s390: Move -msoft-float/-fno-optimize-sibling-calls into compel Makefiles

We currently define "CFLAGS += -msoft-float -fno-optimize-sibling-calls"
in Makefile.compel.

Makefile.compel is included into the toplevel Makefile and so changes
CFLAGS which are exported to all criu and zdtm Makefiles.

We must not use -msoft-float outside the compel files. E.g. otherwise for
zdtm we get the following build error:

uptime_grow.o: In function `main':
/tmp/2/criu/test/zdtm/static/uptime_grow.c:36: undefined reference to `__floatdidf'
/tmp/2/criu/test/zdtm/static/uptime_grow.c:36: undefined reference to `__muldf3'
/tmp/2/criu/test/zdtm/static/uptime_grow.c:36: undefined reference to `__floatdidf'
/tmp/2/criu/test/zdtm/static/uptime_grow.c:36: undefined reference to `__adddf3

Fix this and move the CFLAGS definition to the compel Makefiles.
We do this by defining a new flag CFLAGS_PIE that is only used for pie code.
Reported-by: Adrian Reber <areber@redhat.com>
Suggested-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Tested-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Makefile

@@ -65,12 +65,24 @@ ifeq ($(ARCH),x86)
         DEFINES		:= -DCONFIG_X86_64
 endif
 
+#
+# CFLAGS_PIE:
+#
+# We assume that compel code does not change floating point registers.
+# On s390 gcc uses fprs to cache gprs. Therefore disable floating point
+# with -msoft-float.
+#
+# Also ensure with -fno-optimize-sibling-calls that we don't create GOT
+# (Global Offset Table) relocations with gcc compilers that don't have
+# commit "S/390: Fix 64 bit sibcall".
 ifeq ($(ARCH),s390)
         ARCH		:= s390
         SRCARCH		:= s390
         VDSO		:= y
         DEFINES		:= -DCONFIG_S390
+        CFLAGS_PIE	:= -msoft-float -fno-optimize-sibling-calls
 endif
+export CFLAGS_PIE
 
 LDARCH ?= $(SRCARCH)
 export LDARCH VDSO

Makefile.compel

@@ -70,13 +70,3 @@ compel/$(LIBCOMPEL_SO): compel/$(LIBCOMPEL_A)
 compel-install-targets	+= compel/$(LIBCOMPEL_SO)
 compel-install-targets	+= compel/compel
 compel-install-targets	+= $(compel-plugins)
-
-#
-# Also ensure with -fno-optimize-sibling-calls that we don't create GOT
-# (Global Offset Table) relocations with gcc compilers that don't have
-# commit "S/390: Fix 64 bit sibcall".
-#
-ifeq ($(ARCH),s390)
-CFLAGS += -msoft-float -fno-optimize-sibling-calls
-HOSTCFLAGS += -msoft-float -fno-optimize-sibling-calls
-endif

compel/Makefile

@@ -11,6 +11,7 @@ ccflags-y		+= -iquote compel/arch/$(ARCH)/src/lib/include
 ccflags-y		+= -iquote compel/include
 ccflags-y		+= -fno-strict-aliasing
 ccflags-y		+= -fPIC
+ccflags-y		+= $(CFLAGS_PIE)
 ldflags-y		+= -r
 
 #

compel/plugins/Makefile

@@ -7,7 +7,9 @@ PLUGIN_ARCH_DIR		:= compel/arch/$(ARCH)/plugins
 #
 # CFLAGS, ASFLAGS, LDFLAGS
 
-#
+# Required for pie code
+ccflags-y		+= $(CFLAGS_PIE)
+
 # UAPI inclusion, referred as <compel/...>
 ccflags-y		+= -I compel/include/uapi
 asflags-y		+= -I compel/include/uapi

criu/pie/Makefile

@@ -2,6 +2,7 @@ target		:= parasite restorer
 
 CFLAGS		:= $(filter-out -pg $(CFLAGS-GCOV) $(CFLAGS-ASAN),$(CFLAGS))
 ccflags-y	+= $(COMPEL_UAPI_INCLUDES)
+ccflags-y	+= $(CFLAGS_PIE)
 ccflags-y	+= -DCR_NOGLIBC
 ccflags-y	+= -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
 ccflags-y	+= -Wp,-U_FORTIFY_SOURCE -Wp,-D_FORTIFY_SOURCE=0
@@ -16,13 +17,6 @@ ifeq ($(SRCARCH),arm)
 	ccflags-y	+= -marm
 endif
 
-# We assume that compel code does not change floating point registers.
-# On s390 gcc uses fprs to cache gprs. Therefore disable floating point
-# with -msoft-float.
-ifeq ($(SRCARCH),s390)
-	ccflags-y	+= -msoft-float
-endif
-
 asflags-y	+= -D__ASSEMBLY__
 
 LDS		:= compel/arch/$(SRCARCH)/scripts/compel-pack.lds.S

criu/pie/Makefile.library

@@ -37,13 +37,9 @@ CFLAGS		:= $(filter-out -pg $(CFLAGS-GCOV) $(CFLAGS-ASAN),$(CFLAGS))
 
 asflags-y		:= -D__ASSEMBLY__
 ccflags-y		+= $(COMPEL_UAPI_INCLUDES)
+ccflags-y		+= $(CFLAGS_PIE)
 
 ifeq ($(SRCARCH),arm)
 	ccflags-y	+= -marm
 endif
-# We assume that compel code does not change floating point registers.
-# On s390 gcc uses fprs to cache gprs. Therefore disable floating point
-# with -msoft-float.
-ifeq ($(SRCARCH),s390)
-	ccflags-y	+= -msoft-float
-endif
+