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 extern int check_assigned_expr_id;
  23
  24 static int is_kmalloc_call(struct expression *expr)
  25 {
  26         if (expr->type != EXPR_CALL)
  27                 return 0;
  28         if (expr->fn->type != EXPR_SYMBOL)
  29                 return 0;
  30         if (!strcmp(expr->fn->symbol_name->name, "kmalloc"))
  31                 return 1;
  32         if (!strcmp(expr->fn->symbol_name->name, "kzalloc"))
  33                 return 1;
  34         return 0;
  35 }
  36
  37 static void match_condition(struct expression *expr)
  38 {
  39         char *macro;
  40         struct smatch_state *state;
  41         struct expression *right;
  42         char *name;
  43
  44         macro = get_macro_name(expr->pos);
  45         if (!macro || strcmp(macro, "BUG_ON") != 0)
  46                 return;
  47         state = get_state_expr(check_assigned_expr_id, expr);
  48         if (!state || !state->data)
  49                 return;
  50         right = (struct expression *)state->data;
  51         if (!is_kmalloc_call(right))
  52                 return;
  53
  54         name = expr_to_var(expr);
  55         sm_msg("warn: bug on allocation failure '%s'", name);
  56         free_string(name);
  57 }
  58
  59 void check_kmalloc_to_bugon(int id)
  60 {
  61         if (option_project != PROJ_KERNEL)
  62                 return;
  63         if (!option_spammy)
  64                 return;
  65         my_id = id;
  66         add_hook(&match_condition, CONDITION_HOOK);
  67 }