crashpad/snapshot/ios/memory_snapshot_ios_intermediate_dump.cc
Justin Cohen b714b223ad ios: Actually merge memory snapshot data.
To avoid unnecessary duplication of potentially large memory regions,
the iOS MemorySnapshot data is owned by the intermediate dump. When
merging two iOS memory snapshots, it's necessary to copy the merged
data into a vector owned by the memory snapshot itself.

Previously the merged snapshot just contained the original data, which
leads to a heap overrun.

Bug: 1288544
Change-Id: I4eb392800141451db188d17c7b9f9ca9bd3bb603
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3399252
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
2022-01-19 00:00:04 +00:00

89 lines
3.2 KiB
C++

// Copyright 2020 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/ios/memory_snapshot_ios_intermediate_dump.h"
namespace crashpad {
namespace internal {
void MemorySnapshotIOSIntermediateDump::Initialize(vm_address_t address,
vm_address_t data,
vm_size_t size) {
INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
address_ = address;
data_ = data;
size_ = base::checked_cast<size_t>(size);
INITIALIZATION_STATE_SET_VALID(initialized_);
}
uint64_t MemorySnapshotIOSIntermediateDump::Address() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return address_;
}
size_t MemorySnapshotIOSIntermediateDump::Size() const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
return size_;
}
bool MemorySnapshotIOSIntermediateDump::Read(Delegate* delegate) const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
if (size_ == 0) {
return delegate->MemorySnapshotDelegateRead(nullptr, size_);
}
return delegate->MemorySnapshotDelegateRead(reinterpret_cast<void*>(data_),
size_);
}
const MemorySnapshot* MemorySnapshotIOSIntermediateDump::MergeWithOtherSnapshot(
const MemorySnapshot* other) const {
INITIALIZATION_STATE_DCHECK_VALID(initialized_);
auto other_snapshot =
reinterpret_cast<const MemorySnapshotIOSIntermediateDump*>(other);
INITIALIZATION_STATE_DCHECK_VALID(other_snapshot->initialized_);
if (other_snapshot->address_ < address_) {
return other_snapshot->MergeWithOtherSnapshot(this);
}
CheckedRange<uint64_t, size_t> merged(0, 0);
if (!LoggingDetermineMergedRange(this, other, &merged))
return nullptr;
auto result = std::make_unique<MemorySnapshotIOSIntermediateDump>();
result->Initialize(merged.base(), data_, merged.size());
if (size_ == merged.size()) {
return result.release();
}
const uint8_t* data = reinterpret_cast<const uint8_t*>(data_);
const uint8_t* other_data =
reinterpret_cast<const uint8_t*>(other_snapshot->data_);
vm_size_t overlap = merged.size() - other_snapshot->size_;
result->merged_data_.reserve(merged.size());
result->merged_data_.insert(result->merged_data_.end(), data, data + overlap);
result->merged_data_.insert(result->merged_data_.end(),
other_data,
other_data + other_snapshot->size_);
result->data_ =
reinterpret_cast<const vm_address_t>(result->merged_data_.data());
DCHECK_EQ(result->merged_data_.size(), merged.size());
return result.release();
}
} // namespace internal
} // namespace crashpad