Subject: [ 57/80] batman-adv: fix random jitter calculation

From: Greg Kroah-Hartman <[email-masked]>
Date: Wed, 9 Jan 2013 12:35:49 -0800

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Akinobu Mita <[email-masked]>

[ 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 <[email-masked]>
Acked-by: Antonio Quartulli <[email-masked]>
Cc: Marek Lindner <[email-masked]>
Cc: Simon Wunderlich <[email-masked]>
Cc: Antonio Quartulli <[email-masked]>
Cc: [email-masked]
Cc: "David S. Miller" <[email-masked]>
Cc: [email-masked]
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Greg Kroah-Hartman <[email-masked]>
---
 net/batman-adv/bat_iv_ogm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -72,7 +72,7 @@ static unsigned long bat_iv_ogm_emit_sen
 {
 	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 */