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Diffstat (limited to 'security/selinux/ss/avtab.c')
-rw-r--r--security/selinux/ss/avtab.c72
1 files changed, 56 insertions, 16 deletions
diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
index a3dd9faa19c0..b64f2772b030 100644
--- a/security/selinux/ss/avtab.c
+++ b/security/selinux/ss/avtab.c
@@ -25,10 +25,43 @@
static struct kmem_cache *avtab_node_cachep;
-static inline int avtab_hash(struct avtab_key *keyp, u16 mask)
+/* Based on MurmurHash3, written by Austin Appleby and placed in the
+ * public domain.
+ */
+static inline int avtab_hash(struct avtab_key *keyp, u32 mask)
{
- return ((keyp->target_class + (keyp->target_type << 2) +
- (keyp->source_type << 9)) & mask);
+ static const u32 c1 = 0xcc9e2d51;
+ static const u32 c2 = 0x1b873593;
+ static const u32 r1 = 15;
+ static const u32 r2 = 13;
+ static const u32 m = 5;
+ static const u32 n = 0xe6546b64;
+
+ u32 hash = 0;
+
+#define mix(input) { \
+ u32 v = input; \
+ v *= c1; \
+ v = (v << r1) | (v >> (32 - r1)); \
+ v *= c2; \
+ hash ^= v; \
+ hash = (hash << r2) | (hash >> (32 - r2)); \
+ hash = hash * m + n; \
+}
+
+ mix(keyp->target_class);
+ mix(keyp->target_type);
+ mix(keyp->source_type);
+
+#undef mix
+
+ hash ^= hash >> 16;
+ hash *= 0x85ebca6b;
+ hash ^= hash >> 13;
+ hash *= 0xc2b2ae35;
+ hash ^= hash >> 16;
+
+ return hash & mask;
}
static struct avtab_node*
@@ -46,8 +79,12 @@ avtab_insert_node(struct avtab *h, int hvalue,
newnode->next = prev->next;
prev->next = newnode;
} else {
- newnode->next = h->htable[hvalue];
- h->htable[hvalue] = newnode;
+ newnode->next = flex_array_get_ptr(h->htable, hvalue);
+ if (flex_array_put_ptr(h->htable, hvalue, newnode,
+ GFP_KERNEL|__GFP_ZERO)) {
+ kmem_cache_free(avtab_node_cachep, newnode);
+ return NULL;
+ }
}
h->nel++;
@@ -64,7 +101,7 @@ static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_dat
return -EINVAL;
hvalue = avtab_hash(key, h->mask);
- for (prev = NULL, cur = h->htable[hvalue];
+ for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
cur;
prev = cur, cur = cur->next) {
if (key->source_type == cur->key.source_type &&
@@ -104,7 +141,7 @@ avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datu
if (!h || !h->htable)
return NULL;
hvalue = avtab_hash(key, h->mask);
- for (prev = NULL, cur = h->htable[hvalue];
+ for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
cur;
prev = cur, cur = cur->next) {
if (key->source_type == cur->key.source_type &&
@@ -135,7 +172,8 @@ struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
return NULL;
hvalue = avtab_hash(key, h->mask);
- for (cur = h->htable[hvalue]; cur; cur = cur->next) {
+ for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
+ cur = cur->next) {
if (key->source_type == cur->key.source_type &&
key->target_type == cur->key.target_type &&
key->target_class == cur->key.target_class &&
@@ -170,7 +208,8 @@ avtab_search_node(struct avtab *h, struct avtab_key *key)
return NULL;
hvalue = avtab_hash(key, h->mask);
- for (cur = h->htable[hvalue]; cur; cur = cur->next) {
+ for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
+ cur = cur->next) {
if (key->source_type == cur->key.source_type &&
key->target_type == cur->key.target_type &&
key->target_class == cur->key.target_class &&
@@ -228,15 +267,14 @@ void avtab_destroy(struct avtab *h)
return;
for (i = 0; i < h->nslot; i++) {
- cur = h->htable[i];
+ cur = flex_array_get_ptr(h->htable, i);
while (cur) {
temp = cur;
cur = cur->next;
kmem_cache_free(avtab_node_cachep, temp);
}
- h->htable[i] = NULL;
}
- kfree(h->htable);
+ flex_array_free(h->htable);
h->htable = NULL;
h->nslot = 0;
h->mask = 0;
@@ -251,7 +289,7 @@ int avtab_init(struct avtab *h)
int avtab_alloc(struct avtab *h, u32 nrules)
{
- u16 mask = 0;
+ u32 mask = 0;
u32 shift = 0;
u32 work = nrules;
u32 nslot = 0;
@@ -270,7 +308,8 @@ int avtab_alloc(struct avtab *h, u32 nrules)
nslot = MAX_AVTAB_HASH_BUCKETS;
mask = nslot - 1;
- h->htable = kcalloc(nslot, sizeof(*(h->htable)), GFP_KERNEL);
+ h->htable = flex_array_alloc(sizeof(struct avtab_node *), nslot,
+ GFP_KERNEL | __GFP_ZERO);
if (!h->htable)
return -ENOMEM;
@@ -293,7 +332,7 @@ void avtab_hash_eval(struct avtab *h, char *tag)
max_chain_len = 0;
chain2_len_sum = 0;
for (i = 0; i < h->nslot; i++) {
- cur = h->htable[i];
+ cur = flex_array_get_ptr(h->htable, i);
if (cur) {
slots_used++;
chain_len = 0;
@@ -534,7 +573,8 @@ int avtab_write(struct policydb *p, struct avtab *a, void *fp)
return rc;
for (i = 0; i < a->nslot; i++) {
- for (cur = a->htable[i]; cur; cur = cur->next) {
+ for (cur = flex_array_get_ptr(a->htable, i); cur;
+ cur = cur->next) {
rc = avtab_write_item(p, cur, fp);
if (rc)
return rc;