lldb/test/API/commands/process/attach/attach_denied/main.cpp

   1 #include <errno.h>
   2 #include <fcntl.h>
   3 #include <signal.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8
   9 #include <sys/types.h>
  10 #include <sys/ptrace.h>
  11 #include <sys/stat.h>
  12 #include <sys/wait.h>
  13
  14 #if defined(PTRACE_ATTACH)
  15 #define ATTACH_REQUEST PTRACE_ATTACH
  16 #define DETACH_REQUEST PTRACE_DETACH
  17 #elif defined(PT_ATTACH)
  18 #define ATTACH_REQUEST PT_ATTACH
  19 #define DETACH_REQUEST PT_DETACH
  20 #else
  21 #error "Unsupported platform"
  22 #endif
  23
  24 bool writePid (const char* file_name, const pid_t pid)
  25 {
  26     char *tmp_file_name = (char *)malloc(strlen(file_name) + 16);
  27     strcpy(tmp_file_name, file_name);
  28     strcat(tmp_file_name, "_tmp");
  29     int fd = open (tmp_file_name, O_CREAT | O_WRONLY | O_TRUNC, S_IRUSR | S_IWUSR);
  30     if (fd == -1)
  31     {
  32         fprintf (stderr, "open(%s) failed: %s\n", tmp_file_name, strerror (errno));
  33         free(tmp_file_name);
  34         return false;
  35     }
  36     char buffer[64];
  37     snprintf (buffer, sizeof(buffer), "%ld", (long)pid);
  38
  39     bool res = true;
  40     if (write (fd, buffer, strlen (buffer)) == -1)
  41     {
  42         fprintf (stderr, "write(%s) failed: %s\n", buffer, strerror (errno));
  43         res = false;
  44     }
  45     close (fd);
  46
  47     if (rename (tmp_file_name, file_name) == -1)
  48     {
  49         fprintf (stderr, "rename(%s, %s) failed: %s\n", tmp_file_name, file_name, strerror (errno));
  50         res = false;
  51     }
  52     free(tmp_file_name);
  53
  54     return res;
  55 }
  56
  57 void signal_handler (int)
  58 {
  59 }
  60
  61 int main (int argc, char const *argv[])
  62 {
  63     if (argc < 2)
  64     {
  65         fprintf (stderr, "invalid number of command line arguments\n");
  66         return 1;
  67     }
  68
  69     const pid_t pid = fork ();
  70     if (pid == -1)
  71     {
  72         fprintf (stderr, "fork failed: %s\n", strerror (errno));
  73         return 1;
  74     }
  75
  76     if (pid > 0)
  77     {
  78         // Make pause call to return when a signal is received. Normally this happens when the
  79         // test runner tries to terminate us.
  80         signal (SIGHUP, signal_handler);
  81         signal (SIGTERM, signal_handler);
  82         if (ptrace (ATTACH_REQUEST, pid, NULL, 0) == -1)
  83         {
  84             fprintf (stderr, "ptrace(ATTACH) failed: %s\n", strerror (errno));
  85         }
  86         else
  87         {
  88             if (writePid (argv[1], pid))
  89                 pause ();  // Waiting for the debugger trying attach to the child.
  90
  91             if (ptrace (DETACH_REQUEST, pid, NULL, 0) != 0)
  92                 fprintf (stderr, "ptrace(DETACH) failed: %s\n", strerror (errno));
  93         }
  94
  95         kill (pid, SIGTERM);
  96         int status = 0;
  97         if (waitpid (pid, &status, 0) == -1)
  98             fprintf (stderr, "waitpid failed: %s\n", strerror (errno));
  99     }
 100     else
 101     {
 102         // child inferior.
 103         pause ();
 104     }
 105
 106     printf ("Exiting now\n");
 107     return 0;
 108 }