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Commit 325f04db authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
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[PATCH] pfnmap: do_no_page BUG_ON again 



Use copy_user_highpage directly instead of cow_user_page in do_no_page:
in the immediately following page_cache_release, and elsewhere, it is
assuming that new_page is normal.  If any VM_PFNMAP driver can get to
do_no_page, it's just a BUG (but not in the case of do_anonymous_page).

Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e5bbe4df

mm/memory.c

+3 −1
Original line number Diff line number Diff line
@@ -2009,6 +2009,8 @@ static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma, 
	int anon = 0;



	pte_unmap(page_table);

	BUG_ON(vma->vm_flags & VM_PFNMAP);



	if (vma->vm_file) {

		mapping = vma->vm_file->f_mapping;

		sequence = mapping->truncate_count;
@@ -2041,7 +2043,7 @@ static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma, 
		page = alloc_page_vma(GFP_HIGHUSER, vma, address);

		if (!page)

			goto oom;

		cow_user_page(page, new_page, address);

		copy_user_highpage(page, new_page, address);

		page_cache_release(new_page);

		new_page = page;

		anon = 1;