Add CRASHPAD_SIMULATE_CRASH() and supporting client code

client/simulate_crash_mac_test.cc

Index: client/simulate_crash_mac_test.cc
diff --git a/client/simulate_crash_mac_test.cc b/client/simulate_crash_mac_test.cc
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index 0000000000000000000000000000000000000000..813dc6159048891e211bd9ac75695087413a77b2
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+// 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 "client/simulate_crash.h"
+
+#include <mach/mach.h>
+#include <string.h>
+
+#include "base/basictypes.h"
+#include "base/strings/stringprintf.h"
+#include "build/build_config.h"
+#include "gtest/gtest.h"
+#include "util/mach/exc_server_variants.h"
+#include "util/mach/exception_behaviors.h"
+#include "util/mach/exception_ports.h"
+#include "util/mach/mach_extensions.h"
+#include "util/mach/mach_message_server.h"
+#include "util/mach/symbolic_constants_mach.h"
+#include "util/test/mac/mach_errors.h"
+#include "util/test/mac/mach_multiprocess.h"
+
+namespace crashpad {
+namespace test {
+namespace {
+
+class TestSimulateCrashMac final : public MachMultiprocess,
+                                   public UniversalMachExcServer {
+ public:
+  // Defines which targets the child should set an EXC_CRASH exception handler
+  // for.
+  enum ExceptionPortsTarget {
+    // The child should clear its EXC_CRASH handler for both its task and thread
+    // targets. SimulateCrash() will attempt to deliver the exception to the
+    // host target, which will fail if not running as root. In any case, the
+    // parent should not expect to receive any exception message from the child.
+    kExceptionPortsTargetNone = 0,
+
+    // The child will set an EXC_CRASH handler for its task target, and clear it
+    // for its thread target. The parent runs an exception server to receive
+    // the child’s simulated crash message.
+    kExceptionPortsTargetTask,
+
+    // The child will set an EXC_CRASH handler for its thread target, and clear
+    // it for its task target. The parent runs an exception server to receive
+    // the child’s simulated crash message.
+    kExceptionPortsTargetThread,
+
+    // The child sets an EXC_CRASH handler for both its task and thread targets.
+    // The parent runs an exception server to receive the message expected to be
+    // delivered to the thread target, but returns an error code. The child will
+    // then fall back to trying the server registered for the task target,
+    // sending a second message to the parent. The server in the parent will
+    // handle this one successfully.
+    kExceptionPortsTargetBoth,
+  };
+
+  TestSimulateCrashMac(ExceptionPortsTarget target,
+                       exception_behavior_t behavior,
+                       thread_state_flavor_t flavor)
+      : target_(target),
+        behavior_(behavior),
+        flavor_(flavor),
+        succeed_(true) {
+  }
+
+  ~TestSimulateCrashMac() {}
+
+  // UniversalMachExcServer:
+  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;
+
+    // Check the entire exception message, because most or all of it was
+    // generated by SimulateCrash() instead of the kernel.
+
+    EXPECT_EQ(behavior_, behavior);
+    EXPECT_EQ(LocalPort(), exception_port);
+    if (ExceptionBehaviorHasIdentity(behavior)) {
+      EXPECT_NE(THREAD_NULL, thread);
+      EXPECT_EQ(ChildTask(), task);
+    } else {
+      EXPECT_EQ(THREAD_NULL, thread);
+      EXPECT_EQ(TASK_NULL, task);
+    }
+    EXPECT_EQ(kMachExceptionSimulated, exception);
+    EXPECT_EQ(2u, code_count);
+    if (code_count >= 1) {
+      EXPECT_EQ(0, code[0]);
+    }
+    if (code_count >= 2) {
+      EXPECT_EQ(0, code[1]);
+    }
+    if (!ExceptionBehaviorHasState(behavior)) {
+      EXPECT_EQ(THREAD_STATE_NONE, *flavor);
+    } else {
+      EXPECT_EQ(flavor_, *flavor);
+      switch (*flavor) {
+#if defined(ARCH_CPU_X86_FAMILY)
+        case x86_THREAD_STATE: {
+          EXPECT_EQ(x86_THREAD_STATE_COUNT, old_state_count);
+          const x86_thread_state* state =
+              reinterpret_cast<const x86_thread_state*>(old_state);
+          switch (state->tsh.flavor) {
+            case x86_THREAD_STATE32:
+              EXPECT_EQ(static_cast<int>(x86_THREAD_STATE32_COUNT),
+                        state->tsh.count);
+              break;
+            case x86_THREAD_STATE64:
+              EXPECT_EQ(static_cast<int>(x86_THREAD_STATE64_COUNT),
+                        state->tsh.count);
+              break;
+            default:
+              ADD_FAILURE() << "unexpected tsh.flavor " << state->tsh.flavor;
+              break;
+          }
+          break;
+        }
+        case x86_FLOAT_STATE: {
+          EXPECT_EQ(x86_FLOAT_STATE_COUNT, old_state_count);
+          const x86_float_state* state =
+              reinterpret_cast<const x86_float_state*>(old_state);
+          switch (state->fsh.flavor) {
+            case x86_FLOAT_STATE32:
+              EXPECT_EQ(static_cast<int>(x86_FLOAT_STATE32_COUNT),
+                        state->fsh.count);
+              break;
+            case x86_FLOAT_STATE64:
+              EXPECT_EQ(static_cast<int>(x86_FLOAT_STATE64_COUNT),
+                        state->fsh.count);
+              break;
+            default:
+              ADD_FAILURE() << "unexpected fsh.flavor " << state->fsh.flavor;
+              break;
+          }
+          break;
+        }
+        case x86_DEBUG_STATE: {
+          EXPECT_EQ(x86_DEBUG_STATE_COUNT, old_state_count);
+          const x86_debug_state* state =
+              reinterpret_cast<const x86_debug_state*>(old_state);
+          switch (state->dsh.flavor) {
+            case x86_DEBUG_STATE32:
+              EXPECT_EQ(static_cast<int>(x86_DEBUG_STATE32_COUNT),
+                        state->dsh.count);
+              break;
+            case x86_DEBUG_STATE64:
+              EXPECT_EQ(static_cast<int>(x86_DEBUG_STATE64_COUNT),
+                        state->dsh.count);
+              break;
+            default:
+              ADD_FAILURE() << "unexpected dsh.flavor " << state->dsh.flavor;
+              break;
+          }
+          break;
+        }
+        case x86_THREAD_STATE32:
+          EXPECT_EQ(x86_THREAD_STATE32_COUNT, old_state_count);
+          break;
+        case x86_FLOAT_STATE32:
+          EXPECT_EQ(x86_FLOAT_STATE32_COUNT, old_state_count);
+          break;
+        case x86_DEBUG_STATE32:
+          EXPECT_EQ(x86_DEBUG_STATE32_COUNT, old_state_count);
+          break;
+        case x86_THREAD_STATE64:
+          EXPECT_EQ(x86_THREAD_STATE64_COUNT, old_state_count);
+          break;
+        case x86_FLOAT_STATE64:
+          EXPECT_EQ(x86_FLOAT_STATE64_COUNT, old_state_count);
+          break;
+        case x86_DEBUG_STATE64:
+          EXPECT_EQ(x86_DEBUG_STATE64_COUNT, old_state_count);
+          break;
+#else
+#error Port to your CPU architecture
+#endif
+        default:
+          ADD_FAILURE() << "unexpected flavor " << *flavor;
+          break;
+      }
+
+      // Attempt to set a garbage thread state, which would cause the child to
+      // crash inside SimulateCrash() if it actually succeeded. This tests that
+      // SimulateCrash() ignores new_state instead of attempting to set the
+      // state as the kernel would do. This operates in conjunction with the
+      // |true| argument to ExcServerSuccessfulReturnValue() below.
+      *new_state_count = old_state_count;
+      size_t new_state_size = sizeof(natural_t) * old_state_count;
+      memset(new_state, 0xa5, new_state_size);
+    }
+
+    if (!succeed_) {
+      // The client has registered EXC_CRASH handlers for both its thread and
+      // task targets, and sent a simulated exception message to its
+      // thread-level EXC_CRASH handler. To test that it will fall back to
+      // trying the task-level EXC_CRASH handler, return a failure code, which
+      // should cause SimulateCrash() to try the next target.
+      EXPECT_EQ(kExceptionPortsTargetBoth, target_);
+      return KERN_ABORTED;
+    }
+
+    return ExcServerSuccessfulReturnValue(behavior, true);
+  }
+
+ private:
+  // MachMultiprocess:
+
+  void MachMultiprocessParent() override {
+    if (target_ == kExceptionPortsTargetNone) {
+      // The child does not have any EXC_CRASH handlers registered for its
+      // thread or task targets, so no exception message is expected to be
+      // generated. Don’t run the server at all.
+      return;
+    }
+
+    mach_msg_return_t mr;
+    if (target_ == kExceptionPortsTargetBoth) {
+      // The client has registered EXC_CRASH handlers for both its thread and
+      // task targets. Run a server that will return a failure code when the
+      // exception message is sent to the thread target, which will cause the
+      // client to fall back to the task target and send another message.
+      succeed_ = false;
+      mr = MachMessageServer::Run(this,
+                                  LocalPort(),
+                                  MACH_MSG_OPTION_NONE,
+                                  MachMessageServer::kOneShot,
+                                  MachMessageServer::kBlocking,
+                                  MACH_MSG_TIMEOUT_NONE);
+      EXPECT_EQ(MACH_MSG_SUCCESS, mr)
+          << MachErrorMessage(mr, "MachMessageServer::Run");
+    }
+
+    succeed_ = true;
+    mr = MachMessageServer::Run(this,
+                                LocalPort(),
+                                MACH_MSG_OPTION_NONE,
+                                MachMessageServer::kOneShot,
+                                MachMessageServer::kBlocking,
+                                MACH_MSG_TIMEOUT_NONE);
+    EXPECT_EQ(MACH_MSG_SUCCESS, mr)
+        << MachErrorMessage(mr, "MachMessageServer::Run");
+  }
+
+  void MachMultiprocessChild() override {
+    bool task_valid = target_ == kExceptionPortsTargetTask ||
+                      target_ == kExceptionPortsTargetBoth;
+    ExceptionPorts task_exception_ports(ExceptionPorts::kTargetTypeTask,
+                                        TASK_NULL);
+    ASSERT_TRUE(task_exception_ports.SetExceptionPort(
+        EXC_MASK_CRASH,
+        task_valid ? RemotePort() : MACH_PORT_NULL,
+        behavior_,
+        flavor_));
+
+    bool thread_valid = target_ == kExceptionPortsTargetThread ||
+                        target_ == kExceptionPortsTargetBoth;
+    ExceptionPorts thread_exception_ports(ExceptionPorts::kTargetTypeThread,
+                                          THREAD_NULL);
+    ASSERT_TRUE(thread_exception_ports.SetExceptionPort(
+        EXC_MASK_CRASH,
+        thread_valid ? RemotePort() : MACH_PORT_NULL,
+        behavior_,
+        flavor_));
+
+    CRASHPAD_SIMULATE_CRASH();
+  }
+
+  ExceptionPortsTarget target_;
+  exception_behavior_t behavior_;
+  thread_state_flavor_t flavor_;
+  bool succeed_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestSimulateCrashMac);
+};
+
+TEST(SimulateCrash, SimulateCrash) {
+  const TestSimulateCrashMac::ExceptionPortsTarget kTargets[] = {
+      TestSimulateCrashMac::kExceptionPortsTargetNone,
+      TestSimulateCrashMac::kExceptionPortsTargetTask,
+      TestSimulateCrashMac::kExceptionPortsTargetThread,
+      TestSimulateCrashMac::kExceptionPortsTargetBoth,
+  };
+
+  const exception_behavior_t kBehaviors[] = {
+      EXCEPTION_DEFAULT,
+      EXCEPTION_STATE,
+      EXCEPTION_STATE_IDENTITY,
+      EXCEPTION_DEFAULT | kMachExceptionCodes,
+      EXCEPTION_STATE | kMachExceptionCodes,
+      EXCEPTION_STATE_IDENTITY | kMachExceptionCodes,
+  };
+
+  const thread_state_flavor_t kFlavors[] = {
+#if defined(ARCH_CPU_X86_FAMILY)
+      x86_THREAD_STATE,
+      x86_FLOAT_STATE,
+      x86_DEBUG_STATE,
+#if defined(ARCH_CPU_X86)
+      x86_THREAD_STATE32,
+      x86_FLOAT_STATE32,
+      x86_DEBUG_STATE32,
+#elif defined(ARCH_CPU_X86_64)
+      x86_THREAD_STATE64,
+      x86_FLOAT_STATE64,
+      x86_DEBUG_STATE64,
+#endif
+#else
+#error Port to your CPU architecture
+#endif
+  };
+
+  for (size_t target_index = 0;
+       target_index < arraysize(kTargets);
+       ++target_index) {
+    TestSimulateCrashMac::ExceptionPortsTarget target = kTargets[target_index];
+    SCOPED_TRACE(base::StringPrintf(
+        "target_index %zu, target %d", target_index, target));
+
+    for (size_t behavior_index = 0;
+         behavior_index < arraysize(kBehaviors);
+         ++behavior_index) {
+      exception_behavior_t behavior = kBehaviors[behavior_index];
+      SCOPED_TRACE(base::StringPrintf(
+          "behavior_index %zu, behavior %s",
+          behavior_index,
+          ExceptionBehaviorToString(behavior, kUseFullName | kUnknownIsNumeric)
+              .c_str()));
+
+      if (!ExceptionBehaviorHasState(behavior)) {
+        TestSimulateCrashMac test_simulate_crash_mac(
+            target, behavior, THREAD_STATE_NONE);
+        test_simulate_crash_mac.Run();
+      } else {
+        for (size_t flavor_index = 0;
+             flavor_index < arraysize(kFlavors);
+             ++flavor_index) {
+          thread_state_flavor_t flavor = kFlavors[flavor_index];
+          SCOPED_TRACE(base::StringPrintf(
+              "flavor_index %zu, flavor %s",
+              flavor_index,
+              ThreadStateFlavorToString(
+                  flavor, kUseFullName | kUnknownIsNumeric).c_str()));
+
+          TestSimulateCrashMac test_simulate_crash_mac(
+              target, behavior, flavor);
+          test_simulate_crash_mac.Run();
+        }
+      }
+    }
+  }
+}
+
+}  // namespace
+}  // namespace test
+}  // namespace crashpad