[PATCH] unpaged: ZERO_PAGE in VM_UNPAGED

It's strange enough to be looking out for anonymous pages in VM_UNPAGED areas,
let's not insert the ZERO_PAGE there - though whether it would matter will
depend on what we decide about ZERO_PAGE refcounting.

But whereas do_anonymous_page may (exceptionally) be called on a VM_UNPAGED
area, do_no_page should never be: just BUG_ON.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 91dd669273e0..29c3b631445a 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -591,7 +591,7 @@ static inline size_t read_zero_pagealigned(char __user * buf, size_t size)
 
                 if (vma->vm_start > addr || (vma->vm_flags & VM_WRITE) == 0)
                         goto out_up;
-                if (vma->vm_flags & (VM_SHARED | VM_HUGETLB))
+                if (vma->vm_flags & (VM_SHARED | VM_HUGETLB | VM_UNPAGED))
                         break;
                 count = vma->vm_end - addr;
                 if (count > size)