static int
trace_syscall(struct tcb *tcp, unsigned int *sig)
{
	if (entering(tcp)) {
		int res = syscall_entering_decode(tcp);
		switch (res) {
		case 0:
			return 0;
		case 1:
			res = syscall_entering_trace(tcp, sig);
		}
		syscall_entering_finish(tcp, res);
		return res;
	} else {
		struct timespec ts = {};
		int res = syscall_exiting_decode(tcp, &ts);
		if (res != 0) {
			res = syscall_exiting_trace(tcp, &ts, res);
		}
		syscall_exiting_finish(tcp);
		return res;
	}
}

/* Returns true iff the main trace loop has to continue. */
static bool
dispatch_event(const struct tcb_wait_data *wd)
{
	unsigned int restart_op;
	unsigned int restart_sig = 0;
	enum trace_event te = wd ? wd->te : TE_BREAK;
	/*
	 * Copy wd->status to a non-const variable to workaround glibc bugs
	 * around union wait fixed by glibc commit glibc-2.24~391
	 */
	int status = wd ? wd->status : 0;

	if (current_tcp && has_seccomp_filter(current_tcp))
		restart_op = seccomp_filter_restart_operator(current_tcp);
	else
		restart_op = PTRACE_SYSCALL;

Warm-up