Hello Thomas Hellstrom,
The patch fb80edb0d766: "drm/vmwgfx: Implement an infrastructure for
read-coherent resources" from Mar 28, 2019, leads to the following
static checker warning:
drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c:461 vmw_bo_vm_fault()
warn: missing conversion: 'page_offset + ((1) << 12)' 'page + byte'
drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c:534 vmw_bo_vm_huge_fault()
warn: missing conversion: 'page_offset + ((1) << 12)' 'page + byte'
drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c
435 vm_fault_t vmw_bo_vm_fault(struct vm_fault *vmf)
436 {
437 struct vm_area_struct *vma = vmf->vma;
438 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
439 vma->vm_private_data;
440 struct vmw_buffer_object *vbo =
441 container_of(bo, struct vmw_buffer_object, base);
442 pgoff_t num_prefault;
443 pgprot_t prot;
444 vm_fault_t ret;
445
446 ret = ttm_bo_vm_reserve(bo, vmf);
447 if (ret)
448 return ret;
449
450 num_prefault = (vma->vm_flags & VM_RAND_READ) ? 1 :
451 TTM_BO_VM_NUM_PREFAULT;
452
453 if (vbo->dirty) {
454 pgoff_t allowed_prefault;
455 unsigned long page_offset;
456
457 page_offset = vmf->pgoff -
458 drm_vma_node_start(&bo->base.vma_node);
459 if (page_offset >= bo->resource->num_pages ||
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
page_offset is in terms of pages
460 vmw_resources_clean(vbo, page_offset,
--> 461 page_offset + PAGE_SIZE,
^^^^^^^^^^^^^^^^^^^^^^^
It doesn't make sense to add PAGE_SIZE (which is bytes) to pages. The
code in vmw_bo_vm_huge_fault() has a similar bug.
462 &allowed_prefault)) {
463 ret = VM_FAULT_SIGBUS;
464 goto out_unlock;
465 }
466
467 num_prefault = min(num_prefault, allowed_prefault);
468 }
469
470 /*
471 * If we don't track dirty using the MKWRITE method, make sure
472 * sure the page protection is write-enabled so we don't get
473 * a lot of unnecessary write faults.
474 */
475 if (vbo->dirty && vbo->dirty->method == VMW_BO_DIRTY_MKWRITE)
476 prot = vm_get_page_prot(vma->vm_flags & ~VM_SHARED);
477 else
478 prot = vm_get_page_prot(vma->vm_flags);
479
480 ret = ttm_bo_vm_fault_reserved(vmf, prot, num_prefault, 1);
481 if (ret == VM_FAULT_RETRY && !(vmf->flags &
FAULT_FLAG_RETRY_NOWAIT))
482 return ret;
483
484 out_unlock:
485 dma_resv_unlock(bo->base.resv);
486
487 return ret;
488 }
regards,
dan carpenter
