compel: Initial commit for standalone tool

The compel component is a replacement for several aspects of CRIU
functionality: binary blobs generation for PIE parasite/restore code,
and a library for parasite code injection and execution (to be implemented).

In the commit we rather shuffle compel into own directory and
use it for

1) Fetching cflags when compiling PIE blobs
2) Use its "piegen" functionality to generate blobs themselves.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

Makefile

@@ -127,7 +127,7 @@ endif
 CFLAGS			+= $(WARNINGS) $(DEFINES) -iquote include/
 
 # Default target
-all: criu lib
+all: compel criu lib
 .PHONY: all
 
 #
@@ -201,6 +201,9 @@ $(eval $(call gen-built-in,images))
 
 .PHONY: .FORCE
 
+# Compel get used by CRIU, build it earlier
+$(eval $(call gen-built-in,compel))
+
 #
 # Next the socket CR library
 #
@@ -222,9 +225,9 @@ $(SOCCR_A): |soccr/built-in.o
 #
 # But note that we're already included
 # the nmk so we can reuse it there.
-criu/%: images/built-in.o $(VERSION_HEADER) $(CONFIG_HEADER) .FORCE
+criu/%: images/built-in.o compel/compel $(VERSION_HEADER) $(CONFIG_HEADER) .FORCE
 	$(Q) $(MAKE) $(build)=criu $@
-criu: images/built-in.o $(SOCCR_A) $(VERSION_HEADER) $(CONFIG_HEADER)
+criu: images/built-in.o compel/compel $(SOCCR_A) $(VERSION_HEADER) $(CONFIG_HEADER)
 	$(Q) $(MAKE) $(build)=criu all
 .PHONY: criu
 
@@ -248,6 +251,7 @@ clean: subclean
 	$(Q) $(MAKE) $(build)=criu $@
 	$(Q) $(MAKE) $(build)=soccr $@
 	$(Q) $(MAKE) $(build)=lib $@
+	$(Q) $(MAKE) $(build)=compel $@
 .PHONY: clean
 
 # mrproper depends on clean in nmk
@@ -256,6 +260,7 @@ mrproper: subclean
 	$(Q) $(MAKE) $(build)=criu $@
 	$(Q) $(MAKE) $(build)=soccr $@
 	$(Q) $(MAKE) $(build)=lib $@
+	$(Q) $(MAKE) $(build)=compel $@
 	$(Q) $(RM) $(CONFIG_HEADER)
 	$(Q) $(RM) $(SOCCR_CONFIG)
 	$(Q) $(RM) $(VERSION_HEADER)

Makefile.versions

@@ -23,3 +23,8 @@ SOCCR_SO_VERSION_MAJOR	:= 1
 SOCCR_SO_VERSION_MINOR	:= 0
 
 export SOCCR_SO_VERSION_MAJOR SOCCR_SO_VERSION_MINOR
+
+COMPEL_SO_VERSION_MAJOR	:= 1
+COMPEL_SO_VERSION_MINOR	:= 0
+
+export COMPEL_SO_VERSION_MAJOR COMPEL_SO_VERSION_MINOR

compel/Makefile

+include $(SRC_DIR)/Makefile.versions
+
+ccflags-y	+= -iquote criu/include
+ccflags-y	+= -iquote compel/include
+ccflags-y	+= -DCOMPEL_VERSION=\"$(COMPEL_SO_VERSION_MAJOR).$(COMPEL_SO_VERSION_MINOR)\"
+
+host-ccflags-y	+= $(filter-out -pg $(CFLAGS-GCOV),$(ccflags-y))
+HOSTCFLAGS	+= $(filter-out -pg $(CFLAGS-GCOV),$(WARNINGS) $(DEFINES))
+HOSTLDFLAGS	+= $(filter-out -pg $(CFLAGS-GCOV),$(LDFLAGS))
+
+hostprogs-y	+= compel
+compel-objs	+= src/main.o
+
+ifneq ($(filter ia32 x86, $(ARCH)),)
+compel-objs	+= src/elf-x86-32.o
+compel-objs	+= src/elf-x86-64.o
+endif
+ifeq ($(SRCARCH),ppc64)
+compel-objs	+= src/elf-ppc64.o
+endif

criu/Makefile

@@ -45,18 +45,6 @@ ARCH-LIB		:= $(ARCH_DIR)/crtools.built-in.o
 $(ARCH-LIB): syscalls_lib
 	$(Q) $(MAKE) $(build)=$(ARCH_DIR) all
 
-#
-# piegen tool needed for PIE code.
-ifeq ($(piegen-y),y)
-piegen-bin		:= criu/pie/piegen/piegen
-
-criu/pie/piegen/%: $(CONFIG_HEADER)
-	$(Q) CC=$(HOSTCC) LD=$(HOSTLD) CFLAGS="$(ccflags-y) $(HOSTCFLAGS) $(WARNINGS) $(DEFINES)" $(MAKE) $(build)=criu/pie/piegen $@
-$(piegen-bin): criu/pie/piegen/built-in.o
-	$(call msg-link, $@)
-	$(Q) $(HOSTCC) $(HOSTCFLAGS) $^ $(LDFLAGS) -o $@
-endif
-
 #
 # PIE library code.
 criu/pie/lib.a: $(ARCH-LIB)
@@ -64,7 +52,7 @@ criu/pie/lib.a: $(ARCH-LIB)
 
 #
 # PIE code blobs themseves.
-pie: $(piegen-bin) criu/pie/lib.a
+pie: criu/pie/lib.a
 	$(Q) $(MAKE) $(build)=criu/pie all
 .PHONY: pie
 
@@ -98,14 +86,12 @@ $(obj)/criu: $(PROGRAM-BUILTINS)
 subclean:
 	$(Q) $(RM) $(obj)/*.{gcda,gcno,gcov}
 	$(Q) $(RM) $(obj)/pie/*.{gcda,gcno,gcov}
-	$(Q) $(RM) $(obj)/pie/piegen/*.{gcda,gcno,gcov}
 	$(Q) $(RM) -r $(obj)/gcov
 	$(Q) $(MAKE) $(call build-as,Makefile.syscalls,$(ARCH_DIR)) clean
 	$(Q) $(MAKE) $(build)=$(ARCH_DIR) clean
 	$(Q) $(MAKE) $(call build-as,Makefile.library,$(PIE_DIR)) clean
 	$(Q) $(MAKE) $(call build-as,Makefile.crtools,criu) clean
 	$(Q) $(MAKE) $(build)=$(PIE_DIR) clean
-	$(Q) $(MAKE) $(build)=$(PIE_DIR)/piegen clean
 .PHONY: subclean
 cleanup-y      += $(obj)/criu
 clean: subclean
@@ -118,7 +104,6 @@ subproper:
 	$(Q) $(MAKE) $(call build-as,Makefile.library,$(PIE_DIR)) mrproper
 	$(Q) $(MAKE) $(call build-as,Makefile.crtools,criu) mrproper
 	$(Q) $(MAKE) $(build)=$(PIE_DIR) mrproper
-	$(Q) $(MAKE) $(build)=$(PIE_DIR)/piegen mrproper
 .PHONY: subproper
 mrproper: subproper
 

criu/pie/Makefile

@@ -16,7 +16,7 @@ restorer-obj-e		+= ./$(ARCH_DIR)/syscalls.built-in.o
 # project.
 #
 CFLAGS			:= $(filter-out -pg $(CFLAGS-GCOV),$(CFLAGS))
-CFLAGS			+= -iquote $(SRC_DIR)/criu/pie/piegen
+CFLAGS			+= -iquote $(SRC_DIR)/compel/include
 CFLAGS			+= -iquote $(SRC_DIR)/criu/arch/$(ARCH)/include
 CFLAGS			+= -iquote $(SRC_DIR)/criu/include
 CFLAGS			+= -iquote $(SRC_DIR)/include
@@ -25,10 +25,9 @@ CFLAGS			+= -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0
 CFLAGS			+= -Wp,-U_FORTIFY_SOURCE -Wp,-D_FORTIFY_SOURCE=0
 
 
-ifneq ($(filter-out ia32,$(ARCH)),)
-        ccflags-y	+= -DCR_NOGLIBC -fpie -Wa,--noexecstack -fno-stack-protector
-else
-        ccflags-y	+= -DCR_NOGLIBC -fno-pic -Wa,--noexecstack -fno-stack-protector
+ccflags-y		+= -DCR_NOGLIBC
+ifneq ($(filter-out clean mrproper,$(MAKECMDGOALS)),)
+	ccflags-y	+= $(shell $(SRC_DIR)/compel/compel --arch=$(ARCH) cflags)
 endif
 
 ifeq ($(SRCARCH),arm)
@@ -76,9 +75,9 @@ $(obj)/%.built-in.bin.o: $(obj)/%.built-in.o $(obj)/lib.a $(obj)/$(PIELDS)
 	$(call msg-gen, $@)
 	$(Q) $(LD) -r -T $(obj)/$(PIELDS) -o $@ $< $(obj)/lib.a
 
-$(obj)/%-blob.h: $(obj)/%.built-in.bin.o $(obj)/$(PIELDS) criu/pie/piegen
+$(obj)/%-blob.h: $(obj)/%.built-in.bin.o $(obj)/$(PIELDS) compel/compel
 	$(call msg-gen, $@)
-	$(Q) criu/pie/piegen/piegen piegen -f $< -v $(call target-name,$@)_relocs -p $(call target-name,$@)_blob_offset__ -s $(call target-name,$@)_blob -o $@ $(piegen_stdout)
+	$(Q) compel/compel piegen -f $< -v $(call target-name,$@)_relocs -p $(call target-name,$@)_blob_offset__ -s $(call target-name,$@)_blob -o $@ $(piegen_stdout)
 
 else
 

criu/pie/pie-relocs.c

@@ -17,7 +17,7 @@
 #include "log.h"
 
 #include "common/compiler.h"
-#include "piegen/uapi/types.h"
+#include "compel/include/uapi/types.h"
 #include "common/bug.h"
 
 __maybe_unused void elf_relocs_apply(void *mem, void *vbase, size_t size, elf_reloc_t *elf_relocs, size_t nr_relocs)

criu/pie/pie-relocs.h

 #ifndef __PIE_RELOCS_H__
 #define __PIE_RELOCS_H__
 
-#include "piegen/uapi/types.h"
+#include "compel/include/uapi/types.h"
 
 #include "common/compiler.h"
 #include "config.h"

criu/pie/piegen/Makefile

-CFLAGS += -iquote pie/piegen
-
-obj-y += main.o
-ifneq ($(filter ia32 x86, $(ARCH)),)
-obj-y += elf-x86-32.o
-obj-y += elf-x86-64.o
-endif
-ifeq ($(SRCARCH),ppc64)
-obj-y += elf-ppc64.o
-endif
-
-cleanup-y += $(obj)/piegen
-cleanup-y += $(obj)/*.o
-
-ifneq ($(MAKECMDGOALS),clean)
-ifneq ($(MAKECMDGOALS),mrproper)
-incdeps := y
-endif
-endif