Index: kernel/generic/include/adt/hash_table.h
===================================================================
--- kernel/generic/include/adt/hash_table.h	(revision 4805495a910f793f8918c13f029a38a5bb548154)
+++ kernel/generic/include/adt/hash_table.h	(revision f27e21ddaafbb7195a9fa323a76c7813b7d6b41b)
@@ -53,5 +53,5 @@
 
 	/** Returns the hash of the key. */
-	size_t (*key_hash)(void *key);
+	size_t (*key_hash)(const void *key);
 
 	/** True if the items are equal (have the same lookup keys). */
@@ -59,5 +59,5 @@
 
 	/** Returns true if the key is equal to the item's lookup key. */
-	bool (*key_equal)(void *key, const ht_link_t *item);
+	bool (*key_equal)(const void *key, const ht_link_t *item);
 
 	/** Hash table item removal callback.
@@ -94,8 +94,8 @@
 extern void hash_table_insert(hash_table_t *, ht_link_t *);
 extern bool hash_table_insert_unique(hash_table_t *, ht_link_t *);
-extern ht_link_t *hash_table_find(const hash_table_t *, void *);
+extern ht_link_t *hash_table_find(const hash_table_t *, const void *);
 extern ht_link_t *hash_table_find_next(const hash_table_t *, ht_link_t *,
     ht_link_t *);
-extern size_t hash_table_remove(hash_table_t *, void *);
+extern size_t hash_table_remove(hash_table_t *, const void *);
 extern void hash_table_remove_item(hash_table_t *, ht_link_t *);
 extern void hash_table_apply(hash_table_t *, bool (*)(ht_link_t *, void *),