drm/tests: Add helper to create mock crtc

We're going to need a full-blown, functional, KMS device to test more
components of the atomic modesetting infrastructure.

Let's add a new helper to create a dumb, mocked, CRTC. By default it
will create a CRTC relying only on the default helpers, but drivers are
free to deviate from that.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-4-8f4af575fce2@kernel.org

drm/tests: Add helper to create mock plane

We're going to need a full-blown, functional, KMS device to test more
components of the atomic modesetting infrastructure.

Let's add a new helper to create a dumb, mocked, primary plane. By
default, it will create a linear XRGB8888 plane, using the default
helpers.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-3-8f4af575fce2@kernel.org

drm/tests: helpers: Include missing drm_drv header

We have a few functions declared in our kunit helpers header, some of
them dereferencing the struct drm_driver.

However, we don't include the drm_drv.h header file defining that
structure, leading to compilation errors if we don't include both
headers.

Fixes: d98780310719 ("drm/tests: helpers: Allow to pass a custom drm_driver")
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-1-8f4af575fce2@kernel.org

drm/tests: helpers: Avoid a driver uaf

when using __drm_kunit_helper_alloc_drm_device() the driver may be
dereferenced by device-managed resources up until the device is
freed, which is typically later than the kunit-managed resource code
frees it. Fix this by simply make the driver device-managed as well.

In short, the sequence leading to the UAF is as follows:

INIT:
Code allocates a struct device as a kunit-managed resource.
Code allocates a drm driver as a kunit-managed resource.
Code allocates a drm device as a device-managed resource.

EXIT:
Kunit resource cleanup frees the drm driver
Kunit resource cleanup puts the struct device, which starts a
device-managed resource cleanup
device-managed cleanup calls drm_dev_put()
drm_dev_put() dereferences the (now freed) drm driver -> Boom.

Related KASAN message:
[55272.551542] ==================================================================
[55272.551551] BUG: KASAN: slab-use-after-free in drm_dev_put.part.0+0xd4/0xe0 [drm]
[55272.551603] Read of size 8 at addr ffff888127502828 by task kunit_try_catch/10353

[55272.551612] CPU: 4 PID: 10353 Comm: kunit_try_catch Tainted: G U N 6.5.0-rc7+ #155
[55272.551620] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 0403 01/26/2021
[55272.551626] Call Trace:
[55272.551629] <TASK>
[55272.551633] dump_stack_lvl+0x57/0x90
[55272.551639] print_report+0xcf/0x630
[55272.551645] ? _raw_spin_lock_irqsave+0x5f/0x70
[55272.551652] ? drm_dev_put.part.0+0xd4/0xe0 [drm]
[55272.551694] kasan_report+0xd7/0x110
[55272.551699] ? drm_dev_put.part.0+0xd4/0xe0 [drm]
[55272.551742] drm_dev_put.part.0+0xd4/0xe0 [drm]
[55272.551783] devres_release_all+0x15d/0x1f0
[55272.551790] ? __pfx_devres_release_all+0x10/0x10
[55272.551797] device_unbind_cleanup+0x16/0x1a0
[55272.551802] device_release_driver_internal+0x3e5/0x540
[55272.551808] ? kobject_put+0x5d/0x4b0
[55272.551814] bus_remove_device+0x1f1/0x3f0
[55272.551819] device_del+0x342/0x910
[55272.551826] ? __pfx_device_del+0x10/0x10
[55272.551830] ? lock_release+0x339/0x5e0
[55272.551836] ? kunit_remove_resource+0x128/0x290 [kunit]
[55272.551845] ? __pfx_lock_release+0x10/0x10
[55272.551851] platform_device_del.part.0+0x1f/0x1e0
[55272.551856] ? _raw_spin_unlock_irqrestore+0x30/0x60
[55272.551863] kunit_remove_resource+0x195/0x290 [kunit]
[55272.551871] ? _raw_spin_unlock_irqrestore+0x30/0x60
[55272.551877] kunit_cleanup+0x78/0x120 [kunit]
[55272.551885] ? __kthread_parkme+0xc1/0x1f0
[55272.551891] ? __pfx_kunit_try_run_case_cleanup+0x10/0x10 [kunit]
[55272.551900] ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10 [kunit]
[55272.551909] kunit_generic_run_threadfn_adapter+0x4a/0x90 [kunit]
[55272.551919] kthread+0x2e7/0x3c0
[55272.551924] ? __pfx_kthread+0x10/0x10
[55272.551929] ret_from_fork+0x2d/0x70
[55272.551935] ? __pfx_kthread+0x10/0x10
[55272.551940] ret_from_fork_asm+0x1b/0x30
[55272.551948] </TASK>

[55272.551953] Allocated by task 10351:
[55272.551956] kasan_save_stack+0x1c/0x40
[55272.551962] kasan_set_track+0x21/0x30
[55272.551966] __kasan_kmalloc+0x8b/0x90
[55272.551970] __kmalloc+0x5e/0x160
[55272.551976] kunit_kmalloc_array+0x1c/0x50 [kunit]
[55272.551984] drm_exec_test_init+0xfa/0x2c0 [drm_exec_test]
[55272.551991] kunit_try_run_case+0xdd/0x250 [kunit]
[55272.551999] kunit_generic_run_threadfn_adapter+0x4a/0x90 [kunit]
[55272.552008] kthread+0x2e7/0x3c0
[55272.552012] ret_from_fork+0x2d/0x70
[55272.552017] ret_from_fork_asm+0x1b/0x30

[55272.552024] Freed by task 10353:
[55272.552027] kasan_save_stack+0x1c/0x40
[55272.552032] kasan_set_track+0x21/0x30
[55272.552036] kasan_save_free_info+0x27/0x40
[55272.552041] __kasan_slab_free+0x106/0x180
[55272.552046] slab_free_freelist_hook+0xb3/0x160
[55272.552051] __kmem_cache_free+0xb2/0x290
[55272.552056] kunit_remove_resource+0x195/0x290 [kunit]
[55272.552064] kunit_cleanup+0x78/0x120 [kunit]
[55272.552072] kunit_generic_run_threadfn_adapter+0x4a/0x90 [kunit]
[55272.552080] kthread+0x2e7/0x3c0
[55272.552085] ret_from_fork+0x2d/0x70
[55272.552089] ret_from_fork_asm+0x1b/0x30

[55272.552096] The buggy address belongs to the object at ffff888127502800
which belongs to the cache kmalloc-512 of size 512
[55272.552105] The buggy address is located 40 bytes inside of
freed 512-byte region [ffff888127502800, ffff888127502a00)

[55272.552115] The buggy address belongs to the physical page:
[55272.552119] page:00000000af6c70ff refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x127500
[55272.552127] head:00000000af6c70ff order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[55272.552133] anon flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
[55272.552141] page_type: 0xffffffff()
[55272.552145] raw: 0017ffffc0010200 ffff888100042c80 0000000000000000 dead000000000001
[55272.552152] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
[55272.552157] page dumped because: kasan: bad access detected

[55272.552163] Memory state around the buggy address:
[55272.552167] ffff888127502700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[55272.552173] ffff888127502780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[55272.552178] >ffff888127502800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[55272.552184] ^
[55272.552187] ffff888127502880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[55272.552193] ffff888127502900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[55272.552198] ==================================================================
[55272.552203] Disabling lock debugging due to kernel taint

v2:
- Update commit message, add Fixes: tag and Cc stable.
v3:
- Further commit message updates (Maxime Ripard).

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # v6.3+
Fixes: d98780310719 ("drm/tests: helpers: Allow to pass a custom drm_driver")
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20230907135339.7971-2-thomas.hellstrom@linux.intel.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

drm/tests: helpers: Create a helper to allocate an atomic state

As we gain more tests, boilerplate to allocate an atomic state and free
it starts to be there more and more as well.

In order to reduce the allocation boilerplate, we can create a helper
to create that atomic state, and call an action when the test is done.
This will also clean up the exit path.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maíra Canal <mairacanal@riseup.net>
Link: https://lore.kernel.org/r/20230728-kms-kunit-actions-rework-v3-6-952565ccccfe@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>

drm/tests: helpers: Create a helper to allocate a locking ctx

As we get more and more tests, the locking context initialisation
creates more and more boilerplate, both at creation and destruction.

Let's create a helper that will allocate, initialise a context, and
register kunit actions to clean up once the test is done.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maíra Canal <mairacanal@riseup.net>
Link: https://lore.kernel.org/r/20230728-kms-kunit-actions-rework-v3-5-952565ccccfe@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>

drm/tests: helpers: Allow to pass a custom drm_driver

Some tests will need to provide their own drm_driver instead of relying
on the dumb one in the helpers, so let's create a helper that allows to
do so.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-11-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/tests: helpers: Allow for a custom device struct to be allocated

The current helper to allocate a DRM device doesn't allow for any
subclassing by drivers, which is going to be troublesome as we work on
getting some kunit testing on atomic modesetting code.

Let's use a similar pattern to the other allocation helpers by providing
the structure size and offset as arguments.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-10-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/tests: helpers: Create the device in another function

We'll need in some tests to control when the device needs to be added
and removed, so let's split the device creation from the DRM device
creation function.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-7-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/tests: helpers: Remove the name parameter

The device name isn't really useful, we can just define it instead of
exposing it in the API.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-6-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/tests: helpers: Rename the device init helper

The name doesn't really fit the conventions for the other helpers in
DRM/KMS, so let's rename it to make it obvious that we allocate a new
DRM device.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-5-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drm/tests: helpers: Move the helper header to include/drm

We'll need to use those helpers from drivers too, so let's move it to a
more visible location.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-1-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>