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, (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 = get_variable_from_expr(arg, NULL);
  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         name = get_variable_from_expr(arg, NULL);
  38         sm_msg("error: doing dma on the stack (%s)", name);
  39         free_string(name);
  40 }
  41
  42 static void register_funcs_from_file(void)
  43 {
  44         struct token *token;
  45         const char *func;
  46         int arg;
  47
  48         token = get_tokens_file("kernel.dma_funcs");
  49         if (!token)
  50                 return;
  51         if (token_type(token) != TOKEN_STREAMBEGIN)
  52                 return;
  53         token = token->next;
  54         while (token_type(token) != TOKEN_STREAMEND) {
  55                 if (token_type(token) != TOKEN_IDENT)
  56                         return;
  57                 func = show_ident(token->ident);
  58                 token = token->next;
  59                 if (token_type(token) != TOKEN_NUMBER)
  60                         return;
  61                 arg = atoi(token->number);
  62                 add_function_hook(func, &match_dma_func, INT_PTR(arg));
  63                 token = token->next;
  64         }
  65         clear_token_alloc();
  66 }
  67
  68 void check_dma_on_stack(int id)
  69 {
  70         if (option_project != PROJ_KERNEL)
  71                 return;
  72         my_id = id;
  73         register_funcs_from_file();
  74 }