链栈。为何输出结果完全不符合预期？？

#include<stdio.h>
#include<stdlib.h>
typedef int SElemType;
typedef struct StackNode
{
    SElemType data;
    struct StackNode *next;
}StackNode,*LinkStackPtr;
typedef struct 
{
    LinkStackPtr top;
    int count;
}LinkStack;
#define ERROR 0
#define OKAY 1
typedef int Status;
Status InitStack(LinkStack *S) 
{
    S->top = NULL; 
    S->count = 0;  
    return OKAY;
}
Status Push(LinkStack *S,SElemType e)
{
    LinkStackPtr m=(LinkStackPtr)malloc(sizeof(StackNode));
    m->data = e;
    m->next = S->top;
    S->top = m;
    S->count++;
    return OKAY;
}
Status StackEmpty(LinkStack S)  
{
    if(S.top == NULL)
    	return ERROR;
    return OKAY;
}
Status Pop(LinkStack *S,SElemType *e)
{
    if(StackEmpty(*S)) 
        return ERROR;
    LinkStackPtr p;
    *e = S->top->data; 
    p = S->top;
    S->top = S->top->next;
    free(p);
    p = NULL;  
    S->count--; 
    return OKAY;
}
int main()
{
    LinkStack S;
    InitStack(&S);
    Push(&S,1);
    Push(&S,2);
    Push(&S,3);
    Push(&S,4);
    Push(&S,5);
    SElemType e1,e2;
    Pop(&S,&e1);
    Pop(&S,&e2);
    printf("%d\n%d\n",e1,e2);
    for(LinkStackPtr p = S.top;p;p=p->next)
    {
        printf("%d ",p->data);
    }
    return 0;
}