[PATCH] nommu: get_user_pages(): pin last page on non-page-aligned start

[Steven J. Magnani]

The noMMU version of get_user_pages() fails to pin the last page
when the start address isn't page-aligned. The patch fixes this in a way
that makes find_extend_vma() congruent to its MMU cousin.

Signed-off-by: Steven J. Magnani <steve@xxxxxxxxxxxxxxx>
---
diff -uprN a/mm/nommu.c b/mm/nommu.c
--- a/mm/nommu.c	2010-03-01 16:37:31.000000000 -0600
+++ b/mm/nommu.c	2010-03-01 21:34:49.000000000 -0600
@@ -146,7 +146,7 @@ int __get_user_pages(struct task_struct 
 			(VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
 
 	for (i = 0; i < nr_pages; i++) {
-		vma = find_vma(mm, start);
+		vma = find_extend_vma(mm, start);
 		if (!vma)
 			goto finish_or_fault;
 
@@ -764,7 +764,7 @@ EXPORT_SYMBOL(find_vma);
  */
 struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
 {
-	return find_vma(mm, addr);
+	return find_vma(mm, addr & PAGE_MASK);
 }
 
 /*

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/