mlock: convert mlock to vma iterator

Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.

Link: https://lkml.kernel.org/r/20230120162650.984577-19-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Liam R. Howlett 2023-01-20 11:26:19 -05:00 committed by Andrew Morton
parent 2286a6914c
commit 37598f5a9d

View File

@ -401,8 +401,9 @@ static void mlock_vma_pages_range(struct vm_area_struct *vma,
*
* For vmas that pass the filters, merge/split as appropriate.
*/
static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
unsigned long start, unsigned long end, vm_flags_t newflags)
static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct vm_area_struct **prev, unsigned long start,
unsigned long end, vm_flags_t newflags)
{
struct mm_struct *mm = vma->vm_mm;
pgoff_t pgoff;
@ -417,22 +418,22 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
goto out;
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vma_merge(mm, *prev, start, end, newflags, vma->anon_vma,
vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
*prev = vmi_vma_merge(vmi, mm, *prev, start, end, newflags,
vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
if (*prev) {
vma = *prev;
goto success;
}
if (start != vma->vm_start) {
ret = split_vma(mm, vma, start, 1);
ret = vmi_split_vma(vmi, mm, vma, start, 1);
if (ret)
goto out;
}
if (end != vma->vm_end) {
ret = split_vma(mm, vma, end, 0);
ret = vmi_split_vma(vmi, mm, vma, end, 0);
if (ret)
goto out;
}
@ -471,7 +472,7 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
unsigned long nstart, end, tmp;
struct vm_area_struct *vma, *prev;
int error;
MA_STATE(mas, &current->mm->mm_mt, start, start);
VMA_ITERATOR(vmi, current->mm, start);
VM_BUG_ON(offset_in_page(start));
VM_BUG_ON(len != PAGE_ALIGN(len));
@ -480,39 +481,37 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
return -EINVAL;
if (end == start)
return 0;
vma = mas_walk(&mas);
vma = vma_iter_load(&vmi);
if (!vma)
return -ENOMEM;
prev = vma_prev(&vmi);
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;
nstart = start;
tmp = vma->vm_start;
for_each_vma_range(vmi, vma, end) {
vm_flags_t newflags;
if (vma->vm_start != tmp)
return -ENOMEM;
newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
newflags |= flags;
/* Here we know that vma->vm_start <= nstart < vma->vm_end. */
tmp = vma->vm_end;
if (tmp > end)
tmp = end;
error = mlock_fixup(vma, &prev, nstart, tmp, newflags);
error = mlock_fixup(&vmi, vma, &prev, nstart, tmp, newflags);
if (error)
break;
nstart = tmp;
if (nstart < prev->vm_end)
nstart = prev->vm_end;
if (nstart >= end)
break;
vma = find_vma(prev->vm_mm, prev->vm_end);
if (!vma || vma->vm_start != nstart) {
error = -ENOMEM;
break;
}
}
if (vma_iter_end(&vmi) < end)
return -ENOMEM;
return error;
}
@ -658,7 +657,7 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len)
*/
static int apply_mlockall_flags(int flags)
{
MA_STATE(mas, &current->mm->mm_mt, 0, 0);
VMA_ITERATOR(vmi, current->mm, 0);
struct vm_area_struct *vma, *prev = NULL;
vm_flags_t to_add = 0;
@ -679,15 +678,15 @@ static int apply_mlockall_flags(int flags)
to_add |= VM_LOCKONFAULT;
}
mas_for_each(&mas, vma, ULONG_MAX) {
for_each_vma(vmi, vma) {
vm_flags_t newflags;
newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
newflags |= to_add;
/* Ignore errors */
mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags);
mas_pause(&mas);
mlock_fixup(&vmi, vma, &prev, vma->vm_start, vma->vm_end,
newflags);
cond_resched();
}
out: