#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
//#include <asm/ptrace.h>
#include <asm/ptrace_offsets.h>

char *prog_name;

/* this is entry address in kernel gate page for break syscall 
 * this macro need be changed with kernel
 */
#define __kernel_syscall_via_break 0xa000000000010620UL

/* here is syscall_via_break code in kernel side, break instruction
 * is the first slot of the bundle
 * GLOBAL_ENTRY(__kernel_syscall_via_break)
 * { .mib
 *       break 0x100000
 *       nop.i 0
 *       br.ret.sptk.many b6
 *}
*/
static int singlestep_slot1, singlestep_slot2;
void print_instruction (int child_pid, int state)
{
	long ip, slot;
	unsigned long psr;

	ip = ptrace (PTRACE_PEEKUSER, child_pid, PT_CR_IIP, 0);
	psr = ptrace(PTRACE_PEEKUSER, child_pid, PT_CR_IPSR, 0);
	slot = (psr >> 41) & 0x3;
	if (ip == __kernel_syscall_via_break) {
		if (slot == 1)
			singlestep_slot1++;
		else if (slot == 2)
			singlestep_slot2++;
	} 
}

int main (int argc, char **argv, char **envp)
{
	int status, pid, child_pid, state = 1, arg = 1;
	int ret;

	singlestep_slot1 = singlestep_slot2 = 0;
	prog_name = argv[0];

	child_pid = fork ();
	if (child_pid == 0)
	{
		ptrace (PTRACE_TRACEME, 0, 0, 0);
		execve (argv[arg], argv + arg, envp);
		printf ("%s: execve failed (errno=%d)\n", prog_name, errno);
		exit(-2);
	}

	while (1)
	{
		pid = wait4 (-1, &status, 0, 0);
		if (pid == -1)
		{
			if (errno == EINTR)
				continue;

			printf ("%s: wait4() failed (errno=%d)\n", prog_name, errno);
		}
		if (WIFSIGNALED (status) || WIFEXITED (status)
				|| (WIFSTOPPED (status) && WSTOPSIG (status) != SIGTRAP))
		{
			if (WIFEXITED (status))
			{
				printf ("%s: exit status %d\n", prog_name, WEXITSTATUS (status));
				break;
			}
			else if (WIFSIGNALED (status))
			{
				printf ("%s: terminated by signal %d\n",
						prog_name, WTERMSIG (status));
			}
			else {
				printf ("%s: got signal %d\n", prog_name, WSTOPSIG (status));
			}
		}
		print_instruction (child_pid, state);
		ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0);
	}
	if (WEXITSTATUS (status) == 0) {
		if (singlestep_slot1 == 0)
			printf("single step on syscall failed\n");
		else {
			printf("single step on syscall succeed\n");
			printf("single step on break bundle slot 0: %d slot 1: %d \n",
					singlestep_slot1, singlestep_slot2);
		}
	}
	return 0;
}