newfuzzer.cc

   1 #include "newfuzzer.h"
   2 #include "threads-model.h"
   3 #include "model.h"
   4 #include "action.h"
   5 #include "execution.h"
   6 #include "funcnode.h"
   7
   8 typedef HashTable<FuncInst *, ModelAction *, uintptr_t, 0> inst_act_map_t;
   9
  10 NewFuzzer::NewFuzzer() :
  11         thrd_last_read_act(),
  12         thrd_curr_pred(),
  13         thrd_selected_child_branch()
  14 {}
  15
  16 /**
  17  * @brief Register the ModelHistory and ModelExecution engine
  18  */
  19 void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *execution)
  20 {
  21         this->history = history;
  22         this->execution = execution;
  23 }
  24
  25 int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set)
  26 {
  27         int random_index = random() % rf_set->size();
  28
  29         thread_id_t tid = read->get_tid();
  30         int thread_id = id_to_int(tid);
  31
  32         if (thrd_last_read_act.size() <= (uint) thread_id)
  33                 thrd_last_read_act.resize(thread_id + 1);
  34
  35         SnapVector<func_id_list_t> * thrd_func_list = execution->get_thrd_func_list();
  36         uint32_t func_id = (*thrd_func_list)[thread_id].back();
  37         FuncNode * func_node = history->get_func_node(func_id);
  38         inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
  39
  40         // A new read action is encountered, select a random child branch of current predicate
  41         if (read != thrd_last_read_act[thread_id]) {
  42                 thrd_last_read_act[thread_id] = read;
  43
  44                 FuncInst * read_inst = func_node->get_inst(read);
  45                 Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
  46                 selectBranch(thread_id, curr_pred, read_inst);
  47         }
  48
  49         Predicate * selected_branch = thrd_selected_child_branch[thread_id];
  50         if (selected_branch == NULL)
  51                 return random_index;
  52
  53         PredExprSet * pred_expressions = selected_branch->get_pred_expressions();
  54
  55 //      FuncInst * read_inst = selected_branch->get_func_inst();
  56 //      model_print("thread %d ", tid);
  57 //      read_inst->print();
  58
  59         // unset predicates
  60         if (pred_expressions->getSize() == 0)
  61                 return random_index;
  62
  63         for (uint index = 0; index < rf_set->size(); index++) {
  64                 ModelAction * write_act = (*rf_set)[index];
  65                 bool satisfy_predicate = true;
  66
  67                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
  68                 while (pred_expr_it->hasNext()) {
  69                         struct pred_expr * expression = pred_expr_it->next();
  70                         uint64_t last_read, write_val;
  71                         bool equality;
  72
  73                         if (expression->token == NOPREDICATE)
  74                                 return random_index;
  75
  76                         switch(expression->token) {
  77                                 case EQUALITY:
  78                                         FuncInst * to_be_compared;
  79                                         ModelAction * last_act;
  80
  81                                         to_be_compared = expression->func_inst;
  82                                         last_act = inst_act_map->get(to_be_compared);
  83
  84                                         last_read = last_act->get_reads_from_value();
  85                                         write_val = write_act->get_write_value();
  86
  87                                         equality = (last_read == write_val);
  88                                         if (equality != expression->value)
  89                                                 satisfy_predicate = false;
  90
  91                                         model_print("equality predicate\n");
  92                                         break;
  93                                 case NULLITY:
  94                                         model_print("nullity predicate, under construction\n");
  95                                         break;
  96                                 default:
  97                                         model_print("unknown predicate token\n");
  98                                         break;
  99                         }
 100
 101                         if (!satisfy_predicate)
 102                                 break;
 103                 }
 104
 105                 /* TODO: collect all writes that satisfy predicate; if some of them violate
 106                  * modification graph, others can be chosen */
 107                 if (satisfy_predicate) {
 108                         model_print("^_^ satisfy predicate\n");
 109                         return index;
 110                 }
 111         }
 112
 113         // TODO: make this thread sleep if no write satisfies the chosen predicate
 114         return random_index;
 115 }
 116
 117 void NewFuzzer::selectBranch(int thread_id, Predicate * curr_pred, FuncInst * read_inst)
 118 {
 119         if ( thrd_selected_child_branch.size() <= (uint) thread_id)
 120                 thrd_selected_child_branch.resize(thread_id + 1);
 121
 122         if (curr_pred == NULL || read_inst == NULL) {
 123                 thrd_selected_child_branch[thread_id] = NULL;
 124                 return;
 125         }
 126
 127         ModelVector<Predicate *> * children = curr_pred->get_children();
 128         SnapVector<Predicate *> branches;
 129
 130         for (uint i = 0; i < children->size(); i++) {
 131                 Predicate * child = (*children)[i];
 132                 if (child->get_func_inst() == read_inst)
 133                         branches.push_back(child);
 134         }
 135
 136         // predicate children have not been generated
 137         if (branches.size() == 0) {
 138                 thrd_selected_child_branch[thread_id] = NULL;
 139                 return;
 140         }
 141
 142         // randomly select a branch
 143         int random_index = random() % branches.size();
 144         Predicate * random_branch = branches[ random_index ];
 145         thrd_selected_child_branch[thread_id] = random_branch;
 146 }
 147
 148 Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
 149 {
 150         int thread_id = id_to_int(tid);
 151         if (thrd_selected_child_branch.size() <= (uint) thread_id)
 152                 return NULL;
 153
 154         return thrd_selected_child_branch[thread_id];
 155 }