5 files changed, 244 insertions, 235 deletions

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 624ccc6ac744..1260f5fb766e 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -177,6 +177,195 @@ static struct policydb_compat_info *policydb_lookup_compat(int version)
 }
 
 /*
+ * The following *_destroy functions are used to
+ * free any memory allocated for each kind of
+ * symbol data in the policy database.
+ */
+
+static int perm_destroy(void *key, void *datum, void *p)
+{
+	kfree(key);
+	kfree(datum);
+	return 0;
+}
+
+static int common_destroy(void *key, void *datum, void *p)
+{
+	struct common_datum *comdatum;
+
+	kfree(key);
+	if (datum) {
+		comdatum = datum;
+		hashtab_map(comdatum->permissions.table, perm_destroy, NULL);
+		hashtab_destroy(comdatum->permissions.table);
+	}
+	kfree(datum);
+	return 0;
+}
+
+static void constraint_expr_destroy(struct constraint_expr *expr)
+{
+	if (expr) {
+		ebitmap_destroy(&expr->names);
+		if (expr->type_names) {
+			ebitmap_destroy(&expr->type_names->types);
+			ebitmap_destroy(&expr->type_names->negset);
+			kfree(expr->type_names);
+		}
+		kfree(expr);
+	}
+}
+
+static int cls_destroy(void *key, void *datum, void *p)
+{
+	struct class_datum *cladatum;
+	struct constraint_node *constraint, *ctemp;
+	struct constraint_expr *e, *etmp;
+
+	kfree(key);
+	if (datum) {
+		cladatum = datum;
+		hashtab_map(cladatum->permissions.table, perm_destroy, NULL);
+		hashtab_destroy(cladatum->permissions.table);
+		constraint = cladatum->constraints;
+		while (constraint) {
+			e = constraint->expr;
+			while (e) {
+				etmp = e;
+				e = e->next;
+				constraint_expr_destroy(etmp);
+			}
+			ctemp = constraint;
+			constraint = constraint->next;
+			kfree(ctemp);
+		}
+
+		constraint = cladatum->validatetrans;
+		while (constraint) {
+			e = constraint->expr;
+			while (e) {
+				etmp = e;
+				e = e->next;
+				constraint_expr_destroy(etmp);
+			}
+			ctemp = constraint;
+			constraint = constraint->next;
+			kfree(ctemp);
+		}
+		kfree(cladatum->comkey);
+	}
+	kfree(datum);
+	return 0;
+}
+
+static int role_destroy(void *key, void *datum, void *p)
+{
+	struct role_datum *role;
+
+	kfree(key);
+	if (datum) {
+		role = datum;
+		ebitmap_destroy(&role->dominates);
+		ebitmap_destroy(&role->types);
+	}
+	kfree(datum);
+	return 0;
+}
+
+static int type_destroy(void *key, void *datum, void *p)
+{
+	kfree(key);
+	kfree(datum);
+	return 0;
+}
+
+static int user_destroy(void *key, void *datum, void *p)
+{
+	struct user_datum *usrdatum;
+
+	kfree(key);
+	if (datum) {
+		usrdatum = datum;
+		ebitmap_destroy(&usrdatum->roles);
+		ebitmap_destroy(&usrdatum->range.level[0].cat);
+		ebitmap_destroy(&usrdatum->range.level[1].cat);
+		ebitmap_destroy(&usrdatum->dfltlevel.cat);
+	}
+	kfree(datum);
+	return 0;
+}
+
+static int sens_destroy(void *key, void *datum, void *p)
+{
+	struct level_datum *levdatum;
+
+	kfree(key);
+	if (datum) {
+		levdatum = datum;
+		if (levdatum->level)
+			ebitmap_destroy(&levdatum->level->cat);
+		kfree(levdatum->level);
+	}
+	kfree(datum);
+	return 0;
+}
+
+static int cat_destroy(void *key, void *datum, void *p)
+{
+	kfree(key);
+	kfree(datum);
+	return 0;
+}
+
+static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) =
+{
+	common_destroy,
+	cls_destroy,
+	role_destroy,
+	type_destroy,
+	user_destroy,
+	cond_destroy_bool,
+	sens_destroy,
+	cat_destroy,
+};
+
+static int filenametr_destroy(void *key, void *datum, void *p)
+{
+	struct filename_trans *ft = key;
+
+	kfree(ft->name);
+	kfree(key);
+	kfree(datum);
+	cond_resched();
+	return 0;
+}
+
+static int range_tr_destroy(void *key, void *datum, void *p)
+{
+	struct mls_range *rt = datum;
+
+	kfree(key);
+	ebitmap_destroy(&rt->level[0].cat);
+	ebitmap_destroy(&rt->level[1].cat);
+	kfree(datum);
+	cond_resched();
+	return 0;
+}
+
+static void ocontext_destroy(struct ocontext *c, int i)
+{
+	if (!c)
+		return;
+
+	context_destroy(&c->context[0]);
+	context_destroy(&c->context[1]);
+	if (i == OCON_ISID || i == OCON_FS ||
+	    i == OCON_NETIF || i == OCON_FSUSE)
+		kfree(c->u.name);
+	kfree(c);
+}
+
+/*
  * Initialize the role table.
  */
 static int roles_init(struct policydb *p)
@@ -250,6 +439,7 @@ static int filenametr_cmp(struct hashtab *h, const void *k1, const void *k2)
 static u32 rangetr_hash(struct hashtab *h, const void *k)
 {
 	const struct range_trans *key = k;
+
 	return (key->source_type + (key->target_type << 3) +
 		(key->target_class << 5)) & (h->size - 1);
 }
@@ -299,7 +489,8 @@ static int policydb_init(struct policydb *p)
 	if (rc)
 		goto out;
 
-	p->filename_trans = hashtab_create(filenametr_hash, filenametr_cmp, (1 << 10));
+	p->filename_trans = hashtab_create(filenametr_hash, filenametr_cmp,
+					   (1 << 10));
 	if (!p->filename_trans) {
 		rc = -ENOMEM;
 		goto out;
@@ -319,8 +510,10 @@ static int policydb_init(struct policydb *p)
 out:
 	hashtab_destroy(p->filename_trans);
 	hashtab_destroy(p->range_tr);
-	for (i = 0; i < SYM_NUM; i++)
+	for (i = 0; i < SYM_NUM; i++) {
+		hashtab_map(p->symtab[i].table, destroy_f[i], NULL);
 		hashtab_destroy(p->symtab[i].table);
+	}
 	return rc;
 }
 
@@ -395,7 +588,7 @@ static int type_index(void *key, void *datum, void *datap)
 		    || typdatum->bounds > p->p_types.nprim)
 			return -EINVAL;
 		p->sym_val_to_name[SYM_TYPES][typdatum->value - 1] = key;
-		p->type_val_to_struct_array[typdatum->value - 1] = typdatum;
+		p->type_val_to_struct[typdatum->value - 1] = typdatum;
 	}
 
 	return 0;
@@ -473,9 +666,9 @@ static void hash_eval(struct hashtab *h, const char *hash_name)
 	struct hashtab_info info;
 
 	hashtab_stat(h, &info);
-	pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, "
-	       "longest chain length %d\n", hash_name, h->nel,
-	       info.slots_used, h->size, info.max_chain_len);
+	pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, longest chain length %d\n",
+		 hash_name, h->nel, info.slots_used, h->size,
+		 info.max_chain_len);
 }
 
 static void symtab_hash_eval(struct symtab *s)
@@ -537,10 +730,10 @@ static int policydb_index(struct policydb *p)
 	if (!p->user_val_to_struct)
 		return -ENOMEM;
 
-	p->type_val_to_struct_array = kvcalloc(p->p_types.nprim,
-					       sizeof(*p->type_val_to_struct_array),
-					       GFP_KERNEL);
-	if (!p->type_val_to_struct_array)
+	p->type_val_to_struct = kvcalloc(p->p_types.nprim,
+					 sizeof(*p->type_val_to_struct),
+					 GFP_KERNEL);
+	if (!p->type_val_to_struct)
 		return -ENOMEM;
 
 	rc = cond_init_bool_indexes(p);
@@ -564,193 +757,6 @@ out:
 }
 
 /*
- * The following *_destroy functions are used to
- * free any memory allocated for each kind of
- * symbol data in the policy database.
- */
-
-static int perm_destroy(void *key, void *datum, void *p)
-{
-	kfree(key);
-	kfree(datum);
-	return 0;
-}
-
-static int common_destroy(void *key, void *datum, void *p)
-{
-	struct common_datum *comdatum;
-
-	kfree(key);
-	if (datum) {
-		comdatum = datum;
-		hashtab_map(comdatum->permissions.table, perm_destroy, NULL);
-		hashtab_destroy(comdatum->permissions.table);
-	}
-	kfree(datum);
-	return 0;
-}
-
-static void constraint_expr_destroy(struct constraint_expr *expr)
-{
-	if (expr) {
-		ebitmap_destroy(&expr->names);
-		if (expr->type_names) {
-			ebitmap_destroy(&expr->type_names->types);
-			ebitmap_destroy(&expr->type_names->negset);
-			kfree(expr->type_names);
-		}
-		kfree(expr);
-	}
-}
-
-static int cls_destroy(void *key, void *datum, void *p)
-{
-	struct class_datum *cladatum;
-	struct constraint_node *constraint, *ctemp;
-	struct constraint_expr *e, *etmp;
-
-	kfree(key);
-	if (datum) {
-		cladatum = datum;
-		hashtab_map(cladatum->permissions.table, perm_destroy, NULL);
-		hashtab_destroy(cladatum->permissions.table);
-		constraint = cladatum->constraints;
-		while (constraint) {
-			e = constraint->expr;
-			while (e) {
-				etmp = e;
-				e = e->next;
-				constraint_expr_destroy(etmp);
-			}
-			ctemp = constraint;
-			constraint = constraint->next;
-			kfree(ctemp);
-		}
-
-		constraint = cladatum->validatetrans;
-		while (constraint) {
-			e = constraint->expr;
-			while (e) {
-				etmp = e;
-				e = e->next;
-				constraint_expr_destroy(etmp);
-			}
-			ctemp = constraint;
-			constraint = constraint->next;
-			kfree(ctemp);
-		}
-		kfree(cladatum->comkey);
-	}
-	kfree(datum);
-	return 0;
-}
-
-static int role_destroy(void *key, void *datum, void *p)
-{
-	struct role_datum *role;
-
-	kfree(key);
-	if (datum) {
-		role = datum;
-		ebitmap_destroy(&role->dominates);
-		ebitmap_destroy(&role->types);
-	}
-	kfree(datum);
-	return 0;
-}
-
-static int type_destroy(void *key, void *datum, void *p)
-{
-	kfree(key);
-	kfree(datum);
-	return 0;
-}
-
-static int user_destroy(void *key, void *datum, void *p)
-{
-	struct user_datum *usrdatum;
-
-	kfree(key);
-	if (datum) {
-		usrdatum = datum;
-		ebitmap_destroy(&usrdatum->roles);
-		ebitmap_destroy(&usrdatum->range.level[0].cat);
-		ebitmap_destroy(&usrdatum->range.level[1].cat);
-		ebitmap_destroy(&usrdatum->dfltlevel.cat);
-	}
-	kfree(datum);
-	return 0;
-}
-
-static int sens_destroy(void *key, void *datum, void *p)
-{
-	struct level_datum *levdatum;
-
-	kfree(key);
-	if (datum) {
-		levdatum = datum;
-		if (levdatum->level)
-			ebitmap_destroy(&levdatum->level->cat);
-		kfree(levdatum->level);
-	}
-	kfree(datum);
-	return 0;
-}
-
-static int cat_destroy(void *key, void *datum, void *p)
-{
-	kfree(key);
-	kfree(datum);
-	return 0;
-}
-
-static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) =
-{
-	common_destroy,
-	cls_destroy,
-	role_destroy,
-	type_destroy,
-	user_destroy,
-	cond_destroy_bool,
-	sens_destroy,
-	cat_destroy,
-};
-
-static int filenametr_destroy(void *key, void *datum, void *p)
-{
-	struct filename_trans *ft = key;
-	kfree(ft->name);
-	kfree(key);
-	kfree(datum);
-	cond_resched();
-	return 0;
-}
-
-static int range_tr_destroy(void *key, void *datum, void *p)
-{
-	struct mls_range *rt = datum;
-	kfree(key);
-	ebitmap_destroy(&rt->level[0].cat);
-	ebitmap_destroy(&rt->level[1].cat);
-	kfree(datum);
-	cond_resched();
-	return 0;
-}
-
-static void ocontext_destroy(struct ocontext *c, int i)
-{
-	if (!c)
-		return;
-
-	context_destroy(&c->context[0]);
-	context_destroy(&c->context[1]);
-	if (i == OCON_ISID || i == OCON_FS ||
-	    i == OCON_NETIF || i == OCON_FSUSE)
-		kfree(c->u.name);
-	kfree(c);
-}
-
-/*
  * Free any memory allocated by a policy database structure.
  */
 void policydb_destroy(struct policydb *p)
@@ -773,7 +779,7 @@ void policydb_destroy(struct policydb *p)
 	kfree(p->class_val_to_struct);
 	kfree(p->role_val_to_struct);
 	kfree(p->user_val_to_struct);
-	kvfree(p->type_val_to_struct_array);
+	kvfree(p->type_val_to_struct);
 
 	avtab_destroy(&p->te_avtab);
 
@@ -1718,7 +1724,7 @@ static int type_bounds_sanity_check(void *key, void *datum, void *datap)
 			return -EINVAL;
 		}
 
-		upper = p->type_val_to_struct_array[upper->bounds - 1];
+		upper = p->type_val_to_struct[upper->bounds - 1];
 		BUG_ON(!upper);
 
 		if (upper->attribute) {
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index fcc6366b447f..162d0e79b85b 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -253,7 +253,7 @@ struct policydb {
 	struct class_datum **class_val_to_struct;
 	struct role_datum **role_val_to_struct;
 	struct user_datum **user_val_to_struct;
-	struct type_datum **type_val_to_struct_array;
+	struct type_datum **type_val_to_struct;
 
 	/* type enforcement access vectors and transitions */
 	struct avtab te_avtab;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index d61563a3695e..3a29e7c24ba9 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -542,13 +542,13 @@ static void type_attribute_bounds_av(struct policydb *policydb,
 	struct type_datum *target;
 	u32 masked = 0;
 
-	source = policydb->type_val_to_struct_array[scontext->type - 1];
+	source = policydb->type_val_to_struct[scontext->type - 1];
 	BUG_ON(!source);
 
 	if (!source->bounds)
 		return;
 
-	target = policydb->type_val_to_struct_array[tcontext->type - 1];
+	target = policydb->type_val_to_struct[tcontext->type - 1];
 	BUG_ON(!target);
 
 	memset(&lo_avd, 0, sizeof(lo_avd));
@@ -891,7 +891,7 @@ int security_bounded_transition(struct selinux_state *state,
 
 	index = new_context->type;
 	while (true) {
-		type = policydb->type_val_to_struct_array[index - 1];
+		type = policydb->type_val_to_struct[index - 1];
 		BUG_ON(!type);
 
 		/* not bounded anymore */
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index 1f0a6eaa2d6a..7d49994e8d5f 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -12,7 +12,7 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
-#include <linux/atomic.h>
+#include <asm/barrier.h>
 #include "flask.h"
 #include "security.h"
 #include "sidtab.h"
@@ -23,14 +23,14 @@ int sidtab_init(struct sidtab *s)
 
 	memset(s->roots, 0, sizeof(s->roots));
 
+	/* max count is SIDTAB_MAX so valid index is always < SIDTAB_MAX */
 	for (i = 0; i < SIDTAB_RCACHE_SIZE; i++)
-		atomic_set(&s->rcache[i], -1);
+		s->rcache[i] = SIDTAB_MAX;
 
 	for (i = 0; i < SECINITSID_NUM; i++)
 		s->isids[i].set = 0;
 
-	atomic_set(&s->count, 0);
-
+	s->count = 0;
 	s->convert = NULL;
 
 	spin_lock_init(&s->lock);
@@ -130,14 +130,12 @@ static struct context *sidtab_do_lookup(struct sidtab *s, u32 index, int alloc)
 
 static struct context *sidtab_lookup(struct sidtab *s, u32 index)
 {
-	u32 count = (u32)atomic_read(&s->count);
+	/* read entries only after reading count */
+	u32 count = smp_load_acquire(&s->count);
 
 	if (index >= count)
 		return NULL;
 
-	/* read entries after reading count */
-	smp_rmb();
-
 	return sidtab_do_lookup(s, index, 0);
 }
 
@@ -210,10 +208,10 @@ static int sidtab_find_context(union sidtab_entry_inner entry,
 static void sidtab_rcache_update(struct sidtab *s, u32 index, u32 pos)
 {
 	while (pos > 0) {
-		atomic_set(&s->rcache[pos], atomic_read(&s->rcache[pos - 1]));
+		WRITE_ONCE(s->rcache[pos], READ_ONCE(s->rcache[pos - 1]));
 		--pos;
 	}
-	atomic_set(&s->rcache[0], (int)index);
+	WRITE_ONCE(s->rcache[0], index);
 }
 
 static void sidtab_rcache_push(struct sidtab *s, u32 index)
@@ -227,14 +225,14 @@ static int sidtab_rcache_search(struct sidtab *s, struct context *context,
 	u32 i;
 
 	for (i = 0; i < SIDTAB_RCACHE_SIZE; i++) {
-		int v = atomic_read(&s->rcache[i]);
+		u32 v = READ_ONCE(s->rcache[i]);
 
-		if (v < 0)
+		if (v >= SIDTAB_MAX)
 			continue;
 
-		if (context_cmp(sidtab_do_lookup(s, (u32)v, 0), context)) {
-			sidtab_rcache_update(s, (u32)v, i);
-			*index = (u32)v;
+		if (context_cmp(sidtab_do_lookup(s, v, 0), context)) {
+			sidtab_rcache_update(s, v, i);
+			*index = v;
 			return 0;
 		}
 	}
@@ -245,8 +243,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
 				 u32 *index)
 {
 	unsigned long flags;
-	u32 count = (u32)atomic_read(&s->count);
-	u32 count_locked, level, pos;
+	u32 count, count_locked, level, pos;
 	struct sidtab_convert_params *convert;
 	struct context *dst, *dst_convert;
 	int rc;
@@ -255,11 +252,10 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
 	if (rc == 0)
 		return 0;
 
+	/* read entries only after reading count */
+	count = smp_load_acquire(&s->count);
 	level = sidtab_level_from_count(count);
 
-	/* read entries after reading count */
-	smp_rmb();
-
 	pos = 0;
 	rc = sidtab_find_context(s->roots[level], &pos, count, level,
 				 context, index);
@@ -272,7 +268,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
 	spin_lock_irqsave(&s->lock, flags);
 
 	convert = s->convert;
-	count_locked = (u32)atomic_read(&s->count);
+	count_locked = s->count;
 	level = sidtab_level_from_count(count_locked);
 
 	/* if count has changed before we acquired the lock, then catch up */
@@ -320,7 +316,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
 		}
 
 		/* at this point we know the insert won't fail */
-		atomic_set(&convert->target->count, count + 1);
+		convert->target->count = count + 1;
 	}
 
 	if (context->len)
@@ -331,9 +327,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
 	*index = count;
 
 	/* write entries before writing new count */
-	smp_wmb();
-
-	atomic_set(&s->count, count + 1);
+	smp_store_release(&s->count, count + 1);
 
 	rc = 0;
 out_unlock:
@@ -423,7 +417,7 @@ int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params)
 		return -EBUSY;
 	}
 
-	count = (u32)atomic_read(&s->count);
+	count = s->count;
 	level = sidtab_level_from_count(count);
 
 	/* allocate last leaf in the new sidtab (to avoid race with
@@ -436,7 +430,7 @@ int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params)
 	}
 
 	/* set count in case no new entries are added during conversion */
-	atomic_set(&params->target->count, count);
+	params->target->count = count;
 
 	/* enable live convert of new entries */
 	s->convert = params;
diff --git a/security/selinux/ss/sidtab.h b/security/selinux/ss/sidtab.h
index bbd5c0d1f3bd..1f4763141aa1 100644
--- a/security/selinux/ss/sidtab.h
+++ b/security/selinux/ss/sidtab.h
@@ -40,8 +40,8 @@ union sidtab_entry_inner {
 #define SIDTAB_LEAF_ENTRIES \
 	(SIDTAB_NODE_ALLOC_SIZE / sizeof(struct sidtab_entry_leaf))
 
-#define SIDTAB_MAX_BITS 31 /* limited to INT_MAX due to atomic_t range */
-#define SIDTAB_MAX (((u32)1 << SIDTAB_MAX_BITS) - 1)
+#define SIDTAB_MAX_BITS 32
+#define SIDTAB_MAX U32_MAX
 /* ensure enough tree levels for SIDTAB_MAX entries */
 #define SIDTAB_MAX_LEVEL \
 	DIV_ROUND_UP(SIDTAB_MAX_BITS - size_to_shift(SIDTAB_LEAF_ENTRIES), \
@@ -69,13 +69,22 @@ struct sidtab_convert_params {
 #define SIDTAB_RCACHE_SIZE 3
 
 struct sidtab {
+	/*
+	 * lock-free read access only for as many items as a prior read of
+	 * 'count'
+	 */
 	union sidtab_entry_inner roots[SIDTAB_MAX_LEVEL + 1];
-	atomic_t count;
+	/*
+	 * access atomically via {READ|WRITE}_ONCE(); only increment under
+	 * spinlock
+	 */
+	u32 count;
+	/* access only under spinlock */
 	struct sidtab_convert_params *convert;
 	spinlock_t lock;
 
-	/* reverse lookup cache */
-	atomic_t rcache[SIDTAB_RCACHE_SIZE];
+	/* reverse lookup cache - access atomically via {READ|WRITE}_ONCE() */
+	u32 rcache[SIDTAB_RCACHE_SIZE];
 
 	/* index == SID - 1 (no entry for SECSID_NULL) */
 	struct sidtab_isid_entry isids[SECINITSID_NUM];