Thanks, Oak > -----Original Message----- > From: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> > Sent: July 13, 2022 2:21 PM > To: Zeng, Oak <oak.zeng@xxxxxxxxx> > Cc: bpf@xxxxxxxxxxxxxxx > Subject: Re: Build error of samples/bpf > > On Tue, 12 Jul 2022 at 16:10, Zeng, Oak <oak.zeng@xxxxxxxxx> wrote: > > > > Hello all, > > > > I tried to build the latest samples/bpf following instructions in the > README.rst in samples/bpf folder. I ran into various issue such as: > > > > samples/bpf/Makefile:375: *** Cannot find a vmlinux for VMLINUX_BTF at > any of " /home/szeng/dii-tools/linux/vmlinux", build the kernel or set > VMLINUX_BTF or VMLINUX_H variable > > > > I was able to fix above issue by enable CONFIG_DEBUG_INFO_BTF in > kernel .config file. > > > > But I eventually ran into other errors. I had to fix those errors by install > dwarves, updating my clang/llvm to version 10. > > > > I was able to build it if I comment out all the xdp programs from Makefile. It > seems those xdp programs require advanced features such as data structure > layout in vmlinux.h (dumped from vmlinux using bpftool) and this require > special kernel config support. > > > > So I thought instead of fixing those errors one by one, I should ask those > who are working in this area, is there any instructions on how to build > samples/bpf? The README.rst seems out-of-date, for example, it doesn't > mention CONFIG_DEBUG_INFO_BTF. The required llvm/clang version in > README.rst is also out-of-date. > > > > More specifically, to build samples/bpf, is there an example kernel .config > to use? I tried those config here > https://github.com/torvalds/linux/blob/master/tools/testing/selftests/bpf/c > onfig but build errors persist. > > > > Or is there any other tools I need to install/update on my system? > > > > My whole build log is as below: > > > > szeng@linux:~/dii-tools/linux$ make M=samples/bpf > > readelf: Error: Missing knowledge of 32-bit reloc types used in DWARF > sections of machine number 247 > > readelf: Warning: unable to apply unsupported reloc type 10 to > section .debug_info > > readelf: Warning: unable to apply unsupported reloc type 1 to > section .debug_info > > readelf: Warning: unable to apply unsupported reloc type 10 to > section .debug_info make -C /home/szeng/dii- > tools/linux/samples/bpf/../../tools/lib/bpf RM='rm -rf' EXTRA_CFLAGS="- > Wall -O2 -Wmissing-prototypes -Wstrict-prototypes -I./usr/include - > I./tools/testing/selftests/bpf/ -I/home/szeng/dii- > tools/linux/samples/bpf/libbpf/include -I./tools/include -I./tools/perf - > DHAVE_ATTR_TEST=0" \ > > LDFLAGS= srctree=/home/szeng/dii-tools/linux/samples/bpf/../../ \ > > O= OUTPUT=/home/szeng/dii-tools/linux/samples/bpf/libbpf/ > DESTDIR=/home/szeng/dii-tools/linux/samples/bpf/libbpf prefix= \ > > /home/szeng/dii-tools/linux/samples/bpf/libbpf/libbpf.a > install_headers > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/libbpf.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/bpf.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/nlattr.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/btf.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/libbpf_errno.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/str_error.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/netlink.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/bpf_prog_linfo.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/libbpf_probes.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/xsk.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/hashmap.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/btf_dump.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/ringbuf.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/strset.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/linker.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/gen_loader.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/relo_core.o > > LD /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/libbpf- > in.o > > LINK /home/szeng/dii-tools/linux/samples/bpf/libbpf/libbpf.a > > INSTALL headers > > CC samples/bpf/test_lru_dist > > CC samples/bpf/sock_example > > CC samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.o > > CC samples/bpf/../../tools/testing/selftests/bpf/trace_helpers.o > > CC samples/bpf/cookie_uid_helper_example.o > > CC samples/bpf/cpustat_user.o > > CC samples/bpf/fds_example.o > > CC samples/bpf/hbm.o > > CC samples/bpf/i915_latency_hist_user.o > > CC samples/bpf/i915_stat_user.o > > CC samples/bpf/ibumad_user.o > > CC samples/bpf/lathist_user.o > > CC samples/bpf/lwt_len_hist_user.o > > CC samples/bpf/map_perf_test_user.o > > CC samples/bpf/offwaketime_user.o > > CC samples/bpf/sampleip_user.o > > CC samples/bpf/sockex1_user.o > > CC samples/bpf/sockex2_user.o > > CC samples/bpf/sockex3_user.o > > CC samples/bpf/spintest_user.o > > CC samples/bpf/syscall_tp_user.o > > CC samples/bpf/task_fd_query_user.o > > CC samples/bpf/tc_l2_redirect_user.o > > CC samples/bpf/test_cgrp2_array_pin.o > > CC samples/bpf/test_cgrp2_attach.o > > CC samples/bpf/test_cgrp2_sock.o > > CC samples/bpf/test_cgrp2_sock2.o > > CC samples/bpf/test_current_task_under_cgroup_user.o > > CC samples/bpf/test_map_in_map_user.o > > CC samples/bpf/test_overhead_user.o > > CC samples/bpf/test_probe_write_user_user.o > > CC samples/bpf/trace_event_user.o > > CC samples/bpf/trace_output_user.o > > CC samples/bpf/tracex1_user.o > > CC samples/bpf/tracex2_user.o > > CC samples/bpf/tracex3_user.o > > CC samples/bpf/tracex4_user.o > > CC samples/bpf/tracex5_user.o > > CC samples/bpf/tracex6_user.o > > CC samples/bpf/tracex7_user.o > > CC samples/bpf/xdp1_user.o > > CC samples/bpf/xdp_adjust_tail_user.o > > CC samples/bpf/xdp_fwd_user.o > > make -C /home/szeng/dii-tools/linux/samples/bpf/../../tools/bpf/bpftool > srctree=/home/szeng/dii-tools/linux/samples/bpf/../../ \ > > OUTPUT=/home/szeng/dii-tools/linux/samples/bpf/bpftool/ \ > > LIBBPF_OUTPUT=/home/szeng/dii-tools/linux/samples/bpf/libbpf/ \ > > LIBBPF_DESTDIR=/home/szeng/dii-tools/linux/samples/bpf/libbpf/ > > > > Auto-detecting system features: > > ... libbfd: [ OFF ] > > ... disassembler-four-args: [ OFF ] > > ... zlib: [ on ] > > ... libcap: [ OFF ] > > ... clang-bpf-co-re: [ on ] > > > > > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/libbpf.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/bpf.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/nlattr.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/btf.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/libbpf_errno.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/str_error.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/netlink.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/bpf_prog_linfo.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/libbpf_probes.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/xsk.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/hashmap.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/btf_dump.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/ringbuf.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/strset.o > > CC /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/linker.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/gen_loader.o > > CC /home/szeng/dii- > tools/linux/samples/bpf/libbpf/staticobjs/relo_core.o > > LD /home/szeng/dii-tools/linux/samples/bpf/libbpf/staticobjs/libbpf- > in.o > > LINK /home/szeng/dii-tools/linux/samples/bpf/libbpf/libbpf.a > > CLANG /home/szeng/dii-tools/linux/samples/bpf/bpftool/profiler.bpf.o > > GEN /home/szeng/dii-tools/linux/samples/bpf/bpftool/profiler.skel.h > > CC /home/szeng/dii-tools/linux/samples/bpf/bpftool/prog.o > > CLANG /home/szeng/dii-tools/linux/samples/bpf/bpftool/pid_iter.bpf.o > > GEN /home/szeng/dii-tools/linux/samples/bpf/bpftool/pid_iter.skel.h > > CC /home/szeng/dii-tools/linux/samples/bpf/bpftool/pids.o > > LINK /home/szeng/dii-tools/linux/samples/bpf/bpftool/bpftool > > CC samples/bpf/xdp_router_ipv4_user.o > > CC samples/bpf/xdp_rxq_info_user.o > > CC samples/bpf/xdp_sample_pkts_user.o > > CC samples/bpf/xdp_tx_iptunnel_user.o > > CC samples/bpf/xdpsock_ctrl_proc.o > > CC samples/bpf/xsk_fwd.o > > CLANG-BPF samples/bpf/xdp_sample.bpf.o > > CLANG-BPF samples/bpf/xdp_redirect_map_multi.bpf.o > > CLANG-BPF samples/bpf/xdp_redirect_cpu.bpf.o > > CLANG-BPF samples/bpf/xdp_redirect_map.bpf.o > > CLANG-BPF samples/bpf/xdp_monitor.bpf.o > > CLANG-BPF samples/bpf/xdp_redirect.bpf.o > > BPF GEN-OBJ samples/bpf/xdp_monitor > > BPF GEN-SKEL samples/bpf/xdp_monitor > > libbpf: map 'rx_cnt': unexpected def kind var. > > IIRC, this error is due to older clang. Can you try with a newer clang > (11 and above)? Thank you Kumar. I updated to llvm/clang to version 12, the issue persists. I also have another problem... To build those xdp samples, I need to enable CONFIG_DEBUG_INFO_BTF. But once this is enabled, I failed to build linux kernel with below errors. I was able to build on a 4.15 ubuntu machine but on a 5.11 ubuntu machine, I had below error to build the same kernel. Any one can give me some hint? I searched google but didn't figure out. I noticed somethings is killed during build of .bpf.vmlinux.bin.o, so I guess some of my tools is not updated? szeng@szeng-develop:~/dii-tools/linux$ make -j$(nproc) DESCEND objtool DESCEND bpf/resolve_btfids CALL scripts/atomic/check-atomics.sh CALL scripts/checksyscalls.sh CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a CHK kernel/kheaders_data.tar.xz GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o MODPOST vmlinux.symvers MODINFO modules.builtin.modinfo GEN modules.builtin LD .tmp_vmlinux.btf BTF .btf.vmlinux.bin.o Killed LD .tmp_vmlinux.kallsyms1 KSYMS .tmp_vmlinux.kallsyms1.S AS .tmp_vmlinux.kallsyms1.S LD .tmp_vmlinux.kallsyms2 KSYMS .tmp_vmlinux.kallsyms2.S AS .tmp_vmlinux.kallsyms2.S LD vmlinux BTFIDS vmlinux FAILED: load BTF from vmlinux: No such file or directory make: *** [Makefile:1183: vmlinux] Error 255 make: *** Deleting file 'vmlinux' Thanks, Oak > > > Error: failed to open BPF object file: Invalid argument > > samples/bpf/Makefile:430: recipe for target > 'samples/bpf/xdp_monitor.skel.h' failed > > make[1]: *** [samples/bpf/xdp_monitor.skel.h] Error 255 > > make[1]: *** Deleting file 'samples/bpf/xdp_monitor.skel.h' > > Makefile:1868: recipe for target 'samples/bpf' failed > > make: *** [samples/bpf] Error 2 > > > > > > Thanks, > > Oak > >
