// Copyright 2014 The Crashpad Authors
//
// 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/mac/mach_o_image_annotations_reader.h"
#include <mach-o/loader.h>
#include <mach/mach.h>
#include <sys/types.h>
#include <utility>
#include "base/logging.h"
#include "client/crashpad_info.h"
#include "client/simple_string_dictionary.h"
#include "snapshot/mac/mach_o_image_reader.h"
#include "snapshot/mac/process_reader_mac.h"
#include "snapshot/snapshot_constants.h"
#include "util/stdlib/strnlen.h"
namespace crashpad {
MachOImageAnnotationsReader::MachOImageAnnotationsReader(
ProcessReaderMac* process_reader,
const MachOImageReader* image_reader,
const std::string& name)
: name_(name),
process_reader_(process_reader),
image_reader_(image_reader) {}
std::vector<std::string> MachOImageAnnotationsReader::Vector() const {
std::vector<std::string> vector_annotations;
ReadCrashReporterClientAnnotations(&vector_annotations);
ReadDyldErrorStringAnnotation(&vector_annotations);
return vector_annotations;
}
std::map<std::string, std::string> MachOImageAnnotationsReader::SimpleMap()
const {
std::map<std::string, std::string> simple_map_annotations;
ReadCrashpadSimpleAnnotations(&simple_map_annotations);
return simple_map_annotations;
}
std::vector<AnnotationSnapshot> MachOImageAnnotationsReader::AnnotationsList()
const {
std::vector<AnnotationSnapshot> annotations;
ReadCrashpadAnnotationsList(&annotations);
return annotations;
}
void MachOImageAnnotationsReader::ReadCrashReporterClientAnnotations(
std::vector<std::string>* vector_annotations) const {
mach_vm_address_t crash_info_address;
const process_types::section* crash_info_section =
image_reader_->GetSectionByName(
SEG_DATA, "__crash_info", &crash_info_address);
if (!crash_info_section) {
// On macOS 13, under some circumstances, `__crash_info` ends up in the
// `__DATA_DIRTY` segment. This is known to happen for `dyld`.
crash_info_section = image_reader_->GetSectionByName(
"__DATA_DIRTY", "__crash_info", &crash_info_address);
}
if (!crash_info_section) {
return;
}
process_types::crashreporter_annotations_t crash_info;
if (!crash_info.Read(process_reader_, crash_info_address)) {
LOG(WARNING) << "could not read crash info from " << name_;
return;
}
if (crash_info.version != 4 && crash_info.version != 5) {
LOG(WARNING) << "unexpected crash info version " << crash_info.version
<< " in " << name_;
return;
}
size_t expected_size =
process_types::crashreporter_annotations_t::ExpectedSizeForVersion(
process_reader_, crash_info.version);
if (crash_info_section->size < expected_size) {
LOG(WARNING) << "small crash info section size " << crash_info_section->size
<< " < " << expected_size << " for version "
<< crash_info.version << " in " << name_;
return;
}
// This number was totally made up out of nowhere, but it seems prudent to
// enforce some limit.
constexpr size_t kMaxMessageSize = 1024;
if (crash_info.message) {
std::string message;
if (process_reader_->Memory()->ReadCStringSizeLimited(
crash_info.message, kMaxMessageSize, &message)) {
vector_annotations->push_back(message);
} else {
LOG(WARNING) << "could not read crash message in " << name_;
}
}
if (crash_info.message2) {
std::string message;
if (process_reader_->Memory()->ReadCStringSizeLimited(
crash_info.message2, kMaxMessageSize, &message)) {
vector_annotations->push_back(message);
} else {
LOG(WARNING) << "could not read crash message 2 in " << name_;
}
}
}
void MachOImageAnnotationsReader::ReadDyldErrorStringAnnotation(
std::vector<std::string>* vector_annotations) const {
// dyld stores its error string at the external symbol for |const char
// error_string[1024]|. See 10.9.5 dyld-239.4/src/dyld.cpp error_string.
if (image_reader_->FileType() != MH_DYLINKER) {
return;
}
mach_vm_address_t error_string_address;
if (!image_reader_->LookUpExternalDefinedSymbol("_error_string",
&error_string_address)) {
return;
}
std::string message;
// 1024 here is distinct from kMaxMessageSize above, because it refers to a
// precisely-sized buffer inside dyld.
if (process_reader_->Memory()->ReadCStringSizeLimited(
error_string_address, 1024, &message)) {
if (!message.empty()) {
vector_annotations->push_back(message);
}
} else {
LOG(WARNING) << "could not read dylinker error string from " << name_;
}
}
void MachOImageAnnotationsReader::ReadCrashpadSimpleAnnotations(
std::map<std::string, std::string>* simple_map_annotations) const {
process_types::CrashpadInfo crashpad_info;
if (!image_reader_->GetCrashpadInfo(&crashpad_info) ||
!crashpad_info.simple_annotations) {
return;
}
std::vector<SimpleStringDictionary::Entry>
simple_annotations(SimpleStringDictionary::num_entries);
if (!process_reader_->Memory()->Read(
crashpad_info.simple_annotations,
simple_annotations.size() * sizeof(simple_annotations[0]),
&simple_annotations[0])) {
LOG(WARNING) << "could not read simple annotations from " << name_;
return;
}
for (const auto& entry : simple_annotations) {
size_t key_length = strnlen(entry.key, sizeof(entry.key));
if (key_length) {
std::string key(entry.key, key_length);
std::string value(entry.value, strnlen(entry.value, sizeof(entry.value)));
if (!simple_map_annotations->insert(std::make_pair(key, value)).second) {
LOG(INFO) << "duplicate simple annotation " << key << " in " << name_;
}
}
}
}
// TODO(https://crbug.com/crashpad/270): Replace implementations of
// ReadCrashpadAnnotationsList and ReadCrashpadSimpleAnnotations with the
// platform-agnostic implementations in ImageAnnotationReader.
void MachOImageAnnotationsReader::ReadCrashpadAnnotationsList(
std::vector<AnnotationSnapshot>* annotations) const {
process_types::CrashpadInfo crashpad_info;
if (!image_reader_->GetCrashpadInfo(&crashpad_info) ||
!crashpad_info.annotations_list) {
return;
}
process_types::AnnotationList annotation_list_object;
if (!annotation_list_object.Read(process_reader_,
crashpad_info.annotations_list)) {
LOG(WARNING) << "could not read annotations list object in " << name_;
return;
}
process_types::Annotation current = annotation_list_object.head;
for (size_t index = 0;
current.link_node != annotation_list_object.tail_pointer &&
index < kMaxNumberOfAnnotations;
++index) {
if (!current.Read(process_reader_, current.link_node)) {
LOG(WARNING) << "could not read annotation at index " << index << " in "
<< name_;
return;
}
if (current.size == 0) {
continue;
}
AnnotationSnapshot snapshot;
snapshot.type = current.type;
snapshot.value.resize(current.size);
if (!process_reader_->Memory()->ReadCStringSizeLimited(
current.name, Annotation::kNameMaxLength, &snapshot.name)) {
LOG(WARNING) << "could not read annotation name at index " << index
<< " in " << name_;
continue;
}
size_t size =
std::min(static_cast<size_t>(current.size), Annotation::kValueMaxSize);
if (!process_reader_->Memory()->Read(
current.value, size, snapshot.value.data())) {
LOG(WARNING) << "could not read annotation value at index " << index
<< " in " << name_;
continue;
}
annotations->push_back(std::move(snapshot));
}
}
} // namespace crashpad
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