libsanitizer/sanitizer_common/sanitizer_symbolizer.h

   1 //===-- sanitizer_symbolizer.h ----------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Symbolizer is used by sanitizers to map instruction address to a location in
  10 // source code at run-time. Symbolizer either uses __sanitizer_symbolize_*
  11 // defined in the program, or (if they are missing) tries to find and
  12 // launch "llvm-symbolizer" commandline tool in a separate process and
  13 // communicate with it.
  14 //
  15 // Generally we should try to avoid calling system library functions during
  16 // symbolization (and use their replacements from sanitizer_libc.h instead).
  17 //===----------------------------------------------------------------------===//
  18 #ifndef SANITIZER_SYMBOLIZER_H
  19 #define SANITIZER_SYMBOLIZER_H
  20
  21 #include "sanitizer_common.h"
  22 #include "sanitizer_mutex.h"
  23 #include "sanitizer_vector.h"
  24
  25 namespace __sanitizer {
  26
  27 struct AddressInfo {
  28   // Owns all the string members. Storage for them is
  29   // (de)allocated using sanitizer internal allocator.
  30   uptr address;
  31
  32   char *module;
  33   uptr module_offset;
  34   ModuleArch module_arch;
  35
  36   static const uptr kUnknown = ~(uptr)0;
  37   char *function;
  38   uptr function_offset;
  39
  40   char *file;
  41   int line;
  42   int column;
  43
  44   AddressInfo();
  45   // Deletes all strings and resets all fields.
  46   void Clear();
  47   void FillModuleInfo(const char *mod_name, uptr mod_offset, ModuleArch arch);
  48 };
  49
  50 // Linked list of symbolized frames (each frame is described by AddressInfo).
  51 struct SymbolizedStack {
  52   SymbolizedStack *next;
  53   AddressInfo info;
  54   static SymbolizedStack *New(uptr addr);
  55   // Deletes current, and all subsequent frames in the linked list.
  56   // The object cannot be accessed after the call to this function.
  57   void ClearAll();
  58
  59  private:
  60   SymbolizedStack();
  61 };
  62
  63 // For now, DataInfo is used to describe global variable.
  64 struct DataInfo {
  65   // Owns all the string members. Storage for them is
  66   // (de)allocated using sanitizer internal allocator.
  67   char *module;
  68   uptr module_offset;
  69   ModuleArch module_arch;
  70
  71   char *file;
  72   uptr line;
  73   char *name;
  74   uptr start;
  75   uptr size;
  76
  77   DataInfo();
  78   void Clear();
  79 };
  80
  81 struct LocalInfo {
  82   char *function_name = nullptr;
  83   char *name = nullptr;
  84   char *decl_file = nullptr;
  85   unsigned decl_line = 0;
  86
  87   bool has_frame_offset = false;
  88   bool has_size = false;
  89   bool has_tag_offset = false;
  90
  91   sptr frame_offset;
  92   uptr size;
  93   uptr tag_offset;
  94
  95   void Clear();
  96 };
  97
  98 struct FrameInfo {
  99   char *module;
 100   uptr module_offset;
 101   ModuleArch module_arch;
 102
 103   InternalMmapVector<LocalInfo> locals;
 104   void Clear();
 105 };
 106
 107 class SymbolizerTool;
 108
 109 class Symbolizer final {
 110  public:
 111   /// Initialize and return platform-specific implementation of symbolizer
 112   /// (if it wasn't already initialized).
 113   static Symbolizer *GetOrInit();
 114   static void LateInitialize();
 115   // Returns a list of symbolized frames for a given address (containing
 116   // all inlined functions, if necessary).
 117   SymbolizedStack *SymbolizePC(uptr address);
 118   bool SymbolizeData(uptr address, DataInfo *info);
 119   bool SymbolizeFrame(uptr address, FrameInfo *info);
 120
 121   // The module names Symbolizer returns are stable and unique for every given
 122   // module.  It is safe to store and compare them as pointers.
 123   bool GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
 124                                    uptr *module_address);
 125   const char *GetModuleNameForPc(uptr pc) {
 126     const char *module_name = nullptr;
 127     uptr unused;
 128     if (GetModuleNameAndOffsetForPC(pc, &module_name, &unused))
 129       return module_name;
 130     return nullptr;
 131   }
 132
 133   // Release internal caches (if any).
 134   void Flush();
 135   // Attempts to demangle the provided C++ mangled name.
 136   const char *Demangle(const char *name);
 137
 138   // Allow user to install hooks that would be called before/after Symbolizer
 139   // does the actual file/line info fetching. Specific sanitizers may need this
 140   // to distinguish system library calls made in user code from calls made
 141   // during in-process symbolization.
 142   typedef void (*StartSymbolizationHook)();
 143   typedef void (*EndSymbolizationHook)();
 144   // May be called at most once.
 145   void AddHooks(StartSymbolizationHook start_hook,
 146                 EndSymbolizationHook end_hook);
 147
 148   void RefreshModules();
 149   const LoadedModule *FindModuleForAddress(uptr address);
 150
 151   void InvalidateModuleList();
 152
 153  private:
 154   // GetModuleNameAndOffsetForPC has to return a string to the caller.
 155   // Since the corresponding module might get unloaded later, we should create
 156   // our owned copies of the strings that we can safely return.
 157   // ModuleNameOwner does not provide any synchronization, thus calls to
 158   // its method should be protected by |mu_|.
 159   class ModuleNameOwner {
 160    public:
 161     explicit ModuleNameOwner(BlockingMutex *synchronized_by)
 162         : last_match_(nullptr), mu_(synchronized_by) {
 163       storage_.reserve(kInitialCapacity);
 164     }
 165     const char *GetOwnedCopy(const char *str);
 166
 167    private:
 168     static const uptr kInitialCapacity = 1000;
 169     InternalMmapVector<const char*> storage_;
 170     const char *last_match_;
 171
 172     BlockingMutex *mu_;
 173   } module_names_;
 174
 175   /// Platform-specific function for creating a Symbolizer object.
 176   static Symbolizer *PlatformInit();
 177
 178   bool FindModuleNameAndOffsetForAddress(uptr address, const char **module_name,
 179                                          uptr *module_offset,
 180                                          ModuleArch *module_arch);
 181   ListOfModules modules_;
 182   ListOfModules fallback_modules_;
 183   // If stale, need to reload the modules before looking up addresses.
 184   bool modules_fresh_;
 185
 186   // Platform-specific default demangler, must not return nullptr.
 187   const char *PlatformDemangle(const char *name);
 188
 189   static Symbolizer *symbolizer_;
 190   static StaticSpinMutex init_mu_;
 191
 192   // Mutex locked from public methods of |Symbolizer|, so that the internals
 193   // (including individual symbolizer tools and platform-specific methods) are
 194   // always synchronized.
 195   BlockingMutex mu_;
 196
 197   IntrusiveList<SymbolizerTool> tools_;
 198
 199   explicit Symbolizer(IntrusiveList<SymbolizerTool> tools);
 200
 201   static LowLevelAllocator symbolizer_allocator_;
 202
 203   StartSymbolizationHook start_hook_;
 204   EndSymbolizationHook end_hook_;
 205   class SymbolizerScope {
 206    public:
 207     explicit SymbolizerScope(const Symbolizer *sym);
 208     ~SymbolizerScope();
 209    private:
 210     const Symbolizer *sym_;
 211   };
 212
 213   // Calls `LateInitialize()` on all items in `tools_`.
 214   void LateInitializeTools();
 215 };
 216
 217 #ifdef SANITIZER_WINDOWS
 218 void InitializeDbgHelpIfNeeded();
 219 #endif
 220
 221 }  // namespace __sanitizer
 222
 223 #endif  // SANITIZER_SYMBOLIZER_H