linux-2.6.33/__get_user_pages()(nommu) の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-2.6.33/__get_user_pages()(nommu) へ行く。
  • 1 (2013-03-03 (日) 05:04:59)

参照元†

• linux-2.6.33/__get_user_pages()

説明†

• パス: linux-2.6.33/mm/nommu.c

• FIXME: これは何？
  • 説明

引数†

• struct task_struct *tsk
  • linux-2.6.33/task_struct
• struct mm_struct *mm
  • linux-2.6.33/mm_struct
• unsigned long start
• int nr_pages
• int write
• int force
• struct page **pages
  • linux-2.6.33/page
• struct vm_area_struct **vmas
  • linux-2.6.33/vm_area_struct

返り値†

• int

参考†

実装†

int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
		     unsigned long start, int nr_pages, unsigned int foll_flags,
		     struct page **pages, struct vm_area_struct **vmas)
{
	struct vm_area_struct *vma;
	unsigned long vm_flags;
	int i;

	/* calculate required read or write permissions.
	 * If FOLL_FORCE is set, we only require the "MAY" flags.
	 */
	vm_flags  = (foll_flags & FOLL_WRITE) ?
			(VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
	vm_flags &= (foll_flags & FOLL_FORCE) ?
			(VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);

• • linux-2.6.33/FOLL_WRITE

• linux-2.6.33/FOLL_FORCE

• • linux-2.6.33/VM_WRITE

• linux-2.6.33/VM_MAYWRITE

• • linux-2.6.33/VM_READ

• linux-2.6.33/VM_MAYREAD

	for (i = 0; i < nr_pages; i++) {
		vma = find_vma(mm, start);
		if (!vma)
			goto finish_or_fault;

• • linux-2.6.33/find_vma()

		/* protect what we can, including chardevs */
		if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
		    !(vm_flags & vma->vm_flags))
			goto finish_or_fault;

• • linux-2.6.33/VM_IO

• linux-2.6.33/VM_PFNMAP

		if (pages) {
			pages[i] = virt_to_page(start);
			if (pages[i])
				page_cache_get(pages[i]);
		}

• • linux-2.6.33/virt_to_page()

• linux-2.6.33/page_cache_get()

		if (vmas)
			vmas[i] = vma;
		start += PAGE_SIZE;
	}

	return i;

finish_or_fault:
	return i ? : -EFAULT;
}

コメント†