Stack using linked list

#include <stdio.h>
#include <malloc.h>
struct node{
    int data;
    struct node *next;
}*top=NULL;

void push(int);
void pop();
void dis();
int main()
{
    int ch,t;
    while(1){
        printf("\n");
        printf("1:PUSH\n");
        printf("2:POP\n");
        printf("3:DISPLAY\n");
        printf("4:EXIT\n");
        printf("Enter option\n");
        scanf("%d",&ch);
        switch (ch)
        {
            case 1: {
                printf("enter data:");
                scanf("%d", &t);
                push(t);
                continue;
            }
            case 2:{
                pop();
                continue;
            }
            case 3:{
                dis();
                continue;
            }
            case 4:{
                return 0;
            }
        }
    }
    return 0;
}
void push(int n)
{
    struct node *newnode = (struct node*)malloc(sizeof(struct node));
    newnode->data = n;
    if(top==NULL)
    {
        newnode->next=NULL;
    }
    else{
        newnode->next=top;
    }
    top = newnode;
}

void pop(){
    if(top==NULL)
        printf("STACK Underflow: stack is empty.....");
    else{
        struct node *temp = top;
        printf("value deleted %d", temp->data);
        top=top->next;
        free(temp);
    }
}

void dis() {
    if (top == NULL) {
        printf("No data found in stack!!!!");
    } else {
        struct node *temp = top;
        while (temp != NULL) {
            printf("<--%d\t", temp->data);
            temp = temp->next;
        }
    }
}