From: Andrii Nakryiko <andriin@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
<daniel@iogearbox.net>, <yhs@fb.com>
Cc: <andrii.nakryiko@gmail.com>, <kernel-team@fb.com>,
Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH v2 bpf-next 0/5] Bitfield and size relocations support in libbpf
Date: Fri, 1 Nov 2019 15:28:05 -0700 [thread overview]
Message-ID: <20191101222810.1246166-1-andriin@fb.com> (raw)
This patch set adds support for reading bitfields in a relocatable manner
through a set of relocations emitted by Clang, corresponding libbpf support
for those relocations, as well as abstracting details into
BPF_CORE_READ_BITFIELD/BPF_CORE_READ_BITFIELD_PROBED macro.
We also add support for capturing relocatable field size, so that BPF program
code can adjust its logic to actual amount of data it needs to operate on,
even if it changes between kernels. New convenience macro is added to
bpf_core_read.h (bpf_core_field_size(), in the same family of macro as
bpf_core_read() and bpf_core_field_exists()). Corresponding set of selftests
are added to excercise this logic and validate correctness in a variety of
scenarios.
Some of the overly strict logic of matching fields is relaxed to support wider
variety of scenarios. See patch #1 for that.
Patch #1 removes few overly strict test cases.
Patch #2 adds support for bitfield-related relocations.
Patch #3 adds some further adjustments to support generic field size
relocations and introduces bpf_core_field_size() macro.
Patch #4 tests bitfield reading.
Patch #5 tests field size relocations.
v1->v2:
- added direct memory read-based macro and tests for bitfield reads.
Andrii Nakryiko (5):
selftests/bpf: remove too strict field offset relo test cases
libbpf: add support for relocatable bitfields
libbpf: add support for field size relocations
selftest/bpf: add relocatable bitfield reading tests
selftests/bpf: add field size relocation tests
tools/lib/bpf/bpf_core_read.h | 79 ++++++
tools/lib/bpf/libbpf.c | 243 +++++++++++++-----
tools/lib/bpf/libbpf_internal.h | 4 +
.../selftests/bpf/prog_tests/core_reloc.c | 123 ++++++++-
...__core_reloc_arrays___err_wrong_val_type.c | 3 +
..._core_reloc_arrays___err_wrong_val_type1.c | 3 -
..._core_reloc_arrays___err_wrong_val_type2.c | 3 -
.../bpf/progs/btf__core_reloc_bitfields.c | 3 +
...tf__core_reloc_bitfields___bit_sz_change.c | 3 +
...__core_reloc_bitfields___bitfield_vs_int.c | 3 +
...e_reloc_bitfields___err_too_big_bitfield.c | 3 +
...__core_reloc_bitfields___just_big_enough.c | 3 +
.../btf__core_reloc_ints___err_bitfield.c | 3 -
.../btf__core_reloc_ints___err_wrong_sz_16.c | 3 -
.../btf__core_reloc_ints___err_wrong_sz_32.c | 3 -
.../btf__core_reloc_ints___err_wrong_sz_64.c | 3 -
.../btf__core_reloc_ints___err_wrong_sz_8.c | 3 -
.../bpf/progs/btf__core_reloc_size.c | 3 +
.../progs/btf__core_reloc_size___diff_sz.c | 3 +
.../selftests/bpf/progs/core_reloc_types.h | 173 ++++++++-----
.../progs/test_core_reloc_bitfields_direct.c | 63 +++++
.../progs/test_core_reloc_bitfields_probed.c | 62 +++++
.../bpf/progs/test_core_reloc_size.c | 51 ++++
23 files changed, 682 insertions(+), 161 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_wrong_val_type.c
delete mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_wrong_val_type1.c
delete mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_wrong_val_type2.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_bitfields.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_bitfields___bit_sz_change.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_bitfields___bitfield_vs_int.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_bitfields___err_too_big_bitfield.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_bitfields___just_big_enough.c
delete mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_bitfield.c
delete mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_16.c
delete mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_32.c
delete mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_64.c
delete mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_8.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_size.c
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_size___diff_sz.c
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_bitfields_direct.c
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_bitfields_probed.c
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_size.c
--
2.17.1
next reply other threads:[~2019-11-01 22:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-01 22:28 Andrii Nakryiko [this message]
2019-11-01 22:28 ` [PATCH v2 bpf-next 1/5] selftests/bpf: remove too strict field offset relo test cases Andrii Nakryiko
2019-11-01 22:28 ` [PATCH v2 bpf-next 2/5] libbpf: add support for relocatable bitfields Andrii Nakryiko
2019-11-01 22:28 ` [PATCH v2 bpf-next 3/5] libbpf: add support for field size relocations Andrii Nakryiko
2019-11-01 22:28 ` [PATCH v2 bpf-next 4/5] selftest/bpf: add relocatable bitfield reading tests Andrii Nakryiko
2019-11-01 22:28 ` [PATCH v2 bpf-next 5/5] selftests/bpf: add field size relocation tests Andrii Nakryiko
2019-11-04 15:38 ` [PATCH v2 bpf-next 0/5] Bitfield and size relocations support in libbpf Daniel Borkmann
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