This set enables kernel module function calls, and also modifies verifier logic to permit invalid kernel function calls as long as they are pruned as part of dead code elimination. This is done to provide better runtime portability for BPF objects, which can conditionally disable parts of code that are pruned later by the verifier (e.g. const volatile vars, kconfig options). libbpf modifications are made along with kernel changes to support module function calls. It also converts TCP congestion control objects to use the module kfunc support instead of relying on IS_BUILTIN ifdef. Kumar Kartikeya Dwivedi (8): bpf: Introduce BPF support for kernel module function calls bpf: Be conservative during verification for invalid kfunc calls libbpf: Support kernel module function calls libbpf: Resolve invalid kfunc calls with imm = 0, off = 0 tools: Allow specifying base BTF file in resolve_btfids bpf: btf: Introduce helpers for dynamic BTF set registration bpf: enable TCP congestion control kfunc from modules bpf, selftests: Add basic test for module kfunc call include/linux/bpf.h | 1 + include/linux/bpfptr.h | 1 + include/linux/btf.h | 18 +++ include/linux/filter.h | 9 ++ include/uapi/linux/bpf.h | 3 +- kernel/bpf/btf.c | 37 +++++++ kernel/bpf/core.c | 14 +++ kernel/bpf/syscall.c | 55 +++++++++- kernel/bpf/verifier.c | 103 ++++++++++++++---- kernel/trace/bpf_trace.c | 1 + net/ipv4/bpf_tcp_ca.c | 34 +----- net/ipv4/tcp_bbr.c | 28 ++++- net/ipv4/tcp_cubic.c | 26 ++++- net/ipv4/tcp_dctcp.c | 26 ++++- scripts/Makefile.modfinal | 1 + tools/bpf/resolve_btfids/main.c | 19 +++- tools/include/uapi/linux/bpf.h | 3 +- tools/lib/bpf/bpf.c | 3 + tools/lib/bpf/libbpf.c | 91 ++++++++++++++-- tools/lib/bpf/libbpf_internal.h | 2 + tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 23 +++- .../selftests/bpf/prog_tests/ksyms_module.c | 10 +- .../selftests/bpf/progs/test_ksyms_module.c | 9 ++ 24 files changed, 446 insertions(+), 74 deletions(-) -- 2.33.0
