From 8859b0da5aac28e4e9651c8971e7af344f8ffec1 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Tue, 10 Nov 2020 17:43:07 +0100 Subject: [PATCH] tools/bpftool: Fix cross-build The bpftool build first creates an intermediate binary, executed on the host, to generate skeletons required by the final build. When cross-building bpftool for an architecture different from the host, the intermediate binary should be built using the host compiler (gcc) and the final bpftool using the cross compiler (e.g. aarch64-linux-gnu-gcc). Generate the intermediate objects into the bootstrap/ directory using the host toolchain. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201110164310.2600671-4-jean-philippe@linaro.org --- tools/bpf/bpftool/Makefile | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 1358c093b812..d566bced135e 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -19,24 +19,37 @@ BPF_DIR = $(srctree)/tools/lib/bpf/ ifneq ($(OUTPUT),) LIBBPF_OUTPUT = $(OUTPUT)/libbpf/ LIBBPF_PATH = $(LIBBPF_OUTPUT) + BOOTSTRAP_OUTPUT = $(OUTPUT)/bootstrap/ else + LIBBPF_OUTPUT = LIBBPF_PATH = $(BPF_DIR) + BOOTSTRAP_OUTPUT = $(CURDIR)/bootstrap/ endif LIBBPF = $(LIBBPF_PATH)libbpf.a +LIBBPF_BOOTSTRAP_OUTPUT = $(BOOTSTRAP_OUTPUT)libbpf/ +LIBBPF_BOOTSTRAP = $(LIBBPF_BOOTSTRAP_OUTPUT)libbpf.a BPFTOOL_VERSION ?= $(shell make -rR --no-print-directory -sC ../../.. kernelversion) -$(LIBBPF_OUTPUT): +$(LIBBPF_OUTPUT) $(BOOTSTRAP_OUTPUT) $(LIBBPF_BOOTSTRAP_OUTPUT): $(QUIET_MKDIR)mkdir -p $@ $(LIBBPF): FORCE | $(LIBBPF_OUTPUT) $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) $(LIBBPF_OUTPUT)libbpf.a +$(LIBBPF_BOOTSTRAP): FORCE | $(LIBBPF_BOOTSTRAP_OUTPUT) + $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_BOOTSTRAP_OUTPUT) \ + ARCH= CC=$(HOSTCC) LD=$(HOSTLD) $@ + $(LIBBPF)-clean: $(LIBBPF_OUTPUT) $(call QUIET_CLEAN, libbpf) $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_OUTPUT) clean >/dev/null +$(LIBBPF_BOOTSTRAP)-clean: $(LIBBPF_BOOTSTRAP_OUTPUT) + $(call QUIET_CLEAN, libbpf-bootstrap) + $(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(LIBBPF_BOOTSTRAP_OUTPUT) clean >/dev/null + prefix ?= /usr/local bash_compdir ?= /usr/share/bash-completion/completions @@ -94,6 +107,7 @@ CFLAGS += -DCOMPAT_NEED_REALLOCARRAY endif LIBS = $(LIBBPF) -lelf -lz +LIBS_BOOTSTRAP = $(LIBBPF_BOOTSTRAP) -lelf -lz ifeq ($(feature-libcap), 1) CFLAGS += -DUSE_LIBCAP LIBS += -lcap @@ -120,9 +134,9 @@ CFLAGS += -DHAVE_LIBBFD_SUPPORT SRCS += $(BFD_SRCS) endif -BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstrap) +BPFTOOL_BOOTSTRAP := $(BOOTSTRAP_OUTPUT)bpftool -BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o) +BOOTSTRAP_OBJS = $(addprefix $(BOOTSTRAP_OUTPUT),main.o common.o json_writer.o gen.o btf.o) OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \ @@ -169,12 +183,16 @@ $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c $(OUTPUT)feature.o: | zdep -$(BPFTOOL_BOOTSTRAP): $(BOOTSTRAP_OBJS) $(LIBBPF) - $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(BOOTSTRAP_OBJS) $(LIBS) +$(BPFTOOL_BOOTSTRAP): $(BOOTSTRAP_OBJS) $(LIBBPF_BOOTSTRAP) + $(QUIET_LINK)$(HOSTCC) $(CFLAGS) $(LDFLAGS) -o $@ $(BOOTSTRAP_OBJS) \ + $(LIBS_BOOTSTRAP) $(OUTPUT)bpftool: $(OBJS) $(LIBBPF) $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) $(LIBS) +$(BOOTSTRAP_OUTPUT)%.o: %.c | $(BOOTSTRAP_OUTPUT) + $(QUIET_CC)$(HOSTCC) $(CFLAGS) -c -MMD -o $@ $< + $(OUTPUT)%.o: %.c $(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $< @@ -182,11 +200,11 @@ feature-detect-clean: $(call QUIET_CLEAN, feature-detect) $(Q)$(MAKE) -C $(srctree)/tools/build/feature/ clean >/dev/null -clean: $(LIBBPF)-clean feature-detect-clean +clean: $(LIBBPF)-clean $(LIBBPF_BOOTSTRAP)-clean feature-detect-clean $(call QUIET_CLEAN, bpftool) $(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d - $(Q)$(RM) -- $(BPFTOOL_BOOTSTRAP) $(OUTPUT)*.skel.h $(OUTPUT)vmlinux.h - $(Q)$(RM) -r -- $(OUTPUT)libbpf/ + $(Q)$(RM) -- $(OUTPUT)*.skel.h $(OUTPUT)vmlinux.h + $(Q)$(RM) -r -- $(LIBBPF_OUTPUT) $(BOOTSTRAP_OUTPUT) $(call QUIET_CLEAN, core-gen) $(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool $(Q)$(RM) -r -- $(OUTPUT)feature/