Signed-off-by: Alexey Romanov <[email protected]>
---
mm/zsmalloc.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 5d5fc04385b8..df381ba891ea 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1564,6 +1564,12 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
d_off += size;
d_size -= size;
+ /* Calling kunmap_atomic(d_addr) is necessary. kunmap_atomic()
+ * calls must occurs in reverse order of calls to kmap_atomic.
+ * So, to call kunmap_atomic(s_addr) we should first call
+ * kunmap_atomic(d_addr). For more details see:
+ * Documentation/mm/highmem
+ */
if (s_off >= PAGE_SIZE) {
kunmap_atomic(d_addr);
kunmap_atomic(s_addr);
--
2.30.1