Hello Sreekant Somasekharan,
This is a semi-automatic email about new static checker warnings.
Commit 628e1ace2379 ("drm/amdkfd: mark GFX12 system and peer GPU
memory mappings as MTYPE_NC") from Mar 26, 2024, leads to the
following Smatch complaint:
drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c:518 gmc_v12_0_get_vm_pte()
warn: variable dereferenced before check 'bo' (see line 500)
drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
499 struct amdgpu_bo *bo = mapping->bo_va->base.bo;
500 struct amdgpu_device *bo_adev = amdgpu_ttm_adev(bo->tbo.bdev);
^^^^
501 bool coherent = bo->flags & AMDGPU_GEM_CREATE_COHERENT;
^^^^^^^^^
502 bool is_system = bo->tbo.resource->mem_type == TTM_PL_SYSTEM;
^^^^^^^
The patch adds unchecked dereferences.
503
504
505 *flags &= ~AMDGPU_PTE_EXECUTABLE;
506 *flags |= mapping->flags & AMDGPU_PTE_EXECUTABLE;
507
508 *flags &= ~AMDGPU_PTE_MTYPE_GFX12_MASK;
509 *flags |= (mapping->flags & AMDGPU_PTE_MTYPE_GFX12_MASK);
510
511 if (mapping->flags & AMDGPU_PTE_PRT_GFX12) {
512 *flags |= AMDGPU_PTE_PRT_GFX12;
513 *flags |= AMDGPU_PTE_SNOOPED;
514 *flags |= AMDGPU_PTE_SYSTEM;
515 *flags &= ~AMDGPU_PTE_VALID;
516 }
517
518 if (bo && bo->flags & (AMDGPU_GEM_CREATE_COHERENT |
^^
But previously we assumed bo could be NULL.
519 AMDGPU_GEM_CREATE_UNCACHED))
520 *flags = (*flags & ~AMDGPU_PTE_MTYPE_GFX12_MASK) |
regards,
dan carpenter
