platform_bionic/linker/Android.mk
Nick Kralevich 468319ce4f Make the linker relocatable.
Previously, the linker always loaded itself into the same
location in memory, which inhibited the effectiveness of Android's
ASLR implementation. Modify the linker code so it can be relocatable
and link itself at runtime.

Change-Id: Ia80273d7a00ff648b4da545f4b69debee6343968
2011-11-11 18:01:53 -08:00

73 lines
1.9 KiB
Makefile

LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES:= \
arch/$(TARGET_ARCH)/begin.S \
linker.c \
linker_environ.c \
linker_format.c \
rt.c \
dlfcn.c \
debugger.c
LOCAL_LDFLAGS := -shared
LOCAL_CFLAGS += -fno-stack-protector
# Set LINKER_DEBUG to either 1 or 0
#
LOCAL_CFLAGS += -DLINKER_DEBUG=0
# we need to access the Bionic private header <bionic_tls.h>
# in the linker; duplicate the HAVE_ARM_TLS_REGISTER definition
# from the libc build
ifeq ($(TARGET_ARCH)-$(ARCH_ARM_HAVE_TLS_REGISTER),arm-true)
LOCAL_CFLAGS += -DHAVE_ARM_TLS_REGISTER
endif
LOCAL_CFLAGS += -I$(LOCAL_PATH)/../libc/private
ifeq ($(TARGET_ARCH),arm)
LOCAL_CFLAGS += -DANDROID_ARM_LINKER
else
ifeq ($(TARGET_ARCH),x86)
LOCAL_CFLAGS += -DANDROID_X86_LINKER
else
ifeq ($(TARGET_ARCH),sh)
LOCAL_CFLAGS += -DANDROID_SH_LINKER
else
$(error Unsupported TARGET_ARCH $(TARGET_ARCH))
endif
endif
endif
LOCAL_MODULE:= linker
LOCAL_STATIC_LIBRARIES := libc_nomalloc
#LOCAL_FORCE_STATIC_EXECUTABLE := true # not necessary when not including BUILD_EXECUTABLE
#
# include $(BUILD_EXECUTABLE)
#
# Instead of including $(BUILD_EXECUTABLE), we execute the steps to create an executable by
# hand, as we want to insert an extra step that is not supported by the build system, and
# is probably specific the linker only, so there's no need to modify the build system for
# the purpose.
LOCAL_MODULE_CLASS := EXECUTABLES
LOCAL_MODULE_SUFFIX := $(TARGET_EXECUTABLE_SUFFIX)
# we don't want crtbegin.o (because we have begin.o), so unset it
# just for this module
LOCAL_NO_CRT := true
include $(BUILD_SYSTEM)/dynamic_binary.mk
$(linked_module): $(TARGET_CRTBEGIN_STATIC_O) $(all_objects) $(all_libraries) $(TARGET_CRTEND_O)
$(transform-o-to-static-executable)
@echo "target PrefixSymbols: $(PRIVATE_MODULE) ($@)"
$(hide) $(TARGET_OBJCOPY) --prefix-symbols=__dl_ $@
#
# end of BUILD_EXECUTABLE hack
#