lsm: move the key hook comments to security/security.c

This patch relocates the LSM hook function comments to the function
definitions, in keeping with the current kernel conventions.  This
should make the hook descriptions more easily discoverable and easier
to maintain.

While formatting changes have been done to better fit the kernel-doc
style, content changes have been kept to a minimum and limited to
text which was obviously incorrect and/or outdated.  It is expected
the future patches will improve the quality of the function header
comments.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Author: pcmoore

include/linux/lsm_hooks.h

@@ -32,38 +32,6 @@
 /**
  * union security_list_options - Linux Security Module hook function list
  *
- * Security hooks affecting all Key Management operations
- *
- * @key_alloc:
- *	Permit allocation of a key and assign security data. Note that key does
- *	not have a serial number assigned at this point.
- *	@key points to the key.
- *	@flags is the allocation flags.
- *	Return 0 if permission is granted, -ve error otherwise.
- * @key_free:
- *	Notification of destruction; free security data.
- *	@key points to the key.
- *	No return value.
- * @key_permission:
- *	See whether a specific operational right is granted to a process on a
- *	key.
- *	@key_ref refers to the key (key pointer + possession attribute bit).
- *	@cred points to the credentials to provide the context against which to
- *	evaluate the security data on the key.
- *	@perm describes the combination of permissions required of this key.
- *	Return 0 if permission is granted, -ve error otherwise.
- * @key_getsecurity:
- *	Get a textual representation of the security context attached to a key
- *	for the purposes of honouring KEYCTL_GETSECURITY.  This function
- *	allocates the storage for the NUL-terminated string and the caller
- *	should free it.
- *	@key points to the key to be queried.
- *	@_buffer points to a pointer that should be set to point to the
- *	resulting string (if no label or an error occurs).
- *	Return the length of the string (including terminating NUL) or -ve if
- *	an error.
- *	May also return 0 (and a NULL buffer pointer) if there is no label.
- *
  * Security hooks affecting all System V IPC operations.
  *
  * @ipc_permission:

security/security.c

@@ -4468,23 +4468,63 @@ EXPORT_SYMBOL(security_skb_classify_flow);
 
 #ifdef CONFIG_KEYS
 
+/**
+ * security_key_alloc() - Allocate and initialize a kernel key LSM blob
+ * @key: key
+ * @cred: credentials
+ * @flags: allocation flags
+ *
+ * Permit allocation of a key and assign security data. Note that key does not
+ * have a serial number assigned at this point.
+ *
+ * Return: Return 0 if permission is granted, -ve error otherwise.
+ */
 int security_key_alloc(struct key *key, const struct cred *cred,
 		       unsigned long flags)
 {
 	return call_int_hook(key_alloc, 0, key, cred, flags);
 }
 
+/**
+ * security_key_free() - Free a kernel key LSM blob
+ * @key: key
+ *
+ * Notification of destruction; free security data.
+ */
 void security_key_free(struct key *key)
 {
 	call_void_hook(key_free, key);
 }
 
+/**
+ * security_key_permission() - Check if a kernel key operation is allowed
+ * @key_ref: key reference
+ * @cred: credentials of actor requesting access
+ * @need_perm: requested permissions
+ *
+ * See whether a specific operational right is granted to a process on a key.
+ *
+ * Return: Return 0 if permission is granted, -ve error otherwise.
+ */
 int security_key_permission(key_ref_t key_ref, const struct cred *cred,
 			    enum key_need_perm need_perm)
 {
 	return call_int_hook(key_permission, 0, key_ref, cred, need_perm);
 }
 
+/**
+ * security_key_getsecurity() - Get the key's security label
+ * @key: key
+ * @buffer: security label buffer
+ *
+ * Get a textual representation of the security context attached to a key for
+ * the purposes of honouring KEYCTL_GETSECURITY.  This function allocates the
+ * storage for the NUL-terminated string and the caller should free it.
+ *
+ * Return: Returns the length of @buffer (including terminating NUL) or -ve if
+ *         an error occurs.  May also return 0 (and a NULL buffer pointer) if
+ *         there is no security label assigned to the key.
+ */
 int security_key_getsecurity(struct key *key, char **_buffer)
 {
 	*_buffer = NULL;