crashpad/util/process/process_memory.cc
Joshua Peraza e7fe120d8b ProcessMemory: Add ReadUpTo to enable short reads
ProcessMemory::ReadCStringInternal needs to be able to perform short
reads.

Change-Id: I2b2e1c2e6603d01235d8d2dbd15494375cd7f3f6
Reviewed-on: https://chromium-review.googlesource.com/874776
Commit-Queue: Joshua Peraza <jperaza@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Scott Graham <scottmg@chromium.org>
2018-01-18 19:59:59 +00:00

79 lines
2.1 KiB
C++

// 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 "util/process/process_memory.h"
#include "base/logging.h"
namespace crashpad {
bool ProcessMemory::Read(VMAddress address, size_t size, void* buffer) const {
char* buffer_c = static_cast<char*>(buffer);
while (size > 0) {
ssize_t bytes_read = ReadUpTo(address, size, buffer_c);
if (bytes_read < 0) {
return false;
}
if (bytes_read == 0) {
LOG(ERROR) << "short read";
return false;
}
DCHECK_LE(static_cast<size_t>(bytes_read), size);
size -= bytes_read;
address += bytes_read;
buffer_c += bytes_read;
}
return true;
}
bool ProcessMemory::ReadCStringInternal(VMAddress address,
bool has_size,
size_t size,
std::string* string) const {
string->clear();
char buffer[4096];
do {
size_t read_size;
if (has_size) {
read_size = std::min(sizeof(buffer), size);
} else {
read_size = sizeof(buffer);
}
ssize_t bytes_read = ReadUpTo(address, read_size, buffer);
if (bytes_read < 0) {
return false;
}
if (bytes_read == 0) {
break;
}
char* nul = static_cast<char*>(memchr(buffer, '\0', bytes_read));
if (nul != nullptr) {
string->append(buffer, nul - buffer);
return true;
}
string->append(buffer, bytes_read);
address += bytes_read;
size -= bytes_read;
} while (!has_size || size > 0);
LOG(ERROR) << "unterminated string";
return false;
}
} // namespace crashpad