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

Andrii Nakryiko
2021-07-07T21:00:53Z

On Wed, Jul 7, 2021 at 1:42 PM Jiri Olsa <jolsa@redhat.com> wrote:
>
> ugh forgot to cc Masami.. sorry, I can resend if needed

Can you please also add v2, v3, etc tags to *each patch*, not just
cover letter? It makes tracking different versions much easier.
Thanks!

>
> 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
>