On Fri, Feb 2, 2024 at 8:34 AM Anton Protopopov <aspsk@xxxxxxxxxxxxx> wrote: > > This series adds support for mapping between xlated and original > instructions offsets, mapping between xlated and jitted instructions > offsets (x86), support for two new BPF instruction JA[SRC=1] > (goto[l]_or_nop) and JA[SRC=3] (nop_or_goto[l]), and a new syscall to > configure the jitted values of such instructions. > > This a follow up to the previous attempt to add static keys support > (see [1], [2]) which implements lower-level functionality than what > was proposed before. > > The first patch . > The second patch adds xlated -> original mapping. > The third patch adds . > > The fourth patch adds support for new instructions. > And the fifth patch adds support for new syscall. > > The following patches are included: > Patch 1 is a formal bug fix > Patch 2 adds the xlated -> original mapping > Patch 3 adds the xlated -> jitted mapping > Patch 4 adds tests for instructions mappings > Patch 5 adds bpftool support for printing new instructions > Patch 6 add support for an extended JA instruction > Patch 7 add support for kernel/bpftool to display new instructions > Patch 8 adds a new BPF_STATIC_BRANCH_UPDATE syscall > Patch 9 adds tests for the new ja* instructions and the new syscall > > Altogether this provides enough functionality to dynamically patch > programs and support simple static keys. > > rfc -> v1: > - converted to v1 based on the feedback (there was none) > - bpftool support was added to dump new instructions > - self-tests were added > - minor fixes & checkpatch warnings > > [1] https://lpc.events/event/17/contributions/1608/attachments/1278/2578/bpf-static-keys.pdf > [2] https://lore.kernel.org/bpf/20231206141030.1478753-1-aspsk@xxxxxxxxxxxxx/ > [3] https://github.com/llvm/llvm-project/pull/75110 > > Anton Protopopov (9): > bpf: fix potential error return > bpf: keep track of and expose xlated insn offsets > bpf: expose how xlated insns map to jitted insns > selftests/bpf: Add tests for instructions mappings > bpftool: dump new fields of bpf prog info > bpf: add support for an extended JA instruction > bpf: Add kernel/bpftool asm support for new instructions > bpf: add BPF_STATIC_BRANCH_UPDATE syscall > selftests/bpf: Add tests for new ja* instructions > > arch/x86/net/bpf_jit_comp.c | 73 ++++- > include/linux/bpf.h | 11 + > include/linux/bpf_verifier.h | 1 - > include/linux/filter.h | 1 + > include/uapi/linux/bpf.h | 26 ++ > kernel/bpf/core.c | 67 ++++- > kernel/bpf/disasm.c | 33 ++- > kernel/bpf/syscall.c | 115 ++++++++ > kernel/bpf/verifier.c | 58 +++- > tools/bpf/bpftool/prog.c | 14 + > tools/bpf/bpftool/xlated_dumper.c | 18 ++ > tools/bpf/bpftool/xlated_dumper.h | 2 + > tools/include/uapi/linux/bpf.h | 26 ++ > .../bpf/prog_tests/bpf_insns_mappings.c | 156 ++++++++++ > .../bpf/prog_tests/bpf_static_branches.c | 269 ++++++++++++++++++ > .../selftests/bpf/progs/bpf_insns_mappings.c | 155 ++++++++++ > 16 files changed, 1002 insertions(+), 23 deletions(-) > create mode 100644 tools/testing/selftests/bpf/prog_tests/bpf_insns_mappings.c > create mode 100644 tools/testing/selftests/bpf/prog_tests/bpf_static_branches.c > create mode 100644 tools/testing/selftests/bpf/progs/bpf_insns_mappings.c > > -- > 2.34.1 > This fails to build in CI ([0]). I'll take a look at the patches next week, sorry for the delay. [0] https://github.com/kernel-patches/bpf/actions/runs/7762232524/job/21172303431?pr=6380#step:11:77
