perf tests shell: Fix check for libtracevent support

Test “Use vfs_getname probe to get syscall args filenames” fails in
environment with missing libtraceevent support as below:

82: Use vfs_getname probe to get syscall args filenames :
--- start ---
test child forked, pid 304726
Recording open file:
event syntax error: 'probe:vfs_getname*'
\___ unsupported tracepoint

libtraceevent is necessary for tracepoint support
Run 'perf list' for a list of valid events

Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list available events
test child finished with -1
---- end ----
Use vfs_getname probe to get syscall args filenames: FAILED!

The environment has debuginfo but is missing the libtraceevent devel.

Hence perf is compiled without libtraceevent support. The test tries to
add probe “probe:vfs_getname” and then uses it with “perf record”. This
fails at function “parse_events_add_tracepoint" due to missing
libtraceevent.

Similarly "probe libc's inet_pton & backtrace it with ping" test slso
fails with same reason.

Add a function in 'perf test shell' library to check if perf record with
—dry-run reports any error on missing support for libtraceevent. Update
both the tests to use this new function “skip_no_probe_record_support”
before proceeding With using probe point via perf builtin record.

With the change,

82: Use vfs_getname probe to get syscall args filenames :
--- start ---
test child forked, pid 305014
Recording open file:
libtraceevent is necessary for tracepoint support
test child finished with -2
---- end ----
Use vfs_getname probe to get syscall args filenames: Skip

81: probe libc's inet_pton & backtrace it with ping :
--- start ---
test child forked, pid 305036
libtraceevent is necessary for tracepoint support
test child finished with -2
---- end ----
probe libc's inet_pton & backtrace it with ping: Skip

Signed-off-by: Athira Rajeev <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Disha Goel <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Madhavan Srinivasan <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Nageswara R Sastry <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: [e-mail],
Cc: [e-mail]
Link: http://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/shell/lib/probe_vfs_getname.sh

···
 	add_probe_vfs_getname -v 2>&1 | grep -E -q "^(Failed to find the path for the kernel|Debuginfo-analysis is not supported)|(file has no debug information)" && return 2
 	return 1
 }
+
+# check if perf is compiled with libtraceevent support
+skip_no_probe_record_support() {
+	if [ $had_vfs_getname -eq 1 ] ; then
+		perf record --dry-run -e $1 2>&1 | grep "libtraceevent is necessary for tracepoint support" && return 2
+		return 1
+	fi
+}

tools/perf/tests/shell/record+probe_libc_inet_pton.sh

···
 # Arnaldo Carvalho de Melo <[e-mail]>, 2017
 
 . $(dirname $0)/lib/probe.sh
+. $(dirname $0)/lib/probe_vfs_getname.sh
 
 libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1/g')
 nm -Dg $libc 2>/dev/null | fgrep -q inet_pton || exit 254
···
 
 	perf_data=`mktemp -u /tmp/perf.data.XXX`
 	perf_script=`mktemp -u /tmp/perf.script.XXX`
+
+	# Check presence of libtraceevent support to run perf record
+	skip_no_probe_record_support "$event_name/$eventattr/"
+	[ $? -eq 2 ] && return 2
+
 	perf record -e $event_name/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1
 	# check if perf data file got created in above step.
 	if [ ! -e $perf_data ]; then

tools/perf/tests/shell/record+script_probe_vfs_getname.sh

···
 
 record_open_file() {
 	echo "Recording open file:"
+	# Check presence of libtraceevent support to run perf record
+	skip_no_probe_record_support "probe:vfs_getname*"
+	[ $? -eq 2 ] && return 2
 	perf record -o ${perfdata} -e probe:vfs_getname\* touch $file
 }