drm/amdgpu: Cast to uint64_t before left shift

Avoid potential integer overflows with left shift in huge-page mapping
code by casting the operand to uin64_t first.

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

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index dad0e23..be3e360 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -181,7 +181,7 @@ static unsigned amdgpu_vm_num_entries(struct amdgpu_device *adev,
 
        if (level == adev->vm_manager.root_level)
                /* For the root directory */
-               return round_up(adev->vm_manager.max_pfn, 1 << shift) >> shift;
+               return round_up(adev->vm_manager.max_pfn, 1ULL << shift) >> shift;
        else if (level != AMDGPU_VM_PTB)
                /* Everything in between */
                return 512;
@@ -1666,10 +1666,10 @@ static int amdgpu_vm_update_ptes(struct amdgpu_pte_update_params *params,
                }
 
                /* Looks good so far, calculate parameters for the update */
-               incr = AMDGPU_GPU_PAGE_SIZE << shift;
+               incr = (uint64_t)AMDGPU_GPU_PAGE_SIZE << shift;
                mask = amdgpu_vm_entries_mask(adev, cursor.level);
                pe_start = ((cursor.pfn >> shift) & mask) * 8;
-               entry_end = (mask + 1) << shift;
+               entry_end = (uint64_t)(mask + 1) << shift;
                entry_end += cursor.pfn & ~(entry_end - 1);
                entry_end = min(entry_end, end);
 
@@ -1682,7 +1682,7 @@ static int amdgpu_vm_update_ptes(struct amdgpu_pte_update_params *params,
                                              flags | AMDGPU_PTE_FRAG(frag));
 
                        pe_start += nptes * 8;
-                       dst += nptes * AMDGPU_GPU_PAGE_SIZE << shift;
+                       dst += (uint64_t)nptes * AMDGPU_GPU_PAGE_SIZE << shift;
 
                        frag_start = upd_end;
                        if (frag_start >= frag_end) {