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 **rl)
  18 {
  19         struct expression *arg;
  20
  21         arg = get_argument_from_call_expr(call->args, 0);
  22         if (!get_implied_range_list(arg, rl))
  23                 *rl = alloc_range_list(-4095, -1);
  24         return 1;
  25 }
  26
  27 static int implied_copy_return(struct expression *call, void *unused, struct range_list **rl)
  28 {
  29         struct expression *arg;
  30         long long max;
  31
  32         arg = get_argument_from_call_expr(call->args, 2);
  33         if (!get_absolute_max(arg, &max))
  34                 max = whole_range.max;
  35         *rl = alloc_range_list(0, max);
  36         return 1;
  37 }
  38
  39 static void match_param_nonnull(const char *fn, struct expression *call_expr,
  40                         struct expression *assign_expr, void *_param)
  41 {
  42         int param = PTR_INT(_param);
  43         struct expression *arg;
  44         struct smatch_state *pre_state;
  45         struct smatch_state *true_state;
  46
  47         arg = get_argument_from_call_expr(call_expr->args, param);
  48         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  49         true_state = add_filter(pre_state, 0);
  50         set_extra_expr_nomod(arg, true_state);
  51 }
  52
  53 static void match_not_err(const char *fn, struct expression *call_expr,
  54                         struct expression *assign_expr, void *unused)
  55 {
  56         struct expression *arg;
  57         struct smatch_state *pre_state;
  58         struct smatch_state *new_state;
  59
  60         arg = get_argument_from_call_expr(call_expr->args, 0);
  61         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  62         new_state = filter_range(pre_state, whole_range.min, -1);
  63         set_extra_expr_nomod(arg, new_state);
  64 }
  65
  66 static void match_err(const char *fn, struct expression *call_expr,
  67                         struct expression *assign_expr, void *unused)
  68 {
  69         struct expression *arg;
  70         struct smatch_state *pre_state;
  71         struct smatch_state *new_state;
  72
  73         arg = get_argument_from_call_expr(call_expr->args, 0);
  74         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  75         new_state = filter_range(pre_state, whole_range.min, -4096);
  76         new_state = filter_range(new_state, 0, whole_range.max);
  77         set_extra_expr_nomod(arg, new_state);
  78 }
  79
  80 static void match_container_of(const char *fn, struct expression *expr, void *unused)
  81 {
  82         set_extra_expr_mod(expr->left, alloc_estate_range(valid_ptr_min, valid_ptr_max));
  83 }
  84
  85 void check_kernel(int id)
  86 {
  87         if (option_project != PROJ_KERNEL)
  88                 return;
  89
  90         add_implied_return_hook("ERR_PTR", &implied_err_cast_return, NULL);
  91         add_implied_return_hook("ERR_CAST", &implied_err_cast_return, NULL);
  92         add_implied_return_hook("PTR_ERR", &implied_err_cast_return, NULL);
  93         return_implies_state("IS_ERR_OR_NULL", 0, 0, &match_param_nonnull, (void *)0);
  94         return_implies_state("IS_ERR", 0, 0, &match_not_err, NULL);
  95         return_implies_state("IS_ERR", 1, 1, &match_err, NULL);
  96         return_implies_state("tomoyo_memory_ok", 1, 1, &match_param_nonnull, (void *)0);
  97         add_macro_assign_hook_extra("container_of", &match_container_of, NULL);
  98
  99         add_implied_return_hook("copy_to_user", &implied_copy_return, NULL);
 100         add_implied_return_hook("__copy_to_user", &implied_copy_return, NULL);
 101         add_implied_return_hook("copy_from_user", &implied_copy_return, NULL);
 102         add_implied_return_hook("__copy_fom_user", &implied_copy_return, NULL);
 103         add_implied_return_hook("clear_user", &implied_copy_return, NULL);
 104 }