lib/sanitizer_common/sanitizer_libignore.h

   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 remembers all "called_from_lib" suppressions
  12 // from the provided SuppressionContext; 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_suppressions.h"
  23 #include "sanitizer_atomic.h"
  24 #include "sanitizer_mutex.h"
  25
  26 namespace __sanitizer {
  27
  28 class LibIgnore {
  29  public:
  30   explicit LibIgnore(LinkerInitialized);
  31
  32   // Fetches all "called_from_lib" suppressions from the SuppressionContext.
  33   void Init(const SuppressionContext &supp);
  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.
  42   bool IsIgnored(uptr pc) const;
  43
  44  private:
  45   struct Lib {
  46     char *templ;
  47     char *name;
  48     char *real_name;  // target of symlink
  49     bool loaded;
  50   };
  51
  52   struct LibCodeRange {
  53     uptr begin;
  54     uptr end;
  55   };
  56
  57   static const uptr kMaxLibs = 128;
  58
  59   // Hot part:
  60   atomic_uintptr_t loaded_count_;
  61   LibCodeRange code_ranges_[kMaxLibs];
  62
  63   // Cold part:
  64   BlockingMutex mutex_;
  65   uptr count_;
  66   Lib libs_[kMaxLibs];
  67
  68   // Disallow copying of LibIgnore objects.
  69   LibIgnore(const LibIgnore&);  // not implemented
  70   void operator = (const LibIgnore&);  // not implemented
  71 };
  72
  73 inline bool LibIgnore::IsIgnored(uptr pc) const {
  74   const uptr n = atomic_load(&loaded_count_, memory_order_acquire);
  75   for (uptr i = 0; i < n; i++) {
  76     if (pc >= code_ranges_[i].begin && pc < code_ranges_[i].end)
  77       return true;
  78   }
  79   return false;
  80 }
  81
  82 }  // namespace __sanitizer
  83
  84 #endif  // SANITIZER_LIBIGNORE_H