check_kernel.c

   1 /*
   2  * sparse/check_kernel.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 /*
  11  * This is kernel specific stuff for smatch_extra.
  12  */
  13
  14 #include "smatch.h"
  15 #include "smatch_extra.h"
  16
  17 static int implied_err_cast_return(struct expression *call, void *unused, struct range_list_sval **rl)
  18 {
  19         struct expression *arg;
  20
  21         arg = get_argument_from_call_expr(call->args, 0);
  22         if (!get_implied_range_list_sval(arg, rl))
  23                 *rl = alloc_range_list_sval(ll_to_sval(-4095), ll_to_sval(-1));
  24         return 1;
  25 }
  26
  27 static int implied_copy_return(struct expression *call, void *unused, struct range_list_sval **rl)
  28 {
  29         struct expression *arg;
  30         sval_t max;
  31
  32         arg = get_argument_from_call_expr(call->args, 2);
  33         get_absolute_max_sval(arg, &max);
  34         *rl = alloc_range_list_sval(ll_to_sval(0), max);
  35         return 1;
  36 }
  37
  38 static void match_param_nonnull(const char *fn, struct expression *call_expr,
  39                         struct expression *assign_expr, void *_param)
  40 {
  41         int param = PTR_INT(_param);
  42         struct expression *arg;
  43         struct smatch_state *pre_state;
  44         struct smatch_state *true_state;
  45
  46         arg = get_argument_from_call_expr(call_expr->args, param);
  47         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  48         true_state = add_filter(pre_state, 0);
  49         set_extra_expr_nomod(arg, true_state);
  50 }
  51
  52 static void match_not_err(const char *fn, struct expression *call_expr,
  53                         struct expression *assign_expr, void *unused)
  54 {
  55         struct expression *arg;
  56         struct smatch_state *pre_state;
  57         struct smatch_state *new_state;
  58
  59         arg = get_argument_from_call_expr(call_expr->args, 0);
  60         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  61         new_state = filter_range(pre_state, whole_range.min, -1);
  62         set_extra_expr_nomod(arg, new_state);
  63 }
  64
  65 static void match_err(const char *fn, struct expression *call_expr,
  66                         struct expression *assign_expr, void *unused)
  67 {
  68         struct expression *arg;
  69         struct smatch_state *pre_state;
  70         struct smatch_state *new_state;
  71
  72         arg = get_argument_from_call_expr(call_expr->args, 0);
  73         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  74         new_state = filter_range(pre_state, whole_range.min, -4096);
  75         new_state = filter_range(new_state, 0, whole_range.max);
  76         set_extra_expr_nomod(arg, new_state);
  77 }
  78
  79 static void match_container_of(const char *fn, struct expression *expr, void *unused)
  80 {
  81         set_extra_expr_mod(expr->left, alloc_estate_range(valid_ptr_min, valid_ptr_max));
  82 }
  83
  84 void check_kernel(int id)
  85 {
  86         if (option_project != PROJ_KERNEL)
  87                 return;
  88
  89         add_implied_return_hook("ERR_PTR", &implied_err_cast_return, NULL);
  90         add_implied_return_hook("ERR_CAST", &implied_err_cast_return, NULL);
  91         add_implied_return_hook("PTR_ERR", &implied_err_cast_return, NULL);
  92         return_implies_state("IS_ERR_OR_NULL", 0, 0, &match_param_nonnull, (void *)0);
  93         return_implies_state("IS_ERR", 0, 0, &match_not_err, NULL);
  94         return_implies_state("IS_ERR", 1, 1, &match_err, NULL);
  95         return_implies_state("tomoyo_memory_ok", 1, 1, &match_param_nonnull, (void *)0);
  96         add_macro_assign_hook_extra("container_of", &match_container_of, NULL);
  97
  98         add_implied_return_hook("copy_to_user", &implied_copy_return, NULL);
  99         add_implied_return_hook("__copy_to_user", &implied_copy_return, NULL);
 100         add_implied_return_hook("copy_from_user", &implied_copy_return, NULL);
 101         add_implied_return_hook("__copy_fom_user", &implied_copy_return, NULL);
 102         add_implied_return_hook("clear_user", &implied_copy_return, NULL);
 103 }