From 6489b8e1e3cf0eb8639e96610002837c53a677cd Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 2 Mar 2020 20:31:59 -0800 Subject: [PATCH] selftests/bpf: Add link pinning selftests Add selftests validating link pinning/unpinning and associated BPF link (attachment) lifetime. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200303043159.323675-4-andriin@fb.com --- .../selftests/bpf/prog_tests/link_pinning.c | 105 ++++++++++++++++++ .../selftests/bpf/progs/test_link_pinning.c | 25 +++++ 2 files changed, 130 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/link_pinning.c create mode 100644 tools/testing/selftests/bpf/progs/test_link_pinning.c diff --git a/tools/testing/selftests/bpf/prog_tests/link_pinning.c b/tools/testing/selftests/bpf/prog_tests/link_pinning.c new file mode 100644 index 000000000000..a743288cf384 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/link_pinning.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include + +#include "test_link_pinning.skel.h" + +static int duration = 0; + +void test_link_pinning_subtest(struct bpf_program *prog, + struct test_link_pinning__bss *bss) +{ + const char *link_pin_path = "/sys/fs/bpf/pinned_link_test"; + struct stat statbuf = {}; + struct bpf_link *link; + int err, i; + + link = bpf_program__attach(prog); + if (CHECK(IS_ERR(link), "link_attach", "err: %ld\n", PTR_ERR(link))) + goto cleanup; + + bss->in = 1; + usleep(1); + CHECK(bss->out != 1, "res_check1", "exp %d, got %d\n", 1, bss->out); + + /* pin link */ + err = bpf_link__pin(link, link_pin_path); + if (CHECK(err, "link_pin", "err: %d\n", err)) + goto cleanup; + + CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path1", + "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link)); + + /* check that link was pinned */ + err = stat(link_pin_path, &statbuf); + if (CHECK(err, "stat_link", "err %d errno %d\n", err, errno)) + goto cleanup; + + bss->in = 2; + usleep(1); + CHECK(bss->out != 2, "res_check2", "exp %d, got %d\n", 2, bss->out); + + /* destroy link, pinned link should keep program attached */ + bpf_link__destroy(link); + link = NULL; + + bss->in = 3; + usleep(1); + CHECK(bss->out != 3, "res_check3", "exp %d, got %d\n", 3, bss->out); + + /* re-open link from BPFFS */ + link = bpf_link__open(link_pin_path); + if (CHECK(IS_ERR(link), "link_open", "err: %ld\n", PTR_ERR(link))) + goto cleanup; + + CHECK(strcmp(link_pin_path, bpf_link__pin_path(link)), "pin_path2", + "exp %s, got %s\n", link_pin_path, bpf_link__pin_path(link)); + + /* unpin link from BPFFS, program still attached */ + err = bpf_link__unpin(link); + if (CHECK(err, "link_unpin", "err: %d\n", err)) + goto cleanup; + + /* still active, as we have FD open now */ + bss->in = 4; + usleep(1); + CHECK(bss->out != 4, "res_check4", "exp %d, got %d\n", 4, bss->out); + + bpf_link__destroy(link); + link = NULL; + + /* Validate it's finally detached. + * Actual detachment might get delayed a bit, so there is no reliable + * way to validate it immediately here, let's count up for long enough + * and see if eventually output stops being updated + */ + for (i = 5; i < 10000; i++) { + bss->in = i; + usleep(1); + if (bss->out == i - 1) + break; + } + CHECK(i == 10000, "link_attached", "got to iteration #%d\n", i); + +cleanup: + if (!IS_ERR(link)) + bpf_link__destroy(link); +} + +void test_link_pinning(void) +{ + struct test_link_pinning* skel; + + skel = test_link_pinning__open_and_load(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + + if (test__start_subtest("pin_raw_tp")) + test_link_pinning_subtest(skel->progs.raw_tp_prog, skel->bss); + if (test__start_subtest("pin_tp_btf")) + test_link_pinning_subtest(skel->progs.tp_btf_prog, skel->bss); + + test_link_pinning__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_link_pinning.c b/tools/testing/selftests/bpf/progs/test_link_pinning.c new file mode 100644 index 000000000000..bbf2a5264dc0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_link_pinning.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include + +int in = 0; +int out = 0; + +SEC("raw_tp/sys_enter") +int raw_tp_prog(const void *ctx) +{ + out = in; + return 0; +} + +SEC("tp_btf/sys_enter") +int tp_btf_prog(const void *ctx) +{ + out = in; + return 0; +} + +char _license[] SEC("license") = "GPL";