除了手动浏览页面目录条目之外,是否有任何合适的方法可以通过逻辑地址获取物理地址?我在内核的源代码中寻找了此功能,并发现有一个follow_page功能可以很好地利用内置的巨大和透明页面支持。但是它没有导出到内核模块(为什么?)…
follow_page
因此,我不想发明轮子,我认为follow_page手动重新实现功能不是很好。
好吧,它看起来可能像这样(在虚拟地址后跟随PTE):
void follow_pte(struct mm_struct * mm, unsigned long address, pte_t * entry) { pgd_t * pgd = pgd_offset(mm, address); printk("follow_pte() for %lx\n", address); entry->pte = 0; if (!pgd_none(*pgd) && !pgd_bad(*pgd)) { pud_t * pud = pud_offset(pgd, address); struct vm_area_struct * vma = find_vma(mm, address); printk(" pgd = %lx\n", pgd_val(*pgd)); if (pud_none(*pud)) { printk(" pud = empty\n"); return; } if (pud_huge(*pud) && vma->vm_flags & VM_HUGETLB) { entry->pte = pud_val(*pud); printk(" pud = huge\n"); return; } if (!pud_bad(*pud)) { pmd_t * pmd = pmd_offset(pud, address); printk(" pud = %lx\n", pud_val(*pud)); if (pmd_none(*pmd)) { printk(" pmd = empty\n"); return; } if (pmd_huge(*pmd) && vma->vm_flags & VM_HUGETLB) { entry->pte = pmd_val(*pmd); printk(" pmd = huge\n"); return; } if (pmd_trans_huge(*pmd)) { entry->pte = pmd_val(*pmd); printk(" pmd = trans_huge\n"); return; } if (!pmd_bad(*pmd)) { pte_t * pte = pte_offset_map(pmd, address); printk(" pmd = %lx\n", pmd_val(*pmd)); if (!pte_none(*pte)) { entry->pte = pte_val(*pte); printk(" pte = %lx\n", pte_val(*pte)); } else { printk(" pte = empty\n"); } pte_unmap(pte); } } } }