Merge pull request #13649 from donaldsharp/unlock_the_node_or_else

[mirror_frr.git] / lib / typesafe.c

diff --git a/lib/typesafe.c b/lib/typesafe.c
index 0da35d0f8c185ef5c94f0ed3826505996a817b93..c0774479852da261af67d70572da58b55f2c77fa 100644 (file)
--- a/lib/typesafe.c
+++ b/lib/typesafe.c
@@ -85,6 +85,15 @@ void typesafe_hash_grow(struct thash_head *head)
        uint32_t newsize = head->count, i, j;
        uint8_t newshift, delta;
 
+       /* note hash_grow is called after head->count++, so newsize is
+        * guaranteed to be >= 1.  So the minimum argument to builtin_ctz
+        * below is 2, which returns 1, and that makes newshift >= 2.
+        *
+        * Calling hash_grow with a zero head->count would result in a
+        * malformed hash table that has tabshift == 1.
+        */
+       assert(head->count > 0);
+
        hash_consistency_check(head);
 
        newsize |= newsize >> 1;