v4.19.13 snapshot.
diff --git a/kernel/elfcore.c b/kernel/elfcore.c
new file mode 100644
index 0000000..fc482c8
--- /dev/null
+++ b/kernel/elfcore.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/elf.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/binfmts.h>
+
+Elf_Half __weak elf_core_extra_phdrs(void)
+{
+ return 0;
+}
+
+int __weak elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
+{
+ return 1;
+}
+
+int __weak elf_core_write_extra_data(struct coredump_params *cprm)
+{
+ return 1;
+}
+
+size_t __weak elf_core_extra_data_size(void)
+{
+ return 0;
+}