exec: use flush_icache_user_range in read_code

read_code operates on user addresses.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Link: http://lkml.kernel.org/r/20200515143646.3857579-27-hch@lst.deSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/exec.c

@@ -1059,7 +1059,7 @@ ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
 {
 	ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
 	if (res > 0)
-		flush_icache_range(addr, addr + len);
+		flush_icache_user_range(addr, addr + len);
 	return res;
 }
 EXPORT_SYMBOL(read_code);