use some linker magic to avoid issues with symbol versioning

Author: Kyle-Kyle

Makefile

@@ -1,31 +1,70 @@
-.PHONY: help clean all test
+.PHONY: help clean distclean all test
 
 VERSIONS := 2.23 2.24 2.27 2.31 2.32 2.33 2.34 2.35 2.36 2.37 2.38 2.39
 TECH_BINS := $(patsubst %.c,%,$(wildcard glibc_*/*.c))
 BASE_BINS := $(patsubst %.c,%,$(wildcard *.c))
+DOWNLOADED := glibc-all-in-one/libs glibc-all-in-one/debs
 BINS := $(TECH_BINS) $(BASE_BINS)
+ARCH := amd64
+
+ifeq ($(H2H_USE_SYSTEM_LIBC),)
+H2H_USE_SYSTEM_LIBC := Y
+endif
 
 help:
 	@echo 'make help                    - show this message'
 	@echo 'make base                    - build all base binaries, namely `malloc_playground`, `first_fit`, `calc_tcache_idx`'
-	@echo 'make <version>               - build all the techniques for the specific version. e.g. `make v2.39`'
+	@echo 'make <version>               - build all the techniques for a specific version. e.g. `make v2.39`'
 	@echo 'make clean                   - remove all built binaries'
+	@echo 'make distclean               - remove all built binaries and downloaded libcs'
 	@echo 'make all                     - build all binaries'
-	@echo 'make test version=<version>  - test run all techniques for the specific version. e.g. `make test version=2.39`'
+	@echo 'make test version=<version>  - test run all techniques for a specific version. e.g. `make test version=2.39`'
 
 CFLAGS += -std=c99 -g -Wno-unused-result -Wno-free-nonheap-object
 LDLIBS += -ldl
 
 base: $(BASE_BINS)
 
+# populate the download_glibc_<version> rules
+$(addprefix download_glibc_, $(VERSIONS)):
+	@echo $@
+
+	version=$(patsubst download_glibc_%,%,$@); \
+	libc=$$(cat glibc-all-in-one/list | grep "$$version" | grep "$(ARCH)" | head -n 1); \
+	old_libc=$$(cat glibc-all-in-one/old_list | grep "$(version)" | grep "$(ARCH)" | head -n 1); \
+	if [ -z $$libc ]; then libc=$$old_libc; script="download_old"; else libc=$$libc; script="download"; fi; \
+	cd glibc-all-in-one; \
+	rm -rf libs/$$libc; \
+	./$$script $$libc
+
+# populate the make <version> rules
+ifeq ($(H2H_USE_SYSTEM_LIBC),Y)
 $(foreach version,$(VERSIONS),$(eval v$(version): $(patsubst %.c,%,$(wildcard glibc_$(version)/*.c))))
+else
+$(foreach version,$(VERSIONS),$(eval v$(version): download_glibc_$(version) $(patsubst %.c,%,$(wildcard glibc_$(version)/*.c)) ))
+endif
+
+# the compilation rules
+%: %.c
+	version=$(word 1, $(subst /, ,$(patsubst glibc_%,%,$@))); \
+	if [ "$(H2H_USE_SYSTEM_LIBC)" = "Y" ]; \
+	then \
+		$(CC) $(CFLAGS) $(DIR_CFLAGS_$(@D)) $^ -o $@ $(LDLIBS); \
+	else \
+		$(CC) $(CFLAGS) $(DIR_CFLAGS_$(@D)) $^ -o $@ $(LDLIBS) -Xlinker -rpath=$$(realpath glibc-all-in-one/libs/$$version*) -Xlinker -I$$(realpath glibc-all-in-one/libs/$$version*/ld-linux-x86-64.so.2) -Xlinker $$(realpath glibc-all-in-one/libs/$$version*/libc.so.6) -Xlinker $$(realpath glibc-all-in-one/libs/$$version*/libdl.so.2) -include ./utils/wrapper.h -Wl,--wrap=__libc_start_main -Wl,--wrap=dlsym; \
+	fi
 
 all: $(BINS)
 
 clean:
 	@rm -f $(BINS)
 	@echo "all the built binaries are removed."
 
+distclean:
+	@rm -f $(BINS)
+	@rm -rf $(DOWNLOADED)
+	@echo "all the built binaries and all downloaded libcs are removed."
+
 define test_poc =
 echo $(poc)
 for i in $$(seq 0 20);\

Makefile_ld

@@ -0,0 +1,29 @@
+// hook __libc_start_main
+__asm__(".symver __libc_start_main_old,__libc_start_main@GLIBC_2.2.5");
+int __libc_start_main_old(int (*main) (int, char **, char **),
+                          int argc,
+                          char **argv,
+                          __typeof (main) init,
+                          void (*fini) (void),
+                          void (*rtld_fini) (void),
+                          void *stack_end);
+
+int __wrap___libc_start_main(int (*main) (int, char **, char **),
+                             int argc,
+                             char **argv,
+                             __typeof (main) init,
+                             void (*fini) (void),
+                             void (*rtld_fini) (void),
+                             void *stack_end)
+{
+  return __libc_start_main_old(main, argc, argv, init, fini, rtld_fini, stack_end);
+}
+
+// hook dlsym
+__asm__(".symver dlsym_old,dlsym@GLIBC_2.2.5");
+//__asm__(".symver dlsym_old,__libc_dlsym@GLIBC_PRIVATE");
+void *dlsym_old(void *handle, const char *symbol);
+void *__wrap_dlsym(void *handle, const char *symbol)
+{
+	return dlsym_old(handle, symbol);
+}