diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/recursive_attach.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/recursive_attach.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/recursive_attach.c b/tools/testing/selftests/bpf/prog_tests/recursive_attach.c new file mode 100644 index 000000000000..0ffa01d54ce2 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/recursive_attach.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Red Hat, Inc. */ +#include <test_progs.h> +#include "fentry_recursive.skel.h" +#include "fentry_recursive_target.skel.h" +#include <bpf/btf.h> +#include "bpf/libbpf_internal.h" + +/* Test recursive attachment of tracing progs with more than one nesting level + * is not possible. Create a chain of attachment, verify that the last prog + * will fail. Depending on the arguments, following cases are tested: + * + * - Recursive loading of tracing progs, without attaching (attach = false, + * detach = false). The chain looks like this: + * load target + * load fentry1 -> target + * load fentry2 -> fentry1 (fail) + * + * - Recursive attach of tracing progs (attach = true, detach = false). The + * chain looks like this: + * load target + * load fentry1 -> target + * attach fentry1 -> target + * load fentry2 -> fentry1 (fail) + * + * - Recursive attach and detach of tracing progs (attach = true, detach = + * true). This validates that attach_tracing_prog flag will be set throughout + * the whole lifecycle of an fentry prog, independently from whether it's + * detached. The chain looks like this: + * load target + * load fentry1 -> target + * attach fentry1 -> target + * detach fentry1 + * load fentry2 -> fentry1 (fail) + */ +static void test_recursive_fentry_chain(bool attach, bool detach) +{ + struct fentry_recursive_target *target_skel = NULL; + struct fentry_recursive *tracing_chain[2] = {}; + struct bpf_program *prog; + int prev_fd, err; + + target_skel = fentry_recursive_target__open_and_load(); + if (!ASSERT_OK_PTR(target_skel, "fentry_recursive_target__open_and_load")) + return; + + /* Create an attachment chain with two fentry progs */ + for (int i = 0; i < 2; i++) { + tracing_chain[i] = fentry_recursive__open(); + if (!ASSERT_OK_PTR(tracing_chain[i], "fentry_recursive__open")) + goto close_prog; + + /* The first prog in the chain is going to be attached to the target + * fentry program, the second one to the previous in the chain. + */ + prog = tracing_chain[i]->progs.recursive_attach; + if (i == 0) { + prev_fd = bpf_program__fd(target_skel->progs.test1); + err = bpf_program__set_attach_target(prog, prev_fd, "test1"); + } else { + prev_fd = bpf_program__fd(tracing_chain[i-1]->progs.recursive_attach); + err = bpf_program__set_attach_target(prog, prev_fd, "recursive_attach"); + } + + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto close_prog; + + err = fentry_recursive__load(tracing_chain[i]); + /* The first attach should succeed, the second fail */ + if (i == 0) { + if (!ASSERT_OK(err, "fentry_recursive__load")) + goto close_prog; + + if (attach) { + err = fentry_recursive__attach(tracing_chain[i]); + if (!ASSERT_OK(err, "fentry_recursive__attach")) + goto close_prog; + } + + if (detach) { + /* Flag attach_tracing_prog should still be set, preventing + * attachment of the following prog. + */ + fentry_recursive__detach(tracing_chain[i]); + } + } else { + if (!ASSERT_ERR(err, "fentry_recursive__load")) + goto close_prog; + } + } + +close_prog: + fentry_recursive_target__destroy(target_skel); + for (int i = 0; i < 2; i++) { + fentry_recursive__destroy(tracing_chain[i]); + } +} + +void test_recursive_fentry(void) +{ + if (test__start_subtest("attach")) + test_recursive_fentry_chain(true, false); + if (test__start_subtest("load")) + test_recursive_fentry_chain(false, false); + if (test__start_subtest("detach")) + test_recursive_fentry_chain(true, true); +} + +/* Test that a tracing prog reattachment (when we land in + * "prog->aux->dst_trampoline and tgt_prog is NULL" branch in + * bpf_tracing_prog_attach) does not lead to a crash due to missing attach_btf + */ +void test_fentry_attach_btf_presence(void) +{ + struct fentry_recursive_target *target_skel = NULL; + struct fentry_recursive *tracing_skel = NULL; + struct bpf_program *prog; + int err, link_fd, tgt_prog_fd; + + target_skel = fentry_recursive_target__open_and_load(); + if (!ASSERT_OK_PTR(target_skel, "fentry_recursive_target__open_and_load")) + goto close_prog; + + tracing_skel = fentry_recursive__open(); + if (!ASSERT_OK_PTR(tracing_skel, "fentry_recursive__open")) + goto close_prog; + + prog = tracing_skel->progs.recursive_attach; + tgt_prog_fd = bpf_program__fd(target_skel->progs.fentry_target); + err = bpf_program__set_attach_target(prog, tgt_prog_fd, "fentry_target"); + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto close_prog; + + err = fentry_recursive__load(tracing_skel); + if (!ASSERT_OK(err, "fentry_recursive__load")) + goto close_prog; + + tgt_prog_fd = bpf_program__fd(tracing_skel->progs.recursive_attach); + link_fd = bpf_link_create(tgt_prog_fd, 0, BPF_TRACE_FENTRY, NULL); + if (!ASSERT_GE(link_fd, 0, "link_fd")) + goto close_prog; + + fentry_recursive__detach(tracing_skel); + + err = fentry_recursive__attach(tracing_skel); + ASSERT_ERR(err, "fentry_recursive__attach"); + +close_prog: + fentry_recursive_target__destroy(target_skel); + fentry_recursive__destroy(tracing_skel); +} + +static void *fentry_target_test_run(void *arg) +{ + for (;;) { + int prog_fd = __atomic_load_n((int *)arg, __ATOMIC_SEQ_CST); + LIBBPF_OPTS(bpf_test_run_opts, topts); + int err; + + if (prog_fd == -1) + break; + err = bpf_prog_test_run_opts(prog_fd, &topts); + if (!ASSERT_OK(err, "fentry_target test_run")) + break; + } + + return NULL; +} + +void test_fentry_attach_stress(void) +{ + struct fentry_recursive_target *target_skel = NULL; + struct fentry_recursive *tracing_skel = NULL; + struct bpf_program *prog; + int err, i, tgt_prog_fd; + pthread_t thread; + + target_skel = fentry_recursive_target__open_and_load(); + if (!ASSERT_OK_PTR(target_skel, + "fentry_recursive_target__open_and_load")) + goto close_prog; + tgt_prog_fd = bpf_program__fd(target_skel->progs.fentry_target); + err = pthread_create(&thread, NULL, + fentry_target_test_run, &tgt_prog_fd); + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto close_prog; + + for (i = 0; i < 1000; i++) { + tracing_skel = fentry_recursive__open(); + if (!ASSERT_OK_PTR(tracing_skel, "fentry_recursive__open")) + goto stop_thread; + + prog = tracing_skel->progs.recursive_attach; + err = bpf_program__set_attach_target(prog, tgt_prog_fd, + "fentry_target"); + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto stop_thread; + + err = fentry_recursive__load(tracing_skel); + if (!ASSERT_OK(err, "fentry_recursive__load")) + goto stop_thread; + + err = fentry_recursive__attach(tracing_skel); + if (!ASSERT_OK(err, "fentry_recursive__attach")) + goto stop_thread; + + fentry_recursive__destroy(tracing_skel); + tracing_skel = NULL; + } + +stop_thread: + __atomic_store_n(&tgt_prog_fd, -1, __ATOMIC_SEQ_CST); + err = pthread_join(thread, NULL); + ASSERT_OK(err, "pthread_join"); +close_prog: + fentry_recursive__destroy(tracing_skel); + fentry_recursive_target__destroy(target_skel); +} |