lib/test_fprobe: Add a testcase for skipping exit_handler

Add a testcase for skipping exit_handler if entry_handler
returns !0.

Link: https://lkml.kernel.org/r/167526700658.433354.12922388040490848613.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>

diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c
index 9fa2ac9eda83f59086c47c68e42419cf2f17ca2b..0fe5273e960bb4d07b5c3a4613d8d70c1d2f6d95 100644 (file)
--- a/lib/test_fprobe.c
+++ b/lib/test_fprobe.c
@@ -21,6 +21,7 @@ static u32 (*target_nest)(u32 value, u32 (*nest)(u32));
 static unsigned long target_ip;
 static unsigned long target2_ip;
 static unsigned long target_nest_ip;
+static int entry_return_value;
 
 static noinline u32 fprobe_selftest_target(u32 value)
 {
@@ -52,7 +53,7 @@ static notrace int fp_entry_handler(struct fprobe *fp, unsigned long ip,
        } else
                KUNIT_EXPECT_NULL(current_test, data);
 
-       return 0;
+       return entry_return_value;
 }
 
 static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
@@ -205,6 +206,28 @@ static void test_fprobe_nest(struct kunit *test)
        KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
 }
 
+static void test_fprobe_skip(struct kunit *test)
+{
+       struct fprobe fp = {
+               .entry_handler = fp_entry_handler,
+               .exit_handler = fp_exit_handler,
+       };
+
+       current_test = test;
+       KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
+
+       entry_return_value = 1;
+       entry_val = 0;
+       exit_val = 0;
+       target(rand1);
+       KUNIT_EXPECT_NE(test, 0, entry_val);
+       KUNIT_EXPECT_EQ(test, 0, exit_val);
+       KUNIT_EXPECT_EQ(test, 0, fp.nmissed);
+       entry_return_value = 0;
+
+       KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
+}
+
 static unsigned long get_ftrace_location(void *func)
 {
        unsigned long size, addr = (unsigned long)func;
@@ -234,6 +257,7 @@ static struct kunit_case fprobe_testcases[] = {
        KUNIT_CASE(test_fprobe_syms),
        KUNIT_CASE(test_fprobe_data),
        KUNIT_CASE(test_fprobe_nest),
+       KUNIT_CASE(test_fprobe_skip),
        {}
 };