Commit 2d274bf7 authored by Shane Xiao's avatar Shane Xiao Committed by Alex Deucher
Browse files

amd/amdkfd: Trigger segfault for early userptr unmmapping 



If applications unmap the memory before destroying the userptr, it needs
trigger a segfault to notify user space to correct the free sequence in
VM debug mode.

v2: Send gpu access fault to user space
v3: Report gpu address to user space, remove unnecessary params
v4: update pr_err into one line, remove userptr log info

Signed-off-by: default avatarShane Xiao <shane.xiao@amd.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 8e320f67

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c

+12 −0
Original line number Diff line number Diff line
@@ -2559,6 +2559,18 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info, 
			if (ret != -EFAULT)

				return ret;



			/* If applications unmap memory before destroying the userptr

			 * from the KFD, trigger a segmentation fault in VM debug mode.

			 */

			if (amdgpu_ttm_adev(bo->tbo.bdev)->debug_vm_userptr) {

				pr_err("Pid %d unmapped memory before destroying userptr at GPU addr 0x%llx\n",

								pid_nr(process_info->pid), mem->va);



				// Send GPU VM fault to user space

				kfd_signal_vm_fault_event_with_userptr(kfd_lookup_process_by_pid(process_info->pid),

								mem->va);

			}



			ret = 0;

		}

drivers/gpu/drm/amd/amdkfd/kfd_events.c

+19 −0
Original line number Diff line number Diff line
@@ -1177,6 +1177,25 @@ void kfd_signal_hw_exception_event(u32 pasid) 
	kfd_unref_process(p);

}



void kfd_signal_vm_fault_event_with_userptr(struct kfd_process *p, uint64_t gpu_va)

{

	struct kfd_process_device *pdd;

	struct kfd_hsa_memory_exception_data exception_data;

	int i;



	memset(&exception_data, 0, sizeof(exception_data));

	exception_data.va = gpu_va;

	exception_data.failure.NotPresent = 1;



	// Send VM seg fault to all kfd process device

	for (i = 0; i < p->n_pdds; i++) {

		pdd = p->pdds[i];

		exception_data.gpu_id = pdd->user_gpu_id;

		kfd_evict_process_device(pdd);

		kfd_signal_vm_fault_event(pdd, NULL, &exception_data);

	}

}



void kfd_signal_vm_fault_event(struct kfd_process_device *pdd,

				struct kfd_vm_fault_info *info,

				struct kfd_hsa_memory_exception_data *data)

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

+2 −0
Original line number Diff line number Diff line
@@ -1507,6 +1507,8 @@ int kfd_event_create(struct file *devkfd, struct kfd_process *p, 
int kfd_get_num_events(struct kfd_process *p);

int kfd_event_destroy(struct kfd_process *p, uint32_t event_id);



void kfd_signal_vm_fault_event_with_userptr(struct kfd_process *p, uint64_t gpu_va);



void kfd_signal_vm_fault_event(struct kfd_process_device *pdd,

				struct kfd_vm_fault_info *info,

				struct kfd_hsa_memory_exception_data *data);