selinux: declare read-only parameters const

Declare ebitmap, mls_level and mls_context parameters const where they
are only read from.  This allows callers to supply pointers to const
as arguments and increases readability.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/ss/context.h

@@ -38,7 +38,7 @@ static inline void mls_context_init(struct context *c)
 	memset(&c->range, 0, sizeof(c->range));
 }
 
-static inline int mls_context_cpy(struct context *dst, struct context *src)
+static inline int mls_context_cpy(struct context *dst, const struct context *src)
 {
 	int rc;
 
@@ -58,7 +58,7 @@ static inline int mls_context_cpy(struct context *dst, struct context *src)
 /*
  * Sets both levels in the MLS range of 'dst' to the low level of 'src'.
  */
-static inline int mls_context_cpy_low(struct context *dst, struct context *src)
+static inline int mls_context_cpy_low(struct context *dst, const struct context *src)
 {
 	int rc;
 
@@ -78,7 +78,7 @@ static inline int mls_context_cpy_low(struct context *dst, struct context *src)
 /*
  * Sets both levels in the MLS range of 'dst' to the high level of 'src'.
  */
-static inline int mls_context_cpy_high(struct context *dst, struct context *src)
+static inline int mls_context_cpy_high(struct context *dst, const struct context *src)
 {
 	int rc;
 
@@ -97,9 +97,10 @@ static inline int mls_context_cpy_high(struct context *dst, struct context *src)
 
 
 static inline int mls_context_glblub(struct context *dst,
-				     struct context *c1, struct context *c2)
+				     const struct context *c1, const struct context *c2)
 {
-	struct mls_range *dr = &dst->range, *r1 = &c1->range, *r2 = &c2->range;
+	struct mls_range *dr = &dst->range;
+	const struct mls_range *r1 = &c1->range, *r2 = &c2->range;
 	int rc = 0;
 
 	if (r1->level[1].sens < r2->level[0].sens ||
@@ -127,7 +128,7 @@ static inline int mls_context_glblub(struct context *dst,
 	return rc;
 }
 
-static inline int mls_context_cmp(struct context *c1, struct context *c2)
+static inline int mls_context_cmp(const struct context *c1, const struct context *c2)
 {
 	return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
 		ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
@@ -147,7 +148,7 @@ static inline void context_init(struct context *c)
 	memset(c, 0, sizeof(*c));
 }
 
-static inline int context_cpy(struct context *dst, struct context *src)
+static inline int context_cpy(struct context *dst, const struct context *src)
 {
 	int rc;
 
@@ -180,7 +181,7 @@ static inline void context_destroy(struct context *c)
 	mls_context_destroy(c);
 }
 
-static inline int context_cmp(struct context *c1, struct context *c2)
+static inline int context_cmp(const struct context *c1, const struct context *c2)
 {
 	if (c1->len && c2->len)
 		return (c1->len == c2->len && !strcmp(c1->str, c2->str));

security/selinux/ss/ebitmap.c

@@ -28,9 +28,9 @@
 
 static struct kmem_cache *ebitmap_node_cachep __ro_after_init;
 
-int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
+int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2)
 {
-	struct ebitmap_node *n1, *n2;
+	const struct ebitmap_node *n1, *n2;
 
 	if (e1->highbit != e2->highbit)
 		return 0;
@@ -50,9 +50,10 @@ int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
 	return 1;
 }
 
-int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src)
+int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src)
 {
-	struct ebitmap_node *n, *new, *prev;
+	struct ebitmap_node *new, *prev;
+	const struct ebitmap_node *n;
 
 	ebitmap_init(dst);
 	n = src->node;
@@ -78,7 +79,7 @@ int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src)
 	return 0;
 }
 
-int ebitmap_and(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2)
+int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, const struct ebitmap *e2)
 {
 	struct ebitmap_node *n;
 	int bit, rc;
@@ -217,9 +218,9 @@ int ebitmap_netlbl_import(struct ebitmap *ebmap,
  * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
  * last_e2bit.
  */
-int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
+int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, u32 last_e2bit)
 {
-	struct ebitmap_node *n1, *n2;
+	const struct ebitmap_node *n1, *n2;
 	int i;
 
 	if (e1->highbit < e2->highbit)
@@ -258,9 +259,9 @@ int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
 	return 1;
 }
 
-int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
+int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit)
 {
-	struct ebitmap_node *n;
+	const struct ebitmap_node *n;
 
 	if (e->highbit < bit)
 		return 0;
@@ -467,7 +468,7 @@ int ebitmap_read(struct ebitmap *e, void *fp)
 	goto out;
 }
 
-int ebitmap_write(struct ebitmap *e, void *fp)
+int ebitmap_write(const struct ebitmap *e, void *fp)
 {
 	struct ebitmap_node *n;
 	u32 count;

security/selinux/ss/ebitmap.h

@@ -44,7 +44,7 @@ struct ebitmap {
 
 #define ebitmap_length(e) ((e)->highbit)
 
-static inline unsigned int ebitmap_start_positive(struct ebitmap *e,
+static inline unsigned int ebitmap_start_positive(const struct ebitmap *e,
 						  struct ebitmap_node **n)
 {
 	unsigned int ofs;
@@ -62,7 +62,7 @@ static inline void ebitmap_init(struct ebitmap *e)
 	memset(e, 0, sizeof(*e));
 }
 
-static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
+static inline unsigned int ebitmap_next_positive(const struct ebitmap *e,
 						 struct ebitmap_node **n,
 						 unsigned int bit)
 {
@@ -85,7 +85,7 @@ static inline unsigned int ebitmap_next_positive(struct ebitmap *e,
 #define EBITMAP_NODE_OFFSET(node, bit)	\
 	(((bit) - (node)->startbit) % EBITMAP_UNIT_SIZE)
 
-static inline int ebitmap_node_get_bit(struct ebitmap_node *n,
+static inline int ebitmap_node_get_bit(const struct ebitmap_node *n,
 				       unsigned int bit)
 {
 	unsigned int index = EBITMAP_NODE_INDEX(n, bit);
@@ -122,15 +122,15 @@ static inline void ebitmap_node_clr_bit(struct ebitmap_node *n,
 	     (bit) < ebitmap_length(e);			\
 	     (bit) = ebitmap_next_positive(e, &(n), bit))	\
 
-int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2);
-int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src);
-int ebitmap_and(struct ebitmap *dst, struct ebitmap *e1, struct ebitmap *e2);
-int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit);
-int ebitmap_get_bit(struct ebitmap *e, unsigned long bit);
+int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2);
+int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src);
+int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1, const struct ebitmap *e2);
+int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2, u32 last_e2bit);
+int ebitmap_get_bit(const struct ebitmap *e, unsigned long bit);
 int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value);
 void ebitmap_destroy(struct ebitmap *e);
 int ebitmap_read(struct ebitmap *e, void *fp);
-int ebitmap_write(struct ebitmap *e, void *fp);
+int ebitmap_write(const struct ebitmap *e, void *fp);
 u32 ebitmap_hash(const struct ebitmap *e, u32 hash);
 
 #ifdef CONFIG_NETLABEL

security/selinux/ss/mls_types.h

@@ -27,13 +27,13 @@ struct mls_range {
 	struct mls_level level[2]; /* low == level[0], high == level[1] */
 };
 
-static inline int mls_level_eq(struct mls_level *l1, struct mls_level *l2)
+static inline int mls_level_eq(const struct mls_level *l1, const struct mls_level *l2)
 {
 	return ((l1->sens == l2->sens) &&
 		ebitmap_cmp(&l1->cat, &l2->cat));
 }
 
-static inline int mls_level_dom(struct mls_level *l1, struct mls_level *l2)
+static inline int mls_level_dom(const struct mls_level *l1, const struct mls_level *l2)
 {
 	return ((l1->sens >= l2->sens) &&
 		ebitmap_contains(&l1->cat, &l2->cat, 0));