check_freeing_devm.c

   1 /*
   2  * Copyright (C) 2013 Oracle.
   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 STATE(devm);
  21
  22 static int my_id;
  23
  24 static void match_assign(const char *fn, struct expression *expr, void *unused)
  25 {
  26         set_state_expr(my_id, expr->left, &devm);
  27 }
  28
  29 static void match_free_func(const char *fn, struct expression *expr, void *_arg)
  30 {
  31         struct expression *arg_expr;
  32         int arg = PTR_INT(_arg);
  33         char *name;
  34
  35         arg_expr = get_argument_from_call_expr(expr->args, arg);
  36         if (!get_state_expr(my_id, arg_expr))
  37                 return;
  38         name = expr_to_str(arg_expr);
  39         sm_msg("warn: passing devm_ allocated variable to kfree. '%s'", name);
  40         free_string(name);
  41 }
  42
  43 static void register_funcs_from_file(void)
  44 {
  45         struct token *token;
  46         const char *func;
  47         int arg;
  48
  49         token = get_tokens_file("kernel.frees_argument");
  50         if (!token)
  51                 return;
  52         if (token_type(token) != TOKEN_STREAMBEGIN)
  53                 return;
  54         token = token->next;
  55         while (token_type(token) != TOKEN_STREAMEND) {
  56                 if (token_type(token) != TOKEN_IDENT)
  57                         return;
  58                 func = show_ident(token->ident);
  59                 token = token->next;
  60                 if (token_type(token) != TOKEN_NUMBER)
  61                         return;
  62                 arg = atoi(token->number);
  63                 add_function_hook(func, &match_free_func, INT_PTR(arg));
  64                 token = token->next;
  65         }
  66         clear_token_alloc();
  67 }
  68
  69 void check_freeing_devm(int id)
  70 {
  71         if (option_project != PROJ_KERNEL)
  72                 return;
  73
  74         my_id = id;
  75
  76         add_function_assign_hook("devm_kmalloc", &match_assign, NULL);
  77         add_function_assign_hook("devm_kzalloc", &match_assign, NULL);
  78         add_function_assign_hook("devm_kcalloc", &match_assign, NULL);
  79         add_function_assign_hook("devm_kmalloc_array", &match_assign, NULL);
  80
  81
  82         add_function_hook("kfree", &match_free_func, INT_PTR(0));
  83         add_function_hook("krealloc", &match_free_func, INT_PTR(0));
  84         register_funcs_from_file();
  85 }