KEYS: Split role of the keyring pointer for keyring restrict functions

The first argument to the restrict_link_func_t functions was a keyring
pointer. These functions are called by the key subsystem with this
argument set to the destination keyring, but restrict_link_by_signature
expects a pointer to the relevant trusted keyring.

Restrict functions may need something other than a single struct key
pointer to allow or reject key linkage, so the data used to make that
decision (such as the trust keyring) is moved to a new, fourth
argument. The first argument is now always the destination keyring.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/Documentation/security/keys.txt b/Documentation/security/keys.txt
index 4502237b12a7..bb575ab80207 100644
--- a/Documentation/security/keys.txt
+++ b/Documentation/security/keys.txt
@@ -1054,10 +1054,10 @@ payload contents" for more information.
     can be verified by a key the kernel already has.
 
     When called, the restriction function will be passed the keyring being
-    added to, the key flags value and the type and payload of the key being
-    added.  Note that when a new key is being created, this is called between
-    payload preparsing and actual key creation.  The function should return 0
-    to allow the link or an error to reject it.
+    added to, the key type, the payload of the key being added, and data to be
+    used in the restriction check.  Note that when a new key is being created,
+    this is called between payload preparsing and actual key creation.  The
+    function should return 0 to allow the link or an error to reject it.
 
     A convenience function, restrict_link_reject, exists to always return
     -EPERM to in this case.