check_release_resource.c

   1 /*
   2  * Copyright (C) 2010 Dan Carpenter.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 /*
  19  * I found a bug where someone released the wrong resource and wanted to
  20  * prevent that from happening again.
  21  *
  22  */
  23
  24 #include "smatch.h"
  25
  26 static int my_id;
  27
  28 static struct tracker_list *resource_list;
  29
  30 static void match_request(const char *fn, struct expression *expr, void *_arg_no)
  31 {
  32         struct expression *arg_expr;
  33         int arg_no = PTR_INT(_arg_no);
  34         char *name;
  35         struct symbol *sym;
  36
  37         arg_expr = get_argument_from_call_expr(expr->args, arg_no);
  38         arg_expr = strip_expr(arg_expr);
  39
  40         name = expr_to_var_sym(arg_expr, &sym);
  41         if (!name || !sym)
  42                 goto free;
  43         add_tracker(&resource_list, my_id, name, sym);
  44 free:
  45         free_string(name);
  46 }
  47
  48 static void match_release(const char *fn, struct expression *expr, void *_arg_no)
  49 {
  50         struct expression *arg_expr;
  51         int arg_no = PTR_INT(_arg_no);
  52         char *name;
  53         struct symbol *sym;
  54
  55         arg_expr = get_argument_from_call_expr(expr->args, arg_no);
  56         arg_expr = strip_expr(arg_expr);
  57
  58         if (!resource_list)
  59                 return;
  60
  61         name = expr_to_var_sym(arg_expr, &sym);
  62         if (!name || !sym)
  63                 goto free;
  64         if (in_tracker_list(resource_list, my_id, name, sym))
  65                 goto free;
  66         sm_warning("'%s' was not one of the resources you requested", name);
  67 free:
  68         free_string(name);
  69 }
  70
  71 static void match_end_func(struct symbol *sym)
  72 {
  73         if (__inline_fn)
  74                 return;
  75         free_trackers_and_list(&resource_list);
  76 }
  77
  78 void check_release_resource(int id)
  79 {
  80         my_id = id;
  81
  82         if (option_project != PROJ_KERNEL)
  83                 return;
  84
  85         add_function_hook("request_resource", &match_request, INT_PTR(1));
  86         add_function_hook("allocate_resource", &match_request, INT_PTR(1));
  87         add_function_hook("release_resource", &match_release, INT_PTR(0));
  88         add_hook(&match_end_func, END_FUNC_HOOK);
  89 }