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