2023-02-10 09:43 UTC+0100 ~ Björn Töpel bjorn@kernel.org
From: Björn Töpel bjorn@rivosinc.com
When the BPF selftests are cross-compiled, only the a host version of bpftool is built. This version of bpftool is used to generate various intermediates, e.g., skeletons.
The test runners are also using bpftool. The Makefile will symlink bpftool from the selftest/bpf root, where the test runners will look for the tool:
| ... | $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ | $(OUTPUT)/$(if $2,$2/)bpftool
There are two issues for cross-compilation builds:
- There is no native (cross-compilation target) build of bpftool
- The bootstrap variant of bpftool is never cross-compiled (by design)
Make sure that a native/cross-compiled version of bpftool is built, and if CROSS_COMPILE is set, symlink to the native/non-bootstrap version.
Signed-off-by: Björn Töpel bjorn@rivosinc.com
tools/testing/selftests/bpf/Makefile | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index b2eb3201b85a..b706750f71e2 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -157,8 +157,9 @@ $(notdir $(TEST_GEN_PROGS) \ $(TEST_CUSTOM_PROGS)): %: $(OUTPUT)/% ; # sort removes libbpf duplicates when not cross-building -MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \
$(HOST_BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/resolve_btfids \+MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \
$(BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/bpftool \$(HOST_BUILD_DIR)/resolve_btfids \ $(RUNQSLOWER_OUTPUT) $(INCLUDE_DIR))$(MAKE_DIRS): $(call msg,MKDIR,,$@) @@ -208,6 +209,14 @@ $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_tes $(Q)cp bpf_testmod/bpf_testmod.ko $@ DEFAULT_BPFTOOL := $(HOST_SCRATCH_DIR)/sbin/bpftool +ifneq ($(CROSS_COMPILE),) +CROSS_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool +TRUNNER_BPFTOOL := $(CROSS_BPFTOOL) +USE_BOOTSTRAP := "" +else +TRUNNER_BPFTOOL := $(DEFAULT_BPFTOOL) +USE_BOOTSTRAP := "bootstrap" +endif $(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(RUNQSLOWER_OUTPUT) $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \ @@ -255,6 +264,18 @@ $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ LIBBPF_DESTDIR=$(HOST_SCRATCH_DIR)/ \ prefix= DESTDIR=$(HOST_SCRATCH_DIR)/ install-bin +ifneq ($(CROSS_COMPILE),) +$(CROSS_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \
$(BPFOBJ) | $(BUILD_DIR)/bpftool- $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \
ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) \EXTRA_CFLAGS='-g -O0' \OUTPUT=$(BUILD_DIR)/bpftool/ \LIBBPF_OUTPUT=$(BUILD_DIR)/libbpf/ \LIBBPF_DESTDIR=$(SCRATCH_DIR)/ \prefix= DESTDIR=$(SCRATCH_DIR)/ install-bin+endif
all: docs docs: @@ -518,11 +539,12 @@ endif $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \ $(TRUNNER_EXTRA_OBJS) $$(BPFOBJ) \ $(RESOLVE_BTFIDS) \
$(TRUNNER_BPFTOOL) \ | $(TRUNNER_BINARY)-extras
- $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \
- $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/$(USE_BOOTSTRAP)/bpftool \
Nit: You'll have a double slash in this path when USE_BOOSTRAP is empty (.../tools/build/bpftool//bpftool), but it probably doesn't matter much.
$(OUTPUT)/$(if $2,$2/)bpftoolendef
base-commit: 06744f24696e1e7598412c3df61a538b57ebec22
The changes look good to me, thanks!
Acked-by: Quentin Monnet quentin@isovalent.com
Jean-Philippe, I know you do some cross-compiling with bpftool, how does this look from your side?