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