selinux: convert cond_list to array

Since it is fixed-size after allocation and we know the size beforehand,
using a plain old array is simpler and more efficient.

While there, also fix signedness of some related variables/parameters.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/include/conditional.h

@@ -14,12 +14,10 @@
 #include "security.h"
 
 int security_get_bools(struct selinux_state *state,
-		       int *len, char ***names, int **values);
+		       u32 *len, char ***names, int **values);
 
-int security_set_bools(struct selinux_state *state,
-		       int len, int *values);
+int security_set_bools(struct selinux_state *state, u32 len, int *values);
 
-int security_get_bool_value(struct selinux_state *state,
-			    int index);
+int security_get_bool_value(struct selinux_state *state, u32 index);
 
 #endif

security/selinux/selinuxfs.c

@@ -1335,14 +1335,14 @@ static void sel_remove_entries(struct dentry *de)
 
 static int sel_make_bools(struct selinux_fs_info *fsi)
 {
-	int i, ret;
+	int ret;
 	ssize_t len;
 	struct dentry *dentry = NULL;
 	struct dentry *dir = fsi->bool_dir;
 	struct inode *inode = NULL;
 	struct inode_security_struct *isec;
 	char **names = NULL, *page;
-	int num;
+	u32 i, num;
 	int *values = NULL;
 	u32 sid;
 

security/selinux/ss/conditional.c

@@ -119,6 +119,7 @@ int cond_policydb_init(struct policydb *p)
 
 	p->bool_val_to_struct = NULL;
 	p->cond_list = NULL;
+	p->cond_list_len = 0;
 
 	rc = avtab_init(&p->te_cond_avtab);
 	if (rc)
@@ -147,27 +148,22 @@ static void cond_node_destroy(struct cond_node *node)
 	}
 	cond_av_list_destroy(node->true_list);
 	cond_av_list_destroy(node->false_list);
-	kfree(node);
 }
 
-static void cond_list_destroy(struct cond_node *list)
+static void cond_list_destroy(struct policydb *p)
 {
-	struct cond_node *next, *cur;
+	u32 i;
 
-	if (list == NULL)
-		return;
-
-	for (cur = list; cur; cur = next) {
-		next = cur->next;
-		cond_node_destroy(cur);
-	}
+	for (i = 0; i < p->cond_list_len; i++)
+		cond_node_destroy(&p->cond_list[i]);
+	kfree(p->cond_list);
 }
 
 void cond_policydb_destroy(struct policydb *p)
 {
 	kfree(p->bool_val_to_struct);
 	avtab_destroy(&p->te_cond_avtab);
-	cond_list_destroy(p->cond_list);
+	cond_list_destroy(p);
 }
 
 int cond_init_bool_indexes(struct policydb *p)
@@ -447,7 +443,6 @@ static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
 
 int cond_read_list(struct policydb *p, void *fp)
 {
-	struct cond_node *node, *last = NULL;
 	__le32 buf[1];
 	u32 i, len;
 	int rc;
@@ -458,29 +453,24 @@ int cond_read_list(struct policydb *p, void *fp)
 
 	len = le32_to_cpu(buf[0]);
 
+	p->cond_list = kcalloc(len, sizeof(*p->cond_list), GFP_KERNEL);
+	if (!p->cond_list)
+		return rc;
+
 	rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel);
 	if (rc)
 		goto err;
 
-	for (i = 0; i < len; i++) {
-		rc = -ENOMEM;
-		node = kzalloc(sizeof(*node), GFP_KERNEL);
-		if (!node)
-			goto err;
+	p->cond_list_len = len;
 
-		rc = cond_read_node(p, node, fp);
+	for (i = 0; i < len; i++) {
+		rc = cond_read_node(p, &p->cond_list[i], fp);
 		if (rc)
 			goto err;
-
-		if (i == 0)
-			p->cond_list = node;
-		else
-			last->next = node;
-		last = node;
 	}
 	return 0;
 err:
-	cond_list_destroy(p->cond_list);
+	cond_list_destroy(p);
 	p->cond_list = NULL;
 	return rc;
 }
@@ -585,23 +575,19 @@ static int cond_write_node(struct policydb *p, struct cond_node *node,
 	return 0;
 }
 
-int cond_write_list(struct policydb *p, struct cond_node *list, void *fp)
+int cond_write_list(struct policydb *p, void *fp)
 {
-	struct cond_node *cur;
-	u32 len;
+	u32 i;
 	__le32 buf[1];
 	int rc;
 
-	len = 0;
-	for (cur = list; cur != NULL; cur = cur->next)
-		len++;
-	buf[0] = cpu_to_le32(len);
+	buf[0] = cpu_to_le32(p->cond_list_len);
 	rc = put_entry(buf, sizeof(u32), 1, fp);
 	if (rc)
 		return rc;
 
-	for (cur = list; cur != NULL; cur = cur->next) {
-		rc = cond_write_node(p, cur, fp);
+	for (i = 0; i < p->cond_list_len; i++) {
+		rc = cond_write_node(p, &p->cond_list[i], fp);
 		if (rc)
 			return rc;
 	}

security/selinux/ss/conditional.h

@@ -55,7 +55,6 @@ struct cond_node {
 	struct cond_expr *expr;
 	struct cond_av_list *true_list;
 	struct cond_av_list *false_list;
-	struct cond_node *next;
 };
 
 int cond_policydb_init(struct policydb *p);
@@ -69,7 +68,7 @@ int cond_index_bool(void *key, void *datum, void *datap);
 int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp);
 int cond_read_list(struct policydb *p, void *fp);
 int cond_write_bool(void *key, void *datum, void *ptr);
-int cond_write_list(struct policydb *p, struct cond_node *list, void *fp);
+int cond_write_list(struct policydb *p, void *fp);
 
 void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
 		struct av_decision *avd, struct extended_perms *xperms);

security/selinux/ss/policydb.c

@@ -3483,7 +3483,7 @@ int policydb_write(struct policydb *p, void *fp)
 	if (rc)
 		return rc;
 
-	rc = cond_write_list(p, p->cond_list, fp);
+	rc = cond_write_list(p, fp);
 	if (rc)
 		return rc;
 

security/selinux/ss/policydb.h

@@ -272,8 +272,9 @@ struct policydb {
 	struct cond_bool_datum **bool_val_to_struct;
 	/* type enforcement conditional access vectors and transitions */
 	struct avtab te_cond_avtab;
-	/* linked list indexing te_cond_avtab by conditional */
+	/* array indexing te_cond_avtab by conditional */
 	struct cond_node *cond_list;
+	u32 cond_list_len;
 
 	/* role allows */
 	struct role_allow *role_allow;

security/selinux/ss/services.c

@@ -2867,10 +2867,11 @@ int security_fs_use(struct selinux_state *state, struct super_block *sb)
 }
 
 int security_get_bools(struct selinux_state *state,
-		       int *len, char ***names, int **values)
+		       u32 *len, char ***names, int **values)
 {
 	struct policydb *policydb;
-	int i, rc;
+	u32 i;
+	int rc;
 
 	if (!selinux_initialized(state)) {
 		*len = 0;
@@ -2924,12 +2925,11 @@ int security_get_bools(struct selinux_state *state,
 }
 
 
-int security_set_bools(struct selinux_state *state, int len, int *values)
+int security_set_bools(struct selinux_state *state, u32 len, int *values)
 {
 	struct policydb *policydb;
-	int i, rc;
-	int lenp, seqno = 0;
-	struct cond_node *cur;
+	int rc;
+	u32 i, lenp, seqno = 0;
 
 	write_lock_irq(&state->ss->policy_rwlock);
 
@@ -2957,8 +2957,8 @@ int security_set_bools(struct selinux_state *state, int len, int *values)
 			policydb->bool_val_to_struct[i]->state = 0;
 	}
 
-	for (cur = policydb->cond_list; cur; cur = cur->next)
-		evaluate_cond_node(policydb, cur);
+	for (i = 0; i < policydb->cond_list_len; i++)
+		evaluate_cond_node(policydb, &policydb->cond_list[i]);
 
 	seqno = ++state->ss->latest_granting;
 	rc = 0;
@@ -2974,11 +2974,11 @@ int security_set_bools(struct selinux_state *state, int len, int *values)
 }
 
 int security_get_bool_value(struct selinux_state *state,
-			    int index)
+			    u32 index)
 {
 	struct policydb *policydb;
 	int rc;
-	int len;
+	u32 len;
 
 	read_lock(&state->ss->policy_rwlock);
 
@@ -2998,10 +2998,10 @@ int security_get_bool_value(struct selinux_state *state,
 static int security_preserve_bools(struct selinux_state *state,
 				   struct policydb *policydb)
 {
-	int rc, nbools = 0, *bvalues = NULL, i;
+	int rc, *bvalues = NULL;
 	char **bnames = NULL;
 	struct cond_bool_datum *booldatum;
-	struct cond_node *cur;
+	u32 i, nbools = 0;
 
 	rc = security_get_bools(state, &nbools, &bnames, &bvalues);
 	if (rc)
@@ -3011,8 +3011,8 @@ static int security_preserve_bools(struct selinux_state *state,
 		if (booldatum)
 			booldatum->state = bvalues[i];
 	}
-	for (cur = policydb->cond_list; cur; cur = cur->next)
-		evaluate_cond_node(policydb, cur);
+	for (i = 0; i < policydb->cond_list_len; i++)
+		evaluate_cond_node(policydb, &policydb->cond_list[i]);
 
 out:
 	if (bnames) {