mbox series

[v7,0/7] DRM scheduler kunit tests

Message ID 20250311092339.52199-1-tvrtko.ursulin@igalia.com (mailing list archive)
Headers show
Series DRM scheduler kunit tests | expand

Message

Tvrtko Ursulin March 11, 2025, 9:23 a.m. UTC
There has repeatedly been quite a bit of apprehension when any change to the DRM
scheduler is proposed, with two main reasons being code base is considered
fragile, not well understood and not very well documented, and secondly the lack
of systematic testing outside the vendor specific tests suites and/or test
farms.

This series is an attempt to dislodge this status quo by adding some unit tests
using the kunit framework.

General approach is that there is a mock "hardware" backend which can be
controlled from tests, which in turn allows exercising various scheduler code
paths.

Only some simple basic tests get added in the series and hopefully it is easy to
understand what tests are doing.

An obligatory "screenshot" for reference:

[14:09:05] ============ drm_sched_basic_tests (3 subtests) ============
[14:09:06] [PASSED] drm_sched_basic_submit
[14:09:06] ================== drm_sched_basic_test  ===================
[14:09:06] [PASSED] A queue of jobs in a single entity
[14:09:06] [PASSED] A chain of dependent jobs across multiple entities
[14:09:06] [PASSED] Multiple independent job queues
[14:09:06] [PASSED] Multiple inter-dependent job queues
[14:09:07] ============== [PASSED] drm_sched_basic_test ===============
[14:09:07] [PASSED] drm_sched_basic_entity_cleanup
[14:09:07] ============== [PASSED] drm_sched_basic_tests ==============
[14:09:07] ======== drm_sched_basic_timeout_tests (1 subtest) =========
[14:09:08] [PASSED] drm_sched_basic_timeout
[14:09:08] ========== [PASSED] drm_sched_basic_timeout_tests ==========
[14:09:08] ======= drm_sched_basic_priority_tests (2 subtests) ========
[14:09:10] [PASSED] drm_sched_priorities
[14:09:10] [PASSED] drm_sched_change_priority
[14:09:10] ========= [PASSED] drm_sched_basic_priority_tests ==========
[14:09:10] ====== drm_sched_basic_modify_sched_tests (1 subtest) ======
[14:09:11] [PASSED] drm_sched_test_modify_sched
[14:09:11] ======= [PASSED] drm_sched_basic_modify_sched_tests ========
[14:09:11] ======== drm_sched_basic_credits_tests (1 subtest) =========
[14:09:12] [PASSED] drm_sched_test_credits
[14:09:12] ========== [PASSED] drm_sched_basic_credits_tests ==========
[14:09:12] ============================================================
[14:09:12] Testing complete. Ran 11 tests: passed: 11
[14:09:13] Elapsed time: 13.539s total, 0.001s configuring, 3.004s building, 10.462s running

v2:
 * Parameterize a bunch of similar tests.
 * Improve test commentary.
 * Rename TDR test to timeout. (Christian)
 * Improve quality and consistency of naming. (Philipp)

RFC v2 -> series v1:
 * Rebased for drm_sched_init changes.
 * Fixed modular build.
 * Added some comments.
 * Filename renames. (Philipp)

v2:
 * Dealt with a bunch of checkpatch warnings.

v3:
 * Some mock API renames, kerneldoc grammar fixes and indentation fixes.

v4:
 * Fix use after free caused by relying on scheduler fence for querying status.
 * Kerneldoc fixes.

v5:
 * Cleanup in-flight jobs on scheduler shutdown.
 * Change hang_limit to 1.

v6:
 * Use KUNIT_ASSERT_TRUE/FALSE.
 * Fixed patch titles.
 * Added credit_limit test.
 * Added CONFIG_DRM_SCHED_KUNIT_TEST_ASPIRATIONAL.

v7:
 * v6 omitted to send the first patch by mistake.

Cc: Christian König <christian.koenig@amd.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <phasta@kernel.org>

Tvrtko Ursulin (7):
  drm: Move some options to separate new Kconfig
  drm/sched: Add scheduler unit testing infrastructure and some basic
    tests
  drm/sched: Add aspirational unit test mode
  drm/sched: Add a simple timeout test
  drm/sched: Add basic priority tests
  drm/sched: Add a basic test for modifying entities scheduler list
  drm/sched: Add a basic test for checking credit limit

 drivers/gpu/drm/Kconfig                       | 109 +---
 drivers/gpu/drm/Kconfig.debug                 | 128 +++++
 drivers/gpu/drm/scheduler/.kunitconfig        |  12 +
 drivers/gpu/drm/scheduler/Makefile            |   2 +
 drivers/gpu/drm/scheduler/tests/Makefile      |   7 +
 .../gpu/drm/scheduler/tests/mock_scheduler.c  | 345 +++++++++++++
 drivers/gpu/drm/scheduler/tests/sched_tests.h | 224 +++++++++
 drivers/gpu/drm/scheduler/tests/tests_basic.c | 476 ++++++++++++++++++
 8 files changed, 1199 insertions(+), 104 deletions(-)
 create mode 100644 drivers/gpu/drm/Kconfig.debug
 create mode 100644 drivers/gpu/drm/scheduler/.kunitconfig
 create mode 100644 drivers/gpu/drm/scheduler/tests/Makefile
 create mode 100644 drivers/gpu/drm/scheduler/tests/mock_scheduler.c
 create mode 100644 drivers/gpu/drm/scheduler/tests/sched_tests.h
 create mode 100644 drivers/gpu/drm/scheduler/tests/tests_basic.c

Comments

Philipp Stanner March 12, 2025, 10:39 a.m. UTC | #1
On Tue, 2025-03-11 at 09:23 +0000, Tvrtko Ursulin wrote:
> There has repeatedly been quite a bit of apprehension when any change
> to the DRM
> scheduler is proposed, with two main reasons being code base is
> considered
> fragile, not well understood and not very well documented, and
> secondly the lack
> of systematic testing outside the vendor specific tests suites and/or
> test
> farms.
> 
> This series is an attempt to dislodge this status quo by adding some
> unit tests
> using the kunit framework.
> 
> General approach is that there is a mock "hardware" backend which can
> be
> controlled from tests, which in turn allows exercising various
> scheduler code
> paths.
> 
> Only some simple basic tests get added in the series and hopefully it
> is easy to
> understand what tests are doing.
> 
> An obligatory "screenshot" for reference:
> 
> [14:09:05] ============ drm_sched_basic_tests (3 subtests)
> ============
> [14:09:06] [PASSED] drm_sched_basic_submit
> [14:09:06] ================== drm_sched_basic_test 
> ===================
> [14:09:06] [PASSED] A queue of jobs in a single entity
> [14:09:06] [PASSED] A chain of dependent jobs across multiple
> entities
> [14:09:06] [PASSED] Multiple independent job queues
> [14:09:06] [PASSED] Multiple inter-dependent job queues
> [14:09:07] ============== [PASSED] drm_sched_basic_test
> ===============
> [14:09:07] [PASSED] drm_sched_basic_entity_cleanup
> [14:09:07] ============== [PASSED] drm_sched_basic_tests
> ==============
> [14:09:07] ======== drm_sched_basic_timeout_tests (1 subtest)
> =========
> [14:09:08] [PASSED] drm_sched_basic_timeout
> [14:09:08] ========== [PASSED] drm_sched_basic_timeout_tests
> ==========
> [14:09:08] ======= drm_sched_basic_priority_tests (2 subtests)
> ========
> [14:09:10] [PASSED] drm_sched_priorities
> [14:09:10] [PASSED] drm_sched_change_priority
> [14:09:10] ========= [PASSED] drm_sched_basic_priority_tests
> ==========
> [14:09:10] ====== drm_sched_basic_modify_sched_tests (1 subtest)
> ======
> [14:09:11] [PASSED] drm_sched_test_modify_sched
> [14:09:11] ======= [PASSED] drm_sched_basic_modify_sched_tests
> ========
> [14:09:11] ======== drm_sched_basic_credits_tests (1 subtest)
> =========
> [14:09:12] [PASSED] drm_sched_test_credits
> [14:09:12] ========== [PASSED] drm_sched_basic_credits_tests
> ==========
> [14:09:12]
> ============================================================
> [14:09:12] Testing complete. Ran 11 tests: passed: 11
> [14:09:13] Elapsed time: 13.539s total, 0.001s configuring, 3.004s
> building, 10.462s running
> 
> v2:
>  * Parameterize a bunch of similar tests.
>  * Improve test commentary.
>  * Rename TDR test to timeout. (Christian)
>  * Improve quality and consistency of naming. (Philipp)
> 
> RFC v2 -> series v1:
>  * Rebased for drm_sched_init changes.
>  * Fixed modular build.
>  * Added some comments.
>  * Filename renames. (Philipp)
> 
> v2:
>  * Dealt with a bunch of checkpatch warnings.
> 
> v3:
>  * Some mock API renames, kerneldoc grammar fixes and indentation
> fixes.
> 
> v4:
>  * Fix use after free caused by relying on scheduler fence for
> querying status.
>  * Kerneldoc fixes.
> 
> v5:
>  * Cleanup in-flight jobs on scheduler shutdown.
>  * Change hang_limit to 1.
> 
> v6:
>  * Use KUNIT_ASSERT_TRUE/FALSE.
>  * Fixed patch titles.
>  * Added credit_limit test.

Please don't add new tests in a settled series. Doing so may seem
efficient, but causes another round of review and can cause you and me
trouble when trying to find the cause of issues such as the one
mentioned below:

>  * Added CONFIG_DRM_SCHED_KUNIT_TEST_ASPIRATIONAL.
> 
> v7:
>  * v6 omitted to send the first patch by mistake.

I either see a new NULL ptr deref added through the new test or an old
one that has slipped us. My test setup is unchanged.

On which commit do you apply and test this series? Tell me, then I test again.


P.


[    3.902457] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
[    3.903376] Loaded X.509 cert 'wens: 61c038651aabdcf94bd0ac7ff06c7248db18c600'
[    3.904064] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
[    3.904673] cfg80211: failed to load regulatory.db
[    3.905037] ALSA device list:
[    3.905376]   No soundcards found.
[    3.905631] KTAP version 1
[    3.905834] 1..17
[    3.906732]     KTAP version 1
[    3.906999]     # Subtest: kunit_executor_test
[    3.907335]     # module: kunit
[    3.907337]     1..8
[    3.908476]     ok 1 parse_filter_test
[    3.909064]     ok 2 filter_suites_test
[    3.909801]     ok 3 filter_suites_test_glob_test
[    3.910678]     ok 4 filter_suites_to_empty_test
[    3.911621]     ok 5 parse_filter_attr_test
[    3.912641]     ok 6 filter_attr_test
[    3.913511]     ok 7 filter_attr_empty_test
[    3.914081]     ok 8 filter_attr_skip_test
[    3.914400] # kunit_executor_test: pass:8 fail:0 skip:0 total:8
[    3.914685] # Totals: pass:8 fail:0 skip:0 total:8
[    3.915121] ok 1 kunit_executor_test
[    3.915736]     KTAP version 1
[    3.915949]     # Subtest: kunit-try-catch-test
[    3.916314]     # module: kunit_test
[    3.916315]     1..2
[    3.917655]     ok 1 kunit_test_try_catch_successful_try_no_catch
[    3.917979]     ok 2 kunit_test_try_catch_unsuccessful_try_does_catch
[    3.918630] # kunit-try-catch-test: pass:2 fail:0 skip:0 total:2
[    3.919118] # Totals: pass:2 fail:0 skip:0 total:2
[    3.919578] ok 2 kunit-try-catch-test
[    3.920248]     KTAP version 1
[    3.920473]     # Subtest: kunit-resource-test
[    3.920796]     # module: kunit_test
[    3.920797]     1..12
[    3.921565]     ok 1 kunit_resource_test_init_resources
[    3.921793]     ok 2 kunit_resource_test_alloc_resource
[    3.922449]     ok 3 kunit_resource_test_destroy_resource
[    3.923013]     ok 4 kunit_resource_test_remove_resource
[    3.924438]     ok 5 kunit_resource_test_cleanup_resources
[    3.925834]     ok 6 kunit_resource_test_proper_free_ordering
[    3.926700]     ok 7 kunit_resource_test_static
[    3.927588]     ok 8 kunit_resource_test_named
[    3.928244]     ok 9 kunit_resource_test_action
[    3.928774]     ok 10 kunit_resource_test_remove_action
[    3.929309]     ok 11 kunit_resource_test_release_action
[    3.929826] action_order_2
[    3.930325] action_order_2
[    3.930521] action_order_1
[    3.931007]     ok 12 kunit_resource_test_action_ordering
[    3.931308] # kunit-resource-test: pass:12 fail:0 skip:0 total:12
[    3.931702] # Totals: pass:12 fail:0 skip:0 total:12
[    3.932183] ok 3 kunit-resource-test
[    3.932809]     KTAP version 1
[    3.933040]     # Subtest: kunit-log-test
[    3.933367]     # module: kunit_test
[    3.933368]     1..2
[    3.934030] put this in log.
[    3.934033] this too.
[    3.934305] add to suite log.
[    3.934500] along with this.
[    3.934982]     ok 1 kunit_log_test
[    3.935405]     # kunit_log_newline_test: Add newline
[    3.936164]     ok 2 kunit_log_newline_test # SKIP only useful when debugfs is enabled
[    3.936166] # kunit-log-test: pass:1 fail:0 skip:1 total:2
[    3.936752] # Totals: pass:1 fail:0 skip:1 total:2
[    3.937197] ok 4 kunit-log-test
[    3.937776]     KTAP version 1
[    3.938004]     # Subtest: kunit_status
[    3.938324]     # module: kunit_test
[    3.938325]     1..2
[    3.938921]     ok 1 kunit_status_set_failure_test
[    3.939049]     ok 2 kunit_status_mark_skipped_test
[    3.939445] # kunit_status: pass:2 fail:0 skip:0 total:2
[    3.939816] # Totals: pass:2 fail:0 skip:0 total:2
[    3.940436] ok 5 kunit_status
[    3.941142]     KTAP version 1
[    3.941508]     # Subtest: kunit_current
[    3.941793]     # module: kunit_test
[    3.941794]     1..2
[    3.942526]     ok 1 kunit_current_test
[    3.942596]     # fake test: lib/kunit/kunit-test.c:722: This should make `fake` test fail.
[    3.943302]     ok 2 kunit_current_fail_test
[    3.943908] # kunit_current: pass:2 fail:0 skip:0 total:2
[    3.944271] # Totals: pass:2 fail:0 skip:0 total:2
[    3.944661] ok 6 kunit_current
[    3.945285]     KTAP version 1
[    3.945511]     # Subtest: kunit_device
[    3.945789]     # module: kunit_test
[    3.945790]     1..3
[    3.946905]     ok 1 kunit_device_test
[    3.947420]     ok 2 kunit_device_cleanup_test
[    3.948621]     ok 3 kunit_device_driver_test
[    3.948972] # kunit_device: pass:3 fail:0 skip:0 total:3
[    3.949349] # Totals: pass:3 fail:0 skip:0 total:3
[    3.949760] ok 7 kunit_device
[    3.950395]     KTAP version 1
[    3.950617]     # Subtest: kunit_fault
[    3.950889]     # module: kunit_test
[    3.950890]     1..1
[    3.951773] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
[    3.952672] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[    3.953239] CPU: 2 UID: 0 PID: 225 Comm: kunit_try_catch Tainted: G                 N 6.14.0-rc4-00388-g712b7c2f4d5d #21
[    3.954000] Tainted: [N]=TEST
[    3.954245] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
[    3.954850] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
[    3.955285] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42 04 01 f3 f3 f3 <0f> b6 04
[    3.956604] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
[    3.956972] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX: ffffffffb65da11d
[    3.957651] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI: ffff88810088fb30
[    3.958317] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09: ffffed10207de600
[    3.958849] R10: ffff888103ef3007 R11: 0000000000000000 R12: ffffffffb73baf40
[    3.959425] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15: ffff8881091c6ac0
[    3.959917] FS:  0000000000000000(0000) GS:ffff888a88700000(0000) knlGS:0000000000000000
[    3.960521] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.960920] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4: 00000000000006f0
[    3.961480] Call Trace:
[    3.961655]  <TASK>
[    3.961805]  ? die_addr+0x3b/0xa0
[    3.962052]  ? exc_general_protection+0x151/0x220
[    3.962439]  ? asm_exc_general_protection+0x26/0x30
[    3.962801]  ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
[    3.963447]  ? __pfx_kunit_test_null_dereference+0x10/0x10
[    3.964150]  ? __kthread_parkme+0x7d/0x140
[    3.964443]  ? kunit_test_null_dereference+0x4a/0x150
[    3.964785]  ? __pfx_kunit_test_null_dereference+0x10/0x10
[    3.965205]  ? __kthread_parkme+0x7d/0x140
[    3.965494]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
[    3.965859]  kthread+0x30f/0x620
[    3.966108]  ? __pfx_kthread+0x10/0x10
[    3.966406]  ? __pfx_kthread+0x10/0x10
[    3.966680]  ret_from_fork+0x2f/0x70
[    3.966941]  ? __pfx_kthread+0x10/0x10
[    3.967264]  ret_from_fork_asm+0x1a/0x30
[    3.967560]  </TASK>
[    3.967722] Modules linked in:
[    3.967989] ---[ end trace 0000000000000000 ]---
[    3.968368] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
[    3.968780] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42 04 01 f3 f3 f3 <0f> b6 04
[    3.970211] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
[    3.970567] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX: ffffffffb65da11d
[    3.971074] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI: ffff88810088fb30
[    3.971580] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09: ffffed10207de600
[    3.972089] R10: ffff888103ef3007 R11: 0000000000000000 R12: ffffffffb73baf40
[    3.972629] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15: ffff8881091c6ac0
[    3.973176] FS:  0000000000000000(0000) GS:ffff888a88700000(0000) knlGS:0000000000000000
[    3.973720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    3.974148] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4: 00000000000006f0
[    3.974659] kunit_try_catch (225) used greatest stack depth: 28416 bytes left
[    3.974764]     # kunit_test_fault_null_dereference: try faulted: last line seen lib/kunit/kunit-test.c:95
[    3.976367]     ok 1 kunit_test_fault_null_dereference
[    3.976370] ok 8 kunit_fault
[    3.976946]     KTAP version 1
[    3.977208]     # Subtest: kunit_platform_device
[    3.977549]     # module: platform_test
[    3.977550]     1..4
[    3.978550]     ok 1 kunit_platform_device_alloc_test
[    3.978989]     ok 2 kunit_platform_device_add_test
[    3.980097] sysfs: cannot create duplicate filename '/devices/platform/kunit-platform-add-2'
[    3.981138] CPU: 7 UID: 0 PID: 231 Comm: kunit_try_catch Tainted: G      D          N 6.14.0-rc4-00388-g712b7c2f4d5d #21
[    3.981142] Tainted: [D]=DIE, [N]=TEST
[    3.981143] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
[    3.981144] Call Trace:
[    3.981145]  <TASK>
[    3.981146]  dump_stack_lvl+0x53/0x70
[    3.981151]  sysfs_warn_dup+0x70/0x90
[    3.981154]  sysfs_create_dir_ns+0x209/0x280
[    3.981156]  ? __pfx_sysfs_create_dir_ns+0x10/0x10
[    3.981159]  ? _raw_spin_lock+0x80/0xe0
[    3.981161]  kobject_add_internal+0x216/0x8b0
[    3.981163]  kobject_add+0x13b/0x200
[    3.981165]  ? __pfx_kobject_add+0x10/0x10
[    3.981167]  ? kobject_get+0x50/0xe0
[    3.981169]  device_add+0x217/0x1460
[    3.981171]  ? __pfx_device_add+0x10/0x10
[    3.981173]  ? _raw_spin_lock_irqsave+0x86/0xe0
[    3.981174]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[    3.981176]  ? device_initialize+0x1f4/0x410
[    3.981179]  ? platform_device_alloc+0x97/0x200
[    3.981182]  platform_device_add+0x375/0x5b0
[    3.981184]  kunit_platform_device_add+0x20/0x2c0
[    3.981186]  kunit_platform_device_add_twice_fails_test+0x1f5/0x420
[    3.981189]  ? __pfx_kunit_platform_device_add_twice_fails_test+0x10/0x10
[    3.981191]  ? __schedule+0xdda/0x24f0
[    3.981193]  ? kvm_clock_get_cycles+0x18/0x30
[    3.981196]  ? ktime_get_ts64+0x7d/0x220
[    3.981200]  kunit_try_run_case+0x1ae/0x490
[    3.981202]  ? __pfx_kunit_try_run_case+0x10/0x10
[    3.981204]  ? _raw_spin_lock_irqsave+0x86/0xe0
[    3.981205]  ? __pfx_kunit_try_run_case+0x10/0x10
[    3.981207]  ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
[    3.981210]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
[    3.981212]  kthread+0x30f/0x620
[    3.981214]  ? __pfx_kthread+0x10/0x10
[    3.981216]  ? __pfx_kthread+0x10/0x10
[    3.981217]  ret_from_fork+0x2f/0x70
[    3.981223]  ? __pfx_kthread+0x10/0x10
[    3.981225]  ret_from_fork_asm+0x1a/0x30
[    3.981227]  </TASK>
[    3.981232] kobject: kobject_add_internal failed for kunit-platform-add-2 with -EEXIST, don't try to register things with the same name in the same direc.
[    3.995255] kunit_try_catch (231) used greatest stack depth: 27528 bytes left
[    3.995525]     ok 3 kunit_platform_device_add_twice_fails_test
[    3.996247]     ok 4 kunit_platform_device_add_cleans_up
[    3.996678] # kunit_platform_device: pass:4 fail:0 skip:0 total:4
[    3.997073] # Totals: pass:4 fail:0 skip:0 total:4
[    3.997530] ok 9 kunit_platform_device
[    3.998130]     KTAP version 1
[    3.998356]     # Subtest: kunit_platform_driver
[    3.998664]     # module: platform_test
[    3.998665]     1..2
[    3.999663]     ok 1 kunit_platform_driver_register_test
[    4.000372]     ok 2 kunit_platform_device_prepare_wait_for_probe_completes_when_already_probed
[    4.000750] # kunit_platform_driver: pass:2 fail:0 skip:0 total:2
[    4.001372] # Totals: pass:2 fail:0 skip:0 total:2
[    4.001777] ok 10 kunit_platform_driver
[    4.002412]     KTAP version 1
[    4.002618]     # Subtest: string-stream-test
[    4.002909]     # module: string_stream_test
[    4.002910]     1..12
[    4.003643]     ok 1 string_stream_managed_init_test
[    4.003919]     ok 2 string_stream_unmanaged_init_test
[    4.004581]     ok 3 string_stream_managed_free_test
[    4.005295]     ok 4 string_stream_resource_free_test
[    4.007076]     ok 5 string_stream_line_add_test
[    4.008801]     ok 6 string_stream_variable_length_line_test
[    4.009944]     ok 7 string_stream_append_test
[    4.010840]     ok 8 string_stream_append_auto_newline_test
[    4.011461]     ok 9 string_stream_append_empty_string_test
[    4.012233]     ok 10 string_stream_no_auto_newline_test
[    4.013158]     ok 11 string_stream_auto_newline_test
[    4.063760]     # string_stream_performance_test: Time elapsed:           49385 us
[    4.064713]     # string_stream_performance_test: Total string length:    573890
[    4.065271]     # string_stream_performance_test: Bytes requested:        823930
[    4.065803]     # string_stream_performance_test: Actual bytes allocated: 1048312
[    4.098820]     ok 12 string_stream_performance_test
[    4.098826] # string-stream-test: pass:12 fail:0 skip:0 total:12
[    4.099348] # Totals: pass:12 fail:0 skip:0 total:12
[    4.099814] ok 11 string-stream-test
[    4.100495]     KTAP version 1
[    4.100735]     # Subtest: kunit-assert
[    4.101048]     # module: assert_test
[    4.101050]     1..11
[    4.101943]     ok 1 kunit_test_is_literal
[    4.102331]     ok 2 kunit_test_is_str_literal
[    4.103177]     ok 3 kunit_test_assert_prologue
[    4.103996]     ok 4 kunit_test_assert_print_msg
[    4.104867]     ok 5 kunit_test_unary_assert_format
[    4.105908]     ok 6 kunit_test_ptr_not_err_assert_format
[    4.107022]     ok 7 kunit_test_binary_assert_format
[    4.107868]     ok 8 kunit_test_binary_ptr_assert_format
[    4.108702]     ok 9 kunit_test_binary_str_assert_format
[    4.109969]     ok 10 kunit_test_assert_hexdump
[    4.111490]     ok 11 kunit_test_mem_assert_format
[    4.111845] # kunit-assert: pass:11 fail:0 skip:0 total:11
[    4.112522] # Totals: pass:11 fail:0 skip:0 total:11
[    4.112949] ok 12 kunit-assert
[    4.113628]     KTAP version 1
[    4.113867]     # Subtest: drm_sched_basic_tests
[    4.114281]     # module: drm_sched_tests
[    4.114283]     1..3
[    4.234223] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input3
[    4.617191]     ok 1 drm_sched_basic_submit
[    4.617197]         KTAP version 1
[    4.617765]         # Subtest: drm_sched_basic_test
[    4.719657]         ok 1 A queue of jobs in a single entity
[    4.821976]         ok 2 A chain of dependent jobs across multiple entities
[    4.924015]         ok 3 Multiple independent job queues
[    5.026465]         ok 4 Multiple inter-dependent job queues
[    5.026907]     # drm_sched_basic_test: pass:4 fail:0 skip:0 total:4
[    5.027322]     ok 2 drm_sched_basic_test
[    5.080020]     ok 3 drm_sched_basic_entity_cleanup
[    5.080317] # drm_sched_basic_tests: pass:3 fail:0 skip:0 total:3
[    5.080657] # Totals: pass:6 fail:0 skip:0 total:6
[    5.081103] ok 13 drm_sched_basic_tests
[    5.081679]     KTAP version 1
[    5.081881]     # Subtest: drm_sched_basic_timeout_tests
[    5.082259]     # module: drm_sched_tests
[    5.082260]     1..1



> 
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Danilo Krummrich <dakr@kernel.org>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: Philipp Stanner <phasta@kernel.org>
> 
> Tvrtko Ursulin (7):
>   drm: Move some options to separate new Kconfig
>   drm/sched: Add scheduler unit testing infrastructure and some basic
>     tests
>   drm/sched: Add aspirational unit test mode
>   drm/sched: Add a simple timeout test
>   drm/sched: Add basic priority tests
>   drm/sched: Add a basic test for modifying entities scheduler list
>   drm/sched: Add a basic test for checking credit limit
> 
>  drivers/gpu/drm/Kconfig                       | 109 +---
>  drivers/gpu/drm/Kconfig.debug                 | 128 +++++
>  drivers/gpu/drm/scheduler/.kunitconfig        |  12 +
>  drivers/gpu/drm/scheduler/Makefile            |   2 +
>  drivers/gpu/drm/scheduler/tests/Makefile      |   7 +
>  .../gpu/drm/scheduler/tests/mock_scheduler.c  | 345 +++++++++++++
>  drivers/gpu/drm/scheduler/tests/sched_tests.h | 224 +++++++++
>  drivers/gpu/drm/scheduler/tests/tests_basic.c | 476
> ++++++++++++++++++
>  8 files changed, 1199 insertions(+), 104 deletions(-)
>  create mode 100644 drivers/gpu/drm/Kconfig.debug
>  create mode 100644 drivers/gpu/drm/scheduler/.kunitconfig
>  create mode 100644 drivers/gpu/drm/scheduler/tests/Makefile
>  create mode 100644 drivers/gpu/drm/scheduler/tests/mock_scheduler.c
>  create mode 100644 drivers/gpu/drm/scheduler/tests/sched_tests.h
>  create mode 100644 drivers/gpu/drm/scheduler/tests/tests_basic.c
>
Tvrtko Ursulin March 12, 2025, 10:50 a.m. UTC | #2
On 12/03/2025 10:39, Philipp Stanner wrote:
> On Tue, 2025-03-11 at 09:23 +0000, Tvrtko Ursulin wrote:
>> There has repeatedly been quite a bit of apprehension when any change
>> to the DRM
>> scheduler is proposed, with two main reasons being code base is
>> considered
>> fragile, not well understood and not very well documented, and
>> secondly the lack
>> of systematic testing outside the vendor specific tests suites and/or
>> test
>> farms.
>>
>> This series is an attempt to dislodge this status quo by adding some
>> unit tests
>> using the kunit framework.
>>
>> General approach is that there is a mock "hardware" backend which can
>> be
>> controlled from tests, which in turn allows exercising various
>> scheduler code
>> paths.
>>
>> Only some simple basic tests get added in the series and hopefully it
>> is easy to
>> understand what tests are doing.
>>
>> An obligatory "screenshot" for reference:
>>
>> [14:09:05] ============ drm_sched_basic_tests (3 subtests)
>> ============
>> [14:09:06] [PASSED] drm_sched_basic_submit
>> [14:09:06] ================== drm_sched_basic_test
>> ===================
>> [14:09:06] [PASSED] A queue of jobs in a single entity
>> [14:09:06] [PASSED] A chain of dependent jobs across multiple
>> entities
>> [14:09:06] [PASSED] Multiple independent job queues
>> [14:09:06] [PASSED] Multiple inter-dependent job queues
>> [14:09:07] ============== [PASSED] drm_sched_basic_test
>> ===============
>> [14:09:07] [PASSED] drm_sched_basic_entity_cleanup
>> [14:09:07] ============== [PASSED] drm_sched_basic_tests
>> ==============
>> [14:09:07] ======== drm_sched_basic_timeout_tests (1 subtest)
>> =========
>> [14:09:08] [PASSED] drm_sched_basic_timeout
>> [14:09:08] ========== [PASSED] drm_sched_basic_timeout_tests
>> ==========
>> [14:09:08] ======= drm_sched_basic_priority_tests (2 subtests)
>> ========
>> [14:09:10] [PASSED] drm_sched_priorities
>> [14:09:10] [PASSED] drm_sched_change_priority
>> [14:09:10] ========= [PASSED] drm_sched_basic_priority_tests
>> ==========
>> [14:09:10] ====== drm_sched_basic_modify_sched_tests (1 subtest)
>> ======
>> [14:09:11] [PASSED] drm_sched_test_modify_sched
>> [14:09:11] ======= [PASSED] drm_sched_basic_modify_sched_tests
>> ========
>> [14:09:11] ======== drm_sched_basic_credits_tests (1 subtest)
>> =========
>> [14:09:12] [PASSED] drm_sched_test_credits
>> [14:09:12] ========== [PASSED] drm_sched_basic_credits_tests
>> ==========
>> [14:09:12]
>> ============================================================
>> [14:09:12] Testing complete. Ran 11 tests: passed: 11
>> [14:09:13] Elapsed time: 13.539s total, 0.001s configuring, 3.004s
>> building, 10.462s running
>>
>> v2:
>>   * Parameterize a bunch of similar tests.
>>   * Improve test commentary.
>>   * Rename TDR test to timeout. (Christian)
>>   * Improve quality and consistency of naming. (Philipp)
>>
>> RFC v2 -> series v1:
>>   * Rebased for drm_sched_init changes.
>>   * Fixed modular build.
>>   * Added some comments.
>>   * Filename renames. (Philipp)
>>
>> v2:
>>   * Dealt with a bunch of checkpatch warnings.
>>
>> v3:
>>   * Some mock API renames, kerneldoc grammar fixes and indentation
>> fixes.
>>
>> v4:
>>   * Fix use after free caused by relying on scheduler fence for
>> querying status.
>>   * Kerneldoc fixes.
>>
>> v5:
>>   * Cleanup in-flight jobs on scheduler shutdown.
>>   * Change hang_limit to 1.
>>
>> v6:
>>   * Use KUNIT_ASSERT_TRUE/FALSE.
>>   * Fixed patch titles.
>>   * Added credit_limit test.
> 
> Please don't add new tests in a settled series. Doing so may seem
> efficient, but causes another round of review and can cause you and me
> trouble when trying to find the cause of issues such as the one
> mentioned below:
> 
>>   * Added CONFIG_DRM_SCHED_KUNIT_TEST_ASPIRATIONAL.
>>
>> v7:
>>   * v6 omitted to send the first patch by mistake.
> 
> I either see a new NULL ptr deref added through the new test or an old
> one that has slipped us. My test setup is unchanged.

All I see in what you pasted are kunit_test_null_dereference "crashes". 
Ie. expected ones from having enabled CONFIG_KUNIT_FAULT_TEST.

Is there something more that you did not paste?

> On which commit do you apply and test this series? Tell me, then I test again.

Depending on the setup, these three:

commit 413ae464b8021542ad90cb1fbb15f8efc5050a5d
Author: Thomas Zimmermann <tzimmermann@suse.de>
Date:   Mon Mar 3 16:41:48 2025 +0100

     drm-tip: 2025y-03m-03d-15h-40m-53s UTC integration manifest

commit 5bcb67a2a4c61034f5a25c024631c5fbf351ee8d
Author: Matt Coster <matt.coster@imgtec.com>
Date:   Wed Feb 26 10:01:09 2025 +0000

     drm-tip: 2025y-02m-26d-09h-59m-48s UTC integration manifest

commit 777e1850811f9864aa8b55940634d3da19712bf7
Author: Imre Deak <imre.deak@intel.com>
Date:   Tue Mar 11 11:31:04 2025 +0200

     drm-tip: 2025y-03m-11d-09h-30m-13s UTC integration manifest

Regards,

Tvrtko

> [    3.902457] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
> [    3.903376] Loaded X.509 cert 'wens: 61c038651aabdcf94bd0ac7ff06c7248db18c600'
> [    3.904064] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
> [    3.904673] cfg80211: failed to load regulatory.db
> [    3.905037] ALSA device list:
> [    3.905376]   No soundcards found.
> [    3.905631] KTAP version 1
> [    3.905834] 1..17
> [    3.906732]     KTAP version 1
> [    3.906999]     # Subtest: kunit_executor_test
> [    3.907335]     # module: kunit
> [    3.907337]     1..8
> [    3.908476]     ok 1 parse_filter_test
> [    3.909064]     ok 2 filter_suites_test
> [    3.909801]     ok 3 filter_suites_test_glob_test
> [    3.910678]     ok 4 filter_suites_to_empty_test
> [    3.911621]     ok 5 parse_filter_attr_test
> [    3.912641]     ok 6 filter_attr_test
> [    3.913511]     ok 7 filter_attr_empty_test
> [    3.914081]     ok 8 filter_attr_skip_test
> [    3.914400] # kunit_executor_test: pass:8 fail:0 skip:0 total:8
> [    3.914685] # Totals: pass:8 fail:0 skip:0 total:8
> [    3.915121] ok 1 kunit_executor_test
> [    3.915736]     KTAP version 1
> [    3.915949]     # Subtest: kunit-try-catch-test
> [    3.916314]     # module: kunit_test
> [    3.916315]     1..2
> [    3.917655]     ok 1 kunit_test_try_catch_successful_try_no_catch
> [    3.917979]     ok 2 kunit_test_try_catch_unsuccessful_try_does_catch
> [    3.918630] # kunit-try-catch-test: pass:2 fail:0 skip:0 total:2
> [    3.919118] # Totals: pass:2 fail:0 skip:0 total:2
> [    3.919578] ok 2 kunit-try-catch-test
> [    3.920248]     KTAP version 1
> [    3.920473]     # Subtest: kunit-resource-test
> [    3.920796]     # module: kunit_test
> [    3.920797]     1..12
> [    3.921565]     ok 1 kunit_resource_test_init_resources
> [    3.921793]     ok 2 kunit_resource_test_alloc_resource
> [    3.922449]     ok 3 kunit_resource_test_destroy_resource
> [    3.923013]     ok 4 kunit_resource_test_remove_resource
> [    3.924438]     ok 5 kunit_resource_test_cleanup_resources
> [    3.925834]     ok 6 kunit_resource_test_proper_free_ordering
> [    3.926700]     ok 7 kunit_resource_test_static
> [    3.927588]     ok 8 kunit_resource_test_named
> [    3.928244]     ok 9 kunit_resource_test_action
> [    3.928774]     ok 10 kunit_resource_test_remove_action
> [    3.929309]     ok 11 kunit_resource_test_release_action
> [    3.929826] action_order_2
> [    3.930325] action_order_2
> [    3.930521] action_order_1
> [    3.931007]     ok 12 kunit_resource_test_action_ordering
> [    3.931308] # kunit-resource-test: pass:12 fail:0 skip:0 total:12
> [    3.931702] # Totals: pass:12 fail:0 skip:0 total:12
> [    3.932183] ok 3 kunit-resource-test
> [    3.932809]     KTAP version 1
> [    3.933040]     # Subtest: kunit-log-test
> [    3.933367]     # module: kunit_test
> [    3.933368]     1..2
> [    3.934030] put this in log.
> [    3.934033] this too.
> [    3.934305] add to suite log.
> [    3.934500] along with this.
> [    3.934982]     ok 1 kunit_log_test
> [    3.935405]     # kunit_log_newline_test: Add newline
> [    3.936164]     ok 2 kunit_log_newline_test # SKIP only useful when debugfs is enabled
> [    3.936166] # kunit-log-test: pass:1 fail:0 skip:1 total:2
> [    3.936752] # Totals: pass:1 fail:0 skip:1 total:2
> [    3.937197] ok 4 kunit-log-test
> [    3.937776]     KTAP version 1
> [    3.938004]     # Subtest: kunit_status
> [    3.938324]     # module: kunit_test
> [    3.938325]     1..2
> [    3.938921]     ok 1 kunit_status_set_failure_test
> [    3.939049]     ok 2 kunit_status_mark_skipped_test
> [    3.939445] # kunit_status: pass:2 fail:0 skip:0 total:2
> [    3.939816] # Totals: pass:2 fail:0 skip:0 total:2
> [    3.940436] ok 5 kunit_status
> [    3.941142]     KTAP version 1
> [    3.941508]     # Subtest: kunit_current
> [    3.941793]     # module: kunit_test
> [    3.941794]     1..2
> [    3.942526]     ok 1 kunit_current_test
> [    3.942596]     # fake test: lib/kunit/kunit-test.c:722: This should make `fake` test fail.
> [    3.943302]     ok 2 kunit_current_fail_test
> [    3.943908] # kunit_current: pass:2 fail:0 skip:0 total:2
> [    3.944271] # Totals: pass:2 fail:0 skip:0 total:2
> [    3.944661] ok 6 kunit_current
> [    3.945285]     KTAP version 1
> [    3.945511]     # Subtest: kunit_device
> [    3.945789]     # module: kunit_test
> [    3.945790]     1..3
> [    3.946905]     ok 1 kunit_device_test
> [    3.947420]     ok 2 kunit_device_cleanup_test
> [    3.948621]     ok 3 kunit_device_driver_test
> [    3.948972] # kunit_device: pass:3 fail:0 skip:0 total:3
> [    3.949349] # Totals: pass:3 fail:0 skip:0 total:3
> [    3.949760] ok 7 kunit_device
> [    3.950395]     KTAP version 1
> [    3.950617]     # Subtest: kunit_fault
> [    3.950889]     # module: kunit_test
> [    3.950890]     1..1
> [    3.951773] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
> [    3.952672] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> [    3.953239] CPU: 2 UID: 0 PID: 225 Comm: kunit_try_catch Tainted: G                 N 6.14.0-rc4-00388-g712b7c2f4d5d #21
> [    3.954000] Tainted: [N]=TEST
> [    3.954245] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
> [    3.954850] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
> [    3.955285] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42 04 01 f3 f3 f3 <0f> b6 04
> [    3.956604] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
> [    3.956972] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX: ffffffffb65da11d
> [    3.957651] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI: ffff88810088fb30
> [    3.958317] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09: ffffed10207de600
> [    3.958849] R10: ffff888103ef3007 R11: 0000000000000000 R12: ffffffffb73baf40
> [    3.959425] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15: ffff8881091c6ac0
> [    3.959917] FS:  0000000000000000(0000) GS:ffff888a88700000(0000) knlGS:0000000000000000
> [    3.960521] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    3.960920] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4: 00000000000006f0
> [    3.961480] Call Trace:
> [    3.961655]  <TASK>
> [    3.961805]  ? die_addr+0x3b/0xa0
> [    3.962052]  ? exc_general_protection+0x151/0x220
> [    3.962439]  ? asm_exc_general_protection+0x26/0x30
> [    3.962801]  ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
> [    3.963447]  ? __pfx_kunit_test_null_dereference+0x10/0x10
> [    3.964150]  ? __kthread_parkme+0x7d/0x140
> [    3.964443]  ? kunit_test_null_dereference+0x4a/0x150
> [    3.964785]  ? __pfx_kunit_test_null_dereference+0x10/0x10
> [    3.965205]  ? __kthread_parkme+0x7d/0x140
> [    3.965494]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> [    3.965859]  kthread+0x30f/0x620
> [    3.966108]  ? __pfx_kthread+0x10/0x10
> [    3.966406]  ? __pfx_kthread+0x10/0x10
> [    3.966680]  ret_from_fork+0x2f/0x70
> [    3.966941]  ? __pfx_kthread+0x10/0x10
> [    3.967264]  ret_from_fork_asm+0x1a/0x30
> [    3.967560]  </TASK>
> [    3.967722] Modules linked in:
> [    3.967989] ---[ end trace 0000000000000000 ]---
> [    3.968368] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
> [    3.968780] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42 04 01 f3 f3 f3 <0f> b6 04
> [    3.970211] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
> [    3.970567] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX: ffffffffb65da11d
> [    3.971074] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI: ffff88810088fb30
> [    3.971580] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09: ffffed10207de600
> [    3.972089] R10: ffff888103ef3007 R11: 0000000000000000 R12: ffffffffb73baf40
> [    3.972629] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15: ffff8881091c6ac0
> [    3.973176] FS:  0000000000000000(0000) GS:ffff888a88700000(0000) knlGS:0000000000000000
> [    3.973720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    3.974148] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4: 00000000000006f0
> [    3.974659] kunit_try_catch (225) used greatest stack depth: 28416 bytes left
> [    3.974764]     # kunit_test_fault_null_dereference: try faulted: last line seen lib/kunit/kunit-test.c:95
> [    3.976367]     ok 1 kunit_test_fault_null_dereference
> [    3.976370] ok 8 kunit_fault
> [    3.976946]     KTAP version 1
> [    3.977208]     # Subtest: kunit_platform_device
> [    3.977549]     # module: platform_test
> [    3.977550]     1..4
> [    3.978550]     ok 1 kunit_platform_device_alloc_test
> [    3.978989]     ok 2 kunit_platform_device_add_test
> [    3.980097] sysfs: cannot create duplicate filename '/devices/platform/kunit-platform-add-2'
> [    3.981138] CPU: 7 UID: 0 PID: 231 Comm: kunit_try_catch Tainted: G      D          N 6.14.0-rc4-00388-g712b7c2f4d5d #21
> [    3.981142] Tainted: [D]=DIE, [N]=TEST
> [    3.981143] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
> [    3.981144] Call Trace:
> [    3.981145]  <TASK>
> [    3.981146]  dump_stack_lvl+0x53/0x70
> [    3.981151]  sysfs_warn_dup+0x70/0x90
> [    3.981154]  sysfs_create_dir_ns+0x209/0x280
> [    3.981156]  ? __pfx_sysfs_create_dir_ns+0x10/0x10
> [    3.981159]  ? _raw_spin_lock+0x80/0xe0
> [    3.981161]  kobject_add_internal+0x216/0x8b0
> [    3.981163]  kobject_add+0x13b/0x200
> [    3.981165]  ? __pfx_kobject_add+0x10/0x10
> [    3.981167]  ? kobject_get+0x50/0xe0
> [    3.981169]  device_add+0x217/0x1460
> [    3.981171]  ? __pfx_device_add+0x10/0x10
> [    3.981173]  ? _raw_spin_lock_irqsave+0x86/0xe0
> [    3.981174]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> [    3.981176]  ? device_initialize+0x1f4/0x410
> [    3.981179]  ? platform_device_alloc+0x97/0x200
> [    3.981182]  platform_device_add+0x375/0x5b0
> [    3.981184]  kunit_platform_device_add+0x20/0x2c0
> [    3.981186]  kunit_platform_device_add_twice_fails_test+0x1f5/0x420
> [    3.981189]  ? __pfx_kunit_platform_device_add_twice_fails_test+0x10/0x10
> [    3.981191]  ? __schedule+0xdda/0x24f0
> [    3.981193]  ? kvm_clock_get_cycles+0x18/0x30
> [    3.981196]  ? ktime_get_ts64+0x7d/0x220
> [    3.981200]  kunit_try_run_case+0x1ae/0x490
> [    3.981202]  ? __pfx_kunit_try_run_case+0x10/0x10
> [    3.981204]  ? _raw_spin_lock_irqsave+0x86/0xe0
> [    3.981205]  ? __pfx_kunit_try_run_case+0x10/0x10
> [    3.981207]  ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
> [    3.981210]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> [    3.981212]  kthread+0x30f/0x620
> [    3.981214]  ? __pfx_kthread+0x10/0x10
> [    3.981216]  ? __pfx_kthread+0x10/0x10
> [    3.981217]  ret_from_fork+0x2f/0x70
> [    3.981223]  ? __pfx_kthread+0x10/0x10
> [    3.981225]  ret_from_fork_asm+0x1a/0x30
> [    3.981227]  </TASK>
> [    3.981232] kobject: kobject_add_internal failed for kunit-platform-add-2 with -EEXIST, don't try to register things with the same name in the same direc.
> [    3.995255] kunit_try_catch (231) used greatest stack depth: 27528 bytes left
> [    3.995525]     ok 3 kunit_platform_device_add_twice_fails_test
> [    3.996247]     ok 4 kunit_platform_device_add_cleans_up
> [    3.996678] # kunit_platform_device: pass:4 fail:0 skip:0 total:4
> [    3.997073] # Totals: pass:4 fail:0 skip:0 total:4
> [    3.997530] ok 9 kunit_platform_device
> [    3.998130]     KTAP version 1
> [    3.998356]     # Subtest: kunit_platform_driver
> [    3.998664]     # module: platform_test
> [    3.998665]     1..2
> [    3.999663]     ok 1 kunit_platform_driver_register_test
> [    4.000372]     ok 2 kunit_platform_device_prepare_wait_for_probe_completes_when_already_probed
> [    4.000750] # kunit_platform_driver: pass:2 fail:0 skip:0 total:2
> [    4.001372] # Totals: pass:2 fail:0 skip:0 total:2
> [    4.001777] ok 10 kunit_platform_driver
> [    4.002412]     KTAP version 1
> [    4.002618]     # Subtest: string-stream-test
> [    4.002909]     # module: string_stream_test
> [    4.002910]     1..12
> [    4.003643]     ok 1 string_stream_managed_init_test
> [    4.003919]     ok 2 string_stream_unmanaged_init_test
> [    4.004581]     ok 3 string_stream_managed_free_test
> [    4.005295]     ok 4 string_stream_resource_free_test
> [    4.007076]     ok 5 string_stream_line_add_test
> [    4.008801]     ok 6 string_stream_variable_length_line_test
> [    4.009944]     ok 7 string_stream_append_test
> [    4.010840]     ok 8 string_stream_append_auto_newline_test
> [    4.011461]     ok 9 string_stream_append_empty_string_test
> [    4.012233]     ok 10 string_stream_no_auto_newline_test
> [    4.013158]     ok 11 string_stream_auto_newline_test
> [    4.063760]     # string_stream_performance_test: Time elapsed:           49385 us
> [    4.064713]     # string_stream_performance_test: Total string length:    573890
> [    4.065271]     # string_stream_performance_test: Bytes requested:        823930
> [    4.065803]     # string_stream_performance_test: Actual bytes allocated: 1048312
> [    4.098820]     ok 12 string_stream_performance_test
> [    4.098826] # string-stream-test: pass:12 fail:0 skip:0 total:12
> [    4.099348] # Totals: pass:12 fail:0 skip:0 total:12
> [    4.099814] ok 11 string-stream-test
> [    4.100495]     KTAP version 1
> [    4.100735]     # Subtest: kunit-assert
> [    4.101048]     # module: assert_test
> [    4.101050]     1..11
> [    4.101943]     ok 1 kunit_test_is_literal
> [    4.102331]     ok 2 kunit_test_is_str_literal
> [    4.103177]     ok 3 kunit_test_assert_prologue
> [    4.103996]     ok 4 kunit_test_assert_print_msg
> [    4.104867]     ok 5 kunit_test_unary_assert_format
> [    4.105908]     ok 6 kunit_test_ptr_not_err_assert_format
> [    4.107022]     ok 7 kunit_test_binary_assert_format
> [    4.107868]     ok 8 kunit_test_binary_ptr_assert_format
> [    4.108702]     ok 9 kunit_test_binary_str_assert_format
> [    4.109969]     ok 10 kunit_test_assert_hexdump
> [    4.111490]     ok 11 kunit_test_mem_assert_format
> [    4.111845] # kunit-assert: pass:11 fail:0 skip:0 total:11
> [    4.112522] # Totals: pass:11 fail:0 skip:0 total:11
> [    4.112949] ok 12 kunit-assert
> [    4.113628]     KTAP version 1
> [    4.113867]     # Subtest: drm_sched_basic_tests
> [    4.114281]     # module: drm_sched_tests
> [    4.114283]     1..3
> [    4.234223] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input3
> [    4.617191]     ok 1 drm_sched_basic_submit
> [    4.617197]         KTAP version 1
> [    4.617765]         # Subtest: drm_sched_basic_test
> [    4.719657]         ok 1 A queue of jobs in a single entity
> [    4.821976]         ok 2 A chain of dependent jobs across multiple entities
> [    4.924015]         ok 3 Multiple independent job queues
> [    5.026465]         ok 4 Multiple inter-dependent job queues
> [    5.026907]     # drm_sched_basic_test: pass:4 fail:0 skip:0 total:4
> [    5.027322]     ok 2 drm_sched_basic_test
> [    5.080020]     ok 3 drm_sched_basic_entity_cleanup
> [    5.080317] # drm_sched_basic_tests: pass:3 fail:0 skip:0 total:3
> [    5.080657] # Totals: pass:6 fail:0 skip:0 total:6
> [    5.081103] ok 13 drm_sched_basic_tests
> [    5.081679]     KTAP version 1
> [    5.081881]     # Subtest: drm_sched_basic_timeout_tests
> [    5.082259]     # module: drm_sched_tests
> [    5.082260]     1..1
> 
> 
> 
>>
>> Cc: Christian König <christian.koenig@amd.com>
>> Cc: Danilo Krummrich <dakr@kernel.org>
>> Cc: Matthew Brost <matthew.brost@intel.com>
>> Cc: Philipp Stanner <phasta@kernel.org>
>>
>> Tvrtko Ursulin (7):
>>    drm: Move some options to separate new Kconfig
>>    drm/sched: Add scheduler unit testing infrastructure and some basic
>>      tests
>>    drm/sched: Add aspirational unit test mode
>>    drm/sched: Add a simple timeout test
>>    drm/sched: Add basic priority tests
>>    drm/sched: Add a basic test for modifying entities scheduler list
>>    drm/sched: Add a basic test for checking credit limit
>>
>>   drivers/gpu/drm/Kconfig                       | 109 +---
>>   drivers/gpu/drm/Kconfig.debug                 | 128 +++++
>>   drivers/gpu/drm/scheduler/.kunitconfig        |  12 +
>>   drivers/gpu/drm/scheduler/Makefile            |   2 +
>>   drivers/gpu/drm/scheduler/tests/Makefile      |   7 +
>>   .../gpu/drm/scheduler/tests/mock_scheduler.c  | 345 +++++++++++++
>>   drivers/gpu/drm/scheduler/tests/sched_tests.h | 224 +++++++++
>>   drivers/gpu/drm/scheduler/tests/tests_basic.c | 476
>> ++++++++++++++++++
>>   8 files changed, 1199 insertions(+), 104 deletions(-)
>>   create mode 100644 drivers/gpu/drm/Kconfig.debug
>>   create mode 100644 drivers/gpu/drm/scheduler/.kunitconfig
>>   create mode 100644 drivers/gpu/drm/scheduler/tests/Makefile
>>   create mode 100644 drivers/gpu/drm/scheduler/tests/mock_scheduler.c
>>   create mode 100644 drivers/gpu/drm/scheduler/tests/sched_tests.h
>>   create mode 100644 drivers/gpu/drm/scheduler/tests/tests_basic.c
>>
>
Philipp Stanner March 12, 2025, 12:35 p.m. UTC | #3
On Wed, 2025-03-12 at 10:50 +0000, Tvrtko Ursulin wrote:
> 
> On 12/03/2025 10:39, Philipp Stanner wrote:
> > On Tue, 2025-03-11 at 09:23 +0000, Tvrtko Ursulin wrote:
> > > There has repeatedly been quite a bit of apprehension when any
> > > change
> > > to the DRM
> > > scheduler is proposed, with two main reasons being code base is
> > > considered
> > > fragile, not well understood and not very well documented, and
> > > secondly the lack
> > > of systematic testing outside the vendor specific tests suites
> > > and/or
> > > test
> > > farms.
> > > 
> > > This series is an attempt to dislodge this status quo by adding
> > > some
> > > unit tests
> > > using the kunit framework.
> > > 
> > > General approach is that there is a mock "hardware" backend which
> > > can
> > > be
> > > controlled from tests, which in turn allows exercising various
> > > scheduler code
> > > paths.
> > > 
> > > Only some simple basic tests get added in the series and
> > > hopefully it
> > > is easy to
> > > understand what tests are doing.
> > > 
> > > An obligatory "screenshot" for reference:
> > > 
> > > [14:09:05] ============ drm_sched_basic_tests (3 subtests)
> > > ============
> > > [14:09:06] [PASSED] drm_sched_basic_submit
> > > [14:09:06] ================== drm_sched_basic_test
> > > ===================
> > > [14:09:06] [PASSED] A queue of jobs in a single entity
> > > [14:09:06] [PASSED] A chain of dependent jobs across multiple
> > > entities
> > > [14:09:06] [PASSED] Multiple independent job queues
> > > [14:09:06] [PASSED] Multiple inter-dependent job queues
> > > [14:09:07] ============== [PASSED] drm_sched_basic_test
> > > ===============
> > > [14:09:07] [PASSED] drm_sched_basic_entity_cleanup
> > > [14:09:07] ============== [PASSED] drm_sched_basic_tests
> > > ==============
> > > [14:09:07] ======== drm_sched_basic_timeout_tests (1 subtest)
> > > =========
> > > [14:09:08] [PASSED] drm_sched_basic_timeout
> > > [14:09:08] ========== [PASSED] drm_sched_basic_timeout_tests
> > > ==========
> > > [14:09:08] ======= drm_sched_basic_priority_tests (2 subtests)
> > > ========
> > > [14:09:10] [PASSED] drm_sched_priorities
> > > [14:09:10] [PASSED] drm_sched_change_priority
> > > [14:09:10] ========= [PASSED] drm_sched_basic_priority_tests
> > > ==========
> > > [14:09:10] ====== drm_sched_basic_modify_sched_tests (1 subtest)
> > > ======
> > > [14:09:11] [PASSED] drm_sched_test_modify_sched
> > > [14:09:11] ======= [PASSED] drm_sched_basic_modify_sched_tests
> > > ========
> > > [14:09:11] ======== drm_sched_basic_credits_tests (1 subtest)
> > > =========
> > > [14:09:12] [PASSED] drm_sched_test_credits
> > > [14:09:12] ========== [PASSED] drm_sched_basic_credits_tests
> > > ==========
> > > [14:09:12]
> > > ============================================================
> > > [14:09:12] Testing complete. Ran 11 tests: passed: 11
> > > [14:09:13] Elapsed time: 13.539s total, 0.001s configuring,
> > > 3.004s
> > > building, 10.462s running
> > > 
> > > v2:
> > >   * Parameterize a bunch of similar tests.
> > >   * Improve test commentary.
> > >   * Rename TDR test to timeout. (Christian)
> > >   * Improve quality and consistency of naming. (Philipp)
> > > 
> > > RFC v2 -> series v1:
> > >   * Rebased for drm_sched_init changes.
> > >   * Fixed modular build.
> > >   * Added some comments.
> > >   * Filename renames. (Philipp)
> > > 
> > > v2:
> > >   * Dealt with a bunch of checkpatch warnings.
> > > 
> > > v3:
> > >   * Some mock API renames, kerneldoc grammar fixes and
> > > indentation
> > > fixes.
> > > 
> > > v4:
> > >   * Fix use after free caused by relying on scheduler fence for
> > > querying status.
> > >   * Kerneldoc fixes.
> > > 
> > > v5:
> > >   * Cleanup in-flight jobs on scheduler shutdown.
> > >   * Change hang_limit to 1.
> > > 
> > > v6:
> > >   * Use KUNIT_ASSERT_TRUE/FALSE.
> > >   * Fixed patch titles.
> > >   * Added credit_limit test.
> > 
> > Please don't add new tests in a settled series. Doing so may seem
> > efficient, but causes another round of review and can cause you and
> > me
> > trouble when trying to find the cause of issues such as the one
> > mentioned below:
> > 
> > >   * Added CONFIG_DRM_SCHED_KUNIT_TEST_ASPIRATIONAL.
> > > 
> > > v7:
> > >   * v6 omitted to send the first patch by mistake.
> > 
> > I either see a new NULL ptr deref added through the new test or an
> > old
> > one that has slipped us. My test setup is unchanged.
> 
> All I see in what you pasted are kunit_test_null_dereference
> "crashes". 
> Ie. expected ones from having enabled CONFIG_KUNIT_FAULT_TEST.

Allright, didn't know about that. Help me out here quickly, so would
this option lead to a real fault on a real CPU? Or is it "simulated"?


> 
> Is there something more that you did not paste?

No, that was all.

I tried it again without the KUNIT_FAULT option and activated
aspirational mode. (on top of current drm-misc-next, eff0347e7c22).

There I see a UAF. Do you have an idea what that might be? I would only
expect memory leaks and the test assertions failing.


[    3.976637] Demotion targets for Node 0: null
[    3.977265] kmemleak: Kernel memory leak detector initialized (mem pool available: 11277)
[    3.977274] kmemleak: Automatic memory scanning thread started
[    3.978604] PM:   Magic number: 1:529:430
[    3.978914] printk: legacy console [netcon0] enabled
[    3.979247] netconsole: network logging started
[    3.979839] cfg80211: Loading compiled-in X.509 certificates for regulatory database
[    3.980811] kworker/u72:1 (156) used greatest stack depth: 28552 bytes left
[    3.981632] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
[    3.982437] Loaded X.509 cert 'wens: 61c038651aabdcf94bd0ac7ff06c7248db18c600'
[    3.983110] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
[    3.983578] KTAP version 1
[    3.983767] cfg80211: failed to load regulatory.db
[    3.983988] 1..5
[    3.984976]     KTAP version 1
[    3.985299]     # Subtest: drm_sched_basic_tests
[    3.985681]     # module: drm_sched_tests
[    3.985683]     1..3
[    4.319827] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input3
[    4.495862]     ok 1 drm_sched_basic_submit
[    4.495879]         KTAP version 1
[    4.496468]         # Subtest: drm_sched_basic_test
[    4.598388]         ok 1 A queue of jobs in a single entity
[    4.700730]         ok 2 A chain of dependent jobs across multiple entities
[    4.803439]         ok 3 Multiple independent job queues
[    4.905560]         ok 4 Multiple inter-dependent job queues
[    4.906029]     # drm_sched_basic_test: pass:4 fail:0 skip:0 total:4
[    4.906500]     ok 2 drm_sched_basic_test
[    4.959366]     # drm_sched_basic_entity_cleanup: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
[    4.959366]     Expected list_empty(&sched->job_list) to be true, but is false
[    4.961263]     # drm_sched_basic_entity_cleanup: test aborted during cleanup. continuing without cleaning up
[    4.961997]     not ok 3 drm_sched_basic_entity_cleanup
[    4.961999] # drm_sched_basic_tests: pass:2 fail:1 skip:0 total:3
[    4.962384] # Totals: pass:5 fail:1 skip:0 total:6
[    4.962823] not ok 1 drm_sched_basic_tests
[    4.963465]     KTAP version 1
[    4.963691]     # Subtest: drm_sched_basic_timeout_tests
[    4.964065]     # module: drm_sched_tests
[    4.964067]     1..1
[    6.503265]     # drm_sched_basic_timeout: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
[    6.503265]     Expected list_empty(&sched->job_list) to be true, but is false
[    6.504778]     # drm_sched_basic_timeout: test aborted during cleanup. continuing without cleaning up
[    6.505457]     not ok 1 drm_sched_basic_timeout
[    6.505460] not ok 2 drm_sched_basic_timeout_tests
[    6.506128]     KTAP version 1
[    6.506360]     # Subtest: drm_sched_basic_priority_tests
[    6.506751]     # module: drm_sched_tests
[    6.506753]     1..2
[    6.609082]     ok 1 drm_sched_priorities
[    7.614297]     ok 2 drm_sched_change_priority
[    7.614723] # drm_sched_basic_priority_tests: pass:2 fail:0 skip:0 total:2
[    7.615130] # Totals: pass:2 fail:0 skip:0 total:2
[    7.615667] ok 3 drm_sched_basic_priority_tests
[    7.616344]     KTAP version 1
[    7.616580]     # Subtest: drm_sched_basic_modify_sched_tests
[    7.617039]     # module: drm_sched_tests
[    7.617042]     1..1
[    7.926594]     # drm_sched_test_modify_sched: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
[    7.926594]     Expected list_empty(&sched->job_list) to be true, but is false
[    7.928533] ==================================================================
[    7.929065] BUG: KASAN: slab-use-after-free in timerqueue_add+0x24e/0x320
[    7.929596] Read of size 8 at addr ffff8881092ec8e8 by task swapper/5/0
[    7.930092] 
[    7.930251] CPU: 5 UID: 0 PID: 0 Comm: swapper/5 Tainted: G                 N 6.14.0-rc4-00476-ge1aa9011309e #6
[    7.930256] Tainted: [N]=TEST
[    7.930257] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
[    7.930258] Call Trace:
[    7.930260]  <IRQ>
[    7.930261]  dump_stack_lvl+0x53/0x70
[    7.930265]  print_report+0xce/0x680
[    7.930269]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[    7.930271]  ? __pfx_calc_global_load_tick+0x10/0x10
[    7.930274]  ? timerqueue_add+0x24e/0x320
[    7.930276]  kasan_report+0xe2/0x120
[    7.930278]  ? timerqueue_add+0x24e/0x320
[    7.930280]  timerqueue_add+0x24e/0x320
[    7.930281]  __hrtimer_run_queues+0x358/0x6f0
[    7.930284]  ? __pfx___hrtimer_run_queues+0x10/0x10
[    7.930286]  ? ktime_get_update_offsets_now+0x7c/0x2c0
[    7.930288]  hrtimer_interrupt+0x2cd/0x7e0
[    7.930290]  __sysvec_apic_timer_interrupt+0x88/0x260
[    7.930293]  sysvec_apic_timer_interrupt+0x67/0x80
[    7.930295]  </IRQ>
[    7.930296]  <TASK>
[    7.930296]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
[    7.930299] RIP: 0010:default_idle+0xf/0x20
[    7.930302] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d b3 d6 06 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
[    7.930304] RSP: 0000:ffff888100b8fe70 EFLAGS: 00000206
[    7.930306] RAX: ffff888a8ec80000 RBX: 0000000000000005 RCX: ffffffffbb3b7c41
[    7.930308] RDX: ffffed1151d96a83 RSI: 0000000000000004 RDI: 0000000000036334
[    7.930309] RBP: ffffed1020161d58 R08: 0000000000000001 R09: ffffed1151d96a82
[    7.930309] R10: ffff888a8ecb5413 R11: 0000000000001400 R12: ffff888100b0eac0
[    7.930310] R13: ffffffffbc7f36d0 R14: 1ffff11020171fd2 R15: 0000000000000000
[    7.930312]  ? ct_kernel_exit.constprop.0+0xa1/0xc0
[    7.930314]  default_idle_call+0x3a/0x60
[    7.930316]  do_idle+0x2f2/0x3b0
[    7.930318]  ? __pfx_do_idle+0x10/0x10
[    7.930320]  ? __switch_to+0x5cd/0xe30
[    7.930323]  cpu_startup_entry+0x4f/0x60
[    7.930324]  start_secondary+0x1b7/0x210
[    7.930326]  common_startup_64+0x12c/0x138
[    7.930328]  </TASK>
[    7.930329] 
[    7.931848]     not ok 1 drm_sched_test_modify_sched
[    7.932019] Allocated by task 187:
[    7.932285] not ok 4 drm_sched_basic_modify_sched_tests
[    7.932486]  kasan_save_stack+0x33/0x60
[    7.932835]     KTAP version 1
[    7.933153]  kasan_save_track+0x14/0x30
[    7.933156]  __kasan_kmalloc+0x8f/0xa0
[    7.933652]     # Subtest: drm_sched_basic_credits_tests
[    7.934095]  __kmalloc_noprof+0x18a/0x440
[    7.934494]     # module: drm_sched_tests
[    7.934817]  kunit_kmalloc_array+0x1b/0x50
[    7.935201]     1..1
[    7.935589]  drm_mock_sched_job_new+0x8f/0x400
[    7.935592]  drm_sched_test_modify_sched+0x1cd/0x490
[    7.950666]  kunit_try_run_case+0x1ae/0x490
[    7.950977]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
[    7.951400]  kthread+0x30f/0x620
[    7.951656]  ret_from_fork+0x2f/0x70
[    7.951936]  ret_from_fork_asm+0x1a/0x30
[    7.952250] 
[    7.952373] Freed by task 192:
[    7.952605]  kasan_save_stack+0x33/0x60
[    7.952884]  kasan_save_track+0x14/0x30
[    7.953169]  kasan_save_free_info+0x3b/0x60
[    7.953495]  __kasan_slab_free+0x37/0x50
[    7.953797]  kfree+0x12f/0x350
[    7.954035]  kunit_remove_resource+0x130/0x1f0
[    7.954379]  kunit_cleanup+0x6e/0x110
[    7.954656]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
[    7.955044]  kthread+0x30f/0x620
[    7.955286]  ret_from_fork+0x2f/0x70
[    7.955557]  ret_from_fork_asm+0x1a/0x30
[    7.955844] 
[    7.955956] The buggy address belongs to the object at ffff8881092ec800
[    7.955956]  which belongs to the cache kmalloc-512 of size 512
[    7.956883] The buggy address is located 232 bytes inside of
[    7.956883]  freed 512-byte region [ffff8881092ec800, ffff8881092eca00)
[    7.957790] 
[    7.957904] The buggy address belongs to the physical page:
[    7.958324] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1092e8
[    7.958925] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[    7.959527] flags: 0x200000000000040(head|node=0|zone=2)
[    7.959926] page_type: f5(slab)
[    7.960163] raw: 0200000000000040 ffff888100042c80 dead000000000122 0000000000000000
[    7.960743] raw: 0000000000000000 0000000080200020 00000000f5000000 0000000000000000
[    7.961304] head: 0200000000000040 ffff888100042c80 dead000000000122 0000000000000000
[    7.961880] head: 0000000000000000 0000000080200020 00000000f5000000 0000000000000000
[    7.962460] head: 0200000000000003 ffffea000424ba01 ffffffffffffffff 0000000000000000
[    7.963025] head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
[    7.963602] page dumped because: kasan: bad access detected
[    7.964001] 
[    7.964113] Memory state around the buggy address:
[    7.964481]  ffff8881092ec780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[    7.965007]  ffff8881092ec800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    7.965576] >ffff8881092ec880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    7.966120]                                                           ^
[    7.966625]  ffff8881092ec900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    7.967199]  ffff8881092ec980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    7.967734] ==================================================================
[    7.968267] Disabling lock debugging due to kernel taint
[    8.999147]     # drm_sched_test_credits: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:295
[    8.999147]     Expected list_empty(&sched->base.pending_list) to be true, but is false
[    9.001031]     not ok 1 drm_sched_test_credits
[    9.001034] not ok 5 drm_sched_basic_credits_tests



> 
> > On which commit do you apply and test this series? Tell me, then I
> > test again.
> 
> Depending on the setup, these three:
> 
> commit 413ae464b8021542ad90cb1fbb15f8efc5050a5d
> Author: Thomas Zimmermann <tzimmermann@suse.de>
> Date:   Mon Mar 3 16:41:48 2025 +0100
> 
>      drm-tip: 2025y-03m-03d-15h-40m-53s UTC integration manifest
> 
> commit 5bcb67a2a4c61034f5a25c024631c5fbf351ee8d
> Author: Matt Coster <matt.coster@imgtec.com>
> Date:   Wed Feb 26 10:01:09 2025 +0000
> 
>      drm-tip: 2025y-02m-26d-09h-59m-48s UTC integration manifest
> 
> commit 777e1850811f9864aa8b55940634d3da19712bf7
> Author: Imre Deak <imre.deak@intel.com>
> Date:   Tue Mar 11 11:31:04 2025 +0200
> 
>      drm-tip: 2025y-03m-11d-09h-30m-13s UTC integration manifest
> 
> Regards,
> 
> Tvrtko
> 
> > [    3.902457] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
> > [    3.903376] Loaded X.509 cert 'wens:
> > 61c038651aabdcf94bd0ac7ff06c7248db18c600'
> > [    3.904064] platform regulatory.0: Direct firmware load for
> > regulatory.db failed with error -2
> > [    3.904673] cfg80211: failed to load regulatory.db
> > [    3.905037] ALSA device list:
> > [    3.905376]   No soundcards found.
> > [    3.905631] KTAP version 1
> > [    3.905834] 1..17
> > [    3.906732]     KTAP version 1
> > [    3.906999]     # Subtest: kunit_executor_test
> > [    3.907335]     # module: kunit
> > [    3.907337]     1..8
> > [    3.908476]     ok 1 parse_filter_test
> > [    3.909064]     ok 2 filter_suites_test
> > [    3.909801]     ok 3 filter_suites_test_glob_test
> > [    3.910678]     ok 4 filter_suites_to_empty_test
> > [    3.911621]     ok 5 parse_filter_attr_test
> > [    3.912641]     ok 6 filter_attr_test
> > [    3.913511]     ok 7 filter_attr_empty_test
> > [    3.914081]     ok 8 filter_attr_skip_test
> > [    3.914400] # kunit_executor_test: pass:8 fail:0 skip:0 total:8
> > [    3.914685] # Totals: pass:8 fail:0 skip:0 total:8
> > [    3.915121] ok 1 kunit_executor_test
> > [    3.915736]     KTAP version 1
> > [    3.915949]     # Subtest: kunit-try-catch-test
> > [    3.916314]     # module: kunit_test
> > [    3.916315]     1..2
> > [    3.917655]     ok 1
> > kunit_test_try_catch_successful_try_no_catch
> > [    3.917979]     ok 2
> > kunit_test_try_catch_unsuccessful_try_does_catch
> > [    3.918630] # kunit-try-catch-test: pass:2 fail:0 skip:0 total:2
> > [    3.919118] # Totals: pass:2 fail:0 skip:0 total:2
> > [    3.919578] ok 2 kunit-try-catch-test
> > [    3.920248]     KTAP version 1
> > [    3.920473]     # Subtest: kunit-resource-test
> > [    3.920796]     # module: kunit_test
> > [    3.920797]     1..12
> > [    3.921565]     ok 1 kunit_resource_test_init_resources
> > [    3.921793]     ok 2 kunit_resource_test_alloc_resource
> > [    3.922449]     ok 3 kunit_resource_test_destroy_resource
> > [    3.923013]     ok 4 kunit_resource_test_remove_resource
> > [    3.924438]     ok 5 kunit_resource_test_cleanup_resources
> > [    3.925834]     ok 6 kunit_resource_test_proper_free_ordering
> > [    3.926700]     ok 7 kunit_resource_test_static
> > [    3.927588]     ok 8 kunit_resource_test_named
> > [    3.928244]     ok 9 kunit_resource_test_action
> > [    3.928774]     ok 10 kunit_resource_test_remove_action
> > [    3.929309]     ok 11 kunit_resource_test_release_action
> > [    3.929826] action_order_2
> > [    3.930325] action_order_2
> > [    3.930521] action_order_1
> > [    3.931007]     ok 12 kunit_resource_test_action_ordering
> > [    3.931308] # kunit-resource-test: pass:12 fail:0 skip:0
> > total:12
> > [    3.931702] # Totals: pass:12 fail:0 skip:0 total:12
> > [    3.932183] ok 3 kunit-resource-test
> > [    3.932809]     KTAP version 1
> > [    3.933040]     # Subtest: kunit-log-test
> > [    3.933367]     # module: kunit_test
> > [    3.933368]     1..2
> > [    3.934030] put this in log.
> > [    3.934033] this too.
> > [    3.934305] add to suite log.
> > [    3.934500] along with this.
> > [    3.934982]     ok 1 kunit_log_test
> > [    3.935405]     # kunit_log_newline_test: Add newline
> > [    3.936164]     ok 2 kunit_log_newline_test # SKIP only useful
> > when debugfs is enabled
> > [    3.936166] # kunit-log-test: pass:1 fail:0 skip:1 total:2
> > [    3.936752] # Totals: pass:1 fail:0 skip:1 total:2
> > [    3.937197] ok 4 kunit-log-test
> > [    3.937776]     KTAP version 1
> > [    3.938004]     # Subtest: kunit_status
> > [    3.938324]     # module: kunit_test
> > [    3.938325]     1..2
> > [    3.938921]     ok 1 kunit_status_set_failure_test
> > [    3.939049]     ok 2 kunit_status_mark_skipped_test
> > [    3.939445] # kunit_status: pass:2 fail:0 skip:0 total:2
> > [    3.939816] # Totals: pass:2 fail:0 skip:0 total:2
> > [    3.940436] ok 5 kunit_status
> > [    3.941142]     KTAP version 1
> > [    3.941508]     # Subtest: kunit_current
> > [    3.941793]     # module: kunit_test
> > [    3.941794]     1..2
> > [    3.942526]     ok 1 kunit_current_test
> > [    3.942596]     # fake test: lib/kunit/kunit-test.c:722: This
> > should make `fake` test fail.
> > [    3.943302]     ok 2 kunit_current_fail_test
> > [    3.943908] # kunit_current: pass:2 fail:0 skip:0 total:2
> > [    3.944271] # Totals: pass:2 fail:0 skip:0 total:2
> > [    3.944661] ok 6 kunit_current
> > [    3.945285]     KTAP version 1
> > [    3.945511]     # Subtest: kunit_device
> > [    3.945789]     # module: kunit_test
> > [    3.945790]     1..3
> > [    3.946905]     ok 1 kunit_device_test
> > [    3.947420]     ok 2 kunit_device_cleanup_test
> > [    3.948621]     ok 3 kunit_device_driver_test
> > [    3.948972] # kunit_device: pass:3 fail:0 skip:0 total:3
> > [    3.949349] # Totals: pass:3 fail:0 skip:0 total:3
> > [    3.949760] ok 7 kunit_device
> > [    3.950395]     KTAP version 1
> > [    3.950617]     # Subtest: kunit_fault
> > [    3.950889]     # module: kunit_test
> > [    3.950890]     1..1
> > [    3.951773] Oops: general protection fault, probably for non-
> > canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
> > PTI
> > [    3.952672] KASAN: null-ptr-deref in range [0x0000000000000000-
> > 0x0000000000000007]
> > [    3.953239] CPU: 2 UID: 0 PID: 225 Comm: kunit_try_catch
> > Tainted: G                 N 6.14.0-rc4-00388-g712b7c2f4d5d #21
> > [    3.954000] Tainted: [N]=TEST
> > [    3.954245] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.3-2.fc40 04/01/2014
> > [    3.954850] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
> > [    3.955285] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03
> > 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42
> > 04 01 f3 f3 f3 <0f> b6 04
> > [    3.956604] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
> > [    3.956972] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX:
> > ffffffffb65da11d
> > [    3.957651] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI:
> > ffff88810088fb30
> > [    3.958317] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09:
> > ffffed10207de600
> > [    3.958849] R10: ffff888103ef3007 R11: 0000000000000000 R12:
> > ffffffffb73baf40
> > [    3.959425] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15:
> > ffff8881091c6ac0
> > [    3.959917] FS:  0000000000000000(0000)
> > GS:ffff888a88700000(0000) knlGS:0000000000000000
> > [    3.960521] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [    3.960920] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4:
> > 00000000000006f0
> > [    3.961480] Call Trace:
> > [    3.961655]  <TASK>
> > [    3.961805]  ? die_addr+0x3b/0xa0
> > [    3.962052]  ? exc_general_protection+0x151/0x220
> > [    3.962439]  ? asm_exc_general_protection+0x26/0x30
> > [    3.962801]  ?
> > __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
> > [    3.963447]  ? __pfx_kunit_test_null_dereference+0x10/0x10
> > [    3.964150]  ? __kthread_parkme+0x7d/0x140
> > [    3.964443]  ? kunit_test_null_dereference+0x4a/0x150
> > [    3.964785]  ? __pfx_kunit_test_null_dereference+0x10/0x10
> > [    3.965205]  ? __kthread_parkme+0x7d/0x140
> > [    3.965494]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> > [    3.965859]  kthread+0x30f/0x620
> > [    3.966108]  ? __pfx_kthread+0x10/0x10
> > [    3.966406]  ? __pfx_kthread+0x10/0x10
> > [    3.966680]  ret_from_fork+0x2f/0x70
> > [    3.966941]  ? __pfx_kthread+0x10/0x10
> > [    3.967264]  ret_from_fork_asm+0x1a/0x30
> > [    3.967560]  </TASK>
> > [    3.967722] Modules linked in:
> > [    3.967989] ---[ end trace 0000000000000000 ]---
> > [    3.968368] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
> > [    3.968780] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03
> > 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42
> > 04 01 f3 f3 f3 <0f> b6 04
> > [    3.970211] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
> > [    3.970567] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX:
> > ffffffffb65da11d
> > [    3.971074] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI:
> > ffff88810088fb30
> > [    3.971580] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09:
> > ffffed10207de600
> > [    3.972089] R10: ffff888103ef3007 R11: 0000000000000000 R12:
> > ffffffffb73baf40
> > [    3.972629] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15:
> > ffff8881091c6ac0
> > [    3.973176] FS:  0000000000000000(0000)
> > GS:ffff888a88700000(0000) knlGS:0000000000000000
> > [    3.973720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [    3.974148] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4:
> > 00000000000006f0
> > [    3.974659] kunit_try_catch (225) used greatest stack depth:
> > 28416 bytes left
> > [    3.974764]     # kunit_test_fault_null_dereference: try
> > faulted: last line seen lib/kunit/kunit-test.c:95
> > [    3.976367]     ok 1 kunit_test_fault_null_dereference
> > [    3.976370] ok 8 kunit_fault
> > [    3.976946]     KTAP version 1
> > [    3.977208]     # Subtest: kunit_platform_device
> > [    3.977549]     # module: platform_test
> > [    3.977550]     1..4
> > [    3.978550]     ok 1 kunit_platform_device_alloc_test
> > [    3.978989]     ok 2 kunit_platform_device_add_test
> > [    3.980097] sysfs: cannot create duplicate filename
> > '/devices/platform/kunit-platform-add-2'
> > [    3.981138] CPU: 7 UID: 0 PID: 231 Comm: kunit_try_catch
> > Tainted: G      D          N 6.14.0-rc4-00388-g712b7c2f4d5d #21
> > [    3.981142] Tainted: [D]=DIE, [N]=TEST
> > [    3.981143] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.3-2.fc40 04/01/2014
> > [    3.981144] Call Trace:
> > [    3.981145]  <TASK>
> > [    3.981146]  dump_stack_lvl+0x53/0x70
> > [    3.981151]  sysfs_warn_dup+0x70/0x90
> > [    3.981154]  sysfs_create_dir_ns+0x209/0x280
> > [    3.981156]  ? __pfx_sysfs_create_dir_ns+0x10/0x10
> > [    3.981159]  ? _raw_spin_lock+0x80/0xe0
> > [    3.981161]  kobject_add_internal+0x216/0x8b0
> > [    3.981163]  kobject_add+0x13b/0x200
> > [    3.981165]  ? __pfx_kobject_add+0x10/0x10
> > [    3.981167]  ? kobject_get+0x50/0xe0
> > [    3.981169]  device_add+0x217/0x1460
> > [    3.981171]  ? __pfx_device_add+0x10/0x10
> > [    3.981173]  ? _raw_spin_lock_irqsave+0x86/0xe0
> > [    3.981174]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> > [    3.981176]  ? device_initialize+0x1f4/0x410
> > [    3.981179]  ? platform_device_alloc+0x97/0x200
> > [    3.981182]  platform_device_add+0x375/0x5b0
> > [    3.981184]  kunit_platform_device_add+0x20/0x2c0
> > [    3.981186] 
> > kunit_platform_device_add_twice_fails_test+0x1f5/0x420
> > [    3.981189]  ?
> > __pfx_kunit_platform_device_add_twice_fails_test+0x10/0x10
> > [    3.981191]  ? __schedule+0xdda/0x24f0
> > [    3.981193]  ? kvm_clock_get_cycles+0x18/0x30
> > [    3.981196]  ? ktime_get_ts64+0x7d/0x220
> > [    3.981200]  kunit_try_run_case+0x1ae/0x490
> > [    3.981202]  ? __pfx_kunit_try_run_case+0x10/0x10
> > [    3.981204]  ? _raw_spin_lock_irqsave+0x86/0xe0
> > [    3.981205]  ? __pfx_kunit_try_run_case+0x10/0x10
> > [    3.981207]  ?
> > __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
> > [    3.981210]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> > [    3.981212]  kthread+0x30f/0x620
> > [    3.981214]  ? __pfx_kthread+0x10/0x10
> > [    3.981216]  ? __pfx_kthread+0x10/0x10
> > [    3.981217]  ret_from_fork+0x2f/0x70
> > [    3.981223]  ? __pfx_kthread+0x10/0x10
> > [    3.981225]  ret_from_fork_asm+0x1a/0x30
> > [    3.981227]  </TASK>
> > [    3.981232] kobject: kobject_add_internal failed for kunit-
> > platform-add-2 with -EEXIST, don't try to register things with the
> > same name in the same direc.
> > [    3.995255] kunit_try_catch (231) used greatest stack depth:
> > 27528 bytes left
> > [    3.995525]     ok 3 kunit_platform_device_add_twice_fails_test
> > [    3.996247]     ok 4 kunit_platform_device_add_cleans_up
> > [    3.996678] # kunit_platform_device: pass:4 fail:0 skip:0
> > total:4
> > [    3.997073] # Totals: pass:4 fail:0 skip:0 total:4
> > [    3.997530] ok 9 kunit_platform_device
> > [    3.998130]     KTAP version 1
> > [    3.998356]     # Subtest: kunit_platform_driver
> > [    3.998664]     # module: platform_test
> > [    3.998665]     1..2
> > [    3.999663]     ok 1 kunit_platform_driver_register_test
> > [    4.000372]     ok 2
> > kunit_platform_device_prepare_wait_for_probe_completes_when_already
> > _probed
> > [    4.000750] # kunit_platform_driver: pass:2 fail:0 skip:0
> > total:2
> > [    4.001372] # Totals: pass:2 fail:0 skip:0 total:2
> > [    4.001777] ok 10 kunit_platform_driver
> > [    4.002412]     KTAP version 1
> > [    4.002618]     # Subtest: string-stream-test
> > [    4.002909]     # module: string_stream_test
> > [    4.002910]     1..12
> > [    4.003643]     ok 1 string_stream_managed_init_test
> > [    4.003919]     ok 2 string_stream_unmanaged_init_test
> > [    4.004581]     ok 3 string_stream_managed_free_test
> > [    4.005295]     ok 4 string_stream_resource_free_test
> > [    4.007076]     ok 5 string_stream_line_add_test
> > [    4.008801]     ok 6 string_stream_variable_length_line_test
> > [    4.009944]     ok 7 string_stream_append_test
> > [    4.010840]     ok 8 string_stream_append_auto_newline_test
> > [    4.011461]     ok 9 string_stream_append_empty_string_test
> > [    4.012233]     ok 10 string_stream_no_auto_newline_test
> > [    4.013158]     ok 11 string_stream_auto_newline_test
> > [    4.063760]     # string_stream_performance_test: Time
> > elapsed:           49385 us
> > [    4.064713]     # string_stream_performance_test: Total string
> > length:    573890
> > [    4.065271]     # string_stream_performance_test: Bytes
> > requested:        823930
> > [    4.065803]     # string_stream_performance_test: Actual bytes
> > allocated: 1048312
> > [    4.098820]     ok 12 string_stream_performance_test
> > [    4.098826] # string-stream-test: pass:12 fail:0 skip:0 total:12
> > [    4.099348] # Totals: pass:12 fail:0 skip:0 total:12
> > [    4.099814] ok 11 string-stream-test
> > [    4.100495]     KTAP version 1
> > [    4.100735]     # Subtest: kunit-assert
> > [    4.101048]     # module: assert_test
> > [    4.101050]     1..11
> > [    4.101943]     ok 1 kunit_test_is_literal
> > [    4.102331]     ok 2 kunit_test_is_str_literal
> > [    4.103177]     ok 3 kunit_test_assert_prologue
> > [    4.103996]     ok 4 kunit_test_assert_print_msg
> > [    4.104867]     ok 5 kunit_test_unary_assert_format
> > [    4.105908]     ok 6 kunit_test_ptr_not_err_assert_format
> > [    4.107022]     ok 7 kunit_test_binary_assert_format
> > [    4.107868]     ok 8 kunit_test_binary_ptr_assert_format
> > [    4.108702]     ok 9 kunit_test_binary_str_assert_format
> > [    4.109969]     ok 10 kunit_test_assert_hexdump
> > [    4.111490]     ok 11 kunit_test_mem_assert_format
> > [    4.111845] # kunit-assert: pass:11 fail:0 skip:0 total:11
> > [    4.112522] # Totals: pass:11 fail:0 skip:0 total:11
> > [    4.112949] ok 12 kunit-assert
> > [    4.113628]     KTAP version 1
> > [    4.113867]     # Subtest: drm_sched_basic_tests
> > [    4.114281]     # module: drm_sched_tests
> > [    4.114283]     1..3
> > [    4.234223] input: ImExPS/2 Generic Explorer Mouse as
> > /devices/platform/i8042/serio1/input/input3
> > [    4.617191]     ok 1 drm_sched_basic_submit
> > [    4.617197]         KTAP version 1
> > [    4.617765]         # Subtest: drm_sched_basic_test
> > [    4.719657]         ok 1 A queue of jobs in a single entity
> > [    4.821976]         ok 2 A chain of dependent jobs across
> > multiple entities
> > [    4.924015]         ok 3 Multiple independent job queues
> > [    5.026465]         ok 4 Multiple inter-dependent job queues
> > [    5.026907]     # drm_sched_basic_test: pass:4 fail:0 skip:0
> > total:4
> > [    5.027322]     ok 2 drm_sched_basic_test
> > [    5.080020]     ok 3 drm_sched_basic_entity_cleanup
> > [    5.080317] # drm_sched_basic_tests: pass:3 fail:0 skip:0
> > total:3
> > [    5.080657] # Totals: pass:6 fail:0 skip:0 total:6
> > [    5.081103] ok 13 drm_sched_basic_tests
> > [    5.081679]     KTAP version 1
> > [    5.081881]     # Subtest: drm_sched_basic_timeout_tests
> > [    5.082259]     # module: drm_sched_tests
> > [    5.082260]     1..1
> > 
> > 
> > 
> > > 
> > > Cc: Christian König <christian.koenig@amd.com>
> > > Cc: Danilo Krummrich <dakr@kernel.org>
> > > Cc: Matthew Brost <matthew.brost@intel.com>
> > > Cc: Philipp Stanner <phasta@kernel.org>
> > > 
> > > Tvrtko Ursulin (7):
> > >    drm: Move some options to separate new Kconfig
> > >    drm/sched: Add scheduler unit testing infrastructure and some
> > > basic
> > >      tests
> > >    drm/sched: Add aspirational unit test mode
> > >    drm/sched: Add a simple timeout test
> > >    drm/sched: Add basic priority tests
> > >    drm/sched: Add a basic test for modifying entities scheduler
> > > list
> > >    drm/sched: Add a basic test for checking credit limit
> > > 
> > >   drivers/gpu/drm/Kconfig                       | 109 +---
> > >   drivers/gpu/drm/Kconfig.debug                 | 128 +++++
> > >   drivers/gpu/drm/scheduler/.kunitconfig        |  12 +
> > >   drivers/gpu/drm/scheduler/Makefile            |   2 +
> > >   drivers/gpu/drm/scheduler/tests/Makefile      |   7 +
> > >   .../gpu/drm/scheduler/tests/mock_scheduler.c  | 345
> > > +++++++++++++
> > >   drivers/gpu/drm/scheduler/tests/sched_tests.h | 224 +++++++++
> > >   drivers/gpu/drm/scheduler/tests/tests_basic.c | 476
> > > ++++++++++++++++++
> > >   8 files changed, 1199 insertions(+), 104 deletions(-)
> > >   create mode 100644 drivers/gpu/drm/Kconfig.debug
> > >   create mode 100644 drivers/gpu/drm/scheduler/.kunitconfig
> > >   create mode 100644 drivers/gpu/drm/scheduler/tests/Makefile
> > >   create mode 100644
> > > drivers/gpu/drm/scheduler/tests/mock_scheduler.c
> > >   create mode 100644
> > > drivers/gpu/drm/scheduler/tests/sched_tests.h
> > >   create mode 100644
> > > drivers/gpu/drm/scheduler/tests/tests_basic.c
> > > 
> > 
>
Tvrtko Ursulin March 12, 2025, 1:27 p.m. UTC | #4
On 12/03/2025 12:35, Philipp Stanner wrote:
> On Wed, 2025-03-12 at 10:50 +0000, Tvrtko Ursulin wrote:
>>
>> On 12/03/2025 10:39, Philipp Stanner wrote:
>>> On Tue, 2025-03-11 at 09:23 +0000, Tvrtko Ursulin wrote:
>>>> There has repeatedly been quite a bit of apprehension when any
>>>> change
>>>> to the DRM
>>>> scheduler is proposed, with two main reasons being code base is
>>>> considered
>>>> fragile, not well understood and not very well documented, and
>>>> secondly the lack
>>>> of systematic testing outside the vendor specific tests suites
>>>> and/or
>>>> test
>>>> farms.
>>>>
>>>> This series is an attempt to dislodge this status quo by adding
>>>> some
>>>> unit tests
>>>> using the kunit framework.
>>>>
>>>> General approach is that there is a mock "hardware" backend which
>>>> can
>>>> be
>>>> controlled from tests, which in turn allows exercising various
>>>> scheduler code
>>>> paths.
>>>>
>>>> Only some simple basic tests get added in the series and
>>>> hopefully it
>>>> is easy to
>>>> understand what tests are doing.
>>>>
>>>> An obligatory "screenshot" for reference:
>>>>
>>>> [14:09:05] ============ drm_sched_basic_tests (3 subtests)
>>>> ============
>>>> [14:09:06] [PASSED] drm_sched_basic_submit
>>>> [14:09:06] ================== drm_sched_basic_test
>>>> ===================
>>>> [14:09:06] [PASSED] A queue of jobs in a single entity
>>>> [14:09:06] [PASSED] A chain of dependent jobs across multiple
>>>> entities
>>>> [14:09:06] [PASSED] Multiple independent job queues
>>>> [14:09:06] [PASSED] Multiple inter-dependent job queues
>>>> [14:09:07] ============== [PASSED] drm_sched_basic_test
>>>> ===============
>>>> [14:09:07] [PASSED] drm_sched_basic_entity_cleanup
>>>> [14:09:07] ============== [PASSED] drm_sched_basic_tests
>>>> ==============
>>>> [14:09:07] ======== drm_sched_basic_timeout_tests (1 subtest)
>>>> =========
>>>> [14:09:08] [PASSED] drm_sched_basic_timeout
>>>> [14:09:08] ========== [PASSED] drm_sched_basic_timeout_tests
>>>> ==========
>>>> [14:09:08] ======= drm_sched_basic_priority_tests (2 subtests)
>>>> ========
>>>> [14:09:10] [PASSED] drm_sched_priorities
>>>> [14:09:10] [PASSED] drm_sched_change_priority
>>>> [14:09:10] ========= [PASSED] drm_sched_basic_priority_tests
>>>> ==========
>>>> [14:09:10] ====== drm_sched_basic_modify_sched_tests (1 subtest)
>>>> ======
>>>> [14:09:11] [PASSED] drm_sched_test_modify_sched
>>>> [14:09:11] ======= [PASSED] drm_sched_basic_modify_sched_tests
>>>> ========
>>>> [14:09:11] ======== drm_sched_basic_credits_tests (1 subtest)
>>>> =========
>>>> [14:09:12] [PASSED] drm_sched_test_credits
>>>> [14:09:12] ========== [PASSED] drm_sched_basic_credits_tests
>>>> ==========
>>>> [14:09:12]
>>>> ============================================================
>>>> [14:09:12] Testing complete. Ran 11 tests: passed: 11
>>>> [14:09:13] Elapsed time: 13.539s total, 0.001s configuring,
>>>> 3.004s
>>>> building, 10.462s running
>>>>
>>>> v2:
>>>>    * Parameterize a bunch of similar tests.
>>>>    * Improve test commentary.
>>>>    * Rename TDR test to timeout. (Christian)
>>>>    * Improve quality and consistency of naming. (Philipp)
>>>>
>>>> RFC v2 -> series v1:
>>>>    * Rebased for drm_sched_init changes.
>>>>    * Fixed modular build.
>>>>    * Added some comments.
>>>>    * Filename renames. (Philipp)
>>>>
>>>> v2:
>>>>    * Dealt with a bunch of checkpatch warnings.
>>>>
>>>> v3:
>>>>    * Some mock API renames, kerneldoc grammar fixes and
>>>> indentation
>>>> fixes.
>>>>
>>>> v4:
>>>>    * Fix use after free caused by relying on scheduler fence for
>>>> querying status.
>>>>    * Kerneldoc fixes.
>>>>
>>>> v5:
>>>>    * Cleanup in-flight jobs on scheduler shutdown.
>>>>    * Change hang_limit to 1.
>>>>
>>>> v6:
>>>>    * Use KUNIT_ASSERT_TRUE/FALSE.
>>>>    * Fixed patch titles.
>>>>    * Added credit_limit test.
>>>
>>> Please don't add new tests in a settled series. Doing so may seem
>>> efficient, but causes another round of review and can cause you and
>>> me
>>> trouble when trying to find the cause of issues such as the one
>>> mentioned below:
>>>
>>>>    * Added CONFIG_DRM_SCHED_KUNIT_TEST_ASPIRATIONAL.
>>>>
>>>> v7:
>>>>    * v6 omitted to send the first patch by mistake.
>>>
>>> I either see a new NULL ptr deref added through the new test or an
>>> old
>>> one that has slipped us. My test setup is unchanged.
>>
>> All I see in what you pasted are kunit_test_null_dereference
>> "crashes".
>> Ie. expected ones from having enabled CONFIG_KUNIT_FAULT_TEST.
> 
> Allright, didn't know about that. Help me out here quickly, so would
> this option lead to a real fault on a real CPU? Or is it "simulated"?

AFAIU it is real faults where kunit test framework is testing itself 
whether it can catch them.

>> Is there something more that you did not paste?
> 
> No, that was all.
> 
> I tried it again without the KUNIT_FAULT option and activated
> aspirational mode. (on top of current drm-misc-next, eff0347e7c22).
> 
> There I see a UAF. Do you have an idea what that might be? I would only
> expect memory leaks and the test assertions failing.

It is expected all hell to break loose in aspirational mode. There the 
mock scheduler shutdown relies solely on drm_sched_fini. So all tests 
which do not fully idle the mock scheduler themselves, whether implicity 
or explicitly, will explode in various ways.

Regards,

Tvrtko

> [    3.976637] Demotion targets for Node 0: null
> [    3.977265] kmemleak: Kernel memory leak detector initialized (mem pool available: 11277)
> [    3.977274] kmemleak: Automatic memory scanning thread started
> [    3.978604] PM:   Magic number: 1:529:430
> [    3.978914] printk: legacy console [netcon0] enabled
> [    3.979247] netconsole: network logging started
> [    3.979839] cfg80211: Loading compiled-in X.509 certificates for regulatory database
> [    3.980811] kworker/u72:1 (156) used greatest stack depth: 28552 bytes left
> [    3.981632] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
> [    3.982437] Loaded X.509 cert 'wens: 61c038651aabdcf94bd0ac7ff06c7248db18c600'
> [    3.983110] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
> [    3.983578] KTAP version 1
> [    3.983767] cfg80211: failed to load regulatory.db
> [    3.983988] 1..5
> [    3.984976]     KTAP version 1
> [    3.985299]     # Subtest: drm_sched_basic_tests
> [    3.985681]     # module: drm_sched_tests
> [    3.985683]     1..3
> [    4.319827] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input3
> [    4.495862]     ok 1 drm_sched_basic_submit
> [    4.495879]         KTAP version 1
> [    4.496468]         # Subtest: drm_sched_basic_test
> [    4.598388]         ok 1 A queue of jobs in a single entity
> [    4.700730]         ok 2 A chain of dependent jobs across multiple entities
> [    4.803439]         ok 3 Multiple independent job queues
> [    4.905560]         ok 4 Multiple inter-dependent job queues
> [    4.906029]     # drm_sched_basic_test: pass:4 fail:0 skip:0 total:4
> [    4.906500]     ok 2 drm_sched_basic_test
> [    4.959366]     # drm_sched_basic_entity_cleanup: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
> [    4.959366]     Expected list_empty(&sched->job_list) to be true, but is false
> [    4.961263]     # drm_sched_basic_entity_cleanup: test aborted during cleanup. continuing without cleaning up
> [    4.961997]     not ok 3 drm_sched_basic_entity_cleanup
> [    4.961999] # drm_sched_basic_tests: pass:2 fail:1 skip:0 total:3
> [    4.962384] # Totals: pass:5 fail:1 skip:0 total:6
> [    4.962823] not ok 1 drm_sched_basic_tests
> [    4.963465]     KTAP version 1
> [    4.963691]     # Subtest: drm_sched_basic_timeout_tests
> [    4.964065]     # module: drm_sched_tests
> [    4.964067]     1..1
> [    6.503265]     # drm_sched_basic_timeout: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
> [    6.503265]     Expected list_empty(&sched->job_list) to be true, but is false
> [    6.504778]     # drm_sched_basic_timeout: test aborted during cleanup. continuing without cleaning up
> [    6.505457]     not ok 1 drm_sched_basic_timeout
> [    6.505460] not ok 2 drm_sched_basic_timeout_tests
> [    6.506128]     KTAP version 1
> [    6.506360]     # Subtest: drm_sched_basic_priority_tests
> [    6.506751]     # module: drm_sched_tests
> [    6.506753]     1..2
> [    6.609082]     ok 1 drm_sched_priorities
> [    7.614297]     ok 2 drm_sched_change_priority
> [    7.614723] # drm_sched_basic_priority_tests: pass:2 fail:0 skip:0 total:2
> [    7.615130] # Totals: pass:2 fail:0 skip:0 total:2
> [    7.615667] ok 3 drm_sched_basic_priority_tests
> [    7.616344]     KTAP version 1
> [    7.616580]     # Subtest: drm_sched_basic_modify_sched_tests
> [    7.617039]     # module: drm_sched_tests
> [    7.617042]     1..1
> [    7.926594]     # drm_sched_test_modify_sched: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
> [    7.926594]     Expected list_empty(&sched->job_list) to be true, but is false
> [    7.928533] ==================================================================
> [    7.929065] BUG: KASAN: slab-use-after-free in timerqueue_add+0x24e/0x320
> [    7.929596] Read of size 8 at addr ffff8881092ec8e8 by task swapper/5/0
> [    7.930092]
> [    7.930251] CPU: 5 UID: 0 PID: 0 Comm: swapper/5 Tainted: G                 N 6.14.0-rc4-00476-ge1aa9011309e #6
> [    7.930256] Tainted: [N]=TEST
> [    7.930257] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
> [    7.930258] Call Trace:
> [    7.930260]  <IRQ>
> [    7.930261]  dump_stack_lvl+0x53/0x70
> [    7.930265]  print_report+0xce/0x680
> [    7.930269]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> [    7.930271]  ? __pfx_calc_global_load_tick+0x10/0x10
> [    7.930274]  ? timerqueue_add+0x24e/0x320
> [    7.930276]  kasan_report+0xe2/0x120
> [    7.930278]  ? timerqueue_add+0x24e/0x320
> [    7.930280]  timerqueue_add+0x24e/0x320
> [    7.930281]  __hrtimer_run_queues+0x358/0x6f0
> [    7.930284]  ? __pfx___hrtimer_run_queues+0x10/0x10
> [    7.930286]  ? ktime_get_update_offsets_now+0x7c/0x2c0
> [    7.930288]  hrtimer_interrupt+0x2cd/0x7e0
> [    7.930290]  __sysvec_apic_timer_interrupt+0x88/0x260
> [    7.930293]  sysvec_apic_timer_interrupt+0x67/0x80
> [    7.930295]  </IRQ>
> [    7.930296]  <TASK>
> [    7.930296]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
> [    7.930299] RIP: 0010:default_idle+0xf/0x20
> [    7.930302] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d b3 d6 06 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
> [    7.930304] RSP: 0000:ffff888100b8fe70 EFLAGS: 00000206
> [    7.930306] RAX: ffff888a8ec80000 RBX: 0000000000000005 RCX: ffffffffbb3b7c41
> [    7.930308] RDX: ffffed1151d96a83 RSI: 0000000000000004 RDI: 0000000000036334
> [    7.930309] RBP: ffffed1020161d58 R08: 0000000000000001 R09: ffffed1151d96a82
> [    7.930309] R10: ffff888a8ecb5413 R11: 0000000000001400 R12: ffff888100b0eac0
> [    7.930310] R13: ffffffffbc7f36d0 R14: 1ffff11020171fd2 R15: 0000000000000000
> [    7.930312]  ? ct_kernel_exit.constprop.0+0xa1/0xc0
> [    7.930314]  default_idle_call+0x3a/0x60
> [    7.930316]  do_idle+0x2f2/0x3b0
> [    7.930318]  ? __pfx_do_idle+0x10/0x10
> [    7.930320]  ? __switch_to+0x5cd/0xe30
> [    7.930323]  cpu_startup_entry+0x4f/0x60
> [    7.930324]  start_secondary+0x1b7/0x210
> [    7.930326]  common_startup_64+0x12c/0x138
> [    7.930328]  </TASK>
> [    7.930329]
> [    7.931848]     not ok 1 drm_sched_test_modify_sched
> [    7.932019] Allocated by task 187:
> [    7.932285] not ok 4 drm_sched_basic_modify_sched_tests
> [    7.932486]  kasan_save_stack+0x33/0x60
> [    7.932835]     KTAP version 1
> [    7.933153]  kasan_save_track+0x14/0x30
> [    7.933156]  __kasan_kmalloc+0x8f/0xa0
> [    7.933652]     # Subtest: drm_sched_basic_credits_tests
> [    7.934095]  __kmalloc_noprof+0x18a/0x440
> [    7.934494]     # module: drm_sched_tests
> [    7.934817]  kunit_kmalloc_array+0x1b/0x50
> [    7.935201]     1..1
> [    7.935589]  drm_mock_sched_job_new+0x8f/0x400
> [    7.935592]  drm_sched_test_modify_sched+0x1cd/0x490
> [    7.950666]  kunit_try_run_case+0x1ae/0x490
> [    7.950977]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> [    7.951400]  kthread+0x30f/0x620
> [    7.951656]  ret_from_fork+0x2f/0x70
> [    7.951936]  ret_from_fork_asm+0x1a/0x30
> [    7.952250]
> [    7.952373] Freed by task 192:
> [    7.952605]  kasan_save_stack+0x33/0x60
> [    7.952884]  kasan_save_track+0x14/0x30
> [    7.953169]  kasan_save_free_info+0x3b/0x60
> [    7.953495]  __kasan_slab_free+0x37/0x50
> [    7.953797]  kfree+0x12f/0x350
> [    7.954035]  kunit_remove_resource+0x130/0x1f0
> [    7.954379]  kunit_cleanup+0x6e/0x110
> [    7.954656]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> [    7.955044]  kthread+0x30f/0x620
> [    7.955286]  ret_from_fork+0x2f/0x70
> [    7.955557]  ret_from_fork_asm+0x1a/0x30
> [    7.955844]
> [    7.955956] The buggy address belongs to the object at ffff8881092ec800
> [    7.955956]  which belongs to the cache kmalloc-512 of size 512
> [    7.956883] The buggy address is located 232 bytes inside of
> [    7.956883]  freed 512-byte region [ffff8881092ec800, ffff8881092eca00)
> [    7.957790]
> [    7.957904] The buggy address belongs to the physical page:
> [    7.958324] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1092e8
> [    7.958925] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> [    7.959527] flags: 0x200000000000040(head|node=0|zone=2)
> [    7.959926] page_type: f5(slab)
> [    7.960163] raw: 0200000000000040 ffff888100042c80 dead000000000122 0000000000000000
> [    7.960743] raw: 0000000000000000 0000000080200020 00000000f5000000 0000000000000000
> [    7.961304] head: 0200000000000040 ffff888100042c80 dead000000000122 0000000000000000
> [    7.961880] head: 0000000000000000 0000000080200020 00000000f5000000 0000000000000000
> [    7.962460] head: 0200000000000003 ffffea000424ba01 ffffffffffffffff 0000000000000000
> [    7.963025] head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
> [    7.963602] page dumped because: kasan: bad access detected
> [    7.964001]
> [    7.964113] Memory state around the buggy address:
> [    7.964481]  ffff8881092ec780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [    7.965007]  ffff8881092ec800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [    7.965576] >ffff8881092ec880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [    7.966120]                                                           ^
> [    7.966625]  ffff8881092ec900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [    7.967199]  ffff8881092ec980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> [    7.967734] ==================================================================
> [    7.968267] Disabling lock debugging due to kernel taint
> [    8.999147]     # drm_sched_test_credits: ASSERTION FAILED at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:295
> [    8.999147]     Expected list_empty(&sched->base.pending_list) to be true, but is false
> [    9.001031]     not ok 1 drm_sched_test_credits
> [    9.001034] not ok 5 drm_sched_basic_credits_tests
> 
> 
> 
>>
>>> On which commit do you apply and test this series? Tell me, then I
>>> test again.
>>
>> Depending on the setup, these three:
>>
>> commit 413ae464b8021542ad90cb1fbb15f8efc5050a5d
>> Author: Thomas Zimmermann <tzimmermann@suse.de>
>> Date:   Mon Mar 3 16:41:48 2025 +0100
>>
>>       drm-tip: 2025y-03m-03d-15h-40m-53s UTC integration manifest
>>
>> commit 5bcb67a2a4c61034f5a25c024631c5fbf351ee8d
>> Author: Matt Coster <matt.coster@imgtec.com>
>> Date:   Wed Feb 26 10:01:09 2025 +0000
>>
>>       drm-tip: 2025y-02m-26d-09h-59m-48s UTC integration manifest
>>
>> commit 777e1850811f9864aa8b55940634d3da19712bf7
>> Author: Imre Deak <imre.deak@intel.com>
>> Date:   Tue Mar 11 11:31:04 2025 +0200
>>
>>       drm-tip: 2025y-03m-11d-09h-30m-13s UTC integration manifest
>>
>> Regards,
>>
>> Tvrtko
>>
>>> [    3.902457] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
>>> [    3.903376] Loaded X.509 cert 'wens:
>>> 61c038651aabdcf94bd0ac7ff06c7248db18c600'
>>> [    3.904064] platform regulatory.0: Direct firmware load for
>>> regulatory.db failed with error -2
>>> [    3.904673] cfg80211: failed to load regulatory.db
>>> [    3.905037] ALSA device list:
>>> [    3.905376]   No soundcards found.
>>> [    3.905631] KTAP version 1
>>> [    3.905834] 1..17
>>> [    3.906732]     KTAP version 1
>>> [    3.906999]     # Subtest: kunit_executor_test
>>> [    3.907335]     # module: kunit
>>> [    3.907337]     1..8
>>> [    3.908476]     ok 1 parse_filter_test
>>> [    3.909064]     ok 2 filter_suites_test
>>> [    3.909801]     ok 3 filter_suites_test_glob_test
>>> [    3.910678]     ok 4 filter_suites_to_empty_test
>>> [    3.911621]     ok 5 parse_filter_attr_test
>>> [    3.912641]     ok 6 filter_attr_test
>>> [    3.913511]     ok 7 filter_attr_empty_test
>>> [    3.914081]     ok 8 filter_attr_skip_test
>>> [    3.914400] # kunit_executor_test: pass:8 fail:0 skip:0 total:8
>>> [    3.914685] # Totals: pass:8 fail:0 skip:0 total:8
>>> [    3.915121] ok 1 kunit_executor_test
>>> [    3.915736]     KTAP version 1
>>> [    3.915949]     # Subtest: kunit-try-catch-test
>>> [    3.916314]     # module: kunit_test
>>> [    3.916315]     1..2
>>> [    3.917655]     ok 1
>>> kunit_test_try_catch_successful_try_no_catch
>>> [    3.917979]     ok 2
>>> kunit_test_try_catch_unsuccessful_try_does_catch
>>> [    3.918630] # kunit-try-catch-test: pass:2 fail:0 skip:0 total:2
>>> [    3.919118] # Totals: pass:2 fail:0 skip:0 total:2
>>> [    3.919578] ok 2 kunit-try-catch-test
>>> [    3.920248]     KTAP version 1
>>> [    3.920473]     # Subtest: kunit-resource-test
>>> [    3.920796]     # module: kunit_test
>>> [    3.920797]     1..12
>>> [    3.921565]     ok 1 kunit_resource_test_init_resources
>>> [    3.921793]     ok 2 kunit_resource_test_alloc_resource
>>> [    3.922449]     ok 3 kunit_resource_test_destroy_resource
>>> [    3.923013]     ok 4 kunit_resource_test_remove_resource
>>> [    3.924438]     ok 5 kunit_resource_test_cleanup_resources
>>> [    3.925834]     ok 6 kunit_resource_test_proper_free_ordering
>>> [    3.926700]     ok 7 kunit_resource_test_static
>>> [    3.927588]     ok 8 kunit_resource_test_named
>>> [    3.928244]     ok 9 kunit_resource_test_action
>>> [    3.928774]     ok 10 kunit_resource_test_remove_action
>>> [    3.929309]     ok 11 kunit_resource_test_release_action
>>> [    3.929826] action_order_2
>>> [    3.930325] action_order_2
>>> [    3.930521] action_order_1
>>> [    3.931007]     ok 12 kunit_resource_test_action_ordering
>>> [    3.931308] # kunit-resource-test: pass:12 fail:0 skip:0
>>> total:12
>>> [    3.931702] # Totals: pass:12 fail:0 skip:0 total:12
>>> [    3.932183] ok 3 kunit-resource-test
>>> [    3.932809]     KTAP version 1
>>> [    3.933040]     # Subtest: kunit-log-test
>>> [    3.933367]     # module: kunit_test
>>> [    3.933368]     1..2
>>> [    3.934030] put this in log.
>>> [    3.934033] this too.
>>> [    3.934305] add to suite log.
>>> [    3.934500] along with this.
>>> [    3.934982]     ok 1 kunit_log_test
>>> [    3.935405]     # kunit_log_newline_test: Add newline
>>> [    3.936164]     ok 2 kunit_log_newline_test # SKIP only useful
>>> when debugfs is enabled
>>> [    3.936166] # kunit-log-test: pass:1 fail:0 skip:1 total:2
>>> [    3.936752] # Totals: pass:1 fail:0 skip:1 total:2
>>> [    3.937197] ok 4 kunit-log-test
>>> [    3.937776]     KTAP version 1
>>> [    3.938004]     # Subtest: kunit_status
>>> [    3.938324]     # module: kunit_test
>>> [    3.938325]     1..2
>>> [    3.938921]     ok 1 kunit_status_set_failure_test
>>> [    3.939049]     ok 2 kunit_status_mark_skipped_test
>>> [    3.939445] # kunit_status: pass:2 fail:0 skip:0 total:2
>>> [    3.939816] # Totals: pass:2 fail:0 skip:0 total:2
>>> [    3.940436] ok 5 kunit_status
>>> [    3.941142]     KTAP version 1
>>> [    3.941508]     # Subtest: kunit_current
>>> [    3.941793]     # module: kunit_test
>>> [    3.941794]     1..2
>>> [    3.942526]     ok 1 kunit_current_test
>>> [    3.942596]     # fake test: lib/kunit/kunit-test.c:722: This
>>> should make `fake` test fail.
>>> [    3.943302]     ok 2 kunit_current_fail_test
>>> [    3.943908] # kunit_current: pass:2 fail:0 skip:0 total:2
>>> [    3.944271] # Totals: pass:2 fail:0 skip:0 total:2
>>> [    3.944661] ok 6 kunit_current
>>> [    3.945285]     KTAP version 1
>>> [    3.945511]     # Subtest: kunit_device
>>> [    3.945789]     # module: kunit_test
>>> [    3.945790]     1..3
>>> [    3.946905]     ok 1 kunit_device_test
>>> [    3.947420]     ok 2 kunit_device_cleanup_test
>>> [    3.948621]     ok 3 kunit_device_driver_test
>>> [    3.948972] # kunit_device: pass:3 fail:0 skip:0 total:3
>>> [    3.949349] # Totals: pass:3 fail:0 skip:0 total:3
>>> [    3.949760] ok 7 kunit_device
>>> [    3.950395]     KTAP version 1
>>> [    3.950617]     # Subtest: kunit_fault
>>> [    3.950889]     # module: kunit_test
>>> [    3.950890]     1..1
>>> [    3.951773] Oops: general protection fault, probably for non-
>>> canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
>>> PTI
>>> [    3.952672] KASAN: null-ptr-deref in range [0x0000000000000000-
>>> 0x0000000000000007]
>>> [    3.953239] CPU: 2 UID: 0 PID: 225 Comm: kunit_try_catch
>>> Tainted: G                 N 6.14.0-rc4-00388-g712b7c2f4d5d #21
>>> [    3.954000] Tainted: [N]=TEST
>>> [    3.954245] Hardware name: QEMU Standard PC (i440FX + PIIX,
>>> 1996), BIOS 1.16.3-2.fc40 04/01/2014
>>> [    3.954850] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
>>> [    3.955285] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03
>>> 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42
>>> 04 01 f3 f3 f3 <0f> b6 04
>>> [    3.956604] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
>>> [    3.956972] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX:
>>> ffffffffb65da11d
>>> [    3.957651] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI:
>>> ffff88810088fb30
>>> [    3.958317] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09:
>>> ffffed10207de600
>>> [    3.958849] R10: ffff888103ef3007 R11: 0000000000000000 R12:
>>> ffffffffb73baf40
>>> [    3.959425] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15:
>>> ffff8881091c6ac0
>>> [    3.959917] FS:  0000000000000000(0000)
>>> GS:ffff888a88700000(0000) knlGS:0000000000000000
>>> [    3.960521] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [    3.960920] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4:
>>> 00000000000006f0
>>> [    3.961480] Call Trace:
>>> [    3.961655]  <TASK>
>>> [    3.961805]  ? die_addr+0x3b/0xa0
>>> [    3.962052]  ? exc_general_protection+0x151/0x220
>>> [    3.962439]  ? asm_exc_general_protection+0x26/0x30
>>> [    3.962801]  ?
>>> __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
>>> [    3.963447]  ? __pfx_kunit_test_null_dereference+0x10/0x10
>>> [    3.964150]  ? __kthread_parkme+0x7d/0x140
>>> [    3.964443]  ? kunit_test_null_dereference+0x4a/0x150
>>> [    3.964785]  ? __pfx_kunit_test_null_dereference+0x10/0x10
>>> [    3.965205]  ? __kthread_parkme+0x7d/0x140
>>> [    3.965494]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
>>> [    3.965859]  kthread+0x30f/0x620
>>> [    3.966108]  ? __pfx_kthread+0x10/0x10
>>> [    3.966406]  ? __pfx_kthread+0x10/0x10
>>> [    3.966680]  ret_from_fork+0x2f/0x70
>>> [    3.966941]  ? __pfx_kthread+0x10/0x10
>>> [    3.967264]  ret_from_fork_asm+0x1a/0x30
>>> [    3.967560]  </TASK>
>>> [    3.967722] Modules linked in:
>>> [    3.967989] ---[ end trace 0000000000000000 ]---
>>> [    3.968368] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
>>> [    3.968780] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03
>>> 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42
>>> 04 01 f3 f3 f3 <0f> b6 04
>>> [    3.970211] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
>>> [    3.970567] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX:
>>> ffffffffb65da11d
>>> [    3.971074] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI:
>>> ffff88810088fb30
>>> [    3.971580] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09:
>>> ffffed10207de600
>>> [    3.972089] R10: ffff888103ef3007 R11: 0000000000000000 R12:
>>> ffffffffb73baf40
>>> [    3.972629] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15:
>>> ffff8881091c6ac0
>>> [    3.973176] FS:  0000000000000000(0000)
>>> GS:ffff888a88700000(0000) knlGS:0000000000000000
>>> [    3.973720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [    3.974148] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4:
>>> 00000000000006f0
>>> [    3.974659] kunit_try_catch (225) used greatest stack depth:
>>> 28416 bytes left
>>> [    3.974764]     # kunit_test_fault_null_dereference: try
>>> faulted: last line seen lib/kunit/kunit-test.c:95
>>> [    3.976367]     ok 1 kunit_test_fault_null_dereference
>>> [    3.976370] ok 8 kunit_fault
>>> [    3.976946]     KTAP version 1
>>> [    3.977208]     # Subtest: kunit_platform_device
>>> [    3.977549]     # module: platform_test
>>> [    3.977550]     1..4
>>> [    3.978550]     ok 1 kunit_platform_device_alloc_test
>>> [    3.978989]     ok 2 kunit_platform_device_add_test
>>> [    3.980097] sysfs: cannot create duplicate filename
>>> '/devices/platform/kunit-platform-add-2'
>>> [    3.981138] CPU: 7 UID: 0 PID: 231 Comm: kunit_try_catch
>>> Tainted: G      D          N 6.14.0-rc4-00388-g712b7c2f4d5d #21
>>> [    3.981142] Tainted: [D]=DIE, [N]=TEST
>>> [    3.981143] Hardware name: QEMU Standard PC (i440FX + PIIX,
>>> 1996), BIOS 1.16.3-2.fc40 04/01/2014
>>> [    3.981144] Call Trace:
>>> [    3.981145]  <TASK>
>>> [    3.981146]  dump_stack_lvl+0x53/0x70
>>> [    3.981151]  sysfs_warn_dup+0x70/0x90
>>> [    3.981154]  sysfs_create_dir_ns+0x209/0x280
>>> [    3.981156]  ? __pfx_sysfs_create_dir_ns+0x10/0x10
>>> [    3.981159]  ? _raw_spin_lock+0x80/0xe0
>>> [    3.981161]  kobject_add_internal+0x216/0x8b0
>>> [    3.981163]  kobject_add+0x13b/0x200
>>> [    3.981165]  ? __pfx_kobject_add+0x10/0x10
>>> [    3.981167]  ? kobject_get+0x50/0xe0
>>> [    3.981169]  device_add+0x217/0x1460
>>> [    3.981171]  ? __pfx_device_add+0x10/0x10
>>> [    3.981173]  ? _raw_spin_lock_irqsave+0x86/0xe0
>>> [    3.981174]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
>>> [    3.981176]  ? device_initialize+0x1f4/0x410
>>> [    3.981179]  ? platform_device_alloc+0x97/0x200
>>> [    3.981182]  platform_device_add+0x375/0x5b0
>>> [    3.981184]  kunit_platform_device_add+0x20/0x2c0
>>> [    3.981186]
>>> kunit_platform_device_add_twice_fails_test+0x1f5/0x420
>>> [    3.981189]  ?
>>> __pfx_kunit_platform_device_add_twice_fails_test+0x10/0x10
>>> [    3.981191]  ? __schedule+0xdda/0x24f0
>>> [    3.981193]  ? kvm_clock_get_cycles+0x18/0x30
>>> [    3.981196]  ? ktime_get_ts64+0x7d/0x220
>>> [    3.981200]  kunit_try_run_case+0x1ae/0x490
>>> [    3.981202]  ? __pfx_kunit_try_run_case+0x10/0x10
>>> [    3.981204]  ? _raw_spin_lock_irqsave+0x86/0xe0
>>> [    3.981205]  ? __pfx_kunit_try_run_case+0x10/0x10
>>> [    3.981207]  ?
>>> __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
>>> [    3.981210]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
>>> [    3.981212]  kthread+0x30f/0x620
>>> [    3.981214]  ? __pfx_kthread+0x10/0x10
>>> [    3.981216]  ? __pfx_kthread+0x10/0x10
>>> [    3.981217]  ret_from_fork+0x2f/0x70
>>> [    3.981223]  ? __pfx_kthread+0x10/0x10
>>> [    3.981225]  ret_from_fork_asm+0x1a/0x30
>>> [    3.981227]  </TASK>
>>> [    3.981232] kobject: kobject_add_internal failed for kunit-
>>> platform-add-2 with -EEXIST, don't try to register things with the
>>> same name in the same direc.
>>> [    3.995255] kunit_try_catch (231) used greatest stack depth:
>>> 27528 bytes left
>>> [    3.995525]     ok 3 kunit_platform_device_add_twice_fails_test
>>> [    3.996247]     ok 4 kunit_platform_device_add_cleans_up
>>> [    3.996678] # kunit_platform_device: pass:4 fail:0 skip:0
>>> total:4
>>> [    3.997073] # Totals: pass:4 fail:0 skip:0 total:4
>>> [    3.997530] ok 9 kunit_platform_device
>>> [    3.998130]     KTAP version 1
>>> [    3.998356]     # Subtest: kunit_platform_driver
>>> [    3.998664]     # module: platform_test
>>> [    3.998665]     1..2
>>> [    3.999663]     ok 1 kunit_platform_driver_register_test
>>> [    4.000372]     ok 2
>>> kunit_platform_device_prepare_wait_for_probe_completes_when_already
>>> _probed
>>> [    4.000750] # kunit_platform_driver: pass:2 fail:0 skip:0
>>> total:2
>>> [    4.001372] # Totals: pass:2 fail:0 skip:0 total:2
>>> [    4.001777] ok 10 kunit_platform_driver
>>> [    4.002412]     KTAP version 1
>>> [    4.002618]     # Subtest: string-stream-test
>>> [    4.002909]     # module: string_stream_test
>>> [    4.002910]     1..12
>>> [    4.003643]     ok 1 string_stream_managed_init_test
>>> [    4.003919]     ok 2 string_stream_unmanaged_init_test
>>> [    4.004581]     ok 3 string_stream_managed_free_test
>>> [    4.005295]     ok 4 string_stream_resource_free_test
>>> [    4.007076]     ok 5 string_stream_line_add_test
>>> [    4.008801]     ok 6 string_stream_variable_length_line_test
>>> [    4.009944]     ok 7 string_stream_append_test
>>> [    4.010840]     ok 8 string_stream_append_auto_newline_test
>>> [    4.011461]     ok 9 string_stream_append_empty_string_test
>>> [    4.012233]     ok 10 string_stream_no_auto_newline_test
>>> [    4.013158]     ok 11 string_stream_auto_newline_test
>>> [    4.063760]     # string_stream_performance_test: Time
>>> elapsed:           49385 us
>>> [    4.064713]     # string_stream_performance_test: Total string
>>> length:    573890
>>> [    4.065271]     # string_stream_performance_test: Bytes
>>> requested:        823930
>>> [    4.065803]     # string_stream_performance_test: Actual bytes
>>> allocated: 1048312
>>> [    4.098820]     ok 12 string_stream_performance_test
>>> [    4.098826] # string-stream-test: pass:12 fail:0 skip:0 total:12
>>> [    4.099348] # Totals: pass:12 fail:0 skip:0 total:12
>>> [    4.099814] ok 11 string-stream-test
>>> [    4.100495]     KTAP version 1
>>> [    4.100735]     # Subtest: kunit-assert
>>> [    4.101048]     # module: assert_test
>>> [    4.101050]     1..11
>>> [    4.101943]     ok 1 kunit_test_is_literal
>>> [    4.102331]     ok 2 kunit_test_is_str_literal
>>> [    4.103177]     ok 3 kunit_test_assert_prologue
>>> [    4.103996]     ok 4 kunit_test_assert_print_msg
>>> [    4.104867]     ok 5 kunit_test_unary_assert_format
>>> [    4.105908]     ok 6 kunit_test_ptr_not_err_assert_format
>>> [    4.107022]     ok 7 kunit_test_binary_assert_format
>>> [    4.107868]     ok 8 kunit_test_binary_ptr_assert_format
>>> [    4.108702]     ok 9 kunit_test_binary_str_assert_format
>>> [    4.109969]     ok 10 kunit_test_assert_hexdump
>>> [    4.111490]     ok 11 kunit_test_mem_assert_format
>>> [    4.111845] # kunit-assert: pass:11 fail:0 skip:0 total:11
>>> [    4.112522] # Totals: pass:11 fail:0 skip:0 total:11
>>> [    4.112949] ok 12 kunit-assert
>>> [    4.113628]     KTAP version 1
>>> [    4.113867]     # Subtest: drm_sched_basic_tests
>>> [    4.114281]     # module: drm_sched_tests
>>> [    4.114283]     1..3
>>> [    4.234223] input: ImExPS/2 Generic Explorer Mouse as
>>> /devices/platform/i8042/serio1/input/input3
>>> [    4.617191]     ok 1 drm_sched_basic_submit
>>> [    4.617197]         KTAP version 1
>>> [    4.617765]         # Subtest: drm_sched_basic_test
>>> [    4.719657]         ok 1 A queue of jobs in a single entity
>>> [    4.821976]         ok 2 A chain of dependent jobs across
>>> multiple entities
>>> [    4.924015]         ok 3 Multiple independent job queues
>>> [    5.026465]         ok 4 Multiple inter-dependent job queues
>>> [    5.026907]     # drm_sched_basic_test: pass:4 fail:0 skip:0
>>> total:4
>>> [    5.027322]     ok 2 drm_sched_basic_test
>>> [    5.080020]     ok 3 drm_sched_basic_entity_cleanup
>>> [    5.080317] # drm_sched_basic_tests: pass:3 fail:0 skip:0
>>> total:3
>>> [    5.080657] # Totals: pass:6 fail:0 skip:0 total:6
>>> [    5.081103] ok 13 drm_sched_basic_tests
>>> [    5.081679]     KTAP version 1
>>> [    5.081881]     # Subtest: drm_sched_basic_timeout_tests
>>> [    5.082259]     # module: drm_sched_tests
>>> [    5.082260]     1..1
>>>
>>>
>>>
>>>>
>>>> Cc: Christian König <christian.koenig@amd.com>
>>>> Cc: Danilo Krummrich <dakr@kernel.org>
>>>> Cc: Matthew Brost <matthew.brost@intel.com>
>>>> Cc: Philipp Stanner <phasta@kernel.org>
>>>>
>>>> Tvrtko Ursulin (7):
>>>>     drm: Move some options to separate new Kconfig
>>>>     drm/sched: Add scheduler unit testing infrastructure and some
>>>> basic
>>>>       tests
>>>>     drm/sched: Add aspirational unit test mode
>>>>     drm/sched: Add a simple timeout test
>>>>     drm/sched: Add basic priority tests
>>>>     drm/sched: Add a basic test for modifying entities scheduler
>>>> list
>>>>     drm/sched: Add a basic test for checking credit limit
>>>>
>>>>    drivers/gpu/drm/Kconfig                       | 109 +---
>>>>    drivers/gpu/drm/Kconfig.debug                 | 128 +++++
>>>>    drivers/gpu/drm/scheduler/.kunitconfig        |  12 +
>>>>    drivers/gpu/drm/scheduler/Makefile            |   2 +
>>>>    drivers/gpu/drm/scheduler/tests/Makefile      |   7 +
>>>>    .../gpu/drm/scheduler/tests/mock_scheduler.c  | 345
>>>> +++++++++++++
>>>>    drivers/gpu/drm/scheduler/tests/sched_tests.h | 224 +++++++++
>>>>    drivers/gpu/drm/scheduler/tests/tests_basic.c | 476
>>>> ++++++++++++++++++
>>>>    8 files changed, 1199 insertions(+), 104 deletions(-)
>>>>    create mode 100644 drivers/gpu/drm/Kconfig.debug
>>>>    create mode 100644 drivers/gpu/drm/scheduler/.kunitconfig
>>>>    create mode 100644 drivers/gpu/drm/scheduler/tests/Makefile
>>>>    create mode 100644
>>>> drivers/gpu/drm/scheduler/tests/mock_scheduler.c
>>>>    create mode 100644
>>>> drivers/gpu/drm/scheduler/tests/sched_tests.h
>>>>    create mode 100644
>>>> drivers/gpu/drm/scheduler/tests/tests_basic.c
>>>>
>>>
>>
>
Tvrtko Ursulin March 12, 2025, 1:35 p.m. UTC | #5
On 12/03/2025 13:27, Tvrtko Ursulin wrote:
> 
> On 12/03/2025 12:35, Philipp Stanner wrote:
>> On Wed, 2025-03-12 at 10:50 +0000, Tvrtko Ursulin wrote:
>>>
>>> On 12/03/2025 10:39, Philipp Stanner wrote:
>>>> On Tue, 2025-03-11 at 09:23 +0000, Tvrtko Ursulin wrote:
>>>>> There has repeatedly been quite a bit of apprehension when any
>>>>> change
>>>>> to the DRM
>>>>> scheduler is proposed, with two main reasons being code base is
>>>>> considered
>>>>> fragile, not well understood and not very well documented, and
>>>>> secondly the lack
>>>>> of systematic testing outside the vendor specific tests suites
>>>>> and/or
>>>>> test
>>>>> farms.
>>>>>
>>>>> This series is an attempt to dislodge this status quo by adding
>>>>> some
>>>>> unit tests
>>>>> using the kunit framework.
>>>>>
>>>>> General approach is that there is a mock "hardware" backend which
>>>>> can
>>>>> be
>>>>> controlled from tests, which in turn allows exercising various
>>>>> scheduler code
>>>>> paths.
>>>>>
>>>>> Only some simple basic tests get added in the series and
>>>>> hopefully it
>>>>> is easy to
>>>>> understand what tests are doing.
>>>>>
>>>>> An obligatory "screenshot" for reference:
>>>>>
>>>>> [14:09:05] ============ drm_sched_basic_tests (3 subtests)
>>>>> ============
>>>>> [14:09:06] [PASSED] drm_sched_basic_submit
>>>>> [14:09:06] ================== drm_sched_basic_test
>>>>> ===================
>>>>> [14:09:06] [PASSED] A queue of jobs in a single entity
>>>>> [14:09:06] [PASSED] A chain of dependent jobs across multiple
>>>>> entities
>>>>> [14:09:06] [PASSED] Multiple independent job queues
>>>>> [14:09:06] [PASSED] Multiple inter-dependent job queues
>>>>> [14:09:07] ============== [PASSED] drm_sched_basic_test
>>>>> ===============
>>>>> [14:09:07] [PASSED] drm_sched_basic_entity_cleanup
>>>>> [14:09:07] ============== [PASSED] drm_sched_basic_tests
>>>>> ==============
>>>>> [14:09:07] ======== drm_sched_basic_timeout_tests (1 subtest)
>>>>> =========
>>>>> [14:09:08] [PASSED] drm_sched_basic_timeout
>>>>> [14:09:08] ========== [PASSED] drm_sched_basic_timeout_tests
>>>>> ==========
>>>>> [14:09:08] ======= drm_sched_basic_priority_tests (2 subtests)
>>>>> ========
>>>>> [14:09:10] [PASSED] drm_sched_priorities
>>>>> [14:09:10] [PASSED] drm_sched_change_priority
>>>>> [14:09:10] ========= [PASSED] drm_sched_basic_priority_tests
>>>>> ==========
>>>>> [14:09:10] ====== drm_sched_basic_modify_sched_tests (1 subtest)
>>>>> ======
>>>>> [14:09:11] [PASSED] drm_sched_test_modify_sched
>>>>> [14:09:11] ======= [PASSED] drm_sched_basic_modify_sched_tests
>>>>> ========
>>>>> [14:09:11] ======== drm_sched_basic_credits_tests (1 subtest)
>>>>> =========
>>>>> [14:09:12] [PASSED] drm_sched_test_credits
>>>>> [14:09:12] ========== [PASSED] drm_sched_basic_credits_tests
>>>>> ==========
>>>>> [14:09:12]
>>>>> ============================================================
>>>>> [14:09:12] Testing complete. Ran 11 tests: passed: 11
>>>>> [14:09:13] Elapsed time: 13.539s total, 0.001s configuring,
>>>>> 3.004s
>>>>> building, 10.462s running
>>>>>
>>>>> v2:
>>>>>    * Parameterize a bunch of similar tests.
>>>>>    * Improve test commentary.
>>>>>    * Rename TDR test to timeout. (Christian)
>>>>>    * Improve quality and consistency of naming. (Philipp)
>>>>>
>>>>> RFC v2 -> series v1:
>>>>>    * Rebased for drm_sched_init changes.
>>>>>    * Fixed modular build.
>>>>>    * Added some comments.
>>>>>    * Filename renames. (Philipp)
>>>>>
>>>>> v2:
>>>>>    * Dealt with a bunch of checkpatch warnings.
>>>>>
>>>>> v3:
>>>>>    * Some mock API renames, kerneldoc grammar fixes and
>>>>> indentation
>>>>> fixes.
>>>>>
>>>>> v4:
>>>>>    * Fix use after free caused by relying on scheduler fence for
>>>>> querying status.
>>>>>    * Kerneldoc fixes.
>>>>>
>>>>> v5:
>>>>>    * Cleanup in-flight jobs on scheduler shutdown.
>>>>>    * Change hang_limit to 1.
>>>>>
>>>>> v6:
>>>>>    * Use KUNIT_ASSERT_TRUE/FALSE.
>>>>>    * Fixed patch titles.
>>>>>    * Added credit_limit test.
>>>>
>>>> Please don't add new tests in a settled series. Doing so may seem
>>>> efficient, but causes another round of review and can cause you and
>>>> me
>>>> trouble when trying to find the cause of issues such as the one
>>>> mentioned below:
>>>>
>>>>>    * Added CONFIG_DRM_SCHED_KUNIT_TEST_ASPIRATIONAL.
>>>>>
>>>>> v7:
>>>>>    * v6 omitted to send the first patch by mistake.
>>>>
>>>> I either see a new NULL ptr deref added through the new test or an
>>>> old
>>>> one that has slipped us. My test setup is unchanged.
>>>
>>> All I see in what you pasted are kunit_test_null_dereference
>>> "crashes".
>>> Ie. expected ones from having enabled CONFIG_KUNIT_FAULT_TEST.
>>
>> Allright, didn't know about that. Help me out here quickly, so would
>> this option lead to a real fault on a real CPU? Or is it "simulated"?
> 
> AFAIU it is real faults where kunit test framework is testing itself 
> whether it can catch them.
> 
>>> Is there something more that you did not paste?
>>
>> No, that was all.
>>
>> I tried it again without the KUNIT_FAULT option and activated
>> aspirational mode. (on top of current drm-misc-next, eff0347e7c22).
>>
>> There I see a UAF. Do you have an idea what that might be? I would only
>> expect memory leaks and the test assertions failing.
> 
> It is expected all hell to break loose in aspirational mode. There the 
> mock scheduler shutdown relies solely on drm_sched_fini. So all tests 
> which do not fully idle the mock scheduler themselves, whether implicity 
> or explicitly, will explode in various ways.

To clarify I made it like that because that is what I understood was 
your vision for drm_sched_fini. That it would be able to clean 
everything up etc.

If you meant something different we need to adjust it. Although it could 
be done later as well.

Regards,

Tvrtko

>> [    3.976637] Demotion targets for Node 0: null
>> [    3.977265] kmemleak: Kernel memory leak detector initialized (mem 
>> pool available: 11277)
>> [    3.977274] kmemleak: Automatic memory scanning thread started
>> [    3.978604] PM:   Magic number: 1:529:430
>> [    3.978914] printk: legacy console [netcon0] enabled
>> [    3.979247] netconsole: network logging started
>> [    3.979839] cfg80211: Loading compiled-in X.509 certificates for 
>> regulatory database
>> [    3.980811] kworker/u72:1 (156) used greatest stack depth: 28552 
>> bytes left
>> [    3.981632] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
>> [    3.982437] Loaded X.509 cert 'wens: 
>> 61c038651aabdcf94bd0ac7ff06c7248db18c600'
>> [    3.983110] platform regulatory.0: Direct firmware load for 
>> regulatory.db failed with error -2
>> [    3.983578] KTAP version 1
>> [    3.983767] cfg80211: failed to load regulatory.db
>> [    3.983988] 1..5
>> [    3.984976]     KTAP version 1
>> [    3.985299]     # Subtest: drm_sched_basic_tests
>> [    3.985681]     # module: drm_sched_tests
>> [    3.985683]     1..3
>> [    4.319827] input: ImExPS/2 Generic Explorer Mouse as /devices/ 
>> platform/i8042/serio1/input/input3
>> [    4.495862]     ok 1 drm_sched_basic_submit
>> [    4.495879]         KTAP version 1
>> [    4.496468]         # Subtest: drm_sched_basic_test
>> [    4.598388]         ok 1 A queue of jobs in a single entity
>> [    4.700730]         ok 2 A chain of dependent jobs across multiple 
>> entities
>> [    4.803439]         ok 3 Multiple independent job queues
>> [    4.905560]         ok 4 Multiple inter-dependent job queues
>> [    4.906029]     # drm_sched_basic_test: pass:4 fail:0 skip:0 total:4
>> [    4.906500]     ok 2 drm_sched_basic_test
>> [    4.959366]     # drm_sched_basic_entity_cleanup: ASSERTION FAILED 
>> at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
>> [    4.959366]     Expected list_empty(&sched->job_list) to be true, 
>> but is false
>> [    4.961263]     # drm_sched_basic_entity_cleanup: test aborted 
>> during cleanup. continuing without cleaning up
>> [    4.961997]     not ok 3 drm_sched_basic_entity_cleanup
>> [    4.961999] # drm_sched_basic_tests: pass:2 fail:1 skip:0 total:3
>> [    4.962384] # Totals: pass:5 fail:1 skip:0 total:6
>> [    4.962823] not ok 1 drm_sched_basic_tests
>> [    4.963465]     KTAP version 1
>> [    4.963691]     # Subtest: drm_sched_basic_timeout_tests
>> [    4.964065]     # module: drm_sched_tests
>> [    4.964067]     1..1
>> [    6.503265]     # drm_sched_basic_timeout: ASSERTION FAILED at 
>> drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
>> [    6.503265]     Expected list_empty(&sched->job_list) to be true, 
>> but is false
>> [    6.504778]     # drm_sched_basic_timeout: test aborted during 
>> cleanup. continuing without cleaning up
>> [    6.505457]     not ok 1 drm_sched_basic_timeout
>> [    6.505460] not ok 2 drm_sched_basic_timeout_tests
>> [    6.506128]     KTAP version 1
>> [    6.506360]     # Subtest: drm_sched_basic_priority_tests
>> [    6.506751]     # module: drm_sched_tests
>> [    6.506753]     1..2
>> [    6.609082]     ok 1 drm_sched_priorities
>> [    7.614297]     ok 2 drm_sched_change_priority
>> [    7.614723] # drm_sched_basic_priority_tests: pass:2 fail:0 skip:0 
>> total:2
>> [    7.615130] # Totals: pass:2 fail:0 skip:0 total:2
>> [    7.615667] ok 3 drm_sched_basic_priority_tests
>> [    7.616344]     KTAP version 1
>> [    7.616580]     # Subtest: drm_sched_basic_modify_sched_tests
>> [    7.617039]     # module: drm_sched_tests
>> [    7.617042]     1..1
>> [    7.926594]     # drm_sched_test_modify_sched: ASSERTION FAILED at 
>> drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
>> [    7.926594]     Expected list_empty(&sched->job_list) to be true, 
>> but is false
>> [    7.928533] 
>> ==================================================================
>> [    7.929065] BUG: KASAN: slab-use-after-free in 
>> timerqueue_add+0x24e/0x320
>> [    7.929596] Read of size 8 at addr ffff8881092ec8e8 by task 
>> swapper/5/0
>> [    7.930092]
>> [    7.930251] CPU: 5 UID: 0 PID: 0 Comm: swapper/5 Tainted: 
>> G                 N 6.14.0-rc4-00476-ge1aa9011309e #6
>> [    7.930256] Tainted: [N]=TEST
>> [    7.930257] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), 
>> BIOS 1.16.3-2.fc40 04/01/2014
>> [    7.930258] Call Trace:
>> [    7.930260]  <IRQ>
>> [    7.930261]  dump_stack_lvl+0x53/0x70
>> [    7.930265]  print_report+0xce/0x680
>> [    7.930269]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
>> [    7.930271]  ? __pfx_calc_global_load_tick+0x10/0x10
>> [    7.930274]  ? timerqueue_add+0x24e/0x320
>> [    7.930276]  kasan_report+0xe2/0x120
>> [    7.930278]  ? timerqueue_add+0x24e/0x320
>> [    7.930280]  timerqueue_add+0x24e/0x320
>> [    7.930281]  __hrtimer_run_queues+0x358/0x6f0
>> [    7.930284]  ? __pfx___hrtimer_run_queues+0x10/0x10
>> [    7.930286]  ? ktime_get_update_offsets_now+0x7c/0x2c0
>> [    7.930288]  hrtimer_interrupt+0x2cd/0x7e0
>> [    7.930290]  __sysvec_apic_timer_interrupt+0x88/0x260
>> [    7.930293]  sysvec_apic_timer_interrupt+0x67/0x80
>> [    7.930295]  </IRQ>
>> [    7.930296]  <TASK>
>> [    7.930296]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
>> [    7.930299] RIP: 0010:default_idle+0xf/0x20
>> [    7.930302] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 
>> 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d b3 d6 06 
>> 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 
>> 90 90
>> [    7.930304] RSP: 0000:ffff888100b8fe70 EFLAGS: 00000206
>> [    7.930306] RAX: ffff888a8ec80000 RBX: 0000000000000005 RCX: 
>> ffffffffbb3b7c41
>> [    7.930308] RDX: ffffed1151d96a83 RSI: 0000000000000004 RDI: 
>> 0000000000036334
>> [    7.930309] RBP: ffffed1020161d58 R08: 0000000000000001 R09: 
>> ffffed1151d96a82
>> [    7.930309] R10: ffff888a8ecb5413 R11: 0000000000001400 R12: 
>> ffff888100b0eac0
>> [    7.930310] R13: ffffffffbc7f36d0 R14: 1ffff11020171fd2 R15: 
>> 0000000000000000
>> [    7.930312]  ? ct_kernel_exit.constprop.0+0xa1/0xc0
>> [    7.930314]  default_idle_call+0x3a/0x60
>> [    7.930316]  do_idle+0x2f2/0x3b0
>> [    7.930318]  ? __pfx_do_idle+0x10/0x10
>> [    7.930320]  ? __switch_to+0x5cd/0xe30
>> [    7.930323]  cpu_startup_entry+0x4f/0x60
>> [    7.930324]  start_secondary+0x1b7/0x210
>> [    7.930326]  common_startup_64+0x12c/0x138
>> [    7.930328]  </TASK>
>> [    7.930329]
>> [    7.931848]     not ok 1 drm_sched_test_modify_sched
>> [    7.932019] Allocated by task 187:
>> [    7.932285] not ok 4 drm_sched_basic_modify_sched_tests
>> [    7.932486]  kasan_save_stack+0x33/0x60
>> [    7.932835]     KTAP version 1
>> [    7.933153]  kasan_save_track+0x14/0x30
>> [    7.933156]  __kasan_kmalloc+0x8f/0xa0
>> [    7.933652]     # Subtest: drm_sched_basic_credits_tests
>> [    7.934095]  __kmalloc_noprof+0x18a/0x440
>> [    7.934494]     # module: drm_sched_tests
>> [    7.934817]  kunit_kmalloc_array+0x1b/0x50
>> [    7.935201]     1..1
>> [    7.935589]  drm_mock_sched_job_new+0x8f/0x400
>> [    7.935592]  drm_sched_test_modify_sched+0x1cd/0x490
>> [    7.950666]  kunit_try_run_case+0x1ae/0x490
>> [    7.950977]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
>> [    7.951400]  kthread+0x30f/0x620
>> [    7.951656]  ret_from_fork+0x2f/0x70
>> [    7.951936]  ret_from_fork_asm+0x1a/0x30
>> [    7.952250]
>> [    7.952373] Freed by task 192:
>> [    7.952605]  kasan_save_stack+0x33/0x60
>> [    7.952884]  kasan_save_track+0x14/0x30
>> [    7.953169]  kasan_save_free_info+0x3b/0x60
>> [    7.953495]  __kasan_slab_free+0x37/0x50
>> [    7.953797]  kfree+0x12f/0x350
>> [    7.954035]  kunit_remove_resource+0x130/0x1f0
>> [    7.954379]  kunit_cleanup+0x6e/0x110
>> [    7.954656]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
>> [    7.955044]  kthread+0x30f/0x620
>> [    7.955286]  ret_from_fork+0x2f/0x70
>> [    7.955557]  ret_from_fork_asm+0x1a/0x30
>> [    7.955844]
>> [    7.955956] The buggy address belongs to the object at 
>> ffff8881092ec800
>> [    7.955956]  which belongs to the cache kmalloc-512 of size 512
>> [    7.956883] The buggy address is located 232 bytes inside of
>> [    7.956883]  freed 512-byte region [ffff8881092ec800, 
>> ffff8881092eca00)
>> [    7.957790]
>> [    7.957904] The buggy address belongs to the physical page:
>> [    7.958324] page: refcount:0 mapcount:0 mapping:0000000000000000 
>> index:0x0 pfn:0x1092e8
>> [    7.958925] head: order:3 mapcount:0 entire_mapcount:0 
>> nr_pages_mapped:0 pincount:0
>> [    7.959527] flags: 0x200000000000040(head|node=0|zone=2)
>> [    7.959926] page_type: f5(slab)
>> [    7.960163] raw: 0200000000000040 ffff888100042c80 dead000000000122 
>> 0000000000000000
>> [    7.960743] raw: 0000000000000000 0000000080200020 00000000f5000000 
>> 0000000000000000
>> [    7.961304] head: 0200000000000040 ffff888100042c80 
>> dead000000000122 0000000000000000
>> [    7.961880] head: 0000000000000000 0000000080200020 
>> 00000000f5000000 0000000000000000
>> [    7.962460] head: 0200000000000003 ffffea000424ba01 
>> ffffffffffffffff 0000000000000000
>> [    7.963025] head: 0000000000000008 0000000000000000 
>> 00000000ffffffff 0000000000000000
>> [    7.963602] page dumped because: kasan: bad access detected
>> [    7.964001]
>> [    7.964113] Memory state around the buggy address:
>> [    7.964481]  ffff8881092ec780: fc fc fc fc fc fc fc fc fc fc fc fc 
>> fc fc fc fc
>> [    7.965007]  ffff8881092ec800: fa fb fb fb fb fb fb fb fb fb fb fb 
>> fb fb fb fb
>> [    7.965576] >ffff8881092ec880: fb fb fb fb fb fb fb fb fb fb fb fb 
>> fb fb fb fb
>> [    
>> 7.966120]                                                           ^
>> [    7.966625]  ffff8881092ec900: fb fb fb fb fb fb fb fb fb fb fb fb 
>> fb fb fb fb
>> [    7.967199]  ffff8881092ec980: fb fb fb fb fb fb fb fb fb fb fb fb 
>> fb fb fb fb
>> [    7.967734] 
>> ==================================================================
>> [    7.968267] Disabling lock debugging due to kernel taint
>> [    8.999147]     # drm_sched_test_credits: ASSERTION FAILED at 
>> drivers/gpu/drm/scheduler/tests/mock_scheduler.c:295
>> [    8.999147]     Expected list_empty(&sched->base.pending_list) to 
>> be true, but is false
>> [    9.001031]     not ok 1 drm_sched_test_credits
>> [    9.001034] not ok 5 drm_sched_basic_credits_tests
>>
>>
>>
>>>
>>>> On which commit do you apply and test this series? Tell me, then I
>>>> test again.
>>>
>>> Depending on the setup, these three:
>>>
>>> commit 413ae464b8021542ad90cb1fbb15f8efc5050a5d
>>> Author: Thomas Zimmermann <tzimmermann@suse.de>
>>> Date:   Mon Mar 3 16:41:48 2025 +0100
>>>
>>>       drm-tip: 2025y-03m-03d-15h-40m-53s UTC integration manifest
>>>
>>> commit 5bcb67a2a4c61034f5a25c024631c5fbf351ee8d
>>> Author: Matt Coster <matt.coster@imgtec.com>
>>> Date:   Wed Feb 26 10:01:09 2025 +0000
>>>
>>>       drm-tip: 2025y-02m-26d-09h-59m-48s UTC integration manifest
>>>
>>> commit 777e1850811f9864aa8b55940634d3da19712bf7
>>> Author: Imre Deak <imre.deak@intel.com>
>>> Date:   Tue Mar 11 11:31:04 2025 +0200
>>>
>>>       drm-tip: 2025y-03m-11d-09h-30m-13s UTC integration manifest
>>>
>>> Regards,
>>>
>>> Tvrtko
>>>
>>>> [    3.902457] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
>>>> [    3.903376] Loaded X.509 cert 'wens:
>>>> 61c038651aabdcf94bd0ac7ff06c7248db18c600'
>>>> [    3.904064] platform regulatory.0: Direct firmware load for
>>>> regulatory.db failed with error -2
>>>> [    3.904673] cfg80211: failed to load regulatory.db
>>>> [    3.905037] ALSA device list:
>>>> [    3.905376]   No soundcards found.
>>>> [    3.905631] KTAP version 1
>>>> [    3.905834] 1..17
>>>> [    3.906732]     KTAP version 1
>>>> [    3.906999]     # Subtest: kunit_executor_test
>>>> [    3.907335]     # module: kunit
>>>> [    3.907337]     1..8
>>>> [    3.908476]     ok 1 parse_filter_test
>>>> [    3.909064]     ok 2 filter_suites_test
>>>> [    3.909801]     ok 3 filter_suites_test_glob_test
>>>> [    3.910678]     ok 4 filter_suites_to_empty_test
>>>> [    3.911621]     ok 5 parse_filter_attr_test
>>>> [    3.912641]     ok 6 filter_attr_test
>>>> [    3.913511]     ok 7 filter_attr_empty_test
>>>> [    3.914081]     ok 8 filter_attr_skip_test
>>>> [    3.914400] # kunit_executor_test: pass:8 fail:0 skip:0 total:8
>>>> [    3.914685] # Totals: pass:8 fail:0 skip:0 total:8
>>>> [    3.915121] ok 1 kunit_executor_test
>>>> [    3.915736]     KTAP version 1
>>>> [    3.915949]     # Subtest: kunit-try-catch-test
>>>> [    3.916314]     # module: kunit_test
>>>> [    3.916315]     1..2
>>>> [    3.917655]     ok 1
>>>> kunit_test_try_catch_successful_try_no_catch
>>>> [    3.917979]     ok 2
>>>> kunit_test_try_catch_unsuccessful_try_does_catch
>>>> [    3.918630] # kunit-try-catch-test: pass:2 fail:0 skip:0 total:2
>>>> [    3.919118] # Totals: pass:2 fail:0 skip:0 total:2
>>>> [    3.919578] ok 2 kunit-try-catch-test
>>>> [    3.920248]     KTAP version 1
>>>> [    3.920473]     # Subtest: kunit-resource-test
>>>> [    3.920796]     # module: kunit_test
>>>> [    3.920797]     1..12
>>>> [    3.921565]     ok 1 kunit_resource_test_init_resources
>>>> [    3.921793]     ok 2 kunit_resource_test_alloc_resource
>>>> [    3.922449]     ok 3 kunit_resource_test_destroy_resource
>>>> [    3.923013]     ok 4 kunit_resource_test_remove_resource
>>>> [    3.924438]     ok 5 kunit_resource_test_cleanup_resources
>>>> [    3.925834]     ok 6 kunit_resource_test_proper_free_ordering
>>>> [    3.926700]     ok 7 kunit_resource_test_static
>>>> [    3.927588]     ok 8 kunit_resource_test_named
>>>> [    3.928244]     ok 9 kunit_resource_test_action
>>>> [    3.928774]     ok 10 kunit_resource_test_remove_action
>>>> [    3.929309]     ok 11 kunit_resource_test_release_action
>>>> [    3.929826] action_order_2
>>>> [    3.930325] action_order_2
>>>> [    3.930521] action_order_1
>>>> [    3.931007]     ok 12 kunit_resource_test_action_ordering
>>>> [    3.931308] # kunit-resource-test: pass:12 fail:0 skip:0
>>>> total:12
>>>> [    3.931702] # Totals: pass:12 fail:0 skip:0 total:12
>>>> [    3.932183] ok 3 kunit-resource-test
>>>> [    3.932809]     KTAP version 1
>>>> [    3.933040]     # Subtest: kunit-log-test
>>>> [    3.933367]     # module: kunit_test
>>>> [    3.933368]     1..2
>>>> [    3.934030] put this in log.
>>>> [    3.934033] this too.
>>>> [    3.934305] add to suite log.
>>>> [    3.934500] along with this.
>>>> [    3.934982]     ok 1 kunit_log_test
>>>> [    3.935405]     # kunit_log_newline_test: Add newline
>>>> [    3.936164]     ok 2 kunit_log_newline_test # SKIP only useful
>>>> when debugfs is enabled
>>>> [    3.936166] # kunit-log-test: pass:1 fail:0 skip:1 total:2
>>>> [    3.936752] # Totals: pass:1 fail:0 skip:1 total:2
>>>> [    3.937197] ok 4 kunit-log-test
>>>> [    3.937776]     KTAP version 1
>>>> [    3.938004]     # Subtest: kunit_status
>>>> [    3.938324]     # module: kunit_test
>>>> [    3.938325]     1..2
>>>> [    3.938921]     ok 1 kunit_status_set_failure_test
>>>> [    3.939049]     ok 2 kunit_status_mark_skipped_test
>>>> [    3.939445] # kunit_status: pass:2 fail:0 skip:0 total:2
>>>> [    3.939816] # Totals: pass:2 fail:0 skip:0 total:2
>>>> [    3.940436] ok 5 kunit_status
>>>> [    3.941142]     KTAP version 1
>>>> [    3.941508]     # Subtest: kunit_current
>>>> [    3.941793]     # module: kunit_test
>>>> [    3.941794]     1..2
>>>> [    3.942526]     ok 1 kunit_current_test
>>>> [    3.942596]     # fake test: lib/kunit/kunit-test.c:722: This
>>>> should make `fake` test fail.
>>>> [    3.943302]     ok 2 kunit_current_fail_test
>>>> [    3.943908] # kunit_current: pass:2 fail:0 skip:0 total:2
>>>> [    3.944271] # Totals: pass:2 fail:0 skip:0 total:2
>>>> [    3.944661] ok 6 kunit_current
>>>> [    3.945285]     KTAP version 1
>>>> [    3.945511]     # Subtest: kunit_device
>>>> [    3.945789]     # module: kunit_test
>>>> [    3.945790]     1..3
>>>> [    3.946905]     ok 1 kunit_device_test
>>>> [    3.947420]     ok 2 kunit_device_cleanup_test
>>>> [    3.948621]     ok 3 kunit_device_driver_test
>>>> [    3.948972] # kunit_device: pass:3 fail:0 skip:0 total:3
>>>> [    3.949349] # Totals: pass:3 fail:0 skip:0 total:3
>>>> [    3.949760] ok 7 kunit_device
>>>> [    3.950395]     KTAP version 1
>>>> [    3.950617]     # Subtest: kunit_fault
>>>> [    3.950889]     # module: kunit_test
>>>> [    3.950890]     1..1
>>>> [    3.951773] Oops: general protection fault, probably for non-
>>>> canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
>>>> PTI
>>>> [    3.952672] KASAN: null-ptr-deref in range [0x0000000000000000-
>>>> 0x0000000000000007]
>>>> [    3.953239] CPU: 2 UID: 0 PID: 225 Comm: kunit_try_catch
>>>> Tainted: G                 N 6.14.0-rc4-00388-g712b7c2f4d5d #21
>>>> [    3.954000] Tainted: [N]=TEST
>>>> [    3.954245] Hardware name: QEMU Standard PC (i440FX + PIIX,
>>>> 1996), BIOS 1.16.3-2.fc40 04/01/2014
>>>> [    3.954850] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
>>>> [    3.955285] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03
>>>> 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42
>>>> 04 01 f3 f3 f3 <0f> b6 04
>>>> [    3.956604] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
>>>> [    3.956972] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX:
>>>> ffffffffb65da11d
>>>> [    3.957651] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI:
>>>> ffff88810088fb30
>>>> [    3.958317] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09:
>>>> ffffed10207de600
>>>> [    3.958849] R10: ffff888103ef3007 R11: 0000000000000000 R12:
>>>> ffffffffb73baf40
>>>> [    3.959425] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15:
>>>> ffff8881091c6ac0
>>>> [    3.959917] FS:  0000000000000000(0000)
>>>> GS:ffff888a88700000(0000) knlGS:0000000000000000
>>>> [    3.960521] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>> [    3.960920] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4:
>>>> 00000000000006f0
>>>> [    3.961480] Call Trace:
>>>> [    3.961655]  <TASK>
>>>> [    3.961805]  ? die_addr+0x3b/0xa0
>>>> [    3.962052]  ? exc_general_protection+0x151/0x220
>>>> [    3.962439]  ? asm_exc_general_protection+0x26/0x30
>>>> [    3.962801]  ?
>>>> __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
>>>> [    3.963447]  ? __pfx_kunit_test_null_dereference+0x10/0x10
>>>> [    3.964150]  ? __kthread_parkme+0x7d/0x140
>>>> [    3.964443]  ? kunit_test_null_dereference+0x4a/0x150
>>>> [    3.964785]  ? __pfx_kunit_test_null_dereference+0x10/0x10
>>>> [    3.965205]  ? __kthread_parkme+0x7d/0x140
>>>> [    3.965494]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
>>>> [    3.965859]  kthread+0x30f/0x620
>>>> [    3.966108]  ? __pfx_kthread+0x10/0x10
>>>> [    3.966406]  ? __pfx_kthread+0x10/0x10
>>>> [    3.966680]  ret_from_fork+0x2f/0x70
>>>> [    3.966941]  ? __pfx_kthread+0x10/0x10
>>>> [    3.967264]  ret_from_fork_asm+0x1a/0x30
>>>> [    3.967560]  </TASK>
>>>> [    3.967722] Modules linked in:
>>>> [    3.967989] ---[ end trace 0000000000000000 ]---
>>>> [    3.968368] RIP: 0010:kunit_test_null_dereference+0x4a/0x150
>>>> [    3.968780] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1 ed 03
>>>> 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1 c7 42
>>>> 04 01 f3 f3 f3 <0f> b6 04
>>>> [    3.970211] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
>>>> [    3.970567] RAX: dffffc0000000000 RBX: ffff88810088fb30 RCX:
>>>> ffffffffb65da11d
>>>> [    3.971074] RDX: ffffed1021241fc0 RSI: 0000000000000008 RDI:
>>>> ffff88810088fb30
>>>> [    3.971580] RBP: 1ffff11021241fc0 R08: 0000000000000000 R09:
>>>> ffffed10207de600
>>>> [    3.972089] R10: ffff888103ef3007 R11: 0000000000000000 R12:
>>>> ffffffffb73baf40
>>>> [    3.972629] R13: ffffffffb73b1c60 R14: ffff8881038a9d80 R15:
>>>> ffff8881091c6ac0
>>>> [    3.973176] FS:  0000000000000000(0000)
>>>> GS:ffff888a88700000(0000) knlGS:0000000000000000
>>>> [    3.973720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>> [    3.974148] CR2: 0000000000000000 CR3: 0000000b1406a000 CR4:
>>>> 00000000000006f0
>>>> [    3.974659] kunit_try_catch (225) used greatest stack depth:
>>>> 28416 bytes left
>>>> [    3.974764]     # kunit_test_fault_null_dereference: try
>>>> faulted: last line seen lib/kunit/kunit-test.c:95
>>>> [    3.976367]     ok 1 kunit_test_fault_null_dereference
>>>> [    3.976370] ok 8 kunit_fault
>>>> [    3.976946]     KTAP version 1
>>>> [    3.977208]     # Subtest: kunit_platform_device
>>>> [    3.977549]     # module: platform_test
>>>> [    3.977550]     1..4
>>>> [    3.978550]     ok 1 kunit_platform_device_alloc_test
>>>> [    3.978989]     ok 2 kunit_platform_device_add_test
>>>> [    3.980097] sysfs: cannot create duplicate filename
>>>> '/devices/platform/kunit-platform-add-2'
>>>> [    3.981138] CPU: 7 UID: 0 PID: 231 Comm: kunit_try_catch
>>>> Tainted: G      D          N 6.14.0-rc4-00388-g712b7c2f4d5d #21
>>>> [    3.981142] Tainted: [D]=DIE, [N]=TEST
>>>> [    3.981143] Hardware name: QEMU Standard PC (i440FX + PIIX,
>>>> 1996), BIOS 1.16.3-2.fc40 04/01/2014
>>>> [    3.981144] Call Trace:
>>>> [    3.981145]  <TASK>
>>>> [    3.981146]  dump_stack_lvl+0x53/0x70
>>>> [    3.981151]  sysfs_warn_dup+0x70/0x90
>>>> [    3.981154]  sysfs_create_dir_ns+0x209/0x280
>>>> [    3.981156]  ? __pfx_sysfs_create_dir_ns+0x10/0x10
>>>> [    3.981159]  ? _raw_spin_lock+0x80/0xe0
>>>> [    3.981161]  kobject_add_internal+0x216/0x8b0
>>>> [    3.981163]  kobject_add+0x13b/0x200
>>>> [    3.981165]  ? __pfx_kobject_add+0x10/0x10
>>>> [    3.981167]  ? kobject_get+0x50/0xe0
>>>> [    3.981169]  device_add+0x217/0x1460
>>>> [    3.981171]  ? __pfx_device_add+0x10/0x10
>>>> [    3.981173]  ? _raw_spin_lock_irqsave+0x86/0xe0
>>>> [    3.981174]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
>>>> [    3.981176]  ? device_initialize+0x1f4/0x410
>>>> [    3.981179]  ? platform_device_alloc+0x97/0x200
>>>> [    3.981182]  platform_device_add+0x375/0x5b0
>>>> [    3.981184]  kunit_platform_device_add+0x20/0x2c0
>>>> [    3.981186]
>>>> kunit_platform_device_add_twice_fails_test+0x1f5/0x420
>>>> [    3.981189]  ?
>>>> __pfx_kunit_platform_device_add_twice_fails_test+0x10/0x10
>>>> [    3.981191]  ? __schedule+0xdda/0x24f0
>>>> [    3.981193]  ? kvm_clock_get_cycles+0x18/0x30
>>>> [    3.981196]  ? ktime_get_ts64+0x7d/0x220
>>>> [    3.981200]  kunit_try_run_case+0x1ae/0x490
>>>> [    3.981202]  ? __pfx_kunit_try_run_case+0x10/0x10
>>>> [    3.981204]  ? _raw_spin_lock_irqsave+0x86/0xe0
>>>> [    3.981205]  ? __pfx_kunit_try_run_case+0x10/0x10
>>>> [    3.981207]  ?
>>>> __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
>>>> [    3.981210]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
>>>> [    3.981212]  kthread+0x30f/0x620
>>>> [    3.981214]  ? __pfx_kthread+0x10/0x10
>>>> [    3.981216]  ? __pfx_kthread+0x10/0x10
>>>> [    3.981217]  ret_from_fork+0x2f/0x70
>>>> [    3.981223]  ? __pfx_kthread+0x10/0x10
>>>> [    3.981225]  ret_from_fork_asm+0x1a/0x30
>>>> [    3.981227]  </TASK>
>>>> [    3.981232] kobject: kobject_add_internal failed for kunit-
>>>> platform-add-2 with -EEXIST, don't try to register things with the
>>>> same name in the same direc.
>>>> [    3.995255] kunit_try_catch (231) used greatest stack depth:
>>>> 27528 bytes left
>>>> [    3.995525]     ok 3 kunit_platform_device_add_twice_fails_test
>>>> [    3.996247]     ok 4 kunit_platform_device_add_cleans_up
>>>> [    3.996678] # kunit_platform_device: pass:4 fail:0 skip:0
>>>> total:4
>>>> [    3.997073] # Totals: pass:4 fail:0 skip:0 total:4
>>>> [    3.997530] ok 9 kunit_platform_device
>>>> [    3.998130]     KTAP version 1
>>>> [    3.998356]     # Subtest: kunit_platform_driver
>>>> [    3.998664]     # module: platform_test
>>>> [    3.998665]     1..2
>>>> [    3.999663]     ok 1 kunit_platform_driver_register_test
>>>> [    4.000372]     ok 2
>>>> kunit_platform_device_prepare_wait_for_probe_completes_when_already
>>>> _probed
>>>> [    4.000750] # kunit_platform_driver: pass:2 fail:0 skip:0
>>>> total:2
>>>> [    4.001372] # Totals: pass:2 fail:0 skip:0 total:2
>>>> [    4.001777] ok 10 kunit_platform_driver
>>>> [    4.002412]     KTAP version 1
>>>> [    4.002618]     # Subtest: string-stream-test
>>>> [    4.002909]     # module: string_stream_test
>>>> [    4.002910]     1..12
>>>> [    4.003643]     ok 1 string_stream_managed_init_test
>>>> [    4.003919]     ok 2 string_stream_unmanaged_init_test
>>>> [    4.004581]     ok 3 string_stream_managed_free_test
>>>> [    4.005295]     ok 4 string_stream_resource_free_test
>>>> [    4.007076]     ok 5 string_stream_line_add_test
>>>> [    4.008801]     ok 6 string_stream_variable_length_line_test
>>>> [    4.009944]     ok 7 string_stream_append_test
>>>> [    4.010840]     ok 8 string_stream_append_auto_newline_test
>>>> [    4.011461]     ok 9 string_stream_append_empty_string_test
>>>> [    4.012233]     ok 10 string_stream_no_auto_newline_test
>>>> [    4.013158]     ok 11 string_stream_auto_newline_test
>>>> [    4.063760]     # string_stream_performance_test: Time
>>>> elapsed:           49385 us
>>>> [    4.064713]     # string_stream_performance_test: Total string
>>>> length:    573890
>>>> [    4.065271]     # string_stream_performance_test: Bytes
>>>> requested:        823930
>>>> [    4.065803]     # string_stream_performance_test: Actual bytes
>>>> allocated: 1048312
>>>> [    4.098820]     ok 12 string_stream_performance_test
>>>> [    4.098826] # string-stream-test: pass:12 fail:0 skip:0 total:12
>>>> [    4.099348] # Totals: pass:12 fail:0 skip:0 total:12
>>>> [    4.099814] ok 11 string-stream-test
>>>> [    4.100495]     KTAP version 1
>>>> [    4.100735]     # Subtest: kunit-assert
>>>> [    4.101048]     # module: assert_test
>>>> [    4.101050]     1..11
>>>> [    4.101943]     ok 1 kunit_test_is_literal
>>>> [    4.102331]     ok 2 kunit_test_is_str_literal
>>>> [    4.103177]     ok 3 kunit_test_assert_prologue
>>>> [    4.103996]     ok 4 kunit_test_assert_print_msg
>>>> [    4.104867]     ok 5 kunit_test_unary_assert_format
>>>> [    4.105908]     ok 6 kunit_test_ptr_not_err_assert_format
>>>> [    4.107022]     ok 7 kunit_test_binary_assert_format
>>>> [    4.107868]     ok 8 kunit_test_binary_ptr_assert_format
>>>> [    4.108702]     ok 9 kunit_test_binary_str_assert_format
>>>> [    4.109969]     ok 10 kunit_test_assert_hexdump
>>>> [    4.111490]     ok 11 kunit_test_mem_assert_format
>>>> [    4.111845] # kunit-assert: pass:11 fail:0 skip:0 total:11
>>>> [    4.112522] # Totals: pass:11 fail:0 skip:0 total:11
>>>> [    4.112949] ok 12 kunit-assert
>>>> [    4.113628]     KTAP version 1
>>>> [    4.113867]     # Subtest: drm_sched_basic_tests
>>>> [    4.114281]     # module: drm_sched_tests
>>>> [    4.114283]     1..3
>>>> [    4.234223] input: ImExPS/2 Generic Explorer Mouse as
>>>> /devices/platform/i8042/serio1/input/input3
>>>> [    4.617191]     ok 1 drm_sched_basic_submit
>>>> [    4.617197]         KTAP version 1
>>>> [    4.617765]         # Subtest: drm_sched_basic_test
>>>> [    4.719657]         ok 1 A queue of jobs in a single entity
>>>> [    4.821976]         ok 2 A chain of dependent jobs across
>>>> multiple entities
>>>> [    4.924015]         ok 3 Multiple independent job queues
>>>> [    5.026465]         ok 4 Multiple inter-dependent job queues
>>>> [    5.026907]     # drm_sched_basic_test: pass:4 fail:0 skip:0
>>>> total:4
>>>> [    5.027322]     ok 2 drm_sched_basic_test
>>>> [    5.080020]     ok 3 drm_sched_basic_entity_cleanup
>>>> [    5.080317] # drm_sched_basic_tests: pass:3 fail:0 skip:0
>>>> total:3
>>>> [    5.080657] # Totals: pass:6 fail:0 skip:0 total:6
>>>> [    5.081103] ok 13 drm_sched_basic_tests
>>>> [    5.081679]     KTAP version 1
>>>> [    5.081881]     # Subtest: drm_sched_basic_timeout_tests
>>>> [    5.082259]     # module: drm_sched_tests
>>>> [    5.082260]     1..1
>>>>
>>>>
>>>>
>>>>>
>>>>> Cc: Christian König <christian.koenig@amd.com>
>>>>> Cc: Danilo Krummrich <dakr@kernel.org>
>>>>> Cc: Matthew Brost <matthew.brost@intel.com>
>>>>> Cc: Philipp Stanner <phasta@kernel.org>
>>>>>
>>>>> Tvrtko Ursulin (7):
>>>>>     drm: Move some options to separate new Kconfig
>>>>>     drm/sched: Add scheduler unit testing infrastructure and some
>>>>> basic
>>>>>       tests
>>>>>     drm/sched: Add aspirational unit test mode
>>>>>     drm/sched: Add a simple timeout test
>>>>>     drm/sched: Add basic priority tests
>>>>>     drm/sched: Add a basic test for modifying entities scheduler
>>>>> list
>>>>>     drm/sched: Add a basic test for checking credit limit
>>>>>
>>>>>    drivers/gpu/drm/Kconfig                       | 109 +---
>>>>>    drivers/gpu/drm/Kconfig.debug                 | 128 +++++
>>>>>    drivers/gpu/drm/scheduler/.kunitconfig        |  12 +
>>>>>    drivers/gpu/drm/scheduler/Makefile            |   2 +
>>>>>    drivers/gpu/drm/scheduler/tests/Makefile      |   7 +
>>>>>    .../gpu/drm/scheduler/tests/mock_scheduler.c  | 345
>>>>> +++++++++++++
>>>>>    drivers/gpu/drm/scheduler/tests/sched_tests.h | 224 +++++++++
>>>>>    drivers/gpu/drm/scheduler/tests/tests_basic.c | 476
>>>>> ++++++++++++++++++
>>>>>    8 files changed, 1199 insertions(+), 104 deletions(-)
>>>>>    create mode 100644 drivers/gpu/drm/Kconfig.debug
>>>>>    create mode 100644 drivers/gpu/drm/scheduler/.kunitconfig
>>>>>    create mode 100644 drivers/gpu/drm/scheduler/tests/Makefile
>>>>>    create mode 100644
>>>>> drivers/gpu/drm/scheduler/tests/mock_scheduler.c
>>>>>    create mode 100644
>>>>> drivers/gpu/drm/scheduler/tests/sched_tests.h
>>>>>    create mode 100644
>>>>> drivers/gpu/drm/scheduler/tests/tests_basic.c
>>>>>
>>>>
>>>
>>
>
Philipp Stanner March 12, 2025, 1:49 p.m. UTC | #6
On Wed, 2025-03-12 at 13:35 +0000, Tvrtko Ursulin wrote:
> 
> On 12/03/2025 13:27, Tvrtko Ursulin wrote:
> > 
> > On 12/03/2025 12:35, Philipp Stanner wrote:
> > > On Wed, 2025-03-12 at 10:50 +0000, Tvrtko Ursulin wrote:
> > > > 
> > > > On 12/03/2025 10:39, Philipp Stanner wrote:
> > > > > On Tue, 2025-03-11 at 09:23 +0000, Tvrtko Ursulin wrote:
> > > > > > There has repeatedly been quite a bit of apprehension when
> > > > > > any
> > > > > > change
> > > > > > to the DRM
> > > > > > scheduler is proposed, with two main reasons being code
> > > > > > base is
> > > > > > considered
> > > > > > fragile, not well understood and not very well documented,
> > > > > > and
> > > > > > secondly the lack
> > > > > > of systematic testing outside the vendor specific tests
> > > > > > suites
> > > > > > and/or
> > > > > > test
> > > > > > farms.
> > > > > > 
> > > > > > This series is an attempt to dislodge this status quo by
> > > > > > adding
> > > > > > some
> > > > > > unit tests
> > > > > > using the kunit framework.
> > > > > > 
> > > > > > General approach is that there is a mock "hardware" backend
> > > > > > which
> > > > > > can
> > > > > > be
> > > > > > controlled from tests, which in turn allows exercising
> > > > > > various
> > > > > > scheduler code
> > > > > > paths.
> > > > > > 
> > > > > > Only some simple basic tests get added in the series and
> > > > > > hopefully it
> > > > > > is easy to
> > > > > > understand what tests are doing.
> > > > > > 
> > > > > > An obligatory "screenshot" for reference:
> > > > > > 
> > > > > > [14:09:05] ============ drm_sched_basic_tests (3 subtests)
> > > > > > ============
> > > > > > [14:09:06] [PASSED] drm_sched_basic_submit
> > > > > > [14:09:06] ================== drm_sched_basic_test
> > > > > > ===================
> > > > > > [14:09:06] [PASSED] A queue of jobs in a single entity
> > > > > > [14:09:06] [PASSED] A chain of dependent jobs across
> > > > > > multiple
> > > > > > entities
> > > > > > [14:09:06] [PASSED] Multiple independent job queues
> > > > > > [14:09:06] [PASSED] Multiple inter-dependent job queues
> > > > > > [14:09:07] ============== [PASSED] drm_sched_basic_test
> > > > > > ===============
> > > > > > [14:09:07] [PASSED] drm_sched_basic_entity_cleanup
> > > > > > [14:09:07] ============== [PASSED] drm_sched_basic_tests
> > > > > > ==============
> > > > > > [14:09:07] ======== drm_sched_basic_timeout_tests (1
> > > > > > subtest)
> > > > > > =========
> > > > > > [14:09:08] [PASSED] drm_sched_basic_timeout
> > > > > > [14:09:08] ========== [PASSED]
> > > > > > drm_sched_basic_timeout_tests
> > > > > > ==========
> > > > > > [14:09:08] ======= drm_sched_basic_priority_tests (2
> > > > > > subtests)
> > > > > > ========
> > > > > > [14:09:10] [PASSED] drm_sched_priorities
> > > > > > [14:09:10] [PASSED] drm_sched_change_priority
> > > > > > [14:09:10] ========= [PASSED]
> > > > > > drm_sched_basic_priority_tests
> > > > > > ==========
> > > > > > [14:09:10] ====== drm_sched_basic_modify_sched_tests (1
> > > > > > subtest)
> > > > > > ======
> > > > > > [14:09:11] [PASSED] drm_sched_test_modify_sched
> > > > > > [14:09:11] ======= [PASSED]
> > > > > > drm_sched_basic_modify_sched_tests
> > > > > > ========
> > > > > > [14:09:11] ======== drm_sched_basic_credits_tests (1
> > > > > > subtest)
> > > > > > =========
> > > > > > [14:09:12] [PASSED] drm_sched_test_credits
> > > > > > [14:09:12] ========== [PASSED]
> > > > > > drm_sched_basic_credits_tests
> > > > > > ==========
> > > > > > [14:09:12]
> > > > > > ===========================================================
> > > > > > =
> > > > > > [14:09:12] Testing complete. Ran 11 tests: passed: 11
> > > > > > [14:09:13] Elapsed time: 13.539s total, 0.001s configuring,
> > > > > > 3.004s
> > > > > > building, 10.462s running
> > > > > > 
> > > > > > v2:
> > > > > >    * Parameterize a bunch of similar tests.
> > > > > >    * Improve test commentary.
> > > > > >    * Rename TDR test to timeout. (Christian)
> > > > > >    * Improve quality and consistency of naming. (Philipp)
> > > > > > 
> > > > > > RFC v2 -> series v1:
> > > > > >    * Rebased for drm_sched_init changes.
> > > > > >    * Fixed modular build.
> > > > > >    * Added some comments.
> > > > > >    * Filename renames. (Philipp)
> > > > > > 
> > > > > > v2:
> > > > > >    * Dealt with a bunch of checkpatch warnings.
> > > > > > 
> > > > > > v3:
> > > > > >    * Some mock API renames, kerneldoc grammar fixes and
> > > > > > indentation
> > > > > > fixes.
> > > > > > 
> > > > > > v4:
> > > > > >    * Fix use after free caused by relying on scheduler
> > > > > > fence for
> > > > > > querying status.
> > > > > >    * Kerneldoc fixes.
> > > > > > 
> > > > > > v5:
> > > > > >    * Cleanup in-flight jobs on scheduler shutdown.
> > > > > >    * Change hang_limit to 1.
> > > > > > 
> > > > > > v6:
> > > > > >    * Use KUNIT_ASSERT_TRUE/FALSE.
> > > > > >    * Fixed patch titles.
> > > > > >    * Added credit_limit test.
> > > > > 
> > > > > Please don't add new tests in a settled series. Doing so may
> > > > > seem
> > > > > efficient, but causes another round of review and can cause
> > > > > you and
> > > > > me
> > > > > trouble when trying to find the cause of issues such as the
> > > > > one
> > > > > mentioned below:
> > > > > 
> > > > > >    * Added CONFIG_DRM_SCHED_KUNIT_TEST_ASPIRATIONAL.
> > > > > > 
> > > > > > v7:
> > > > > >    * v6 omitted to send the first patch by mistake.
> > > > > 
> > > > > I either see a new NULL ptr deref added through the new test
> > > > > or an
> > > > > old
> > > > > one that has slipped us. My test setup is unchanged.
> > > > 
> > > > All I see in what you pasted are kunit_test_null_dereference
> > > > "crashes".
> > > > Ie. expected ones from having enabled CONFIG_KUNIT_FAULT_TEST.
> > > 
> > > Allright, didn't know about that. Help me out here quickly, so
> > > would
> > > this option lead to a real fault on a real CPU? Or is it
> > > "simulated"?
> > 
> > AFAIU it is real faults where kunit test framework is testing
> > itself 
> > whether it can catch them.
> > 
> > > > Is there something more that you did not paste?
> > > 
> > > No, that was all.
> > > 
> > > I tried it again without the KUNIT_FAULT option and activated
> > > aspirational mode. (on top of current drm-misc-next,
> > > eff0347e7c22).
> > > 
> > > There I see a UAF. Do you have an idea what that might be? I
> > > would only
> > > expect memory leaks and the test assertions failing.
> > 
> > It is expected all hell to break loose in aspirational mode. There
> > the 
> > mock scheduler shutdown relies solely on drm_sched_fini. So all
> > tests 
> > which do not fully idle the mock scheduler themselves, whether
> > implicity 
> > or explicitly, will explode in various ways.
> 
> To clarify I made it like that because that is what I understood was 
> your vision for drm_sched_fini. That it would be able to clean 
> everything up etc.
> 
> If you meant something different we need to adjust it. Although it
> could 
> be done later as well.

My primary intention was to use those tests to see whether my memory
leak fix works or not.

Thus I'd need something like in v4, where the tests run as intended but
leak the jobs in the pending_list. Would indeed be neat if they also
check for list_len(pending_list) so that you don't have to run kmemleak
manually.

And since we shouldn't have such leaks in production tests the idea of
optionally enabling them arose.

More generally speaking, I think that the tests should behave as we
expect drivers to behave *currently*, while we have the option for the
tests to purposefully misbehave. In my case this means: just leak the
jobs and optionally tell about the leaks.

When used as intended, the scheduler currently AFAIK doesn't have UAF
or nullptrderefs, so they shouldn't occur in tests that use it as
intended. Now the leaks are special because we never intended them.

So what surprised me is that, when compared to v4, this v7 here
actually now also has UAF. Besides not cleaning up leaks, what are you
doing in aspiritional mode?

Let's talk it through before you invest your time into v8


P.


> 
> Regards,
> 
> Tvrtko
> 
> > > [    3.976637] Demotion targets for Node 0: null
> > > [    3.977265] kmemleak: Kernel memory leak detector initialized
> > > (mem 
> > > pool available: 11277)
> > > [    3.977274] kmemleak: Automatic memory scanning thread started
> > > [    3.978604] PM:   Magic number: 1:529:430
> > > [    3.978914] printk: legacy console [netcon0] enabled
> > > [    3.979247] netconsole: network logging started
> > > [    3.979839] cfg80211: Loading compiled-in X.509 certificates
> > > for 
> > > regulatory database
> > > [    3.980811] kworker/u72:1 (156) used greatest stack depth:
> > > 28552 
> > > bytes left
> > > [    3.981632] Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
> > > [    3.982437] Loaded X.509 cert 'wens: 
> > > 61c038651aabdcf94bd0ac7ff06c7248db18c600'
> > > [    3.983110] platform regulatory.0: Direct firmware load for 
> > > regulatory.db failed with error -2
> > > [    3.983578] KTAP version 1
> > > [    3.983767] cfg80211: failed to load regulatory.db
> > > [    3.983988] 1..5
> > > [    3.984976]     KTAP version 1
> > > [    3.985299]     # Subtest: drm_sched_basic_tests
> > > [    3.985681]     # module: drm_sched_tests
> > > [    3.985683]     1..3
> > > [    4.319827] input: ImExPS/2 Generic Explorer Mouse as
> > > /devices/ 
> > > platform/i8042/serio1/input/input3
> > > [    4.495862]     ok 1 drm_sched_basic_submit
> > > [    4.495879]         KTAP version 1
> > > [    4.496468]         # Subtest: drm_sched_basic_test
> > > [    4.598388]         ok 1 A queue of jobs in a single entity
> > > [    4.700730]         ok 2 A chain of dependent jobs across
> > > multiple 
> > > entities
> > > [    4.803439]         ok 3 Multiple independent job queues
> > > [    4.905560]         ok 4 Multiple inter-dependent job queues
> > > [    4.906029]     # drm_sched_basic_test: pass:4 fail:0 skip:0
> > > total:4
> > > [    4.906500]     ok 2 drm_sched_basic_test
> > > [    4.959366]     # drm_sched_basic_entity_cleanup: ASSERTION
> > > FAILED 
> > > at drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
> > > [    4.959366]     Expected list_empty(&sched->job_list) to be
> > > true, 
> > > but is false
> > > [    4.961263]     # drm_sched_basic_entity_cleanup: test aborted
> > > during cleanup. continuing without cleaning up
> > > [    4.961997]     not ok 3 drm_sched_basic_entity_cleanup
> > > [    4.961999] # drm_sched_basic_tests: pass:2 fail:1 skip:0
> > > total:3
> > > [    4.962384] # Totals: pass:5 fail:1 skip:0 total:6
> > > [    4.962823] not ok 1 drm_sched_basic_tests
> > > [    4.963465]     KTAP version 1
> > > [    4.963691]     # Subtest: drm_sched_basic_timeout_tests
> > > [    4.964065]     # module: drm_sched_tests
> > > [    4.964067]     1..1
> > > [    6.503265]     # drm_sched_basic_timeout: ASSERTION FAILED at
> > > drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
> > > [    6.503265]     Expected list_empty(&sched->job_list) to be
> > > true, 
> > > but is false
> > > [    6.504778]     # drm_sched_basic_timeout: test aborted during
> > > cleanup. continuing without cleaning up
> > > [    6.505457]     not ok 1 drm_sched_basic_timeout
> > > [    6.505460] not ok 2 drm_sched_basic_timeout_tests
> > > [    6.506128]     KTAP version 1
> > > [    6.506360]     # Subtest: drm_sched_basic_priority_tests
> > > [    6.506751]     # module: drm_sched_tests
> > > [    6.506753]     1..2
> > > [    6.609082]     ok 1 drm_sched_priorities
> > > [    7.614297]     ok 2 drm_sched_change_priority
> > > [    7.614723] # drm_sched_basic_priority_tests: pass:2 fail:0
> > > skip:0 
> > > total:2
> > > [    7.615130] # Totals: pass:2 fail:0 skip:0 total:2
> > > [    7.615667] ok 3 drm_sched_basic_priority_tests
> > > [    7.616344]     KTAP version 1
> > > [    7.616580]     # Subtest: drm_sched_basic_modify_sched_tests
> > > [    7.617039]     # module: drm_sched_tests
> > > [    7.617042]     1..1
> > > [    7.926594]     # drm_sched_test_modify_sched: ASSERTION
> > > FAILED at 
> > > drivers/gpu/drm/scheduler/tests/mock_scheduler.c:294
> > > [    7.926594]     Expected list_empty(&sched->job_list) to be
> > > true, 
> > > but is false
> > > [    7.928533] 
> > > =================================================================
> > > =
> > > [    7.929065] BUG: KASAN: slab-use-after-free in 
> > > timerqueue_add+0x24e/0x320
> > > [    7.929596] Read of size 8 at addr ffff8881092ec8e8 by task 
> > > swapper/5/0
> > > [    7.930092]
> > > [    7.930251] CPU: 5 UID: 0 PID: 0 Comm: swapper/5 Tainted: 
> > > G                 N 6.14.0-rc4-00476-ge1aa9011309e #6
> > > [    7.930256] Tainted: [N]=TEST
> > > [    7.930257] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > > 1996), 
> > > BIOS 1.16.3-2.fc40 04/01/2014
> > > [    7.930258] Call Trace:
> > > [    7.930260]  <IRQ>
> > > [    7.930261]  dump_stack_lvl+0x53/0x70
> > > [    7.930265]  print_report+0xce/0x680
> > > [    7.930269]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> > > [    7.930271]  ? __pfx_calc_global_load_tick+0x10/0x10
> > > [    7.930274]  ? timerqueue_add+0x24e/0x320
> > > [    7.930276]  kasan_report+0xe2/0x120
> > > [    7.930278]  ? timerqueue_add+0x24e/0x320
> > > [    7.930280]  timerqueue_add+0x24e/0x320
> > > [    7.930281]  __hrtimer_run_queues+0x358/0x6f0
> > > [    7.930284]  ? __pfx___hrtimer_run_queues+0x10/0x10
> > > [    7.930286]  ? ktime_get_update_offsets_now+0x7c/0x2c0
> > > [    7.930288]  hrtimer_interrupt+0x2cd/0x7e0
> > > [    7.930290]  __sysvec_apic_timer_interrupt+0x88/0x260
> > > [    7.930293]  sysvec_apic_timer_interrupt+0x67/0x80
> > > [    7.930295]  </IRQ>
> > > [    7.930296]  <TASK>
> > > [    7.930296]  asm_sysvec_apic_timer_interrupt+0x1a/0x20
> > > [    7.930299] RIP: 0010:default_idle+0xf/0x20
> > > [    7.930302] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90
> > > 90 
> > > 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d b3 d6
> > > 06 
> > > 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90
> > > 90 90 
> > > 90 90
> > > [    7.930304] RSP: 0000:ffff888100b8fe70 EFLAGS: 00000206
> > > [    7.930306] RAX: ffff888a8ec80000 RBX: 0000000000000005 RCX: 
> > > ffffffffbb3b7c41
> > > [    7.930308] RDX: ffffed1151d96a83 RSI: 0000000000000004 RDI: 
> > > 0000000000036334
> > > [    7.930309] RBP: ffffed1020161d58 R08: 0000000000000001 R09: 
> > > ffffed1151d96a82
> > > [    7.930309] R10: ffff888a8ecb5413 R11: 0000000000001400 R12: 
> > > ffff888100b0eac0
> > > [    7.930310] R13: ffffffffbc7f36d0 R14: 1ffff11020171fd2 R15: 
> > > 0000000000000000
> > > [    7.930312]  ? ct_kernel_exit.constprop.0+0xa1/0xc0
> > > [    7.930314]  default_idle_call+0x3a/0x60
> > > [    7.930316]  do_idle+0x2f2/0x3b0
> > > [    7.930318]  ? __pfx_do_idle+0x10/0x10
> > > [    7.930320]  ? __switch_to+0x5cd/0xe30
> > > [    7.930323]  cpu_startup_entry+0x4f/0x60
> > > [    7.930324]  start_secondary+0x1b7/0x210
> > > [    7.930326]  common_startup_64+0x12c/0x138
> > > [    7.930328]  </TASK>
> > > [    7.930329]
> > > [    7.931848]     not ok 1 drm_sched_test_modify_sched
> > > [    7.932019] Allocated by task 187:
> > > [    7.932285] not ok 4 drm_sched_basic_modify_sched_tests
> > > [    7.932486]  kasan_save_stack+0x33/0x60
> > > [    7.932835]     KTAP version 1
> > > [    7.933153]  kasan_save_track+0x14/0x30
> > > [    7.933156]  __kasan_kmalloc+0x8f/0xa0
> > > [    7.933652]     # Subtest: drm_sched_basic_credits_tests
> > > [    7.934095]  __kmalloc_noprof+0x18a/0x440
> > > [    7.934494]     # module: drm_sched_tests
> > > [    7.934817]  kunit_kmalloc_array+0x1b/0x50
> > > [    7.935201]     1..1
> > > [    7.935589]  drm_mock_sched_job_new+0x8f/0x400
> > > [    7.935592]  drm_sched_test_modify_sched+0x1cd/0x490
> > > [    7.950666]  kunit_try_run_case+0x1ae/0x490
> > > [    7.950977]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> > > [    7.951400]  kthread+0x30f/0x620
> > > [    7.951656]  ret_from_fork+0x2f/0x70
> > > [    7.951936]  ret_from_fork_asm+0x1a/0x30
> > > [    7.952250]
> > > [    7.952373] Freed by task 192:
> > > [    7.952605]  kasan_save_stack+0x33/0x60
> > > [    7.952884]  kasan_save_track+0x14/0x30
> > > [    7.953169]  kasan_save_free_info+0x3b/0x60
> > > [    7.953495]  __kasan_slab_free+0x37/0x50
> > > [    7.953797]  kfree+0x12f/0x350
> > > [    7.954035]  kunit_remove_resource+0x130/0x1f0
> > > [    7.954379]  kunit_cleanup+0x6e/0x110
> > > [    7.954656]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> > > [    7.955044]  kthread+0x30f/0x620
> > > [    7.955286]  ret_from_fork+0x2f/0x70
> > > [    7.955557]  ret_from_fork_asm+0x1a/0x30
> > > [    7.955844]
> > > [    7.955956] The buggy address belongs to the object at 
> > > ffff8881092ec800
> > > [    7.955956]  which belongs to the cache kmalloc-512 of size
> > > 512
> > > [    7.956883] The buggy address is located 232 bytes inside of
> > > [    7.956883]  freed 512-byte region [ffff8881092ec800, 
> > > ffff8881092eca00)
> > > [    7.957790]
> > > [    7.957904] The buggy address belongs to the physical page:
> > > [    7.958324] page: refcount:0 mapcount:0
> > > mapping:0000000000000000 
> > > index:0x0 pfn:0x1092e8
> > > [    7.958925] head: order:3 mapcount:0 entire_mapcount:0 
> > > nr_pages_mapped:0 pincount:0
> > > [    7.959527] flags: 0x200000000000040(head|node=0|zone=2)
> > > [    7.959926] page_type: f5(slab)
> > > [    7.960163] raw: 0200000000000040 ffff888100042c80
> > > dead000000000122 
> > > 0000000000000000
> > > [    7.960743] raw: 0000000000000000 0000000080200020
> > > 00000000f5000000 
> > > 0000000000000000
> > > [    7.961304] head: 0200000000000040 ffff888100042c80 
> > > dead000000000122 0000000000000000
> > > [    7.961880] head: 0000000000000000 0000000080200020 
> > > 00000000f5000000 0000000000000000
> > > [    7.962460] head: 0200000000000003 ffffea000424ba01 
> > > ffffffffffffffff 0000000000000000
> > > [    7.963025] head: 0000000000000008 0000000000000000 
> > > 00000000ffffffff 0000000000000000
> > > [    7.963602] page dumped because: kasan: bad access detected
> > > [    7.964001]
> > > [    7.964113] Memory state around the buggy address:
> > > [    7.964481]  ffff8881092ec780: fc fc fc fc fc fc fc fc fc fc
> > > fc fc 
> > > fc fc fc fc
> > > [    7.965007]  ffff8881092ec800: fa fb fb fb fb fb fb fb fb fb
> > > fb fb 
> > > fb fb fb fb
> > > [    7.965576] >ffff8881092ec880: fb fb fb fb fb fb fb fb fb fb
> > > fb fb 
> > > fb fb fb fb
> > > [    
> > > 7.966120]                                                        
> > >    ^
> > > [    7.966625]  ffff8881092ec900: fb fb fb fb fb fb fb fb fb fb
> > > fb fb 
> > > fb fb fb fb
> > > [    7.967199]  ffff8881092ec980: fb fb fb fb fb fb fb fb fb fb
> > > fb fb 
> > > fb fb fb fb
> > > [    7.967734] 
> > > =================================================================
> > > =
> > > [    7.968267] Disabling lock debugging due to kernel taint
> > > [    8.999147]     # drm_sched_test_credits: ASSERTION FAILED at 
> > > drivers/gpu/drm/scheduler/tests/mock_scheduler.c:295
> > > [    8.999147]     Expected list_empty(&sched->base.pending_list)
> > > to 
> > > be true, but is false
> > > [    9.001031]     not ok 1 drm_sched_test_credits
> > > [    9.001034] not ok 5 drm_sched_basic_credits_tests
> > > 
> > > 
> > > 
> > > > 
> > > > > On which commit do you apply and test this series? Tell me,
> > > > > then I
> > > > > test again.
> > > > 
> > > > Depending on the setup, these three:
> > > > 
> > > > commit 413ae464b8021542ad90cb1fbb15f8efc5050a5d
> > > > Author: Thomas Zimmermann <tzimmermann@suse.de>
> > > > Date:   Mon Mar 3 16:41:48 2025 +0100
> > > > 
> > > >       drm-tip: 2025y-03m-03d-15h-40m-53s UTC integration
> > > > manifest
> > > > 
> > > > commit 5bcb67a2a4c61034f5a25c024631c5fbf351ee8d
> > > > Author: Matt Coster <matt.coster@imgtec.com>
> > > > Date:   Wed Feb 26 10:01:09 2025 +0000
> > > > 
> > > >       drm-tip: 2025y-02m-26d-09h-59m-48s UTC integration
> > > > manifest
> > > > 
> > > > commit 777e1850811f9864aa8b55940634d3da19712bf7
> > > > Author: Imre Deak <imre.deak@intel.com>
> > > > Date:   Tue Mar 11 11:31:04 2025 +0200
> > > > 
> > > >       drm-tip: 2025y-03m-11d-09h-30m-13s UTC integration
> > > > manifest
> > > > 
> > > > Regards,
> > > > 
> > > > Tvrtko
> > > > 
> > > > > [    3.902457] Loaded X.509 cert 'sforshee:
> > > > > 00b28ddf47aef9cea7'
> > > > > [    3.903376] Loaded X.509 cert 'wens:
> > > > > 61c038651aabdcf94bd0ac7ff06c7248db18c600'
> > > > > [    3.904064] platform regulatory.0: Direct firmware load
> > > > > for
> > > > > regulatory.db failed with error -2
> > > > > [    3.904673] cfg80211: failed to load regulatory.db
> > > > > [    3.905037] ALSA device list:
> > > > > [    3.905376]   No soundcards found.
> > > > > [    3.905631] KTAP version 1
> > > > > [    3.905834] 1..17
> > > > > [    3.906732]     KTAP version 1
> > > > > [    3.906999]     # Subtest: kunit_executor_test
> > > > > [    3.907335]     # module: kunit
> > > > > [    3.907337]     1..8
> > > > > [    3.908476]     ok 1 parse_filter_test
> > > > > [    3.909064]     ok 2 filter_suites_test
> > > > > [    3.909801]     ok 3 filter_suites_test_glob_test
> > > > > [    3.910678]     ok 4 filter_suites_to_empty_test
> > > > > [    3.911621]     ok 5 parse_filter_attr_test
> > > > > [    3.912641]     ok 6 filter_attr_test
> > > > > [    3.913511]     ok 7 filter_attr_empty_test
> > > > > [    3.914081]     ok 8 filter_attr_skip_test
> > > > > [    3.914400] # kunit_executor_test: pass:8 fail:0 skip:0
> > > > > total:8
> > > > > [    3.914685] # Totals: pass:8 fail:0 skip:0 total:8
> > > > > [    3.915121] ok 1 kunit_executor_test
> > > > > [    3.915736]     KTAP version 1
> > > > > [    3.915949]     # Subtest: kunit-try-catch-test
> > > > > [    3.916314]     # module: kunit_test
> > > > > [    3.916315]     1..2
> > > > > [    3.917655]     ok 1
> > > > > kunit_test_try_catch_successful_try_no_catch
> > > > > [    3.917979]     ok 2
> > > > > kunit_test_try_catch_unsuccessful_try_does_catch
> > > > > [    3.918630] # kunit-try-catch-test: pass:2 fail:0 skip:0
> > > > > total:2
> > > > > [    3.919118] # Totals: pass:2 fail:0 skip:0 total:2
> > > > > [    3.919578] ok 2 kunit-try-catch-test
> > > > > [    3.920248]     KTAP version 1
> > > > > [    3.920473]     # Subtest: kunit-resource-test
> > > > > [    3.920796]     # module: kunit_test
> > > > > [    3.920797]     1..12
> > > > > [    3.921565]     ok 1 kunit_resource_test_init_resources
> > > > > [    3.921793]     ok 2 kunit_resource_test_alloc_resource
> > > > > [    3.922449]     ok 3 kunit_resource_test_destroy_resource
> > > > > [    3.923013]     ok 4 kunit_resource_test_remove_resource
> > > > > [    3.924438]     ok 5 kunit_resource_test_cleanup_resources
> > > > > [    3.925834]     ok 6
> > > > > kunit_resource_test_proper_free_ordering
> > > > > [    3.926700]     ok 7 kunit_resource_test_static
> > > > > [    3.927588]     ok 8 kunit_resource_test_named
> > > > > [    3.928244]     ok 9 kunit_resource_test_action
> > > > > [    3.928774]     ok 10 kunit_resource_test_remove_action
> > > > > [    3.929309]     ok 11 kunit_resource_test_release_action
> > > > > [    3.929826] action_order_2
> > > > > [    3.930325] action_order_2
> > > > > [    3.930521] action_order_1
> > > > > [    3.931007]     ok 12 kunit_resource_test_action_ordering
> > > > > [    3.931308] # kunit-resource-test: pass:12 fail:0 skip:0
> > > > > total:12
> > > > > [    3.931702] # Totals: pass:12 fail:0 skip:0 total:12
> > > > > [    3.932183] ok 3 kunit-resource-test
> > > > > [    3.932809]     KTAP version 1
> > > > > [    3.933040]     # Subtest: kunit-log-test
> > > > > [    3.933367]     # module: kunit_test
> > > > > [    3.933368]     1..2
> > > > > [    3.934030] put this in log.
> > > > > [    3.934033] this too.
> > > > > [    3.934305] add to suite log.
> > > > > [    3.934500] along with this.
> > > > > [    3.934982]     ok 1 kunit_log_test
> > > > > [    3.935405]     # kunit_log_newline_test: Add newline
> > > > > [    3.936164]     ok 2 kunit_log_newline_test # SKIP only
> > > > > useful
> > > > > when debugfs is enabled
> > > > > [    3.936166] # kunit-log-test: pass:1 fail:0 skip:1 total:2
> > > > > [    3.936752] # Totals: pass:1 fail:0 skip:1 total:2
> > > > > [    3.937197] ok 4 kunit-log-test
> > > > > [    3.937776]     KTAP version 1
> > > > > [    3.938004]     # Subtest: kunit_status
> > > > > [    3.938324]     # module: kunit_test
> > > > > [    3.938325]     1..2
> > > > > [    3.938921]     ok 1 kunit_status_set_failure_test
> > > > > [    3.939049]     ok 2 kunit_status_mark_skipped_test
> > > > > [    3.939445] # kunit_status: pass:2 fail:0 skip:0 total:2
> > > > > [    3.939816] # Totals: pass:2 fail:0 skip:0 total:2
> > > > > [    3.940436] ok 5 kunit_status
> > > > > [    3.941142]     KTAP version 1
> > > > > [    3.941508]     # Subtest: kunit_current
> > > > > [    3.941793]     # module: kunit_test
> > > > > [    3.941794]     1..2
> > > > > [    3.942526]     ok 1 kunit_current_test
> > > > > [    3.942596]     # fake test: lib/kunit/kunit-test.c:722:
> > > > > This
> > > > > should make `fake` test fail.
> > > > > [    3.943302]     ok 2 kunit_current_fail_test
> > > > > [    3.943908] # kunit_current: pass:2 fail:0 skip:0 total:2
> > > > > [    3.944271] # Totals: pass:2 fail:0 skip:0 total:2
> > > > > [    3.944661] ok 6 kunit_current
> > > > > [    3.945285]     KTAP version 1
> > > > > [    3.945511]     # Subtest: kunit_device
> > > > > [    3.945789]     # module: kunit_test
> > > > > [    3.945790]     1..3
> > > > > [    3.946905]     ok 1 kunit_device_test
> > > > > [    3.947420]     ok 2 kunit_device_cleanup_test
> > > > > [    3.948621]     ok 3 kunit_device_driver_test
> > > > > [    3.948972] # kunit_device: pass:3 fail:0 skip:0 total:3
> > > > > [    3.949349] # Totals: pass:3 fail:0 skip:0 total:3
> > > > > [    3.949760] ok 7 kunit_device
> > > > > [    3.950395]     KTAP version 1
> > > > > [    3.950617]     # Subtest: kunit_fault
> > > > > [    3.950889]     # module: kunit_test
> > > > > [    3.950890]     1..1
> > > > > [    3.951773] Oops: general protection fault, probably for
> > > > > non-
> > > > > canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP
> > > > > KASAN
> > > > > PTI
> > > > > [    3.952672] KASAN: null-ptr-deref in range
> > > > > [0x0000000000000000-
> > > > > 0x0000000000000007]
> > > > > [    3.953239] CPU: 2 UID: 0 PID: 225 Comm: kunit_try_catch
> > > > > Tainted: G                 N 6.14.0-rc4-00388-g712b7c2f4d5d
> > > > > #21
> > > > > [    3.954000] Tainted: [N]=TEST
> > > > > [    3.954245] Hardware name: QEMU Standard PC (i440FX +
> > > > > PIIX,
> > > > > 1996), BIOS 1.16.3-2.fc40 04/01/2014
> > > > > [    3.954850] RIP:
> > > > > 0010:kunit_test_null_dereference+0x4a/0x150
> > > > > [    3.955285] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1
> > > > > ed 03
> > > > > 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1
> > > > > c7 42
> > > > > 04 01 f3 f3 f3 <0f> b6 04
> > > > > [    3.956604] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
> > > > > [    3.956972] RAX: dffffc0000000000 RBX: ffff88810088fb30
> > > > > RCX:
> > > > > ffffffffb65da11d
> > > > > [    3.957651] RDX: ffffed1021241fc0 RSI: 0000000000000008
> > > > > RDI:
> > > > > ffff88810088fb30
> > > > > [    3.958317] RBP: 1ffff11021241fc0 R08: 0000000000000000
> > > > > R09:
> > > > > ffffed10207de600
> > > > > [    3.958849] R10: ffff888103ef3007 R11: 0000000000000000
> > > > > R12:
> > > > > ffffffffb73baf40
> > > > > [    3.959425] R13: ffffffffb73b1c60 R14: ffff8881038a9d80
> > > > > R15:
> > > > > ffff8881091c6ac0
> > > > > [    3.959917] FS:  0000000000000000(0000)
> > > > > GS:ffff888a88700000(0000) knlGS:0000000000000000
> > > > > [    3.960521] CS:  0010 DS: 0000 ES: 0000 CR0:
> > > > > 0000000080050033
> > > > > [    3.960920] CR2: 0000000000000000 CR3: 0000000b1406a000
> > > > > CR4:
> > > > > 00000000000006f0
> > > > > [    3.961480] Call Trace:
> > > > > [    3.961655]  <TASK>
> > > > > [    3.961805]  ? die_addr+0x3b/0xa0
> > > > > [    3.962052]  ? exc_general_protection+0x151/0x220
> > > > > [    3.962439]  ? asm_exc_general_protection+0x26/0x30
> > > > > [    3.962801]  ?
> > > > > __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
> > > > > [    3.963447]  ? __pfx_kunit_test_null_dereference+0x10/0x10
> > > > > [    3.964150]  ? __kthread_parkme+0x7d/0x140
> > > > > [    3.964443]  ? kunit_test_null_dereference+0x4a/0x150
> > > > > [    3.964785]  ? __pfx_kunit_test_null_dereference+0x10/0x10
> > > > > [    3.965205]  ? __kthread_parkme+0x7d/0x140
> > > > > [    3.965494]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> > > > > [    3.965859]  kthread+0x30f/0x620
> > > > > [    3.966108]  ? __pfx_kthread+0x10/0x10
> > > > > [    3.966406]  ? __pfx_kthread+0x10/0x10
> > > > > [    3.966680]  ret_from_fork+0x2f/0x70
> > > > > [    3.966941]  ? __pfx_kthread+0x10/0x10
> > > > > [    3.967264]  ret_from_fork_asm+0x1a/0x30
> > > > > [    3.967560]  </TASK>
> > > > > [    3.967722] Modules linked in:
> > > > > [    3.967989] ---[ end trace 0000000000000000 ]---
> > > > > [    3.968368] RIP:
> > > > > 0010:kunit_test_null_dereference+0x4a/0x150
> > > > > [    3.968780] Code: b5 41 48 c7 44 24 08 98 95 51 ba 48 c1
> > > > > ed 03
> > > > > 48 c7 44 24 10 40 af 3b b7 48 8d 54 05 00 c7 02 f1 f1 f1 f1
> > > > > c7 42
> > > > > 04 01 f3 f3 f3 <0f> b6 04
> > > > > [    3.970211] RSP: 0000:ffff88810920fe00 EFLAGS: 00010a06
> > > > > [    3.970567] RAX: dffffc0000000000 RBX: ffff88810088fb30
> > > > > RCX:
> > > > > ffffffffb65da11d
> > > > > [    3.971074] RDX: ffffed1021241fc0 RSI: 0000000000000008
> > > > > RDI:
> > > > > ffff88810088fb30
> > > > > [    3.971580] RBP: 1ffff11021241fc0 R08: 0000000000000000
> > > > > R09:
> > > > > ffffed10207de600
> > > > > [    3.972089] R10: ffff888103ef3007 R11: 0000000000000000
> > > > > R12:
> > > > > ffffffffb73baf40
> > > > > [    3.972629] R13: ffffffffb73b1c60 R14: ffff8881038a9d80
> > > > > R15:
> > > > > ffff8881091c6ac0
> > > > > [    3.973176] FS:  0000000000000000(0000)
> > > > > GS:ffff888a88700000(0000) knlGS:0000000000000000
> > > > > [    3.973720] CS:  0010 DS: 0000 ES: 0000 CR0:
> > > > > 0000000080050033
> > > > > [    3.974148] CR2: 0000000000000000 CR3: 0000000b1406a000
> > > > > CR4:
> > > > > 00000000000006f0
> > > > > [    3.974659] kunit_try_catch (225) used greatest stack
> > > > > depth:
> > > > > 28416 bytes left
> > > > > [    3.974764]     # kunit_test_fault_null_dereference: try
> > > > > faulted: last line seen lib/kunit/kunit-test.c:95
> > > > > [    3.976367]     ok 1 kunit_test_fault_null_dereference
> > > > > [    3.976370] ok 8 kunit_fault
> > > > > [    3.976946]     KTAP version 1
> > > > > [    3.977208]     # Subtest: kunit_platform_device
> > > > > [    3.977549]     # module: platform_test
> > > > > [    3.977550]     1..4
> > > > > [    3.978550]     ok 1 kunit_platform_device_alloc_test
> > > > > [    3.978989]     ok 2 kunit_platform_device_add_test
> > > > > [    3.980097] sysfs: cannot create duplicate filename
> > > > > '/devices/platform/kunit-platform-add-2'
> > > > > [    3.981138] CPU: 7 UID: 0 PID: 231 Comm: kunit_try_catch
> > > > > Tainted: G      D          N 6.14.0-rc4-00388-g712b7c2f4d5d
> > > > > #21
> > > > > [    3.981142] Tainted: [D]=DIE, [N]=TEST
> > > > > [    3.981143] Hardware name: QEMU Standard PC (i440FX +
> > > > > PIIX,
> > > > > 1996), BIOS 1.16.3-2.fc40 04/01/2014
> > > > > [    3.981144] Call Trace:
> > > > > [    3.981145]  <TASK>
> > > > > [    3.981146]  dump_stack_lvl+0x53/0x70
> > > > > [    3.981151]  sysfs_warn_dup+0x70/0x90
> > > > > [    3.981154]  sysfs_create_dir_ns+0x209/0x280
> > > > > [    3.981156]  ? __pfx_sysfs_create_dir_ns+0x10/0x10
> > > > > [    3.981159]  ? _raw_spin_lock+0x80/0xe0
> > > > > [    3.981161]  kobject_add_internal+0x216/0x8b0
> > > > > [    3.981163]  kobject_add+0x13b/0x200
> > > > > [    3.981165]  ? __pfx_kobject_add+0x10/0x10
> > > > > [    3.981167]  ? kobject_get+0x50/0xe0
> > > > > [    3.981169]  device_add+0x217/0x1460
> > > > > [    3.981171]  ? __pfx_device_add+0x10/0x10
> > > > > [    3.981173]  ? _raw_spin_lock_irqsave+0x86/0xe0
> > > > > [    3.981174]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> > > > > [    3.981176]  ? device_initialize+0x1f4/0x410
> > > > > [    3.981179]  ? platform_device_alloc+0x97/0x200
> > > > > [    3.981182]  platform_device_add+0x375/0x5b0
> > > > > [    3.981184]  kunit_platform_device_add+0x20/0x2c0
> > > > > [    3.981186]
> > > > > kunit_platform_device_add_twice_fails_test+0x1f5/0x420
> > > > > [    3.981189]  ?
> > > > > __pfx_kunit_platform_device_add_twice_fails_test+0x10/0x10
> > > > > [    3.981191]  ? __schedule+0xdda/0x24f0
> > > > > [    3.981193]  ? kvm_clock_get_cycles+0x18/0x30
> > > > > [    3.981196]  ? ktime_get_ts64+0x7d/0x220
> > > > > [    3.981200]  kunit_try_run_case+0x1ae/0x490
> > > > > [    3.981202]  ? __pfx_kunit_try_run_case+0x10/0x10
> > > > > [    3.981204]  ? _raw_spin_lock_irqsave+0x86/0xe0
> > > > > [    3.981205]  ? __pfx_kunit_try_run_case+0x10/0x10
> > > > > [    3.981207]  ?
> > > > > __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
> > > > > [    3.981210]  kunit_generic_run_threadfn_adapter+0x7b/0xe0
> > > > > [    3.981212]  kthread+0x30f/0x620
> > > > > [    3.981214]  ? __pfx_kthread+0x10/0x10
> > > > > [    3.981216]  ? __pfx_kthread+0x10/0x10
> > > > > [    3.981217]  ret_from_fork+0x2f/0x70
> > > > > [    3.981223]  ? __pfx_kthread+0x10/0x10
> > > > > [    3.981225]  ret_from_fork_asm+0x1a/0x30
> > > > > [    3.981227]  </TASK>
> > > > > [    3.981232] kobject: kobject_add_internal failed for
> > > > > kunit-
> > > > > platform-add-2 with -EEXIST, don't try to register things
> > > > > with the
> > > > > same name in the same direc.
> > > > > [    3.995255] kunit_try_catch (231) used greatest stack
> > > > > depth:
> > > > > 27528 bytes left
> > > > > [    3.995525]     ok 3
> > > > > kunit_platform_device_add_twice_fails_test
> > > > > [    3.996247]     ok 4 kunit_platform_device_add_cleans_up
> > > > > [    3.996678] # kunit_platform_device: pass:4 fail:0 skip:0
> > > > > total:4
> > > > > [    3.997073] # Totals: pass:4 fail:0 skip:0 total:4
> > > > > [    3.997530] ok 9 kunit_platform_device
> > > > > [    3.998130]     KTAP version 1
> > > > > [    3.998356]     # Subtest: kunit_platform_driver
> > > > > [    3.998664]     # module: platform_test
> > > > > [    3.998665]     1..2
> > > > > [    3.999663]     ok 1 kunit_platform_driver_register_test
> > > > > [    4.000372]     ok 2
> > > > > kunit_platform_device_prepare_wait_for_probe_completes_when_a
> > > > > lready
> > > > > _probed
> > > > > [    4.000750] # kunit_platform_driver: pass:2 fail:0 skip:0
> > > > > total:2
> > > > > [    4.001372] # Totals: pass:2 fail:0 skip:0 total:2
> > > > > [    4.001777] ok 10 kunit_platform_driver
> > > > > [    4.002412]     KTAP version 1
> > > > > [    4.002618]     # Subtest: string-stream-test
> > > > > [    4.002909]     # module: string_stream_test
> > > > > [    4.002910]     1..12
> > > > > [    4.003643]     ok 1 string_stream_managed_init_test
> > > > > [    4.003919]     ok 2 string_stream_unmanaged_init_test
> > > > > [    4.004581]     ok 3 string_stream_managed_free_test
> > > > > [    4.005295]     ok 4 string_stream_resource_free_test
> > > > > [    4.007076]     ok 5 string_stream_line_add_test
> > > > > [    4.008801]     ok 6
> > > > > string_stream_variable_length_line_test
> > > > > [    4.009944]     ok 7 string_stream_append_test
> > > > > [    4.010840]     ok 8
> > > > > string_stream_append_auto_newline_test
> > > > > [    4.011461]     ok 9
> > > > > string_stream_append_empty_string_test
> > > > > [    4.012233]     ok 10 string_stream_no_auto_newline_test
> > > > > [    4.013158]     ok 11 string_stream_auto_newline_test
> > > > > [    4.063760]     # string_stream_performance_test: Time
> > > > > elapsed:           49385 us
> > > > > [    4.064713]     # string_stream_performance_test: Total
> > > > > string
> > > > > length:    573890
> > > > > [    4.065271]     # string_stream_performance_test: Bytes
> > > > > requested:        823930
> > > > > [    4.065803]     # string_stream_performance_test: Actual
> > > > > bytes
> > > > > allocated: 1048312
> > > > > [    4.098820]     ok 12 string_stream_performance_test
> > > > > [    4.098826] # string-stream-test: pass:12 fail:0 skip:0
> > > > > total:12
> > > > > [    4.099348] # Totals: pass:12 fail:0 skip:0 total:12
> > > > > [    4.099814] ok 11 string-stream-test
> > > > > [    4.100495]     KTAP version 1
> > > > > [    4.100735]     # Subtest: kunit-assert
> > > > > [    4.101048]     # module: assert_test
> > > > > [    4.101050]     1..11
> > > > > [    4.101943]     ok 1 kunit_test_is_literal
> > > > > [    4.102331]     ok 2 kunit_test_is_str_literal
> > > > > [    4.103177]     ok 3 kunit_test_assert_prologue
> > > > > [    4.103996]     ok 4 kunit_test_assert_print_msg
> > > > > [    4.104867]     ok 5 kunit_test_unary_assert_format
> > > > > [    4.105908]     ok 6 kunit_test_ptr_not_err_assert_format
> > > > > [    4.107022]     ok 7 kunit_test_binary_assert_format
> > > > > [    4.107868]     ok 8 kunit_test_binary_ptr_assert_format
> > > > > [    4.108702]     ok 9 kunit_test_binary_str_assert_format
> > > > > [    4.109969]     ok 10 kunit_test_assert_hexdump
> > > > > [    4.111490]     ok 11 kunit_test_mem_assert_format
> > > > > [    4.111845] # kunit-assert: pass:11 fail:0 skip:0 total:11
> > > > > [    4.112522] # Totals: pass:11 fail:0 skip:0 total:11
> > > > > [    4.112949] ok 12 kunit-assert
> > > > > [    4.113628]     KTAP version 1
> > > > > [    4.113867]     # Subtest: drm_sched_basic_tests
> > > > > [    4.114281]     # module: drm_sched_tests
> > > > > [    4.114283]     1..3
> > > > > [    4.234223] input: ImExPS/2 Generic Explorer Mouse as
> > > > > /devices/platform/i8042/serio1/input/input3
> > > > > [    4.617191]     ok 1 drm_sched_basic_submit
> > > > > [    4.617197]         KTAP version 1
> > > > > [    4.617765]         # Subtest: drm_sched_basic_test
> > > > > [    4.719657]         ok 1 A queue of jobs in a single
> > > > > entity
> > > > > [    4.821976]         ok 2 A chain of dependent jobs across
> > > > > multiple entities
> > > > > [    4.924015]         ok 3 Multiple independent job queues
> > > > > [    5.026465]         ok 4 Multiple inter-dependent job
> > > > > queues
> > > > > [    5.026907]     # drm_sched_basic_test: pass:4 fail:0
> > > > > skip:0
> > > > > total:4
> > > > > [    5.027322]     ok 2 drm_sched_basic_test
> > > > > [    5.080020]     ok 3 drm_sched_basic_entity_cleanup
> > > > > [    5.080317] # drm_sched_basic_tests: pass:3 fail:0 skip:0
> > > > > total:3
> > > > > [    5.080657] # Totals: pass:6 fail:0 skip:0 total:6
> > > > > [    5.081103] ok 13 drm_sched_basic_tests
> > > > > [    5.081679]     KTAP version 1
> > > > > [    5.081881]     # Subtest: drm_sched_basic_timeout_tests
> > > > > [    5.082259]     # module: drm_sched_tests
> > > > > [    5.082260]     1..1
> > > > > 
> > > > > 
> > > > > 
> > > > > > 
> > > > > > Cc: Christian König <christian.koenig@amd.com>
> > > > > > Cc: Danilo Krummrich <dakr@kernel.org>
> > > > > > Cc: Matthew Brost <matthew.brost@intel.com>
> > > > > > Cc: Philipp Stanner <phasta@kernel.org>
> > > > > > 
> > > > > > Tvrtko Ursulin (7):
> > > > > >     drm: Move some options to separate new Kconfig
> > > > > >     drm/sched: Add scheduler unit testing infrastructure
> > > > > > and some
> > > > > > basic
> > > > > >       tests
> > > > > >     drm/sched: Add aspirational unit test mode
> > > > > >     drm/sched: Add a simple timeout test
> > > > > >     drm/sched: Add basic priority tests
> > > > > >     drm/sched: Add a basic test for modifying entities
> > > > > > scheduler
> > > > > > list
> > > > > >     drm/sched: Add a basic test for checking credit limit
> > > > > > 
> > > > > >    drivers/gpu/drm/Kconfig                       | 109 +---
> > > > > >    drivers/gpu/drm/Kconfig.debug                 | 128
> > > > > > +++++
> > > > > >    drivers/gpu/drm/scheduler/.kunitconfig        |  12 +
> > > > > >    drivers/gpu/drm/scheduler/Makefile            |   2 +
> > > > > >    drivers/gpu/drm/scheduler/tests/Makefile      |   7 +
> > > > > >    .../gpu/drm/scheduler/tests/mock_scheduler.c  | 345
> > > > > > +++++++++++++
> > > > > >    drivers/gpu/drm/scheduler/tests/sched_tests.h | 224
> > > > > > +++++++++
> > > > > >    drivers/gpu/drm/scheduler/tests/tests_basic.c | 476
> > > > > > ++++++++++++++++++
> > > > > >    8 files changed, 1199 insertions(+), 104 deletions(-)
> > > > > >    create mode 100644 drivers/gpu/drm/Kconfig.debug
> > > > > >    create mode 100644
> > > > > > drivers/gpu/drm/scheduler/.kunitconfig
> > > > > >    create mode 100644
> > > > > > drivers/gpu/drm/scheduler/tests/Makefile
> > > > > >    create mode 100644
> > > > > > drivers/gpu/drm/scheduler/tests/mock_scheduler.c
> > > > > >    create mode 100644
> > > > > > drivers/gpu/drm/scheduler/tests/sched_tests.h
> > > > > >    create mode 100644
> > > > > > drivers/gpu/drm/scheduler/tests/tests_basic.c
> > > > > > 
> > > > > 
> > > > 
> > > 
> > 
>
Tvrtko Ursulin March 12, 2025, 2:33 p.m. UTC | #7
On 12/03/2025 13:49, Philipp Stanner wrote:

[snip]

>>>> There I see a UAF. Do you have an idea what that might be? I
>>>> would only
>>>> expect memory leaks and the test assertions failing.
>>>
>>> It is expected all hell to break loose in aspirational mode. There
>>> the
>>> mock scheduler shutdown relies solely on drm_sched_fini. So all
>>> tests
>>> which do not fully idle the mock scheduler themselves, whether
>>> implicity
>>> or explicitly, will explode in various ways.
>>
>> To clarify I made it like that because that is what I understood was
>> your vision for drm_sched_fini. That it would be able to clean
>> everything up etc.
>>
>> If you meant something different we need to adjust it. Although it
>> could
>> be done later as well.
> 
> My primary intention was to use those tests to see whether my memory
> leak fix works or not.

Okay here I don't know exactly what are you changing and how you are 
testing to comment.

> Thus I'd need something like in v4, where the tests run as intended but
> leak the jobs in the pending_list. Would indeed be neat if they also
> check for list_len(pending_list) so that you don't have to run kmemleak
> manually.
> 
> And since we shouldn't have such leaks in production tests the idea of
> optionally enabling them arose.
> 
> More generally speaking, I think that the tests should behave as we
> expect drivers to behave *currently*, while we have the option for the
> tests to purposefully misbehave. In my case this means: just leak the
> jobs and optionally tell about the leaks.
> 
> When used as intended, the scheduler currently AFAIK doesn't have UAF
> or nullptrderefs, so they shouldn't occur in tests that use it as
> intended. Now the leaks are special because we never intended them.
> 
> So what surprised me is that, when compared to v4, this v7 here
> actually now also has UAF. Besides not cleaning up leaks, what are you
> doing in aspiritional mode?
> 
> Let's talk it through before you invest your time into v8

1)

"Normal" mode is fine, do you agree? No leaks, no UAF. Ie. it is 
exercising the scheduler how drivers are supposed to use it today.

2)

Aspirational mode I added on your request and you can define how you 
want it to work.

Lets have a look in drm_mock_sched_fini() and see that it is pretty 
straightforward. First I'll pre-process and annotate the normal version:

void drm_mock_sched_fini(struct drm_mock_scheduler *sched)
{
	struct drm_mock_sched_job *job, *next;
	struct kunit  *test = sched->test;
	unsigned long flags;
	LIST_HEAD(signal);

	// Stop the scheduler workqueues so nothing further gets scheduled
	drm_sched_wqueue_stop(&sched->base);

	// Idle the mock scheduler in-flight jobs:

	// First move them to a local list so any in parallel "hardware" 
activity does not see them any more

	spin_lock_irqsave(&sched->lock, flags);
	list_for_each_entry_safe(job, next, &sched->job_list, link)
		list_move_tail(&job->link, &signal);
	spin_unlock_irqrestore(&sched->lock, flags);

	// Now for jobs which "hardware" hasn't processed yet we do:
	//
	// 1. Cancel the completion timer
	// 2. Mark the job as complete (signal the hw fence, wake up waiters)
	// 3. Release the hardware fence (list had a reference)
	// 4. Free the job itself

	list_for_each_entry(job, &signal, link) {
		hrtimer_cancel(&job->timer);
		drm_mock_sched_job_complete(job);
		dma_fence_put(&job->hw_fence);
		drm_sched_job_cleanup(&job->base);
	}

	// Finally drm_sched_fini
	drm_sched_fini(&sched->base);
}

In aspirational mode it becomes this:

void drm_mock_sched_fini(struct drm_mock_scheduler *sched)
{
	struct kunit  *test = sched->test;

	drm_sched_fini(&sched->base);

	KUNIT_ASSERT_TRUE(test, list_empty(&sched->job_list));
	KUNIT_ASSERT_TRUE(test, list_empty(&sched->base.pending_list));
}

So relies on drm_sched_fini to cleanup _everything_. Including the 
driver (mock scheduler) state. Which is what I understood you wanted.

For example drm_sched_basic_entity_cleanup test case will exit (kill the 
entities and tear down the scheduler) with half of the submitted jobs 
still in flight. That's one example of what will be caught here by the 
asserts and also UAF since kunit test will just exit and free up memory 
regardless.

If this isn't what you had in mind you can either a) tell me what you 
want maybe I can tweak it*, or b) we can drop the aspirational patch for 
now.

*)
For example it would be possible to avoid UAFs by moving away from kunit 
managed allocations and just leak memory. Plus, it would also be 
required to cancel the timers or so.

For running in the VM or UML cases, which I thought were typical, it 
wouldn't be a benefit, but if you are worried about running on the host 
kernel and expect no crashes, then that aspect would need to change.

Regards,

Tvrtko