[PATCH] Fix MPOL_F_VERIFY

There was a pretty bad bug in there that the code would always check the full VMA, not the range the user requested. When the VMA to be checked was merged with the previous VMA this could lead to spurious failures. Signed-off-by: "Andi Kleen" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
kyagi · Sep 13, 2005 · 5b952b3 · 5b952b3
1 parent 8d0986e
commit 5b952b3
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
@@ -333,8 +333,13 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 		if (prev && prev->vm_end < vma->vm_start)
 			return ERR_PTR(-EFAULT);
 		if ((flags & MPOL_MF_STRICT) && !is_vm_hugetlb_page(vma)) {
+			unsigned long endvma = vma->vm_end;
+			if (endvma > end)
+				endvma = end;
+			if (vma->vm_start > start)
+				start = vma->vm_start;
 			err = check_pgd_range(vma->vm_mm,
-					   vma->vm_start, vma->vm_end, nodes);
+					   start, endvma, nodes);
 			if (err) {
 				first = ERR_PTR(err);
 				break;