Increase the query cache insert grow retry

On s390x, the distribution of the query cache hash values is different
compared to other architectures, probably because of endianess and pointer
alignment being different (the hash key contains pointer values and integers).
This leads to the fact that ossl_ht_cache_QUERY_insert() is not always able to
add a query during the FIPS selftests, and thus ossl_ht_cache_QUERY_insert()
returns -1 is such cases.

Increase the number of retries inside ossl_ht_insert() to at least the
number elements per neighborhood plus 1. With this it is able to grow the
hash table enough so that the queries used during the FIPS selftest can
all be added to the hash table, even on s390x.

There is still no guarantee that the number of retries is enough for all
possible queries. It can still happen that certain queries can't be added to
the cache, even on other architectures. This does not really hurt, such
queries will just not be cached and are freshly fetched again the next time.

Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Nikola Pajkovsky <nikolap@openssl.org>
MergeDate: Mon Apr 27 05:56:53 2026
(Merged from https://github.com/openssl/openssl/pull/30903)

crypto/hashtable/hashtable.c

@@ -711,7 +711,7 @@ int ossl_ht_insert(HT *h, HT_KEY *key, HT_VALUE *data, HT_VALUE **olddata)
      */
     for (i = 0;
         (rc = ossl_ht_insert_locked(h, hash, newval, olddata)) == -1
-        && i < 4;
+        && i <= (int)NEIGHBORHOOD_LEN;
         ++i)
         if (!grow_hashtable(h, h->wpd.neighborhood_len)) {
             rc = -1;