ptrace_test

ptrace_test.c

#include <iostream>
#include <unistd.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/signal.h>
#include <sys/ptrace.h>

volatile int g_running = 1;

int main() {
  setbuf(stdout, 0);
  setbuf(stderr, 0);

  printf("START APPLICATION (pid=%d)\n", ::getpid());
  int forked = fork();
  if (forked > 0) {
    printf("[PARENT] I am parent (pid=%d, child=%d)\n", getpid(), forked);

    long ptrace_res = ptrace(PTRACE_ATTACH, forked, 0, 0);
    printf("[PARENT] PTRACE_ATTACH ptrace_res = %d\n", ptrace_res);

//    ptrace_res = ptrace(PTRACE_SETOPTIONS, forked, NULL, PTRACE_O_TRACEEXIT);
//    printf("[PARENT] PTRACE_SETOPTIONS ptrace_res = %d\n", ptrace_res);
    pid_t signaled_pid;
    int signaled_stat = 0;

    // WNOHANG
    while((signaled_pid = ::waitpid(-1, &signaled_stat, 0)) >= 0) {
      char temp[128];

      printf("[PARENT, %d] wait result : %d / %d\n", signaled_pid, signaled_stat);

      struct stat st = { 0 };
      sprintf(temp, "/proc/%d", signaled_pid);
      if (stat(temp, &st) == -1 && errno == ENOENT) {
        printf("CHILD IS DEAD!\n");
      }

      if(WIFEXITED(signaled_stat)) {
        printf("[PARENT, %d] WIFEXITED exit_status=%d\n", signaled_pid, WEXITSTATUS(signaled_stat));
      }
      if (WIFSIGNALED(signaled_stat)) {
        printf("[PARENT, %d] WIFSIGNALED signal=%d\n", signaled_pid, WTERMSIG(signaled_stat));
      }
      if (WIFSTOPPED(signaled_stat)) {
        printf("[PARENT, %d] WIFSTOPPED signal=%d\n", signaled_pid, WSTOPSIG(signaled_stat));
        if (WSTOPSIG(signaled_stat) == SIGSEGV) {
          printf("CHILD IS SIGSEGV!!!\n");


          while (1) {
            if (stat(temp, &st) == -1 && errno == ENOENT) {
              printf("CHILD IS DEAD!\n");
            } else {
              printf("CHILD IS ALIVE!\n");
            }
            usleep(1000000);
          }
        }
      }

      if (WIFCONTINUED(signaled_stat)) {
        printf("[PARENT, %d] WIFCONTINUED\n", signaled_pid);
      }
      if (ptrace(PTRACE_CONT, forked, 0, WSTOPSIG(signaled_stat))) {
        printf("stopper: ptrace(PTRACE_CONT, ...)");
        break;
      }
    }
    printf("** FINISH WAIT! / %d\n", signaled_pid);

//    ptrace_res = ptrace(PT_KILL, forked, 0, 0);
//    printf("[PARENT] PTRACE_O_TRACEEXIT ptrace_res = %d\n", ptrace_res);

    while(g_running) {
      usleep(1000000);
    }
  } else if (forked == 0) {
    printf("[CHILD] TP-2\n");
    usleep(1000000);
    printf("[CHILD] TP-3\n");
    printf("[CHILD] I am borned (pid=%d, ppid=%d)\n", getpid(), getppid());
    *((int*)0x1234) = 0x12345678;
    return 123;
  } else {
    printf("ERROR\n");
  }

  printf("APP EXIT forked=%d\n", forked);

  return 0;
}