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 extern int check_assigned_expr_id;
  22
  23 static int is_probably_ok(struct expression *expr)
  24 {
  25         expr = strip_expr(expr);
  26
  27         if (expr->type == EXPR_BINOP)
  28                 return 1;
  29         if (expr->type == EXPR_SIZEOF)
  30                 return 1;
  31
  32         return 0;
  33 }
  34
  35 static void verify_size_expr(struct expression *expr)
  36 {
  37         if (expr->type != EXPR_BINOP)
  38                 return;
  39         if (expr->op != '-')
  40                 return;
  41         if (is_probably_ok(expr->left))
  42                 return;
  43         if (is_probably_ok(expr->right))
  44                 return;
  45         sm_msg("warn: consider using resource_size() here");
  46 }
  47
  48 static void handle_assigned_expr(struct expression *expr)
  49 {
  50         struct smatch_state *state;
  51
  52         state = get_state_expr(check_assigned_expr_id, expr);
  53         if (!state || !state->data)
  54                 return;
  55         expr = (struct expression *)state->data;
  56         verify_size_expr(expr);
  57 }
  58
  59 static void match_resource(const char *fn, struct expression *expr, void *_arg_no)
  60 {
  61         struct expression *arg_expr;
  62         int arg_no = PTR_INT(_arg_no);
  63
  64         arg_expr = get_argument_from_call_expr(expr->args, arg_no);
  65         arg_expr = strip_expr(arg_expr);
  66         if (!arg_expr)
  67                 return;
  68
  69         if (arg_expr->type == EXPR_SYMBOL) {
  70                 handle_assigned_expr(arg_expr);
  71                 return;
  72         }
  73         verify_size_expr(arg_expr);
  74 }
  75
  76 void check_resource_size(int id)
  77 {
  78         my_id = id;
  79
  80         if (option_project != PROJ_KERNEL)
  81                 return;
  82
  83         add_function_hook("ioremap_nocache", &match_resource, (void *)1);
  84         add_function_hook("ioremap", &match_resource, (void *)1);
  85         add_function_hook("__request_region", &match_resource, (void *)2);
  86         add_function_hook("__release_region", &match_resource, (void *)2);
  87         add_function_hook("__devm_request_region", &match_resource, (void *)3);
  88         add_function_hook("__devm_release_region", &match_resource, (void *)3);
  89 }