Add a test to verify that it is OK to iter the percpu_array map used for global percpu data.
Signed-off-by: Leon Hwang <[email protected]> --- .../bpf/prog_tests/global_data_init.c | 52 +++++++++++++++++++ .../bpf/progs/test_global_percpu_data.c | 25 +++++++++ 2 files changed, 77 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/global_data_init.c b/tools/testing/selftests/bpf/prog_tests/global_data_init.c index c3b9423246b5..6c1813ffe5f3 100644 --- a/tools/testing/selftests/bpf/prog_tests/global_data_init.c +++ b/tools/testing/selftests/bpf/prog_tests/global_data_init.c @@ -333,6 +333,56 @@ static void test_global_percpu_data_xlated(void) free(insns); } +static void test_global_percpu_data_iter(void) +{ + DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); + struct test_global_percpu_data *skel; + union bpf_iter_link_info linfo = {}; + struct bpf_link *link = NULL; + int fd, num_cpus, len, err; + char buf[16]; + + num_cpus = libbpf_num_possible_cpus(); + if (!ASSERT_GT(num_cpus, 0, "libbpf_num_possible_cpus")) + return; + + skel = test_global_percpu_data__open(); + if (!ASSERT_OK_PTR(skel, "test_global_percpu_data__open")) + return; + + skel->rodata->num_cpus = num_cpus; + skel->rodata->offsetof_num = offsetof(struct test_global_percpu_data__percpu, struct_data); + skel->rodata->offsetof_num += sizeof(skel->percpu->struct_data) - sizeof(int); + skel->rodata->elem_sz = roundup(sizeof(struct test_global_percpu_data__percpu), 8); + skel->percpu->struct_data.nums[6] = 0xc0de; + + err = test_global_percpu_data__load(skel); + if (!ASSERT_OK(err, "test_global_percpu_data__load")) + goto out; + + linfo.map.map_fd = bpf_map__fd(skel->maps.percpu); + opts.link_info = &linfo; + opts.link_info_len = sizeof(linfo); + link = bpf_program__attach_iter(skel->progs.dump_percpu_data, &opts); + if (!ASSERT_OK_PTR(link, "bpf_program__attach_iter")) + goto out; + + fd = bpf_iter_create(bpf_link__fd(link)); + if (!ASSERT_GE(fd, 0, "bpf_iter_create")) + goto out; + + while ((len = read(fd, buf, sizeof(buf))) > 0) + do { } while (0); + ASSERT_EQ(len, 0, "read iter"); + ASSERT_TRUE(skel->bss->run_iter, "run_iter"); + ASSERT_EQ(skel->bss->percpu_data_sum, 0xc0de * num_cpus, "percpu_data_sum"); + + close(fd); +out: + bpf_link__destroy(link); + test_global_percpu_data__destroy(skel); +} + void test_global_percpu_data(void) { if (!feat_supported(NULL, FEAT_PERCPU_DATA)) { @@ -348,4 +398,6 @@ void test_global_percpu_data(void) test_global_percpu_data_verifier_log(); if (test__start_subtest("xlated")) test_global_percpu_data_xlated(); + if (test__start_subtest("iter")) + test_global_percpu_data_iter(); } diff --git a/tools/testing/selftests/bpf/progs/test_global_percpu_data.c b/tools/testing/selftests/bpf/progs/test_global_percpu_data.c index 9a1b1a314c2f..037c8a05be4b 100644 --- a/tools/testing/selftests/bpf/progs/test_global_percpu_data.c +++ b/tools/testing/selftests/bpf/progs/test_global_percpu_data.c @@ -62,4 +62,29 @@ int verifier_percpu_read(void *ctx) return c == ' '; } +volatile const __u32 num_cpus = 0; +volatile const int offsetof_num; +volatile const int elem_sz; +__u32 percpu_data_sum = 0; +bool run_iter = false; + +SEC("iter/bpf_map_elem") +__auxiliary +int dump_percpu_data(struct bpf_iter__bpf_map_elem *ctx) +{ + void *pptr = ctx->value; + int i; + + if (!pptr) + return 0; + + run_iter = true; + + for (i = 0; i < num_cpus; i++) { + percpu_data_sum += *(int *) (pptr + offsetof_num); + pptr += elem_sz; + } + return 0; +} + char _license[] SEC("license") = "GPL"; -- 2.54.0
