pthread memory leaks

I'm experimenting with signals and conditional variables to implement
thread suspension. The following appears to execute without any
problems but valgrind reports memory leaks.
What can I do to stop the memory leaks? Is there some type of pthread
related memory free function I'm forgetting?

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#include <pthread.h>
#include <signal.h>
#include <unistd.h>
#include <cstdio>
#include <cstring>
#include <cstdlib>

pthread_mutex_t m;
pthread_cond_t c;

void freeze(int sig) {
        pthread_mutex_lock(&m);
        pthread_cond_wait(&c, &m);
        pthread_mutex_unlock(&m);
}
void quit(int sig) { pthread_exit(0); }

void* tfunc(void* param) {
    while (1) {
        puts("hi");
        sleep(1);
    }
    return NULL;
}

int main() {
    pthread_mutex_init(&m, NULL);
    pthread_cond_init(&c, NULL);
    struct sigaction s;
    memset(&s, 0, sizeof(struct sigaction));

    /*
    * SIGUSR1 signal for thread suspend
    * and SIGUSR2 signal for thread exit
    */
    s.sa_handler = &freeze;
    s.sa_flags = SA_SIGINFO;
    sigaction(SIGUSR1, &s, NULL);
    s.sa_handler = &quit;
    sigaction(SIGUSR2, &s, NULL);

    pthread_t t;
    pthread_create(&t, NULL, &tfunc, (void*)NULL);
    pthread_detach(t);
    getchar();
    /* suspend */
    pthread_kill(t, SIGUSR1);
    getchar();
    /* resume */
    pthread_cond_signal(&c);
    getchar();
    /* terminate */
    pthread_kill(t, SIGUSR2);
    pthread_mutex_destroy(&m);
    pthread_cond_destroy(&c);
    return 0;
}
=================================

valgrind output:
=================================
==2993==
==2993== HEAP SUMMARY:
==2993== in use at exit: 144 bytes in 1 blocks
==2993== total heap usage: 1 allocs, 0 frees, 144 bytes allocated
==2993==
==2993== LEAK SUMMARY:
==2993== definitely lost: 0 bytes in 0 blocks
==2993== indirectly lost: 0 bytes in 0 blocks
==2993== possibly lost: 144 bytes in 1 blocks
==2993== still reachable: 0 bytes in 0 blocks
==2993== suppressed: 0 bytes in 0 blocks
==2993== Rerun with --leak-check=full to see details of leaked memory
==2993==
==2993== For counts of detected and suppressed errors, rerun with: -v
==2993== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 21 from
8)
=================================