mm: avoid rewalk in mmap_region
If the iterator has moved to the previous entry, then step forward one
range, back to the gap.
Link: https://lkml.kernel.org/r/20230518145544.1722059-36-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vernon Yang <vernon2gm@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/mmap.c b/mm/mmap.c
index 19d3c84..44be7fd 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2606,6 +2606,9 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
}
cannot_expand:
+ if (prev)
+ vma_iter_next_range(&vmi);
+
/*
* Determine the object being mapped and call the appropriate
* specific mapper. the address has already been validated, but
