addressmap.cc

/*-
 * Copyright (c) 2015 David T. Chisnall
 *
 * All rights reserved.
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
 * ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-11-C-0249
 * ("MRC2"), as part of the DARPA MRC research programme.
 *
 * @BERI_LICENSE_HEADER_START@
 *
 * Licensed to BERI Open Systems C.I.C. (BERI) under one or more contributor
 * license agreements.  See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.  BERI licenses this
 * file to you under the BERI Hardware-Software License, Version 1.0 (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.beri-open-systems.org/legal/license-1-0.txt
 *
 * Unless required by applicable law or agreed to in writing, Work 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.
 *
 * @BERI_LICENSE_HEADER_END@
 */

#include <vector>
#include <fstream>
#include <regex>
#include "addressmap.hh"

#include <iostream>

namespace {

/**
 * Concrete class that implements the address map interface.
 */
struct concrete_addressmap : cheri::addressmap
{
	std::vector<range> ranges;
	range mapping_for_address(uint64_t addr) override
	{
		for (auto &r : ranges)
		{
			if ((r.start <= addr) && (addr <= r.end))
			{
				return r;
			}
		}
		range empty;
		return empty;
	}
};
} // anonymous namespace 

std::shared_ptr<cheri::addressmap> cheri::addressmap::open_procstat(std::string path)
{
	std::ifstream file(path, std::ios::in);
	if (!file.is_open())
	{
		return nullptr;
	}
	// FIXME: file fails to open
	std::shared_ptr<concrete_addressmap> ret = std::make_shared<concrete_addressmap>();
	std::string line;
	// Regular expression for matching a line in a procstat entry.
	std::regex re("\\s*\\d+\\s+0x([0-9a-f]+)\\s+0x([0-9a-f]+)\\s+([r-])([w-])([x-])\\s+\\d+\\s+\\d+\\s+\\d+\\s+\\d+\\s+\\S+\\s+\\S+\\s*(\\S*)",
			std::regex_constants::ECMAScript);
	auto end = std::sregex_iterator();
	while (std::getline(file, line))
	{
		if (line.find("  PID") != std::string::npos)
		{
			continue;
		}
		auto begin = std::sregex_iterator(line.begin(), line.end(), re);
		for (auto i=begin ; i!=end ; ++i)
		{
			if (i->size() != 7)
			{
				continue;
			}
			auto &m = *i;
			range r;
			r.start = std::stoll(m[1].str(), 0, 16);
			r.end = std::stoll(m[2].str(), 0, 16);
			r.is_readable = (m[3].str() == "r");
			r.is_writeable = (m[4].str() == "w");
			r.is_executable = (m[5].str() == "x");
			r.file_name = m[6].str();
			ret->ranges.push_back(r);
		}
	}
	// Add the kernel range at the end
	range r;
	r.start = 0xffffffff00000000ULL;
	r.end = 0xffffffffffffffffULL;
	r.file_name = "kernel";
	r.is_readable = true;
	r.is_writeable = false;
	r.is_executable = true;
	ret->ranges.push_back(r);
	return ret;
}

cheri::addressmap::~addressmap() {}