kunit: Add "hooks" to call into KUnit when it's built as a module

KUnit has several macros and functions intended for use from non-test
code. These hooks, currently the kunit_get_current_test() and
kunit_fail_current_test() macros, didn't work when CONFIG_KUNIT=m.

In order to support this case, the required functions and static data
need to be available unconditionally, even when KUnit itself is not
built-in. The new 'hooks.c' file is therefore always included, and has
both the static key required for kunit_get_current_test(), and a table
of function pointers in struct kunit_hooks_table. This is filled in with
the real implementations by kunit_install_hooks(), which is kept in
hooks-impl.h and called when the kunit module is loaded.

This can  be extended for future features which require similar
"hook" behaviour, such as static stubs, by simply adding new entries to
the struct, and the appropriate code to set them.

Fixed white-space errors during commit:
Shuah Khan <skhan@linuxfoundation.org>

Resolved merge conflicts with:
db105c37a4d6 ("kunit: Export kunit_running()")
This patch supersedes the above.
Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

1 files changed, 7 insertions, 8 deletions

diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 890ba5b3a981..51cae59d8aae 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -17,17 +17,14 @@
 #include <linux/sched.h>
 
 #include "debugfs.h"
+#include "hooks-impl.h"
 #include "string-stream.h"
 #include "try-catch-impl.h"
 
-DEFINE_STATIC_KEY_FALSE(kunit_running);
-EXPORT_SYMBOL_GPL(kunit_running);
-
-#if IS_BUILTIN(CONFIG_KUNIT)
 /*
- * Fail the current test and print an error message to the log.
+ * Hook to fail the current test and print an error message to the log.
  */
-void __kunit_fail_current_test(const char *file, int line, const char *fmt, ...)
+void __kunit_fail_current_test_impl(const char *file, int line, const char *fmt, ...)
 {
 	va_list args;
 	int len;
@@ -54,8 +51,6 @@ void __kunit_fail_current_test(const char *file, int line, const char *fmt, ...)
 	kunit_err(current->kunit_test, "%s:%d: %s", file, line, buffer);
 	kunit_kfree(current->kunit_test, buffer);
 }
-EXPORT_SYMBOL_GPL(__kunit_fail_current_test);
-#endif
 
 /*
  * Enable KUnit tests to run.
@@ -778,6 +773,9 @@ EXPORT_SYMBOL_GPL(kunit_cleanup);
 
 static int __init kunit_init(void)
 {
+	/* Install the KUnit hook functions. */
+	kunit_install_hooks();
+
 	kunit_debugfs_init();
 #ifdef CONFIG_MODULES
 	return register_module_notifier(&kunit_mod_nb);
@@ -789,6 +787,7 @@ late_initcall(kunit_init);
 
 static void __exit kunit_exit(void)
 {
+	memset(&kunit_hooks, 0, sizeof(kunit_hooks));
 #ifdef CONFIG_MODULES
 	unregister_module_notifier(&kunit_mod_nb);
 #endif