#include <stdio.h>
#include <signal.h>
#include <sys/wait.h>
void hup_handle() {
    kill(getpid(), SIGINT);
    return;
}
int main(void) {
    pid_t pid, work = 0;
    int ret;
    do {
        pid = fork();
        if (pid == 0) {
            signal(SIGHUP, hup_handle);
            
            while (1) {
                sleep(5);
            }
        } else if (pid < 0) {
            return (-1);
        } else {
            signal(SIGHUP, SIG_IGN);
            waitpid(pid, &ret, WUNTRACED);
            if (!WIFEXITED(ret))
                work = 1; 
            else if (WIFSIGNALED(ret)) 
                work = 0;
            else if (WIFSTOPPED(ret))
                work = 1;
        }
    } while (work > 0);
    return (0);
}

Где косяк? :)