From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Using the maple tree interface mt_find() will handle the RCU locking and
will start searching at the address up to the limit, ULONG_MAX in this
case.
Add kernel documentation to this API.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
mm/mmap.c | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index e891977293fa..899747a75d5c 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2487,10 +2487,16 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
EXPORT_SYMBOL(get_unmapped_area);
-/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
+/**
+ * find_vma() - Find the VMA for a given address, or the next vma.
+ * @mm: The mm_struct to check
+ * @addr: The address
+ *
+ * Returns: The VMA associated with addr, or the next vma.
+ * May return %NULL in the case of no vma at addr or above.
+ */
struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
{
- struct rb_node *rb_node;
struct vm_area_struct *vma;
mmap_assert_locked(mm);
@@ -2499,24 +2505,10 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
if (likely(vma))
return vma;
- rb_node = mm->mm_rb.rb_node;
-
- while (rb_node) {
- struct vm_area_struct *tmp;
-
- tmp = rb_entry(rb_node, struct vm_area_struct, vm_rb);
-
- if (tmp->vm_end > addr) {
- vma = tmp;
- if (tmp->vm_start <= addr)
- break;
- rb_node = rb_node->rb_left;
- } else
- rb_node = rb_node->rb_right;
- }
-
+ vma = mt_find(&mm->mm_mt, &addr, ULONG_MAX);
if (vma)
vmacache_update(addr, vma);
+
return vma;
}
EXPORT_SYMBOL(find_vma);
--
2.30.2
