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 {
      37    void Clear() {
      38      descr[0] = 0;
      39      score = 0;
      40    }
      41    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    }
      47    int GetScore() const { return score; }
      48    const char *GetDescription() const { return descr; }
      49    void Print() const {
      50      if (score && flags()->print_scariness)
      51        Printf("SCARINESS: %d (%s)\n", score, descr);
      52    }
      53    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 {
      66    ScarinessScore() {
      67      Clear();
      68    }
      69  };
      70  
      71  }  // namespace __asan
      72  
      73  #endif  // ASAN_SCARINESS_SCORE_H