From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Peter Zijlstra <peterz@infradead.org>,
"Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Subject: Re: [PATCHv2 bpf-next 0/6] bpf: Fixes for CONFIG_X86_KERNEL_IBT
Date: Mon, 15 Aug 2022 20:27:00 -0700 [thread overview]
Message-ID: <CAEf4BzaKWQtwki8oDcp+rh8c-kMmZcc1ok+zs=GvMCndN8UnyA@mail.gmail.com> (raw)
In-Reply-To: <20220811091526.172610-1-jolsa@kernel.org>
On Thu, Aug 11, 2022 at 2:15 AM Jiri Olsa <jolsa@kernel.org> wrote:
>
> hi,
> Martynas reported bpf_get_func_ip returning +4 address when
> CONFIG_X86_KERNEL_IBT option is enabled and I found there are
> some failing bpf tests when this option is enabled.
>
> The CONFIG_X86_KERNEL_IBT option adds endbr instruction at the
> function entry, so the idea is to 'fix' entry ip for kprobe_multi
> and trampoline probes, because they are placed on the function
> entry.
>
> v2 changes:
> - change kprobes get_func_ip to return zero for kprobes
> attached within the function body [Andrii]
> - detect IBT config and properly test kprobe with offset
> [Andrii]
>
> v1 changes:
> - read previous instruction in kprobe_multi link handler
> and adjust entry_ip for CONFIG_X86_KERNEL_IBT option
> - split first patch into 2 separate changes
> - update changelogs
>
> thanks,
> jirka
>
>
> ---
> Jiri Olsa (6):
> kprobes: Add new KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag
> ftrace: Keep the resolved addr in kallsyms_callback
> bpf: Use given function address for trampoline ip arg
> bpf: Adjust kprobe_multi entry_ip for CONFIG_X86_KERNEL_IBT
> bpf: Return value in kprobe get_func_ip only for entry address
> selftests/bpf: Fix get_func_ip offset test for CONFIG_X86_KERNEL_IBT
>
> arch/x86/net/bpf_jit_comp.c | 9 ++++-----
> include/linux/kprobes.h | 1 +
> kernel/kprobes.c | 6 +++++-
> kernel/trace/bpf_trace.c | 15 ++++++++++++++-
> kernel/trace/ftrace.c | 3 +--
> tools/testing/selftests/bpf/prog_tests/get_func_ip_test.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++-----------
> tools/testing/selftests/bpf/progs/get_func_ip_test.c | 22 ++++++++++------------
> tools/testing/selftests/bpf/progs/kprobe_multi.c | 4 +---
> 8 files changed, 87 insertions(+), 35 deletions(-)
Overall LGTM, please address Peter's questions and request for some
more comments and context. Few nits to simplify selftests further, but
looks great. Thanks!
prev parent reply other threads:[~2022-08-16 6:38 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-11 9:15 [PATCHv2 bpf-next 0/6] bpf: Fixes for CONFIG_X86_KERNEL_IBT Jiri Olsa
2022-08-11 9:15 ` [PATCHv2 bpf-next 1/6] kprobes: Add new KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag Jiri Olsa
2022-08-15 9:57 ` Peter Zijlstra
2022-08-15 10:10 ` Jiri Olsa
2022-08-15 12:40 ` Peter Zijlstra
2022-08-16 7:01 ` Jiri Olsa
2022-08-30 15:08 ` Jiri Olsa
2022-09-08 8:26 ` Jiri Olsa
2022-09-08 12:01 ` Masami Hiramatsu
2022-08-11 9:15 ` [PATCHv2 bpf-next 2/6] ftrace: Keep the resolved addr in kallsyms_callback Jiri Olsa
2022-08-15 10:13 ` Peter Zijlstra
2022-08-15 10:30 ` Jiri Olsa
2022-08-15 12:45 ` Peter Zijlstra
2022-08-16 7:06 ` Jiri Olsa
2022-09-08 12:35 ` Masami Hiramatsu
2022-09-08 19:41 ` Jiri Olsa
2022-08-11 9:15 ` [PATCHv2 bpf-next 3/6] bpf: Use given function address for trampoline ip arg Jiri Olsa
2022-08-15 10:18 ` Peter Zijlstra
2022-08-15 10:57 ` Jiri Olsa
2022-08-15 12:51 ` Peter Zijlstra
2022-08-17 13:40 ` Jiri Olsa
2022-08-11 9:15 ` [PATCHv2 bpf-next 4/6] bpf: Adjust kprobe_multi entry_ip for CONFIG_X86_KERNEL_IBT Jiri Olsa
2022-08-11 9:15 ` [PATCHv2 bpf-next 5/6] bpf: Return value in kprobe get_func_ip only for entry address Jiri Olsa
2022-08-11 9:15 ` [PATCHv2 bpf-next 6/6] selftests/bpf: Fix get_func_ip offset test for CONFIG_X86_KERNEL_IBT Jiri Olsa
2022-08-16 3:25 ` Andrii Nakryiko
2022-08-16 7:00 ` Jiri Olsa
2022-08-16 10:18 ` Jiri Olsa
2022-08-16 17:28 ` Andrii Nakryiko
2022-08-16 17:19 ` Andrii Nakryiko
2022-08-16 3:27 ` Andrii Nakryiko [this message]
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