[PATCH bpf-next v4 00/16] BPF support for global data

[Daniel Borkmann <daniel@iogearbox.net>]

This series is a major rework of previously submitted libbpf
patches [0] in order to add global data support for BPF. The
kernel has been extended to add proper infrastructure that allows
for full .bss/.data/.rodata sections on BPF loader side based
upon feedback from LPC discussions [1]. Latter support is then
also added into libbpf in this series which allows for more
natural C-like programming of BPF programs. For more information
on loader, please refer to 'bpf, libbpf: support global data/bss/
rodata sections' patch in this series.

Thanks a lot!

  v3 -> v4:
   - Various fixes in BTF verification e.g. to disallow
     Var and DataSec to be an intermediate type during resolve (Martin)
   - More BTF test cases added
   - Few cleanups in key-less BTF commit (Martin)
   - Bump libbpf minor version from 2 to 3
   - Renamed and simplified read-only locking
   - Various minor improvements all over the place
  v2 -> v3:
   - Implement BTF support in kernel, libbpf, bpftool, add tests
   - Fix idx + off conversion (Andrii)
   - Document lower / higher bits for direct value access (Andrii)
   - Add tests with small value size (Andrii)
   - Add index selection into ldimm64 (Andrii)
   - Fix missing fdput() (Jann)
   - Reject invalid flags in BPF_F_*_PROG (Jakub)
   - Complete rework of libbpf support, includes:
    - Add objname to map name (Stanislav)
    - Make .rodata map full read-only after setup (Andrii)
    - Merge relocation handling into single one (Andrii)
    - Store global maps into obj->maps array (Andrii, Alexei)
    - Debug message when skipping section (Andrii)
    - Reject non-static global data till we have
      semantics for sharing them (Yonghong, Andrii, Alexei)
    - More test cases and completely reworked prog test (Alexei)
   - Fixes, cleanups, etc all over the set
   - Not yet addressed:
    - Make BTF mandatory for these maps (Alexei)
    -> Waiting till BTF support for these lands first
  v1 -> v2:
    - Instead of 32-bit static data, implement full global
      data support (Alexei)

  [0] https://patchwork.ozlabs.org/cover/1040290/
  [1] http://vger.kernel.org/lpc-bpf2018.html#session-3

Daniel Borkmann (14):
  bpf: implement lookup-free direct value access for maps
  bpf: do not retain flags that are not tied to map lifetime
  bpf: add program side {rd,wr}only support for maps
  bpf: add syscall side map freeze support
  bpf: allow . char as part of the object name
  bpf: add specification for BTF Var and DataSec kinds
  bpf: kernel side support for BTF Var and DataSec
  bpf: allow for key-less BTF in array map
  bpf: sync {btf,bpf}.h uapi header from tools infrastructure
  bpf, libbpf: support global data/bss/rodata sections
  bpf, libbpf: add support for BTF Var and DataSec
  bpf: bpftool support for dumping data/bss/rodata sections
  bpf, selftest: test {rd,wr}only flags and direct value access
  bpf, selftest: add test cases for BTF Var and DataSec

Joe Stringer (2):
  bpf, libbpf: refactor relocation handling
  bpf, selftest: test global data/bss/rodata sections

 Documentation/bpf/btf.rst                          |  57 ++
 include/linux/bpf.h                                |  33 +-
 include/linux/bpf_verifier.h                       |   4 +
 include/linux/btf.h                                |   1 +
 include/uapi/linux/bpf.h                           |  24 +-
 include/uapi/linux/btf.h                           |  32 +-
 kernel/bpf/arraymap.c                              |  50 +-
 kernel/bpf/btf.c                                   | 419 ++++++++++++-
 kernel/bpf/core.c                                  |   3 +-
 kernel/bpf/disasm.c                                |   5 +-
 kernel/bpf/hashtab.c                               |   6 +-
 kernel/bpf/local_storage.c                         |   6 +-
 kernel/bpf/lpm_trie.c                              |   3 +-
 kernel/bpf/queue_stack_maps.c                      |   6 +-
 kernel/bpf/syscall.c                               | 135 ++++-
 kernel/bpf/verifier.c                              | 155 ++++-
 tools/bpf/bpftool/btf_dumper.c                     |  59 ++
 tools/bpf/bpftool/map.c                            |  10 +-
 tools/bpf/bpftool/xlated_dumper.c                  |   6 +
 tools/include/linux/filter.h                       |  14 +
 tools/include/uapi/linux/bpf.h                     |  24 +-
 tools/include/uapi/linux/btf.h                     |  32 +-
 tools/lib/bpf/Makefile                             |   2 +-
 tools/lib/bpf/bpf.c                                |  10 +
 tools/lib/bpf/bpf.h                                |   1 +
 tools/lib/bpf/btf.c                                |  97 ++-
 tools/lib/bpf/btf.h                                |   3 +
 tools/lib/bpf/libbpf.c                             | 546 ++++++++++++++---
 tools/lib/bpf/libbpf.h                             |   5 +
 tools/lib/bpf/libbpf.map                           |   7 +
 tools/testing/selftests/bpf/bpf_helpers.h          |   8 +-
 .../testing/selftests/bpf/prog_tests/global_data.c | 157 +++++
 .../testing/selftests/bpf/progs/test_global_data.c | 106 ++++
 tools/testing/selftests/bpf/test_btf.c             | 665 ++++++++++++++++++++-
 tools/testing/selftests/bpf/test_verifier.c        |  53 +-
 .../testing/selftests/bpf/verifier/array_access.c  | 159 +++++
 .../selftests/bpf/verifier/direct_value_access.c   | 262 ++++++++
 37 files changed, 2951 insertions(+), 214 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/global_data.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_global_data.c
 create mode 100644 tools/testing/selftests/bpf/verifier/direct_value_access.c

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2.9.5