On Fri, 21 Jul 2023 00:00:32 +0100
Alan Maguire [off-list ref] wrote:

On 17/07/2023 16:24, Masami Hiramatsu (Google) wrote:

quoted

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

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>

One suggestion below, but

Reviewed-by: Alan Maguire <redacted>

Thanks

quoted

---
Changes in v2:
 - Use '$retval' instead of 'retval'.
 - Add a test that use both '$retval' and '$arg1' for fprobe.
---
 .../ftrace/test.d/dynevent/add_remove_btfarg.tc    |   11 +++++++++++
 .../ftrace/test.d/dynevent/fprobe_syntax_errors.tc |    4 ++++
 2 files changed, 15 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 b89de1771655..93b94468967b 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 +21,8 @@ echo 0 > events/enable
 echo > dynamic_events
 
 TP=kfree
+TP2=kmem_cache_alloc
+TP3=getname_flags
 
 if [ "$FPROBES" ] ; then
 echo "f:fpevent $TP object" >> dynamic_events

@@ -33,6 +35,7 @@ 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 +48,14 @@ fi
 
 echo > dynamic_events
 
+echo "t:tpevent $TP2 name=s->name:string" >> dynamic_events
+echo "f:fpevent ${TP3}%return path=\$retval->name:string" >> dynamic_events
+

could we test a numeric value like kmem_cache_alloc object size?
also if combos of -> and . are allowed, would be good to test one of
those too.

OK, that's a good point! I'll add it.

quoted

+grep -q "tpevent.*name=s->name:string" dynamic_events
+grep -q "fpevent.*path=\$retval->name:string" 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

-- 
Masami Hiramatsu (Google) [off-list ref]