[PATCH AUTOSEL 4.19 73/84] s390/purgatory: do not build purgatory with kcov, kasan and friends

[Sasha Levin]

From: Christian Borntraeger <borntraeger@xxxxxxxxxx>

[ Upstream commit c23587c92f6e3260fe3b82bb75b38aa2553b9468 ]

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@xxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Reviewed-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/s390/purgatory/Makefile | 6 ++++--
 arch/s390/purgatory/string.c | 3 +++
 2 files changed, 7 insertions(+), 2 deletions(-)
 create mode 100644 arch/s390/purgatory/string.c

diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile
index ce6a3f75065b..fdccb7689bb9 100644
--- a/arch/s390/purgatory/Makefile
+++ b/arch/s390/purgatory/Makefile
@@ -13,8 +13,10 @@ $(obj)/sha256.o: $(srctree)/lib/sha256.c FORCE
 $(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
 
 LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib
 LDFLAGS_purgatory.ro += -z nodefaultlib
diff --git a/arch/s390/purgatory/string.c b/arch/s390/purgatory/string.c
new file mode 100644
index 000000000000..c98c22a72db7
--- /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"
-- 
2.20.1