sgi-xp: Use designated initializers

Prepare to mark sensitive kernel structures for randomization by making
sure they're using designated initializers. In this case, no initializers
are needed (they can be NULL initialized and callers adjusted to check
for NULL, which is more efficient than an indirect call).

Cc: Robin Holt <robinmholt@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Hellwig <hch@infradead.org>

1 files changed, 7 insertions, 29 deletions

diff --git a/drivers/misc/sgi-xp/xp_main.c b/drivers/misc/sgi-xp/xp_main.c
index 01be66d02ca8..6d7f557fd1c1 100644
--- a/drivers/misc/sgi-xp/xp_main.c
+++ b/drivers/misc/sgi-xp/xp_main.c
@@ -69,23 +69,9 @@ struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS];
 EXPORT_SYMBOL_GPL(xpc_registrations);
 
 /*
- * Initialize the XPC interface to indicate that XPC isn't loaded.
+ * Initialize the XPC interface to NULL to indicate that XPC isn't loaded.
  */
-static enum xp_retval
-xpc_notloaded(void)
-{
-	return xpNotLoaded;
-}
-
-struct xpc_interface xpc_interface = {
-	(void (*)(int))xpc_notloaded,
-	(void (*)(int))xpc_notloaded,
-	(enum xp_retval(*)(short, int, u32, void *, u16))xpc_notloaded,
-	(enum xp_retval(*)(short, int, u32, void *, u16, xpc_notify_func,
-			   void *))xpc_notloaded,
-	(void (*)(short, int, void *))xpc_notloaded,
-	(enum xp_retval(*)(short, void *))xpc_notloaded
-};
+struct xpc_interface xpc_interface = { };
 EXPORT_SYMBOL_GPL(xpc_interface);
 
 /*
@@ -115,17 +101,7 @@ EXPORT_SYMBOL_GPL(xpc_set_interface);
 void
 xpc_clear_interface(void)
 {
-	xpc_interface.connect = (void (*)(int))xpc_notloaded;
-	xpc_interface.disconnect = (void (*)(int))xpc_notloaded;
-	xpc_interface.send = (enum xp_retval(*)(short, int, u32, void *, u16))
-	    xpc_notloaded;
-	xpc_interface.send_notify = (enum xp_retval(*)(short, int, u32, void *,
-						       u16, xpc_notify_func,
-						       void *))xpc_notloaded;
-	xpc_interface.received = (void (*)(short, int, void *))
-	    xpc_notloaded;
-	xpc_interface.partid_to_nasids = (enum xp_retval(*)(short, void *))
-	    xpc_notloaded;
+	memset(&xpc_interface, 0, sizeof(xpc_interface));
 }
 EXPORT_SYMBOL_GPL(xpc_clear_interface);
 
@@ -188,7 +164,8 @@ xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
 
 	mutex_unlock(&registration->mutex);
 
-	xpc_interface.connect(ch_number);
+	if (xpc_interface.connect)
+		xpc_interface.connect(ch_number);
 
 	return xpSuccess;
 }
@@ -237,7 +214,8 @@ xpc_disconnect(int ch_number)
 	registration->assigned_limit = 0;
 	registration->idle_limit = 0;
 
-	xpc_interface.disconnect(ch_number);
+	if (xpc_interface.disconnect)
+		xpc_interface.disconnect(ch_number);
 
 	mutex_unlock(&registration->mutex);