On 1/21/2024 5:49 AM, vitaly.prosyak@xxxxxxx wrote: > From: Vitaly Prosyak <vitaly.prosyak@xxxxxxx> > > The issue started to appear after the following commit > 11b3b9f461c5c4f700f6c8da202fcc2fd6418e1f (scheduler to variable number > of run-queues). The scheduler flag ready (ring->sched.ready) could not be > used to validate multiple scenarios, for example, check job is running, > gpu_reset, PCI errors etc. The reason is that after GPU reset, the flag > is set to true unconditionally even for those rings with an uninitialized scheduler. > As a result, we called drm_sched_stop, drm_sched_start for the uninitialized > schedule and NULL pointer dereference is occured. For example, the following > occurs on Navi10 during GPU reset: > > [ 354.231044] Hardware name: TYAN B8021G88V2HR-2T/S8021GM2NR-2T, BIOS V1.03.B10 04/01/2019 > [ 354.239152] Workqueue: amdgpu-reset-dev drm_sched_job_timedout [gpu_sched] > [ 354.246047] RIP: 0010:__flush_work.isra.0+0x23a/0x250 > [ 354.251110] Code: 8b 04 25 40 2e 03 00 48 89 44 24 40 48 8b 73 40 8b 4b 30 e9 f9 fe ff ff 40 30 f6 4c 8b 36 e9 37 fe ff ff 0f 0b e9 3a ff ff ff <0f> 0b e9 33 ff ff ff 66 > 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 > [ 354.269876] RSP: 0018:ffffb234c00e3c20 EFLAGS: 00010246 > [ 354.275121] RAX: 0000000000000011 RBX: ffff9796d9796de0 RCX: 0000000000000000 > [ 354.282271] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9796d9796de0 > [ 354.289420] RBP: ffff9796d9796de0 R08: ffff977780401940 R09: ffffffffa1a5c620 > [ 354.296570] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > [ 354.303720] R13: 0000000000000001 R14: ffff9796d97905c8 R15: ffff9796d9790230 > [ 354.310868] FS: 0000000000000000(0000) GS:ffff97865f040000(0000) knlGS:0000000000000000 > [ 354.318963] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 354.324717] CR2: 00007fd5341fca50 CR3: 0000002c27a22000 CR4: 00000000003506f0 > [ 354.324717] CR2: 00007fd5341fca50 CR3: 0000002c27a22000 CR4: 00000000003506f0 > [ 354.331859] Call Trace: > [ 354.334320] <TASK> > [ 354.336433] ? __flush_work.isra.0+0x23a/0x250 > [ 354.340891] ? __warn+0x81/0x130 > [ 354.344139] ? __flush_work.isra.0+0x23a/0x250 > [ 354.348594] ? report_bug+0x171/0x1a0 > [ 354.352279] ? handle_bug+0x3c/0x80 > [ 354.355787] ? exc_invalid_op+0x17/0x70 > [ 354.359635] ? asm_exc_invalid_op+0x1a/0x20 > [ 354.363844] ? __flush_work.isra.0+0x23a/0x250 > [ 354.368307] ? srso_return_thunk+0x5/0x5f > [ 354.372331] ? srso_return_thunk+0x5/0x5f > [ 354.376351] ? desc_read_finalized_seq+0x1f/0x70 > [ 354.380982] ? srso_return_thunk+0x5/0x5f > [ 354.385011] ? _prb_read_valid+0x20e/0x280 > [ 354.389130] __cancel_work_timer+0xd3/0x160 > [ 354.393333] drm_sched_stop+0x46/0x1f0 [gpu_sched] > [ 354.398143] amdgpu_device_gpu_recover+0x318/0xca0 [amdgpu] > [ 354.403995] ? __drm_err+0x1/0x70 [drm] > [ 354.407884] amdgpu_job_timedout+0x151/0x240 [amdgpu] > [ 354.413279] drm_sched_job_timedout+0x76/0x100 [gpu_sched] > [ 354.418787] process_one_work+0x174/0x340 > [ 354.422816] worker_thread+0x27b/0x3a0 > [ 354.426586] ? __pfx_worker_thread+0x10/0x10 > [ 354.430874] kthread+0xe8/0x120 > [ 354.434030] ? __pfx_kthread+0x10/0x10 > [ 354.437790] ret_from_fork+0x34/0x50 > [ 354.441377] ? __pfx_kthread+0x10/0x10 > [ 354.445139] ret_from_fork_asm+0x1b/0x30 > [ 354.449079] </TASK> > [ 354.451285] ---[ end trace 0000000000000000 ]--- > [ 354.455917] BUG: kernel NULL pointer dereference, address: 0000000000000008 > [ 354.462883] #PF: supervisor read access in kernel mode > [ 354.468029] #PF: error_code(0x0000) - not-present page > [ 354.473167] PGD 0 P4D 0 > [ 354.475705] Oops: 0000 [#1] PREEMPT SMP NOPTI > [ 354.480066] CPU: 1 PID: 11 Comm: kworker/u64:0 Tainted: G W 6.7.0-991912.1.zuul.e7596ab24dae4bb686e58b0f1e7842da #1 > [ 354.491883] Hardware name: TYAN B8021G88V2HR-2T/S8021GM2NR-2T, BIOS V1.03.B10 04/01/2019 > [ 354.499976] Workqueue: amdgpu-reset-dev drm_sched_job_timedout [gpu_sched] > [ 354.506855] RIP: 0010:drm_sched_stop+0x61/0x1f0 [gpu_sched] > > The solution is every place where we check the ready flag and check > for ring->no_scheduler. The ready flag serves the purpose in case an initialization > is failed, like starting the worker thread, etc. > > Cc: Alex Deucher <alexander.deucher@xxxxxxx> > Cc: Christian Koenig <christian.koenig@xxxxxxx> > Signed-off-by: Vitaly Prosyak <vitaly.prosyak@xxxxxxx> > --- > .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c | 2 ++ > drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 6 +++--- > drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 14 ++++++++------ > 3 files changed, 13 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c > index 899e31e3a5e8..70bbf602df34 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c > @@ -292,6 +292,8 @@ static int suspend_resume_compute_scheduler(struct amdgpu_device *adev, bool sus > > if (!(ring && drm_sched_wqueue_ready(&ring->sched))) > continue; > + if (ring->no_scheduler) > + continue; > There was a similar patch before - https://lore.kernel.org/all/7cd37500-8633-4030-aae3-9b532d60b501@xxxxxxx/T/#t It introduces amdgpu_ring_sched_ready() to cover the above checks. Thanks, Lijo > /* stop secheduler and drain ring. */ > if (suspend) { > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c > index e485dd3357c6..35132aa2c0f4 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c > @@ -1678,7 +1678,7 @@ static int amdgpu_debugfs_test_ib_show(struct seq_file *m, void *unused) > for (i = 0; i < AMDGPU_MAX_RINGS; i++) { > struct amdgpu_ring *ring = adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > drm_sched_wqueue_stop(&ring->sched); > } > @@ -1694,7 +1694,7 @@ static int amdgpu_debugfs_test_ib_show(struct seq_file *m, void *unused) > for (i = 0; i < AMDGPU_MAX_RINGS; i++) { > struct amdgpu_ring *ring = adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > drm_sched_wqueue_start(&ring->sched); > } > @@ -1916,7 +1916,7 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val) > > ring = adev->rings[val]; > > - if (!ring || !ring->funcs->preempt_ib || > + if (!ring || !ring->funcs->preempt_ib || ring->no_scheduler || > !drm_sched_wqueue_ready(&ring->sched)) > return -EINVAL; > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > index 2df14f0e79d8..894b657df1d3 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > @@ -5052,7 +5052,7 @@ bool amdgpu_device_has_job_running(struct amdgpu_device *adev) > for (i = 0; i < AMDGPU_MAX_RINGS; ++i) { > struct amdgpu_ring *ring = adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > > spin_lock(&ring->sched.job_list_lock); > @@ -5191,8 +5191,10 @@ int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev, > for (i = 0; i < AMDGPU_MAX_RINGS; ++i) { > struct amdgpu_ring *ring = adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > + if (ring->no_scheduler) > + continue; > > /* Clear job fence from fence drv to avoid force_completion > * leave NULL and vm flush fence in fence drv > @@ -5658,7 +5660,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, > for (i = 0; i < AMDGPU_MAX_RINGS; ++i) { > struct amdgpu_ring *ring = tmp_adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > > drm_sched_stop(&ring->sched, job ? &job->base : NULL); > @@ -5727,7 +5729,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, > for (i = 0; i < AMDGPU_MAX_RINGS; ++i) { > struct amdgpu_ring *ring = tmp_adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > > drm_sched_start(&ring->sched, true); > @@ -6082,7 +6084,7 @@ pci_ers_result_t amdgpu_pci_error_detected(struct pci_dev *pdev, pci_channel_sta > for (i = 0; i < AMDGPU_MAX_RINGS; ++i) { > struct amdgpu_ring *ring = adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > > drm_sched_stop(&ring->sched, NULL); > @@ -6224,7 +6226,7 @@ void amdgpu_pci_resume(struct pci_dev *pdev) > for (i = 0; i < AMDGPU_MAX_RINGS; ++i) { > struct amdgpu_ring *ring = adev->rings[i]; > > - if (!ring || !drm_sched_wqueue_ready(&ring->sched)) > + if (!ring || ring->no_scheduler || !drm_sched_wqueue_ready(&ring->sched)) > continue; > > drm_sched_start(&ring->sched, true);
