1clear_trace() { # reset trace output
2    echo > trace
3}
4
5disable_tracing() { # stop trace recording
6    echo 0 > tracing_on
7}
8
9enable_tracing() { # start trace recording
10    echo 1 > tracing_on
11}
12
13reset_tracer() { # reset the current tracer
14    echo nop > current_tracer
15}
16
17reset_trigger_file() {
18    # remove action triggers first
19    grep -H ':on[^:]*(' $@ |
20    while read line; do
21        cmd=`echo $line | cut -f2- -d: | cut -f1 -d"["`
22	file=`echo $line | cut -f1 -d:`
23	echo "!$cmd" >> $file
24    done
25    grep -Hv ^# $@ |
26    while read line; do
27        cmd=`echo $line | cut -f2- -d: | cut -f1 -d"["`
28	file=`echo $line | cut -f1 -d:`
29	echo "!$cmd" > $file
30    done
31}
32
33reset_trigger() { # reset all current setting triggers
34    if [ -d events/synthetic ]; then
35        reset_trigger_file events/synthetic/*/trigger
36    fi
37    reset_trigger_file events/*/*/trigger
38}
39
40reset_events_filter() { # reset all current setting filters
41    grep -v ^none events/*/*/filter |
42    while read line; do
43	echo 0 > `echo $line | cut -f1 -d:`
44    done
45}
46
47reset_ftrace_filter() { # reset all triggers in set_ftrace_filter
48    if [ ! -f set_ftrace_filter ]; then
49      return 0
50    fi
51    echo > set_ftrace_filter
52    grep -v '^#' set_ftrace_filter | while read t; do
53	tr=`echo $t | cut -d: -f2`
54	if [ "$tr" = "" ]; then
55	    continue
56	fi
57	if ! grep -q "$t" set_ftrace_filter; then
58		continue;
59	fi
60	name=`echo $t | cut -d: -f1 | cut -d' ' -f1`
61	if [ $tr = "enable_event" -o $tr = "disable_event" ]; then
62	    tr=`echo $t | cut -d: -f2-4`
63	    limit=`echo $t | cut -d: -f5`
64	else
65	    tr=`echo $t | cut -d: -f2`
66	    limit=`echo $t | cut -d: -f3`
67	fi
68	if [ "$limit" != "unlimited" ]; then
69	    tr="$tr:$limit"
70	fi
71	echo "!$name:$tr" > set_ftrace_filter
72    done
73}
74
75disable_events() {
76    echo 0 > events/enable
77}
78
79clear_synthetic_events() { # reset all current synthetic events
80    grep -v ^# synthetic_events |
81    while read line; do
82        echo "!$line" >> synthetic_events
83    done
84}
85
86initialize_ftrace() { # Reset ftrace to initial-state
87# As the initial state, ftrace will be set to nop tracer,
88# no events, no triggers, no filters, no function filters,
89# no probes, and tracing on.
90    disable_tracing
91    reset_tracer
92    reset_trigger
93    reset_events_filter
94    reset_ftrace_filter
95    disable_events
96    [ -f set_event_pid ] && echo > set_event_pid
97    [ -f set_ftrace_pid ] && echo > set_ftrace_pid
98    [ -f set_ftrace_notrace ] && echo > set_ftrace_notrace
99    [ -f set_graph_function ] && echo | tee set_graph_*
100    [ -f stack_trace_filter ] && echo > stack_trace_filter
101    [ -f kprobe_events ] && echo > kprobe_events
102    [ -f uprobe_events ] && echo > uprobe_events
103    [ -f synthetic_events ] && echo > synthetic_events
104    [ -f snapshot ] && echo 0 > snapshot
105    clear_trace
106    enable_tracing
107}
108
109check_requires() { # Check required files and tracers
110    for i in "$@" ; do
111        r=${i%:README}
112        t=${i%:tracer}
113        if [ $t != $i ]; then
114            if ! grep -wq $t available_tracers ; then
115                echo "Required tracer $t is not configured."
116                exit_unsupported
117            fi
118        elif [ $r != $i ]; then
119            if ! grep -Fq "$r" README ; then
120                echo "Required feature pattern \"$r\" is not in README."
121                exit_unsupported
122            fi
123        elif [ ! -e $i ]; then
124            echo "Required feature interface $i doesn't exist."
125            exit_unsupported
126        fi
127    done
128}
129
130LOCALHOST=127.0.0.1
131
132yield() {
133    ping $LOCALHOST -c 1 || sleep .001 || usleep 1 || sleep 1
134}
135
136# Since probe event command may include backslash, explicitly use printf "%s"
137# to NOT interpret it.
138ftrace_errlog_check() { # err-prefix command-with-error-pos-by-^ command-file
139    pos=$(printf "%s" "${2%^*}" | wc -c) # error position
140    command=$(printf "%s" "$2" | tr -d ^)
141    echo "Test command: $command"
142    echo > error_log
143    (! printf "%s" "$command" >> "$3" ) 2> /dev/null
144    grep "$1: error:" -A 3 error_log
145    N=$(tail -n 1 error_log | wc -c)
146    # "  Command: " and "^\n" => 13
147    test $(expr 13 + $pos) -eq $N
148}
149