drm/amdgpu: Fix potential integer overflows

With mm_nodes larger than 4GB, byte_count in amdgpu_fill_buffer would
overflow.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 333cfbdf6dd09e48f9e867650acc19565fba88c0..8462934d23eabf7ac486c1240e9d4da5117a9d37 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2059,9 +2059,9 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
        mm_node = bo->tbo.mem.mm_node;
        num_loops = 0;
        while (num_pages) {
-               uint32_t byte_count = mm_node->size << PAGE_SHIFT;
+               uint64_t byte_count = mm_node->size << PAGE_SHIFT;
 
-               num_loops += DIV_ROUND_UP(byte_count, max_bytes);
+               num_loops += DIV_ROUND_UP_ULL(byte_count, max_bytes);
                num_pages -= mm_node->size;
                ++mm_node;
        }
@@ -2087,12 +2087,13 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
        mm_node = bo->tbo.mem.mm_node;
 
        while (num_pages) {
-               uint32_t byte_count = mm_node->size << PAGE_SHIFT;
+               uint64_t byte_count = mm_node->size << PAGE_SHIFT;
                uint64_t dst_addr;
 
                dst_addr = amdgpu_mm_node_addr(&bo->tbo, mm_node, &bo->tbo.mem);
                while (byte_count) {
-                       uint32_t cur_size_in_bytes = min(byte_count, max_bytes);
+                       uint32_t cur_size_in_bytes = min_t(uint64_t, byte_count,
+                                                          max_bytes);
 
                        amdgpu_emit_fill_buffer(adev, &job->ibs[0], src_data,
                                                dst_addr, cur_size_in_bytes);