diff --git a/MAINTAINERS b/MAINTAINERS
index 61bc5c566552..f1b020588597 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -314,6 +314,7 @@ R:	Mauro Carvalho Chehab <mchehab@kernel.org>
 R:	Shuai Xue <xueshuai@linux.alibaba.com>
 L:	linux-acpi@vger.kernel.org
 F:	drivers/acpi/apei/
+F:	drivers/firmware/efi/cper*
 
 ACPI COMPONENT ARCHITECTURE (ACPICA)
 M:	"Rafael J. Wysocki" <rafael@kernel.org>
@@ -9516,6 +9517,7 @@ F:	arch/arm/boot/compressed/efi-header.S
 F:	arch/x86/platform/efi/
 F:	drivers/firmware/efi/
 F:	include/linux/efi*.h
+X:	drivers/firmware/efi/cper*
 
 EXTERNAL CONNECTOR SUBSYSTEM (EXTCON)
 M:	MyungJoo Ham <myungjoo.ham@samsung.com>
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index 0232bd040f61..bd99802cb0ca 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -162,7 +162,7 @@ int cper_bits_to_str(char *buf, int buf_size, unsigned long bits,
 		len -= size;
 		str += size;
 	}
-	return len - buf_size;
+	return buf_size - len;
 }
 EXPORT_SYMBOL_GPL(cper_bits_to_str);
 
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 55452e61af31..f5ff6e84a9b7 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -819,6 +819,7 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
 		if (tbl) {
 			phys_initrd_start = tbl->base;
 			phys_initrd_size = tbl->size;
+			tbl->base = tbl->size = 0;
 			early_memunmap(tbl, sizeof(*tbl));
 		}
 	}