From patchwork Wed Jan 16 15:56:22 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 213237 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 42E972C008F for ; Thu, 17 Jan 2013 23:31:33 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1Tvocl-00035e-VD; Thu, 17 Jan 2013 12:31:15 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TvVY8-0006Ir-2X for kernel-team@lists.ubuntu.com; Wed, 16 Jan 2013 16:09:12 +0000 Received: from [177.132.109.150] (helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1TvVY6-0007Hh-Qn; Wed, 16 Jan 2013 16:09:11 +0000 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 182/222] batman-adv: fix random jitter calculation Date: Wed, 16 Jan 2013 13:56:22 -0200 Message-Id: <1358351822-7675-183-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> References: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> X-Extended-Stable: 3.5 X-Mailman-Approved-At: Thu, 17 Jan 2013 12:31:12 +0000 Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Akinobu Mita , Simon Wunderlich , Antonio Quartulli , Marek Lindner , "David S. Miller" X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com 3.5.7.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita commit 143cdd8f33909ff5a153e3f02048738c5964ba26 upstream. batadv_iv_ogm_emit_send_time() attempts to calculates a random integer in the range of 'orig_interval +- BATADV_JITTER' by the below lines. msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; msecs += (random32() % 2 * BATADV_JITTER); But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER' because '%' and '*' have same precedence and associativity is left-to-right. This adds the parentheses at the appropriate position so that it matches original intension. Signed-off-by: Akinobu Mita Acked-by: Antonio Quartulli Cc: Marek Lindner Cc: Simon Wunderlich Cc: Antonio Quartulli Cc: b.a.t.m.a.n@lists.open-mesh.org Cc: "David S. Miller" Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller Signed-off-by: Herton Ronaldo Krzesinski --- net/batman-adv/bat_iv_ogm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index dc53798..bcf3760 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -117,7 +117,7 @@ static unsigned long bat_iv_ogm_emit_send_time(const struct bat_priv *bat_priv) { return jiffies + msecs_to_jiffies( atomic_read(&bat_priv->orig_interval) - - JITTER + (random32() % 2*JITTER)); + JITTER + (random32() % (2*JITTER))); } /* when do we schedule a ogm packet to be sent */