smatch: check libld_* allocation functions

          --- old/usr/src/tools/smatch/src/check_frees_param.c
          +++ new/usr/src/tools/smatch/src/check_frees_param.c

   1    1  /*
   2    2   * Copyright (C) 2014 Oracle.
   3    3   *
   4    4   * This program is free software; you can redistribute it and/or
   5    5   * modify it under the terms of the GNU General Public License
   6    6   * as published by the Free Software Foundation; either version 2
   7    7   * of the License, or (at your option) any later version.
   8    8   *
   9    9   * This program is distributed in the hope that it will be useful,
  10   10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11   11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12   12   * GNU General Public License for more details.
  13   13   *
  14   14   * You should have received a copy of the GNU General Public License
  15   15   * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16   16   */
  17   17  
  18   18  /*
  19   19   * This file is sort of like check_dereferences_param.c.  In theory the one
  20   20   * difference should be that the param is NULL it should still be counted as a
  21   21   * free.  But for now I don't handle that case.
  22   22   */
  23   23  
  24   24  #include "smatch.h"
  25   25  #include "smatch_extra.h"
  26   26  #include "smatch_slist.h"
  27   27  
  28   28  static int my_id;
  29   29  
  30   30  STATE(freed);
  31   31  STATE(ignore);
  32   32  STATE(param);
  33   33  
  34   34  static void set_ignore(struct sm_state *sm, struct expression *mod_expr)
  35   35  {
  36   36          set_state(my_id, sm->name, sm->sym, &ignore);
  37   37  }
  38   38  
  39   39  static void match_function_def(struct symbol *sym)
  40   40  {
  41   41          struct symbol *arg;
  42   42          int i;
  43   43  
  44   44          i = -1;
  45   45          FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
  46   46                  i++;
  47   47                  if (!arg->ident)
  48   48                          continue;
  49   49                  set_state(my_id, arg->ident->name, arg, &param);
  50   50          } END_FOR_EACH_PTR(arg);
  51   51  }
  52   52  
  53   53  static void freed_variable(struct expression *expr)
  54   54  {
  55   55          struct sm_state *sm;
  56   56  
  57   57          expr = strip_expr(expr);
  58   58          if (get_param_num(expr) < 0)
  59   59                  return;
  60   60  
  61   61          sm = get_sm_state_expr(my_id, expr);
  62   62          if (sm && slist_has_state(sm->possible, &ignore))
  63   63                  return;
  64   64          set_state_expr(my_id, expr, &freed);
  65   65  }
  66   66  
  67   67  static void match_free(const char *fn, struct expression *expr, void *param)
  68   68  {
  69   69          struct expression *arg;
  70   70  
  71   71          arg = get_argument_from_call_expr(expr->args, PTR_INT(param));
  72   72          if (!arg)
  73   73                  return;
  74   74          freed_variable(arg);
  75   75  }
  76   76  
  77   77  static void set_param_freed(struct expression *call, struct expression *arg, char *key, char *unused)
  78   78  {
  79   79          /* XXX FIXME: return_implies has been updated with more information */
  80   80          if (strcmp(key, "$") != 0)
  81   81                  return;
  82   82          freed_variable(arg);
  83   83  }
  84   84  
  85   85  static void process_states(void)
  86   86  {
  87   87          struct sm_state *sm;
  88   88          int param;
  89   89          const char *param_name;
  90   90  
  91   91          FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) {
  92   92                  if (sm->state != &freed)
  93   93                          continue;
  94   94                  param = get_param_num_from_sym(sm->sym);
  95   95                  if (param < 0)
  96   96                          continue;
  97   97                  param_name = get_param_name(sm);
  98   98                  if (!param_name)
  99   99                          continue;
 100  100                  sql_insert_return_implies(PARAM_FREED, param, param_name, "1");
 101  101          } END_FOR_EACH_SM(sm);
 102  102  
 103  103  }
 104  104  
 105  105  void check_frees_param(int id)
 106  106  {

 107  107          my_id = id;
 108  108  
 109  109          if (option_project == PROJ_KERNEL) {
 110  110                  /* The kernel uses check_frees_param_strict.c */
 111  111                  return;
 112  112          }
 113  113  
 114  114          add_hook(&match_function_def, FUNC_DEF_HOOK);
 115  115  
 116  116          add_function_hook("free", &match_free, INT_PTR(0));
      117 +        if (option_project == PROJ_ILLUMOS_USER)
      118 +                add_function_hook("libld_free", &match_free, INT_PTR(0));
 117  119  
 118  120          select_return_implies_hook(PARAM_FREED, &set_param_freed);
 119  121          add_modification_hook(my_id, &set_ignore);
 120  122  
 121  123          all_return_states_hook(&process_states);
 122  124  }
    

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