Hi Shaobo, On Monday 20 Feb 2017 12:49:18 Shaobo wrote: > Hi Laurent, > > I'd like to. It sounds interesting and useful to me. Could you give me some > pointers about how to audit drivers? It's pretty simple, you need to check all functions that call get_queue_ctx() and follow the call stacks up to drivers to see if the context can be NULL. It's a bit of work though :-) -- Regards, Laurent Pinchart