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 remembers all "called_from_lib" suppressions
  10 // from the provided SuppressionContext; 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_suppressions.h"
  21 #include "sanitizer_atomic.h"
  22 #include "sanitizer_mutex.h"
  23
  24 namespace __sanitizer {
  25
  26 class LibIgnore {
  27  public:
  28   explicit LibIgnore(LinkerInitialized);
  29
  30   // Fetches all "called_from_lib" suppressions from the SuppressionContext.
  31   void Init(const SuppressionContext &supp);
  32
  33   // Must be called after a new dynamic library is loaded.
  34   void OnLibraryLoaded(const char *name);
  35
  36   // Must be called after a dynamic library is unloaded.
  37   void OnLibraryUnloaded();
  38
  39   // Checks whether the provided PC belongs to one of the ignored libraries.
  40   bool IsIgnored(uptr pc) const;
  41
  42  private:
  43   struct Lib {
  44     char *templ;
  45     char *name;
  46     char *real_name;  // target of symlink
  47     bool loaded;
  48   };
  49
  50   struct LibCodeRange {
  51     uptr begin;
  52     uptr end;
  53   };
  54
  55   static const uptr kMaxLibs = 128;
  56
  57   // Hot part:
  58   atomic_uintptr_t loaded_count_;
  59   LibCodeRange code_ranges_[kMaxLibs];
  60
  61   // Cold part:
  62   BlockingMutex mutex_;
  63   uptr count_;
  64   Lib libs_[kMaxLibs];
  65
  66   // Disallow copying of LibIgnore objects.
  67   LibIgnore(const LibIgnore&);  // not implemented
  68   void operator = (const LibIgnore&);  // not implemented
  69 };
  70
  71 inline bool LibIgnore::IsIgnored(uptr pc) const {
  72   const uptr n = atomic_load(&loaded_count_, memory_order_acquire);
  73   for (uptr i = 0; i < n; i++) {
  74     if (pc >= code_ranges_[i].begin && pc < code_ranges_[i].end)
  75       return true;
  76   }
  77   return false;
  78 }
  79
  80 }  // namespace __sanitizer
  81
  82 #endif  // SANITIZER_LIBIGNORE_H