Merge tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "One new feature was added to ftrace, which is the trace_marker now
  supports triggers. For example:

    # cd /sys/kernel/debug/tracing
    # echo 'snapshot' > events/ftrace/print/trigger
    # echo 'cause snapshot' > trace_marker

  The rest of the changes are various clean ups and also one stable fix
  that was added late in the cycle"

* tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (21 commits)
  tracing: Use match_string() instead of open coding it in trace_set_options()
  branch-check: fix long->int truncation when profiling branches
  ring-buffer: Fix typo in comment
  ring-buffer: Fix a bunch of typos in comments
  tracing/selftest: Add test to test simple snapshot trigger for trace_marker
  tracing/selftest: Add test to test hist trigger between kernel event and trace_marker
  tracing/selftest: Add selftests to test trace_marker histogram triggers
  ftrace/selftest: Fix reset_trigger() to handle triggers with filters
  ftrace/selftest: Have the reset_trigger code be a bit more careful
  tracing: Document trace_marker triggers
  tracing: Allow histogram triggers to access ftrace internal events
  tracing: Prevent further users of zero size static arrays in trace events
  tracing: Have zero size length in filter logic be full string
  tracing: Add trigger file for trace_markers tracefs/ftrace/print
  tracing: Do not show filter file for ftrace internal events
  tracing: Add brackets in ftrace event dynamic arrays
  tracing: Have event_trace_init() called by trace_init_tracefs()
  tracing: Add __find_event_file() to find event files without restrictions
  tracing: Do not reference event data in post call triggers
  tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}
  ...

include/trace/trace_events.h

@@ -422,6 +422,7 @@ static struct trace_event_functions trace_event_type_funcs_##call = {	\
 	do {								\
 		char *type_str = #type"["__stringify(len)"]";		\
 		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\
+		BUILD_BUG_ON(len <= 0);					\
 		ret = trace_define_field(event_call, type_str, #item,	\
 				 offsetof(typeof(field), item),		\
 				 sizeof(field.item),			\