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

// SPDX-License-Identifier: GPL-2.0

#define _GNU_SOURCE
#include <sched.h>
#include <test_progs.h>
#include <pthread.h>
#include <network_helpers.h>

#include "timer_lockup.skel.h"

static long cpu;
static int *timer1_err;
static int *timer2_err;
static bool skip;

volatile int k = 0;

static void *timer_lockup_thread(void *arg)
{
	LIBBPF_OPTS(bpf_test_run_opts, opts,
		.data_in	= &pkt_v4,
		.data_size_in	= sizeof(pkt_v4),
		.repeat		= 1000,
	);
	int i, prog_fd = *(int *)arg;
	cpu_set_t cpuset;

	CPU_ZERO(&cpuset);
	CPU_SET(__sync_fetch_and_add(&cpu, 1), &cpuset);
	ASSERT_OK(pthread_setaffinity_np(pthread_self(), sizeof(cpuset),
				         &cpuset),
		  "cpu affinity");

	for (i = 0; !READ_ONCE(*timer1_err) && !READ_ONCE(*timer2_err); i++) {
		bpf_prog_test_run_opts(prog_fd, &opts);
		/* Skip the test if we can't reproduce the race in a reasonable
		 * amount of time.
		 */
		if (i > 50) {
			WRITE_ONCE(skip, true);
			break;
		}
	}

	return NULL;
}

void test_timer_lockup(void)
{
	int timer1_prog, timer2_prog;
	struct timer_lockup *skel;
	pthread_t thrds[2];
	void *ret;

	skel = timer_lockup__open_and_load();
	if (!ASSERT_OK_PTR(skel, "timer_lockup__open_and_load"))
		return;

	timer1_prog = bpf_program__fd(skel->progs.timer1_prog);
	timer2_prog = bpf_program__fd(skel->progs.timer2_prog);

	timer1_err = &skel->bss->timer1_err;
	timer2_err = &skel->bss->timer2_err;

	if (!ASSERT_OK(pthread_create(&thrds[0], NULL, timer_lockup_thread,
				      &timer1_prog),
		       "pthread_create thread1"))
		goto out;
	if (!ASSERT_OK(pthread_create(&thrds[1], NULL, timer_lockup_thread,
				      &timer2_prog),
		       "pthread_create thread2")) {
		pthread_exit(&thrds[0]);
		goto out;
	}

	pthread_join(thrds[1], &ret);
	pthread_join(thrds[0], &ret);

	if (skip) {
		test__skip();
		goto out;
	}

	if (*timer1_err != -EDEADLK && *timer1_err != 0)
		ASSERT_FAIL("timer1_err bad value");
	if (*timer2_err != -EDEADLK && *timer2_err != 0)
		ASSERT_FAIL("timer2_err bad value");
out:
	timer_lockup__destroy(skel);
	return;
}