On Wed, Jan 04, 2023 at 10:19:37AM -0800, Stanislav Fomichev wrote: > On Wed, Jan 4, 2023 at 10:14 AM David Vernet <void@xxxxxxxxxxxxx> wrote: > > > > On Wed, Jan 04, 2023 at 01:17:40PM +0100, Magnus Karlsson wrote: > > > From: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> > > > > > > Get rid of the built-in XDP program that was part of the old libbpf > > > code in xsk.c and replace it with an eBPF program build using the > > > framework by all the other bpf selftests. This will form the base for > > > adding more programs in later commits. > > > > > > Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> > > > --- > > > tools/testing/selftests/bpf/Makefile | 2 +- > > > .../selftests/bpf/progs/xsk_xdp_progs.c | 19 ++++ > > > tools/testing/selftests/bpf/xsk.c | 88 ++++--------------- > > > tools/testing/selftests/bpf/xsk.h | 6 +- > > > tools/testing/selftests/bpf/xskxceiver.c | 72 ++++++++------- > > > tools/testing/selftests/bpf/xskxceiver.h | 7 +- > > > 6 files changed, 88 insertions(+), 106 deletions(-) > > > create mode 100644 tools/testing/selftests/bpf/progs/xsk_xdp_progs.c > > > > > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > > > index 205e8c3c346a..a0193a8f9da6 100644 > > > --- a/tools/testing/selftests/bpf/Makefile > > > +++ b/tools/testing/selftests/bpf/Makefile > > > @@ -240,7 +240,7 @@ $(OUTPUT)/flow_dissector_load: $(TESTING_HELPERS) > > > $(OUTPUT)/test_maps: $(TESTING_HELPERS) > > > $(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS) > > > $(OUTPUT)/xsk.o: $(BPFOBJ) > > > -$(OUTPUT)/xskxceiver: $(OUTPUT)/xsk.o > > > +$(OUTPUT)/xskxceiver: $(OUTPUT)/xsk.o $(OUTPUT)/xsk_xdp_progs.skel.h > > > > Hi Magnus, > > > > This seems to break the selftests build for clang: > > > > $ pwd > > <redacted>/bpf-next/tools/testing/selftests/bpf > > > > $ make LLVM=1 CC=clang > > MKDIR libbpf > > HOSTCC /home/void/upstream/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/fixdep.o > > HOSTLD /home/void/upstream/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/fixdep-in.o > > LINK /home/void/upstream/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/fixdep > > > > ... > > > > GEN-SKEL [test_progs-no_alu32] test_static_linked.skel.h > > LINK-BPF [test_progs-no_alu32] test_usdt.bpf.o > > GEN-SKEL [test_progs-no_alu32] linked_vars.skel.h > > GEN-SKEL [test_progs-no_alu32] linked_funcs.skel.h > > EXT-COPY [test_progs-no_alu32] urandom_read bpf_testmod.ko liburandom_read.so xdp_synproxy sign-file ima_setup.sh verify_sig_setup.sh btf_dump_test_case_bitfields.c btf_dump_test_case_multidim.c btf_dump_test_case_namespacing.c btf_dump_test_case_ordering.c btf_dump_test_case_packing.c btf_dump_test_case_padding.c btf_dump_test_case_syntax.c > > GEN-SKEL [test_progs-no_alu32] linked_maps.skel.h > > GEN-SKEL [test_progs-no_alu32] test_subskeleton.skel.h > > BINARY xskxceiver > > BINARY bench > > GEN-SKEL [test_progs-no_alu32] test_subskeleton_lib.skel.h > > GEN-SKEL [test_progs-no_alu32] test_usdt.skel.h > > clang-15: error: cannot specify -o when generating multiple output files > > make: *** [Makefile:171: /home/void/upstream/bpf-next/tools/testing/selftests/bpf/xskxceiver] Error 1 > > make: *** Waiting for unfinished jobs.... > > make[1]: Nothing to be done for 'docs'. > > $ > > > > It's also broken on CI: https://github.com/kernel-patches/bpf/actions/runs/3837984934/jobs/6533917001 > > > > Could you please look into this? > > Ugh, that's the same issue I'm getting for my xdp_hw_metadata binary. > And I'm still at loss on how to reproduce it locally. (I've tried 'apt > install clang-16 in ubuntu latest docker container' and it's still > fine). I was able to reproduce this issue locally: [void@maniforge bpf]$ make -j LLVM=1 CC=clang GEN-SKEL [test_progs] pyperf600.skel.h GEN-SKEL [test_progs] test_verif_scale2.skel.h LINK-BPF [test_progs] test_static_linked.bpf.o LINK-BPF [test_progs] linked_funcs.bpf.o ... LINK-BPF [test_progs-no_alu32] test_usdt.bpf.o EXT-COPY [test_progs-no_alu32] urandom_read bpf_testmod.ko liburandom_read.so xdp_synproxy sign-file ima_setup.sh verify_sig_setup.sh btf_dump_test_case_bitfields.c btf_dump_test_case_multidim.c btf_dump_test_case_namespacing.c btf_dump_test_case_ordering.c btf_dump_test_case_packing.c btf_dump_test_case_padding.c btf_dump_test_case_syntax.c GEN-SKEL [test_progs-no_alu32] linked_funcs.skel.h BINARY bench GEN-SKEL [test_progs-no_alu32] test_subskeleton.skel.h BINARY xdp_hw_metadata GEN-SKEL [test_progs-no_alu32] test_subskeleton_lib.skel.h GEN-SKEL [test_progs-no_alu32] test_usdt.skel.h clang-15: error: cannot specify -o when generating multiple output files make: *** [Makefile:171: /home/void/upstream/bpf-next/tools/testing/selftests/bpf/xdp_hw_metadata] Error 1 make: *** Waiting for unfinished jobs.... make[1]: Nothing to be done for 'docs'. Here's the actual clang command being executed: [void@maniforge bpf]$ make LLVM=1 --dry-run xdp_hw_metadata printf ' %-8s%s %s%s\n' "BINARY" "" "xdp_hw_metadata" ""; clang --target=x86_64-linux-gnu -fintegrated-as -g -O0 -rdynamic -Wall -Werror -DHAVE_GENHDR -I/home/void/upstream/bpf-next/tools/testing/selftests/bpf -I/home/void/upstream/bpf-next/tools/testing/selftests/bpf/tools/include -I/home/void/upstream/bpf-next/include/generated -I/home/void/upstream/bpf-next/tools/lib -I/home/void/upstream/bpf-next/tools/include -I/home/void/upstream/bpf-next/tools/include/uapi -I/home/void/upstream/bpf-next/tools/testing/selftests/bpf -Wno-unused-command-line-argument -static xdp_hw_metadata.c /home/void/upstream/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.a /home/void/upstream/bpf-next/tools/testing/selftests/bpf/xsk.o /home/void/upstream/bpf-next/tools/testing/selftests/bpf/xdp_hw_metadata.skel.h /home/void/upstream/bpf-next/tools/testing/selftests/bpf/network_helpers.o -lelf -lz -lrt -lpthread -o /home/void/upstream/bpf-next/tools/testing/selftests/bpf/xdp_hw_metadata and the output using --debug=j [void@maniforge bpf]$ make LLVM=1 --debug=j xdp_hw_metadata Putting child 0x55cc78cd6670 (/home/void/upstream/bpf-next/tools/testing/selftests/bpf/xdp_hw_metadata) PID 693804 on the chain. Live child 0x55cc78cd6670 (/home/void/upstream/bpf-next/tools/testing/selftests/bpf/xdp_hw_metadata) PID 693804 BINARY xdp_hw_metadata Reaping winning child 0x55cc78cd6670 PID 693804 Live child 0x55cc78cd6670 (/home/void/upstream/bpf-next/tools/testing/selftests/bpf/xdp_hw_metadata) PID 693805 clang-15: error: cannot specify -o when generating multiple output files Reaping losing child 0x55cc78cd6670 PID 693805 make: *** [Makefile:171: /home/void/upstream/bpf-next/tools/testing/selftests/bpf/xdp_hw_metadata] Error 1 Removing child 0x55cc78cd6670 PID 693805 from chain. make is taking the xdp_hw_metadata.skel.h file and providing it as an input to clang. So I believe what's going on here is that the clang command above is actually creating two output files: 1. xdp_hw_metadata 2. The precompiled header generated from xdp_hw_metadata.skel.h and the error is clang reasonably saying: "I don't know which output file you're referring to with -o". I'm surprised that gcc doesn't complain about this, but I assume that it's doing the far more non-intuitive thing of first outputting the precompiled header as xdp_hw_metadata, and then immediately overwriting it with the actual xdp_hw_metadata binary. > Any pointers on how to debug those github actions locally? > > > Thanks, > > David
