[PATCH] unpaged: get_user_pages VM_RESERVED

The PageReserved removal in 2.6.15-rc1 prohibited get_user_pages on the areas
flagged VM_RESERVED in place of PageReserved.  That is correct in theory - we
ought not to interfere with struct pages in such a reserved area; but in
practice it broke BTTV for one.

So revert to prohibiting only on VM_IO: if someone gets into trouble with
get_user_pages on VM_RESERVED, it'll just be a "don't do that".

You can argue that videobuf_mmap_mapper shouldn't set VM_RESERVED in the first
place, but now's not the time for breaking drivers without notice.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Hugh Dickins 2005-11-21 21:32:11 -08:00 committed by Linus Torvalds
parent aa1a64ee12
commit ed5297a940

View file

@ -968,7 +968,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
continue;
}
if (!vma || (vma->vm_flags & (VM_IO | VM_RESERVED))
if (!vma || (vma->vm_flags & VM_IO)
|| !(vm_flags & vma->vm_flags))
return i ? : -EFAULT;