Add/uncomment to ///etc/security/limits.conf//
<code bash>
*       soft    core    unlimited
*       hard    core    unlimited
root       soft    core    unlimited
root       hard    core    unlimited
</code>

Add to ///etc/sysctl.conf//
<code bash>
kernel.core_pattern = /var/coredumps/core-%e-%s-%u-%g-%p-%t
kernel.core_uses_pid = 1
fs.suid_dumpable = 2
</code>

Create ///var/coredumps///

Edit ///etc/systemd/system.conf//
<code bash>
DefaultLimitCORE=infinity
</code>

Run
<code bash>
sysctl -p
ulimit -c unlimited
systemctl daemon-reexec
</code>

Restart all needed services

For testing create file //test.c//
<code bash>
int a (int *p) {
    int y = *p;
    return y;
}
     
int main (void) {
    int *p = 0; /* null pointer */
    return a (p);
}
</code>

Compile and run
<code bash>
gcc -o test test.c && ./test
</code>