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