selftests: net: Add cross-compilation support for BPF programs

The selftests/net does not have proper cross-compilation support, and
does not properly state libbpf as a dependency. Mimic/copy the BPF
build from selftests/bpf, which has the nice side-effect that libbpf
is built as well.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Anders Roxell <anders.roxell@linaro.org>
Link: https://lore.kernel.org/r/20221119171841.2014936-1-bjorn@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Björn Töpel 2022-11-19 18:18:41 +01:00 committed by Paolo Abeni
parent 6dcd6d0152
commit 837a3d66d6

View File

@ -1,14 +1,51 @@
# SPDX-License-Identifier: GPL-2.0
CLANG ?= clang
SCRATCH_DIR := $(OUTPUT)/tools
BUILD_DIR := $(SCRATCH_DIR)/build
BPFDIR := $(abspath ../../../lib/bpf)
APIDIR := $(abspath ../../../include/uapi)
CCINCLUDE += -I../../bpf
CCINCLUDE += -I../../../../lib
CCINCLUDE += -I../../../../../usr/include/
CCINCLUDE += -I$(SCRATCH_DIR)/include
BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a
MAKE_DIRS := $(BUILD_DIR)/libbpf
$(MAKE_DIRS):
mkdir -p $@
TEST_CUSTOM_PROGS = $(OUTPUT)/bpf/nat6to4.o
all: $(TEST_CUSTOM_PROGS)
$(OUTPUT)/%.o: %.c
$(CLANG) -O2 -target bpf -c $< $(CCINCLUDE) -o $@
# Get Clang's default includes on this system, as opposed to those seen by
# '-target bpf'. This fixes "missing" files on some architectures/distros,
# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
#
# Use '-idirafter': Don't interfere with include mechanics except where the
# build would have failed anyways.
define get_sys_includes
$(shell $(1) $(2) -v -E - </dev/null 2>&1 \
| sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
endef
ifneq ($(CROSS_COMPILE),)
CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
endif
CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
$(TEST_CUSTOM_PROGS): $(BPFOBJ)
$(CLANG) -O2 -target bpf -c $(@:.o=.c) $(CCINCLUDE) $(CLANG_SYS_INCLUDES) -o $@
$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \
$(APIDIR)/linux/bpf.h \
| $(BUILD_DIR)/libbpf
$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \
EXTRA_CFLAGS='-g -O0' \
DESTDIR=$(SCRATCH_DIR) prefix= all install_headers
EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR)
EXTRA_CLEAN := $(TEST_CUSTOM_PROGS)