECT) { - if (iov_len > 1) + if (iov_len =3D=3D 0) { + sr->len =3D iomsg->fast_iov[0].iov_len =3D 0; + iomsg->fast_iov[0].iov_base =3D NULL; + iomsg->free_iov =3D NULL; + } else if (iov_len > 1) { return -EINVAL; - if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov))) - return -EFAULT; - sr->len =3D iomsg->fast_iov[0].iov_len; - iomsg->free_iov =3D NULL; + } else { + if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov))) + return -EFAULT; + sr->len =3D iomsg->fast_iov[0].iov_len; + iomsg->free_iov =3D NULL; + } } else { iomsg->free_iov =3D iomsg->fast_iov; ret =3D __import_iovec(READ, uiov, iov_len, UIO_FASTIOV, --=20 2.30.2