Don't report file descriptors as "leaked" if they were already open

This is necessary to run the regression tests under valgrind (if
telling it to output to a dedicated fd), gdb, fakeroot etc.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=35173
Reviewed-by: Colin Walters <walters@verbum.org>

bus/test-main.c

@@ -54,6 +54,8 @@ check_memleaks (const char *name)
 }
 #endif /* DBUS_BUILD_TESTS */
 
+static DBusInitialFDs *initial_fds = NULL;
+
 static void
 test_pre_hook (void)
 {
@@ -62,16 +64,21 @@ test_pre_hook (void)
       && (!bus_selinux_pre_init ()
 	  || !bus_selinux_full_init ()))
     die ("could not init selinux support");
+
+  initial_fds = _dbus_check_fdleaks_enter ();
 }
 
 static char *progname = "";
+
 static void
 test_post_hook (void)
 {
   if (_dbus_getenv ("DBUS_TEST_SELINUX"))
     bus_selinux_shutdown ();
   check_memleaks (progname);
-  _dbus_check_fdleaks();
+
+  _dbus_check_fdleaks_leave (initial_fds);
+  initial_fds = NULL;
 }
 
 int

dbus/dbus-message-private.h

@@ -138,8 +138,9 @@ dbus_bool_t _dbus_message_iter_get_args_valist (DBusMessageIter *iter,
                                                 int              first_arg_type,
                                                 va_list          var_args);
 
-
-void _dbus_check_fdleaks(void);
+typedef struct DBusInitialFDs DBusInitialFDs;
+DBusInitialFDs *_dbus_check_fdleaks_enter (void);
+void            _dbus_check_fdleaks_leave (DBusInitialFDs *fds);
 
 /** @} */
 

dbus/dbus-message-util.c

@@ -138,12 +138,66 @@ check_memleaks (void)
     }
 }
 
-void
-_dbus_check_fdleaks(void)
-{
-
 #ifdef __linux__
+struct DBusInitialFDs {
+    fd_set set;
+};
+#endif
 
+DBusInitialFDs *
+_dbus_check_fdleaks_enter (void)
+{
+#ifdef __linux__
+  DIR *d;
+  DBusInitialFDs *fds;
+
+  /* this is plain malloc so it won't interfere with leak checking */
+  fds = malloc (sizeof (DBusInitialFDs));
+  _dbus_assert (fds != NULL);
+
+  /* This works on Linux only */
+
+  if ((d = opendir("/proc/self/fd")))
+    {
+      struct dirent *de;
+
+      while ((de = readdir(d)))
+        {
+          long l;
+          char *e = NULL;
+          int fd;
+
+          if (de->d_name[0] == '.')
+            continue;
+
+          errno = 0;
+          l = strtol(de->d_name, &e, 10);
+          _dbus_assert(errno == 0 && e && !*e);
+
+          fd = (int) l;
+
+          if (fd < 3)
+            continue;
+
+          if (fd == dirfd(d))
+            continue;
+
+          FD_SET (fd, &fds->set);
+        }
+
+      closedir(d);
+    }
+
+  return fds;
+#else
+  return NULL;
+#endif
+}
+
+void
+_dbus_check_fdleaks_leave (DBusInitialFDs *fds)
+{
+#ifdef __linux__
   DIR *d;
 
   /* This works on Linux only */
@@ -173,12 +227,19 @@ _dbus_check_fdleaks(void)
           if (fd == dirfd(d))
             continue;
 
+          if (FD_ISSET (fd, &fds->set))
+            continue;
+
           _dbus_warn("file descriptor %i leaked in %s.\n", fd, __FILE__);
           _dbus_assert_not_reached("fdleaks");
         }
 
       closedir(d);
     }
+
+  free (fds);
+#else
+  _dbus_assert (fds == NULL);
 #endif
 }
 
@@ -1000,6 +1061,9 @@ _dbus_message_test (const char *test_data_dir)
   int v_UNIX_FD;
 #endif
   char **decomposed;
+  DBusInitialFDs *initial_fds;
+
+  initial_fds = _dbus_check_fdleaks_enter ();
 
   message = dbus_message_new_method_call ("org.freedesktop.DBus.TestService",
                                           "/org/freedesktop/TestPath",
@@ -1394,7 +1458,8 @@ _dbus_message_test (const char *test_data_dir)
   _dbus_message_loader_unref (loader);
 
   check_memleaks ();
-  _dbus_check_fdleaks();
+  _dbus_check_fdleaks_leave (initial_fds);
+  initial_fds = _dbus_check_fdleaks_enter ();
 
   /* Check that we can abandon a container */
   message = dbus_message_new_method_call ("org.freedesktop.DBus.TestService",
@@ -1458,16 +1523,23 @@ _dbus_message_test (const char *test_data_dir)
   }
 
   check_memleaks ();
-  _dbus_check_fdleaks();
+  _dbus_check_fdleaks_leave (initial_fds);
 
   /* Now load every message in test_data_dir if we have one */
   if (test_data_dir == NULL)
     return TRUE;
 
-  return dbus_internal_do_not_use_foreach_message_file (test_data_dir,
+  initial_fds = _dbus_check_fdleaks_enter ();
+
+  if (!dbus_internal_do_not_use_foreach_message_file (test_data_dir,
                                                         (DBusForeachMessageFileFunc)
                                                         dbus_internal_do_not_use_try_message_file,
-                                                        NULL);  
+                                                        NULL))
+    _dbus_assert_not_reached ("foreach_message_file test failed");
+
+  _dbus_check_fdleaks_leave (initial_fds);
+
+  return TRUE;
 }
 
 #endif /* DBUS_BUILD_TESTS */