kunit: test: create a single centralized executor for all tests

Add a centralized executor to dispatch tests rather than relying on
late_initcall to schedule each test suite separately. Centralized
execution is for built-in tests only; modules will execute tests when
loaded.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Co-developed-by: Iurii Zaikin <yzaikin@google.com>
Signed-off-by: Iurii Zaikin <yzaikin@google.com>
Co-developed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/kunit/executor.c

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <kunit/test.h>
+
+/*
+ * These symbols point to the .kunit_test_suites section and are defined in
+ * include/asm-generic/vmlinux.lds.h, and consequently must be extern.
+ */
+extern struct kunit_suite * const * const __kunit_suites_start[];
+extern struct kunit_suite * const * const __kunit_suites_end[];
+
+#if IS_BUILTIN(CONFIG_KUNIT)
+
+static int kunit_run_all_tests(void)
+{
+	struct kunit_suite * const * const *suites;
+
+	for (suites = __kunit_suites_start;
+	     suites < __kunit_suites_end;
+	     suites++)
+			__kunit_test_suites_init(*suites);
+
+	return 0;
+}
+
+late_initcall(kunit_run_all_tests);
+
+#endif /* IS_BUILTIN(CONFIG_KUNIT) */