selftests/ftrace: Convert required interface checks into requires list

Convert the required tracefs interface checking code with
requires: list.

Fixed merge conflicts in trigger-hist.tc and trigger-trace-marker-hist.tc
Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/ftrace: Return unsupported for the unconfigured features

As same as other test cases, return unsupported if kprobe_events
or argument access feature are not found.

There can be a new arch which does not port those features yet,
and an older kernel which doesn't support it.
Those can not enable the features.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"

There is a spelling mistake in a trace_printk message. As well as in
the selftests that search for this string.

Link: http://lkml.kernel.org/r/20191115085938.38947-1-colin.king@canonical.com
Link: http://lkml.kernel.org/r/20191115090356.39572-1-colin.king@canonical.com

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ftrace/selftests: Update the direct call selftests to test two direct calls

The register_ftrace_direct() takes a different path if there's already a
direct call registered, but this was not tested in the self tests. Now that
there's a second direct caller test module, we can use this to test not only
one direct caller, but two.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ftrace/selftest: Add tests to test register_ftrace_direct()

Add two test cases that test the new ftrace direct functionality if the
ftrace-direct sample module is available. One test case tests against each
available tracer (function, function_graph, mmiotrace, etc), and the other
test tests against a kprobe at the same location as the direct caller. Both
tests follow the same pattern of testing combinations:

enable test (either the tracer or the kprobe)
load direct function module
unload direct function module
disable test

enable test
load direct function module
disable test
unload direct function module

load direct function module
enable test
disable test
unload direct function module

load direct function module
enable test
unload direct function module
disable test

As most the bugs in development happened with various ways of enabling or
disabling the direct calls with function tracer in one of these
combinations.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>