Externally disabling signals for a Linux program

Question

On Linux, is it possible to somehow disable signaling for programs externally... that is, without modifying their source code?

Context:

Answer 1

This is example code of enabling signals like Ctrl+C for programs which block it.

fixControlC.c

#include 
#include 
int sigaddset(sigset_t *set, int signo) {
    printf("int sigaddset(sigset_t *set=%p, int signo=%d)\n", set, signo);
    return 0;
}

Compile it:

gcc -fPIC -shared -o fixControlC.so fixControlC.c

Run it:

LD_LIBRARY_PATH=. LD_PRELOAD=fixControlC.so mysqld