[PATCH bpf-next v3 2/3] selftests/bpf: skip recursive functions for kprobe_multi

[Menglong Dong <menglong8.dong@gmail.com>]

Some functions is recursive for the kprobe_multi and impact the benchmark
results. So just skip them.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
v2:
- introduce trace_blacklist instead of copy-pasting strcmp
---
 tools/testing/selftests/bpf/trace_helpers.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index d24baf244d1f..9577979bd84d 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -19,6 +19,7 @@
 #include <gelf.h>
 #include "bpf/hashmap.h"
 #include "bpf/libbpf_internal.h"
+#include "bpf_util.h"
 
 #define TRACEFS_PIPE	"/sys/kernel/tracing/trace_pipe"
 #define DEBUGFS_PIPE	"/sys/kernel/debug/tracing/trace_pipe"
@@ -540,8 +541,20 @@ static bool is_invalid_entry(char *buf, bool kernel)
 	return false;
 }
 
+static const char * const trace_blacklist[] = {
+	"migrate_disable",
+	"migrate_enable",
+	"rcu_read_unlock_strict",
+	"preempt_count_add",
+	"preempt_count_sub",
+	"__rcu_read_lock",
+	"__rcu_read_unlock",
+};
+
 static bool skip_entry(char *name)
 {
+	int i;
+
 	/*
 	 * We attach to almost all kernel functions and some of them
 	 * will cause 'suspicious RCU usage' when fprobe is attached
@@ -559,6 +572,12 @@ static bool skip_entry(char *name)
 	if (!strncmp(name, "__ftrace_invalid_address__",
 		     sizeof("__ftrace_invalid_address__") - 1))
 		return true;
+
+	for (i = 0; i < ARRAY_SIZE(trace_blacklist); i++) {
+		if (!strcmp(name, trace_blacklist[i]))
+			return true;
+	}
+
 	return false;
 }
 
-- 
2.51.0