[PATCH v11 68/69] mm/mmap: drop range_has_overlap() function

[Liam Howlett]

From: "Liam R. Howlett" <Liam.Howlett at Oracle.com>

Since there is no longer a linked list, the range_has_overlap() function
is identical to the find_vma_intersection() function.

Link: https://lkml.kernel.org/r/20220504011345.662299-53-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-69-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
Acked-by: Vlastimil Babka <vbabka at suse.cz>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: David Howells <dhowells at redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy at infradead.org>
Cc: SeongJae Park <sj at kernel.org>
Cc: Will Deacon <will at kernel.org>
Cc: Davidlohr Bueso <dave at stgolabs.net>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
---
 mm/mmap.c | 28 +---------------------------
 1 file changed, 1 insertion(+), 27 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index b494c7e3dcb0..1c35cd0ec4c7 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -437,30 +437,6 @@ 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;
-}
-
 static unsigned long count_vma_pages_range(struct mm_struct *mm,
 		unsigned long addr, unsigned long end)
 {
@@ -3282,9 +3258,7 @@ void exit_mmap(struct mm_struct *mm)
  */
 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) &&
-- 
2.35.1