v4.19.13 snapshot.
diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c
new file mode 100644
index 0000000..ebfdaa3
--- /dev/null
+++ b/security/selinux/ss/hashtab.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implementation of the hash table type.
+ *
+ * Author : Stephen Smalley, <sds@tycho.nsa.gov>
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include "hashtab.h"
+
+static struct kmem_cache *hashtab_node_cachep;
+
+struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key),
+ int (*keycmp)(struct hashtab *h, const void *key1, const void *key2),
+ u32 size)
+{
+ struct hashtab *p;
+ u32 i;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return p;
+
+ p->size = size;
+ p->nel = 0;
+ p->hash_value = hash_value;
+ p->keycmp = keycmp;
+ p->htable = kmalloc_array(size, sizeof(*p->htable), GFP_KERNEL);
+ if (!p->htable) {
+ kfree(p);
+ return NULL;
+ }
+
+ for (i = 0; i < size; i++)
+ p->htable[i] = NULL;
+
+ return p;
+}
+
+int hashtab_insert(struct hashtab *h, void *key, void *datum)
+{
+ u32 hvalue;
+ struct hashtab_node *prev, *cur, *newnode;
+
+ cond_resched();
+
+ if (!h || h->nel == HASHTAB_MAX_NODES)
+ return -EINVAL;
+
+ hvalue = h->hash_value(h, key);
+ prev = NULL;
+ cur = h->htable[hvalue];
+ while (cur && h->keycmp(h, key, cur->key) > 0) {
+ prev = cur;
+ cur = cur->next;
+ }
+
+ if (cur && (h->keycmp(h, key, cur->key) == 0))
+ return -EEXIST;
+
+ newnode = kmem_cache_zalloc(hashtab_node_cachep, GFP_KERNEL);
+ if (!newnode)
+ return -ENOMEM;
+ newnode->key = key;
+ newnode->datum = datum;
+ if (prev) {
+ newnode->next = prev->next;
+ prev->next = newnode;
+ } else {
+ newnode->next = h->htable[hvalue];
+ h->htable[hvalue] = newnode;
+ }
+
+ h->nel++;
+ return 0;
+}
+
+void *hashtab_search(struct hashtab *h, const void *key)
+{
+ u32 hvalue;
+ struct hashtab_node *cur;
+
+ if (!h)
+ return NULL;
+
+ hvalue = h->hash_value(h, key);
+ cur = h->htable[hvalue];
+ while (cur && h->keycmp(h, key, cur->key) > 0)
+ cur = cur->next;
+
+ if (!cur || (h->keycmp(h, key, cur->key) != 0))
+ return NULL;
+
+ return cur->datum;
+}
+
+void hashtab_destroy(struct hashtab *h)
+{
+ u32 i;
+ struct hashtab_node *cur, *temp;
+
+ if (!h)
+ return;
+
+ for (i = 0; i < h->size; i++) {
+ cur = h->htable[i];
+ while (cur) {
+ temp = cur;
+ cur = cur->next;
+ kmem_cache_free(hashtab_node_cachep, temp);
+ }
+ h->htable[i] = NULL;
+ }
+
+ kfree(h->htable);
+ h->htable = NULL;
+
+ kfree(h);
+}
+
+int hashtab_map(struct hashtab *h,
+ int (*apply)(void *k, void *d, void *args),
+ void *args)
+{
+ u32 i;
+ int ret;
+ struct hashtab_node *cur;
+
+ if (!h)
+ return 0;
+
+ for (i = 0; i < h->size; i++) {
+ cur = h->htable[i];
+ while (cur) {
+ ret = apply(cur->key, cur->datum, args);
+ if (ret)
+ return ret;
+ cur = cur->next;
+ }
+ }
+ return 0;
+}
+
+
+void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
+{
+ u32 i, chain_len, slots_used, max_chain_len;
+ struct hashtab_node *cur;
+
+ slots_used = 0;
+ max_chain_len = 0;
+ for (i = 0; i < h->size; i++) {
+ cur = h->htable[i];
+ if (cur) {
+ slots_used++;
+ chain_len = 0;
+ while (cur) {
+ chain_len++;
+ cur = cur->next;
+ }
+
+ if (chain_len > max_chain_len)
+ max_chain_len = chain_len;
+ }
+ }
+
+ info->slots_used = slots_used;
+ info->max_chain_len = max_chain_len;
+}
+
+void __init hashtab_cache_init(void)
+{
+ hashtab_node_cachep = kmem_cache_create("hashtab_node",
+ sizeof(struct hashtab_node),
+ 0, SLAB_PANIC, NULL);
+}