Linux 下获取某虚拟地址对应的页表信息

即给出某个虚拟地址，通过查询页表信息，将其转换成物理地址。

 

//该函数用于查询address对应的页表。摘自arch/x86/mm/fault.c

static void dump_pagetable(unsigned long address)

{

       pgd_t *base = __va(read_cr3() & PHYSICAL_PAGE_MASK); //页目录表基址

       pgd_t *pgd = base + pgd_index(address);

       pud_t *pud;           // 页表级数大于 3

       pmd_t *pmd;         // 页表级数大于 2

       pte_t *pte;

 

       if (bad_address(pgd))

              goto bad;

 

       printk("PGD %lx ", pgd_val(*pgd));

 

       if (!pgd_present(*pgd))

              goto out;

 

       pud = pud_offset(pgd, address);

       if (bad_address(pud))

              goto bad;

 

       printk("PUD %lx ", pud_val(*pud));

       if (!pud_present(*pud) || pud_large(*pud))

              goto out;

 

       pmd = pmd_offset(pud, address);

       if (bad_address(pmd))

              goto bad;

 

       printk("PMD %lx ", pmd_val(*pmd));

       if (!pmd_present(*pmd) || pmd_large(*pmd))

              goto out;

 

       pte = pte_offset_kernel(pmd, address);

       if (bad_address(pte))

              goto bad;

 

       printk("PTE %lx", pte_val(*pte));

out:

       printk("/n");

       return;

bad:

       printk("BAD/n");

}

 之后转换成物理地址： pa = (pte_val(*pte) & PAGE_MASK | (address & ~PAGE_MASK);