Stack implementation is giving Segfault - c

Question

I am currently writing my own virtual machine. I have to implement the stack. For whatever reason whenever I call sienna_stack_push(processor->stack, 0); it gives me a segfault.
here is the implementation of the stack
#include <stdlib.h>
#include <stdio.h>
#include "stack.h"
// Helper functions
int is_empty(sienna_stack_t* stack){
return stack->top == -1;
}
int is_full(sienna_stack_t* stack){
return stack->top == stack->max_size;
}
void sienna_stack_init(sienna_stack_t* stack, int capacity){
stack = (sienna_stack_t*)malloc(sizeof(sienna_stack_t));
stack->max_size = capacity;
stack->top = -1;
stack->items = (int*)calloc(capacity, sizeof(int));
}
void sienna_stack_push(sienna_stack_t* stack, int value){
if(is_full(stack)){
printf("FATAL: Stack overflow!\n");
exit(-1);
}
stack->items[++stack->top] = value;
}
int sienna_stack_pop(sienna_stack_t* stack){
if(is_empty(stack)){
printf("FATAL: Stack underflow!\n");
exit(-1);
}
return stack->items[stack->top--];
}
int sienna_stack_peek(sienna_stack_t* stack){
return stack->items[stack->top];
}
here is the stack struct definition
typedef struct {
int max_size;
int top;
int* items;
} sienna_stack_t;
here is me using it
#include <stdio.h>
#include "stack.h"
int main() {
sienna_stack_t stack;
sienna_stack_init(&stack, 0xFFFF);
sienna_stack_push(&stack, 0);
}
and the error is saying it is happening when calling sienna_stack_push();

Answer 1

I guess, you want to reserve sizeof(int) * capacity bytes of memory, but in reality you reserve nothing, because the first parameter of calloc() is 0. Thus, you want to access non-reserved memory, that leads to a crash.
EDIT
Your initialisation is wrong. stack is a static variable. When you call init, you pass the address of this variable. Now you assign an new (anonymous) variable that get lost. You could change stack into a pointer variable:
void sienna_stack_init(sienna_stack_t** stack, int capacity){
*stack = (sienna_stack_t*)malloc(sizeof(sienna_stack_t));
(*stack)->max_size = capacity;
(*stack)->top = -1;
(*stack)->items = (int*)calloc(capacity, sizeof(int));
}
// ...
int main(int argc, char *argv[]){
sienna_stack_t *stack;
sienna_stack_init(&stack, 0xFFF);
sienna_stack_push(stack, 0);
}