From: Finn Thain <fthain@telegraphics.com.au>
Date: Fri, 21 Dec 2018 17:21:43 +1100 (AEDT)
Subject: Build with -ffreestanding on m68k to avoid
  risky optimizations involving libc
Origin: https://marc.info/?l=linux-m68k&m=154537329920545&w=2

diff --git a/arch/m68k/Makefile b/arch/m68k/Makefile
index 997c9f20ea0f..c318afd15e33 100644
--- a/arch/m68k/Makefile
+++ b/arch/m68k/Makefile
@@ -58,1 +58,1 @@ cpuflags-$(CONFIG_M5206e)	:= $(call cc-option,-mcpu=5206e,-m5200)
 cpuflags-$(CONFIG_M5206)	:= $(call cc-option,-mcpu=5206,-m5200)

 KBUILD_AFLAGS += $(cpuflags-y)
-KBUILD_CFLAGS += $(cpuflags-y) -pipe
+KBUILD_CFLAGS += $(cpuflags-y)
 ifdef CONFIG_MMU
 # without -fno-strength-reduce the 53c7xx.c driver fails ;-(
 KBUILD_CFLAGS += -fno-strength-reduce -ffixed-a2
@@ -69,2 +69,2 @@ KBUILD_CFLAGS += -D__uClinux__
 KBUILD_AFLAGS += -D__uClinux__
 endif

+KBUILD_CFLAGS += -pipe -ffreestanding
+
 KBUILD_LDFLAGS := -m m68kelf
 KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/m68k/kernel/module.lds