1//===-- sanitizer_libignore.h -----------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// LibIgnore allows to ignore all interceptors called from a particular set
11// of dynamic libraries. LibIgnore can be initialized with several templates
12// of names of libraries to be ignored. It finds code ranges for the libraries;
13// and checks whether the provided PC value belongs to the code ranges.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef SANITIZER_LIBIGNORE_H
18#define SANITIZER_LIBIGNORE_H
19
20#include "sanitizer_internal_defs.h"
21#include "sanitizer_common.h"
22#include "sanitizer_atomic.h"
23#include "sanitizer_mutex.h"
24
25namespace __sanitizer {
26
27class LibIgnore {
28 public:
29  explicit LibIgnore(LinkerInitialized);
30
31  // Must be called during initialization.
32  void AddIgnoredLibrary(const char *name_templ);
33  void IgnoreNoninstrumentedModules(bool enable) {
34    track_instrumented_libs_ = enable;
35  }
36
37  // Must be called after a new dynamic library is loaded.
38  void OnLibraryLoaded(const char *name);
39
40  // Must be called after a dynamic library is unloaded.
41  void OnLibraryUnloaded();
42
43  // Checks whether the provided PC belongs to one of the ignored libraries or
44  // the PC should be ignored because it belongs to an non-instrumented module
45  // (when ignore_noninstrumented_modules=1). Also returns true via
46  // "pc_in_ignored_lib" if the PC is in an ignored library, false otherwise.
47  bool IsIgnored(uptr pc, bool *pc_in_ignored_lib) const;
48
49  // Checks whether the provided PC belongs to an instrumented module.
50  bool IsPcInstrumented(uptr pc) const;
51
52 private:
53  struct Lib {
54    char *templ;
55    char *name;
56    char *real_name;  // target of symlink
57    bool loaded;
58  };
59
60  struct LibCodeRange {
61    uptr begin;
62    uptr end;
63  };
64
65  inline bool IsInRange(uptr pc, const LibCodeRange &range) const {
66    return (pc >= range.begin && pc < range.end);
67  }
68
69  static const uptr kMaxIgnoredRanges = 128;
70  static const uptr kMaxInstrumentedRanges = 1024;
71  static const uptr kMaxLibs = 1024;
72
73  // Hot part:
74  atomic_uintptr_t ignored_ranges_count_;
75  LibCodeRange ignored_code_ranges_[kMaxIgnoredRanges];
76
77  atomic_uintptr_t instrumented_ranges_count_;
78  LibCodeRange instrumented_code_ranges_[kMaxInstrumentedRanges];
79
80  // Cold part:
81  BlockingMutex mutex_;
82  uptr count_;
83  Lib libs_[kMaxLibs];
84  bool track_instrumented_libs_;
85
86  // Disallow copying of LibIgnore objects.
87  LibIgnore(const LibIgnore&);  // not implemented
88  void operator = (const LibIgnore&);  // not implemented
89};
90
91inline bool LibIgnore::IsIgnored(uptr pc, bool *pc_in_ignored_lib) const {
92  const uptr n = atomic_load(&ignored_ranges_count_, memory_order_acquire);
93  for (uptr i = 0; i < n; i++) {
94    if (IsInRange(pc, ignored_code_ranges_[i])) {
95      *pc_in_ignored_lib = true;
96      return true;
97    }
98  }
99  *pc_in_ignored_lib = false;
100  if (track_instrumented_libs_ && !IsPcInstrumented(pc))
101    return true;
102  return false;
103}
104
105inline bool LibIgnore::IsPcInstrumented(uptr pc) const {
106  const uptr n = atomic_load(&instrumented_ranges_count_, memory_order_acquire);
107  for (uptr i = 0; i < n; i++) {
108    if (IsInRange(pc, instrumented_code_ranges_[i]))
109      return true;
110  }
111  return false;
112}
113
114}  // namespace __sanitizer
115
116#endif  // SANITIZER_LIBIGNORE_H
117