check_resource_size.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 #include "smatch.h"
  19
  20 static int my_id;
  21
  22 static int is_probably_ok(struct expression *expr)
  23 {
  24         expr = strip_expr(expr);
  25
  26         if (expr->type == EXPR_BINOP)
  27                 return 1;
  28         if (expr->type == EXPR_SIZEOF)
  29                 return 1;
  30
  31         return 0;
  32 }
  33
  34 static void verify_size_expr(struct expression *expr)
  35 {
  36         if (expr->type != EXPR_BINOP)
  37                 return;
  38         if (expr->op != '-')
  39                 return;
  40         if (is_probably_ok(expr->left))
  41                 return;
  42         if (is_probably_ok(expr->right))
  43                 return;
  44         sm_warning("consider using resource_size() here");
  45 }
  46
  47 static void handle_assigned_expr(struct expression *expr)
  48 {
  49         expr = get_assigned_expr(expr);
  50         if (!expr)
  51                 return;
  52         verify_size_expr(expr);
  53 }
  54
  55 static void match_resource(const char *fn, struct expression *expr, void *_arg_no)
  56 {
  57         struct expression *arg_expr;
  58         int arg_no = PTR_INT(_arg_no);
  59
  60         arg_expr = get_argument_from_call_expr(expr->args, arg_no);
  61         arg_expr = strip_expr(arg_expr);
  62         if (!arg_expr)
  63                 return;
  64
  65         if (arg_expr->type == EXPR_SYMBOL) {
  66                 handle_assigned_expr(arg_expr);
  67                 return;
  68         }
  69         verify_size_expr(arg_expr);
  70 }
  71
  72 void check_resource_size(int id)
  73 {
  74         my_id = id;
  75
  76         if (option_project != PROJ_KERNEL)
  77                 return;
  78
  79         add_function_hook("ioremap_nocache", &match_resource, (void *)1);
  80         add_function_hook("ioremap", &match_resource, (void *)1);
  81         add_function_hook("__request_region", &match_resource, (void *)2);
  82         add_function_hook("__release_region", &match_resource, (void *)2);
  83         add_function_hook("__devm_request_region", &match_resource, (void *)3);
  84         add_function_hook("__devm_release_region", &match_resource, (void *)3);
  85 }