diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 7b0d05414618..596ca7cc4d7b 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -112,6 +112,11 @@ static void handle_relocs(unsigned long offset)
 	}
 }
 
+static void clear_bss_section(void)
+{
+	memset((void *)vmlinux.default_lma + vmlinux.image_size, 0, vmlinux.bss_size);
+}
+
 void startup_kernel(void)
 {
 	unsigned long random_lma;
@@ -151,6 +156,7 @@ void startup_kernel(void)
 	} else if (__kaslr_offset)
 		memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size);
 
+	clear_bss_section();
 	copy_bootdata();
 	if (IS_ENABLED(CONFIG_RELOCATABLE))
 		handle_relocs(__kaslr_offset);
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 0f255b54b051..7edbbcd8228a 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -10,20 +10,12 @@ CFLAGS_REMOVE_ftrace.o		= $(CC_FLAGS_FTRACE)
 
 # Do not trace early setup code
 CFLAGS_REMOVE_early.o		= $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_early_nobss.o	= $(CC_FLAGS_FTRACE)
 
 endif
 
 GCOV_PROFILE_early.o		:= n
-GCOV_PROFILE_early_nobss.o	:= n
-
 KCOV_INSTRUMENT_early.o		:= n
-KCOV_INSTRUMENT_early_nobss.o	:= n
-
 UBSAN_SANITIZE_early.o		:= n
-UBSAN_SANITIZE_early_nobss.o	:= n
-
-KASAN_SANITIZE_early_nobss.o	:= n
 KASAN_SANITIZE_ipl.o		:= n
 KASAN_SANITIZE_machine_kexec.o	:= n
 
@@ -48,7 +40,7 @@ CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
 obj-y	:= traps.o time.o process.o base.o early.o setup.o idle.o vtime.o
 obj-y	+= processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
-obj-y	+= debug.o irq.o ipl.o dis.o diag.o vdso.o early_nobss.o
+obj-y	+= debug.o irq.o ipl.o dis.o diag.o vdso.o
 obj-y	+= sysinfo.o lgr.o os_info.o machine_kexec.o pgm_check.o
 obj-y	+= runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
 obj-y	+= entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
@@ -90,6 +82,3 @@ obj-$(CONFIG_TRACEPOINTS)	+= trace.o
 # vdso
 obj-y				+= vdso64/
 obj-$(CONFIG_COMPAT_VDSO)	+= vdso32/
-
-chkbss := head64.o early_nobss.o
-include $(srctree)/arch/s390/scripts/Makefile.chkbss
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 6312fed48530..b432d63d0b37 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -32,6 +32,21 @@
 #include <asm/boot_data.h>
 #include "entry.h"
 
+static void __init reset_tod_clock(void)
+{
+	u64 time;
+
+	if (store_tod_clock(&time) == 0)
+		return;
+	/* TOD clock not running. Set the clock to Unix Epoch. */
+	if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
+		disabled_wait();
+
+	memset(tod_clock_base, 0, 16);
+	*(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
+	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
+}
+
 /*
  * Initialize storage key for kernel pages
  */
@@ -301,6 +316,7 @@ static void __init check_image_bootable(void)
 
 void __init startup_init(void)
 {
+	reset_tod_clock();
 	check_image_bootable();
 	time_early_init();
 	init_kernel_storage_key();
diff --git a/arch/s390/kernel/early_nobss.c b/arch/s390/kernel/early_nobss.c
deleted file mode 100644
index 52a3ef959341..000000000000
--- a/arch/s390/kernel/early_nobss.c
+++ /dev/null
@@ -1,45 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- *    Copyright IBM Corp. 2007, 2018
- */
-
-/*
- * Early setup functions which may not rely on an initialized bss
- * section. The last thing that is supposed to happen here is
- * initialization of the bss section.
- */
-
-#include <linux/processor.h>
-#include <linux/string.h>
-#include <asm/sections.h>
-#include <asm/lowcore.h>
-#include <asm/timex.h>
-#include <asm/kasan.h>
-#include "entry.h"
-
-static void __init reset_tod_clock(void)
-{
-	u64 time;
-
-	if (store_tod_clock(&time) == 0)
-		return;
-	/* TOD clock not running. Set the clock to Unix Epoch. */
-	if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
-		disabled_wait();
-
-	memset(tod_clock_base, 0, 16);
-	*(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
-	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
-}
-
-static void __init clear_bss_section(void)
-{
-	memset(__bss_start, 0, __bss_stop - __bss_start);
-}
-
-void __init startup_init_nobss(void)
-{
-	reset_tod_clock();
-	clear_bss_section();
-	kasan_early_init();
-}
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index 5aea1a527443..143ed71221fe 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -34,11 +34,9 @@ ENTRY(startup_continue)
 	larl	%r14,init_task
 	stg	%r14,__LC_CURRENT
 	larl	%r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD
-#
-# Early setup functions that may not rely on an initialized bss section,
-# like moving the initrd. Returns with an initialized bss section.
-#
-	brasl	%r14,startup_init_nobss
+#ifdef CONFIG_KASAN
+	brasl	%r14,kasan_early_init
+#endif
 #
 # Early machine initialization and detection functions.
 #
diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
index a1ec63abfb95..d7c218e8b559 100644
--- a/arch/s390/lib/Makefile
+++ b/arch/s390/lib/Makefile
@@ -11,6 +11,3 @@ lib-$(CONFIG_UPROBES) += probes.o
 # Instrumenting memory accesses to __user data (in different address space)
 # produce false positives
 KASAN_SANITIZE_uaccess.o := n
-
-chkbss := mem.o
-include $(srctree)/arch/s390/scripts/Makefile.chkbss
diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile
index b8a8816d94e7..845e12ac5954 100644
--- a/drivers/s390/char/Makefile
+++ b/drivers/s390/char/Makefile
@@ -49,6 +49,3 @@ obj-$(CONFIG_CRASH_DUMP) += sclp_sdias.o zcore.o
 
 hmcdrv-objs := hmcdrv_mod.o hmcdrv_dev.o hmcdrv_ftp.o hmcdrv_cache.o diag_ftp.o sclp_ftp.o
 obj-$(CONFIG_HMC_DRV) += hmcdrv.o
-
-chkbss := sclp_early_core.o
-include $(srctree)/arch/s390/scripts/Makefile.chkbss