From patchwork Mon Dec 24 02:14:06 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Akinobu Mita X-Patchwork-Id: 208014 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 266EE2C0087 for ; Mon, 24 Dec 2012 13:22:54 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752773Ab2LXCWj (ORCPT ); Sun, 23 Dec 2012 21:22:39 -0500 Received: from mail-pb0-f54.google.com ([209.85.160.54]:58453 "EHLO mail-pb0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752577Ab2LXCWh (ORCPT ); Sun, 23 Dec 2012 21:22:37 -0500 Received: by mail-pb0-f54.google.com with SMTP id wz12so3714338pbc.27 for ; Sun, 23 Dec 2012 18:22:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=U2F5VzdVFCCxzSwGrp6WTDCuxdocIXH6YLHtEO0YKxs=; b=KtfXv8sDMz4Uw7eWh8GPiW4s/BskPMrRUjEsgHmjoIRLPSZiNAdgN6SDvAmRqreF2g YINHzPHRKLaQKEX5dqS2uKChD1l1PA/e+ZMftS2Y+wujwlnM5Gi64GWcEL70B6Qpyoqv 15IyalSK/cCmneW81Xh+hJXn0KA600cBEffMb/yrZbolOA7jTVAzlGneoyqrguaZsmaR ZXaU/MNf7jJ/AJKvybknuF++pzBxlrJSduZNw542Up4D6ow/2URgP1FoeiAa4Z9sIIxc u2ezf1nCQ343DLots3Vz120buxM45grKexZTvIJB454PKsY5Az3cDnnjN7U9wa/EODss 1hYw== X-Received: by 10.68.138.229 with SMTP id qt5mr61720791pbb.122.1356315311119; Sun, 23 Dec 2012 18:15:11 -0800 (PST) Received: from localhost.localdomain (p2126-ipbf3106hodogaya.kanagawa.ocn.ne.jp. [114.149.157.126]) by mx.google.com with ESMTPS id wr4sm11379909pbc.72.2012.12.23.18.15.08 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 23 Dec 2012 18:15:10 -0800 (PST) From: Akinobu Mita To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org Cc: Akinobu Mita , Marek Lindner , Simon Wunderlich , Antonio Quartulli , b.a.t.m.a.n@lists.open-mesh.org, "David S. Miller" , netdev@vger.kernel.org Subject: [PATCH 19/29] batman-adv: fix random jitter calculation Date: Mon, 24 Dec 2012 11:14:06 +0900 Message-Id: <1356315256-6572-20-git-send-email-akinobu.mita@gmail.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1356315256-6572-1-git-send-email-akinobu.mita@gmail.com> References: <1356315256-6572-1-git-send-email-akinobu.mita@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 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 Acked-by: Antonio Quartulli --- 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 9f3925a..7d02ebd 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -123,7 +123,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv) unsigned int msecs; msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; - msecs += (random32() % 2 * BATADV_JITTER); + msecs += random32() % (2 * BATADV_JITTER); return jiffies + msecs_to_jiffies(msecs); }