Commit d459dbbb authored by Ilya Leoshkevich's avatar Ilya Leoshkevich Committed by Alexei Starovoitov
Browse files

selftests/bpf: Stress test attaching a BPF prog to another BPF prog 



Add a test that invokes a BPF prog in a loop, while concurrently
attaching and detaching another BPF prog to and from it. This helps
identifying race conditions in bpf_arch_text_poke().

Signed-off-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20250716194524.48109-3-iii@linux.ibm.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 6a5abf8c

tools/testing/selftests/bpf/prog_tests/recursive_attach.c

+67 −0
Original line number Diff line number Diff line
@@ -149,3 +149,70 @@ void test_fentry_attach_btf_presence(void) 
	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);

}