Add MemorySnapshotLinux

Bug: crashpad:30
Change-Id: Iddd100c3806178f6d20dd903e3f41926904696d4
Reviewed-on: https://chromium-review.googlesource.com/577977
Reviewed-by: Mark Mentovai <mark@chromium.org>

snapshot/linux/memory_snapshot_linux.cc

@@ -0,0 +1,68 @@
+// Copyright 2017 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 "snapshot/linux/memory_snapshot_linux.h"
+
+#include <memory>
+
+namespace crashpad {
+namespace internal {
+
+MemorySnapshotLinux::MemorySnapshotLinux()
+    : MemorySnapshot(),
+      process_reader_(nullptr),
+      address_(0),
+      size_(0),
+      initialized_() {
+}
+
+MemorySnapshotLinux::~MemorySnapshotLinux() {
+}
+
+void MemorySnapshotLinux::Initialize(ProcessReader* process_reader,
+                                     LinuxVMAddress address,
+                                     size_t size) {
+  INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
+  process_reader_ = process_reader;
+  address_ = address;
+  size_ = size;
+  INITIALIZATION_STATE_SET_VALID(initialized_);
+}
+
+uint64_t MemorySnapshotLinux::Address() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return address_;
+}
+
+size_t MemorySnapshotLinux::Size() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return size_;
+}
+
+bool MemorySnapshotLinux::Read(Delegate* delegate) const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
+  if (size_ == 0) {
+    return delegate->MemorySnapshotDelegateRead(nullptr, size_);
+  }
+
+  std::unique_ptr<uint8_t[]> buffer(new uint8_t[size_]);
+  if (!process_reader_->Memory()->Read(address_, size_, buffer.get())) {
+    return false;
+  }
+  return delegate->MemorySnapshotDelegateRead(buffer.get(), size_);
+}
+
+}  // namespace internal
+}  // namespace crashpad

snapshot/linux/memory_snapshot_linux.h

@@ -0,0 +1,69 @@
+// Copyright 2017 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.
+
+#ifndef CRASHPAD_SNAPSHOT_LINUX_MEMORY_SNAPSHOT_LINUX_H_
+#define CRASHPAD_SNAPSHOT_LINUX_MEMORY_SNAPSHOT_LINUX_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "base/macros.h"
+#include "snapshot/linux/process_reader.h"
+#include "snapshot/memory_snapshot.h"
+#include "util/linux/address_types.h"
+#include "util/misc/initialization_state_dcheck.h"
+
+namespace crashpad {
+namespace internal {
+
+//! \brief A MemorySnapshot of a memory region in a process on the running
+//!     system, when the system runs Linux.
+class MemorySnapshotLinux final : public MemorySnapshot {
+ public:
+  MemorySnapshotLinux();
+  ~MemorySnapshotLinux() override;
+
+  //! \brief Initializes the object.
+  //!
+  //! Memory is read lazily. No attempt is made to read the memory snapshot data
+  //! until Read() is called, and the memory snapshot data is discared when
+  //! Read() returns.
+  //!
+  //! \param[in] process_reader A reader for the process being snapshotted.
+  //! \param[in] address The base address of the memory region to snapshot, in
+  //!     the snapshot process’ address space.
+  //! \param[in] size The size of the memory region to snapshot.
+  void Initialize(ProcessReader* process_reader,
+                  LinuxVMAddress address,
+                  size_t size);
+
+  // MemorySnapshot:
+
+  uint64_t Address() const override;
+  size_t Size() const override;
+  bool Read(Delegate* delegate) const override;
+
+ private:
+  ProcessReader* process_reader_;  // weak
+  uint64_t address_;
+  size_t size_;
+  InitializationStateDcheck initialized_;
+
+  DISALLOW_COPY_AND_ASSIGN(MemorySnapshotLinux);
+};
+
+}  // namespace internal
+}  // namespace crashpad
+
+#endif  // CRASHPAD_SNAPSHOT_LINUX_MEMORY_SNAPSHOT_LINUX_H_

snapshot/snapshot.gyp

@@ -50,6 +50,8 @@
         'linux/elf_image_reader.h',
         'linux/elf_symbol_table_reader.cc',
         'linux/elf_symbol_table_reader.h',
+        'linux/memory_snapshot_linux.cc',
+        'linux/memory_snapshot_linux.h',
         'linux/process_reader.cc',
         'linux/process_reader.h',
         'mac/cpu_context_mac.cc',