From b65709a92156b850840edba9f9932e10c235d44e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Christian=20K=C3=B6nig?= Date: Wed, 17 Jul 2019 09:58:47 +0200 Subject: [PATCH] drm/amdgpu: reserve the root PD while freeing PASIDs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Free the pasid only while the root PD is reserved. This prevents use after free in the page fault handling. Signed-off-by: Christian König Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c index 5dc1e0b319fb..696253ebdf98 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c @@ -2945,18 +2945,26 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm) struct amdgpu_bo_va_mapping *mapping, *tmp; bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt; struct amdgpu_bo *root; - int i, r; + int i; amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm); + root = amdgpu_bo_ref(vm->root.base.bo); + amdgpu_bo_reserve(root, true); if (vm->pasid) { unsigned long flags; spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags); idr_remove(&adev->vm_manager.pasid_idr, vm->pasid); spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags); + vm->pasid = 0; } + amdgpu_vm_free_pts(adev, vm, NULL); + amdgpu_bo_unreserve(root); + amdgpu_bo_unref(&root); + WARN_ON(vm->root.base.bo); + drm_sched_entity_destroy(&vm->direct); drm_sched_entity_destroy(&vm->delayed); @@ -2981,16 +2989,6 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm) amdgpu_vm_free_mapping(adev, vm, mapping, NULL); } - root = amdgpu_bo_ref(vm->root.base.bo); - r = amdgpu_bo_reserve(root, true); - if (r) { - dev_err(adev->dev, "Leaking page tables because BO reservation failed\n"); - } else { - amdgpu_vm_free_pts(adev, vm, NULL); - amdgpu_bo_unreserve(root); - } - amdgpu_bo_unref(&root); - WARN_ON(vm->root.base.bo); dma_fence_put(vm->last_update); for (i = 0; i < AMDGPU_MAX_VMHUBS; i++) amdgpu_vmid_free_reserved(adev, vm, i); -- 2.30.2