aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--fs/proc/task_mmu.c4
-rw-r--r--include/linux/pagewalk.h7
-rw-r--r--mm/hmm.c8
-rw-r--r--mm/migrate.c5
-rw-r--r--mm/mincore.c1
-rw-r--r--mm/pagewalk.c31
6 files changed, 40 insertions, 16 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 9442631fd4af..3ba9ae83bff5 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -505,7 +505,7 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
#ifdef CONFIG_SHMEM
static int smaps_pte_hole(unsigned long addr, unsigned long end,
- struct mm_walk *walk)
+ __always_unused int depth, struct mm_walk *walk)
{
struct mem_size_stats *mss = walk->private;
@@ -1282,7 +1282,7 @@ static int add_to_pagemap(unsigned long addr, pagemap_entry_t *pme,
}
static int pagemap_pte_hole(unsigned long start, unsigned long end,
- struct mm_walk *walk)
+ __always_unused int depth, struct mm_walk *walk)
{
struct pagemapread *pm = walk->private;
unsigned long addr = start;
diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h
index d5d07f7a9c14..745a654c6ea7 100644
--- a/include/linux/pagewalk.h
+++ b/include/linux/pagewalk.h
@@ -17,7 +17,10 @@ struct mm_walk;
* split_huge_page() instead of handling it explicitly.
* @pte_entry: if set, called for each non-empty PTE (lowest-level)
* entry
- * @pte_hole: if set, called for each hole at all levels
+ * @pte_hole: if set, called for each hole at all levels,
+ * depth is -1 if not known, 0:PGD, 1:P4D, 2:PUD, 3:PMD
+ * 4:PTE. Any folded depths (where PTRS_PER_P?D is equal
+ * to 1) are skipped.
* @hugetlb_entry: if set, called for each hugetlb entry
* @test_walk: caller specific callback function to determine whether
* we walk over the current vma or not. Returning 0 means
@@ -43,7 +46,7 @@ struct mm_walk_ops {
int (*pte_entry)(pte_t *pte, unsigned long addr,
unsigned long next, struct mm_walk *walk);
int (*pte_hole)(unsigned long addr, unsigned long next,
- struct mm_walk *walk);
+ int depth, struct mm_walk *walk);
int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
unsigned long addr, unsigned long next,
struct mm_walk *walk);
diff --git a/mm/hmm.c b/mm/hmm.c
index c49e9dfce5b4..72e5a6d9a417 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -186,7 +186,7 @@ static void hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk,
}
static int hmm_vma_walk_hole(unsigned long addr, unsigned long end,
- struct mm_walk *walk)
+ __always_unused int depth, struct mm_walk *walk)
{
struct hmm_vma_walk *hmm_vma_walk = walk->private;
struct hmm_range *range = hmm_vma_walk->range;
@@ -380,7 +380,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
again:
pmd = READ_ONCE(*pmdp);
if (pmd_none(pmd))
- return hmm_vma_walk_hole(start, end, walk);
+ return hmm_vma_walk_hole(start, end, -1, walk);
if (thp_migration_supported() && is_pmd_migration_entry(pmd)) {
bool fault, write_fault;
@@ -487,7 +487,7 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
pud = READ_ONCE(*pudp);
if (pud_none(pud)) {
- ret = hmm_vma_walk_hole(start, end, walk);
+ ret = hmm_vma_walk_hole(start, end, -1, walk);
goto out_unlock;
}
@@ -497,7 +497,7 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
bool fault, write_fault;
if (!pud_present(pud)) {
- ret = hmm_vma_walk_hole(start, end, walk);
+ ret = hmm_vma_walk_hole(start, end, -1, walk);
goto out_unlock;
}
diff --git a/mm/migrate.c b/mm/migrate.c
index edf42ed90030..b1092876e537 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2151,6 +2151,7 @@ out_unlock:
#ifdef CONFIG_DEVICE_PRIVATE
static int migrate_vma_collect_hole(unsigned long start,
unsigned long end,
+ __always_unused int depth,
struct mm_walk *walk)
{
struct migrate_vma *migrate = walk->private;
@@ -2195,7 +2196,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
again:
if (pmd_none(*pmdp))
- return migrate_vma_collect_hole(start, end, walk);
+ return migrate_vma_collect_hole(start, end, -1, walk);
if (pmd_trans_huge(*pmdp)) {
struct page *page;
@@ -2228,7 +2229,7 @@ again:
return migrate_vma_collect_skip(start, end,
walk);
if (pmd_none(*pmdp))
- return migrate_vma_collect_hole(start, end,
+ return migrate_vma_collect_hole(start, end, -1,
walk);
}
}
diff --git a/mm/mincore.c b/mm/mincore.c
index 49b6fa2f6aa1..0e6dd9948f1a 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -112,6 +112,7 @@ static int __mincore_unmapped_range(unsigned long addr, unsigned long end,
}
static int mincore_unmapped_range(unsigned long addr, unsigned long end,
+ __always_unused int depth,
struct mm_walk *walk)
{
walk->private += __mincore_unmapped_range(addr, end,
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;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.