Add exc_client_variants (UniversalRaiseException()) and its test

util/mach/exc_client_variants_test.cc

Index: util/mach/exc_client_variants_test.cc
diff --git a/util/mach/exc_client_variants_test.cc b/util/mach/exc_client_variants_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..558ffb663bf06e25f9b96353bd52b706671711f7
--- /dev/null
+++ b/util/mach/exc_client_variants_test.cc
@@ -0,0 +1,288 @@
+// 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/exc_client_variants.h"
+
+#include <mach/mach.h>
+#include <pthread.h>
+#include <string.h>
+
+#include "base/basictypes.h"
+#include "base/strings/stringprintf.h"
+#include "gtest/gtest.h"
+#include "util/mach/exc_server_variants.h"
+#include "util/mach/mach_extensions.h"
+#include "util/test/mac/mach_errors.h"
+#include "util/test/mac/mach_multiprocess.h"
+
+namespace {
+
+using namespace crashpad;
+using namespace crashpad::test;
+
+class TestExcClientVariants : public UniversalMachExcServer,
+                              public MachMultiprocess {
+ public:
+  TestExcClientVariants(exception_behavior_t behavior, bool all_fields)
+      : UniversalMachExcServer(),
+        MachMultiprocess(),
+        behavior_(behavior),
+        all_fields_(all_fields),
+        handled_(false) {
+    ++exception_;
+    ++exception_code_;
+    ++exception_subcode_;
+  }
+
+  // UniversalMachExcServer:
+
+  virtual kern_return_t CatchMachException(
+      exception_behavior_t behavior,
+      exception_handler_t exception_port,
+      thread_t thread,
+      task_t task,
+      exception_type_t exception,
+      const mach_exception_data_type_t* code,
+      mach_msg_type_number_t code_count,
+      thread_state_flavor_t* flavor,
+      const natural_t* old_state,
+      mach_msg_type_number_t old_state_count,
+      thread_state_t new_state,
+      mach_msg_type_number_t* new_state_count,
+      bool* destroy_complex_request) override {
+    *destroy_complex_request = true;
+
+    EXPECT_FALSE(handled_);
+    handled_ = true;
+
+    EXPECT_EQ(behavior_, behavior);
+    EXPECT_EQ(LocalPort(), exception_port);
+
+    if (HasIdentity()) {
+      EXPECT_NE(kMachPortNull, thread);
+      EXPECT_EQ(ChildTask(), task);
+    } else {
+      EXPECT_EQ(kMachPortNull, thread);
+      EXPECT_EQ(kMachPortNull, task);
+    }
+
+    mach_exception_code_t expect_code = exception_code_;
+    mach_exception_subcode_t expect_subcode = exception_subcode_;
+    if ((behavior & MACH_EXCEPTION_CODES) == 0) {
+      expect_code = static_cast<exception_data_type_t>(expect_code);
+      expect_subcode = static_cast<exception_data_type_t>(expect_subcode);
+    }
+
+    EXPECT_EQ(exception_, exception);
+    EXPECT_EQ(2u, code_count);
+    EXPECT_EQ(expect_code, code[0]);
+    EXPECT_EQ(expect_subcode, code[1]);
+
+    if (HasState()) {
+      EXPECT_EQ(exception_ + 10, *flavor);
+      EXPECT_EQ(MACHINE_THREAD_STATE_COUNT, old_state_count);
+      EXPECT_NE(static_cast<const natural_t*>(NULL), old_state);
+      EXPECT_EQ(static_cast<mach_msg_type_number_t>(THREAD_STATE_MAX),
+                *new_state_count);
+      EXPECT_NE(static_cast<natural_t*>(NULL), new_state);
+
+      for (size_t index = 0; index < old_state_count; ++index) {
+        EXPECT_EQ(index, old_state[index]);
+      }
+
+      // Use a flavor known to be different from the incoming flavor, for a test
+      // of the “out” side of the inout flavor parameter.
+      *flavor = exception_ + 20;
+      *new_state_count = MACHINE_THREAD_STATE_COUNT;
+
+      // Send a new state back to the client.
+      for (size_t index = 0; index < *new_state_count; ++index) {
+        EXPECT_EQ(0u, new_state[index]);
+        new_state[index] = MACHINE_THREAD_STATE_COUNT - index;
+      }
+    } else {
+      EXPECT_EQ(THREAD_STATE_NONE, *flavor);
+      EXPECT_EQ(0u, old_state_count);
+      EXPECT_EQ(NULL, old_state);
+      EXPECT_EQ(0u, *new_state_count);
+      EXPECT_EQ(NULL, new_state);
+    }
+
+    return KERN_SUCCESS;
+  }
+
+ private:
+  // MachMultiprocess:
+
+  virtual void MachMultiprocessParent() override {
+    kern_return_t kr = MachMessageServer::Run(this,
+                                              LocalPort(),
+                                              MACH_MSG_OPTION_NONE,
+                                              MachMessageServer::kOneShot,
+                                              MachMessageServer::kBlocking,
+                                              0);
+    EXPECT_EQ(KERN_SUCCESS, kr)
+        << MachErrorMessage(kr, "MachMessageServer::Run");
+
+    EXPECT_TRUE(handled_);
+  }
+
+  virtual void MachMultiprocessChild() override {
+    exception_type_t exception = exception_;
+    mach_exception_data_type_t code[] = {

[Robert Sesek, 2014/09/15 20:55:43]

const?

+        exception_code_,
+        exception_subcode_
+    };
+
+    thread_t thread = MACH_PORT_NULL;
+    task_t task = MACH_PORT_NULL;
+    if (all_fields_ || HasIdentity()) {
+      thread = pthread_mach_thread_np(pthread_self());

[Robert Sesek, 2014/09/15 20:55:43]

Why do you do this instead of just mach_thread_self()?

+      task = mach_task_self();
+    }
+
+    thread_state_flavor_t flavor;
+    thread_state_flavor_t* flavor_p = NULL;
+    natural_t old_state[MACHINE_THREAD_STATE_COUNT];
+    thread_state_t old_state_p = NULL;
+    mach_msg_type_number_t old_state_count = 0;
+    natural_t new_state[THREAD_STATE_MAX];
+    thread_state_t new_state_p = NULL;
+    mach_msg_type_number_t new_state_count;
+    mach_msg_type_number_t* new_state_count_p = NULL;
+    if (all_fields_ || HasState()) {
+      // Pick a different flavor each time based on the value of exception_.
+      // These aren’t real flavors, it’s just for testing.
+      flavor = exception_ + 10;
+      flavor_p = &flavor;
+      for (size_t index = 0; index < arraysize(old_state); ++index) {
+        old_state[index] = index;
+      }
+      old_state_p = reinterpret_cast<thread_state_t>(&old_state);
+      old_state_count = arraysize(old_state);
+
+      // new_state and new_state_count are out parameters that the server should
+      // never see or use, so set them to bogus values. The call to the server
+      // should overwrite these.
+      memset(new_state, 0xa5, sizeof(new_state));
+      new_state_p = reinterpret_cast<thread_state_t>(&new_state);
+      new_state_count = 0x5a;
+      new_state_count_p = &new_state_count;
+    }
+
+    EXPECT_EQ(KERN_SUCCESS, UniversalExceptionRaise(behavior_,
+                                                    RemotePort(),
+                                                    thread,
+                                                    task,
+                                                    exception,
+                                                    code,
+                                                    arraysize(code),
+                                                    flavor_p,
+                                                    old_state_p,
+                                                    old_state_count,
+                                                    new_state_p,
+                                                    new_state_count_p));
+
+    if (HasState()) {
+      // Verify the out parameters.
+
+      EXPECT_EQ(exception_ + 20, flavor);
+      EXPECT_EQ(MACHINE_THREAD_STATE_COUNT, new_state_count);
+
+      for (size_t index = 0; index < new_state_count; ++index) {
+        EXPECT_EQ(MACHINE_THREAD_STATE_COUNT - index, new_state[index]);
+      }
+    }
+  }
+
+  exception_behavior_t BasicBehavior() const {
+    return behavior_ & ~MACH_EXCEPTION_CODES;
+  }
+
+  bool HasIdentity() const {
+    exception_behavior_t basic_behavior = BasicBehavior();
+    return basic_behavior == EXCEPTION_DEFAULT ||
+           basic_behavior == EXCEPTION_STATE_IDENTITY;
+  }
+
+  bool HasState() const {
+    exception_behavior_t basic_behavior = BasicBehavior();
+    return basic_behavior == EXCEPTION_STATE ||
+           basic_behavior == EXCEPTION_STATE_IDENTITY;
+  }
+
+  // The behavior to test.
+  exception_behavior_t behavior_;
+
+  // If false, only fields required for the current value of behavior_ are set
+  // in a call to UniversalExceptionRaise(). The thread and task fields are only
+  // set for identity-carrying behaviors, and the flavor and state fields are
+  // only set for state-carrying behaviors. If true, all fields are set
+  // regardless of the behavior. Testing in both ways verifies that
+  // UniversalExceptionRaise() can tolerate the null arguments documented as
+  // usable when the behavior allows it, and that it ignores these arguments
+  // even when set when the behavior does not make use of them.
+  bool all_fields_;
+
+  // true if an exception message was handled.
+  bool handled_;
+
+  // These fields will increment for each instantiation of the test class.
+  static exception_type_t exception_;
+  static mach_exception_code_t exception_code_;
+  static mach_exception_subcode_t exception_subcode_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestExcClientVariants);
+};
+
+exception_type_t TestExcClientVariants::exception_ = 0;
+
+// exception_code_ and exception_subcode_ are always large enough to require
+// 64 bits, so that when the 32-bit-only variants not using MACH_EXCEPITON_CODES
+// are tested, the code and subcode fields can be checked for proper truncation.
+mach_exception_code_t TestExcClientVariants::exception_code_ = 0x100000000;
+mach_exception_subcode_t TestExcClientVariants::exception_subcode_ =
+        0xffffffff00000000;
+
+TEST(ExcClientVariants, UniversalExceptionRaise) {
+  const exception_behavior_t kBehaviors[] = {
+      EXCEPTION_DEFAULT,
+      EXCEPTION_STATE,
+      EXCEPTION_STATE_IDENTITY,
+      kMachExceptionCodes | EXCEPTION_DEFAULT,
+      kMachExceptionCodes | EXCEPTION_STATE,
+      kMachExceptionCodes | EXCEPTION_STATE_IDENTITY,
+  };
+
+  for (size_t index = 0; index < arraysize(kBehaviors); ++index) {
+    exception_behavior_t behavior = kBehaviors[index];
+    SCOPED_TRACE(base::StringPrintf("index %zu, behavior %d", index, behavior));
+
+    {
+      SCOPED_TRACE("all_fields = false");
+
+      TestExcClientVariants test_exc_client_variants(behavior, false);
+      test_exc_client_variants.Run();
+    }
+
+    {
+      SCOPED_TRACE("all_fields = true");
+
+      TestExcClientVariants test_exc_client_variants(behavior, true);
+      test_exc_client_variants.Run();
+    }
+  }
+}
+
+}  // namespace