From ab2f7a5c18b5c17cc94aaab7ae2e7d1fa08993d6 Mon Sep 17 00:00:00 2001 From: Felix Kuehling Date: Tue, 9 Jul 2019 19:12:44 -0400 Subject: drm/amdgpu: Implement VRAM wipe on release MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Wipe VRAM memory containing sensitive data when moving or releasing BOs. Clearing the memory is pipelined to minimize any impact on subsequent memory allocation latency. Use of a poison value should help debug future use-after-free bugs. When moving BOs, the existing ttm_bo_pipelined_move ensures that the memory won't be reused before being wiped. When releasing BOs, the BO is fenced with the memory fill operation, which results in queuing the BO for a delayed delete. v2: Move amdgpu_amdkfd_unreserve_memory_limit into amdgpu_bo_release_notify so that KFD can use memory that's still being cleared in the background Signed-off-by: Felix Kuehling Reviewed-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 39 +++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_object.c') diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c index 531251dff150..0c0a8e83ab83 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c @@ -80,9 +80,6 @@ static void amdgpu_bo_destroy(struct ttm_buffer_object *tbo) if (bo->pin_count > 0) amdgpu_bo_subtract_pin_size(bo); - if (bo->kfd_bo) - amdgpu_amdkfd_unreserve_memory_limit(bo); - amdgpu_bo_kunmap(bo); if (bo->gem_base.import_attach) @@ -1220,6 +1217,42 @@ void amdgpu_bo_move_notify(struct ttm_buffer_object *bo, trace_amdgpu_bo_move(abo, new_mem->mem_type, old_mem->mem_type); } +/** + * amdgpu_bo_move_notify - notification about a BO being released + * @bo: pointer to a buffer object + * + * Wipes VRAM buffers whose contents should not be leaked before the + * memory is released. + */ +void amdgpu_bo_release_notify(struct ttm_buffer_object *bo) +{ + struct dma_fence *fence = NULL; + struct amdgpu_bo *abo; + int r; + + if (!amdgpu_bo_is_amdgpu_bo(bo)) + return; + + abo = ttm_to_amdgpu_bo(bo); + + if (abo->kfd_bo) + amdgpu_amdkfd_unreserve_memory_limit(abo); + + if (bo->mem.mem_type != TTM_PL_VRAM || !bo->mem.mm_node || + !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE)) + return; + + reservation_object_lock(bo->resv, NULL); + + r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->resv, &fence); + if (!WARN_ON(r)) { + amdgpu_bo_fence(abo, fence, false); + dma_fence_put(fence); + } + + reservation_object_unlock(bo->resv); +} + /** * amdgpu_bo_fault_reserve_notify - notification about a memory fault * @bo: pointer to a buffer object -- cgit v1.2.3