From nobody Tue Feb 10 02:59:06 2026 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 BCED1C76196 for ; Fri, 31 Mar 2023 16:13:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233351AbjCaQN2 (ORCPT ); Fri, 31 Mar 2023 12:13:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233081AbjCaQMI (ORCPT ); Fri, 31 Mar 2023 12:12:08 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F9AA1EFF3 for ; Fri, 31 Mar 2023 09:10:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680279032; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bQ5QnEnteMQfZ4j7G0XrCpLzGl+D3sZ9ge7q0vobANw=; b=KFD11+19/rtgjRN53suD2tLpatNQeswN17GfhuPYoQfldzUtNGUHn742LO/iB43qgnfdY1 4hkg9ALV/GdE5HdvXqGdeRlpTGPJizTRy8BiVG4bUulyFghafRvUQzVg/RLzcez9pR+jEQ eGt9HPcA/6EoAkektRVzvXqxgJ9oxE0= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-451-zyE999oJOe6JnagrFD2R3w-1; Fri, 31 Mar 2023 12:10:29 -0400 X-MC-Unique: zyE999oJOe6JnagrFD2R3w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1847B85A5B1; Fri, 31 Mar 2023 16:10:28 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0691D1121315; Fri, 31 Mar 2023 16:10:25 +0000 (UTC) From: David Howells To: Matthew Wilcox , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: David Howells , Al Viro , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Herbert Xu , linux-crypto@vger.kernel.org Subject: [PATCH v3 24/55] crypto: af_alg: Support MSG_SPLICE_PAGES Date: Fri, 31 Mar 2023 17:08:43 +0100 Message-Id: <20230331160914.1608208-25-dhowells@redhat.com> In-Reply-To: <20230331160914.1608208-1-dhowells@redhat.com> References: <20230331160914.1608208-1-dhowells@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Make AF_ALG sendmsg() support MSG_SPLICE_PAGES. This causes pages to be spliced from the source iterator. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. [!] Note that this makes use of netfs_extract_iter_to_sg() from netfslib. This probably needs moving to core code somewhere. Signed-off-by: David Howells cc: Herbert Xu cc: "David S. Miller" cc: Eric Dumazet cc: Jakub Kicinski cc: Paolo Abeni cc: Jens Axboe cc: Matthew Wilcox cc: linux-crypto@vger.kernel.org cc: netdev@vger.kernel.org --- crypto/Kconfig | 1 + crypto/af_alg.c | 28 ++++++++++++++++++++++++++-- crypto/algif_aead.c | 22 +++++++++++----------- crypto/algif_skcipher.c | 8 ++++---- 4 files changed, 42 insertions(+), 17 deletions(-) diff --git a/crypto/Kconfig b/crypto/Kconfig index 9c86f7045157..8c04ecbb4395 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -1297,6 +1297,7 @@ menu "Userspace interface" =20 config CRYPTO_USER_API tristate + select NETFS_SUPPORT # for netfs_extract_iter_to_sg() =20 config CRYPTO_USER_API_HASH tristate "Hash algorithms" diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 483821e310e9..3088ab298632 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -941,6 +941,10 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr = *msg, size_t size, bool init =3D false; int err =3D 0; =20 + if ((msg->msg_flags & MSG_SPLICE_PAGES) && + !iov_iter_is_bvec(&msg->msg_iter)) + return -EINVAL; + if (msg->msg_controllen) { err =3D af_alg_cmsg_send(msg, &con); if (err) @@ -986,7 +990,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *= msg, size_t size, while (size) { struct scatterlist *sg; size_t len =3D size; - size_t plen; + ssize_t plen; =20 /* use the existing memory in an allocated page */ if (ctx->merge) { @@ -1031,7 +1035,27 @@ int af_alg_sendmsg(struct socket *sock, struct msghd= r *msg, size_t size, if (sgl->cur) sg_unmark_end(sg + sgl->cur - 1); =20 - if (1 /* TODO check MSG_SPLICE_PAGES */) { + if (msg->msg_flags & MSG_SPLICE_PAGES) { + struct sg_table sgtable =3D { + .sgl =3D sg, + .nents =3D sgl->cur, + .orig_nents =3D sgl->cur, + }; + + plen =3D netfs_extract_iter_to_sg(&msg->msg_iter, len, + &sgtable, MAX_SGL_ENTS, 0); + if (plen < 0) { + err =3D plen; + goto unlock; + } + + for (; sgl->cur < sgtable.nents; sgl->cur++) + get_page(sg_page(&sg[sgl->cur])); + len -=3D plen; + ctx->used +=3D plen; + copied +=3D plen; + size -=3D plen; + } else { do { struct page *pg; unsigned int i =3D sgl->cur; diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c index f6aa3856d8d5..b16111a3025a 100644 --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -9,8 +9,8 @@ * The following concept of the memory management is used: * * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is - * filled by user space with the data submitted via sendpage/sendmsg. Fill= ing - * up the TX SGL does not cause a crypto operation -- the data will only be + * filled by user space with the data submitted via sendpage. Filling up + * the TX SGL does not cause a crypto operation -- the data will only be * tracked by the kernel. Upon receipt of one recvmsg call, the caller must * provide a buffer which is tracked with the RX SGL. * @@ -113,19 +113,19 @@ static int _aead_recvmsg(struct socket *sock, struct = msghdr *msg, } =20 /* - * Data length provided by caller via sendmsg/sendpage that has not - * yet been processed. + * Data length provided by caller via sendmsg that has not yet been + * processed. */ used =3D ctx->used; =20 /* - * Make sure sufficient data is present -- note, the same check is - * also present in sendmsg/sendpage. The checks in sendpage/sendmsg - * shall provide an information to the data sender that something is - * wrong, but they are irrelevant to maintain the kernel integrity. - * We need this check here too in case user space decides to not honor - * the error message in sendmsg/sendpage and still call recvmsg. This - * check here protects the kernel integrity. + * Make sure sufficient data is present -- note, the same check is also + * present in sendmsg. The checks in sendmsg shall provide an + * information to the data sender that something is wrong, but they are + * irrelevant to maintain the kernel integrity. We need this check + * here too in case user space decides to not honor the error message + * in sendmsg and still call recvmsg. This check here protects the + * kernel integrity. */ if (!aead_sufficient_data(sk)) return -EINVAL; diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index a251cd6bd5b9..b1f321b9f846 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -9,10 +9,10 @@ * The following concept of the memory management is used: * * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is - * filled by user space with the data submitted via sendpage/sendmsg. Fill= ing - * up the TX SGL does not cause a crypto operation -- the data will only be - * tracked by the kernel. Upon receipt of one recvmsg call, the caller must - * provide a buffer which is tracked with the RX SGL. + * filled by user space with the data submitted via sendmsg. Filling up th= e TX + * SGL does not cause a crypto operation -- the data will only be tracked = by + * the kernel. Upon receipt of one recvmsg call, the caller must provide a + * buffer which is tracked with the RX SGL. * * During the processing of the recvmsg operation, the cipher request is * allocated and prepared. As part of the recvmsg operation, the processed