libsanitizer/sanitizer_common/sanitizer_libignore.h

   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);
  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
  63   inline bool IsInRange(uptr pc, const LibCodeRange &range) const {
  64     return (pc >= range.begin && pc < range.end);
  65   }
  66
  67   static const uptr kMaxLibs = 128;
  68
  69   // Hot part:
  70   atomic_uintptr_t ignored_ranges_count_;
  71   LibCodeRange ignored_code_ranges_[kMaxLibs];
  72
  73   atomic_uintptr_t instrumented_ranges_count_;
  74   LibCodeRange instrumented_code_ranges_[kMaxLibs];
  75
  76   // Cold part:
  77   BlockingMutex mutex_;
  78   uptr count_;
  79   Lib libs_[kMaxLibs];
  80   bool track_instrumented_libs_;
  81
  82   // Disallow copying of LibIgnore objects.
  83   LibIgnore(const LibIgnore&);  // not implemented
  84   void operator = (const LibIgnore&);  // not implemented
  85 };
  86
  87 inline bool LibIgnore::IsIgnored(uptr pc, bool *pc_in_ignored_lib) const {
  88   const uptr n = atomic_load(&ignored_ranges_count_, memory_order_acquire);
  89   for (uptr i = 0; i < n; i++) {
  90     if (IsInRange(pc, ignored_code_ranges_[i])) {
  91       *pc_in_ignored_lib = true;
  92       return true;
  93     }
  94   }
  95   *pc_in_ignored_lib = false;
  96   if (track_instrumented_libs_ && !IsPcInstrumented(pc))
  97     return true;
  98   return false;
  99 }
 100
 101 inline bool LibIgnore::IsPcInstrumented(uptr pc) const {
 102   const uptr n = atomic_load(&instrumented_ranges_count_, memory_order_acquire);
 103   for (uptr i = 0; i < n; i++) {
 104     if (IsInRange(pc, instrumented_code_ranges_[i]))
 105       return true;
 106   }
 107   return false;
 108 }
 109
 110 }  // namespace __sanitizer
 111
 112 #endif  // SANITIZER_LIBIGNORE_H