s390/purgatory: do not build purgatory with kcov, kasan and friends

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>

diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile
index 13e9a5dc0a07cb7e65cc53fc4d120d3b72266e8b..c57f8c40e992685812170f3db796256b7e620934 100644 (file)
--- 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

diff --git a/arch/s390/purgatory/string.c b/arch/s390/purgatory/string.c
new file mode 100644 (file)
index 0000000..c98c22a
--- /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"