Add ExceptionPorts and its test

util/mach/exception_ports.cc

+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "util/mach/exception_ports.h"
+
+#include "base/logging.h"
+#include "base/mac/mach_logging.h"
+
+namespace crashpad {
+
+ExceptionPorts::ExceptionPorts(TargetType target_type, mach_port_t target_port)
+    : target_port_(target_port), dealloc_target_port_(false) {
+  switch (target_type) {
+    case kTargetTypeHost:
+      get_exception_ports_ = host_get_exception_ports;
+      set_exception_ports_ = host_set_exception_ports;
+      target_name_ = "host";
+      if (target_port_ == MACH_PORT_NULL) {
+        target_port_ = mach_host_self();
+        dealloc_target_port_ = true;
+      }
+      break;
+
+    case kTargetTypeTask:
+      get_exception_ports_ = task_get_exception_ports;
+      set_exception_ports_ = task_set_exception_ports;
+      target_name_ = "task";
+      if (target_port_ == MACH_PORT_NULL) {
+        target_port_ = mach_task_self();
+        // Don’t deallocate mach_task_self().
+      }
+      break;
+
+    case kTargetTypeThread:
+      get_exception_ports_ = thread_get_exception_ports;
+      set_exception_ports_ = thread_set_exception_ports;
+      target_name_ = "thread";
+      if (target_port_ == MACH_PORT_NULL) {
+        target_port_ = mach_thread_self();
+        dealloc_target_port_ = true;
+      }
+      break;
+
+    default:
+      NOTREACHED();
+      get_exception_ports_ = NULL;
+      set_exception_ports_ = NULL;
+      target_name_ = NULL;
+      target_port_ = MACH_PORT_NULL;
+      break;
+  }
+}
+
+ExceptionPorts::~ExceptionPorts() {
+  if (dealloc_target_port_) {
+    kern_return_t kr = mach_port_deallocate(mach_task_self(), target_port_);
+    MACH_LOG_IF(ERROR, kr != KERN_SUCCESS, kr) << "mach_port_deallocate";
+  }
+}
+
+bool ExceptionPorts::GetExceptionPorts(
+    exception_mask_t mask,
+    std::vector<ExceptionHandler>* handlers) const {
+  // <mach/mach_types.defs> says that these arrays have room for 32 elements,
+  // despite EXC_TYPES_COUNT only being as low as 11 (in the 10.6 SDK), and
+  // later operating system versions have defined more exception types. The
+  // generated task_get_exception_ports() in taskUser.c expects there to be room
+  // for 32.
+  const int kMaxPorts = 32;
+
+  // task_get_exception_ports() doesn’t actually use the initial value of
+  // handler_count, but 10.9.4
+  // xnu-2422.110.17/osfmk/man/task_get_exception_ports.html says it does. Humor
+  // the documentation.
+  mach_msg_type_number_t handler_count = kMaxPorts;
+
+  exception_mask_t masks[kMaxPorts];
+  exception_handler_t ports[kMaxPorts];
+  exception_behavior_t behaviors[kMaxPorts];
+  thread_state_flavor_t flavors[kMaxPorts];
+
+  kern_return_t kr = get_exception_ports_(
+      target_port_, mask, masks, &handler_count, ports, behaviors, flavors);
+  if (kr != KERN_SUCCESS) {
+    MACH_LOG(ERROR, kr) << TargetTypeName() << "_get_exception_ports";
+    return false;
+  }
+
+  handlers->clear();
+  for (mach_msg_type_number_t index = 0; index < handler_count; ++index) {
+    ExceptionHandler handler;
+    handler.mask = masks[index];
+    handler.port = ports[index];
+    handler.behavior = behaviors[index];
+    handler.flavor = flavors[index];
+    handlers->push_back(handler);
+  }
+
+  return true;
+}
+
+bool ExceptionPorts::SetExceptionPort(exception_mask_t mask,
+                                      exception_handler_t port,
+                                      exception_behavior_t behavior,
+                                      thread_state_flavor_t flavor) const {
+  kern_return_t kr =
+      set_exception_ports_(target_port_, mask, port, behavior, flavor);
+  if (kr != KERN_SUCCESS) {
+    MACH_LOG(ERROR, kr) << TargetTypeName() << "_set_exception_ports";
+    return false;
+  }
+
+  return true;
+}
+
+const char* ExceptionPorts::TargetTypeName() const {
+  return target_name_;
+}
+
+}  // namespace crashpad