keys: allow clients to set key perms in key_create_or_update()

The key_create_or_update() function provided by the keyring code has a default
set of permissions that are always applied to the key when created.  This
might not be desirable to all clients.

Here's a patch that adds a "perm" parameter to the function to address this,
which can be set to KEY_PERM_UNDEF to revert to the current behaviour.

Signed-off-by: Arun Raghavan <arunsr@cse.iitk.ac.in>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/key.h b/include/linux/key.h
index 163f864..8b0bd33 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -67,6 +67,8 @@
 #define KEY_OTH_SETATTR	0x00000020
 #define KEY_OTH_ALL	0x0000003f
 
+#define KEY_PERM_UNDEF	0xffffffff
+
 struct seq_file;
 struct user_struct;
 struct signal_struct;
@@ -232,6 +234,7 @@
 				      const char *description,
 				      const void *payload,
 				      size_t plen,
+				      key_perm_t perm,
 				      unsigned long flags);
 
 extern int key_update(key_ref_t key,