Commit 58e6fc2f authored by Philip Yang's avatar Philip Yang Committed by Alex Deucher
Browse files

drm/amdkfd: Fix kfd process ref leaking when userptr unmapping 



kfd_lookup_process_by_pid hold the kfd process reference to ensure it
doesn't get destroyed while sending the segfault event to user space.

Calling kfd_lookup_process_by_pid as function parameter leaks the kfd
process refcount and miss the NULL pointer check if app process is
already destroyed.

Fixes: 2d274bf7 ("amd/amdkfd: Trigger segfault for early userptr unmmapping")
Signed-off-by: default avatarPhilip Yang <Philip.Yang@amd.com>
Reviewed-by: default avatarHarish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 0c673428

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

+7 −2
Original line number Diff line number Diff line
@@ -2586,12 +2586,17 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info, 
			 * from the KFD, trigger a segmentation fault in VM debug mode.

			 */

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

				struct kfd_process *p;



				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);

				p = kfd_lookup_process_by_pid(process_info->pid);

				if (p) {

					kfd_signal_vm_fault_event_with_userptr(p, mem->va);

					kfd_unref_process(p);

				}

			}



			ret = 0;