On Thu, Feb 9, 2023 at 4:12 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote: > > v1: https://lore.kernel.org/bpf/20230208205642.270567-1-iii@xxxxxxxxxxxxx/ > v1 -> v2: > - Apply runqslower's EXTRA_CFLAGS and EXTRA_LDFLAGS unconditionally. > - Use u64 for uretprobe_byname2_rc. > - Use BPF_UPROBE() instead of PT_REGS_xxx(). > - Use void * instead of char * for pointer arithmetic. > - Rename libbpf_mark_defined() to __libbpf_mark_mem_written(), add > convenience wrappers. > - Add a comment about defined(__has_feature) && > __has_feature(memory_sanitizer). > - Extract is_percpu_bpf_map_type(). > - Introduce bpf_get_{map,prog,link,btf}_info_by_fd() and convert all > code to use them. If it's too early for that, in particular for > samples and perf, the respective patches can be dropped. perf is too early, the rest is fine I applied first 7 patches for now, I'll go review the rest a bit later. > - Unpoison infos returned by these functions, paying attention to > potentially missing fields. Use macros to reduce boilerplate. > - Move capget() unpoisoning to LLVM [5]. > - With that, only a few cases remain where data needs to be > unpoisoned in selftests. > > Hi, > > This series adds support for building selftests with Memory Sanitizer > [1] - a compiler instrumentation for detecting usages of undefined > memory. > > The primary motivation is to make sure that such usages do not occur > during testing, since the ones that have not been caught yet are likely > to affect the CI results on s390x. The secondary motivation is to be > able to use libbpf in applications instrumented with MSan (it requires > all code running in a process to be instrumented). > > MSan has found one real issue (fixed by patch 7), and of course a > number of false positives. This rest of this series deals with > preparing the build infrastructure and adding MSan annotations to > libbpf and selftests. > > The setup I'm using is as follows: > > - Instrumented zlib-ng and patched elfutils [2]. > - Patched LLVM [3, 4, 5]. > - Clang-built kernel. > - Building tests with MSan: > > make \ > -C tools/testing/selftests/bpf \ > CC="ccache clang-17" \ > LD=ld \ > HOSTCC="ccache clang-17" \ > HOSTLD=ld \ > LLVM=1 \ > LLVM_SUFFIX=-17 \ > OBJCOPY=objcopy \ > CLANG="ccache clang-17" \ > LLVM_STRIP=llvm-strip-17 \ > LLC=llc-17 \ > BPF_GCC= \ > SAN_CFLAGS="-fsanitize=memory \ > -fsanitize-memory-track-origins \ > -I$PWD/../zlib-ng/dist/include \ > -I$PWD/../elfutils/dist/include" \ > SAN_LDFLAGS="-fsanitize=memory \ > -fsanitize-memory-track-origins \ > -L$PWD/../zlib-ng/dist/lib \ > -L$PWD/../elfutils/dist/lib" \ > CROSS_COMPILE=s390x-linux-gnu- > > It's a lot of options, but most of them are trivial: setting up LLVM > toolchain, taking in account s390x quirks, setting up MSan and > disabling bpf-gcc. The CROSS_COMPILE one is a hack: instrumenting > bpftool turned out to be too complicated from the build system > perspective, so having CROSS_COMPILE forces compiling the host libbpf > uninstrumented and guest libbpf instrumented. > > - Running tests with MSan on s390x: > > LD_LIBRARY_PATH=<instrumented libs> ./test_progs > ... > Summary: 282/1624 PASSED, 23 SKIPPED, 4 FAILED > > The 4 failures happen without MSan too, they are already known and > denylisted. > > Best regards, > Ilya > > [1] https://clang.llvm.org/docs/MemorySanitizer.html > [2] https://sourceware.org/pipermail/elfutils-devel/2023q1/005831.html > [3] https://reviews.llvm.org/D143296 > [4] https://reviews.llvm.org/D143330 > [5] https://reviews.llvm.org/D143660 > > Ilya Leoshkevich (16): > selftests/bpf: Quote host tools > tools: runqslower: Add EXTRA_CFLAGS and EXTRA_LDFLAGS support > selftests/bpf: Split SAN_CFLAGS and SAN_LDFLAGS > selftests/bpf: Forward SAN_CFLAGS and SAN_LDFLAGS to runqslower and > libbpf > selftests/bpf: Attach to fopen()/fclose() in uprobe_autoattach > selftests/bpf: Attach to fopen()/fclose() in attach_probe > libbpf: Fix alen calculation in libbpf_nla_dump_errormsg() > libbpf: Introduce bpf_{btf,link,map,prog}_get_info_by_fd() > libbpf: Use bpf_{btf,link,map,prog}_get_info_by_fd() > bpftool: Use bpf_{btf,link,map,prog}_get_info_by_fd() > perf: Use bpf_{btf,link,map,prog}_get_info_by_fd() > samples/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd() > selftests/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd() > libbpf: Factor out is_percpu_bpf_map_type() > libbpf: Add MSan annotations > selftests/bpf: Add MSan annotations > > samples/bpf/test_map_in_map_user.c | 2 +- > samples/bpf/xdp1_user.c | 2 +- > samples/bpf/xdp_adjust_tail_user.c | 2 +- > samples/bpf/xdp_fwd_user.c | 4 +- > samples/bpf/xdp_redirect_cpu_user.c | 4 +- > samples/bpf/xdp_rxq_info_user.c | 2 +- > samples/bpf/xdp_sample_pkts_user.c | 2 +- > samples/bpf/xdp_tx_iptunnel_user.c | 2 +- > tools/bpf/bpftool/btf.c | 13 +- > tools/bpf/bpftool/btf_dumper.c | 4 +- > tools/bpf/bpftool/cgroup.c | 4 +- > tools/bpf/bpftool/common.c | 13 +- > tools/bpf/bpftool/link.c | 4 +- > tools/bpf/bpftool/main.h | 3 +- > tools/bpf/bpftool/map.c | 8 +- > tools/bpf/bpftool/prog.c | 24 +-- > tools/bpf/bpftool/struct_ops.c | 6 +- > tools/bpf/runqslower/Makefile | 2 + > tools/lib/bpf/bpf.c | 179 +++++++++++++++++- > tools/lib/bpf/bpf.h | 13 ++ > tools/lib/bpf/btf.c | 9 +- > tools/lib/bpf/libbpf.c | 26 +-- > tools/lib/bpf/libbpf.map | 5 + > tools/lib/bpf/libbpf_internal.h | 46 +++++ > tools/lib/bpf/netlink.c | 2 +- > tools/lib/bpf/nlattr.c | 2 +- > tools/lib/bpf/ringbuf.c | 4 +- > tools/perf/util/bpf-utils.c | 4 +- > tools/perf/util/bpf_counter.c | 2 +- > tools/perf/util/bpf_counter.h | 6 +- > tools/testing/selftests/bpf/Makefile | 17 +- > .../bpf/map_tests/map_in_map_batch_ops.c | 2 +- > .../selftests/bpf/prog_tests/attach_probe.c | 10 +- > .../selftests/bpf/prog_tests/bpf_iter.c | 8 +- > .../selftests/bpf/prog_tests/bpf_obj_id.c | 20 +- > .../selftests/bpf/prog_tests/bpf_tcp_ca.c | 3 + > tools/testing/selftests/bpf/prog_tests/btf.c | 24 +-- > .../selftests/bpf/prog_tests/btf_map_in_map.c | 2 +- > .../selftests/bpf/prog_tests/check_mtu.c | 2 +- > .../selftests/bpf/prog_tests/enable_stats.c | 2 +- > .../selftests/bpf/prog_tests/fexit_bpf2bpf.c | 14 +- > .../bpf/prog_tests/flow_dissector_reattach.c | 10 +- > .../bpf/prog_tests/libbpf_get_fd_by_id_opts.c | 4 +- > .../selftests/bpf/prog_tests/lsm_cgroup.c | 3 +- > .../selftests/bpf/prog_tests/metadata.c | 8 +- > tools/testing/selftests/bpf/prog_tests/mmap.c | 2 +- > .../selftests/bpf/prog_tests/perf_link.c | 2 +- > .../selftests/bpf/prog_tests/pinning.c | 2 +- > .../selftests/bpf/prog_tests/prog_run_opts.c | 2 +- > .../selftests/bpf/prog_tests/recursion.c | 4 +- > .../selftests/bpf/prog_tests/send_signal.c | 2 + > .../selftests/bpf/prog_tests/sockmap_basic.c | 6 +- > .../bpf/prog_tests/task_local_storage.c | 8 +- > .../testing/selftests/bpf/prog_tests/tc_bpf.c | 4 +- > .../bpf/prog_tests/tp_attach_query.c | 9 +- > .../bpf/prog_tests/unpriv_bpf_disabled.c | 8 +- > .../bpf/prog_tests/uprobe_autoattach.c | 14 +- > .../selftests/bpf/prog_tests/verif_stats.c | 5 +- > .../selftests/bpf/prog_tests/xdp_attach.c | 4 +- > .../selftests/bpf/prog_tests/xdp_bonding.c | 3 + > .../bpf/prog_tests/xdp_cpumap_attach.c | 8 +- > .../bpf/prog_tests/xdp_devmap_attach.c | 8 +- > .../selftests/bpf/prog_tests/xdp_info.c | 2 +- > .../selftests/bpf/prog_tests/xdp_link.c | 10 +- > .../selftests/bpf/progs/test_attach_probe.c | 11 +- > .../bpf/progs/test_uprobe_autoattach.c | 16 +- > tools/testing/selftests/bpf/test_maps.c | 2 +- > .../selftests/bpf/test_skb_cgroup_id_user.c | 2 +- > .../bpf/test_tcp_check_syncookie_user.c | 2 +- > tools/testing/selftests/bpf/test_verifier.c | 8 +- > tools/testing/selftests/bpf/testing_helpers.c | 2 +- > tools/testing/selftests/bpf/xdp_synproxy.c | 15 +- > 72 files changed, 478 insertions(+), 211 deletions(-) > > -- > 2.39.1 >
