test_kmods/Makefile always pointed KDIR at the kernel source tree root, ignoring O= and KBUILD_OUTPUT. On distro kernels where the source tree has not been built, there was no fallback and the build would fail unconditionally.
When O= or KBUILD_OUTPUT points at a prepared kernel build directory (one containing Module.symvers), pass it through so kbuild can locate the correct build infrastructure. Note that module artifacts still land in the M= directory (test_kmods/); O= only controls where kbuild finds its build infrastructure. Fall back to /lib/modules/$(uname -r)/build when neither an explicit valid build directory nor an in-tree Module.symvers is present. A selftests-only O= value (one that does not contain Module.symvers) is intentionally not treated as a kernel build directory to avoid passing an unrelated directory to kbuild. The parent bpf/Makefile resolves O= and KBUILD_OUTPUT to absolute paths before invoking the test_kmods sub-make so relative paths anchor to the user's invocation directory rather than the sub-make's CWD. Guard the clean target against a missing KDIR unconditionally. In permissive mode, also guard the all target and make the parent Makefile's cp step conditional so that a missing or unbuilt module does not abort the build. Signed-off-by: Ricardo B. Marlière <[email protected]> --- tools/testing/selftests/bpf/Makefile | 10 +++++---- tools/testing/selftests/bpf/test_kmods/Makefile | 30 ++++++++++++++++++++++--- 2 files changed, 33 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 6094fe99b5f6..cc6ee7a2df93 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -296,13 +296,15 @@ $(OUTPUT)/sign-file: ../../../../scripts/sign-file.c # subst() turns the rule into a pattern matching rule $(addprefix test_kmods/,$(subst .ko,%ko,$(TEST_KMODS))): $(VMLINUX_BTF) $(RESOLVE_BTFIDS) $(wildcard test_kmods/Makefile test_kmods/*.[ch]) $(Q)$(RM) test_kmods/*.ko test_kmods/*.mod.o # force re-compilation - $(Q)$(MAKE) $(submake_extras) -C test_kmods \ - RESOLVE_BTFIDS=$(RESOLVE_BTFIDS) \ + $(Q)$(MAKE) $(submake_extras) -C test_kmods \ + $(if $(O),O=$(abspath $(O))) \ + $(if $(KBUILD_OUTPUT),KBUILD_OUTPUT=$(abspath $(KBUILD_OUTPUT)))\ + RESOLVE_BTFIDS=$(RESOLVE_BTFIDS) \ EXTRA_CFLAGS='' EXTRA_LDFLAGS='' $(TEST_KMOD_TARGETS): $(addprefix test_kmods/,$(TEST_KMODS)) $(call msg,MOD,,$@) - $(Q)cp test_kmods/$(@F) $@ + $(Q)$(if $(PERMISSIVE),if [ -f test_kmods/$(@F) ]; then )cp test_kmods/$(@F) $@$(if $(PERMISSIVE),; fi) DEFAULT_BPFTOOL := $(HOST_SCRATCH_DIR)/sbin/bpftool @@ -718,7 +720,7 @@ $(TRUNNER_LIB_OBJS): $(TRUNNER_OUTPUT)/%.o:$(TOOLSDIR)/lib/%.c $(TRUNNER_BINARY)-extras: $(TRUNNER_EXTRA_FILES) | $(TRUNNER_OUTPUT) ifneq ($2:$(OUTPUT),:$(shell pwd)) $$(call msg,EXT-COPY,$(TRUNNER_BINARY),$(TRUNNER_EXTRA_FILES)) - $(Q)rsync -aq $$^ $(TRUNNER_OUTPUT)/ + $(Q)rsync -aq $(if $(PERMISSIVE),--ignore-missing-args) $$^ $(TRUNNER_OUTPUT)/ endif # some X.test.o files have runtime dependencies on Y.bpf.o files diff --git a/tools/testing/selftests/bpf/test_kmods/Makefile b/tools/testing/selftests/bpf/test_kmods/Makefile index 63c4d3f6a12f..dcba595b4b99 100644 --- a/tools/testing/selftests/bpf/test_kmods/Makefile +++ b/tools/testing/selftests/bpf/test_kmods/Makefile @@ -1,5 +1,16 @@ TEST_KMOD_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST))))) -KDIR ?= $(abspath $(TEST_KMOD_DIR)/../../../../..) +SRCTREE_KDIR := $(abspath $(TEST_KMOD_DIR)/../../../../..) +# Honor O=/KBUILD_OUTPUT only if they point at a prepared kernel build +# directory (one containing Module.symvers); otherwise treat the value as a +# selftests-only output directory and fall back to in-tree or distro headers. +# The parent bpf/Makefile resolves O=/KBUILD_OUTPUT to absolute paths before +# invoking this sub-make so relative paths still anchor to the user's +# invocation directory. +KMOD_O := $(or $(O),$(KBUILD_OUTPUT)) +KMOD_O_VALID := $(if $(KMOD_O),$(if $(wildcard $(KMOD_O)/Module.symvers),$(KMOD_O))) +KDIR ?= $(if $(KMOD_O_VALID),$(SRCTREE_KDIR), \ + $(if $(wildcard $(SRCTREE_KDIR)/Module.symvers),$(SRCTREE_KDIR), \ + /lib/modules/$(shell uname -r)/build)) ifeq ($(V),1) Q = @@ -14,8 +25,21 @@ $(foreach m,$(MODULES),$(eval obj-m += $(m:.ko=.o))) CFLAGS_bpf_testmod.o = -I$(src) +# When BPF_STRICT_BUILD != 0, a missing KDIR is fatal (the default). +# When permissive, skip silently. +PERMISSIVE := $(filter 0,$(BPF_STRICT_BUILD)) + all: - $(Q)$(MAKE) -C $(KDIR) M=$(TEST_KMOD_DIR) modules +ifeq ($(PERMISSIVE),) + $(Q)$(MAKE) -C $(KDIR) $(if $(KMOD_O_VALID),O=$(KMOD_O_VALID),KBUILD_OUTPUT=) \ + M=$(TEST_KMOD_DIR) modules +else ifneq ("$(wildcard $(KDIR))", "") + $(Q)$(MAKE) -C $(KDIR) $(if $(KMOD_O_VALID),O=$(KMOD_O_VALID),KBUILD_OUTPUT=) \ + M=$(TEST_KMOD_DIR) modules +endif clean: - $(Q)$(MAKE) -C $(KDIR) M=$(TEST_KMOD_DIR) clean +ifneq ("$(wildcard $(KDIR))", "") + $(Q)$(MAKE) -C $(KDIR) $(if $(KMOD_O_VALID),O=$(KMOD_O_VALID),KBUILD_OUTPUT=) \ + M=$(TEST_KMOD_DIR) clean +endif -- 2.54.0
