From: Hugh Dickins <hugh@veritas.com>
The follow_page write-access case is relying on pte_page before checking
pfn_valid: rearrange that - and we don't need three struct page *pages.
(I notice mempolicy.c's verify_pages is also relying on pte_page, but I'll
leave that to Andi: maybe it ought to be failing on, or skipping over, VM_IO
or VM_RESERVED vmas?)
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/mm/memory.c | 10 +++-------
1 files changed, 3 insertions(+), 7 deletions(-)
diff -puN mm/memory.c~mm-follow_page-invalid-pte_page mm/memory.c
--- 25/mm/memory.c~mm-follow_page-invalid-pte_page Wed Jun 2 15:12:23 2004
+++ 25-akpm/mm/memory.c Wed Jun 2 15:12:23 2004
@@ -637,15 +637,11 @@ follow_page(struct mm_struct *mm, unsign
if (pte_present(pte)) {
if (write && !pte_write(pte))
goto out;
- if (write && !pte_dirty(pte)) {
- struct page *page = pte_page(pte);
- if (!PageDirty(page))
- set_page_dirty(page);
- }
pfn = pte_pfn(pte);
if (pfn_valid(pfn)) {
- struct page *page = pfn_to_page(pfn);
-
+ page = pfn_to_page(pfn);
+ if (write && !pte_dirty(pte) && !PageDirty(page))
+ set_page_dirty(page);
mark_page_accessed(page);
return page;
}
_