From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Wed, 18 Dec 2019 09:34:57 +0100
Subject: s390/purgatory: do not build purgatory with kcov, kasan and friends
Git-commit: c23587c92f6e3260fe3b82bb75b38aa2553b9468
Patch-mainline: v5.5-rc3
References: bsc#1179603 LTC#190152

the purgatory must not rely on functions from the "old" kernel,
so we must disable kasan and friends. We also need to have a
separate copy of string.c as the default does not build memcmp
with KASAN.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 arch/s390/purgatory/Makefile |    6 ++++--
 arch/s390/purgatory/string.c |    3 +++
 2 files changed, 7 insertions(+), 2 deletions(-)

--- a/arch/s390/purgatory/Makefile
+++ b/arch/s390/purgatory/Makefile
@@ -15,8 +15,10 @@ CFLAGS_sha256.o := -D__DISABLE_EXPORTS
 $(obj)/mem.o: $(srctree)/arch/s390/lib/mem.S FORCE
 	$(call if_changed_rule,as_o_S)
 
-$(obj)/string.o: $(srctree)/arch/s390/lib/string.c FORCE
-	$(call if_changed_rule,cc_o_c)
+KCOV_INSTRUMENT := n
+GCOV_PROFILE := n
+UBSAN_SANITIZE := n
+KASAN_SANITIZE := n
 
 KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes
 KBUILD_CFLAGS += -Wno-pointer-sign -Wno-sign-compare
--- /dev/null
+++ b/arch/s390/purgatory/string.c
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0
+#define __HAVE_ARCH_MEMCMP	/* arch function */
+#include "../lib/string.c"