From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20130326173600.211530324@goodmis.org> Date: Tue, 26 Mar 2013 13:21:01 -0400 From: Steven Rostedt References: <20130326172059.136127374@goodmis.org> Content-Disposition: inline; filename=0002-batman-adv-fix-random-jitter-calculation.patch Subject: [B.A.T.M.A.N.] [PATCH 02/86] batman-adv: fix random jitter calculation Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Akinobu Mita , Simon Wunderlich , Marek Lindner , "David S. Miller" 3.6.11.1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita [ Upstream commit 143cdd8f33909ff5a153e3f02048738c5964ba26 ] 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 --- 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 469daab..1476f26 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -119,7 +119,7 @@ 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); } -- 1.7.10.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759997Ab3CZSEp (ORCPT ); Tue, 26 Mar 2013 14:04:45 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:4135 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753711Ab3CZRgB (ORCPT ); Tue, 26 Mar 2013 13:36:01 -0400 X-Authority-Analysis: v=2.0 cv=H5hZMpki c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=RGOdwypfkeUA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=d467tr5auRgA:10 a=pGLkceISAAAA:8 a=K33ine3eAAAA:8 a=sPyYOCAXAAAA:8 a=J1Y8HTJGAAAA:8 a=VwQbUJbxAAAA:8 a=GZK3lcuhIWR5GrNAc6YA:9 a=MSl-tDqOz04A:10 a=o7nkWXKJ22EA:10 a=6UCq8DqREAUA:10 a=4N9Db7Z2_RYA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-Id: <20130326173600.211530324@goodmis.org> User-Agent: quilt/0.60-1 Date: Tue, 26 Mar 2013 13:21:01 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Akinobu Mita , Antonio Quartulli , Marek Lindner , Simon Wunderlich , , "David S. Miller" , Subject: [PATCH 02/86] batman-adv: fix random jitter calculation References: <20130326172059.136127374@goodmis.org> Content-Disposition: inline; filename=0002-batman-adv-fix-random-jitter-calculation.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita [ Upstream commit 143cdd8f33909ff5a153e3f02048738c5964ba26 ] 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 --- 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 469daab..1476f26 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -119,7 +119,7 @@ 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); } -- 1.7.10.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [PATCH 02/86] batman-adv: fix random jitter calculation Date: Tue, 26 Mar 2013 13:21:01 -0400 Message-ID: <20130326173600.211530324@goodmis.org> References: <20130326172059.136127374@goodmis.org> Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, b.a.t.m.a.n-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org, Akinobu Mita , Simon Wunderlich , Marek Lindner , "David S. Miller" To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: Content-Disposition: inline; filename=0002-batman-adv-fix-random-jitter-calculation.patch List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: b.a.t.m.a.n-bounces-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org Sender: "B.A.T.M.A.N" List-Id: netdev.vger.kernel.org 3.6.11.1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita [ Upstream commit 143cdd8f33909ff5a153e3f02048738c5964ba26 ] 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-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org Cc: "David S. Miller" Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: David S. Miller --- 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 469daab..1476f26 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -119,7 +119,7 @@ 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); } -- 1.7.10.4