From e4ac80ef8198636a23866a59575917550328886f Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Fri, 12 Nov 2021 15:51:30 +0000 Subject: tools/runqslower: Fix cross-build Commit be79505caf3f ("tools/runqslower: Install libbpf headers when building") uses the target libbpf to build the host bpftool, which doesn't work when cross-building: make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/bpf/runqslower O=/tmp/runqslower ... LINK /tmp/runqslower/bpftool/bpftool /usr/bin/ld: /tmp/runqslower/libbpf/libbpf.a(libbpf-in.o): Relocations in generic ELF (EM: 183) /usr/bin/ld: /tmp/runqslower/libbpf/libbpf.a: error adding symbols: file in wrong format collect2: error: ld returned 1 exit status When cross-building, the target architecture differs from the host. The bpftool used for building runqslower is executed on the host, and thus must use a different libbpf than that used for runqslower itself. Remove the LIBBPF_OUTPUT and LIBBPF_DESTDIR parameters, so the bpftool build makes its own library if necessary. In the selftests, pass the host bpftool, already a prerequisite for the runqslower recipe, as BPFTOOL_OUTPUT. The runqslower Makefile will use the bpftool that's already built for selftests instead of making a new one. Fixes: be79505caf3f ("tools/runqslower: Install libbpf headers when building") Signed-off-by: Jean-Philippe Brucker Signed-off-by: Daniel Borkmann Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20211112155128.565680-1-jean-philippe@linaro.org Signed-off-by: Alexei Starovoitov --- tools/bpf/runqslower/Makefile | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'tools/bpf/runqslower/Makefile') diff --git a/tools/bpf/runqslower/Makefile b/tools/bpf/runqslower/Makefile index bbd1150578f7..8791d0e2762b 100644 --- a/tools/bpf/runqslower/Makefile +++ b/tools/bpf/runqslower/Makefile @@ -88,5 +88,4 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(BPFOBJ_OU $(DEFAULT_BPFTOOL): $(BPFOBJ) | $(BPFTOOL_OUTPUT) $(Q)$(MAKE) $(submake_extras) -C ../bpftool OUTPUT=$(BPFTOOL_OUTPUT) \ - LIBBPF_OUTPUT=$(BPFOBJ_OUTPUT) \ - LIBBPF_DESTDIR=$(BPF_DESTDIR) CC=$(HOSTCC) LD=$(HOSTLD) + CC=$(HOSTCC) LD=$(HOSTLD) -- cgit v1.2.3