[PATCH v3 35/48] mm: Pass vma iterator through to __vma_adjust()

Liam Howlett
2023-01-17T02:39:17Z

Pass the iterator through to be used in __vma_adjust(). The state of
the iterator needs to be correct for the operation that will occur so
make the adjustments.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
mm/mmap.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index b37206f89e59..a8908280671f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -528,6 +528,10 @@ inline int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
vma_interval_tree_remove(vma, root);
}

+ /* VMA iterator points to previous, so set to start if necessary */
+ if (vma_iter_addr(vmi) != start)
+ vma_iter_set(vmi, start);
+
vma->vm_start = start;
vma->vm_end = end;
vma->vm_pgoff = pgoff;
@@ -2163,13 +2167,13 @@ static void unmap_region(struct mm_struct *mm, struct maple_tree *mt,
/*
* __split_vma() bypasses sysctl_max_map_count checking. We use this where it
* has already been checked or doesn't make sense to fail.
+ * VMA Iterator will point to the end VMA.
*/
int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long addr, int new_below)
{
struct vm_area_struct *new;
int err;
- unsigned long end = vma->vm_end;

validate_mm_mt(vma->vm_mm);

@@ -2205,14 +2209,17 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
new->vm_ops->open(new);

if (new_below)
- err = vma_adjust(vma, addr, vma->vm_end, vma->vm_pgoff +
- ((addr - new->vm_start) >> PAGE_SHIFT), new);
+ err = __vma_adjust(vmi, vma, addr, vma->vm_end,
+ vma->vm_pgoff + ((addr - new->vm_start) >> PAGE_SHIFT),
+ new, NULL);
else
- err = vma_adjust(vma, vma->vm_start, addr, vma->vm_pgoff, new);
+ err = __vma_adjust(vmi, vma, vma->vm_start, addr, vma->vm_pgoff,
+ new, NULL);

/* Success. */
if (!err) {
- vma_iter_set(vmi, end);
+ if (new_below)
+ vma_next(vmi);
return 0;
}

@@ -2307,8 +2314,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
if (error)
goto start_split_failed;

- vma_iter_set(vmi, start);
- vma = vma_find(vmi, end);
+ vma = vma_iter_load(vmi);
}

prev = vma_prev(vmi);
@@ -2328,7 +2334,6 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
if (error)
goto end_split_failed;

- vma_iter_set(vmi, end);
split = vma_prev(vmi);
error = munmap_sidetree(split, &mas_detach);
if (error)
@@ -2572,6 +2577,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
goto unacct_error;
}

+ vma_iter_set(&vmi, addr);
vma->vm_start = addr;
vma->vm_end = end;
vma->vm_flags = vm_flags;
--
2.35.1