diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 047c3cd2cefff6ee326fc55dc7e937bf0e50942f..2170d975cc7670b44fb276a779a88fd16340c2d1 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -43,7 +43,8 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) struct vm_area_struct *vma = vmf->vma; struct udmabuf *ubuf = vma->vm_private_data; pgoff_t pgoff = vmf->pgoff; - unsigned long pfn; + unsigned long addr, pfn; + vm_fault_t ret; if (pgoff >= ubuf->pagecount) return VM_FAULT_SIGBUS; @@ -51,7 +52,35 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf) pfn = folio_pfn(ubuf->folios[pgoff]); pfn += ubuf->offsets[pgoff] >> PAGE_SHIFT; - return vmf_insert_pfn(vma, vmf->address, pfn); + ret = vmf_insert_pfn(vma, vmf->address, pfn); + if (ret & VM_FAULT_ERROR) + return ret; + + /* pre fault */ + pgoff = vma->vm_pgoff; + addr = vma->vm_start; + + for (; addr < vma->vm_end; pgoff++, addr += PAGE_SIZE) { + if (addr == vmf->address) + continue; + + if (WARN_ON(pgoff >= ubuf->pagecount)) + break; + + pfn = folio_pfn(ubuf->folios[pgoff]); + pfn += ubuf->offsets[pgoff] >> PAGE_SHIFT; + + /** + * If the below vmf_insert_pfn() fails, we do not return an + * error here during this pre-fault step. However, an error + * will be returned if the failure occurs when the addr is + * truly accessed. + */ + if (vmf_insert_pfn(vma, addr, pfn) & VM_FAULT_ERROR) + break; + } + + return ret; } static const struct vm_operations_struct udmabuf_vm_ops = {