[ Upstream commit c73b4db076faf827d0656665ef5e97b76926b60f ]

Properly initialize input_device_id structure in
input_test_match_device_id test to make sure it contains no garbage
causing the test to randomly fail.

Fixes: fdefcbdd6f36 ("Input: Add KUnit tests for some of the input core helper functions")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/ZFLI7T2qZTGJ1UUK@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit fd75f3694b1dd5070408ea4a58ca7f8e0a3fcbcd ]

With CONFIG_DEBUG_SLAB=y:

        # Subtest: input_core
        1..3
    input: Test input device as /devices/virtual/input/input1
    8<--- cut here ---
    Unable to handle kernel paging request at virtual address 6b6b6dd7 when read
    ...
     __lock_acquire from lock_acquire+0x26c/0x300
     lock_acquire from _raw_spin_lock_irqsave+0x50/0x64
     _raw_spin_lock_irqsave from devres_remove+0x20/0x7c
     devres_remove from devres_destroy+0x8/0x24
     devres_destroy from input_free_device+0x2c/0x60
     input_free_device from kunit_try_run_case+0x70/0x94 [kunit]

Without CONFIG_DEBUG_SLAB=y:

	KTAP version 1
	# Subtest: input_core
	1..3
    input: Test input device as /devices/virtual/input/input1
    ------------[ cut here ]------------
    WARNING: CPU: 0 PID: 694 at lib/refcount.c:28 refcount_warn_saturate+0x54/0x100
    refcount_t: underflow; use-after-free.
    ...
    Call Trace: [<0037cad4>] dump_stack+0xc/0x10
     [<00377614>] __warn+0x7e/0xb4
     [<0037768c>] warn_slowpath_fmt+0x42/0x62
     [<001eee1c>] refcount_warn_saturate+0x54/0x100
     [<000b1d34>] kfree_const+0x0/0x20
     [<0036290a>] __kobject_del+0x0/0x6e
     [<001eee1c>] refcount_warn_saturate+0x54/0x100
     [<00362a1a>] kobject_put+0xa2/0xb6
     [<11965770>] kunit_generic_run_threadfn_adapter+0x0/0x1c [kunit]

As per the comments for input_allocate_device() and
input_register_device(), input_free_device() must be called only to free
devices that have not been registered.  input_unregister_device()
already calls input_put_device(), thus leading to a use-after-free.

Moreover, the kunit_suite.exit() method is called after every test case,
even on failures.  As the test itself already does cleanups in its
failure paths, this may lead to a second use-after-free.

Fix the first issue by dropping the call to input_allocate_device() from
input_test_exit().
Fix the second issue by making the cleanup code conditional on a
successful test.

Fixes: fdefcbdd6f361841 ("Input: Add KUnit tests for some of the input core helper functions")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/957b3b309a44d39fb6e38b2a526b250f69ea3d2c.1683022164.git.geert+renesas@glider.be
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

The input subsystem doesn't currently have any unit tests, let's add a
CONFIG_INPUT_KUNIT_TEST option that builds a test suite to be executed
with the KUnit test infrastructure.

For now, only three tests were added for some of the input core helper
functions that are trivial to test:

  * input_test_polling: set/get poll interval and set-up a poll handler.

  * input_test_timestamp: set/get input event timestamps.

  * input_test_match_device_id: match a device by bus, vendor, product,
                                version and events capable of handling.

But having the minimal KUnit support allows to add more tests and suites
as follow-up changes. The tests can be run with the following command:

  $ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/input/tests/

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Enric Balletbo i Serra <eballetbo@redhat.com>
config: powerpc-allnoconfig (https://download.01.org/0day-ci/archive/20230330/202303301815.kRKFM3NH-lkp@intel.com/config)
Link: https://lore.kernel.org/r/20230330081831.2291351-1-javierm@redhat.com

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>