When searching for a vma within a range, it is easier to use the maple
tree interface. This means the find_vma() call changes to a special
case of the find_vma_intersection(). Exported for kvm module.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
include/linux/mm.h | 10 ++--------
mm/mmap.c | 41 ++++++++++++++++++++++++++++-------------
2 files changed, 30 insertions(+), 21 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6cc8825f26414..93166e22c988f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2651,14 +2651,8 @@ extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned lon
/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
NULL if none. Assume start_addr < end_addr. */
-static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
-{
- struct vm_area_struct * vma = find_vma(mm,start_addr);
-
- if (vma && end_addr <= vma->vm_start)
- vma = NULL;
- return vma;
-}
+extern struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
+ unsigned long start_addr, unsigned long end_addr);
static inline unsigned long vm_start_gap(struct vm_area_struct *vma)
{
diff --git a/mm/mmap.c b/mm/mmap.c
index dc7a742fbe131..21342ab85b752 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2048,32 +2048,47 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
EXPORT_SYMBOL(get_unmapped_area);
-/**
- * find_vma() - Find the VMA for a given address, or the next vma.
- * @mm The mm_struct to check
- * @addr: The address
+/*
+ * find_vma_intersection - Find the first vma between [@start, @end)
+ * @mm: The mm_struct to use.
+ * @start: The start address
+ * @end: The end address
*
- * Returns: The VMA assoicated with addr, or the next vma.
- * May return NULL in the case of no vma at addr or above.
+ * Returns: The VMA associated with the @start or the next VMA within the range.
*/
-struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
+struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
+ unsigned long start_addr,
+ unsigned long end_addr)
{
struct vm_area_struct *vma;
- MA_STATE(mas, &mm->mm_mt, start_addr, start_addr);
+ unsigned long addr = start_addr;
/* Check the cache first. */
- vma = vmacache_find(mm, addr);
+ vma = vmacache_find(mm, start_addr);
if (likely(vma))
return vma;
- rcu_read_lock();
- vma = mas_find(&mas, end_addr - 1);
- rcu_read_unlock();
+ vma = mt_find(&mm->mm_mt, &addr, end_addr - 1);
if (vma)
- vmacache_update(addr, vma);
+ vmacache_update(start_addr, vma);
return vma;
}
+EXPORT_SYMBOL(find_vma_intersection);
+
+/**
+ * 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)
+{
+ // Note find_vma_intersection will decrease 0 to underflow to ULONG_MAX
+ return find_vma_intersection(mm, addr, 0);
+}
EXPORT_SYMBOL(find_vma);
/**
--
2.28.0
