From f7646585a30ed8ef5ab300d4dc3b0c1d6afbe71d Mon Sep 17 00:00:00 2001 From: Philip Yang Date: Thu, 21 May 2020 09:56:58 -0400 Subject: [PATCH] drm/amdkfd: fix restore worker race condition In free memory of gpu path, remove bo from validate_list to make sure restore worker don't access the BO any more, then unregister bo MMU interval notifier. Otherwise, the restore worker will crash in the middle of validating BO user pages if MMU interval notifer is gone. Signed-off-by: Philip Yang Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index da8b31a53291..68e6e1bc8f3a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -1302,15 +1302,15 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu( return -EBUSY; } - /* No more MMU notifiers */ - amdgpu_mn_unregister(mem->bo); - /* Make sure restore workers don't access the BO any more */ bo_list_entry = &mem->validate_list; mutex_lock(&process_info->lock); list_del(&bo_list_entry->head); mutex_unlock(&process_info->lock); + /* No more MMU notifiers */ + amdgpu_mn_unregister(mem->bo); + ret = reserve_bo_and_cond_vms(mem, NULL, BO_VM_ALL, &ctx); if (unlikely(ret)) return ret;