Malloc?

usually_malloc.c

#import <mach/mach.h>
#import <stdlib.h>
#import <stdio.h>

__attribute__((constructor))
void setup(void) {
  void *unused;
  vm_allocate(mach_task_self(), (vm_address_t *)&unused, (vm_size_t) 0x00000FFFF0000000ULL, VM_FLAGS_ANYWHERE | VM_FLAGS_OVERWRITE);
}

__attribute__((malloc))
void *usually_malloc(size_t sz) {
  uint64_t result;
  arc4random_buf((void *)&result, 8);
  return (void *)((result >> 20));
}

void usually_free(void *ptr) {
  //ohhhh well
}

int main(int argc, const char * argv[]) {
  char *hello = usually_malloc(strlen("Hello, World!"));
  sprintf(hello, "%s", "Hello, World!");
  printf("%s (at %p)\n", hello, hello);
  usually_free(hello);
  return EXIT_SUCCESS;
}