On Tue, May 26, 2026 at 10:58 PM +02, Jiri Olsa wrote:
> Adding reattach tests for uprobe syscall tests to make sure
> we can re-attach and optimize same uprobe multiple times.
>
> Signed-off-by: Jiri Olsa <[email protected]>
> ---
> .../selftests/bpf/prog_tests/uprobe_syscall.c | 114 ++++++++++++++++--
> 1 file changed, 104 insertions(+), 10 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> index 0868fb9793e0..969f4deba9fd 100644
> --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
> @@ -430,23 +430,28 @@ static void *check_attach(struct
> uprobe_syscall_executed *skel, trigger_t trigge
> return tramp;
> }
>
> -static void check_detach(void *addr, void *tramp)
> +static bool check_detach(void *addr, void *tramp)
> {
> static const char nop10_prefix[] = { 0x66, 0x2e, 0x0f, 0x1f, 0x84 };
> + bool ok = true;
>
> /* [uprobes_trampoline] stays after detach */
> - ASSERT_OK(find_uprobes_trampoline(tramp), "uprobes_trampoline");
> - ASSERT_OK(memcmp(addr, nop10_prefix, 5), "nop10_prefix");
> + if (!ASSERT_OK(find_uprobes_trampoline(tramp), "uprobes_trampoline"))
> + ok = false;
> + if (!ASSERT_OK(memcmp(addr, nop10_prefix, 5), "nop10_prefix"))
> + ok = false;
> + return ok;
> }
Nit: Maybe apply the same pattern you used in
progs/get_func_args_test.c?
ok &= ASSERT_OK(...)
ok &= ASSERT_OK(...)
>
> -static void check(struct uprobe_syscall_executed *skel, struct bpf_link
> *link,
> - trigger_t trigger, void *addr, int executed)
> +static void *check(struct uprobe_syscall_executed *skel, struct bpf_link
> *link,
> + trigger_t trigger, void *addr, int executed)
Nit: Kinda wish that was called check_attach_detach().
> {
> void *tramp;
>
> tramp = check_attach(skel, trigger, addr, executed);
> bpf_link__destroy(link);
> check_detach(addr, tramp);
> + return tramp;
> }
>
> static void test_uprobe_legacy(void)
> @@ -457,6 +462,7 @@ static void test_uprobe_legacy(void)
> );
> struct bpf_link *link;
> unsigned long offset;
> + void *tramp;
>
> offset = get_uprobe_offset(&uprobe_test);
> if (!ASSERT_GE(offset, 0, "get_uprobe_offset"))
> @@ -474,7 +480,28 @@ static void test_uprobe_legacy(void)
> if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts"))
> goto cleanup;
>
> - check(skel, link, uprobe_test, uprobe_test, 2);
> + tramp = check(skel, link, uprobe_test, uprobe_test, 2);
> +
> + /* reattach and detach without triggering optimization */
> + link = bpf_program__attach_uprobe_opts(skel->progs.test_uprobe,
> + 0, "/proc/self/exe", offset,
> NULL);
> + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts"))
> + goto cleanup;
> +
In theory we're missing a check here that an unoptimized uprobe was
installed. If nothing happened at all between the last check() and
check_destroy() below, the test would still pass.
Applies to the three similar changes after that one as well.
> + bpf_link__destroy(link);
> + if (!check_detach(uprobe_test, tramp))
> + goto cleanup;
> +
> + uprobe_test();
> + ASSERT_EQ(skel->bss->executed, 2, "executed_no_probe");
> +
> + /* reattach with triggering optimization */
> + link = bpf_program__attach_uprobe_opts(skel->progs.test_uprobe,
> + 0, "/proc/self/exe", offset, NULL);
> + if (!ASSERT_OK_PTR(link, "bpf_program__attach_uprobe_opts"))
> + goto cleanup;
> +
> + check(skel, link, uprobe_test, uprobe_test, 4);
>
> /* uretprobe */
> skel->bss->executed = 0;
[...]
