On Wed, Apr 1, 2026 at 8:06 AM Andrii Nakryiko
<[email protected]> wrote:
>
> On Tue, Mar 31, 2026 at 8:25 AM Hoyeon Lee <[email protected]> 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 subtests by resolving
> > SYS_NANOSLEEP_KPROBE_NAME through kallsyms, passing the absolute address
> > in bpf_kprobe_opts.offset with func_name = NULL, and verifying that
> > kprobe and kretprobe are still triggered. It also verifies that LEGACY
> > rejects the same form.
> >
> > Signed-off-by: Hoyeon Lee <[email protected]>
> > ---
> > .../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..817c4794d54e 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)
> > +{
> > + DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts);
>
> DECLARE_LIBBPF_OPTS is a legacy backwards-compatibility macro, prefer
> using shorter LIBBPF_OPTS
>
Got it, I'll switch to LIBBPF_OPTS and updated the reject
expectation to -EOPNOTSUPP in v5.
> > + 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"))
> > + 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)
> > +{
> > + DECLARE_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),
> > -ENOTSUP,
> > + "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
> >
