fuchsia: Implementation of MultiprocessExec

This supports multiprocess tests of the non-fork() variety.

Also, improve directory finding so that the
crashpad_test_test_multiprocess_exec_test_child binary can be located
correctly on Fuchsia.

Doc ref for launchpad:
https://fuchsia.googlesource.com/zircon/+/master/system/ulib/launchpad/include/launchpad/launchpad.h#23

Also, roll mini_chromium to pick up ScopedZxHandle addition. Includes:
a19ef08 Merge ScopedZxHandle from Chromium base
f21c900 fuchsia: Move zircon libs dep to base, rather than global

Bug: crashpad:196
Change-Id: Id01dee43f2d04e682e70c12777aff41f8dd848d6
Reviewed-on: https://chromium-review.googlesource.com/868967
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Scott Graham <scottmg@chromium.org>

DEPS

@@ -28,7 +28,7 @@ deps = {
       '5e2b3ddde7cda5eb6bc09a5546a76b00e49d888f',
   'crashpad/third_party/mini_chromium/mini_chromium':
       Var('chromium_git') + '/chromium/mini_chromium@' +
-      'edfe51ce818e55eae73ab3f144a360e855533888',
+      'a19ef08ada53345fd9277f3d9434bc35f0e13a55',
   'crashpad/third_party/zlib/zlib':
       Var('chromium_git') + '/chromium/src/third_party/zlib@' +
       '13dc246a58e4b72104d35f9b1809af95221ebda7',

test/BUILD.gn

@@ -42,13 +42,13 @@ static_library("test") {
   ]
 
   if (crashpad_is_posix) {
-    sources += [
-      "multiprocess_posix.cc",
-      "scoped_temp_dir_posix.cc",
-    ]
+    sources += [ "scoped_temp_dir_posix.cc" ]
 
     if (!crashpad_is_fuchsia) {
-      sources += [ "multiprocess_exec_posix.cc" ]
+      sources += [
+        "multiprocess_exec_posix.cc",
+        "multiprocess_posix.cc",
+      ]
     }
   }
 
@@ -91,6 +91,11 @@ static_library("test") {
     ]
   }
 
+  if (crashpad_is_fuchsia) {
+    sources += [ "multiprocess_exec_fuchsia.cc" ]
+    libs = [ "launchpad" ]
+  }
+
   public_configs = [ "..:crashpad_config" ]
 
   configs += [ "../build:crashpad_is_in_chromium" ]
@@ -121,6 +126,7 @@ source_set("test_test") {
   sources = [
     "hex_string_test.cc",
     "main_arguments_test.cc",
+    "multiprocess_exec_test.cc",
     "scoped_temp_dir_test.cc",
     "test_paths_test.cc",
   ]
@@ -141,11 +147,6 @@ source_set("test_test") {
   }
 
   if (!crashpad_is_fuchsia) {
-    sources += [
-      # TODO(scottmg): A MultiprocessExecFuchsia is probably desirable, but
-      # hasn't been implemented yet.
-      "multiprocess_exec_test.cc",
-    ]
   }
 
   deps = [

test/multiprocess.h

@@ -36,8 +36,8 @@ struct MultiprocessInfo;
 //! Subclasses are expected to implement the parent and child by overriding the
 //! appropriate methods.
 //!
-//! On Windows, this class is only an internal implementation detail of
-//! MultiprocessExec and all tests must use that class.
+//! On Windows and Fuchsia, this class is only an internal implementation
+//! detail of MultiprocessExec and all tests must use that class.
 class Multiprocess {
  public:
   //! \brief The termination type for a child process.
@@ -110,14 +110,18 @@ class Multiprocess {
   //!
   //! Subclass implementations may signal failure by raising their own fatal
   //! gtest assertions.
-  virtual void PreFork();
+  virtual void PreFork()
+#if defined(OS_WIN) || defined(OS_FUCHSIA)
+      = 0
+#endif  // OS_WIN || OS_FUCHSIA
+      ;
 
-#if !defined(OS_WIN)
+#if !defined(OS_WIN) && !defined(OS_FUCHSIA)
   //! \brief Returns the child process’ process ID.
   //!
   //! This method may only be called by the parent process.
   pid_t ChildPID() const;
-#endif  // !OS_WIN
+#endif  // !OS_WIN && !OS_FUCHSIA
 
   //! \brief Returns the read pipe’s file handle.
   //!

test/multiprocess_exec_fuchsia.cc

@@ -0,0 +1,155 @@
+// Copyright 2018 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 "test/multiprocess_exec.h"
+
+#include <launchpad/launchpad.h>
+#include <zircon/process.h>
+#include <zircon/syscalls.h>
+
+#include "base/files/scoped_file.h"
+#include "base/fuchsia/fuchsia_logging.h"
+#include "base/fuchsia/scoped_zx_handle.h"
+#include "gtest/gtest.h"
+
+namespace crashpad {
+namespace test {
+
+namespace internal {
+
+struct MultiprocessInfo {
+  MultiprocessInfo() {}
+  base::ScopedFD stdin_write;
+  base::ScopedFD stdout_read;
+  base::ScopedZxHandle child;
+};
+
+}  // namespace internal
+
+Multiprocess::Multiprocess()
+    : info_(nullptr),
+      code_(EXIT_SUCCESS),
+      reason_(kTerminationNormal) {
+}
+
+void Multiprocess::Run() {
+  // Set up and spawn the child process.
+  ASSERT_NO_FATAL_FAILURE(PreFork());
+  RunChild();
+
+  // And then run the parent actions in this process.
+  RunParent();
+
+  // Reap the child.
+  zx_signals_t signals;
+  ASSERT_EQ(
+      zx_object_wait_one(
+          info_->child.get(), ZX_TASK_TERMINATED, ZX_TIME_INFINITE, &signals),
+      ZX_OK);
+  ASSERT_EQ(signals, ZX_TASK_TERMINATED);
+}
+
+Multiprocess::~Multiprocess() {
+  delete info_;
+}
+
+FileHandle Multiprocess::ReadPipeHandle() const {
+  return info_->stdout_read.get();
+}
+
+FileHandle Multiprocess::WritePipeHandle() const {
+  return info_->stdin_write.get();
+}
+
+void Multiprocess::CloseReadPipe() {
+  info_->stdout_read.reset();
+}
+
+void Multiprocess::CloseWritePipe() {
+  info_->stdin_write.reset();
+}
+
+void Multiprocess::RunParent() {
+  MultiprocessParent();
+
+  info_->stdout_read.reset();
+  info_->stdin_write.reset();
+}
+
+void Multiprocess::RunChild() {
+  MultiprocessChild();
+}
+
+MultiprocessExec::MultiprocessExec()
+    : Multiprocess(), command_(), arguments_(), argv_() {
+}
+
+void MultiprocessExec::SetChildCommand(
+    const base::FilePath& command,
+    const std::vector<std::string>* arguments) {
+  command_ = command;
+  if (arguments) {
+    arguments_ = *arguments;
+  } else {
+    arguments_.clear();
+  }
+}
+
+MultiprocessExec::~MultiprocessExec() {}
+
+void MultiprocessExec::PreFork() {
+  ASSERT_FALSE(command_.empty());
+
+  ASSERT_TRUE(argv_.empty());
+
+  argv_.push_back(command_.value().c_str());
+  for (const std::string& argument : arguments_) {
+    argv_.push_back(argument.c_str());
+  }
+
+  ASSERT_EQ(info(), nullptr);
+  set_info(new internal::MultiprocessInfo());
+}
+
+void MultiprocessExec::MultiprocessChild() {
+  launchpad_t* lp;
+  launchpad_create(zx_job_default(), command_.value().c_str(), &lp);
+  launchpad_load_from_file(lp, command_.value().c_str());
+  launchpad_set_args(lp, argv_.size(), &argv_[0]);
+
+  // Pass the filesystem namespace, parent environment, and default job to the
+  // child, but don't include any other file handles, preferring to set them
+  // up explicitly below.
+  launchpad_clone(
+      lp, LP_CLONE_FDIO_NAMESPACE | LP_CLONE_ENVIRON | LP_CLONE_DEFAULT_JOB);
+
+  int stdin_parent_side;
+  launchpad_add_pipe(lp, &stdin_parent_side, STDIN_FILENO);
+  info()->stdin_write.reset(stdin_parent_side);
+
+  int stdout_parent_side;
+  launchpad_add_pipe(lp, &stdout_parent_side, STDOUT_FILENO);
+  info()->stdout_read.reset(stdout_parent_side);
+
+  launchpad_clone_fd(lp, STDERR_FILENO, STDERR_FILENO);
+
+  const char* error_message;
+  zx_handle_t child;
+  zx_status_t status = launchpad_go(lp, &child, &error_message);
+  ZX_CHECK(status == ZX_OK, status) << "launchpad_go: " << error_message;
+  info()->child.reset(child);
+}
+
+}  // namespace test
+}  // namespace crashpad

test/multiprocess_exec_win.cc

@@ -61,10 +61,6 @@ Multiprocess::~Multiprocess() {
   delete info_;
 }
 
-void Multiprocess::PreFork() {
-  NOTREACHED();
-}
-
 FileHandle Multiprocess::ReadPipeHandle() const {
   // This is the parent case, it's stdin in the child.
   return info_->pipe_c2p_read.get();

test/test_paths.cc

@@ -170,7 +170,7 @@ base::FilePath TestPaths::BuildArtifact(
 
   base::FilePath::StringType test_name =
       FILE_PATH_LITERAL("crashpad_") + module + FILE_PATH_LITERAL("_test");
-#if !defined(CRASHPAD_IS_IN_CHROMIUM)
+#if !defined(CRASHPAD_IS_IN_CHROMIUM) && !defined(OS_FUCHSIA)
   CHECK(Executable().BaseName().RemoveFinalExtension().value() == test_name);
 #endif  // !CRASHPAD_IS_IN_CHROMIUM
 
@@ -182,6 +182,8 @@ base::FilePath TestPaths::BuildArtifact(
     case FileType::kExecutable:
 #if defined(OS_WIN)
       extension = FILE_PATH_LITERAL(".exe");
+#elif defined(OS_FUCHSIA)
+      directory = base::FilePath(FILE_PATH_LITERAL("/pkg/bin"));
 #endif  // OS_WIN
       break;
 
@@ -191,6 +193,10 @@ base::FilePath TestPaths::BuildArtifact(
 #else  // OS_WIN
       extension = FILE_PATH_LITERAL(".so");
 #endif  // OS_WIN
+
+#if defined(OS_FUCHSIA)
+      directory = base::FilePath(FILE_PATH_LITERAL("/pkg/lib"));
+#endif
       break;
   }
 

util/misc/paths_fuchsia.cc

@@ -26,9 +26,8 @@ namespace crashpad {
 bool Paths::Executable(base::FilePath* path) {
   // Assume the environment has been set up following
   // https://fuchsia.googlesource.com/docs/+/master/namespaces.md#typical-directory-structure
-  // . The actual executable name is not known, but it's conceptually in this
-  // location.
-  *path = base::FilePath("/pkg/bin/unknown");
+  // .
+  *path = base::FilePath("/pkg/bin/app");
   return true;
 }