arm64中内核虚拟地址的内存属性

Question

我试图在内核模块中读取通过kmalloc分配的虚拟内存地址的内存属性。

使用arch / arm64 / include / asm / pgtable.h中提供的api进行手动页面表行走。

以下是代码。

{
    unsigned int attr;
    pud_t *pud;
    pmd_t *pmd;
    pte_t *pte; 
    pgd_t *pgd, *swapper_pgd;
    struct page *pg = phys_to_page(read_sysreg(ttbr1_el1));

    swapper_pgd = (pgd_t*) kmap(pg);
    pgd = pgd_offset_raw(swapper_pgd, (uint64_t)buf);
    pgd_ptr = (pgd_t *)kmap(pgd_page(*pgd));
    if(!pgd)
       return 0;
    kunmap(pg);
    pg = phys_to_page(pud_offset_phys(pgd, (uint64_t)buf));
    pud = (pud_t *)kmap(pg);
    if(!pud)
      return 0;
    kunmap(pg);
    pg = phys_to_page(pmd_offset_phys(pud, (uint64_t)buf));
    pmd = (pmd_t *)kmap(pg);
    if(!pmd)
       return 0;
    kunmap(pg);
    pg = phys_to_page(pte_offset_phys(pmd, (uint64_t)buf));
    pte = (pte_t *)kmap(pg);
    if(!pte)
       return 0;
    attr = PTE_ATTRINDX_MASK & pte_val(*pte);
    kunmap(pg);
    return attr;
} 

我可以依赖从此代码中获取的内存属性值吗？