selftests: ftrace: Add a testcase for string type with kprobe_event

#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: Kprobe event string type argument

[ -f kprobe_events ] || exit_unsupported # this is configurable

echo 0 > events/enable

echo > kprobe_events

case `uname -m` in

x86_64)

  ARG2=%si

  OFFS=8

;;

i[3456]86)

  ARG2=%cx

  OFFS=4

;;

aarch64)

  ARG2=%x1

  OFFS=8

;;

arm*)

  ARG2=%r1

  OFFS=4

;;

*)

  echo "Please implement other architecture here"

  exit_untested

esac

: "Test get argument (1)"

echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string" > kprobe_events

echo 1 > events/kprobes/testprobe/enable

! echo test >> kprobe_events

tail -n 1 trace | grep -qe "testprobe.* arg1=\"test\""

echo 0 > events/kprobes/testprobe/enable

: "Test get argument (2)"

echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string arg2=+0(+${OFFS}(${ARG2})):string" > kprobe_events

echo 1 > events/kprobes/testprobe/enable

! echo test1 test2 >> kprobe_events

tail -n 1 trace | grep -qe "testprobe.* arg1=\"test1\" arg2=\"test2\""

echo 0 > events/enable

echo > kprobe_events