selftests/ftrace: check for do_sys_openat2 in user-memory test

More recent libc implementations are now using openat/openat2 system
calls so also add do_sys_openat2 to the tracing so that the test
passes on these systems because do_sys_open may not be called.

Thanks to Masami Hiramatsu for the help on getting this fix to work
correctly.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/ftrace: Support ":README" suffix for requires

Add ":README" suffix support for the requires list, so that
the testcase can list up the required string for README file
to the requires list.

Note that the required string is treated as a fixed string,
instead of regular expression. Also, the testcase can specify
a string containing spaces with quotes. E.g.

# requires: "place: [<module>:]<symbol>":README

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: 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>

selftests/ftrace: Add user-memory access syntax testcase

Add a user-memory access syntax testcase which checks
new user-memory access syntax and ustring type.

Link: http://lkml.kernel.org/r/155789873385.26965.9557271156179140676.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>