From: Andrii Nakryiko andriin@fb.com
[ Upstream commit 6bcaf41f9613278cd5897fc80ab93033bda8efaa ]
runqslower's Makefile is building/installing bpftool into $(OUTPUT)/sbin/bpftool, which coincides with $(DEFAULT_BPFTOOL). In practice this means that often when building selftests from scratch (after `make clean`), selftests are racing with runqslower to simultaneously build bpftool and one of the two processes fail due to file being busy. Prevent this race by explicitly order-depending on $(BPFTOOL_DEFAULT).
Fixes: a2c9652f751e ("selftests: Refactor build to remove tools/lib/bpf from include path") Signed-off-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: John Fastabend john.fastabend@gmail.com Link: https://lore.kernel.org/bpf/20200805004757.2960750-1-andriin@fb.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/bpf/Makefile | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 22aaec74ea0ab..dab182ffec320 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -141,7 +141,9 @@ VMLINUX_BTF_PATHS := $(if $(O),$(O)/vmlinux) \ /boot/vmlinux-$(shell uname -r) VMLINUX_BTF := $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
-$(OUTPUT)/runqslower: $(BPFOBJ) +DEFAULT_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool + +$(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \ OUTPUT=$(SCRATCH_DIR)/ VMLINUX_BTF=$(VMLINUX_BTF) \ BPFOBJ=$(BPFOBJ) BPF_INCLUDE=$(INCLUDE_DIR) && \ @@ -163,7 +165,6 @@ $(OUTPUT)/test_netcnt: cgroup_helpers.c $(OUTPUT)/test_sock_fields: cgroup_helpers.c $(OUTPUT)/test_sysctl: cgroup_helpers.c
-DEFAULT_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool BPFTOOL ?= $(DEFAULT_BPFTOOL) $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ $(BPFOBJ) | $(BUILD_DIR)/bpftool