check_dma_on_stack.c

   1 /*
   2  * sparse/check_dma_on_stack.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 void match_dma_func(const char *fn, struct expression *expr, void *param)
  15 {
  16         struct expression *arg;
  17         struct symbol *sym;
  18         char *name;
  19
  20         arg = get_argument_from_call_expr(expr->args, PTR_INT(param));
  21         arg = strip_expr(arg);
  22         if (!arg)
  23                 return;
  24         if (arg->type == EXPR_PREOP && arg->op == '&') {
  25                 if (arg->unop->type != EXPR_SYMBOL)
  26                         return;
  27                 name = expr_to_str(arg);
  28                 sm_msg("error: doing dma on the stack (%s)", name);
  29                 free_string(name);
  30                 return;
  31         }
  32         if (arg->type != EXPR_SYMBOL)
  33                 return;
  34         sym = get_type(arg);
  35         if (!sym || sym->type != SYM_ARRAY)
  36                 return;
  37         if (get_param_num(arg) >= 0)
  38                 return;
  39         name = expr_to_var(arg);
  40         sm_msg("error: doing dma on the stack (%s)", name);
  41         free_string(name);
  42 }
  43
  44 static void register_funcs_from_file(void)
  45 {
  46         struct token *token;
  47         const char *func;
  48         int arg;
  49
  50         token = get_tokens_file("kernel.dma_funcs");
  51         if (!token)
  52                 return;
  53         if (token_type(token) != TOKEN_STREAMBEGIN)
  54                 return;
  55         token = token->next;
  56         while (token_type(token) != TOKEN_STREAMEND) {
  57                 if (token_type(token) != TOKEN_IDENT)
  58                         return;
  59                 func = show_ident(token->ident);
  60                 token = token->next;
  61                 if (token_type(token) != TOKEN_NUMBER)
  62                         return;
  63                 arg = atoi(token->number);
  64                 add_function_hook(func, &match_dma_func, INT_PTR(arg));
  65                 token = token->next;
  66         }
  67         clear_token_alloc();
  68 }
  69
  70 void check_dma_on_stack(int id)
  71 {
  72         if (option_project != PROJ_KERNEL)
  73                 return;
  74         my_id = id;
  75         register_funcs_from_file();
  76 }