selftests/ftrace: Fix probepoint testcase to ignore __pfx_* symbols

Fix kprobe probepoint testcase to ignore __pfx_* prefix symbols. Those are
introduced by commit b341b20d648b ("x86: Add prefix symbols for function
padding") for identifying PADDING_BYTES of NOPs. Since kprobe events can
not probe these prefix symbols, this testcase has to skip those symbols.

Link: https://lore.kernel.org/all/167309835609.640500.9664678940260305746.stgit@devnote3/

Fixes: b341b20d648b ("x86: Add prefix symbols for function padding")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-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: Remove unneeded per-test init/cleanup ftrace

Since ftracetest framework calls initialize_ftrace() right before
each test and after all tests, we don't need to init/cleanup
ftrace for each test case.
Just remove such unneeded init/cleanup code because it can
increase logfile size.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

selftests/ftrace: Fix kprobe string testcase to not probe notrace function

Fix kprobe string argument testcase to not probe notrace
function. Instead, it probes tracefs function which must
be available with ftrace.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

selftests/ftrace: Fix kprobe string testcase to not probe notrace function

Fix kprobe string argument testcase to not probe notrace
function. Instead, it probes tracefs function which must
be available with ftrace.

Link: http://lkml.kernel.org/r/153294607107.32740.1664854684396589624.stgit@devbox

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

selftests: ftrace: Add a testcase for probepoint

Add a testcase for probe point definition. This tests
symbol, address and symbol+offset syntax. The offset
must be positive and smaller than UINT_MAX.

Link: http://lkml.kernel.org/r/152129043097.31874.14273580606301767394.stgit@devbox

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