On 2022-07-05 14:48, Felix Kuehling
wrote:
On 2022-06-10 21:03, Philip Yang wrote:
If destroying/unmapping queue failed, application may destroy queue
again, cause below kernel warning backtrace.
For outstanding queues, either applications forget to destroy or failed
to destroy, kfd_process_notifier_release will remove queue sysfs
objects, kfd_process_wq_release will free queue doorbell.
refcount_t: underflow; use-after-free.
WARNING: CPU: 7 PID: 3053 at lib/refcount.c:28
Call Trace:
kobject_put+0xd6/0x1a0
kfd_procfs_del_queue+0x27/0x30 [amdgpu]
pqm_destroy_queue+0xeb/0x240 [amdgpu]
kfd_ioctl_destroy_queue+0x32/0x70 [amdgpu]
kfd_ioctl+0x27d/0x500 [amdgpu]
do_syscall_64+0x35/0x80
WARNING: CPU: 2 PID: 3053 at drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device_queue_manager.c:400
Call Trace:
deallocate_doorbell.isra.0+0x39/0x40 [amdgpu]
destroy_queue_cpsch+0xb3/0x270 [amdgpu]
pqm_destroy_queue+0x108/0x240 [amdgpu]
kfd_ioctl_destroy_queue+0x32/0x70 [amdgpu]
kfd_ioctl+0x27d/0x500 [amdgpu]
Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 4 ++--
drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index e1797657b04c..1c519514ca1a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1876,8 +1876,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
mqd_mgr = dqm->mqd_mgrs[get_mqd_type_from_queue_type(
q->properties.type)];
- deallocate_doorbell(qpd, q);
-
if ((q->properties.type == KFD_QUEUE_TYPE_SDMA) ||
(q->properties.type == KFD_QUEUE_TYPE_SDMA_XGMI)) {
deallocate_sdma_queue(dqm, q);
@@ -1898,6 +1896,8 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
}
}
+ deallocate_doorbell(qpd, q);
+
I'm not sure what this change is meant to do. I don't see an early return in this function, so deallocate_doorbell will always be executed either way.
If app destroy queue deallocate_doorbell, but then unmap queue failed, app will destroy queue again when app exit, deallocate_doorbell second time will trigger the WARN backtrace.
As queue_count and q->list is used to alloc ring buf in execute_queues_cpsch, so this change causes regression on gfx9, I will submit new patch to handle unmap failed case with MES and fix those issues.
Regards,
Philip
/*
* Unconditionally decrement this counter, regardless of the queue's
* type
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
index dc00484ff484..99f2a6412201 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
@@ -419,7 +419,6 @@ int pqm_destroy_queue(struct process_queue_manager *pqm, unsigned int qid)
}
if (pqn->q) {
- kfd_procfs_del_queue(pqn->q);
dqm = pqn->q->device->dqm;
retval = dqm->ops.destroy_queue(dqm, &pdd->qpd, pqn->q);
if (retval) {
@@ -439,6 +438,7 @@ int pqm_destroy_queue(struct process_queue_manager *pqm, unsigned int qid)
if (dev->shared_resources.enable_mes)
amdgpu_amdkfd_free_gtt_mem(dev->adev,
pqn->q->gang_ctx_bo);
+ kfd_procfs_del_queue(pqn->q);
This part makes sense.
Regards,
Felix
uninit_queue(pqn->q);
}
