linux.git/lib/kunit/kunit-test.c, branch arm64-uaccess

kunit: test: Move fault tests behind KUNIT_FAULT_TEST Kconfig option

2024-05-06T20:22:02+00:00

The NULL dereference tests in kunit_fault deliberately trigger a kernel
BUG(), and therefore print the associated stack trace, even when the
test passes. This is both annoying (as it bloats the test output), and
can confuse some test harnesses, which assume any BUG() is a failure.

Allow these tests to be specifically disabled (without disabling all
of KUnit's other tests), by placing them behind the
CONFIG_KUNIT_FAULT_TEST Kconfig option. This is enabled by default, but
can be set to 'n' to disable the test. An empty 'kunit_fault' suite is
left behind, which will automatically be marked 'skipped'.

As the fault tests already were disabled under UML (as they weren't
compatible with its fault handling), we can simply adapt those
conditions, and add a dependency on !UML for our new option.

Suggested-by: Guenter Roeck 
Link: https://lore.kernel.org/all/928249cc-e027-4f7f-b43f-502f99a1ea63@roeck-us.net/
Fixes: 82b0beff3497 ("kunit: Add tests for fault")
Signed-off-by: David Gow 
Reviewed-by: Mickaël Salaün 
Reviewed-by: Rae Moar 
Signed-off-by: Shuah Khan

kunit: Add tests for fault

2024-05-06T20:22:02+00:00

Add a test case to check NULL pointer dereference and make sure it would
result as a failed test.

The full kunit_fault test suite is marked as skipped when run on UML
because it would result to a kernel panic.

Tested with:
./tools/testing/kunit/kunit.py run --arch x86_64 kunit_fault
./tools/testing/kunit/kunit.py run --arch arm64 \
  --cross_compile=aarch64-linux-gnu- kunit_fault

Cc: Brendan Higgins 
Cc: Rae Moar 
Cc: Shuah Khan 
Reviewed-by: David Gow 
Signed-off-by: Mickaël Salaün 
Link: https://lore.kernel.org/r/20240408074625.65017-8-mic@digikod.net
Signed-off-by: Shuah Khan

kunit: Fix a NULL vs IS_ERR() bug

2024-01-22T14:58:12+00:00

The kunit_device_register() function doesn't return NULL, it returns
error pointers.  Change the KUNIT_ASSERT_NOT_NULL() to check for
ERR_OR_NULL().

Fixes: d03c720e03bd ("kunit: Add APIs for managing devices")
Signed-off-by: Dan Carpenter 
Reviewed-by: Rae Moar 
Reviewed-by: David Gow 
Signed-off-by: Shuah Khan

kunit: Add APIs for managing devices

2023-12-18T20:28:08+00:00

Tests for drivers often require a struct device to pass to other
functions. While it's possible to create these with
root_device_register(), or to use something like a platform device, this
is both a misuse of those APIs, and can be difficult to clean up after,
for example, a failed assertion.

Add some KUnit-specific functions for registering and unregistering a
struct device:
- kunit_device_register()
- kunit_device_register_with_driver()
- kunit_device_unregister()

These helpers allocate a on a 'kunit' bus which will either probe the
driver passed in (kunit_device_register_with_driver), or will create a
stub driver (kunit_device_register) which is cleaned up on test shutdown.

Devices are automatically unregistered on test shutdown, but can be
manually unregistered earlier with kunit_device_unregister() in order
to, for example, test device release code.

Reviewed-by: Matti Vaittinen 
Reviewed-by: Maxime Ripard 
Signed-off-by: David Gow 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Shuah Khan

kunit: Add a macro to wrap a deferred action function

2023-12-18T20:21:14+00:00

KUnit's deferred action API accepts a void(*)(void *) function pointer
which is called when the test is exited. However, we very frequently
want to use existing functions which accept a single pointer, but which
may not be of type void*. While this is probably dodgy enough to be on
the wrong side of the C standard, it's been often used for similar
callbacks, and gcc's -Wcast-function-type seems to ignore cases where
the only difference is the type of the argument, assuming it's
compatible (i.e., they're both pointers to data).

However, clang 16 has introduced -Wcast-function-type-strict, which no
longer permits any deviation in function pointer type. This seems to be
because it'd break CFI, which validates the type of function calls.

This rather ruins our attempts to cast functions to defer them, and
leaves us with a few options. The one we've chosen is to implement a
macro which will generate a wrapper function which accepts a void*, and
casts the argument to the appropriate type.

For example, if you were trying to wrap:
void foo_close(struct foo *handle);
you could use:
KUNIT_DEFINE_ACTION_WRAPPER(kunit_action_foo_close,
			    foo_close,
			    struct foo *);

This would create a new kunit_action_foo_close() function, of type
kunit_action_t, which could be passed into kunit_add_action() and
similar functions.

In addition to defining this macro, update KUnit and its tests to use
it.

Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Reviewed-by: Nathan Chancellor 
Tested-by: Nathan Chancellor 
Acked-by: Daniel Vetter 
Reviewed-by: Maxime Ripard 
Signed-off-by: David Gow 
Signed-off-by: Shuah Khan

kunit: test: Avoid cast warning when adding kfree() as an action

2023-11-14T20:01:57+00:00

In kunit_log_test() pass the kfree_wrapper() function to kunit_add_action()
instead of directly passing kfree().

This prevents a cast warning:

lib/kunit/kunit-test.c:565:25: warning: cast from 'void (*)(const void *)'
to 'kunit_action_t *' (aka 'void (*)(void *)') converts to incompatible
function type [-Wcast-function-type-strict]

   564		full_log = string_stream_get_string(test->log);
 > 565		kunit_add_action(test, (kunit_action_t *)kfree, full_log);

Signed-off-by: Richard Fitzgerald 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202311070041.kWVYx7YP-lkp@intel.com/
Fixes: 05e2006ce493 ("kunit: Use string_stream for test log")
Reviewed-by: David Gow 
Signed-off-by: Shuah Khan

kunit: Use string_stream for test log

2023-09-18T16:45:53+00:00

Replace the fixed-size log buffer with a string_stream so that the
log can grow as lines are added.

The existing kunit log tests have been updated for using a
string_stream as the log. No new test have been added because there
are already tests for the underlying string_stream.

As the log tests now depend on string_stream functions they cannot
build when kunit-test is a module. They have been surrounded by
a #if to replace them with skipping version when the test is
build as a module. Though this isn't pretty, it avoids moving
code to another file while that code is also being changed.

Signed-off-by: Richard Fitzgerald 
Reviewed-by: David Gow 
Signed-off-by: Shuah Khan

kunit: Add kunit_add_action() to defer a call until test exit

2023-05-25T14:52:55+00:00

Many uses of the KUnit resource system are intended to simply defer
calling a function until the test exits (be it due to success or
failure). The existing kunit_alloc_resource() function is often used for
this, but was awkward to use (requiring passing NULL init functions, etc),
and returned a resource without incrementing its reference count, which
-- while okay for this use-case -- could cause problems in others.

Instead, introduce a simple kunit_add_action() API: a simple function
(returning nothing, accepting a single void* argument) can be scheduled
to be called when the test exits. Deferred actions are called in the
opposite order to that which they were registered.

This mimics the devres API, devm_add_action(), and also provides
kunit_remove_action(), to cancel a deferred action, and
kunit_release_action() to trigger one early.

This is implemented as a resource under the hood, so the ordering
between resource cleanup and deferred functions is maintained.

Reviewed-by: Benjamin Berg 
Reviewed-by: Maxime Ripard 
Tested-by: Maxime Ripard 
Signed-off-by: David Gow 
Signed-off-by: Shuah Khan

kunit: add tests for using current KUnit test field

2023-04-05T18:51:30+00:00

Create test suite called "kunit_current" to add test coverage for the use
of current->kunit_test, which returns the current KUnit test.

Add two test cases:
- kunit_current_test to test current->kunit_test and the method
  kunit_get_current_test(), which utilizes current->kunit_test.

- kunit_current_fail_test to test the method
  kunit_fail_current_test(), which utilizes current->kunit_test.

Signed-off-by: Rae Moar 
Reviewed-by: Daniel Latypov 
Reviewed-by: David Gow 
Signed-off-by: Shuah Khan

kunit: fix bug of extra newline characters in debugfs logs

2023-03-10T20:59:43+00:00

Fix bug of the extra newline characters in debugfs logs. When a
line is added to debugfs with a newline character at the end,
an extra line appears in the debugfs log.

This is due to a discrepancy between how the lines are printed and how they
are added to the logs. Remove this discrepancy by checking if a newline
character is present before adding a newline character. This should closely
match the printk behavior.

Add kunit_log_newline_test to provide test coverage for this issue.  (Also,
move kunit_log_test above suite definition to remove the unnecessary
declaration prior to the suite definition)

As an example, say we add these two lines to the log:

kunit_log(..., "KTAP version 1\n");
kunit_log(..., "1..1");

The debugfs log before this fix:

 KTAP version 1

 1..1

The debugfs log after this fix:

 KTAP version 1
 1..1

Signed-off-by: Rae Moar 
Reviewed-by: David Gow 
Signed-off-by: Shuah Khan