Пример #1
0
std::string
NoOperation::StateNormalizer::toString(const BaseSemantics::DispatcherPtr &cpu, const BaseSemantics::StatePtr &state_) {
    BaseSemantics::StatePtr state = state_;
    BaseSemantics::RiscOperatorsPtr ops = cpu->get_operators();
    if (!state)
        return "";
    bool isCloned = false;                              // do we have our own copy of the state?

    // If possible and appropriate, remove the instruction pointer register
    const RegisterDescriptor regIp = cpu->instructionPointerRegister();
    BaseSemantics::RegisterStateGenericPtr rstate = BaseSemantics::RegisterStateGeneric::promote(state->registerState());
    if (rstate && rstate->is_partly_stored(regIp)) {
        BaseSemantics::SValuePtr ip = ops->readRegister(cpu->instructionPointerRegister());
        if (ip->is_number()) {
            state = state->clone();
            isCloned = true;
            rstate = BaseSemantics::RegisterStateGeneric::promote(state->registerState());
            rstate->erase_register(regIp, ops.get());
        }
    }

    // Get the memory state, cloning the state if not done so above.
    BaseSemantics::MemoryCellStatePtr mem =
        boost::dynamic_pointer_cast<BaseSemantics::MemoryCellState>(state->memoryState());
    if (mem && !isCloned) {
        state = state->clone();
        isCloned = true;
        mem = BaseSemantics::MemoryCellState::promote(state->memoryState());
    }

    // Erase memory that has never been written (i.e., cells that sprang into existence by reading an address) of which appears
    // to have been recently popped from the stack.
    CellErasurePredicate predicate(ops, ops->readRegister(cpu->stackPointerRegister()), ignorePoppedMemory_);
    if (mem)
        mem->eraseMatchingCells(predicate);

    BaseSemantics::Formatter fmt;
    fmt.set_show_latest_writers(false);
    fmt.set_show_properties(false);
    std::ostringstream ss;
    ss <<(*state+fmt);
    return ss.str();
}
Пример #2
0
/* Analyze a single interpretation a block at a time */
static void
analyze_interp(SgAsmInterpretation *interp)
{
    /* Get the set of all instructions except instructions that are part of left-over blocks. */
    struct AllInstructions: public SgSimpleProcessing, public std::map<rose_addr_t, SgAsmX86Instruction*> {
        void visit(SgNode *node) {
            SgAsmX86Instruction *insn = isSgAsmX86Instruction(node);
            SgAsmFunction *func = SageInterface::getEnclosingNode<SgAsmFunction>(insn);
            if (func && 0==(func->get_reason() & SgAsmFunction::FUNC_LEFTOVERS))
                insert(std::make_pair(insn->get_address(), insn));
        }
    } insns;
    insns.traverse(interp, postorder);

    while (!insns.empty()) {
        std::cout <<"=====================================================================================\n"
                  <<"=== Starting a new basic block                                                    ===\n"
                  <<"=====================================================================================\n";
        AllInstructions::iterator si = insns.begin();
        SgAsmX86Instruction *insn = si->second;
        insns.erase(si);

        BaseSemantics::RiscOperatorsPtr operators = make_ops();
        BaseSemantics::Formatter formatter;
        formatter.set_suppress_initial_values();
        formatter.set_show_latest_writers(do_usedef);
        BaseSemantics::DispatcherPtr dispatcher;
        if (do_trace) {
            // Enable RiscOperators tracing, but turn off a bunch of info that makes comparisons with a known good answer
            // difficult.
            Sawyer::Message::PrefixPtr prefix = Sawyer::Message::Prefix::instance();
            prefix->showProgramName(false);
            prefix->showThreadId(false);
            prefix->showElapsedTime(false);
            prefix->showFacilityName(Sawyer::Message::Prefix::NEVER);
            prefix->showImportance(false);
            Sawyer::Message::UnformattedSinkPtr sink = Sawyer::Message::StreamSink::instance(std::cout);
            sink->prefix(prefix);
            sink->defaultPropertiesNS().useColor = false;
            TraceSemantics::RiscOperatorsPtr trace = TraceSemantics::RiscOperators::instance(operators);
            trace->stream().destination(sink);
            trace->stream().enable();
            dispatcher = DispatcherX86::instance(trace, 32);
        } else {
            dispatcher = DispatcherX86::instance(operators, 32);
        }
        operators->set_solver(make_solver());

        // The fpstatus_top register must have a concrete value if we'll use the x86 floating-point stack (e.g., st(0))
        if (const RegisterDescriptor *REG_FPSTATUS_TOP = regdict->lookup("fpstatus_top")) {
            BaseSemantics::SValuePtr st_top = operators->number_(REG_FPSTATUS_TOP->get_nbits(), 0);
            operators->writeRegister(*REG_FPSTATUS_TOP, st_top);
        }

#if SEMANTIC_DOMAIN == SYMBOLIC_DOMAIN
        BaseSemantics::SValuePtr orig_esp;
        if (do_test_subst) {
            // Only request the orig_esp if we're going to use it later because it causes an esp value to be instantiated
            // in the state, which is printed in the output, and thus changes the answer.
            BaseSemantics::RegisterStateGeneric::promote(operators->get_state()->get_register_state())->initialize_large();
            orig_esp = operators->readRegister(*regdict->lookup("esp"));
            std::cout <<"Original state:\n" <<*operators;
        }
#endif

        /* Perform semantic analysis for each instruction in this block. The block ends when we no longer know the value of
         * the instruction pointer or the instruction pointer refers to an instruction that doesn't exist or which has already
         * been processed. */
        while (1) {
            /* Analyze current instruction */
            std::cout <<"\n" <<unparseInstructionWithAddress(insn) <<"\n";
            try {
                dispatcher->processInstruction(insn);
#   if 0 /*DEBUGGING [Robb P. Matzke 2013-05-01]*/
                show_state(operators); // for comparing RegisterStateGeneric with the old RegisterStateX86 output
#   else
                std::cout <<(*operators + formatter);
#   endif
            } catch (const BaseSemantics::Exception &e) {
                std::cout <<e <<"\n";
            }

            /* Never follow CALL instructions */
            if (insn->get_kind()==x86_call || insn->get_kind()==x86_farcall)
                break;

            /* Get next instruction of this block */
            BaseSemantics::SValuePtr ip = operators->readRegister(dispatcher->findRegister("eip"));
            if (!ip->is_number())
                break;
            rose_addr_t next_addr = ip->get_number();
            si = insns.find(next_addr);
            if (si==insns.end()) break;
            insn = si->second;
            insns.erase(si);
        }

        // Test substitution on the symbolic state.
#if SEMANTIC_DOMAIN == SYMBOLIC_DOMAIN
        if (do_test_subst) {
            SymbolicSemantics::SValuePtr from = SymbolicSemantics::SValue::promote(orig_esp);
            BaseSemantics::SValuePtr newvar = operators->undefined_(32);
            newvar->set_comment("frame_pointer");
            SymbolicSemantics::SValuePtr to =
                SymbolicSemantics::SValue::promote(operators->add(newvar, operators->number_(32, 4)));
            std::cout <<"Substituting from " <<*from <<" to " <<*to <<"\n";
            SymbolicSemantics::RiscOperators::promote(operators)->substitute(from, to);
            std::cout <<"Substituted state:\n" <<(*operators+formatter);
        }
#endif
    }
}