Re: [lkp-robot] [tracing] ecadccb31b: kernel_selftests.ftrace.ftracetest.fail

[Masami Hiramatsu <mhiramat@kernel.org>]

On Sat, 21 Jul 2018 18:40:32 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:

> Hi,
> 
> OK, I'll handle this.
> The reason why this error is that kprobe event tests probe ftrace itself for test.

So one possible fix is below patch.

Another possible way to fix is to allow instrumentation on trace_kprobe.c as
same as trace_selftest_dynamic.c .

Thank you,

-----
selftests/ftrace: Fix kprobe string testcase to not probe notrace function

From: Masami Hiramatsu <mhiramat@kernel.org>

Fix kprobe string argument testcase to not probe notrace
function. Instead, it probes tracefs function which must
be available with ftrace.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 .../ftrace/test.d/kprobe/kprobe_args_string.tc     |   30 ++++++++------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc
index a000256..1ad70cd 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc
@@ -9,28 +9,22 @@ echo > kprobe_events
 
 case `uname -m` in
 x86_64)
-  ARG2=%si
-  OFFS=8
+  ARG1=%di
 ;;
 i[3456]86)
-  ARG2=%cx
-  OFFS=4
+  ARG1=%ax
 ;;
 aarch64)
-  ARG2=%x1
-  OFFS=8
+  ARG1=%x0
 ;;
 arm*)
-  ARG2=%r1
-  OFFS=4
+  ARG1=%r0
 ;;
 ppc64*)
-  ARG2=%r4
-  OFFS=8
+  ARG1=%r3
 ;;
 ppc*)
-  ARG2=%r4
-  OFFS=4
+  ARG1=%r3
 ;;
 *)
   echo "Please implement other architecture here"
@@ -38,17 +32,17 @@ ppc*)
 esac
 
 : "Test get argument (1)"
-echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string" > kprobe_events
+echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):string" > kprobe_events
 echo 1 > events/kprobes/testprobe/enable
-! echo test >> kprobe_events
-tail -n 1 trace | grep -qe "testprobe.* arg1=\"test\""
+echo "p:test _do_fork" >> kprobe_events
+grep -qe "testprobe.* arg1=\"test\"" trace
 
 echo 0 > events/kprobes/testprobe/enable
 : "Test get argument (2)"
-echo "p:testprobe create_trace_kprobe arg1=+0(+0(${ARG2})):string arg2=+0(+${OFFS}(${ARG2})):string" > kprobe_events
+echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):string arg2=+0(${ARG1}):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 "p:test _do_fork" >> kprobe_events
+grep -qe "testprobe.* arg1=\"test\" arg2=\"test\"" trace
 
 echo 0 > events/enable
 echo > kprobe_events