kunit: allow kunit tests to be loaded as a module

As tests are added to kunit, it will become less feasible to execute
all built tests together.  By supporting modular tests we provide
a simple way to do selective execution on a running system; specifying

CONFIG_KUNIT=y
CONFIG_KUNIT_EXAMPLE_TEST=m

...means we can simply "insmod example-test.ko" to run the tests.

To achieve this we need to do the following:

o export the required symbols in kunit
o string-stream tests utilize non-exported symbols so for now we skip
  building them when CONFIG_KUNIT_TEST=m.
o drivers/base/power/qos-test.c contains a few unexported interface
  references, namely freq_qos_read_value() and freq_constraints_init().
  Both of these could be potentially defined as static inline functions
  in include/linux/pm_qos.h, but for now we simply avoid supporting
  module build for that test suite.
o support a new way of declaring test suites.  Because a module cannot
  do multiple late_initcall()s, we provide a kunit_test_suites() macro
  to declare multiple suites within the same module at once.
o some test module names would have been too general ("test-test"
  and "example-test" for kunit tests, "inode-test" for ext4 tests);
  rename these as appropriate ("kunit-test", "kunit-example-test"
  and "ext4-inode-test" respectively).

Also define kunit_test_suite() via kunit_test_suites()
as callers in other trees may need the old definition.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits
Acked-by: David Gow <davidgow@google.com> # For list-test
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
index 4a66d1684b46..0247a281431a 100644
--- a/lib/kunit/try-catch.c
+++ b/lib/kunit/try-catch.c
@@ -20,6 +20,7 @@ void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)
 	try_catch->try_result = -EFAULT;
 	complete_and_exit(try_catch->try_completion, -EFAULT);
 }
+EXPORT_SYMBOL_GPL(kunit_try_catch_throw);
 
 static int kunit_generic_run_threadfn_adapter(void *data)
 {
@@ -107,3 +108,4 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
 
 	try_catch->catch(try_catch->context);
 }
+EXPORT_SYMBOL_GPL(kunit_try_catch_run);