Commit 143cdd8f authored by Akinobu Mita's avatar Akinobu Mita Committed by David S. Miller

batman-adv: fix random jitter calculation

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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: default avatarAntonio 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: default avatarDavid S. Miller <davem@davemloft.net>
parent cf0be880
...@@ -123,7 +123,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv) ...@@ -123,7 +123,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
unsigned int msecs; unsigned int msecs;
msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; 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); return jiffies + msecs_to_jiffies(msecs);
} }
......
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