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Diffstat (limited to 'mm/pagewalk.c')
-rw-r--r--mm/pagewalk.c31
1 files changed, 25 insertions, 6 deletions
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 6732fc7ac4c8..5895ce4f1a85 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -4,6 +4,22 @@
#include <linux/sched.h>
#include <linux/hugetlb.h>
+/*
+ * We want to know the real level where a entry is located ignoring any
+ * folding of levels which may be happening. For example if p4d is folded then
+ * a missing entry found at level 1 (p4d) is actually at level 0 (pgd).
+ */
+static int real_depth(int depth)
+{
+ if (depth == 3 && PTRS_PER_PMD == 1)
+ depth = 2;
+ if (depth == 2 && PTRS_PER_PUD == 1)
+ depth = 1;
+ if (depth == 1 && PTRS_PER_P4D == 1)
+ depth = 0;
+ return depth;
+}
+
static int walk_pte_range_inner(pte_t *pte, unsigned long addr,
unsigned long end, struct mm_walk *walk)
{
@@ -49,6 +65,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
unsigned long next;
const struct mm_walk_ops *ops = walk->ops;
int err = 0;
+ int depth = real_depth(3);
pmd = pmd_offset(pud, addr);
do {
@@ -56,7 +73,7 @@ again:
next = pmd_addr_end(addr, end);
if (pmd_none(*pmd) || (!walk->vma && !walk->no_vma)) {
if (ops->pte_hole)
- err = ops->pte_hole(addr, next, walk);
+ err = ops->pte_hole(addr, next, depth, walk);
if (err)
break;
continue;
@@ -106,6 +123,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
unsigned long next;
const struct mm_walk_ops *ops = walk->ops;
int err = 0;
+ int depth = real_depth(2);
pud = pud_offset(p4d, addr);
do {
@@ -113,7 +131,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
next = pud_addr_end(addr, end);
if (pud_none(*pud) || (!walk->vma && !walk->no_vma)) {
if (ops->pte_hole)
- err = ops->pte_hole(addr, next, walk);
+ err = ops->pte_hole(addr, next, depth, walk);
if (err)
break;
continue;
@@ -154,13 +172,14 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
unsigned long next;
const struct mm_walk_ops *ops = walk->ops;
int err = 0;
+ int depth = real_depth(1);
p4d = p4d_offset(pgd, addr);
do {
next = p4d_addr_end(addr, end);
if (p4d_none_or_clear_bad(p4d)) {
if (ops->pte_hole)
- err = ops->pte_hole(addr, next, walk);
+ err = ops->pte_hole(addr, next, depth, walk);
if (err)
break;
continue;
@@ -192,7 +211,7 @@ static int walk_pgd_range(unsigned long addr, unsigned long end,
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd)) {
if (ops->pte_hole)
- err = ops->pte_hole(addr, next, walk);
+ err = ops->pte_hole(addr, next, 0, walk);
if (err)
break;
continue;
@@ -239,7 +258,7 @@ static int walk_hugetlb_range(unsigned long addr, unsigned long end,
if (pte)
err = ops->hugetlb_entry(pte, hmask, addr, next, walk);
else if (ops->pte_hole)
- err = ops->pte_hole(addr, next, walk);
+ err = ops->pte_hole(addr, next, -1, walk);
if (err)
break;
@@ -283,7 +302,7 @@ static int walk_page_test(unsigned long start, unsigned long end,
if (vma->vm_flags & VM_PFNMAP) {
int err = 1;
if (ops->pte_hole)
- err = ops->pte_hole(start, end, walk);
+ err = ops->pte_hole(start, end, -1, walk);
return err ? err : 1;
}
return 0;