fail/core/experiments/weathermonitor/campaign.cc

#include <iostream>
#include <vector>
#include <map>

#include "campaign.hpp"
#include "experimentInfo.hpp"
#include "controller/CampaignManager.hpp"
#include "util/Logger.hpp"
#include "util/MemoryMap.hpp"

#include "vptr_map.hpp"

#include "plugins/tracing/TracingPlugin.hpp"

using namespace fi;
using std::endl;

char const * const trace_filename = "trace.pb";
char const * const results_filename = "weathermonitor.csv";

// equivalence class type: addr, [i1, i2]
// addr: byte to inject a bit-flip into
// [i1, i2]: interval of instruction numbers, counted from experiment
//           begin
struct equivalence_class {
	sal::address_t data_address;
	int instr1, instr2;
	sal::address_t instr2_absolute;
};

bool WeathermonitorCampaign::run()
{
	Logger log("Weathermonitor Campaign");

	// non-destructive: due to the CSV header we can always manually recover
	// from an accident (append mode)
	ofstream results(results_filename, ios::out | ios::app);
	if (!results.is_open()) {
		log << "failed to open " << results_filename << endl;
		return false;
	}

	log << "startup" << endl;

	// load trace
	log << "loading trace ..." << endl;
	ifstream tracef(trace_filename);
	if (tracef.fail()) {
		log << "couldn't open " << trace_filename << endl;
		return false;
	}
	Trace trace;
	trace.ParseFromIstream(&tracef);
	tracef.close();
	log << "... done." << endl;

	// a map of FI data addresses
	MemoryMap mm;
	mm.add(WEATHER_DATA_START, WEATHER_DATA_END - WEATHER_DATA_START);

	// set of equivalence classes that need one (rather: eight, one for
	// each bit in that byte) experiment to determine them all
	std::vector<equivalence_class> ecs_need_experiment;
	// set of equivalence classes that need no experiment, because we know
	// they'd be identical to the golden run
	std::vector<equivalence_class> ecs_no_effect;

	equivalence_class current_ec;

	// map for efficient access when results come in
	std::map<WeathermonitorExperimentData *, unsigned> experiment_ecs;
	// experiment count
	int count = 0;

	// XXX do it the other way around: iterate over trace, search addresses
	//   -> one "open" EC for every address
	// for every injection address ...
	for (MemoryMap::iterator it = mm.begin(); it != mm.end(); ++it) {
		std::cerr << ".";
		sal::address_t data_address = *it;
		current_ec.instr1 = 0;
		int instr = 0;
		sal::address_t instr_absolute = 0; // FIXME this one probably should also be recorded ...
		Trace_Event const *ev;

		// for every section in the trace between subsequent memory
		// accesses to that address ...
		for (int eventnr = 0; eventnr < trace.event_size(); ++eventnr) {
			ev = &trace.event(eventnr);

			// instruction events just get counted
			if (!ev->has_memaddr()) {
				// new instruction
				instr++;
				instr_absolute = ev->ip();
				continue;

			// skip accesses to other data
			// FIXME again, do it the other way around, and use mm.isMatching()!
			} else if (ev->memaddr() + ev->width() <= data_address
			        || ev->memaddr() > data_address) {
				continue;

			// skip zero-sized intervals: these can
			// occur when an instruction accesses a
			// memory location more than once
			// (e.g., INC, CMPXCHG)
			} else if (current_ec.instr1 > instr) {
				continue;
			}

			// we now have an interval-terminating R/W
			// event to the memaddr we're currently looking
			// at:

			// complete the equivalence interval
			current_ec.instr2 = instr;
			current_ec.instr2_absolute = instr_absolute;
			current_ec.data_address = data_address;

			if (ev->accesstype() == ev->READ) {
				// a sequence ending with READ: we need
				// to do one experiment to cover it
				// completely
				ecs_need_experiment.push_back(current_ec);

				// instantly enqueue job: that way the job clients can already
				// start working in parallel
				WeathermonitorExperimentData *d = new WeathermonitorExperimentData;
				// we pick the rightmost instruction in that interval
				d->msg.set_instr_offset(current_ec.instr2);
				d->msg.set_instr_address(current_ec.instr2_absolute);
				d->msg.set_mem_addr(current_ec.data_address);

				// store index into ecs_need_experiment
				experiment_ecs[d] = ecs_need_experiment.size() - 1;

				fi::campaignmanager.addParam(d);
				++count;
			} else if (ev->accesstype() == ev->WRITE) {
				// a sequence ending with WRITE: an
				// injection anywhere here would have
				// no effect.
				ecs_no_effect.push_back(current_ec);
			} else {
				log << "WAT" << endl;
			}

			// next interval must start at next
			// instruction; the aforementioned
			// skipping mechanism wouldn't work
			// otherwise
			current_ec.instr1 = instr + 1;
		}

		// close the last interval:
		// Why -1?  In most cases it does not make sense to inject before the
		// very last instruction, as we won't execute it anymore.  This *only*
		// makes sense if we also inject into parts of the result vector.  This
		// is not the case in this experiment, and with -1 we'll get a
		// result comparable to the non-pruned campaign.
		// XXX still true for weathermonitor?
		current_ec.instr2 = instr - 1;
		current_ec.instr2_absolute = 0; // won't be used
		current_ec.data_address = data_address;
		// zero-sized?  skip.
		if (current_ec.instr1 > current_ec.instr2) {
			continue;
		}
		// as the experiment ends, this byte is a "don't care":
		ecs_no_effect.push_back(current_ec);
	}

	fi::campaignmanager.noMoreParameters();
	log << "done enqueueing parameter sets (" << count << ")." << endl;

	log << "equivalence classes generated:"
	    << " need_experiment = " << ecs_need_experiment.size()
	    << " no_effect = " << ecs_no_effect.size() << endl;

	// statistics
	unsigned long num_dumb_experiments = 0;
	for (std::vector<equivalence_class>::const_iterator it = ecs_need_experiment.begin();
	     it != ecs_need_experiment.end(); ++it) {
		num_dumb_experiments += (*it).instr2 - (*it).instr1 + 1;
	}
	for (std::vector<equivalence_class>::const_iterator it = ecs_no_effect.begin();
	     it != ecs_no_effect.end(); ++it) {
		num_dumb_experiments += (*it).instr2 - (*it).instr1 + 1;
	}
	log << "pruning: reduced " << num_dumb_experiments * 8 <<
	       " experiments to " << ecs_need_experiment.size() * 8 << endl;


	return true;
}