On 2025/10/20 16:18, Jiri Olsa wrote: > On Sat, Oct 18, 2025 at 10:21:19PM +0800, Menglong Dong wrote: > > 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. > > hi, > I think it'd be useful to have support for cookie, people that use kprobe > session because of multi attach, could easily migrate to trampolines once > we have fast multi attach for trampolines
OK, I'll implement it in the next version. > > jirka > > > > > > 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 > > > >
