From: Martin KaFai Lau <kafai@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>,
<netdev@vger.kernel.org>
Subject: [PATCH v2 bpf-next 00/14] bpf: Support calling kernel function
Date: Wed, 24 Mar 2021 18:51:24 -0700 [thread overview]
Message-ID: <20210325015124.1543397-1-kafai@fb.com> (raw)
This series adds support to allow bpf program calling kernel function.
The use case included in this set is to allow bpf-tcp-cc to directly
call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()"). Those
functions have already been used by some kernel tcp-cc implementations.
This set will also allow the bpf-tcp-cc program to directly call the
kernel tcp-cc implementation, For example, a bpf_dctcp may only want to
implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly
from the kernel tcp_dctcp.c instead of reimplementing (or
copy-and-pasting) them.
The tcp-cc kernel functions mentioned above will be white listed
for the struct_ops bpf-tcp-cc programs to use in a later patch.
The white listed functions are not bounded to a fixed ABI contract.
Those functions have already been used by the existing kernel tcp-cc.
If any of them has changed, both in-tree and out-of-tree kernel tcp-cc
implementations have to be changed. The same goes for the struct_ops
bpf-tcp-cc programs which have to be adjusted accordingly.
Please see individual patch for details.
v2:
- Patch 2 in v1 is removed. No need to support extern func in kernel.
Changed libbpf to adjust the .ksyms datasec for extern func
in patch 11. (Andrii)
- Name change: btf_check_func_arg_match() and btf_check_subprog_arg_match()
in patch 2. (Andrii)
- Always set unreliable on any error in patch 2 since it does not
matter. (Andrii)
- s/kern_func/kfunc/ and s/descriptor/desc/ in this set. (Andrii)
- Remove some unnecessary changes in disasm.h and disasm.c
in patch 3. In particular, no need to change the function
signature in bpf_insn_revmap_call_t. Also, removed the changes
in print_bpf_insn().
- Fixed an issue in check_kfunc_call() when the calling kernel function
returns a pointer in patch 3. Added a selftest.
- Adjusted the verifier selftests due to the changes in the verifier log
in patch 3.
- Fixed a comparison issue in kfunc_desc_cmp_by_imm() in patch 3. (Andrii)
- Name change: is_ldimm64_insn(),
new helper: is_call_insn() in patch 10 (Andrii)
- Move btf_func_linkage() from btf.h to libbpf.c in patch 11. (Andrii)
- Fixed the linker error when CONFIG_BPF_SYSCALL is not defined.
Moved the check_kfunc_call from filter.c to test_run.c in patch 14.
(kernel test robot)
Martin KaFai Lau (14):
bpf: Simplify freeing logic in linfo and jited_linfo
bpf: Refactor btf_check_func_arg_match
bpf: Support bpf program calling kernel function
bpf: Support kernel function call in x86-32
tcp: Rename bictcp function prefix to cubictcp
bpf: tcp: Put some tcp cong functions in allowlist for bpf-tcp-cc
libbpf: Refactor bpf_object__resolve_ksyms_btf_id
libbpf: Refactor codes for finding btf id of a kernel symbol
libbpf: Rename RELO_EXTERN to RELO_EXTERN_VAR
libbpf: Record extern sym relocation first
libbpf: Support extern kernel function
bpf: selftests: Rename bictcp to bpf_cubic
bpf: selftests: bpf_cubic and bpf_dctcp calling kernel functions
bpf: selftests: Add kfunc_call test
arch/x86/net/bpf_jit_comp.c | 5 +
arch/x86/net/bpf_jit_comp32.c | 198 +++++++++
include/linux/bpf.h | 34 +-
include/linux/btf.h | 6 +
include/linux/filter.h | 4 +-
include/uapi/linux/bpf.h | 4 +
kernel/bpf/btf.c | 218 ++++++----
kernel/bpf/core.c | 47 +--
kernel/bpf/disasm.c | 13 +-
kernel/bpf/syscall.c | 4 +-
kernel/bpf/verifier.c | 376 +++++++++++++++--
net/bpf/test_run.c | 28 ++
net/core/filter.c | 1 +
net/ipv4/bpf_tcp_ca.c | 41 ++
net/ipv4/tcp_cubic.c | 24 +-
tools/include/uapi/linux/bpf.h | 4 +
tools/lib/bpf/libbpf.c | 389 +++++++++++++-----
tools/testing/selftests/bpf/bpf_tcp_helpers.h | 29 +-
.../selftests/bpf/prog_tests/kfunc_call.c | 59 +++
tools/testing/selftests/bpf/progs/bpf_cubic.c | 36 +-
tools/testing/selftests/bpf/progs/bpf_dctcp.c | 22 +-
.../selftests/bpf/progs/kfunc_call_test.c | 47 +++
.../bpf/progs/kfunc_call_test_subprog.c | 42 ++
tools/testing/selftests/bpf/verifier/calls.c | 12 +-
.../selftests/bpf/verifier/dead_code.c | 10 +-
25 files changed, 1334 insertions(+), 319 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_call.c
create mode 100644 tools/testing/selftests/bpf/progs/kfunc_call_test.c
create mode 100644 tools/testing/selftests/bpf/progs/kfunc_call_test_subprog.c
--
2.30.2
next reply other threads:[~2021-03-25 1:52 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-25 1:51 Martin KaFai Lau [this message]
2021-03-25 1:51 ` [PATCH v2 bpf-next 01/14] bpf: Simplify freeing logic in linfo and jited_linfo Martin KaFai Lau
2021-03-25 1:51 ` [PATCH v2 bpf-next 02/14] bpf: Refactor btf_check_func_arg_match Martin KaFai Lau
2021-03-25 1:51 ` [PATCH v2 bpf-next 03/14] bpf: Support bpf program calling kernel function Martin KaFai Lau
2021-03-25 22:02 ` Toke Høiland-Jørgensen
2021-03-25 23:09 ` Martin KaFai Lau
2021-03-26 10:11 ` Toke Høiland-Jørgensen
2021-03-26 14:20 ` Alexei Starovoitov
2021-03-26 15:14 ` Toke Høiland-Jørgensen
2021-03-27 3:59 ` Alexei Starovoitov
2021-03-25 1:51 ` [PATCH v2 bpf-next 04/14] bpf: Support kernel function call in x86-32 Martin KaFai Lau
2021-03-25 1:51 ` [PATCH v2 bpf-next 05/14] tcp: Rename bictcp function prefix to cubictcp Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 06/14] bpf: tcp: Put some tcp cong functions in allowlist for bpf-tcp-cc Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 07/14] libbpf: Refactor bpf_object__resolve_ksyms_btf_id Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 08/14] libbpf: Refactor codes for finding btf id of a kernel symbol Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 09/14] libbpf: Rename RELO_EXTERN to RELO_EXTERN_VAR Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 10/14] libbpf: Record extern sym relocation first Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 11/14] libbpf: Support extern kernel function Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 12/14] bpf: selftests: Rename bictcp to bpf_cubic Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 13/14] bpf: selftests: bpf_cubic and bpf_dctcp calling kernel functions Martin KaFai Lau
2021-03-25 1:52 ` [PATCH v2 bpf-next 14/14] bpf: selftests: Add kfunc_call test Martin KaFai Lau
2021-03-27 3:50 ` [PATCH v2 bpf-next 00/14] bpf: Support calling kernel function patchwork-bot+netdevbpf
2021-03-27 21:25 ` Cong Wang
2021-03-27 21:28 ` Alexei Starovoitov
2021-03-27 22:07 ` Cong Wang
2021-03-27 22:53 ` Alexei Starovoitov
2021-03-28 20:13 ` Cong Wang
2021-03-29 1:24 ` Martin KaFai Lau
2021-03-29 16:06 ` Lorenz Bauer
2021-03-29 19:08 ` Martin KaFai Lau
2021-03-31 6:44 ` Andrii Nakryiko
2021-04-01 19:51 ` Martin KaFai Lau
2021-04-01 19:52 ` Andrii Nakryiko
2021-03-29 20:18 ` Cong Wang
2021-03-30 9:43 ` Lorenz Bauer
2021-03-30 14:35 ` Alexei Starovoitov
2021-03-30 19:58 ` Cong Wang
2021-03-30 21:43 ` Martin KaFai Lau
2021-03-31 3:28 ` [External] " Jiang Wang .
2021-03-31 4:55 ` Martin KaFai Lau
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