linux/arch/um/Makefile
Florian Fainelli f44f1e7da7 um: Avoid longjmp/setjmp symbol clashes with libpthread.a
Building a statically linked UML kernel on a Centos 6.9 host resulted in
the following linking failure (GCC 4.4, glibc-2.12):

/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o):
In function `siglongjmp':
(.text+0x8490): multiple definition of `longjmp'
arch/x86/um/built-in.o:/local/users/fainelli/openwrt/trunk/build_dir/target-x86_64_musl/linux-uml/linux-4.4.69/arch/x86/um/setjmp_64.S:44:
first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o):
In function `sem_open':
(.text+0x77cd): warning: the use of `mktemp' is dangerous, better use
`mkstemp'
collect2: ld returned 1 exit status
make[4]: *** [vmlinux] Error 1

Adopt a solution similar to the one done for vmap where we define
longjmp/setjmp to be kernel_longjmp/setjmp. In the process, make sure we
do rename the functions in arch/x86/um/setjmp_*.S accordingly.

Fixes: a7df4716d1 ("um: link with -lpthread")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-07-05 23:30:50 +02:00

173 lines
5.2 KiB
Makefile

#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies.
#
# Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
# Licensed under the GPL
#
# select defconfig based on actual architecture
ifeq ($(SUBARCH),x86)
ifeq ($(shell uname -m),x86_64)
KBUILD_DEFCONFIG := x86_64_defconfig
else
KBUILD_DEFCONFIG := i386_defconfig
endif
else
KBUILD_DEFCONFIG := $(SUBARCH)_defconfig
endif
ARCH_DIR := arch/um
OS := $(shell uname -s)
# We require bash because the vmlinux link and loader script cpp use bash
# features.
SHELL := /bin/bash
filechk_gen_header = $<
core-y += $(ARCH_DIR)/kernel/ \
$(ARCH_DIR)/drivers/ \
$(ARCH_DIR)/os-$(OS)/
MODE_INCLUDE += -I$(srctree)/$(ARCH_DIR)/include/shared/skas
HEADER_ARCH := $(SUBARCH)
ifneq ($(filter $(SUBARCH),x86 x86_64 i386),)
HEADER_ARCH := x86
endif
ifdef CONFIG_64BIT
KBUILD_CFLAGS += -mcmodel=large
endif
HOST_DIR := arch/$(HEADER_ARCH)
include $(ARCH_DIR)/Makefile-skas
include $(HOST_DIR)/Makefile.um
core-y += $(HOST_DIR)/um/
SHARED_HEADERS := $(ARCH_DIR)/include/shared
ARCH_INCLUDE := -I$(srctree)/$(SHARED_HEADERS)
ARCH_INCLUDE += -I$(srctree)/$(HOST_DIR)/um/shared
KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/um
# -Dvmap=kernel_vmap prevents anything from referencing the libpcap.o symbol so
# named - it's a common symbol in libpcap, so we get a binary which crashes.
#
# Same things for in6addr_loopback and mktime - found in libc. For these two we
# only get link-time error, luckily.
#
# -Dlongjmp=kernel_longjmp prevents anything from referencing the libpthread.a
# embedded copy of longjmp, same thing for setjmp.
#
# These apply to USER_CFLAGS to.
KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ \
$(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap \
-Dlongjmp=kernel_longjmp -Dsetjmp=kernel_setjmp \
-Din6addr_loopback=kernel_in6addr_loopback \
-Din6addr_any=kernel_in6addr_any -Dstrrchr=kernel_strrchr
KBUILD_AFLAGS += $(ARCH_INCLUDE)
USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \
$(ARCH_INCLUDE) $(MODE_INCLUDE) $(filter -I%,$(CFLAGS)) \
-D_FILE_OFFSET_BITS=64 -idirafter $(srctree)/include \
-idirafter $(obj)/include -D__KERNEL__ -D__UM_HOST__
#This will adjust *FLAGS accordingly to the platform.
include $(ARCH_DIR)/Makefile-os-$(OS)
KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/include \
-I$(srctree)/$(HOST_DIR)/include/uapi \
-I$(objtree)/$(HOST_DIR)/include/generated \
-I$(objtree)/$(HOST_DIR)/include/generated/uapi
# -Derrno=kernel_errno - This turns all kernel references to errno into
# kernel_errno to separate them from the libc errno. This allows -fno-common
# in KBUILD_CFLAGS. Otherwise, it would cause ld to complain about the two different
# errnos.
# These apply to kernelspace only.
#
# strip leading and trailing whitespace to make the USER_CFLAGS removal of these
# defines more robust
KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
-Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES))
KBUILD_CFLAGS += $(KERNEL_DEFINES)
PHONY += linux
all: linux
linux: vmlinux
@echo ' LINK $@'
$(Q)ln -f $< $@
define archhelp
echo '* linux - Binary kernel image (./linux) - for backward'
echo ' compatibility only, this creates a hard link to the'
echo ' real kernel binary, the "vmlinux" binary you'
echo ' find in the kernel root.'
endef
KBUILD_KCONFIG := $(HOST_DIR)/um/Kconfig
archheaders:
$(Q)$(MAKE) KBUILD_SRC= ARCH=$(HEADER_ARCH) archheaders
archprepare: include/generated/user_constants.h
LINK-$(CONFIG_LD_SCRIPT_STATIC) += -static
LINK-$(CONFIG_LD_SCRIPT_DYN) += -Wl,-rpath,/lib
CFLAGS_NO_HARDENING := $(call cc-option, -fno-PIC,) $(call cc-option, -fno-pic,) \
$(call cc-option, -fno-stack-protector,) \
$(call cc-option, -fno-stack-protector-all,)
# Options used by linker script
export LDS_START := $(START)
export LDS_ELF_ARCH := $(ELF_ARCH)
export LDS_ELF_FORMAT := $(ELF_FORMAT)
# The wrappers will select whether using "malloc" or the kernel allocator.
LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
LD_FLAGS_CMDLINE = $(foreach opt,$(LDFLAGS),-Wl,$(opt))
# Used by link-vmlinux.sh which has special support for um link
export CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE)
# When cleaning we don't include .config, so we don't include
# TT or skas makefiles and don't clean skas_ptregs.h.
CLEAN_FILES += linux x.i gmon.out
archclean:
@find . \( -name '*.bb' -o -name '*.bbg' -o -name '*.da' \
-o -name '*.gcov' \) -type f -print | xargs rm -f
# Generated files
$(HOST_DIR)/um/user-offsets.s: __headers FORCE
$(Q)$(MAKE) $(build)=$(HOST_DIR)/um $@
define filechk_gen-asm-offsets
(set -e; \
echo "/*"; \
echo " * DO NOT MODIFY."; \
echo " *"; \
echo " * This file was generated by arch/$(ARCH)/Makefile"; \
echo " *"; \
echo " */"; \
echo ""; \
sed -ne "/^->/{s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; s:->::; p;}"; \
echo ""; )
endef
include/generated/user_constants.h: $(HOST_DIR)/um/user-offsets.s
$(call filechk,gen-asm-offsets)
export SUBARCH USER_CFLAGS CFLAGS_NO_HARDENING OS DEV_NULL_PATH