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   u8 uuid[kModuleUUIDSize];
  36   uptr uuid_size;
  37
  38   static const uptr kUnknown = ~(uptr)0;
  39   char *function;
  40   uptr function_offset;
  41
  42   char *file;
  43   int line;
  44   int column;
  45
  46   AddressInfo();
  47   // Deletes all strings and resets all fields.
  48   void Clear();
  49   void FillModuleInfo(const char *mod_name, uptr mod_offset, ModuleArch arch);
  50   void FillModuleInfo(const LoadedModule &mod);
  51   uptr module_base() const { return address - module_offset; }
  52 };
  53
  54 // Linked list of symbolized frames (each frame is described by AddressInfo).
  55 struct SymbolizedStack {
  56   SymbolizedStack *next;
  57   AddressInfo info;
  58   static SymbolizedStack *New(uptr addr);
  59   // Deletes current, and all subsequent frames in the linked list.
  60   // The object cannot be accessed after the call to this function.
  61   void ClearAll();
  62
  63  private:
  64   SymbolizedStack();
  65 };
  66
  67 // For now, DataInfo is used to describe global variable.
  68 struct DataInfo {
  69   // Owns all the string members. Storage for them is
  70   // (de)allocated using sanitizer internal allocator.
  71   char *module;
  72   uptr module_offset;
  73   ModuleArch module_arch;
  74
  75   char *file;
  76   uptr line;
  77   char *name;
  78   uptr start;
  79   uptr size;
  80
  81   DataInfo();
  82   void Clear();
  83 };
  84
  85 struct LocalInfo {
  86   char *function_name = nullptr;
  87   char *name = nullptr;
  88   char *decl_file = nullptr;
  89   unsigned decl_line = 0;
  90
  91   bool has_frame_offset = false;
  92   bool has_size = false;
  93   bool has_tag_offset = false;
  94
  95   sptr frame_offset;
  96   uptr size;
  97   uptr tag_offset;
  98
  99   void Clear();
 100 };
 101
 102 struct FrameInfo {
 103   char *module;
 104   uptr module_offset;
 105   ModuleArch module_arch;
 106
 107   InternalMmapVector<LocalInfo> locals;
 108   void Clear();
 109 };
 110
 111 class SymbolizerTool;
 112
 113 class Symbolizer final {
 114  public:
 115   /// Initialize and return platform-specific implementation of symbolizer
 116   /// (if it wasn't already initialized).
 117   static Symbolizer *GetOrInit();
 118   static void LateInitialize();
 119   // Returns a list of symbolized frames for a given address (containing
 120   // all inlined functions, if necessary).
 121   SymbolizedStack *SymbolizePC(uptr address);
 122   bool SymbolizeData(uptr address, DataInfo *info);
 123   bool SymbolizeFrame(uptr address, FrameInfo *info);
 124
 125   // The module names Symbolizer returns are stable and unique for every given
 126   // module.  It is safe to store and compare them as pointers.
 127   bool GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
 128                                    uptr *module_address);
 129   const char *GetModuleNameForPc(uptr pc) {
 130     const char *module_name = nullptr;
 131     uptr unused;
 132     if (GetModuleNameAndOffsetForPC(pc, &module_name, &unused))
 133       return module_name;
 134     return nullptr;
 135   }
 136
 137   // Release internal caches (if any).
 138   void Flush();
 139   // Attempts to demangle the provided C++ mangled name. Never returns nullptr.
 140   const char *Demangle(const char *name);
 141
 142   // Allow user to install hooks that would be called before/after Symbolizer
 143   // does the actual file/line info fetching. Specific sanitizers may need this
 144   // to distinguish system library calls made in user code from calls made
 145   // during in-process symbolization.
 146   typedef void (*StartSymbolizationHook)();
 147   typedef void (*EndSymbolizationHook)();
 148   // May be called at most once.
 149   void AddHooks(StartSymbolizationHook start_hook,
 150                 EndSymbolizationHook end_hook);
 151
 152   void RefreshModules();
 153   const LoadedModule *FindModuleForAddress(uptr address);
 154
 155   void InvalidateModuleList();
 156
 157  private:
 158   // GetModuleNameAndOffsetForPC has to return a string to the caller.
 159   // Since the corresponding module might get unloaded later, we should create
 160   // our owned copies of the strings that we can safely return.
 161   // ModuleNameOwner does not provide any synchronization, thus calls to
 162   // its method should be protected by |mu_|.
 163   class ModuleNameOwner {
 164    public:
 165     explicit ModuleNameOwner(Mutex *synchronized_by)
 166         : last_match_(nullptr), mu_(synchronized_by) {
 167       storage_.reserve(kInitialCapacity);
 168     }
 169     const char *GetOwnedCopy(const char *str);
 170
 171    private:
 172     static const uptr kInitialCapacity = 1000;
 173     InternalMmapVector<const char*> storage_;
 174     const char *last_match_;
 175
 176     Mutex *mu_;
 177   } module_names_;
 178
 179   /// Platform-specific function for creating a Symbolizer object.
 180   static Symbolizer *PlatformInit();
 181
 182   bool FindModuleNameAndOffsetForAddress(uptr address, const char **module_name,
 183                                          uptr *module_offset,
 184                                          ModuleArch *module_arch);
 185   ListOfModules modules_;
 186   ListOfModules fallback_modules_;
 187   // If stale, need to reload the modules before looking up addresses.
 188   bool modules_fresh_;
 189
 190   // Platform-specific default demangler, returns nullptr on failure.
 191   const char *PlatformDemangle(const char *name);
 192
 193   static Symbolizer *symbolizer_;
 194   static StaticSpinMutex init_mu_;
 195
 196   // Mutex locked from public methods of |Symbolizer|, so that the internals
 197   // (including individual symbolizer tools and platform-specific methods) are
 198   // always synchronized.
 199   Mutex mu_;
 200
 201   IntrusiveList<SymbolizerTool> tools_;
 202
 203   explicit Symbolizer(IntrusiveList<SymbolizerTool> tools);
 204
 205   static LowLevelAllocator symbolizer_allocator_;
 206
 207   StartSymbolizationHook start_hook_;
 208   EndSymbolizationHook end_hook_;
 209   class SymbolizerScope {
 210    public:
 211     explicit SymbolizerScope(const Symbolizer *sym);
 212     ~SymbolizerScope();
 213    private:
 214     const Symbolizer *sym_;
 215     int errno_;  // Backup errno in case symbolizer change the value.
 216   };
 217 };
 218
 219 #ifdef SANITIZER_WINDOWS
 220 void InitializeDbgHelpIfNeeded();
 221 #endif
 222
 223 }  // namespace __sanitizer
 224
 225 #endif  // SANITIZER_SYMBOLIZER_H