perf auxtrace: Make auxtrace_queues__add_buffer() return buffer_ptr

In preparation for supporting AUX area sampling buffers,
auxtrace_queues__add_buffer() needs to be more generic. To that end, make
it return buffer_ptr instead of the caller.

Signed-off-by: Adrian Hunter <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/auxtrace.c

···
 static int auxtrace_queues__add_buffer(struct auxtrace_queues *queues,
 				       struct perf_session *session,
 				       unsigned int idx,
-				       struct auxtrace_buffer *buffer)
+				       struct auxtrace_buffer *buffer,
+				       struct auxtrace_buffer **buffer_ptr)
 {
+	int err;
+
 	if (session->one_mmap) {
 		buffer->data = buffer->data_offset - session->one_mmap_offset +
 			       session->one_mmap_addr;
···
 		buffer->data_needs_freeing = true;
 	} else if (BITS_PER_LONG == 32 &&
 		   buffer->size > BUFFER_LIMIT_FOR_32_BIT) {
-		int err;
-
 		err = auxtrace_queues__split_buffer(queues, idx, buffer);
 		if (err)
 			return err;
 	}
 
-	return auxtrace_queues__queue_buffer(queues, idx, buffer);
+	err = auxtrace_queues__queue_buffer(queues, idx, buffer);
+	if (err)
+		return err;
+
+	/* FIXME: Doesn't work for split buffer */
+	if (buffer_ptr)
+		*buffer_ptr = buffer;
+
+	return 0;
 }
 
 static bool filter_cpu(struct perf_session *session, int cpu)
···
 	buffer->size = event->auxtrace.size;
 	idx = event->auxtrace.idx;
 
-	err = auxtrace_queues__add_buffer(queues, session, idx, buffer);
+	err = auxtrace_queues__add_buffer(queues, session, idx, buffer,
+					  buffer_ptr);
 	if (err)
 		goto out_err;
-
-	if (buffer_ptr)
-		*buffer_ptr = buffer;
 
 	return 0;