[PATCH V7 1/3] tracing: add a possibility of exporting function trace to other places instead of ring buffer only

On Tue, 15 Nov 2016 16:14:29 +0800
Chunyan Zhang [off-list ref] wrote:

quoted

Then why have a

        if (export->write)


Is there every going to be a case where export will not have a write
function?  

There shouldn't be.

I can move this if statement to the register_ftrace_export() to ensure
users won't wrongly use it, that's saying the write() of trace_export
has been set before being registered to 'ftrace_exports_list'.

Looks like it's already there:

+int register_ftrace_export(struct trace_export *export)
+{
+	if (WARN_ON_ONCE(!export->write))
+		return -1;


-- Steve