netfilter: hashlimit: do not use indirect calls during gc

no need, just use a simple boolean to indicate we want to reap all
entries.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/xt_hashlimit.c

@@ -357,21 +357,7 @@ static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg,
 	return 0;
 }
 
-static bool select_all(const struct xt_hashlimit_htable *ht,
-		       const struct dsthash_ent *he)
-{
-	return true;
-}
-
-static bool select_gc(const struct xt_hashlimit_htable *ht,
-		      const struct dsthash_ent *he)
-{
-	return time_after_eq(jiffies, he->expires);
-}
-
-static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
-			bool (*select)(const struct xt_hashlimit_htable *ht,
-				      const struct dsthash_ent *he))
+static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, bool select_all)
 {
 	unsigned int i;
 
@@ -381,7 +367,7 @@ static void htable_selective_cleanup(struct xt_hashlimit_htable *ht,
 
 		spin_lock_bh(&ht->lock);
 		hlist_for_each_entry_safe(dh, n, &ht->hash[i], node) {
-			if ((*select)(ht, dh))
+			if (time_after_eq(jiffies, dh->expires) || select_all)
 				dsthash_free(ht, dh);
 		}
 		spin_unlock_bh(&ht->lock);
@@ -395,7 +381,7 @@ static void htable_gc(struct work_struct *work)
 
 	ht = container_of(work, struct xt_hashlimit_htable, gc_work.work);
 
-	htable_selective_cleanup(ht, select_gc);
+	htable_selective_cleanup(ht, false);
 
 	queue_delayed_work(system_power_efficient_wq,
 			   &ht->gc_work, msecs_to_jiffies(ht->cfg.gc_interval));
@@ -419,7 +405,7 @@ static void htable_destroy(struct xt_hashlimit_htable *hinfo)
 {
 	cancel_delayed_work_sync(&hinfo->gc_work);
 	htable_remove_proc_entry(hinfo);
-	htable_selective_cleanup(hinfo, select_all);
+	htable_selective_cleanup(hinfo, true);
 	kfree(hinfo->name);
 	vfree(hinfo);
 }