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
34  // Must be called after a new dynamic library is loaded.
35  void OnLibraryLoaded(const char *name);
36
37  // Must be called after a dynamic library is unloaded.
38  void OnLibraryUnloaded();
39
40  // Checks whether the provided PC belongs to one of the ignored libraries.
41  bool IsIgnored(uptr pc) const;
42
43 private:
44  struct Lib {
45    char *templ;
46    char *name;
47    char *real_name;  // target of symlink
48    bool loaded;
49  };
50
51  struct LibCodeRange {
52    uptr begin;
53    uptr end;
54  };
55
56  static const uptr kMaxLibs = 128;
57
58  // Hot part:
59  atomic_uintptr_t loaded_count_;
60  LibCodeRange code_ranges_[kMaxLibs];
61
62  // Cold part:
63  BlockingMutex mutex_;
64  uptr count_;
65  Lib libs_[kMaxLibs];
66
67  // Disallow copying of LibIgnore objects.
68  LibIgnore(const LibIgnore&);  // not implemented
69  void operator = (const LibIgnore&);  // not implemented
70};
71
72inline bool LibIgnore::IsIgnored(uptr pc) const {
73  const uptr n = atomic_load(&loaded_count_, memory_order_acquire);
74  for (uptr i = 0; i < n; i++) {
75    if (pc >= code_ranges_[i].begin && pc < code_ranges_[i].end)
76      return true;
77  }
78  return false;
79}
80
81}  // namespace __sanitizer
82
83#endif  // SANITIZER_LIBIGNORE_H
84