[PATCH v3 8/9] selftests/ftrace: Add BTF fields access testcases

Masami Hiramatsu (Google)
2023-07-26T13:01:47Z

Add test cases for accessing the data structure fields using BTF info.
This includes the field access from parameters and retval, and accessing
string information.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
---
Changes in v2:
- Use '$retval' instead of 'retval'.
- Add a test that use both '$retval' and '$arg1' for fprobe.
Changes in v3:
- Change a test case with a numeric value.
- Add a test case with mixed '.' and '->' operators.
---
.../ftrace/test.d/dynevent/add_remove_btfarg.tc | 14 ++++++++++++++
.../ftrace/test.d/dynevent/fprobe_syntax_errors.tc | 4 ++++
2 files changed, 18 insertions(+)

diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_btfarg.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_btfarg.tc
index f34b14ef9781..4bfd2f45db42 100644
--- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_btfarg.tc
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_btfarg.tc
@@ -21,6 +21,9 @@ echo 0 > events/enable
echo > dynamic_events

TP=kfree
+TP2=kmem_cache_alloc
+TP3=getname_flags
+TP4=sched_wakeup

if [ "$FPROBES" ] ; then
echo "f:fpevent $TP object" >> dynamic_events
@@ -33,6 +36,7 @@ echo > dynamic_events

echo "f:fpevent $TP "'$arg1' >> dynamic_events
grep -q "fpevent.*object=object" dynamic_events
+
echo > dynamic_events

echo "f:fpevent $TP "'$arg*' >> dynamic_events
@@ -45,6 +49,16 @@ fi

echo > dynamic_events

+echo "t:tpevent ${TP2} obj_size=s->object_size" >> dynamic_events
+echo "f:fpevent ${TP3}%return path=\$retval->name:string" >> dynamic_events
+echo "t:tpevent2 ${TP4} p->se.group_node.next->prev" >> dynamic_events
+
+grep -q "tpevent .*obj_size=s->object_size" dynamic_events
+grep -q "fpevent.*path=\$retval->name:string" dynamic_events
+grep -q 'tpevent2 .*p->se.group_node.next->prev' dynamic_events
+
+echo > dynamic_events
+
if [ "$KPROBES" ] ; then
echo "p:kpevent $TP object" >> dynamic_events
grep -q "kpevent.*object=object" dynamic_events
diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc
index 72563b2e0812..49758f77c923 100644
--- a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc
@@ -103,6 +103,10 @@ check_error 'f vfs_read%return ^$arg*' # NOFENTRY_ARGS
check_error 'f vfs_read ^hoge' # NO_BTFARG
check_error 'f kfree ^$arg10' # NO_BTFARG (exceed the number of parameters)
check_error 'f kfree%return ^$retval' # NO_RETVAL
+check_error 'f vfs_read%return $retval->^foo' # NO_PTR_STRCT
+check_error 'f vfs_read file->^foo' # NO_BTF_FIELD
+check_error 'f vfs_read file^-.foo' # BAD_HYPHEN
+check_error 'f vfs_read ^file:string' # BAD_TYPE4STR
else
check_error 'f vfs_read ^$arg*' # NOSUP_BTFARG
check_error 't kfree ^$arg*' # NOSUP_BTFARG