tested against 5.8 ftrace tests: NO crashing now, fixed.

cking@riscv64:~/linux/tools/testing/selftests/ftrace$ sudo ./ftracetest 
=== Ftrace unit tests ===
[1] Basic trace file check	[PASS]
[2] Basic test for tracers	[PASS]
[3] Basic trace clock test	[PASS]
[4] Basic event tracing check	[PASS]
[5] Change the ringbuffer size	[PASS]
[6] Snapshot and tracing setting	[PASS]
[7] trace_pipe and trace_marker	[PASS]
[8] Test ftrace direct functions against tracers	[UNRESOLVED]
[9] Test ftrace direct functions against kprobes	[UNSUPPORTED]
[10] Generic dynamic event - add/remove kprobe events	[FAIL]
[11] Generic dynamic event - add/remove synthetic events	[UNSUPPORTED]
[12] Generic dynamic event - selective clear (compatibility)	[UNSUPPORTED]
[13] Generic dynamic event - generic clear event	[UNSUPPORTED]
[14] event tracing - enable/disable with event level files	[PASS]
[15] event tracing - restricts events based on pid notrace filtering	[PASS]
[16] event tracing - restricts events based on pid	[PASS]
[17] event tracing - enable/disable with subsystem level files	[PASS]
[18] event tracing - enable/disable with top level files	[PASS]
[19] Test trace_printk from module	[UNRESOLVED]
[20] ftrace - function graph filters with stack tracer	[PASS]
[21] ftrace - function graph filters	[PASS]
[22] ftrace - function glob filters	[PASS]
[23] ftrace - function pid notrace filters	[PASS]
[24] ftrace - function pid filters	[PASS]
[25] ftrace - stacktrace filter command	[PASS]
[26] ftrace - function trace with cpumask	[PASS]
[27] ftrace - test for function event triggers	[PASS]
[28] ftrace - function trace on module	[UNRESOLVED]
[29] ftrace - function profiling	[PASS]
[30] ftrace - function profiler with function tracing	[PASS]
[31] ftrace - test reading of set_ftrace_filter	[PASS]
[32] ftrace - Max stack tracer	[PASS]
[33] ftrace - test for function traceon/off triggers	[PASS]
[34] ftrace - test tracing error log support	[PASS]
[35] Test creation and deletion of trace instances while setting an event	[PASS]
[36] Test creation and deletion of trace instances	[PASS]
[37] Kprobe dynamic event - adding and removing	[UNSUPPORTED]
[38] Kprobe dynamic event - busy event check	[UNSUPPORTED]
[39] Kprobe dynamic event with arguments	[UNSUPPORTED]
[40] Kprobe event with comm arguments	[UNSUPPORTED]
[41] Kprobe event string type argument	[UNSUPPORTED]
[42] Kprobe event symbol argument	[UNSUPPORTED]
[43] Kprobe event argument syntax	[UNSUPPORTED]
[44] Kprobes event arguments with types	[UNSUPPORTED]
[45] Kprobe event user-memory access	[UNSUPPORTED]
[46] Kprobe event auto/manual naming	[UNSUPPORTED]
[47] Kprobe dynamic event with function tracer	[UNSUPPORTED]
[48] Kprobe dynamic event - probing module	[UNSUPPORTED]
[49] Create/delete multiprobe on kprobe event	[UNSUPPORTED]
[50] Kprobe event parser error log check	[UNSUPPORTED]
[51] Kretprobe dynamic event with arguments	[UNSUPPORTED]
[52] Kretprobe dynamic event with maxactive	[UNSUPPORTED]
[53] Register/unregister many kprobe events	[UNSUPPORTED]
[54] Kprobe events - probe points	[UNSUPPORTED]
[55] Kprobe dynamic event - adding and removing	[UNSUPPORTED]
[56] Uprobe event parser error log check	[UNSUPPORTED]
[57] test for the preemptirqsoff tracer	[UNSUPPORTED]
[58] Meta-selftest: Checkbashisms	[UNRESOLVED]
[59] Test wakeup tracer	[PASS]
[60] Test wakeup RT tracer	[PASS]
[61] event trigger - test inter-event histogram trigger expected fail actions	[UNSUPPORTED]
[62] event trigger - test field variable support	[UNSUPPORTED]
[63] event trigger - test inter-event combined histogram trigger	[UNSUPPORTED]
[64] event trigger - test multiple actions on hist trigger	[UNSUPPORTED]
[65] event trigger - test inter-event histogram trigger onchange action	[UNSUPPORTED]
[66] event trigger - test inter-event histogram trigger onmatch action	[UNSUPPORTED]
[67] event trigger - test inter-event histogram trigger onmatch-onmax action	[UNSUPPORTED]
[68] event trigger - test inter-event histogram trigger onmax action	[UNSUPPORTED]
[69] event trigger - test inter-event histogram trigger snapshot action	[UNSUPPORTED]
[70] event trigger - test synthetic event create remove	[PASS]
[71] event trigger - test synthetic_events syntax parser	[PASS]
[72] event trigger - test inter-event histogram trigger trace action	[UNSUPPORTED]
[73] event trigger - test event enable/disable trigger	[PASS]
[74] event trigger - test trigger filter	[PASS]
[75] event trigger - test histogram modifiers	[UNSUPPORTED]
[76] event trigger - test histogram parser errors	[UNSUPPORTED]
[77] event trigger - test histogram trigger	[UNSUPPORTED]
[78] event trigger - test multiple histogram triggers	[UNSUPPORTED]
[79] event trigger - test snapshot-trigger	[PASS]
[80] event trigger - test stacktrace-trigger	[PASS]
[81] trace_marker trigger - test histogram trigger	[UNSUPPORTED]
[82] trace_marker trigger - test snapshot trigger	[PASS]
[83] trace_marker trigger - test histogram with synthetic event against kernel event	[UNSUPPORTED]
[84] trace_marker trigger - test histogram with synthetic event	[UNSUPPORTED]
[85] event trigger - test traceon/off trigger	[PASS]
[86] (instance)  Basic test for tracers	[PASS]
[87] (instance)  Basic trace clock test	[PASS]
[88] (instance)  Change the ringbuffer size	[PASS]
[89] (instance)  Snapshot and tracing setting	[PASS]
[90] (instance)  trace_pipe and trace_marker	[PASS]
[91] (instance)  event tracing - enable/disable with event level files	[PASS]
[92] (instance)  event tracing - restricts events based on pid notrace filtering	[PASS]
[93] (instance)  event tracing - restricts events based on pid	[PASS]
[94] (instance)  event tracing - enable/disable with subsystem level files	[PASS]
[95] (instance)  ftrace - function pid notrace filters	[PASS]
[96] (instance)  ftrace - function pid filters	[PASS]
[97] (instance)  ftrace - stacktrace filter command	[PASS]
[98] (instance)  ftrace - test for function event triggers	[FAIL]
[99] (instance)  ftrace - test for function traceon/off triggers	[PASS]
[100] (instance)  event trigger - test event enable/disable trigger	[PASS]
[101] (instance)  event trigger - test trigger filter	[PASS]
[102] (instance)  event trigger - test histogram modifiers	[UNSUPPORTED]
[103] (instance)  event trigger - test histogram trigger	[UNSUPPORTED]
[104] (instance)  event trigger - test multiple histogram triggers	[UNSUPPORTED]
[105] (instance)  trace_marker trigger - test histogram trigger	[UNSUPPORTED]
[106] (instance)  trace_marker trigger - test snapshot trigger	[PASS]


# of passed:  54
# of failed:  2
# of unresolved:  4
# of untested:  0
# of unsupported:  46
# of xfailed:  0
# of undefined(test bug):  0