[kunit,1/3] kunit: add debugfs /sys/kernel/debug/kunit/<suite>/results display

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 2dfb550..37219b8a 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -125,6 +125,8 @@  struct kunit_case {
 	bool success;
 };
 
+#define	kunit_status2str(status)	(status ? "ok" : "not ok")
+
 /**
  * KUNIT_CASE - A helper for creating a &struct kunit_case
  *
@@ -157,6 +159,9 @@  struct kunit_suite {
 	int (*init)(struct kunit *test);
 	void (*exit)(struct kunit *test);
 	struct kunit_case *test_cases;
+
+	/* private - internal use only */
+	struct dentry *debugfs;
 };
 
 /**
@@ -197,6 +202,15 @@  struct kunit {
 
 int kunit_run_tests(struct kunit_suite *suite);
 
+size_t kunit_suite_num_test_cases(struct kunit_suite *suite);
+
+unsigned int kunit_test_case_num(struct kunit_suite *suite,
+				 struct kunit_case *test_case);
+
+int __kunit_test_suites_init(struct kunit_suite **suites);
+
+void __kunit_test_suites_exit(struct kunit_suite **suites);
+
 /**
  * kunit_test_suites() - used to register one or more &struct kunit_suite
  *			 with KUnit.
@@ -226,15 +240,12 @@  struct kunit {
 	static struct kunit_suite *suites[] = { __VA_ARGS__, NULL};	\
 	static int kunit_test_suites_init(void)				\
 	{								\
-		unsigned int i;						\
-		for (i = 0; suites[i] != NULL; i++)			\
-			kunit_run_tests(suites[i]);			\
-		return 0;						\
+		return __kunit_test_suites_init(suites);		\
 	}								\
 	late_initcall(kunit_test_suites_init);				\
 	static void __exit kunit_test_suites_exit(void)			\
 	{								\
-		return;							\
+		return __kunit_test_suites_exit(suites);		\
 	}								\
 	module_exit(kunit_test_suites_exit)
 
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index fab5564..869aab0 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -3,7 +3,8 @@  obj-$(CONFIG_KUNIT) +=			kunit.o
 kunit-objs +=				test.o \
 					string-stream.o \
 					assert.o \
-					try-catch.o
+					try-catch.o \
+					debugfs.o
 
 obj-$(CONFIG_KUNIT_TEST) +=		kunit-test.o
 
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
new file mode 100644
index 0000000..5994f32
--- /dev/null
+++ b/lib/kunit/debugfs.c
@@ -0,0 +1,111 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ *    Author: Alan Maguire <alan.maguire@oracle.com>
+ */
+#include <asm/unistd.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/time.h>
+
+#include <uapi/linux/limits.h>
+#include <kunit/test.h>
+
+#include "string-stream.h"
+
+#define KUNIT_DEBUGFS_ROOT             "kunit"
+#define KUNIT_DEBUGFS_RESULTS          "results"
+
+/*
+ * Create a debugfs representation of test suites:
+ *
+ * Path						Semantics
+ * /sys/kernel/debug/kunit/<testsuite>/results	Show results of last run for
+ *						testsuite
+ *
+ */
+
+static struct dentry *debugfs_rootdir;
+
+void debugfs_cleanup(void)
+{
+	debugfs_remove(debugfs_rootdir);
+}
+
+int debugfs_init(void)
+{
+	if (!debugfs_rootdir)
+		debugfs_rootdir = debugfs_create_dir(KUNIT_DEBUGFS_ROOT, NULL);
+	if (IS_ERR(debugfs_rootdir))
+		return PTR_ERR(debugfs_rootdir);
+	return 0;
+}
+
+static void debugfs_print_result(struct seq_file *seq,
+				 struct kunit_suite *suite,
+				 struct kunit_case *test_case)
+{
+	if (!test_case)
+		return;
+
+	seq_printf(seq, "\t%s %d - %s\n", kunit_status2str(test_case->success),
+		   kunit_test_case_num(suite, test_case), test_case->name);
+}
+
+/*
+ * /sys/kernel/debug/kunit/<testsuite>/results shows all results for testsuite.
+ */
+static int debugfs_print_results(struct seq_file *seq, void *v)
+{
+	struct kunit_suite *suite = (struct kunit_suite *)seq->private;
+	struct kunit_case *test_case;
+
+	if (!suite)
+		return 0;
+
+	seq_printf(seq, "\t# Subtest: %s\n", suite->name);
+	seq_printf(seq, "\t1..%zd\n", kunit_suite_num_test_cases(suite));
+
+	for (test_case = suite->test_cases; test_case->run_case; test_case++)
+		debugfs_print_result(seq, suite, test_case);
+
+	return 0;
+}
+
+static int debugfs_release(struct inode *inode, struct file *file)
+{
+	return single_release(inode, file);
+}
+
+static int debugfs_results_open(struct inode *inode, struct file *file)
+{
+	struct kunit_suite *suite;
+
+	suite = (struct kunit_suite *)inode->i_private;
+
+	return single_open(file, debugfs_print_results, suite);
+}
+
+static const struct file_operations debugfs_results_fops = {
+	.open = debugfs_results_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = debugfs_release,
+};
+
+void debugfs_create_suite(struct kunit_suite *suite)
+{
+	/* First add /sys/kernel/debug/kunit/<testsuite> */
+	suite->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir);
+	if (IS_ERR(suite->debugfs))
+		return;
+
+	debugfs_create_file(KUNIT_DEBUGFS_RESULTS, S_IFREG | 0444,
+			    suite->debugfs,
+			    suite, &debugfs_results_fops);
+}
+
+void debugfs_destroy_suite(struct kunit_suite *suite)
+{
+	debugfs_remove_recursive(suite->debugfs);
+}
diff --git a/lib/kunit/debugfs.h b/lib/kunit/debugfs.h
new file mode 100644
index 0000000..d74e8a4
--- /dev/null
+++ b/lib/kunit/debugfs.h
@@ -0,0 +1,11 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020, Oracle and/or its affiliates.
+ */
+
+#include <kunit/test.h>
+
+void debugfs_create_suite(struct kunit_suite *suite);
+void debugfs_destroy_suite(struct kunit_suite *suite);
+int debugfs_init(void);
+void debugfs_cleanup(void);
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 9242f93..efb05ba 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -10,6 +10,7 @@ 
 #include <linux/kernel.h>
 #include <linux/sched/debug.h>
 
+#include "debugfs.h"
 #include "string-stream.h"
 #include "try-catch-impl.h"
 
@@ -28,22 +29,24 @@  static void kunit_print_tap_version(void)
 	}
 }
 
-static size_t kunit_test_cases_len(struct kunit_case *test_cases)
+size_t kunit_suite_num_test_cases(struct kunit_suite *suite)
 {
-	struct kunit_case *test_case;
+	struct kunit_case *test_case, *test_cases = suite->test_cases;
 	size_t len = 0;
 
-	for (test_case = test_cases; test_case->run_case; test_case++)
+	for (test_case = test_cases; test_case && test_case->run_case;
+	     test_case++)
 		len++;
 
 	return len;
 }
+EXPORT_SYMBOL_GPL(kunit_suite_num_test_cases);
 
 static void kunit_print_subtest_start(struct kunit_suite *suite)
 {
 	kunit_print_tap_version();
 	pr_info("\t# Subtest: %s\n", suite->name);
-	pr_info("\t1..%zd\n", kunit_test_cases_len(suite->test_cases));
+	pr_info("\t1..%zd\n", kunit_suite_num_test_cases(suite));
 }
 
 static void kunit_print_ok_not_ok(bool should_indent,
@@ -51,19 +54,15 @@  static void kunit_print_ok_not_ok(bool should_indent,
 				  size_t test_number,
 				  const char *description)
 {
-	const char *indent, *ok_not_ok;
+	const char *indent;
 
 	if (should_indent)
 		indent = "\t";
 	else
 		indent = "";
 
-	if (is_ok)
-		ok_not_ok = "ok";
-	else
-		ok_not_ok = "not ok";
-
-	pr_info("%s%s %zd - %s\n", indent, ok_not_ok, test_number, description);
+	pr_info("%s%s %zd - %s\n", indent, kunit_status2str(is_ok),
+		test_number, description);
 }
 
 static bool kunit_suite_has_succeeded(struct kunit_suite *suite)
@@ -87,14 +86,20 @@  static void kunit_print_subtest_end(struct kunit_suite *suite)
 			      suite->name);
 }
 
-static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
-					    size_t test_number)
+unsigned int kunit_test_case_num(struct kunit_suite *suite,
+				 struct kunit_case *test_case)
 {
-	kunit_print_ok_not_ok(true,
-			      test_case->success,
-			      test_number,
-			      test_case->name);
+	struct kunit_case *tc;
+	unsigned int i;
+
+	for (i = 1, tc = suite->test_cases; tc->run_case; tc++, i++) {
+		if (tc == test_case)
+			return i;
+	}
+
+	return 0;
 }
+EXPORT_SYMBOL_GPL(kunit_test_case_num);
 
 static void kunit_print_string_stream(struct kunit *test,
 				      struct string_stream *stream)
@@ -102,6 +107,9 @@  static void kunit_print_string_stream(struct kunit *test,
 	struct string_stream_fragment *fragment;
 	char *buf;
 
+	if (string_stream_is_empty(stream))
+		return;
+
 	buf = string_stream_get_string(stream);
 	if (!buf) {
 		kunit_err(test,
@@ -303,19 +311,20 @@  static void kunit_run_case_catch_errors(struct kunit_suite *suite,
 	kunit_try_catch_run(try_catch, &context);
 
 	test_case->success = test.success;
+
+	kunit_print_ok_not_ok(true, test_case->success,
+			      kunit_test_case_num(suite, test_case),
+			      test_case->name);
 }
 
 int kunit_run_tests(struct kunit_suite *suite)
 {
 	struct kunit_case *test_case;
-	size_t test_case_count = 1;
 
 	kunit_print_subtest_start(suite);
 
-	for (test_case = suite->test_cases; test_case->run_case; test_case++) {
+	for (test_case = suite->test_cases; test_case->run_case; test_case++)
 		kunit_run_case_catch_errors(suite, test_case);
-		kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
-	}
 
 	kunit_print_subtest_end(suite);
 
@@ -323,6 +332,37 @@  int kunit_run_tests(struct kunit_suite *suite)
 }
 EXPORT_SYMBOL_GPL(kunit_run_tests);
 
+static void kunit_init_suite(struct kunit_suite *suite)
+{
+	debugfs_create_suite(suite);
+}
+
+int __kunit_test_suites_init(struct kunit_suite **suites)
+{
+	unsigned int i;
+
+	for (i = 0; suites[i] != NULL; i++) {
+		kunit_init_suite(suites[i]);
+		kunit_run_tests(suites[i]);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__kunit_test_suites_init);
+
+static void kunit_exit_suite(struct kunit_suite *suite)
+{
+	debugfs_destroy_suite(suite);
+}
+
+void __kunit_test_suites_exit(struct kunit_suite **suites)
+{
+	unsigned int i;
+
+	for (i = 0; suites[i] != NULL; i++)
+		kunit_exit_suite(suites[i]);
+}
+EXPORT_SYMBOL_GPL(__kunit_test_suites_exit);
+
 struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
 						    kunit_resource_init_t init,
 						    kunit_resource_free_t free,
@@ -398,6 +438,9 @@  int kunit_resource_destroy(struct kunit *test,
 {
 	struct kunit_resource *resource;
 
+	if (!test)
+		kfree(match_data);
+
 	resource = kunit_resource_remove(test, match, free, match_data);
 
 	if (!resource)
@@ -489,12 +532,13 @@  void kunit_cleanup(struct kunit *test)
 
 static int __init kunit_init(void)
 {
-	return 0;
+	return debugfs_init();
 }
 late_initcall(kunit_init);
 
 static void __exit kunit_exit(void)
 {
+	debugfs_cleanup();
 }
 module_exit(kunit_exit);