On 3/22/24 5:26 AM, Jiri Olsa wrote:
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
The goal is to include those kernel functions filtered in patch 4.
But we cannot use the names from available_filter_functions[_addrs],
and we need to get names from /proc/kallsyms. Hence this patch.
This will test if we give names (<name>.llvm.<hash>) to kernel
for kprobe_multi_attach, things will be okay.
+ *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
I will give a try in the next revision.
+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
Okay, I will put it in serial mode in next revision.
jirka
