Sometimes, we need to hook both the entry and exit of a function with TRACING. Therefore, we need define a FENTRY and a FEXIT for the target function, which is not convenient.
Therefore, we add a tracing session support for TRACING. Generally speaking, it's similar to kprobe session, which can hook both the entry and exit of a function with a single BPF program. Meanwhile, it can also control the execution of the fexit with the return value of the fentry. session cookie is not supported yet, and I'm not sure if it's necessary. For now, only x86_64 is supported. Other architectures will be supported later. Menglong Dong (5): bpf: add tracing session support bpf: add kfunc bpf_tracing_is_exit for TRACE_SESSION bpf,x86: add tracing session supporting for x86_64 libbpf: add support for tracing session selftests/bpf: add testcases for tracing session arch/arm64/net/bpf_jit_comp.c | 3 + arch/loongarch/net/bpf_jit.c | 3 + arch/powerpc/net/bpf_jit_comp.c | 3 + arch/riscv/net/bpf_jit_comp64.c | 3 + arch/s390/net/bpf_jit_comp.c | 3 + arch/x86/net/bpf_jit_comp.c | 115 ++++++++++- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 1 + kernel/bpf/btf.c | 2 + kernel/bpf/syscall.c | 2 + kernel/bpf/trampoline.c | 5 +- kernel/bpf/verifier.c | 17 +- kernel/trace/bpf_trace.c | 43 ++++- net/bpf/test_run.c | 1 + net/core/bpf_sk_storage.c | 1 + tools/bpf/bpftool/common.c | 1 + tools/include/uapi/linux/bpf.h | 1 + tools/lib/bpf/bpf.c | 2 + tools/lib/bpf/libbpf.c | 3 + .../selftests/bpf/prog_tests/fsession_test.c | 132 +++++++++++++ .../selftests/bpf/progs/fsession_test.c | 178 ++++++++++++++++++ 21 files changed, 511 insertions(+), 9 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/fsession_test.c create mode 100644 tools/testing/selftests/bpf/progs/fsession_test.c -- 2.51.0
