uprobe support mix of ftrace and perf

[Masami Hiramatsu]

Hello Oleg,

I have a question about the (revert) commit 48212542067a 
("tracing/uprobes: Revert "Support mix of ftrace and perf""). I found
this limitation still exists on uprobe events. 

Would you have any plan or idea to fix this issue? I thought this revert
patch was a tentative one, and should be fixed afterwards.

Since kprobe events already supported the mix of ftrace and perf, user may
confuse why they can not use the uprobe event if it is used by ftrace.
(perf probe treats both events transparently, and ftrace event interface too.)

Thank you,

-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>