On Thu, Mar 21, 2024 at 01:01:24PM -0700, Yonghong Song wrote:
> The current kprobe_multi_bench_attach/kernel test
> reads sym names from /sys/kernel/tracing/available_filter_functions.
> Some names do not agree with the corresponding entries in /proc/kallsyms
> since the corresponding /proc/kallsyms syms have suffix '.llvm.<hash>'.
> Actually, if we pass symbol names in /proc/kallsyms,
> kprobe_multi_attach will be okay.
>
> This patch added a new subtest where addresses are retrieved from
> /sys/kernel/tracing/available_filter_functions_addrs, and use the
> address to consule /proc/kallsyms to get the function name.
hm, I don't understand the reason for this test.. AFAICS test_kprobe_multi_bench_attach
is doing that already, just reading available_filter_functions file
both available_filter_functions_addrs and available_filter_functions have the
same functions, there's just extra addresses in available_filter_functions_addrs
> + *symsp = syms;
> + *cntp = cnt;
> +
> +error:
> + fclose(f);
> + hashmap__free(map);
> + if (err) {
> + for (i = 0; i < cnt; i++)
> + free(syms[i]);
> + free(syms);
> + }
> + return err;
> +}
> +
> static void test_kprobe_multi_bench_attach(bool kernel)
> {
> LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
> @@ -521,6 +617,47 @@ static void test_attach_override(void)
> kprobe_multi_override__destroy(skel);
> }
there's lot of duplicated code in both
get_syms_from_addr/get_syms
test_attach_kernel_addrs_to_sym/test_kprobe_multi_bench_attach
would be great to put it together
>
> +static void test_attach_kernel_addrs_to_sym(void)
> +{
> + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
> + struct kprobe_multi_empty *skel;
> + struct bpf_link *link;
> + char **syms = NULL;
> + size_t cnt = 0;
> + int i, err;
> +
> + err = get_syms_from_addr(&syms, &cnt);
> + if (err == -ENOENT) {
> + test__skip();
> + return;
> + }
> + if (!ASSERT_OK(err, "get_syms_from_addr"))
> + return;
> +
> + skel = kprobe_multi_empty__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "kprobe_multi_empty__open_and_load"))
> + goto cleanup;
> +
> + opts.syms = (const char **) syms;
> + opts.cnt = cnt;
> +
> + link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe_empty,
> + NULL, &opts);
> +
> + if (!ASSERT_OK_PTR(link, "bpf_program__attach_kprobe_multi_opts"))
> + goto cleanup;
> +
> + bpf_link__destroy(link);
> +
> +cleanup:
> + kprobe_multi_empty__destroy(skel);
> + if (syms) {
> + for (i = 0; i < cnt; i++)
> + free(syms[i]);
> + free(syms);
> + }
> +}
> +
> void serial_test_kprobe_multi_bench_attach(void)
> {
> if (test__start_subtest("kernel"))
> @@ -550,4 +687,6 @@ void test_kprobe_multi_test(void)
> test_attach_api_fails();
> if (test__start_subtest("attach_override"))
> test_attach_override();
> + if (test__start_subtest("kernel_addrs_to_sym"))
> + test_attach_kernel_addrs_to_sym();
we moved the bench subtests to serial_test_kprobe_multi_bench_attach,
not to clash with others in parallel mode
jirka
