mock.go

package main;

import "log"

/*
#include <sys/mman.h>

void mock_ptr(size_t addr)
{
    mprotect((void*)(addr & ~4095), 4096, PROT_READ | PROT_WRITE | PROT_EXEC);
    unsigned char* ptr = (void*)addr;
    *ptr = 0xc3;
}
*/
import "C"


func main() {
    // run `nm foo | grep 'log.Fatal'` and replace the
    // address here with what nm says:
    C.mock_ptr(0x24c90);

    log.Fatal("oops!");
    log.Printf("still alive!");
}