lib/test_fprobe: Add private entry_data testcases

Add test cases for checking whether private entry_data is
correctly passed or not.

Link: https://lkml.kernel.org/r/167526697074.433354.17790288501657876219.stgit@mhiramat.roam.corp.google.com

Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

lib/test_fprobe.c

@@ -38,6 +38,12 @@ static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip,
 	if (ip != target_ip)
 		KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
 	entry_val = (rand1 / div_factor);
+	if (fp->entry_data_size) {
+		KUNIT_EXPECT_NOT_NULL(current_test, data);
+		if (data)
+			*(u32 *)data = entry_val;
+	} else
+		KUNIT_EXPECT_NULL(current_test, data);
 }
 
 static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
@@ -53,6 +59,12 @@ static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
 		KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor));
 	KUNIT_EXPECT_EQ(current_test, entry_val, (rand1 / div_factor));
 	exit_val = entry_val + div_factor;
+	if (fp->entry_data_size) {
+		KUNIT_EXPECT_NOT_NULL(current_test, data);
+		if (data)
+			KUNIT_EXPECT_EQ(current_test, *(u32 *)data, entry_val);
+	} else
+		KUNIT_EXPECT_NULL(current_test, data);
 }
 
 /* Test entry only (no rethook) */
@@ -134,6 +146,23 @@ static void test_fprobe_syms(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
 }
 
+/* Test private entry_data */
+static void test_fprobe_data(struct kunit *test)
+{
+	struct fprobe fp = {
+		.entry_handler = fp_entry_handler,
+		.exit_handler = fp_exit_handler,
+		.entry_data_size = sizeof(u32),
+	};
+
+	current_test = test;
+	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
+
+	target(rand1);
+
+	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
+}
+
 static unsigned long get_ftrace_location(void *func)
 {
 	unsigned long size, addr = (unsigned long)func;
@@ -159,6 +188,7 @@ static struct kunit_case fprobe_testcases[] = {
 	KUNIT_CASE(test_fprobe_entry),
 	KUNIT_CASE(test_fprobe),
 	KUNIT_CASE(test_fprobe_syms),
+	KUNIT_CASE(test_fprobe_data),
 	{}
 };