check_release_resource.c

   1 /*
   2  * smatch/check_release_resource.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * I found a bug where someone released the wrong resource and wanted to
  12  * prevent that from happening again.
  13  *
  14  */
  15
  16 #include "smatch.h"
  17
  18 static int my_id;
  19
  20 static struct tracker_list *resource_list;
  21
  22 static void match_request(const char *fn, struct expression *expr, void *_arg_no)
  23 {
  24         struct expression *arg_expr;
  25         int arg_no = PTR_INT(_arg_no);
  26         char *name;
  27         struct symbol *sym;
  28
  29         arg_expr = get_argument_from_call_expr(expr->args, arg_no);
  30         arg_expr = strip_expr(arg_expr);
  31
  32         name = get_variable_from_expr(arg_expr, &sym);
  33         if (!name || !sym)
  34                 goto free;
  35         add_tracker(&resource_list, my_id, name, sym);
  36 free:
  37         free_string(name);
  38 }
  39
  40 static void match_release(const char *fn, struct expression *expr, void *_arg_no)
  41 {
  42         struct expression *arg_expr;
  43         int arg_no = PTR_INT(_arg_no);
  44         char *name;
  45         struct symbol *sym;
  46
  47         arg_expr = get_argument_from_call_expr(expr->args, arg_no);
  48         arg_expr = strip_expr(arg_expr);
  49
  50         if (!resource_list)
  51                 return;
  52
  53         name = get_variable_from_expr(arg_expr, &sym);
  54         if (!name || !sym)
  55                 goto free;
  56         if (in_tracker_list(resource_list, my_id, name, sym))
  57                 goto free;
  58         sm_msg("warn: '%s' was not one of the resources you requested", name);
  59 free:
  60         free_string(name);
  61 }
  62
  63 static void match_end_func(struct symbol *sym)
  64 {
  65         free_trackers_and_list(&resource_list);
  66 }
  67
  68 void check_release_resource(int id)
  69 {
  70         my_id = id;
  71
  72         if (option_project != PROJ_KERNEL)
  73                 return;
  74
  75         add_function_hook("request_resource", &match_request, (void *)1);
  76         add_function_hook("release_resource", &match_release, (void *)0);
  77         add_function_hook("request_mem_resource", &match_request, (void *)0);
  78         add_function_hook("release_mem_resource", &match_release, (void *)0);
  79         add_hook(&match_end_func, END_FUNC_HOOK);
  80 }