integrity: Small code improvements

These changes are too small to warrant their own patches:

The keyid and sig_size members of struct signature_v2_hdr are in BE format,
so use a type that makes this assumption explicit. Also, use beXX_to_cpu
instead of __beXX_to_cpu to read them.

Change integrity_kernel_read to take a void * buffer instead of char *
buffer, so that callers don't have to use a cast if they provide a buffer
that isn't a char *.

Add missing #endif comment in ima.h pointing out which macro it refers to.

Add missing fall through comment in ima_appraise.c.

Constify mask_tokens and func_tokens arrays.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

security/integrity/digsig_asymmetric.c

@@ -92,13 +92,13 @@ int asymmetric_verify(struct key *keyring, const char *sig,
 
 	siglen -= sizeof(*hdr);
 
-	if (siglen != __be16_to_cpu(hdr->sig_size))
+	if (siglen != be16_to_cpu(hdr->sig_size))
 		return -EBADMSG;
 
 	if (hdr->hash_algo >= HASH_ALGO__LAST)
 		return -ENOPKG;
 
-	key = request_asymmetric_key(keyring, __be32_to_cpu(hdr->keyid));
+	key = request_asymmetric_key(keyring, be32_to_cpu(hdr->keyid));
 	if (IS_ERR(key))
 		return PTR_ERR(key);
 

security/integrity/iint.c

@@ -182,7 +182,7 @@ security_initcall(integrity_iintcache_init);
  *
  */
 int integrity_kernel_read(struct file *file, loff_t offset,
-			  char *addr, unsigned long count)
+			  void *addr, unsigned long count)
 {
 	mm_segment_t old_fs;
 	char __user *buf = (char __user *)addr;

security/integrity/ima/ima.h

@@ -284,7 +284,7 @@ static inline int ima_read_xattr(struct dentry *dentry,
 	return 0;
 }
 
-#endif
+#endif /* CONFIG_IMA_APPRAISE */
 
 /* LSM based policy rules require audit */
 #ifdef CONFIG_IMA_LSM_RULES

security/integrity/ima/ima_appraise.c

@@ -240,6 +240,7 @@ int ima_appraise_measurement(enum ima_hooks func,
 	case IMA_XATTR_DIGEST_NG:
 		/* first byte contains algorithm id */
 		hash_start = 1;
+		/* fall through */
 	case IMA_XATTR_DIGEST:
 		if (iint->flags & IMA_DIGSIG_REQUIRED) {
 			cause = "IMA-signature-required";

security/integrity/ima/ima_policy.c

@@ -965,7 +965,7 @@ enum {
 	mask_exec = 0, mask_write, mask_read, mask_append
 };
 
-static char *mask_tokens[] = {
+static const char *const mask_tokens[] = {
 	"MAY_EXEC",
 	"MAY_WRITE",
 	"MAY_READ",
@@ -979,7 +979,7 @@ enum {
 	func_policy
 };
 
-static char *func_tokens[] = {
+static const char *const func_tokens[] = {
 	"FILE_CHECK",
 	"MMAP_CHECK",
 	"BPRM_CHECK",

security/integrity/integrity.h

@@ -92,8 +92,8 @@ struct signature_v2_hdr {
 	uint8_t type;		/* xattr type */
 	uint8_t version;	/* signature format version */
 	uint8_t	hash_algo;	/* Digest algorithm [enum hash_algo] */
-	uint32_t keyid;		/* IMA key identifier - not X509/PGP specific */
-	uint16_t sig_size;	/* signature size */
+	__be32 keyid;		/* IMA key identifier - not X509/PGP specific */
+	__be16 sig_size;	/* signature size */
 	uint8_t sig[0];		/* signature payload */
 } __packed;
 
@@ -118,7 +118,8 @@ struct integrity_iint_cache {
 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 
 int integrity_kernel_read(struct file *file, loff_t offset,
-			  char *addr, unsigned long count);
+			  void *addr, unsigned long count);
+
 int __init integrity_read_file(const char *path, char **data);
 
 #define INTEGRITY_KEYRING_EVM		0