linux.git/lib/kunit/test.c, branch v6.12.80

kunit: Device wrappers should also manage driver name

2024-08-26T13:03:46+00:00

kunit_driver_create() accepts a name for the driver, but does not copy
it, so if that name is either on the stack, or otherwise freed, we end
up with a use-after-free when the driver is cleaned up.

Instead, strdup() the name, and manage it as another KUnit allocation.
As there was no existing kunit_kstrdup(), we add one. Further, add a
kunit_ variant of strdup_const() and kfree_const(), so we don't need to
allocate and manage the string in the majority of cases where it's a
constant.

However, these are inline functions, and is_kernel_rodata() only works
for built-in code. This causes problems in two cases:
- If kunit is built as a module, __{start,end}_rodata is not defined.
- If a kunit test using these functions is built as a module, it will
  suffer the same fate.

This fixes a KASAN splat with overflow.overflow_allocation_test, when
built as a module.

Restrict the is_kernel_rodata() case to when KUnit is built as a module,
which fixes the first case, at the cost of losing the optimisation.

Also, make kunit_{kstrdup,kfree}_const non-inline, so that other modules
using them will not accidentally depend on is_kernel_rodata(). If KUnit
is built-in, they'll benefit from the optimisation, if KUnit is not,
they won't, but the string will be properly duplicated.

Fixes: d03c720e03bd ("kunit: Add APIs for managing devices")
Reported-by: Nico Pache 
Closes: https://groups.google.com/g/kunit-dev/c/81V9b9QYON0
Reviewed-by: Kees Cook 
Reviewed-by: Maxime Ripard 
Reviewed-by: Rae Moar 
Signed-off-by: David Gow 
Tested-by: Rae Moar 
Signed-off-by: Shuah Khan

kunit: add missing MODULE_DESCRIPTION() macros to core modules

2024-06-07T21:59:05+00:00

make allmodconfig && make W=1 C=1 reports in lib/kunit:
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit-test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/kunit/kunit-example-test.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

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

kunit: bail out early in __kunit_test_suites_init() if there are no suites to test

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

Commit c72a870926c2 added a mutex to prevent kunit tests from running
concurrently.  Unfortunately that mutex gets locked during module load
regardless of whether the module actually has any kunit tests.  This
causes a problem for kunit tests that might need to load other kernel
modules (e.g. gss_krb5_test loading the camellia module).

So check to see if there are actually any tests to run before locking
the kunit_run_lock mutex.

Fixes: c72a870926c2 ("kunit: add ability to run tests after boot using debugfs")
Reported-by: Nico Pache 
Signed-off-by: Scott Mayhew 
Reviewed-by: Rae Moar 
Reviewed-by: David Gow 
Signed-off-by: Shuah Khan

kunit: device: Unregister the kunit_bus on shutdown

2024-02-07T00:07:37+00:00

If KUnit is built as a module, and it's unloaded, the kunit_bus is not
unregistered. This causes an error if it's then re-loaded later, as we
try to re-register the bus.

Unregister the bus and root_device on shutdown, if it looks valid.

In addition, be more specific about the value of kunit_bus_device. It
is:
- a valid struct device* if the kunit_bus initialised correctly.
- an ERR_PTR if it failed to initialise.
- NULL before initialisation and after shutdown.

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

kunit: run test suites only after module initialization completes

2024-01-22T14:58:54+00:00

Commit 2810c1e99867 ("kunit: Fix wild-memory-access bug in
kunit_free_suite_set()") fixed a wild-memory-access bug that could have
happened during the loading phase of test suites built and executed as
loadable modules. However, it also introduced a problematic side effect
that causes test suites modules to crash when they attempt to register
fake devices.

When a module is loaded, it traverses the MODULE_STATE_UNFORMED and
MODULE_STATE_COMING states before reaching the normal operating state
MODULE_STATE_LIVE. Finally, when the module is removed, it moves to
MODULE_STATE_GOING before being released. However, if the loading
function load_module() fails between complete_formation() and
do_init_module(), the module goes directly from MODULE_STATE_COMING to
MODULE_STATE_GOING without passing through MODULE_STATE_LIVE.

This behavior was causing kunit_module_exit() to be called without
having first executed kunit_module_init(). Since kunit_module_exit() is
responsible for freeing the memory allocated by kunit_module_init()
through kunit_filter_suites(), this behavior was resulting in a
wild-memory-access bug.

Commit 2810c1e99867 ("kunit: Fix wild-memory-access bug in
kunit_free_suite_set()") fixed this issue by running the tests when the
module is still in MODULE_STATE_COMING. However, modules in that state
are not fully initialized, lacking sysfs kobjects. Therefore, if a test
module attempts to register a fake device, it will inevitably crash.

This patch proposes a different approach to fix the original
wild-memory-access bug while restoring the normal module execution flow
by making kunit_module_exit() able to detect if kunit_module_init() has
previously initialized the tests suite set. In this way, test modules
can once again register fake devices without crashing.

This behavior is achieved by checking whether mod->kunit_suites is a
virtual or direct mapping address. If it is a virtual address, then
kunit_module_init() has allocated the suite_set in kunit_filter_suites()
using kmalloc_array(). On the contrary, if mod->kunit_suites is still
pointing to the original address that was set when looking up the
.kunit_test_suites section of the module, then the loading phase has
failed and there's no memory to be freed.

v4:
- rebased on 6.8
- noted that kunit_filter_suites() must return a virtual address
v3:
- add a comment to clarify why the start address is checked
v2:
- add include 

Fixes: 2810c1e99867 ("kunit: Fix wild-memory-access bug in kunit_free_suite_set()")
Reviewed-by: David Gow 
Tested-by: Rae Moar 
Tested-by: Richard Fitzgerald 
Reviewed-by: Javier Martinez Canillas 
Signed-off-by: Marco Pagani 
Signed-off-by: Shuah Khan

kunit: Fix NULL-dereference in kunit_init_suite() if suite->log is NULL

2024-01-03T16:06:19+00:00

suite->log must be checked for NULL before passing it to
string_stream_clear(). This was done in kunit_init_test() but was missing
from kunit_init_suite().

Signed-off-by: Richard Fitzgerald 
Fixes: 6d696c4695c5 ("kunit: add ability to run tests after boot using debugfs")
Reviewed-by: Rae Moar 
Acked-by: David Gow 
Reviewed-by: Muhammad Usama Anjum 
Signed-off-by: Shuah Khan

kunit: Reset test->priv after each param iteration

2023-12-18T20:39:05+00:00

If we run parameterized test that uses test->priv to prepare some
custom data, then value of test->priv will leak to the next param
iteration and may be unexpected.  This could be easily seen if
we promote example_priv_test to parameterized test as then only
first test iteration will be successful:

$ ./tools/testing/kunit/kunit.py run \
	--kunitconfig ./lib/kunit/.kunitconfig *.example_priv*

[ ] Starting KUnit Kernel (1/1)...
[ ] ============================================================
[ ] =================== example (1 subtest) ====================
[ ] ==================== example_priv_test  ====================
[ ] [PASSED] example value 3
[ ] # example_priv_test: initializing
[ ] # example_priv_test: ASSERTION FAILED at lib/kunit/kunit-example-test.c:230
[ ] Expected test->priv == ((void *)0), but
[ ]     test->priv == 0000000060dfe290
[ ]     ((void *)0) == 0000000000000000
[ ] # example_priv_test: cleaning up
[ ] [FAILED] example value 2
[ ] # example_priv_test: initializing
[ ] # example_priv_test: ASSERTION FAILED at lib/kunit/kunit-example-test.c:230
[ ] Expected test->priv == ((void *)0), but
[ ]     test->priv == 0000000060dfe290
[ ]     ((void *)0) == 0000000000000000
[ ] # example_priv_test: cleaning up
[ ] [FAILED] example value 1
[ ] # example_priv_test: initializing
[ ] # example_priv_test: ASSERTION FAILED at lib/kunit/kunit-example-test.c:230
[ ] Expected test->priv == ((void *)0), but
[ ]     test->priv == 0000000060dfe290
[ ]     ((void *)0) == 0000000000000000
[ ] # example_priv_test: cleaning up
[ ] [FAILED] example value 0
[ ] # example_priv_test: initializing
[ ] # example_priv_test: cleaning up
[ ] # example_priv_test: pass:1 fail:3 skip:0 total:4
[ ] ================ [FAILED] example_priv_test ================
[ ]     # example: initializing suite
[ ]     # module: kunit_example_test
[ ]     # example: exiting suite
[ ] # Totals: pass:1 fail:3 skip:0 total:4
[ ] ===================== [FAILED] example =====================

Fix that by resetting test->priv after each param iteration, in
similar way what we did for the test->status.

Signed-off-by: Michal Wajdeczko 
Cc: David Gow 
Cc: 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 ability to run tests after boot using debugfs

2023-12-18T20:25:49+00:00

Add functionality to run built-in tests after boot by writing to a
debugfs file.

Add a new debugfs file labeled "run" for each test suite to use for
this purpose.

As an example, write to the file using the following:

echo "any string" > /sys/kernel/debugfs/kunit//run

This will trigger the test suite to run and will print results to the
kernel log.

To guard against running tests concurrently with this feature, add a
mutex lock around running kunit. This supports the current practice of
not allowing tests to be run concurrently on the same kernel.

This new functionality could be used to design a parameter
injection feature in the future.

Fixed up merge conflict duing rebase to Linux 6.7-rc6
Signed-off-by: Shuah Khan 

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

kunit: add KUNIT_INIT_TABLE to init linker section

2023-12-18T20:21:15+00:00

Add KUNIT_INIT_TABLE to the INIT_DATA linker section.

Alter the KUnit macros to create init tests:
kunit_test_init_section_suites

Update lib/kunit/executor.c to run both the suites in KUNIT_TABLE and
KUNIT_INIT_TABLE.

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