From patchwork Tue Sep 5 12:38:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gilad Ben-Yossef X-Patchwork-Id: 9938615 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AD4996089F for ; Tue, 5 Sep 2017 12:39:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9F0EB1FF82 for ; Tue, 5 Sep 2017 12:39:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9391C2897F; Tue, 5 Sep 2017 12:39:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 37652212E8 for ; Tue, 5 Sep 2017 12:39:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751445AbdIEMjm (ORCPT ); Tue, 5 Sep 2017 08:39:42 -0400 Received: from foss.arm.com ([217.140.101.70]:38928 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750891AbdIEMjf (ORCPT ); Tue, 5 Sep 2017 08:39:35 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 880DD15BF; Tue, 5 Sep 2017 05:39:34 -0700 (PDT) Received: from gby.kfn.arm.com (unknown [10.45.48.140]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8809E3F3E1; Tue, 5 Sep 2017 05:39:25 -0700 (PDT) From: Gilad Ben-Yossef To: Herbert Xu , "David S. Miller" , Jonathan Corbet , David Howells , Tom Lendacky , Gary Hook , Boris Brezillon , Arnaud Ebalard , Matthias Brugger , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Shaohua Li , Steve French , "Theodore Y. Ts'o" , Jaegeuk Kim , Steffen Klassert , Alexey Kuznetsov , Hideaki YOSHIFUJI , Mimi Zohar , Dmitry Kasatkin , James Morris , "Serge E. Hallyn" , linux-crypto@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-raid@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-fscrypt@vger.kernel.org, netdev@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, linux-ima-user@lists.sourceforge.net, linux-security-module@vger.kernel.org Cc: Ofir Drang Subject: [PATCH v8 01/20] crypto: change transient busy return code to -EAGAIN Date: Tue, 5 Sep 2017 15:38:40 +0300 Message-Id: <1504615144-29770-2-git-send-email-gilad@benyossef.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1504615144-29770-1-git-send-email-gilad@benyossef.com> References: <1504615144-29770-1-git-send-email-gilad@benyossef.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP The crypto API was using the -EBUSY return value to indicate both a hard failure to submit a crypto operation into a transformation provider when the latter was busy and the backlog mechanism was not enabled as well as a notification that the operation was queued into the backlog when the backlog mechanism was enabled. Having the same return code indicate two very different conditions depending on a flag is both error prone and requires extra runtime check like the following to discern between the cases: if (err == -EINPROGRESS || (err == -EBUSY && (ahash_request_flags(req) & CRYPTO_TFM_REQ_MAY_BACKLOG))) This patch changes the return code used to indicate a crypto op failed due to the transformation provider being transiently busy to -EAGAIN. Signed-off-by: Gilad Ben-Yossef --- crypto/algapi.c | 6 ++++-- crypto/algif_hash.c | 20 +++++++++++++++++--- crypto/cryptd.c | 4 +--- 3 files changed, 22 insertions(+), 8 deletions(-) diff --git a/crypto/algapi.c b/crypto/algapi.c index aa699ff..916bee3 100644 --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -897,9 +897,11 @@ int crypto_enqueue_request(struct crypto_queue *queue, int err = -EINPROGRESS; if (unlikely(queue->qlen >= queue->max_qlen)) { - err = -EBUSY; - if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) + if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) { + err = -EAGAIN; goto out; + } + err = -EBUSY; if (queue->backlog == &queue->list) queue->backlog = &request->list; } diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c index 5e92bd2..3b3c154 100644 --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -39,6 +39,20 @@ struct algif_hash_tfm { bool has_key; }; +/* Previous versions of crypto_* ops used to return -EBUSY + * rather than -EAGAIN to indicate being tied up. The in + * kernel API changed but we don't want to break the user + * space API. As only the hash user interface exposed this + * error ever to the user, do the translation here. + */ +static inline int crypto_user_err(int err) +{ + if (err == -EAGAIN) + return -EBUSY; + + return err; +} + static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx) { unsigned ds; @@ -136,7 +150,7 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg, unlock: release_sock(sk); - return err ?: copied; + return err ? crypto_user_err(err) : copied; } static ssize_t hash_sendpage(struct socket *sock, struct page *page, @@ -188,7 +202,7 @@ static ssize_t hash_sendpage(struct socket *sock, struct page *page, unlock: release_sock(sk); - return err ?: size; + return err ? crypto_user_err(err) : size; } static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, @@ -236,7 +250,7 @@ static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, hash_free_result(sk, ctx); release_sock(sk); - return err ?: len; + return err ? crypto_user_err(err) : len; } static int hash_accept(struct socket *sock, struct socket *newsock, int flags, diff --git a/crypto/cryptd.c b/crypto/cryptd.c index 0508c48..d1dbdce 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -137,16 +137,14 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue, int cpu, err; struct cryptd_cpu_queue *cpu_queue; atomic_t *refcnt; - bool may_backlog; cpu = get_cpu(); cpu_queue = this_cpu_ptr(queue->cpu_queue); err = crypto_enqueue_request(&cpu_queue->queue, request); refcnt = crypto_tfm_ctx(request->tfm); - may_backlog = request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG; - if (err == -EBUSY && !may_backlog) + if (err == -EAGAIN) goto out_put_cpu; queue_work_on(cpu, kcrypto_wq, &cpu_queue->work);