diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 75232ad..bc6d85c 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -369,7 +369,7 @@
 	kunmap_atomic(from);
 }
 
-static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len)
+static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len)
 {
 	char *to = kmap_atomic(page);
 	memcpy(to + offset, from, len);
@@ -383,9 +383,9 @@
 	kunmap_atomic(addr);
 }
 
-size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
+size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 {
-	char *from = addr;
+	const char *from = addr;
 	if (unlikely(bytes > i->count))
 		bytes = i->count;
 
@@ -704,10 +704,10 @@
 }
 EXPORT_SYMBOL(csum_and_copy_from_iter);
 
-size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum,
+size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
 			     struct iov_iter *i)
 {
-	char *from = addr;
+	const char *from = addr;
 	__wsum sum, next;
 	size_t off = 0;
 	if (unlikely(bytes > i->count))