check_frees_argument.c

   1 /*
   2  * sparse/check_frees_argument.c
   3  *
   4  * Copyright (C) 2009 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * This script is for finding functions like hcd_buffer_free() which free
  12  * their arguments.  After running it, add those functions to check_memory.c
  13  */
  14
  15 #include "smatch.h"
  16
  17 static int my_id;
  18
  19 static struct symbol *this_func;
  20
  21 static void match_function_def(struct symbol *sym)
  22 {
  23         this_func = sym;
  24 }
  25
  26 static void print_if_arg(char *name, struct symbol *sym)
  27 {
  28         struct symbol *arg;
  29         const char *arg_name;
  30         int i = 0;
  31
  32         FOR_EACH_PTR(this_func->ctype.base_type->arguments, arg) {
  33                 arg_name = (arg->ident?arg->ident->name:"-");
  34                 if (sym == arg && !strcmp(name, arg_name))
  35                         smatch_msg("info: frees argument %d", i);
  36                 i++;
  37         } END_FOR_EACH_PTR(arg);
  38 }
  39
  40 static void match_call(struct expression *expr)
  41 {
  42         char *fn_name;
  43         struct expression *tmp;
  44         struct symbol *sym;
  45         char *name;
  46
  47         fn_name = get_variable_from_expr(expr->fn, NULL);
  48         if (!fn_name || strcmp(fn_name, "kfree"))
  49                 goto free;
  50
  51         FOR_EACH_PTR(expr->args, tmp) {
  52                 tmp = strip_expr(tmp);
  53                 name = get_variable_from_expr(tmp, &sym);
  54                 print_if_arg(name, sym);
  55                 free_string(name);
  56         } END_FOR_EACH_PTR(tmp);
  57 free:
  58         free_string(fn_name);
  59 }
  60
  61 void register_frees_argument(int id)
  62 {
  63         my_id = id;
  64         add_hook(&match_function_def, FUNC_DEF_HOOK);
  65         add_hook(&match_call, FUNCTION_CALL_HOOK);
  66 }