perf auxtrace: Make auxtrace_queues__add_buffer() allocate struct buffer

In preparation for supporting AUX area sampling buffers,
auxtrace_queues__add_buffer() needs to be more generic. To that end,
move memory allocation for struct buffer into it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1520327598-1317-7-git-send-email-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/auxtrace.c

@@ -308,7 +308,11 @@ static int auxtrace_queues__add_buffer(struct auxtrace_queues *queues,
 				       struct auxtrace_buffer *buffer,
 				       struct auxtrace_buffer **buffer_ptr)
 {
-	int err;
+	int err = -ENOMEM;
+
+	buffer = memdup(buffer, sizeof(*buffer));
+	if (!buffer)
+		return -ENOMEM;
 
 	if (session->one_mmap) {
 		buffer->data = buffer->data_offset - session->one_mmap_offset +
@@ -316,24 +320,28 @@ static int auxtrace_queues__add_buffer(struct auxtrace_queues *queues,
 	} else if (perf_data__is_pipe(session->data)) {
 		buffer->data = auxtrace_copy_data(buffer->size, session);
 		if (!buffer->data)
-			return -ENOMEM;
+			goto out_free;
 		buffer->data_needs_freeing = true;
 	} else if (BITS_PER_LONG == 32 &&
 		   buffer->size > BUFFER_LIMIT_FOR_32_BIT) {
 		err = auxtrace_queues__split_buffer(queues, idx, buffer);
 		if (err)
-			return err;
+			goto out_free;
 	}
 
 	err = auxtrace_queues__queue_buffer(queues, idx, buffer);
 	if (err)
-		return err;
+		goto out_free;
 
 	/* FIXME: Doesn't work for split buffer */
 	if (buffer_ptr)
 		*buffer_ptr = buffer;
 
 	return 0;
+
+out_free:
+	auxtrace_buffer__free(buffer);
+	return err;
 }
 
 static bool filter_cpu(struct perf_session *session, int cpu)
@@ -348,36 +356,22 @@ int auxtrace_queues__add_event(struct auxtrace_queues *queues,
 			       union perf_event *event, off_t data_offset,
 			       struct auxtrace_buffer **buffer_ptr)
 {
-	struct auxtrace_buffer *buffer;
-	unsigned int idx;
-	int err;
+	struct auxtrace_buffer buffer = {
+		.pid = -1,
+		.tid = event->auxtrace.tid,
+		.cpu = event->auxtrace.cpu,
+		.data_offset = data_offset,
+		.offset = event->auxtrace.offset,
+		.reference = event->auxtrace.reference,
+		.size = event->auxtrace.size,
+	};
+	unsigned int idx = event->auxtrace.idx;
 
 	if (filter_cpu(session, event->auxtrace.cpu))
 		return 0;
 
-	buffer = zalloc(sizeof(struct auxtrace_buffer));
-	if (!buffer)
-		return -ENOMEM;
-
-	buffer->pid = -1;
-	buffer->tid = event->auxtrace.tid;
-	buffer->cpu = event->auxtrace.cpu;
-	buffer->data_offset = data_offset;
-	buffer->offset = event->auxtrace.offset;
-	buffer->reference = event->auxtrace.reference;
-	buffer->size = event->auxtrace.size;
-	idx = event->auxtrace.idx;
-
-	err = auxtrace_queues__add_buffer(queues, session, idx, buffer,
+	return auxtrace_queues__add_buffer(queues, session, idx, &buffer,
 					   buffer_ptr);
-	if (err)
-		goto out_err;
-
-	return 0;
-
-out_err:
-	auxtrace_buffer__free(buffer);
-	return err;
 }
 
 static int auxtrace_queues__add_indexed_event(struct auxtrace_queues *queues,