Perhaps you can compile and run this C program, before and after the system changes, and post the output:


#include <errno.h>
#include <signal.h>
#include <stdio.h>

int main(int argc, char** argv)
{
    sigset_t set;
    int i, ret;

    printf("NSIG = %d\n", NSIG);
    for (i = 1; i < NSIG; i++) {
        errno = 0;
        ret = sigaddset(&set, i);
        printf("sigaddset(%d) returned %d, errno =%d\n", i, ret, errno);
    }
    return 0;
}


(on Ubuntu 16.04, I get NSIG = 65, and all signal numbers work fine)