kunit: string-stream-test: Avoid cast warning when testing gfp_t flags

Passing a gfp_t to KUNIT_EXPECT_EQ() causes a cast warning:

lib/kunit/string-stream-test.c:73:9: sparse: sparse: incorrect type in
initializer (different base types) expected long long right_value
got restricted gfp_t const __right

Avoid this by testing stream->gfp for the expected value and passing the
boolean result of this comparison to KUNIT_EXPECT_TRUE(), as was already
done a few lines above in string_stream_managed_init_test().

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: d1a0d699bfc0 ("kunit: string-stream: Add tests for freeing resource-managed string_stream")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311181918.0mpCu2Xh-lkp@intel.com/
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: string-stream: Test performance of string_stream

Add a test of the speed and memory use of string_stream.

string_stream_performance_test() doesn't actually "test" anything (it
cannot fail unless the system has run out of allocatable memory) but it
measures the speed and memory consumption of the string_stream and reports
the result.

This allows changes in the string_stream implementation to be compared.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: string-stream: Add tests for freeing resource-managed string_stream

string_stream_managed_free_test() allocates a resource-managed
string_stream and tests that kunit_free_string_stream() calls
string_stream_destroy().

string_stream_resource_free_test() allocates a resource-managed
string_stream and tests that string_stream_destroy() is called
when the test resources are cleaned up.

The old string_stream_init_test() has been split into two tests,
one for kunit_alloc_string_stream() and the other for
alloc_string_stream().

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: string-stream: Decouple string_stream from kunit

Re-work string_stream so that it is not tied to a struct kunit. This is
to allow using it for the log of struct kunit_suite.

Instead of resource-managing individual allocations the whole string_stream
can be resource-managed, if required.

alloc_string_stream() now allocates a string stream that is
not resource-managed.

string_stream_destroy() now works on an unmanaged string_stream
allocated by alloc_string_stream() and frees the entire
string_stream (previously it only freed the fragments).

string_stream_clear() has been made public for callers that
want to free the fragments without destroying the string_stream.

For resource-managed allocations use kunit_alloc_string_stream()
and kunit_free_string_stream().

In addition to this, string_stream_get_string() now returns an
unmanaged buffer that the caller must kfree().

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: string-stream: Add kunit_alloc_string_stream()

Add function kunit_alloc_string_stream() to do a resource-managed
allocation of a string stream, and corresponding
kunit_free_string_stream() to free the resource-managed stream.

This is preparing for decoupling the string_stream
implementation from struct kunit, to reduce the amount of code
churn when that happens. Currently:
- kunit_alloc_string_stream() only calls alloc_string_stream().
- kunit_free_string_stream() takes a struct kunit* which
isn't used yet.

Callers of the old alloc_string_stream() and
string_stream_destroy() are all requesting a managed allocation
so have been changed to use the new functions.

alloc_string_stream() has been temporarily made static because
its current behavior has been replaced with
kunit_alloc_string_stream().

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: string-stream-test: Add cases for string_stream newline appending

Add test cases for testing the string_stream feature that appends a
newline to strings that do not already end with a newline.

string_stream_no_auto_newline_test() tests with this feature disabled.
Newlines should not be added or dropped.

string_stream_auto_newline_test() tests with this feature enabled.
Newlines should be added to lines that do not end with a newline.

string_stream_append_auto_newline_test() tests appending the
content of one stream to another stream when the target stream
has newline appending enabled.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: string-stream: Improve testing of string_stream

Replace the minimal tests with more-thorough testing.

string_stream_init_test() tests that struct string_stream is
initialized correctly.

string_stream_line_add_test() adds a series of numbered lines and
checks that the resulting string contains all the lines.

string_stream_variable_length_line_test() adds a large number of
lines of varying length to create many fragments, then tests that all
lines are present.

string_stream_append_test() tests various cases of using
string_stream_append() to append the content of one stream to another.

Adds string_stream_append_empty_string_test() to test that adding an
empty string to a string_stream doesn't create a new empty fragment.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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>

kunit: move string-stream.h to lib/kunit

string-stream interfaces are not intended for external use;
move them from include/kunit to lib/kunit accordingly.

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>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: test: add the concept of assertions

Add support for assertions which are like expectations except the test
terminates if the assertion is not satisfied.

The idea with assertions is that you use them to state all the
preconditions for your test. Logically speaking, these are the premises
of the test case, so if a premise isn't true, there is no point in
continuing the test case because there are no conclusions that can be
drawn without the premises. Whereas, the expectation is the thing you
are trying to prove. It is not used universally in x-unit style test
frameworks, but I really like it as a convention. You could still
express the idea of a premise using the above idiom, but I think
KUNIT_ASSERT_* states the intended idea perfectly.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: test: add initial tests

Add a test for string stream along with a simpler example.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>