Re: [PATCHv2 bpf-next 0/7] bpf, x86: Add bpf_get_func_ip helper

Jiri Olsa
2021-07-07T19:50:04Z

ugh forgot to cc Masami.. sorry, I can resend if needed

jirka

On Wed, Jul 07, 2021 at 09:46:12PM +0200, Jiri Olsa wrote:
> hi,
> adding bpf_get_func_ip helper that returns IP address of the
> caller function for trampoline and krobe programs.
>
> There're 2 specific implementation of the bpf_get_func_ip
> helper, one for trampoline progs and one for kprobe/kretprobe
> progs.
>
> The trampoline helper call is replaced/inlined by verifier
> with simple move instruction. The kprobe/kretprobe is actual
> helper call that returns prepared caller address.
>
> Also available at:
> https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
> bpf/get_func_ip
>
> v2 changes:
> - use kprobe_running to get kprobe instead of cpu var [Masami]
> - added support to add kprobe on function+offset
> and test for that [Alan]
>
> thanks,
> jirka
>
>
> ---
> Alan Maguire (1):
> libbpf: allow specification of "kprobe/function+offset"
>
> Jiri Olsa (6):
> bpf, x86: Store caller's ip in trampoline stack
> bpf: Enable BPF_TRAMP_F_IP_ARG for trampolines with call_get_func_ip
> bpf: Add bpf_get_func_ip helper for tracing programs
> bpf: Add bpf_get_func_ip helper for kprobe programs
> selftests/bpf: Add test for bpf_get_func_ip helper
> selftests/bpf: Add test for bpf_get_func_ip in kprobe+offset probe
>
> arch/x86/net/bpf_jit_comp.c | 19 +++++++++++++++++++
> include/linux/bpf.h | 5 +++++
> include/linux/filter.h | 3 ++-
> include/uapi/linux/bpf.h | 7 +++++++
> kernel/bpf/trampoline.c | 12 +++++++++---
> kernel/bpf/verifier.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> kernel/trace/bpf_trace.c | 32 ++++++++++++++++++++++++++++++++
> tools/include/uapi/linux/bpf.h | 7 +++++++
> tools/lib/bpf/libbpf.c | 20 +++++++++++++++++---
> tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> tools/testing/selftests/bpf/progs/get_func_ip_test.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 11 files changed, 270 insertions(+), 7 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c
> create mode 100644 tools/testing/selftests/bpf/progs/get_func_ip_test.c