From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Fri, 18 Jun 2021 19:06:12 +0000 (-0400)
Subject: mm/mmap: Drop range_has_overlap() function
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=cc77b5d29cf01a20320f64da2fd51f96727e9e6e;p=users%2Fjedix%2Flinux-maple.git

mm/mmap: Drop range_has_overlap() function

Since there is no longer a linked list, the range_has_overlap() function
is identical to the find_vma_intersection() function.  There is only one
place that actually needs the previous vma, so just use vma_prev() in
that one case.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index 51150c2cd4c9..0e287c163bd1 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -433,30 +433,6 @@ anon_vma_interval_tree_post_update_vma(struct vm_area_struct *vma)
 		anon_vma_interval_tree_insert(avc, &avc->anon_vma->rb_root);
 }
 
-/*
- * range_has_overlap() - Check the @start - @end range for overlapping VMAs and
- * sets up a pointer to the previous VMA
- * @mm: the mm struct
- * @start: the start address of the range
- * @end: the end address of the range
- * @pprev: the pointer to the pointer of the previous VMA
- *
- * Returns: True if there is an overlapping VMA, false otherwise
- */
-static inline
-bool range_has_overlap(struct mm_struct *mm, unsigned long start,
-		       unsigned long end, struct vm_area_struct **pprev)
-{
-	struct vm_area_struct *existing;
-
-	MA_STATE(mas, &mm->mm_mt, start, start);
-	rcu_read_lock();
-	existing = mas_find(&mas, end - 1);
-	*pprev = mas_prev(&mas, 0);
-	rcu_read_unlock();
-	return existing ? true : false;
-}
-
 /*
  * count_vma_pages_range() - Count the number of pages in a range.
  * @mas: The maple state
@@ -3224,9 +3200,7 @@ oomed:
  */
 int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
 {
-	struct vm_area_struct *prev;
-
-	if (range_has_overlap(mm, vma->vm_start, vma->vm_end, &prev))
+	if (find_vma_intersection(mm, vma->vm_start, vma->vm_end))
 		return -ENOMEM;
 
 	if ((vma->vm_flags & VM_ACCOUNT) &&
@@ -3265,7 +3239,8 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
 	struct vm_area_struct *vma = *vmap;
 	unsigned long vma_start = vma->vm_start;
 	struct mm_struct *mm = vma->vm_mm;
-	struct vm_area_struct *new_vma, *prev;
+	struct vm_area_struct *new_vma;
+	struct vm_area_struct *prev;
 	bool faulted_in_anon_vma = true;
 
 	validate_mm_mt(mm);
@@ -3278,9 +3253,10 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
 		faulted_in_anon_vma = false;
 	}
 
-	if (range_has_overlap(mm, addr, addr + len, &prev))
+	if (find_vma_intersection(mm, addr, addr + len))
 		return NULL;	/* should never get here */
 
+	prev = vma_prev(mm, vma);
 	new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
 			    vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
 			    vma->vm_userfaultfd_ctx);