Pull tracing fixes from Steven Rostedt:
 "Various fixes to the tracing infrastructure:

   - Fix double free when the reg() call fails in
     event_trigger_callback()

   - Fix anomoly of snapshot causing tracing_on flag to change

   - Add selftest to test snapshot and tracing_on affecting each other

   - Fix setting of tracepoint flag on error that prevents probes from
     being deleted.

   - Fix another possible double free that is similar to
     event_trigger_callback()

   - Quiet a gcc warning of a false positive unused variable

   - Fix crash of partial exposed task->comm to trace events"

* tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kthread, tracing: Don't expose half-written comm when creating kthreads
  tracing: Quiet gcc warning about maybe unused link variable
  tracing: Fix possible double free in event_enable_trigger_func()
  tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure
  selftests/ftrace: Add snapshot and tracing_on test case
  ring_buffer: tracing: Inherit the tracing setting to next ring buffer
  tracing: Fix double free of event_trigger_data