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.
Martin KaFai Lau (15):
bpf: Simplify freeing logic in linfo and jited_linfo
bpf: btf: Support parsing extern func
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: White list some tcp cong functions to be called by
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: selftest: bpf_cubic and bpf_dctcp calling kernel functions
bpf: selftest: Add kfunc_call test
arch/x86/net/bpf_jit_comp.c | 5 +
arch/x86/net/bpf_jit_comp32.c | 198 +++++++++
include/linux/bpf.h | 24 ++
include/linux/btf.h | 6 +
include/linux/filter.h | 4 +-
include/uapi/linux/bpf.h | 4 +
kernel/bpf/btf.c | 270 ++++++++-----
kernel/bpf/core.c | 47 +--
kernel/bpf/disasm.c | 32 +-
kernel/bpf/disasm.h | 3 +-
kernel/bpf/syscall.c | 4 +-
kernel/bpf/verifier.c | 380 ++++++++++++++++--
net/bpf/test_run.c | 11 +
net/core/filter.c | 11 +
net/ipv4/bpf_tcp_ca.c | 41 ++
net/ipv4/tcp_cubic.c | 24 +-
tools/bpf/bpftool/xlated_dumper.c | 3 +-
tools/include/uapi/linux/bpf.h | 4 +
tools/lib/bpf/btf.c | 32 +-
tools/lib/bpf/btf.h | 5 +
tools/lib/bpf/libbpf.c | 316 ++++++++++-----
tools/testing/selftests/bpf/bpf_tcp_helpers.h | 29 +-
tools/testing/selftests/bpf/prog_tests/btf.c | 154 ++++++-
.../selftests/bpf/prog_tests/kfunc_call.c | 61 +++
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 | 48 +++
.../bpf/progs/kfunc_call_test_subprog.c | 31 ++
28 files changed, 1454 insertions(+), 351 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
