From 325f04dbca60a4cfe4ac25e7cf246edd07eb4c5f Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hugh@veritas.com>
Date: Tue, 29 Nov 2005 16:55:48 +0000
Subject: [PATCH] [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: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
mm/memory.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index ae259b6e5a211..5bfa52a986305 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -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;
--
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