1 //===-- asan_scariness_score.h ----------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // Compute the level of scariness of the error message.
12 // Don't expect any deep science here, just a set of heuristics that suggest
13 // that e.g. 1-byte-read-global-buffer-overflow is less scary than
14 // 8-byte-write-stack-use-after-return.
15 //
16 // Every error report has one or more features, such as memory access size,
17 // type (read or write), type of accessed memory (e.g. free-d heap, or a global
18 // redzone), etc. Every such feature has an int score and a string description.
19 // The overall score is the sum of all feature scores and the description
20 // is a concatenation of feature descriptions.
21 // Examples:
22 //  17 (4-byte-read-heap-buffer-overflow)
23 //  65 (multi-byte-write-stack-use-after-return)
24 //  10 (null-deref)
25 //
26 //===----------------------------------------------------------------------===//
27 
28 #ifndef ASAN_SCARINESS_SCORE_H
29 #define ASAN_SCARINESS_SCORE_H
30 
31 #include "asan_flags.h"
32 #include "sanitizer_common/sanitizer_common.h"
33 #include "sanitizer_common/sanitizer_libc.h"
34 
35 namespace __asan {
36 struct ScarinessScoreBase {
ClearScarinessScoreBase37   void Clear() {
38     descr[0] = 0;
39     score = 0;
40   }
ScareScarinessScoreBase41   void Scare(int add_to_score, const char *reason) {
42     if (descr[0])
43       internal_strlcat(descr, "-", sizeof(descr));
44     internal_strlcat(descr, reason, sizeof(descr));
45     score += add_to_score;
46   }
GetScoreScarinessScoreBase47   int GetScore() const { return score; }
GetDescriptionScarinessScoreBase48   const char *GetDescription() const { return descr; }
PrintScarinessScoreBase49   void Print() const {
50     if (score && flags()->print_scariness)
51       Printf("SCARINESS: %d (%s)\n", score, descr);
52   }
PrintSimpleScarinessScoreBase53   static void PrintSimple(int score, const char *descr) {
54     ScarinessScoreBase SSB;
55     SSB.Clear();
56     SSB.Scare(score, descr);
57     SSB.Print();
58   }
59 
60  private:
61   int score;
62   char descr[1024];
63 };
64 
65 struct ScarinessScore : ScarinessScoreBase {
ScarinessScoreScarinessScore66   ScarinessScore() {
67     Clear();
68   }
69 };
70 
71 }  // namespace __asan
72 
73 #endif  // ASAN_SCARINESS_SCORE_H
74