This is a note to let you know that I have just added a patch titled
batman-adv: fix random jitter calculation
to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linu...
If you, or anyone else, feels it should not be added to this tree, please reply to this email.
For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks. -Herton
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From 12a62234843bc692176f3dc51492cfe84156f1c4 Mon Sep 17 00:00:00 2001
From: Akinobu Mita akinobu.mita@gmail.com Date: Wed, 26 Dec 2012 02:32:10 +0000 Subject: [PATCH] batman-adv: fix random jitter calculation
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 akinobu.mita@gmail.com Acked-by: Antonio Quartulli ordex@autistici.org Cc: Marek Lindner lindner_marek@yahoo.de Cc: Simon Wunderlich siwu@hrz.tu-chemnitz.de Cc: Antonio Quartulli ordex@autistici.org Cc: b.a.t.m.a.n@lists.open-mesh.org Cc: "David S. Miller" davem@davemloft.net Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Herton Ronaldo Krzesinski herton.krzesinski@canonical.com --- 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 */ -- 1.7.9.5