selinux: do not allocate hashtabs dynamically

It is simpler to allocate them statically in the corresponding
structure, avoiding unnecessary kmalloc() calls and pointer
dereferencing.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: manual merging required in policydb.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/ss/hashtab.c

@@ -29,34 +29,21 @@ static u32 hashtab_compute_size(u32 nel)
 	return nel == 0 ? 0 : roundup_pow_of_two(nel);
 }
 
-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 nel_hint)
+int hashtab_init(struct hashtab *h,
+		 u32 (*hash_value)(struct hashtab *h, const void *key),
+		 int (*keycmp)(struct hashtab *h, const void *key1,
+			       const void *key2),
+		 u32 nel_hint)
 {
-	struct hashtab *p;
-	u32 i, size = hashtab_compute_size(nel_hint);
-
-	p = kzalloc(sizeof(*p), GFP_KERNEL);
-	if (!p)
-		return p;
-
-	p->size = size;
-	p->nel = 0;
-	p->hash_value = hash_value;
-	p->keycmp = keycmp;
-	if (!size)
-		return p;
-
-	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;
+	h->size = hashtab_compute_size(nel_hint);
+	h->nel = 0;
+	h->hash_value = hash_value;
+	h->keycmp = keycmp;
+	if (!h->size)
+		return 0;
 
-	return p;
+	h->htable = kcalloc(h->size, sizeof(*h->htable), GFP_KERNEL);
+	return h->htable ? 0 : -ENOMEM;
 }
 
 int hashtab_insert(struct hashtab *h, void *key, void *datum)
@@ -66,7 +53,7 @@ int hashtab_insert(struct hashtab *h, void *key, void *datum)
 
 	cond_resched();
 
-	if (!h || !h->size || h->nel == HASHTAB_MAX_NODES)
+	if (!h->size || h->nel == HASHTAB_MAX_NODES)
 		return -EINVAL;
 
 	hvalue = h->hash_value(h, key);
@@ -102,7 +89,7 @@ void *hashtab_search(struct hashtab *h, const void *key)
 	u32 hvalue;
 	struct hashtab_node *cur;
 
-	if (!h || !h->size)
+	if (!h->size)
 		return NULL;
 
 	hvalue = h->hash_value(h, key);
@@ -121,9 +108,6 @@ 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) {
@@ -136,8 +120,6 @@ void hashtab_destroy(struct hashtab *h)
 
 	kfree(h->htable);
 	h->htable = NULL;
-
-	kfree(h);
 }
 
 int hashtab_map(struct hashtab *h,
@@ -148,9 +130,6 @@ int hashtab_map(struct hashtab *h,
 	int ret;
 	struct hashtab_node *cur;
 
-	if (!h)
-		return 0;
-
 	for (i = 0; i < h->size; i++) {
 		cur = h->htable[i];
 		while (cur) {

security/selinux/ss/hashtab.h

@@ -35,14 +35,15 @@ struct hashtab_info {
 };
 
 /*
- * Creates a new hash table with the specified characteristics.
+ * Initializes a new hash table with the specified characteristics.
  *
- * Returns NULL if insufficent space is available or
- * the new hash table otherwise.
+ * Returns -ENOMEM if insufficient space is available or 0 otherwise.
  */
-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 nel_hint);
+int hashtab_init(struct hashtab *h,
+		 u32 (*hash_value)(struct hashtab *h, const void *key),
+		 int (*keycmp)(struct hashtab *h, const void *key1,
+			       const void *key2),
+		 u32 nel_hint);
 
 /*
  * Inserts the specified (key, datum) pair into the specified hash table.

security/selinux/ss/mls.c

@@ -165,7 +165,7 @@ int mls_level_isvalid(struct policydb *p, struct mls_level *l)
 
 	if (!l->sens || l->sens > p->p_levels.nprim)
 		return 0;
-	levdatum = hashtab_search(p->p_levels.table,
+	levdatum = hashtab_search(&p->p_levels.table,
 				  sym_name(p, SYM_LEVELS, l->sens - 1));
 	if (!levdatum)
 		return 0;
@@ -293,7 +293,7 @@ int mls_context_to_sid(struct policydb *pol,
 			*(next_cat++) = '\0';
 
 		/* Parse sensitivity. */
-		levdatum = hashtab_search(pol->p_levels.table, sensitivity);
+		levdatum = hashtab_search(&pol->p_levels.table, sensitivity);
 		if (!levdatum)
 			return -EINVAL;
 		context->range.level[l].sens = levdatum->level->sens;
@@ -312,7 +312,7 @@ int mls_context_to_sid(struct policydb *pol,
 				*rngptr++ = '\0';
 			}
 
-			catdatum = hashtab_search(pol->p_cats.table, cur_cat);
+			catdatum = hashtab_search(&pol->p_cats.table, cur_cat);
 			if (!catdatum)
 				return -EINVAL;
 
@@ -325,7 +325,7 @@ int mls_context_to_sid(struct policydb *pol,
 			if (rngptr == NULL)
 				continue;
 
-			rngdatum = hashtab_search(pol->p_cats.table, rngptr);
+			rngdatum = hashtab_search(&pol->p_cats.table, rngptr);
 			if (!rngdatum)
 				return -EINVAL;
 
@@ -458,7 +458,7 @@ int mls_convert_context(struct policydb *oldp,
 		return 0;
 
 	for (l = 0; l < 2; l++) {
-		levdatum = hashtab_search(newp->p_levels.table,
+		levdatum = hashtab_search(&newp->p_levels.table,
 					  sym_name(oldp, SYM_LEVELS,
 						   oldc->range.level[l].sens - 1));
 
@@ -470,7 +470,7 @@ int mls_convert_context(struct policydb *oldp,
 					      node, i) {
 			int rc;
 
-			catdatum = hashtab_search(newp->p_cats.table,
+			catdatum = hashtab_search(&newp->p_cats.table,
 						  sym_name(oldp, SYM_CATS, i));
 			if (!catdatum)
 				return -EINVAL;
@@ -506,7 +506,7 @@ int mls_compute_sid(struct policydb *p,
 		rtr.source_type = scontext->type;
 		rtr.target_type = tcontext->type;
 		rtr.target_class = tclass;
-		r = hashtab_search(p->range_tr, &rtr);
+		r = hashtab_search(&p->range_tr, &rtr);
 		if (r)
 			return mls_range_set(newcontext, r);
 

security/selinux/ss/policydb.h

@@ -263,13 +263,13 @@ struct policydb {
 	struct avtab te_avtab;
 
 	/* role transitions */
-	struct hashtab *role_tr;
+	struct hashtab role_tr;
 
 	/* file transitions with the last path component */
 	/* quickly exclude lookups when parent ttype has no rules */
 	struct ebitmap filename_trans_ttypes;
 	/* actual set of filename_trans rules */
-	struct hashtab *filename_trans;
+	struct hashtab filename_trans;
 	/* only used if policyvers < POLICYDB_VERSION_COMP_FTRANS */
 	u32 compat_filename_trans_count;
 
@@ -294,7 +294,7 @@ struct policydb {
 	struct genfs *genfs;
 
 	/* range transitions table (range_trans_key -> mls_range) */
-	struct hashtab *range_tr;
+	struct hashtab range_tr;
 
 	/* type -> attribute reverse mapping */
 	struct ebitmap *type_attr_map_array;

security/selinux/ss/services.c

@@ -482,11 +482,11 @@ static void security_dump_masked_av(struct policydb *policydb,
 
 	/* init permission_names */
 	if (common_dat &&
-	    hashtab_map(common_dat->permissions.table,
+	    hashtab_map(&common_dat->permissions.table,
 			dump_masked_av_helper, permission_names) < 0)
 		goto out;
 
-	if (hashtab_map(tclass_dat->permissions.table,
+	if (hashtab_map(&tclass_dat->permissions.table,
 			dump_masked_av_helper, permission_names) < 0)
 		goto out;
 
@@ -1441,7 +1441,7 @@ static int string_to_context_struct(struct policydb *pol,
 
 	*p++ = 0;
 
-	usrdatum = hashtab_search(pol->p_users.table, scontextp);
+	usrdatum = hashtab_search(&pol->p_users.table, scontextp);
 	if (!usrdatum)
 		goto out;
 
@@ -1457,7 +1457,7 @@ static int string_to_context_struct(struct policydb *pol,
 
 	*p++ = 0;
 
-	role = hashtab_search(pol->p_roles.table, scontextp);
+	role = hashtab_search(&pol->p_roles.table, scontextp);
 	if (!role)
 		goto out;
 	ctx->role = role->value;
@@ -1469,7 +1469,7 @@ static int string_to_context_struct(struct policydb *pol,
 	oldc = *p;
 	*p++ = 0;
 
-	typdatum = hashtab_search(pol->p_types.table, scontextp);
+	typdatum = hashtab_search(&pol->p_types.table, scontextp);
 	if (!typdatum || typdatum->attribute)
 		goto out;
 
@@ -1671,7 +1671,7 @@ static void filename_compute_type(struct policydb *policydb,
 	ft.tclass = tclass;
 	ft.name = objname;
 
-	datum = hashtab_search(policydb->filename_trans, &ft);
+	datum = hashtab_search(&policydb->filename_trans, &ft);
 	while (datum) {
 		if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
 			newcontext->type = datum->otype;
@@ -1834,7 +1834,7 @@ static int security_compute_sid(struct selinux_state *state,
 			.tclass = tclass,
 		};
 
-		rtd = hashtab_search(policydb->role_tr, &rtk);
+		rtd = hashtab_search(&policydb->role_tr, &rtk);
 		if (rtd)
 			newcontext.role = rtd->new_role;
 	}
@@ -2024,7 +2024,7 @@ static int convert_context(struct context *oldc, struct context *newc, void *p)
 
 	/* Convert the user. */
 	rc = -EINVAL;
-	usrdatum = hashtab_search(args->newp->p_users.table,
+	usrdatum = hashtab_search(&args->newp->p_users.table,
 				  sym_name(args->oldp,
 					   SYM_USERS, oldc->user - 1));
 	if (!usrdatum)
@@ -2033,7 +2033,7 @@ static int convert_context(struct context *oldc, struct context *newc, void *p)
 
 	/* Convert the role. */
 	rc = -EINVAL;
-	role = hashtab_search(args->newp->p_roles.table,
+	role = hashtab_search(&args->newp->p_roles.table,
 			      sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
 	if (!role)
 		goto bad;
@@ -2041,7 +2041,7 @@ static int convert_context(struct context *oldc, struct context *newc, void *p)
 
 	/* Convert the type. */
 	rc = -EINVAL;
-	typdatum = hashtab_search(args->newp->p_types.table,
+	typdatum = hashtab_search(&args->newp->p_types.table,
 				  sym_name(args->oldp,
 					   SYM_TYPES, oldc->type - 1));
 	if (!typdatum)
@@ -2623,7 +2623,7 @@ int security_get_user_sids(struct selinux_state *state,
 		goto out_unlock;
 
 	rc = -EINVAL;
-	user = hashtab_search(policydb->p_users.table, username);
+	user = hashtab_search(&policydb->p_users.table, username);
 	if (!user)
 		goto out_unlock;
 
@@ -2975,7 +2975,7 @@ static int security_preserve_bools(struct selinux_state *state,
 	if (rc)
 		goto out;
 	for (i = 0; i < nbools; i++) {
-		booldatum = hashtab_search(policydb->p_bools.table, bnames[i]);
+		booldatum = hashtab_search(&policydb->p_bools.table, bnames[i]);
 		if (booldatum)
 			booldatum->state = bvalues[i];
 	}
@@ -3189,8 +3189,8 @@ int security_get_classes(struct selinux_state *state,
 	if (!*classes)
 		goto out;
 
-	rc = hashtab_map(policydb->p_classes.table, get_classes_callback,
-			*classes);
+	rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
+			 *classes);
 	if (rc) {
 		int i;
 		for (i = 0; i < *nclasses; i++)
@@ -3226,7 +3226,7 @@ int security_get_permissions(struct selinux_state *state,
 	read_lock(&state->ss->policy_rwlock);
 
 	rc = -EINVAL;
-	match = hashtab_search(policydb->p_classes.table, class);
+	match = hashtab_search(&policydb->p_classes.table, class);
 	if (!match) {
 		pr_err("SELinux: %s:  unrecognized class %s\n",
 			__func__, class);
@@ -3240,14 +3240,14 @@ int security_get_permissions(struct selinux_state *state,
 		goto out;
 
 	if (match->comdatum) {
-		rc = hashtab_map(match->comdatum->permissions.table,
-				get_permissions_callback, *perms);
+		rc = hashtab_map(&match->comdatum->permissions.table,
+				 get_permissions_callback, *perms);
 		if (rc)
 			goto err;
 	}
 
-	rc = hashtab_map(match->permissions.table, get_permissions_callback,
-			*perms);
+	rc = hashtab_map(&match->permissions.table, get_permissions_callback,
+			 *perms);
 	if (rc)
 		goto err;
 
@@ -3365,7 +3365,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 	case AUDIT_SUBJ_USER:
 	case AUDIT_OBJ_USER:
 		rc = -EINVAL;
-		userdatum = hashtab_search(policydb->p_users.table, rulestr);
+		userdatum = hashtab_search(&policydb->p_users.table, rulestr);
 		if (!userdatum)
 			goto out;
 		tmprule->au_ctxt.user = userdatum->value;
@@ -3373,7 +3373,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 	case AUDIT_SUBJ_ROLE:
 	case AUDIT_OBJ_ROLE:
 		rc = -EINVAL;
-		roledatum = hashtab_search(policydb->p_roles.table, rulestr);
+		roledatum = hashtab_search(&policydb->p_roles.table, rulestr);
 		if (!roledatum)
 			goto out;
 		tmprule->au_ctxt.role = roledatum->value;
@@ -3381,7 +3381,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 	case AUDIT_SUBJ_TYPE:
 	case AUDIT_OBJ_TYPE:
 		rc = -EINVAL;
-		typedatum = hashtab_search(policydb->p_types.table, rulestr);
+		typedatum = hashtab_search(&policydb->p_types.table, rulestr);
 		if (!typedatum)
 			goto out;
 		tmprule->au_ctxt.type = typedatum->value;

security/selinux/ss/symtab.c

@@ -35,10 +35,7 @@ static int symcmp(struct hashtab *h, const void *key1, const void *key2)
 
 int symtab_init(struct symtab *s, unsigned int size)
 {
-	s->table = hashtab_create(symhash, symcmp, size);
-	if (!s->table)
-		return -ENOMEM;
 	s->nprim = 0;
-	return 0;
+	return hashtab_init(&s->table, symhash, symcmp, size);
 }
 

security/selinux/ss/symtab.h

@@ -13,7 +13,7 @@
 #include "hashtab.h"
 
 struct symtab {
-	struct hashtab *table;	/* hash table (keyed on a string) */
+	struct hashtab table;	/* hash table (keyed on a string) */
 	u32 nprim;		/* number of primary names in table */
 };