check_zero_to_err_ptr.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 static int my_id;
  21
  22 static void match_err_ptr(const char *fn, struct expression *expr, void *data)
  23 {
  24         struct expression *arg_expr;
  25         sval_t sval;
  26
  27         arg_expr = get_argument_from_call_expr(expr->args, 0);
  28         if (!get_implied_value(arg_expr, &sval))
  29                 return;
  30         if (sval.value != 0)
  31                 return;
  32         sm_msg("warn: passing zero to '%s'", fn);
  33 }
  34
  35 void check_zero_to_err_ptr(int id)
  36 {
  37         if (option_project != PROJ_KERNEL)
  38                 return;
  39
  40         my_id = id;
  41         add_function_hook("ERR_PTR", &match_err_ptr, NULL);
  42         add_function_hook("ERR_CAST", &match_err_ptr, NULL);
  43         add_function_hook("PTR_ERR", &match_err_ptr, NULL);
  44 }