check_kmalloc_to_bugon.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_kmalloc_call(struct expression *expr)
  23 {
  24         if (expr->type != EXPR_CALL)
  25                 return 0;
  26         if (expr->fn->type != EXPR_SYMBOL)
  27                 return 0;
  28         if (!strcmp(expr->fn->symbol_name->name, "kmalloc"))
  29                 return 1;
  30         if (!strcmp(expr->fn->symbol_name->name, "kzalloc"))
  31                 return 1;
  32         return 0;
  33 }
  34
  35 static void match_condition(struct expression *expr)
  36 {
  37         char *macro;
  38         struct expression *right;
  39         char *name;
  40
  41         macro = get_macro_name(expr->pos);
  42         if (!macro || strcmp(macro, "BUG_ON") != 0)
  43                 return;
  44         right = get_assigned_expr(expr);
  45         if (!right || !is_kmalloc_call(right))
  46                 return;
  47
  48         name = expr_to_var(expr);
  49         sm_warning("bug on allocation failure '%s'", name);
  50         free_string(name);
  51 }
  52
  53 void check_kmalloc_to_bugon(int id)
  54 {
  55         if (option_project != PROJ_KERNEL)
  56                 return;
  57         if (!option_spammy)
  58                 return;
  59         my_id = id;
  60         add_hook(&match_condition, CONDITION_HOOK);
  61 }