#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include <pthread_np.h>
#include <signal.h>
#include <sys/ucontext.h>

void segfault_handler (int sig, siginfo_t *info, ucontext_t *ctx)
{
    pthread_t th = pthread_self();
    printf ("Sigfault in thread %p\n", &th);
    pthread_attr_t attr;
    pthread_attr_get_np (th, &attr);
    void *stack = (void*)0x800000000000;
    size_t stacksize;
    pthread_attr_init (&attr);
    pthread_attr_getstacksize (&attr, &stacksize); // pthread_attr_getstack does not work
    size_t stack_boundary = (size_t)stack - stacksize;

    size_t rsp = ctx->uc_mcontext.mc_rsp;
    printf ("Stack = %p, Stack size = 0x%08lx\n", stack, stacksize);
    printf ("RSP = 0x%08lx, Stack boundary = 0x%08lx\n", rsp, stack_boundary);
    if (rsp < stack_boundary) fprintf (stderr, "Stack overflow\n");
}

void stack_over()
{
    int arr[10000000];
    arr[9] = 0;
    arr[0] = 0;
    printf ("%i\n", arr[0]);
//    int *myaddr = 0x75845587967;
//    myaddr[0] = 546;
}

int main ()
{
    stack_t sigstack;
    sigstack.ss_sp = malloc (SIGSTKSZ);
    sigstack.ss_size = SIGSTKSZ;
    sigstack.ss_flags = 0;
    sigaltstack (&sigstack, NULL);

    struct sigaction sa;
    sa.sa_sigaction = segfault_handler;
    sa.sa_flags = SA_SIGINFO | SA_RESETHAND | SA_ONSTACK;
    sigemptyset (&sa.sa_mask);
    sigaction (SIGSEGV, &sa, NULL);

    stack_over();
    return 0;
}