perf test shell: Make perf's inet_pton test more portable

Debian based systems such as Ubuntu have dash as their default shell.
Even if the normal or root user's shell is bash, certain scripts still
call /bin/sh, which points to dash, so we fix this perf test by
rewriting it in a more portable way.

BEFORE:

 $ sudo perf test -v 64
 64: probe libc's inet_pton & backtrace it with ping       :
 --- start ---
 test child forked, pid 31942
 ./tests/shell/record+probe_libc_inet_pton.sh: 18: ./tests/shell/record+probe_libc_inet_pton.sh: expected[0]=ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\): not found
 ./tests/shell/record+probe_libc_inet_pton.sh: 19: ./tests/shell/record+probe_libc_inet_pton.sh: expected[1]=.*inet_pton\+0x[[:xdigit:]]+[[:space:]]\(/lib/x86_64-linux-gnu/libc-2.27.so|inlined\)$: not found
 ./tests/shell/record+probe_libc_inet_pton.sh: 29: ./tests/shell/record+probe_libc_inet_pton.sh: expected[2]=getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\(/lib/x86_64-linux-gnu/libc-2.27.so\)$: not found
 ./tests/shell/record+probe_libc_inet_pton.sh: 30: ./tests/shell/record+probe_libc_inet_pton.sh: expected[3]=.*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$: not found
 ping 31963 [004] 83577.670613: probe_libc:inet_pton: (7fe15f87f4b0)
 ./tests/shell/record+probe_libc_inet_pton.sh: 39: ./tests/shell/record+probe_libc_inet_pton.sh: Bad substitution
 ./tests/shell/record+probe_libc_inet_pton.sh: 41: ./tests/shell/record+probe_libc_inet_pton.sh: Bad substitution
 test child finished with -2
 ---- end ----
 probe libc's inet_pton & backtrace it with ping: Skip

AFTER:

 $ sudo perf test -v 64
 64: probe libc's inet_pton & backtrace it with ping       :
 --- start ---
 test child forked, pid 32277
 ping 32295 [001] 83679.690020: probe_libc:inet_pton: (7ff244f504b0)
 7ff244f504b0 __GI___inet_pton+0x0 (/lib/x86_64-linux-gnu/libc-2.27.so)
 7ff244f14ce4 getaddrinfo+0x124 (/lib/x86_64-linux-gnu/libc-2.27.so)
 556ac036b57d _init+0xb75 (/bin/ping)
 test child finished with 0
 ---- end ----
 probe libc's inet_pton & backtrace it with ping: Ok

Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan@linux.vnet.ibm.com>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20180629124643.2089b3ce59960eba34e87b27@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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

@@ -14,35 +14,40 @@ libc=$(grep -w libc /proc/self/maps | head -1 | sed -r 's/.*[[:space:]](\/.*)/\1
 nm -Dg $libc 2>/dev/null | fgrep -q inet_pton || exit 254
 
 trace_libc_inet_pton_backtrace() {
-	idx=0
-	expected[0]="ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\)"
-	expected[1]=".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$"
+
+	expected=`mktemp -u /tmp/expected.XXX`
+
+	echo "ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\)" > $expected
+	echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
 	case "$(uname -m)" in
 	s390x)
 		eventattr='call-graph=dwarf,max-stack=4'
-		expected[2]="gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$"
-		expected[3]="(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$"
-		expected[4]="main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$"
+		echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
+		echo "(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
+		echo "main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
 		;;
 	*)
 		eventattr='max-stack=3'
-		expected[2]="getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$"
-		expected[3]=".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$"
+		echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
+		echo ".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
 		;;
 	esac
 
-	file=`mktemp -u /tmp/perf.data.XXX`
+	perf_data=`mktemp -u /tmp/perf.data.XXX`
+	perf_script=`mktemp -u /tmp/perf.script.XXX`
+	perf record -e probe_libc:inet_pton/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1
+	perf script -i $perf_data > $perf_script
 
-	perf record -e probe_libc:inet_pton/$eventattr/ -o $file ping -6 -c 1 ::1 > /dev/null 2>&1
-	perf script -i $file | while read line ; do
+	exec 3<$perf_script
+	exec 4<$expected
+	while read line <&3 && read -r pattern <&4; do
+		[ -z "$pattern" ] && break
 		echo $line
-		echo "$line" | egrep -q "${expected[$idx]}"
+		echo "$line" | egrep -q "$pattern"
 		if [ $? -ne 0 ] ; then
-			printf "FAIL: expected backtrace entry %d \"%s\" got \"%s\"\n" $idx "${expected[$idx]}" "$line"
+			printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line"
 			exit 1
 		fi
-		let idx+=1
-		[ -z "${expected[$idx]}" ] && break
 	done
 
 	# If any statements are executed from this point onwards,
@@ -58,6 +63,6 @@ skip_if_no_perf_probe && \
 perf probe -q $libc inet_pton && \
 trace_libc_inet_pton_backtrace
 err=$?
-rm -f ${file}
+rm -f ${perf_data} ${perf_script} ${expected}
 perf probe -q -d probe_libc:inet_pton
 exit $err