#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#define TRAP_FLAG 0x100
# define ENTER_KERNEL   "int $0x80\n\t"
#define STACK_LIMIT	90000
#define HEAP_LIMIT	0x200000

void test_libfunction(const char *ori)
{
   int result;

/* set probepoint at strcmp function, when program is
 * loaded to run, it will load first few page into page,
 * and then load page on demand
 */	
	result = strcmp(ori,"1234");	
}

void test_stack(){
   int i;
   int p[STACK_LIMIT];

/* set user probepoint here, and default there will
 * be do_page_fault handler to expand stack
 */
	p[0]=0;	
	i=0;
	i++;
}

void test_heap(){
   char *pchar;
	
	pchar = (char*) malloc(HEAP_LIMIT);
	pchar += (HEAP_LIMIT - 1); 
	*pchar = 'c';  //set probe point here

}

int test_dummy(int i)
{
	return i+1;
}

void test_functioncall()
{
    int i;
	i=0;
/* set probepoint at function call point */
	test_dummy(i);	
}

void test_functionreturn()
{
   int i;
	i=0;
/* set probepoint at function return point */
	return;	
}

void test_trap3()
{
/* set probepoint at here */	
	asm volatile (".byte 0xcc");
}

void test_syscall()
{
/* set probepoint at int 0x80 point */
	asm volatile (ENTER_KERNEL : : "a" (20) /* getpid() */);
}

void my_trap(int sig)
{
  printf("trap1 : PASS\n");
}

void test_fork(){
   int pid, status;
   char *pchar;

	pchar = (char*) malloc(HEAP_LIMIT);
	pchar += (HEAP_LIMIT - 1);
	pid= fork();
	if (pid == 0){
	/* here it will generate COW, and set probepoint here */
		*pchar = 'c';
		exit(0);
	}
	else{
		wait(&status);
	}
   
}

int main()
{
  int result,pid;
  int status;
  int i;
  char *pchar;

  	signal(SIGTRAP, my_trap);

/* set probepoint at i=i+1 point */
  	i=i+1;
	pchar = "12345";
	test_libfunction(pchar);

	test_stack();

	test_heap();

	test_functioncall();

	test_functionreturn();

	test_trap3();

	test_syscall();
	
	test_fork();	
	printf("finished\n");
	return 0;
}