The following commit has been merged in the master branch: commit 26893e7e928e1790852b072edb9bff3c1309e111 Author: Sven Eckelmann sven@narfation.org Date: Mon Apr 13 21:23:29 2020 +0200

batman-adv: Utilize prandom_u32_max for random [0, max) values

The kernel provides a function to create random values from 0 - (max-1) since commit f337db64af05 ("random32: add prandom_u32_max and convert open coded users"). Simply use this function to replace code sections which use prandom_u32 and a handcrafted method to map it to the correct range.

Signed-off-by: Sven Eckelmann sven@narfation.org

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index a7c8dd7ae513..e87f19c82e8d 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -280,7 +280,7 @@ 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 += prandom_u32() % (2 * BATADV_JITTER); + msecs += prandom_u32_max(2 * BATADV_JITTER);

return jiffies + msecs_to_jiffies(msecs); } @@ -288,7 +288,7 @@ batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv) /* when do we schedule a ogm packet to be sent */ static unsigned long batadv_iv_ogm_fwd_send_time(void) { - return jiffies + msecs_to_jiffies(prandom_u32() % (BATADV_JITTER / 2)); + return jiffies + msecs_to_jiffies(prandom_u32_max(BATADV_JITTER / 2)); }

/* apply hop penalty for a normal link */ diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index 1e3172db7492..353e49c40e7f 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -49,7 +49,7 @@ static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface) unsigned int msecs;

msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER; - msecs += prandom_u32() % (2 * BATADV_JITTER); + msecs += prandom_u32_max(2 * BATADV_JITTER);

queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq, msecs_to_jiffies(msecs)); diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 969466218999..0959d32be65c 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -88,7 +88,7 @@ static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface) unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;

/* msecs * [0.9, 1.1] */ - msecs += prandom_u32() % (msecs / 5) - (msecs / 10); + msecs += prandom_u32_max(msecs / 5) - (msecs / 10); queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq, msecs_to_jiffies(msecs / 1000)); } @@ -107,7 +107,7 @@ static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) return;

msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; - msecs += prandom_u32() % (2 * BATADV_JITTER); + msecs += prandom_u32_max(2 * BATADV_JITTER); queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq, msecs_to_jiffies(msecs)); }