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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.
#ifndef CRASHPAD_MINIDUMP_MINIDUMP_MEMORY_WRITER_H_
#define CRASHPAD_MINIDUMP_MINIDUMP_MEMORY_WRITER_H_
#include <windows.h>
#include <dbghelp.h>
#include <stdint.h>
#include <sys/types.h>
#include <memory>
#include <vector>
#include "base/macros.h"
#include "minidump/minidump_stream_writer.h"
#include "minidump/minidump_writable.h"
#include "snapshot/memory_snapshot.h"
#include "util/file/file_io.h"
namespace crashpad {
//! \brief The base class for writers of memory ranges pointed to by
//! MINIDUMP_MEMORY_DESCRIPTOR objects in a minidump file.
class SnapshotMinidumpMemoryWriter : public internal::MinidumpWritable,
public MemorySnapshot::Delegate {
public:
explicit SnapshotMinidumpMemoryWriter(const MemorySnapshot* memory_snapshot);
~SnapshotMinidumpMemoryWriter() override;
//! \brief Returns a MINIDUMP_MEMORY_DESCRIPTOR referencing the data that this
//! object writes.
//!
//! This method is expected to be called by a MinidumpMemoryListWriter in
//! order to obtain a MINIDUMP_MEMORY_DESCRIPTOR to include in its list.
//!
//! \note Valid in #kStateWritable.
const MINIDUMP_MEMORY_DESCRIPTOR* MinidumpMemoryDescriptor() const;
//! \brief Registers a memory descriptor as one that should point to the
//! object on which this method is called.
//!
//! This method is expected to be called by objects of other classes, when
//! those other classes have their own memory descriptors that need to point
//! to memory ranges within a minidump file. MinidumpThreadWriter is one such
//! class. This method is public for this reason, otherwise it would suffice
//! to be private.
//!
//! \note Valid in #kStateFrozen or any preceding state.
void RegisterMemoryDescriptor(MINIDUMP_MEMORY_DESCRIPTOR* memory_descriptor);
//! \brief Sets the underlying memory snapshot. Does not take ownership of \a
//! memory_snapshot.
void SetSnapshot(const MemorySnapshot* memory_snapshot) {
memory_snapshot_ = memory_snapshot;
}
private:
friend class MinidumpMemoryListWriter;
// MemorySnapshot::Delegate:
bool MemorySnapshotDelegateRead(void* data, size_t size) override;
// MinidumpWritable:
bool Freeze() override;
size_t SizeOfObject() final;
bool WriteObject(FileWriterInterface* file_writer) override;
//! \brief Returns the object’s desired byte-boundary alignment.
//!
//! Memory regions are aligned to a 16-byte boundary. The actual alignment
//! requirements of any data within the memory region are unknown, and may be
//! more or less strict than this depending on the platform.
//!
//! \return `16`.
//!
//! \note Valid in #kStateFrozen or any subsequent state.
size_t Alignment() override;
bool WillWriteAtOffsetImpl(FileOffset offset) override;
//! \brief Returns the object’s desired write phase.
//!
//! Memory regions are written at the end of minidump files, because it is
//! expected that unlike most other data in a minidump file, the contents of
//! memory regions will be accessed sparsely.
//!
//! \return #kPhaseLate.
//!
//! \note Valid in any state.
Phase WritePhase() final;
//! \brief Gets the underlying memory snapshot that the memory writer will
//! write to the minidump.
const MemorySnapshot* UnderlyingSnapshot() const { return memory_snapshot_; }
MINIDUMP_MEMORY_DESCRIPTOR memory_descriptor_;
// weak
std::vector<MINIDUMP_MEMORY_DESCRIPTOR*> registered_memory_descriptors_;
const MemorySnapshot* memory_snapshot_;
FileWriterInterface* file_writer_;
DISALLOW_COPY_AND_ASSIGN(SnapshotMinidumpMemoryWriter);
};
//! \brief The writer for a MINIDUMP_MEMORY_LIST stream in a minidump file,
//! containing a list of MINIDUMP_MEMORY_DESCRIPTOR objects.
class MinidumpMemoryListWriter final : public internal::MinidumpStreamWriter {
public:
MinidumpMemoryListWriter();
~MinidumpMemoryListWriter() override;
static bool CoalesceOwnedMemoryHelper(
std::unique_ptr<
crashpad::SnapshotMinidumpMemoryWriter,
std::default_delete<crashpad::SnapshotMinidumpMemoryWriter>>
snapshot);
//! \brief Adds a concrete initialized SnapshotMinidumpMemoryWriter for each
//! memory snapshot in \a memory_snapshots to the MINIDUMP_MEMORY_LIST.
//!
//! Memory snapshots are added in the fashion of AddMemory().
//!
//! \param[in] memory_snapshots The memory snapshots to use as source data.
//!
//! \note Valid in #kStateMutable.
void AddFromSnapshot(
const std::vector<const MemorySnapshot*>& memory_snapshots);
//! \brief Adds a SnapshotMinidumpMemoryWriter to the MINIDUMP_MEMORY_LIST.
//!
//! This object takes ownership of \a memory_writer and becomes its parent in
//! the overall tree of internal::MinidumpWritable objects.
//!
//! \note Valid in #kStateMutable.
void AddMemory(std::unique_ptr<SnapshotMinidumpMemoryWriter> memory_writer);
//! \brief Adds a SnapshotMinidumpMemoryWriter that’s a child of another
//! internal::MinidumpWritable object to the MINIDUMP_MEMORY_LIST.
//!
//! \a memory_writer does not become a child of this object, but the
//! MINIDUMP_MEMORY_LIST will still contain a MINIDUMP_MEMORY_DESCRIPTOR for
//! it. \a memory_writer must be a child of another object in the
//! internal::MinidumpWritable tree.
//!
//! This method exists to be called by objects that have their own
//! SnapshotMinidumpMemoryWriter children but wish for them to also appear in
//! the minidump file’s MINIDUMP_MEMORY_LIST. MinidumpThreadWriter, which has
//! a SnapshotMinidumpMemoryWriter for thread stack memory, is an example.
//!
//! \note Valid in #kStateMutable.
void AddNonOwnedMemory(SnapshotMinidumpMemoryWriter* memory_writer);
protected:
// MinidumpWritable:
bool Freeze() override;
size_t SizeOfObject() override;
std::vector<MinidumpWritable*> Children() override;
bool WriteObject(FileWriterInterface* file_writer) override;
// MinidumpStreamWriter:
MinidumpStreamType StreamType() const override;
//! \brief Merges any overlapping and abutting memory ranges that were added
//! via AddFromSnapshot() and AddMemory() into single entries.
//!
//! This is expected to be called once just before writing, generally from
//! Freeze().
//!
//! This function has the side-effect of merging owned ranges, dropping any
//! owned ranges that overlap with non-owned ranges, removing empty ranges,
//! and sorting all ranges by address.
//!
//! Per its name, this coalesces owned memory, however, this is not a complete
//! solution for ensuring that no overlapping memory ranges are emitted in the
//! minidump. In particular, if AddNonOwnedMemory() is used to add multiple
//! overlapping ranges, then overlapping ranges will still be emitted to the
//! minidump. Currently, AddNonOwnedMemory() is used only for adding thread
//! stacks, so overlapping shouldn't be a problem in practice. For more
//! details see https://crashpad.chromium.org/bug/61 and
//! https://crrev.com/c/374539.
void CoalesceOwnedMemory();
private:
//! \brief Drops children_ ranges that overlap non_owned_memory_writers_.
void DropRangesThatOverlapNonOwned();
std::vector<SnapshotMinidumpMemoryWriter*> non_owned_memory_writers_; // weak
std::vector<std::unique_ptr<SnapshotMinidumpMemoryWriter>> children_;
std::vector<std::unique_ptr<const MemorySnapshot>>
snapshots_created_during_merge_;
std::vector<SnapshotMinidumpMemoryWriter*> all_memory_writers_; // weak
MINIDUMP_MEMORY_LIST memory_list_base_;
DISALLOW_COPY_AND_ASSIGN(MinidumpMemoryListWriter);
};
} // namespace crashpad
#endif // CRASHPAD_MINIDUMP_MINIDUMP_MEMORY_WRITER_H_