check_type.c

   1 /*
   2  * sparse/check_type.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include "smatch.h"
  11
  12 static int my_id;
  13
  14 static int in_function(const char *fn)
  15 {
  16         char *cur_func = get_function();
  17
  18         if (!cur_func)
  19                 return 0;
  20         if (!strcmp(cur_func, fn))
  21                 return 1;
  22         return 0;
  23 }
  24
  25 static void match_free(const char *fn, struct expression *expr, void *data)
  26 {
  27         struct expression *arg_expr;
  28         char *name;
  29         struct symbol *type;
  30
  31         arg_expr = get_argument_from_call_expr(expr->args, 0);
  32         type = get_type(arg_expr);
  33
  34         if (!type || (type->type != SYM_PTR && type->type != SYM_ARRAY))
  35                 return;
  36         type = get_base_type(type);
  37
  38         if (!type || !type->ident)
  39                 return;
  40
  41         name = get_variable_from_expr_complex(arg_expr, NULL);
  42
  43         if (!strcmp("sk_buff", type->ident->name)) {
  44                 sm_msg("error: use kfree_skb() here instead of kfree(%s)", name);
  45         } else if (!strcmp("net_device", type->ident->name)) {
  46                 if (in_function("alloc_netdev"))
  47                         return;
  48                 if (in_function("alloc_netdev_mqs"))
  49                         return;
  50                 sm_msg("error: use free_netdev() here instead of kfree(%s)", name);
  51         }
  52
  53         free_string(name);
  54 }
  55
  56 void check_type(int id)
  57 {
  58         my_id = id;
  59         if (option_project == PROJ_KERNEL)
  60                 add_function_hook("kfree", &match_free, NULL);
  61 }