special_mapping

static vm_fault_t special_mapping_fault(struct vm_fault *vmf)
{
    struct vm_area_struct *vma = vmf->vma;
    pgoff_t pgoff;
    struct page **pages;
 
    if (vma->vm_ops == &legacy_special_mapping_vmops) {
        pages = vma->vm_private_data;
    } else {
        struct vm_special_mapping *sm = vma->vm_private_data;
 
        if (sm->fault)
            return sm->fault(sm, vmf->vma, vmf);
 
        pages = sm->pages;
    }
 
    for (pgoff = vmf->pgoff; pgoff && *pages; ++pages)
        pgoff--;
 
    if (*pages) {
        struct page *page = *pages;
        get_page(page);
        vmf->page = page;
        return 0;
    }
 
    return VM_FAULT_SIGBUS;
}
函数源码
