[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>
diff --git a/mm/memory.c b/mm/memory.c
index ae259b6..5bfa52a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2009,6 +2009,8 @@
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 @@
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;