The patch titled
Subject: mm/mlock: use vma iterator and maple state instead of vma linked list
has been added to the -mm mm-unstable branch. Its filename is
mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm/mlock: use vma iterator and maple state instead of vma linked list
Date: Mon, 22 Aug 2022 15:06:30 +0000
Handle overflow checking in count_mm_mlocked_page_nr() differently.
Link: https://lkml.kernel.org/r/20220822150128.1562046-58-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mlock.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
--- a/mm/mlock.c~mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list
+++ a/mm/mlock.c
@@ -471,6 +471,7 @@ static int apply_vma_lock_flags(unsigned
unsigned long nstart, end, tmp;
struct vm_area_struct *vma, *prev;
int error;
+ MA_STATE(mas, ¤t->mm->mm_mt, start, start);
VM_BUG_ON(offset_in_page(start));
VM_BUG_ON(len != PAGE_ALIGN(len));
@@ -479,13 +480,14 @@ static int apply_vma_lock_flags(unsigned
return -EINVAL;
if (end == start)
return 0;
- vma = find_vma(current->mm, start);
- if (!vma || vma->vm_start > start)
+ vma = mas_walk(&mas);
+ if (!vma)
return -ENOMEM;
- prev = vma->vm_prev;
if (start > vma->vm_start)
prev = vma;
+ else
+ prev = mas_prev(&mas, 0);
for (nstart = start ; ; ) {
vm_flags_t newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
@@ -505,7 +507,7 @@ static int apply_vma_lock_flags(unsigned
if (nstart >= end)
break;
- vma = prev->vm_next;
+ vma = find_vma(prev->vm_mm, prev->vm_end);
if (!vma || vma->vm_start != nstart) {
error = -ENOMEM;
break;
@@ -526,24 +528,23 @@ static unsigned long count_mm_mlocked_pa
{
struct vm_area_struct *vma;
unsigned long count = 0;
+ unsigned long end;
+ VMA_ITERATOR(vmi, mm, start);
if (mm == NULL)
mm = current->mm;
- vma = find_vma(mm, start);
- if (vma == NULL)
- return 0;
-
- for (; vma ; vma = vma->vm_next) {
- if (start >= vma->vm_end)
- continue;
- if (start + len <= vma->vm_start)
- break;
+ /* Don't overflow past ULONG_MAX */
+ if (unlikely(ULONG_MAX - len < start))
+ end = ULONG_MAX;
+ else
+ end = start + len;
+ for_each_vma_range(vmi, vma, end) {
if (vma->vm_flags & VM_LOCKED) {
if (start > vma->vm_start)
count -= (start - vma->vm_start);
- if (start + len < vma->vm_end) {
- count += start + len - vma->vm_start;
+ if (end < vma->vm_end) {
+ count += end - vma->vm_start;
break;
}
count += vma->vm_end - vma->vm_start;
@@ -659,6 +660,7 @@ SYSCALL_DEFINE2(munlock, unsigned long,
*/
static int apply_mlockall_flags(int flags)
{
+ MA_STATE(mas, ¤t->mm->mm_mt, 0, 0);
struct vm_area_struct *vma, *prev = NULL;
vm_flags_t to_add = 0;
@@ -679,7 +681,7 @@ static int apply_mlockall_flags(int flag
to_add |= VM_LOCKONFAULT;
}
- for (vma = current->mm->mmap; vma ; vma = prev->vm_next) {
+ mas_for_each(&mas, vma, ULONG_MAX) {
vm_flags_t newflags;
newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
@@ -687,6 +689,7 @@ static int apply_mlockall_flags(int flag
/* Ignore errors */
mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags);
+ mas_pause(&mas);
cond_resched();
}
out:
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
support-highmem-pages-in-vmap_pages_range_noflush.patch
mm-add-vma-iterator.patch
mmap-use-the-vma-iterator-in-count_vma_pages_range.patch
proc-remove-vma-rbtree-use-from-nommu.patch
arm64-remove-mmap-linked-list-from-vdso.patch
parisc-remove-mmap-linked-list-from-cache-handling.patch
powerpc-remove-mmap-linked-list-walks.patch
s390-remove-vma-linked-list-walks.patch
x86-remove-vma-linked-list-walks.patch
xtensa-remove-vma-linked-list-walks.patch
cxl-remove-vma-linked-list-walk.patch
optee-remove-vma-linked-list-walk.patch
um-remove-vma-linked-list-walk.patch
coredump-remove-vma-linked-list-walk.patch
exec-use-vma-iterator-instead-of-linked-list.patch
fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end.patch
acct-use-vma-iterator-instead-of-linked-list.patch
perf-use-vma-iterator.patch
sched-use-maple-tree-iterator-to-walk-vmas.patch
fork-use-vma-iterator.patch
mm-khugepaged-stop-using-vma-linked-list.patch
mm-ksm-use-vma-iterators-instead-of-vma-linked-list.patch
mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch
mm-pagewalk-use-vma_find-instead-of-vma-linked-list.patch
i915-use-the-vma-iterator.patch
nommu-remove-uses-of-vma-linked-list.patch
