staging: hv: check return value of RingBufferInit()

RingBufferInit() would always return sucess and instead relied on an
ASSERT() to test for an error condition.  Remove the ASSERT() and
return -EINVAL instead.  The return value of RingBufferInit() was also
never checked, so check it.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/Channel.c

@@ -203,9 +203,18 @@ int VmbusChannelOpen(struct vmbus_channel *NewChannel, u32 SendRingBufferSize,
 	NewChannel->RingBufferPageCount = (SendRingBufferSize +
 					   RecvRingBufferSize) >> PAGE_SHIFT;
 
-	RingBufferInit(&NewChannel->Outbound, out, SendRingBufferSize);
+	ret = RingBufferInit(&NewChannel->Outbound, out, SendRingBufferSize);
+	if (!ret) {
+		err = ret;
+		goto errorout;
+	}
+
+	ret = RingBufferInit(&NewChannel->Inbound, in, RecvRingBufferSize);
+	if (!ret) {
+		err = ret;
+		goto errorout;
+	}
 
-	RingBufferInit(&NewChannel->Inbound, in, RecvRingBufferSize);
 
 	/* Establish the gpadl for the ring buffer */
 	DPRINT_DBG(VMBUS, "Establishing ring buffer's gpadl for channel %p...",

drivers/staging/hv/RingBuffer.c

@@ -301,7 +301,8 @@ u32 GetRingBufferInterruptMask(RING_BUFFER_INFO *rbi)
 --*/
 int RingBufferInit(RING_BUFFER_INFO *RingInfo, void *Buffer, u32 BufferLen)
 {
-	ASSERT(sizeof(RING_BUFFER) == PAGE_SIZE);
+	if (sizeof(RING_BUFFER) != PAGE_SIZE)
+		return -EINVAL;
 
 	memset(RingInfo, 0, sizeof(RING_BUFFER_INFO));