AOS HW2 test our system call

syscall_test.c

#include <stdio.h>
#include <linux/kernel.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>

#include "dummysyscall.h"

void print_prinfo(prinfo_t *prinfo)
{
  fprintf(stderr, "uid = %ld run program %s\n",
      prinfo->uid, prinfo->comm);
  fprintf(stderr, "pid = %d in state %ld with nice value = %ld\n",
      prinfo->pid, prinfo->state, prinfo->nice);
  fprintf(stderr, "parent %d -> current %d\n", prinfo->parent_pid, prinfo->pid);
  fprintf(stderr, "youngest child %d, younger_sibling_pid %d, older_sibling_pid %d\n",
      prinfo->youngest_child_pid, prinfo->younger_sibling_pid, prinfo->older_sibling_pid);
  fprintf(stderr, "process started at %ld\n", prinfo->start_time);
  fprintf(stderr, "time: user %ld, sys %ld, cutime %ld, cstime %ld\n",
      prinfo->user_time, prinfo->sys_time, prinfo->cutime, prinfo->cstime);
}

int main()
{
  prinfo_t *p_prinfo = (prinfo_t *)malloc(sizeof(prinfo_t));
  memset(p_prinfo, 0, sizeof(prinfo_t));

  printf("Invoking 'dummy syscall' system call\n");
  printf("====================================\n");
  
  // Run for a while so that we have time in utime/stime
  unsigned int sum = 0;
  for (int i = 0; i < 100000000; ++i) {
    sum += i;
  }

  pid_t pid;

  // Create a child so we have child process.
  if ((pid = fork()) == 0) {
    sleep(10);
  } else {
    long ret_status = syscall(330, p_prinfo); // 330 for dummy system call

    if (ret_status != 0) {
      printf("System call 'dummy syscall' did not execute as expected\n");
      return ret_status;
    }

    print_prinfo(p_prinfo);

    wait(NULL);

    return 0;
  }
}