[v5,linux-kselftest-test,3/6] kunit: allow kunit tests to be loaded as a module
diff mbox series

Message ID 1575374868-32601-4-git-send-email-alan.maguire@oracle.com
State New
Headers show
Series
  • kunit: support building core/tests as modules
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Commit Message

Alan Maguire Dec. 3, 2019, 12:07 p.m. UTC
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 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).

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>
---
 fs/ext4/Kconfig                                    |  2 +-
 fs/ext4/Makefile                                   |  5 ++++
 fs/ext4/inode-test.c                               |  4 ++-
 include/kunit/test.h                               | 35 +++++++++++++++-------
 kernel/sysctl-test.c                               |  4 ++-
 lib/Kconfig.debug                                  |  4 +--
 lib/kunit/Kconfig                                  |  4 +--
 lib/kunit/Makefile                                 | 10 +++++--
 lib/kunit/assert.c                                 |  8 +++++
 lib/kunit/{example-test.c => kunit-example-test.c} |  4 ++-
 lib/kunit/{test-test.c => kunit-test.c}            |  5 ++--
 lib/kunit/string-stream-test.c                     |  2 +-
 lib/kunit/test.c                                   |  8 +++++
 lib/kunit/try-catch.c                              |  2 ++
 lib/list-test.c                                    |  4 ++-
 15 files changed, 76 insertions(+), 25 deletions(-)
 rename lib/kunit/{example-test.c => kunit-example-test.c} (97%)
 rename lib/kunit/{test-test.c => kunit-test.c} (98%)

Comments

Brendan Higgins Dec. 3, 2019, 5:54 p.m. UTC | #1
On Tue, Dec 3, 2019 at 4:08 AM Alan Maguire <alan.maguire@oracle.com> wrote:
>
> 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 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).
>
> 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>

> ---
>  fs/ext4/Kconfig                                    |  2 +-
>  fs/ext4/Makefile                                   |  5 ++++
>  fs/ext4/inode-test.c                               |  4 ++-
>  include/kunit/test.h                               | 35 +++++++++++++++-------
>  kernel/sysctl-test.c                               |  4 ++-
>  lib/Kconfig.debug                                  |  4 +--
>  lib/kunit/Kconfig                                  |  4 +--
>  lib/kunit/Makefile                                 | 10 +++++--
>  lib/kunit/assert.c                                 |  8 +++++
>  lib/kunit/{example-test.c => kunit-example-test.c} |  4 ++-
>  lib/kunit/{test-test.c => kunit-test.c}            |  5 ++--
>  lib/kunit/string-stream-test.c                     |  2 +-
>  lib/kunit/test.c                                   |  8 +++++
>  lib/kunit/try-catch.c                              |  2 ++
>  lib/list-test.c                                    |  4 ++-
>  15 files changed, 76 insertions(+), 25 deletions(-)
>  rename lib/kunit/{example-test.c => kunit-example-test.c} (97%)
>  rename lib/kunit/{test-test.c => kunit-test.c} (98%)

Ted, David, and Iurii, can you each review/ack for the bits that each
of you own?

Thanks for all your hard work on this Alan!
Iurii Zaikin Dec. 4, 2019, 12:17 a.m. UTC | #2
> +ifeq ($(CONFIG_EXT4_KUNIT_TESTS),y)
>  ext4-$(CONFIG_EXT4_KUNIT_TESTS)                += inode-test.o
> +else
> +obj-$(CONFIG_EXT4_KUNIT_TESTS)         += ext4-inode-test.o
> +ext4-inode-test-objs                   += inode-test.o
> +endif
Why not rename it unconditionally?
Theodore Y. Ts'o Dec. 4, 2019, 12:38 a.m. UTC | #3
On Tue, Dec 03, 2019 at 09:54:25AM -0800, Brendan Higgins wrote:
> On Tue, Dec 3, 2019 at 4:08 AM Alan Maguire <alan.maguire@oracle.com> wrote:
> >
> > 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 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).
> >
> > 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


I do have one question, out of curiosity --- for people who aren't
using UML to run Kunit tests, and are either running the kunit tests
during boot, or when the module is loaded, is there the test framework
to automatically extract the test reports out of dmesg?

I can boot a kernel with kunit tests enabled using kvm, and I see it
splatted intermixed with the rest of the kernel boot messages.  This
is how I tested the 32-bit ext4 inode test fix.  But I had to manually
find the test output.  Is that the expected way people are supposed to
be using Kunit tests w/o using UML and the python runner?

Thanks,

						- Ted
Brendan Higgins Dec. 4, 2019, 12:42 a.m. UTC | #4
On Tue, Dec 3, 2019 at 4:39 PM Theodore Y. Ts'o <tytso@mit.edu> wrote:
>
> On Tue, Dec 03, 2019 at 09:54:25AM -0800, Brendan Higgins wrote:
> > On Tue, Dec 3, 2019 at 4:08 AM Alan Maguire <alan.maguire@oracle.com> wrote:
> > >
> > > 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 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).
> > >
> > > 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
>
>
> I do have one question, out of curiosity --- for people who aren't
> using UML to run Kunit tests, and are either running the kunit tests
> during boot, or when the module is loaded, is there the test framework
> to automatically extract the test reports out of dmesg?
>
> I can boot a kernel with kunit tests enabled using kvm, and I see it
> splatted intermixed with the rest of the kernel boot messages.  This
> is how I tested the 32-bit ext4 inode test fix.  But I had to manually
> find the test output.  Is that the expected way people are supposed to
> be using Kunit tests w/o using UML and the python runner?

For now, yes. We do not currently have a piece that extracts the test
reports; however, we are planning on pulling that bit out of
tools/testing/kunit/; we just haven't gotten around to it yet.
Brendan Higgins Dec. 4, 2019, 12:51 a.m. UTC | #5
On Tue, Dec 3, 2019 at 4:42 PM Brendan Higgins
<brendanhiggins@google.com> wrote:
>
> On Tue, Dec 3, 2019 at 4:39 PM Theodore Y. Ts'o <tytso@mit.edu> wrote:
> >
> > On Tue, Dec 03, 2019 at 09:54:25AM -0800, Brendan Higgins wrote:
> > > On Tue, Dec 3, 2019 at 4:08 AM Alan Maguire <alan.maguire@oracle.com> wrote:
> > > >
> > > > 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 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).
> > > >
> > > > 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
> >
> >
> > I do have one question, out of curiosity --- for people who aren't
> > using UML to run Kunit tests, and are either running the kunit tests
> > during boot, or when the module is loaded, is there the test framework
> > to automatically extract the test reports out of dmesg?
> >
> > I can boot a kernel with kunit tests enabled using kvm, and I see it
> > splatted intermixed with the rest of the kernel boot messages.  This
> > is how I tested the 32-bit ext4 inode test fix.  But I had to manually
> > find the test output.  Is that the expected way people are supposed to
> > be using Kunit tests w/o using UML and the python runner?
>
> For now, yes. We do not currently have a piece that extracts the test
> reports; however, we are planning on pulling that bit out of
> tools/testing/kunit/; we just haven't gotten around to it yet.

I just added a bug for this here:
https://bugzilla.kernel.org/show_bug.cgi?id=205761
David Gow Dec. 4, 2019, 12:55 a.m. UTC | #6
On Tue, Dec 3, 2019 at 4:08 AM Alan Maguire <alan.maguire@oracle.com> wrote:
>
> 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 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).
>
> 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>
> ---

Acked-by: David Gow <davidgow@google.com> # For list-test
Alan Maguire Dec. 4, 2019, 3:30 p.m. UTC | #7
On Tue, 3 Dec 2019, Iurii Zaikin wrote:

> > +ifeq ($(CONFIG_EXT4_KUNIT_TESTS),y)
> >  ext4-$(CONFIG_EXT4_KUNIT_TESTS)                += inode-test.o
> > +else
> > +obj-$(CONFIG_EXT4_KUNIT_TESTS)         += ext4-inode-test.o
> > +ext4-inode-test-objs                   += inode-test.o
> > +endif
> Why not rename it unconditionally?
> 

Good point - I've fixed this in v6. Thanks for the review!

Alan
Alan Maguire Dec. 4, 2019, 3:41 p.m. UTC | #8
On Tue, 3 Dec 2019, Theodore Y. Ts'o wrote:

> On Tue, Dec 03, 2019 at 09:54:25AM -0800, Brendan Higgins wrote:
> > On Tue, Dec 3, 2019 at 4:08 AM Alan Maguire <alan.maguire@oracle.com> wrote:
> > >
> > > 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 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).
> > >
> > > 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
> 

Thanks for taking a look!

> 
> I do have one question, out of curiosity --- for people who aren't
> using UML to run Kunit tests, and are either running the kunit tests
> during boot, or when the module is loaded, is there the test framework
> to automatically extract the test reports out of dmesg?
> 
> I can boot a kernel with kunit tests enabled using kvm, and I see it
> splatted intermixed with the rest of the kernel boot messages.  This
> is how I tested the 32-bit ext4 inode test fix.  But I had to manually
> find the test output.  Is that the expected way people are supposed to
> be using Kunit tests w/o using UML and the python runner?
>

Looks like Brendan's got something coming to resolve this;
I've also got a patch that I was hoping to send out soon
that might help.  The idea is that each test suite would create
a debugfs representation under /sys/kernel/debug/kunit;
specifically:

/sys/kernel/debug/kunit/results/<suite>
/sys/kernel/debug/kunit/results/<suite>-tests

...where cat'ing the former shows the full set of results,
and the latter is a directory within which we can display
individual test results in test-case-specific files.

This is all done by ensuring that when tests log information,
they log to a per-test-case log buffer as well as to dmesg.

If the above sounds useful, I'll try and polish up the patch
for submission. Thanks!

Alan

> Thanks,
> 
> 						- Ted
>
Iurii Zaikin Dec. 5, 2019, midnight UTC | #9
> I've also got a patch that I was hoping to send out soon
> that might help.  The idea is that each test suite would create
> a debugfs representation under /sys/kernel/debug/kunit;
> specifically:
>
> /sys/kernel/debug/kunit/results/<suite>
> /sys/kernel/debug/kunit/results/<suite>-tests
>
> ...where cat'ing the former shows the full set of results,
> and the latter is a directory within which we can display
> individual test results in test-case-specific files.
>
> This is all done by ensuring that when tests log information,
> they log to a per-test-case log buffer as well as to dmesg.
>
> If the above sounds useful, I'll try and polish up the patch
> for submission. Thanks!
What would be the best way for kunit_tool to:
1. Know that the tests have completed as QEMU will be just sitting
there with kernel complaining about the absence of init (or running
whatever we give it as init)?
2. Read the test results from debugfs under QEMU virtual machine while
the kernel is still there?
I think supplying an init script/binary that copies the
/sys/kernel/debug/kunit/results/* to a 9p shared dir set up by
kunit_tool would work but it would add a step of cross-compiling and
packaging a userspace binary.
Alan Maguire Dec. 6, 2019, 1:53 p.m. UTC | #10
On Wed, 4 Dec 2019, Iurii Zaikin wrote:

> > I've also got a patch that I was hoping to send out soon
> > that might help.  The idea is that each test suite would create
> > a debugfs representation under /sys/kernel/debug/kunit;
> > specifically:
> >
> > /sys/kernel/debug/kunit/results/<suite>
> > /sys/kernel/debug/kunit/results/<suite>-tests
> >
> > ...where cat'ing the former shows the full set of results,
> > and the latter is a directory within which we can display
> > individual test results in test-case-specific files.
> >
> > This is all done by ensuring that when tests log information,
> > they log to a per-test-case log buffer as well as to dmesg.
> >
> > If the above sounds useful, I'll try and polish up the patch
> > for submission. Thanks!
> What would be the best way for kunit_tool to:
> 1. Know that the tests have completed as QEMU will be just sitting
> there with kernel complaining about the absence of init (or running
> whatever we give it as init)?
> 2. Read the test results from debugfs under QEMU virtual machine while
> the kernel is still there?
> I think supplying an init script/binary that copies the
> /sys/kernel/debug/kunit/results/* to a 9p shared dir set up by
> kunit_tool would work but it would add a step of cross-compiling and
> packaging a userspace binary.
> 

I confess I'd only been thinking about supporting the case of a user 
modprobe-ing a kunit test suite module directly and wanting a clean set 
of results separated from other dmesg output. However the scheme you 
describe does seem workable for the UML case also.  With the 
late_initcalls the builtin kunit suites will likely run early in boot but perhaps we could tweak the 
semantics such that the full results debugfs file is not populated until 
the tests have run to simplify script-based probing. I'll try some 
experiments with the debugfs patch once it's ready. Thanks!

Alan

Patch
diff mbox series

diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index ef42ab0..435510f 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -108,7 +108,7 @@  config EXT4_DEBUG
 		echo 1 > /sys/module/ext4/parameters/mballoc_debug
 
 config EXT4_KUNIT_TESTS
-	bool "KUnit tests for ext4"
+	tristate "KUnit tests for ext4"
 	select EXT4_FS
 	depends on KUNIT
 	help
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 840b91d..1e72ef6 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -13,5 +13,10 @@  ext4-y	:= balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \
 
 ext4-$(CONFIG_EXT4_FS_POSIX_ACL)	+= acl.o
 ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o
+ifeq ($(CONFIG_EXT4_KUNIT_TESTS),y)
 ext4-$(CONFIG_EXT4_KUNIT_TESTS)		+= inode-test.o
+else
+obj-$(CONFIG_EXT4_KUNIT_TESTS)		+= ext4-inode-test.o
+ext4-inode-test-objs			+= inode-test.o
+endif
 ext4-$(CONFIG_FS_VERITY)		+= verity.o
diff --git a/fs/ext4/inode-test.c b/fs/ext4/inode-test.c
index 92a9da1..95620bf 100644
--- a/fs/ext4/inode-test.c
+++ b/fs/ext4/inode-test.c
@@ -269,4 +269,6 @@  static void inode_test_xtimestamp_decoding(struct kunit *test)
 	.test_cases = ext4_inode_test_cases,
 };
 
-kunit_test_suite(ext4_inode_test_suite);
+kunit_test_suites(&ext4_inode_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/include/kunit/test.h b/include/kunit/test.h
index dba4830..4e21a36 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -12,6 +12,7 @@ 
 #include <kunit/assert.h>
 #include <kunit/try-catch.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
@@ -197,31 +198,45 @@  struct kunit {
 int kunit_run_tests(struct kunit_suite *suite);
 
 /**
- * kunit_test_suite() - used to register a &struct kunit_suite with KUnit.
+ * kunit_test_suites() - used to register one or more &struct kunit_suite
+ *			 with KUnit.
  *
- * @suite: a statically allocated &struct kunit_suite.
+ * @suites: a statically allocated list of &struct kunit_suite.
  *
- * Registers @suite with the test framework. See &struct kunit_suite for
+ * Registers @suites with the test framework. See &struct kunit_suite for
  * more information.
  *
- * NOTE: Currently KUnit tests are all run as late_initcalls; this means
+ * When builtin,  KUnit tests are all run as late_initcalls; this means
  * that they cannot test anything where tests must run at a different init
  * phase. One significant restriction resulting from this is that KUnit
  * cannot reliably test anything that is initialize in the late_init phase;
  * another is that KUnit is useless to test things that need to be run in
  * an earlier init phase.
  *
+ * An alternative is to build the tests as a module.  Because modules
+ * do not support multiple late_initcall()s, we need to initialize an
+ * array of suites for a module.
+ *
  * TODO(brendanhiggins@google.com): Don't run all KUnit tests as
  * late_initcalls.  I have some future work planned to dispatch all KUnit
  * tests from the same place, and at the very least to do so after
  * everything else is definitely initialized.
  */
-#define kunit_test_suite(suite)						       \
-	static int kunit_suite_init##suite(void)			       \
-	{								       \
-		return kunit_run_tests(&suite);				       \
-	}								       \
-	late_initcall(kunit_suite_init##suite)
+#define kunit_test_suites(...)						\
+	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;						\
+	}								\
+	late_initcall(kunit_test_suites_init);				\
+	static void __exit kunit_test_suites_exit(void)			\
+	{								\
+		return;							\
+	}								\
+	module_exit(kunit_test_suites_exit)
 
 /*
  * Like kunit_alloc_resource() below, but returns the struct kunit_resource
diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
index 2a63241..ccb7850 100644
--- a/kernel/sysctl-test.c
+++ b/kernel/sysctl-test.c
@@ -389,4 +389,6 @@  static void sysctl_test_api_dointvec_write_single_greater_int_max(
 	.test_cases = sysctl_test_cases,
 };
 
-kunit_test_suite(sysctl_test_suite);
+kunit_test_suites(&sysctl_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 6c1be61..4b25bef 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1951,7 +1951,7 @@  config TEST_SYSCTL
 	  If unsure, say N.
 
 config SYSCTL_KUNIT_TEST
-	bool "KUnit test for sysctl"
+	tristate "KUnit test for sysctl"
 	depends on KUNIT
 	help
 	  This builds the proc sysctl unit test, which runs on boot.
@@ -1962,7 +1962,7 @@  config SYSCTL_KUNIT_TEST
 	  If unsure, say N.
 
 config LIST_KUNIT_TEST
-	bool "KUnit Test for Kernel Linked-list structures"
+	tristate "KUnit Test for Kernel Linked-list structures"
 	depends on KUNIT
 	help
 	  This builds the linked list KUnit test suite.
diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
index af37016..9ebd5e6 100644
--- a/lib/kunit/Kconfig
+++ b/lib/kunit/Kconfig
@@ -15,7 +15,7 @@  menuconfig KUNIT
 if KUNIT
 
 config KUNIT_TEST
-	bool "KUnit test for KUnit"
+	tristate "KUnit test for KUnit"
 	help
 	  Enables the unit tests for the KUnit test framework. These tests test
 	  the KUnit test framework itself; the tests are both written using
@@ -24,7 +24,7 @@  config KUNIT_TEST
 	  expected.
 
 config KUNIT_EXAMPLE_TEST
-	bool "Example test for KUnit"
+	tristate "Example test for KUnit"
 	help
 	  Enables an example unit test that illustrates some of the basic
 	  features of KUnit. This test only exists to help new users understand
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index 769d940..bc6e5e54 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -3,7 +3,11 @@  obj-$(CONFIG_KUNIT) +=			test.o \
 					assert.o \
 					try-catch.o
 
-obj-$(CONFIG_KUNIT_TEST) +=		test-test.o \
-					string-stream-test.o
+obj-$(CONFIG_KUNIT_TEST) +=		kunit-test.o
 
-obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	example-test.o
+# string-stream-test compiles built-in only.
+ifeq ($(CONFIG_KUNIT_TEST),y)
+obj-$(CONFIG_KUNIT_TEST) +=		string-stream-test.o
+endif
+
+obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	kunit-example-test.o
diff --git a/lib/kunit/assert.c b/lib/kunit/assert.c
index 9aca71c..b24bebc 100644
--- a/lib/kunit/assert.c
+++ b/lib/kunit/assert.c
@@ -26,6 +26,7 @@  void kunit_base_assert_format(const struct kunit_assert *assert,
 	string_stream_add(stream, "%s FAILED at %s:%d\n",
 			 expect_or_assert, assert->file, assert->line);
 }
+EXPORT_SYMBOL_GPL(kunit_base_assert_format);
 
 void kunit_assert_print_msg(const struct kunit_assert *assert,
 			    struct string_stream *stream)
@@ -33,6 +34,7 @@  void kunit_assert_print_msg(const struct kunit_assert *assert,
 	if (assert->message.fmt)
 		string_stream_add(stream, "\n%pV", &assert->message);
 }
+EXPORT_SYMBOL_GPL(kunit_assert_print_msg);
 
 void kunit_fail_assert_format(const struct kunit_assert *assert,
 			      struct string_stream *stream)
@@ -40,6 +42,7 @@  void kunit_fail_assert_format(const struct kunit_assert *assert,
 	kunit_base_assert_format(assert, stream);
 	string_stream_add(stream, "%pV", &assert->message);
 }
+EXPORT_SYMBOL_GPL(kunit_fail_assert_format);
 
 void kunit_unary_assert_format(const struct kunit_assert *assert,
 			       struct string_stream *stream)
@@ -58,6 +61,7 @@  void kunit_unary_assert_format(const struct kunit_assert *assert,
 				 unary_assert->condition);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_unary_assert_format);
 
 void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
 				     struct string_stream *stream)
@@ -78,6 +82,7 @@  void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
 	}
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_ptr_not_err_assert_format);
 
 void kunit_binary_assert_format(const struct kunit_assert *assert,
 				struct string_stream *stream)
@@ -99,6 +104,7 @@  void kunit_binary_assert_format(const struct kunit_assert *assert,
 			 binary_assert->right_value);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_binary_assert_format);
 
 void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,
 				    struct string_stream *stream)
@@ -120,6 +126,7 @@  void kunit_binary_ptr_assert_format(const struct kunit_assert *assert,
 			 binary_assert->right_value);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_binary_ptr_assert_format);
 
 void kunit_binary_str_assert_format(const struct kunit_assert *assert,
 				    struct string_stream *stream)
@@ -141,3 +148,4 @@  void kunit_binary_str_assert_format(const struct kunit_assert *assert,
 			 binary_assert->right_value);
 	kunit_assert_print_msg(assert, stream);
 }
+EXPORT_SYMBOL_GPL(kunit_binary_str_assert_format);
diff --git a/lib/kunit/example-test.c b/lib/kunit/kunit-example-test.c
similarity index 97%
rename from lib/kunit/example-test.c
rename to lib/kunit/kunit-example-test.c
index f64a829..be1164e 100644
--- a/lib/kunit/example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -85,4 +85,6 @@  static int example_test_init(struct kunit *test)
  * This registers the above test suite telling KUnit that this is a suite of
  * tests that need to be run.
  */
-kunit_test_suite(example_test_suite);
+kunit_test_suites(&example_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/lib/kunit/test-test.c b/lib/kunit/kunit-test.c
similarity index 98%
rename from lib/kunit/test-test.c
rename to lib/kunit/kunit-test.c
index 5a6cc04..ccb8d2e 100644
--- a/lib/kunit/test-test.c
+++ b/lib/kunit/kunit-test.c
@@ -102,7 +102,6 @@  static int kunit_try_catch_test_init(struct kunit *test)
 	.init = kunit_try_catch_test_init,
 	.test_cases = kunit_try_catch_test_cases,
 };
-kunit_test_suite(kunit_try_catch_test_suite);
 
 /*
  * Context for testing test managed resources
@@ -330,4 +329,6 @@  static void kunit_resource_test_exit(struct kunit *test)
 	.exit = kunit_resource_test_exit,
 	.test_cases = kunit_resource_test_cases,
 };
-kunit_test_suite(kunit_resource_test_suite);
+kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite);
+
+MODULE_LICENSE("GPL v2");
diff --git a/lib/kunit/string-stream-test.c b/lib/kunit/string-stream-test.c
index 6c70dc8..110f3a9 100644
--- a/lib/kunit/string-stream-test.c
+++ b/lib/kunit/string-stream-test.c
@@ -50,4 +50,4 @@  static void string_stream_test_get_string(struct kunit *test)
 	.name = "string-stream-test",
 	.test_cases = string_stream_test_cases
 };
-kunit_test_suite(string_stream_test_suite);
+kunit_test_suites(&string_stream_test_suite);
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 58a6227..87b5cf1 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -173,6 +173,7 @@  void kunit_do_assertion(struct kunit *test,
 	if (assert->type == KUNIT_ASSERTION)
 		kunit_abort(test);
 }
+EXPORT_SYMBOL_GPL(kunit_do_assertion);
 
 void kunit_init_test(struct kunit *test, const char *name)
 {
@@ -181,6 +182,7 @@  void kunit_init_test(struct kunit *test, const char *name)
 	test->name = name;
 	test->success = true;
 }
+EXPORT_SYMBOL_GPL(kunit_init_test);
 
 /*
  * Initializes and runs test case. Does not clean up or do post validations.
@@ -319,6 +321,7 @@  int kunit_run_tests(struct kunit_suite *suite)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(kunit_run_tests);
 
 struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
 						    kunit_resource_init_t init,
@@ -344,6 +347,7 @@  struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
 
 	return res;
 }
+EXPORT_SYMBOL_GPL(kunit_alloc_and_get_resource);
 
 static void kunit_resource_free(struct kunit *test, struct kunit_resource *res)
 {
@@ -402,6 +406,7 @@  int kunit_resource_destroy(struct kunit *test,
 	kunit_resource_free(test, resource);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(kunit_resource_destroy);
 
 struct kunit_kmalloc_params {
 	size_t size;
@@ -437,6 +442,7 @@  void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
 				    gfp,
 				    &params);
 }
+EXPORT_SYMBOL_GPL(kunit_kmalloc);
 
 void kunit_kfree(struct kunit *test, const void *ptr)
 {
@@ -449,6 +455,7 @@  void kunit_kfree(struct kunit *test, const void *ptr)
 
 	WARN_ON(rc);
 }
+EXPORT_SYMBOL_GPL(kunit_kfree);
 
 void kunit_cleanup(struct kunit *test)
 {
@@ -478,3 +485,4 @@  void kunit_cleanup(struct kunit *test)
 		kunit_resource_free(test, resource);
 	}
 }
+EXPORT_SYMBOL_GPL(kunit_cleanup);
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
index 4a66d16..0247a28 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);
diff --git a/lib/list-test.c b/lib/list-test.c
index 363c600..76babb1 100644
--- a/lib/list-test.c
+++ b/lib/list-test.c
@@ -743,4 +743,6 @@  static void list_test_list_for_each_entry_reverse(struct kunit *test)
 	.test_cases = list_test_cases,
 };
 
-kunit_test_suite(list_test_module);
+kunit_test_suites(&list_test_module);
+
+MODULE_LICENSE("GPL v2");