From: Jiri Olsa <olsajiri@gmail.com>
To: Hoyeon Lee <hoyeon.lee@suse.com>
Cc: bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Shuah Khan <shuah@kernel.org>, Feng Yang <yangfeng@kylinos.cn>,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH bpf-next v6 3/3] selftests/bpf: add test for raw-address single kprobe attach
Date: Wed, 1 Apr 2026 12:18:16 +0200 [thread overview]
Message-ID: <aczw6Mz5twb04Pcv@krava> (raw)
In-Reply-To: <20260401070738.122709-4-hoyeon.lee@suse.com>
On Wed, Apr 01, 2026 at 04:05:04PM +0900, Hoyeon Lee wrote:
> Currently, attach_probe covers manual single-kprobe attaches by
> func_name, but not the raw-address form that the PMU-based
> single-kprobe path can accept.
>
> This commit adds PERF and LINK raw-address coverage. It resolves
> SYS_NANOSLEEP_KPROBE_NAME through kallsyms, passes the absolute address
> in bpf_kprobe_opts.offset with func_name = NULL, and verifies that
> kprobe and kretprobe are still triggered. It also verifies that LEGACY
> rejects the same form.
left 2 nits below
Acked-by: Jiri Olsa <jolsa@kernel.org>
jirka
>
> Signed-off-by: Hoyeon Lee <hoyeon.lee@suse.com>
> ---
> .../selftests/bpf/prog_tests/attach_probe.c | 82 +++++++++++++++++++
> 1 file changed, 82 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
> index 9e77e5da7097..a41542f4b35d 100644
> --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c
> +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
> @@ -123,6 +123,82 @@ static void test_attach_probe_manual(enum probe_attach_mode attach_mode)
> test_attach_probe_manual__destroy(skel);
> }
>
> +/* manual attach address-based kprobe/kretprobe testings */
> +static void test_attach_kprobe_by_addr(enum probe_attach_mode attach_mode)
> +{
> + LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts);
> + struct test_attach_probe_manual *skel;
> + unsigned long func_addr;
> +
> + if (!ASSERT_OK(load_kallsyms(), "load_kallsyms"))
> + return;
> +
> + func_addr = ksym_get_addr(SYS_NANOSLEEP_KPROBE_NAME);
> + if (!ASSERT_NEQ(func_addr, 0UL, "func_addr"))
> + return;
> +
> + skel = test_attach_probe_manual__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "skel_kprobe_manual_open_and_load"))
> + return;
> +
> + kprobe_opts.attach_mode = attach_mode;
> + kprobe_opts.retprobe = false;
> + kprobe_opts.offset = func_addr;
> + skel->links.handle_kprobe =
> + bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe,
> + NULL, &kprobe_opts);
> + if (!ASSERT_OK_PTR(skel->links.handle_kprobe, "attach_kprobe_by_addr"))
> + goto cleanup;
> +
> + kprobe_opts.retprobe = true;
> + skel->links.handle_kretprobe =
> + bpf_program__attach_kprobe_opts(skel->progs.handle_kretprobe,
> + NULL, &kprobe_opts);
> + if (!ASSERT_OK_PTR(skel->links.handle_kretprobe,
> + "attach_kretprobe_by_addr"))
nit, no need to split the line
> + goto cleanup;
> +
> + /* trigger & validate kprobe && kretprobe */
> + usleep(1);
> +
> + ASSERT_EQ(skel->bss->kprobe_res, 1, "check_kprobe_res");
> + ASSERT_EQ(skel->bss->kretprobe_res, 2, "check_kretprobe_res");
> +
> +cleanup:
> + test_attach_probe_manual__destroy(skel);
> +}
> +
> +/* reject legacy address-based kprobe attach */
> +static void test_attach_kprobe_legacy_by_addr_reject(void)
> +{
> + LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts);
> + struct test_attach_probe_manual *skel;
> + unsigned long func_addr;
> +
> + if (!ASSERT_OK(load_kallsyms(), "load_kallsyms"))
> + return;
> +
> + func_addr = ksym_get_addr(SYS_NANOSLEEP_KPROBE_NAME);
> + if (!ASSERT_NEQ(func_addr, 0UL, "func_addr"))
> + return;
> +
> + skel = test_attach_probe_manual__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "skel_kprobe_manual_open_and_load"))
> + return;
> +
> + kprobe_opts.attach_mode = PROBE_ATTACH_MODE_LEGACY;
> + kprobe_opts.offset = func_addr;
> + skel->links.handle_kprobe =
> + bpf_program__attach_kprobe_opts(skel->progs.handle_kprobe,
> + NULL, &kprobe_opts);
> + if (ASSERT_ERR_PTR(skel->links.handle_kprobe,
> + "attach_kprobe_legacy_by_addr"))
> + ASSERT_EQ(libbpf_get_error(skel->links.handle_kprobe),
> + -EOPNOTSUPP, "attach_kprobe_legacy_by_addr_err");
nit, maybe we could do just:
ASSERT_ERR_PTR(skel->links.handle_kprobe, "attach_kprobe_legacy_by_addr");
ASSERT_EQ(libbpf_get_error(skel->links.handle_kprobe),
-EOPNOTSUPP, "attach_kprobe_legacy_by_addr_err");
> +
> + test_attach_probe_manual__destroy(skel);
> +}
> +
> /* attach uprobe/uretprobe long event name testings */
> static void test_attach_uprobe_long_event_name(void)
> {
> @@ -416,6 +492,12 @@ void test_attach_probe(void)
> test_attach_probe_manual(PROBE_ATTACH_MODE_PERF);
> if (test__start_subtest("manual-link"))
> test_attach_probe_manual(PROBE_ATTACH_MODE_LINK);
> + if (test__start_subtest("kprobe-perf-by-addr"))
> + test_attach_kprobe_by_addr(PROBE_ATTACH_MODE_PERF);
> + if (test__start_subtest("kprobe-link-by-addr"))
> + test_attach_kprobe_by_addr(PROBE_ATTACH_MODE_LINK);
> + if (test__start_subtest("kprobe-legacy-by-addr-reject"))
> + test_attach_kprobe_legacy_by_addr_reject();
>
> if (test__start_subtest("auto"))
> test_attach_probe_auto(skel);
> --
> 2.52.0
>
prev parent reply other threads:[~2026-04-01 10:18 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-01 7:05 [PATCH bpf-next v6 0/3] libbpf: clarify raw-address single kprobe attach behavior Hoyeon Lee
2026-04-01 7:05 ` [PATCH bpf-next v6 1/3] libbpf: use direct error codes for kprobe/uprobe attach Hoyeon Lee
2026-04-01 10:18 ` Jiri Olsa
2026-04-01 7:05 ` [PATCH bpf-next v6 2/3] libbpf: clarify raw-address single kprobe attach behavior Hoyeon Lee
2026-04-01 10:18 ` Jiri Olsa
2026-04-01 7:05 ` [PATCH bpf-next v6 3/3] selftests/bpf: add test for raw-address single kprobe attach Hoyeon Lee
2026-04-01 10:18 ` Jiri Olsa [this message]
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