From patchwork Tue Dec 23 05:40:22 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herbert Xu X-Patchwork-Id: 5530741 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Original-To: patchwork-linux-crypto@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id F021DBEEA8 for ; Tue, 23 Dec 2014 05:41:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 252202017D for ; Tue, 23 Dec 2014 05:41:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 369CE20115 for ; Tue, 23 Dec 2014 05:41:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754697AbaLWFkb (ORCPT ); Tue, 23 Dec 2014 00:40:31 -0500 Received: from helcar.apana.org.au ([209.40.204.226]:43314 "EHLO helcar.apana.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754713AbaLWFka (ORCPT ); Tue, 23 Dec 2014 00:40:30 -0500 Received: from gondolin.me.apana.org.au ([192.168.0.6]) by fornost.hengli.com.au with esmtp (Exim 4.80 #3 (Debian)) id 1Y3ICl-000848-8e; Tue, 23 Dec 2014 16:40:23 +1100 Received: from herbert by gondolin.me.apana.org.au with local (Exim 4.80) (envelope-from ) id 1Y3ICk-0007dg-OB; Tue, 23 Dec 2014 16:40:22 +1100 Subject: [PATCH 5/5] hwrng: core - Move hwrng_init call into set_current_rng References: <20141223053909.GA28001@gondor.apana.org.au> To: Fengguang Wu , Rusty Russell , LKP , linux-kernel@vger.kernel.org, Linux Crypto Mailing List , Amos Kong , m@bues.ch, mpm@selenic.com, amit.shah@redhat.com Message-Id: From: Herbert Xu Date: Tue, 23 Dec 2014 16:40:22 +1100 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We always do hwrng_init in set_current_rng. In fact, our current reference count system relies on this. So make this explicit by moving hwrng_init into set_current_rng. Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 787ef42..32a8a86 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -71,6 +71,7 @@ MODULE_PARM_DESC(default_quality, "default entropy content of hwrng per mill"); static void drop_current_rng(void); +static int hwrng_init(struct hwrng *rng); static void start_khwrngd(void); static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, @@ -103,11 +104,20 @@ static inline void cleanup_rng(struct kref *kref) complete(&rng->cleanup_done); } -static void set_current_rng(struct hwrng *rng) +static int set_current_rng(struct hwrng *rng) { + int err; + BUG_ON(!mutex_is_locked(&rng_mutex)); + + err = hwrng_init(rng); + if (err) + return err; + drop_current_rng(); current_rng = rng; + + return 0; } static void drop_current_rng(void) @@ -149,7 +159,7 @@ static void put_rng(struct hwrng *rng) mutex_unlock(&rng_mutex); } -static inline int hwrng_init(struct hwrng *rng) +static int hwrng_init(struct hwrng *rng) { if (kref_get_unless_zero(&rng->ref)) goto skip_init; @@ -310,15 +320,9 @@ static ssize_t hwrng_attr_current_store(struct device *dev, err = -ENODEV; list_for_each_entry(rng, &rng_list, list) { if (strcmp(rng->name, buf) == 0) { - if (rng == current_rng) { - err = 0; - break; - } - err = hwrng_init(rng); - if (err) - break; - set_current_rng(rng); err = 0; + if (rng != current_rng) + err = set_current_rng(rng); break; } } @@ -481,10 +485,9 @@ int hwrng_register(struct hwrng *rng) old_rng = current_rng; err = 0; if (!old_rng) { - err = hwrng_init(rng); + err = set_current_rng(rng); if (err) goto out_unlock; - set_current_rng(rng); } list_add_tail(&rng->list, &rng_list); @@ -518,8 +521,7 @@ void hwrng_unregister(struct hwrng *rng) tail = list_entry(rng_list.prev, struct hwrng, list); - if (hwrng_init(tail) == 0) - set_current_rng(tail); + set_current_rng(tail); } }