1 //===-- sanitizer_symbolizer.h ----------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Symbolizer is used by sanitizers to map instruction address to a location in
11 // source code at run-time. Symbolizer either uses __sanitizer_symbolize_*
12 // defined in the program, or (if they are missing) tries to find and
13 // launch "llvm-symbolizer" commandline tool in a separate process and
14 // communicate with it.
16 // Generally we should try to avoid calling system library functions during
17 // symbolization (and use their replacements from sanitizer_libc.h instead).
18 //===----------------------------------------------------------------------===//
19 #ifndef SANITIZER_SYMBOLIZER_H
20 #define SANITIZER_SYMBOLIZER_H
22 #include "sanitizer_common.h"
23 #include "sanitizer_mutex.h"
25 namespace __sanitizer {
28 // Owns all the string members. Storage for them is
29 // (de)allocated using sanitizer internal allocator.
34 ModuleArch module_arch;
36 static const uptr kUnknown = ~(uptr)0;
45 // Deletes all strings and resets all fields.
47 void FillModuleInfo(const char *mod_name, uptr mod_offset, ModuleArch arch);
50 // Linked list of symbolized frames (each frame is described by AddressInfo).
51 struct SymbolizedStack {
52 SymbolizedStack *next;
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.
63 // For now, DataInfo is used to describe global variable.
65 // Owns all the string members. Storage for them is
66 // (de)allocated using sanitizer internal allocator.
69 ModuleArch module_arch;
83 class Symbolizer final {
85 /// Initialize and return platform-specific implementation of symbolizer
86 /// (if it wasn't already initialized).
87 static Symbolizer *GetOrInit();
88 static void LateInitialize();
89 // Returns a list of symbolized frames for a given address (containing
90 // all inlined functions, if necessary).
91 SymbolizedStack *SymbolizePC(uptr address);
92 bool SymbolizeData(uptr address, DataInfo *info);
94 // The module names Symbolizer returns are stable and unique for every given
95 // module. It is safe to store and compare them as pointers.
96 bool GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
97 uptr *module_address);
98 const char *GetModuleNameForPc(uptr pc) {
99 const char *module_name = nullptr;
101 if (GetModuleNameAndOffsetForPC(pc, &module_name, &unused))
106 // Release internal caches (if any).
108 // Attempts to demangle the provided C++ mangled name.
109 const char *Demangle(const char *name);
110 void PrepareForSandboxing();
112 // Allow user to install hooks that would be called before/after Symbolizer
113 // does the actual file/line info fetching. Specific sanitizers may need this
114 // to distinguish system library calls made in user code from calls made
115 // during in-process symbolization.
116 typedef void (*StartSymbolizationHook)();
117 typedef void (*EndSymbolizationHook)();
118 // May be called at most once.
119 void AddHooks(StartSymbolizationHook start_hook,
120 EndSymbolizationHook end_hook);
122 void RefreshModules();
123 const LoadedModule *FindModuleForAddress(uptr address);
125 void InvalidateModuleList();
128 // GetModuleNameAndOffsetForPC has to return a string to the caller.
129 // Since the corresponding module might get unloaded later, we should create
130 // our owned copies of the strings that we can safely return.
131 // ModuleNameOwner does not provide any synchronization, thus calls to
132 // its method should be protected by |mu_|.
133 class ModuleNameOwner {
135 explicit ModuleNameOwner(BlockingMutex *synchronized_by)
136 : storage_(kInitialCapacity), last_match_(nullptr),
137 mu_(synchronized_by) {}
138 const char *GetOwnedCopy(const char *str);
141 static const uptr kInitialCapacity = 1000;
142 InternalMmapVector<const char*> storage_;
143 const char *last_match_;
148 /// Platform-specific function for creating a Symbolizer object.
149 static Symbolizer *PlatformInit();
151 bool FindModuleNameAndOffsetForAddress(uptr address, const char **module_name,
153 ModuleArch *module_arch);
154 ListOfModules modules_;
155 ListOfModules fallback_modules_;
156 // If stale, need to reload the modules before looking up addresses.
159 // Platform-specific default demangler, must not return nullptr.
160 const char *PlatformDemangle(const char *name);
161 void PlatformPrepareForSandboxing();
163 static Symbolizer *symbolizer_;
164 static StaticSpinMutex init_mu_;
166 // Mutex locked from public methods of |Symbolizer|, so that the internals
167 // (including individual symbolizer tools and platform-specific methods) are
168 // always synchronized.
171 IntrusiveList<SymbolizerTool> tools_;
173 explicit Symbolizer(IntrusiveList<SymbolizerTool> tools);
175 static LowLevelAllocator symbolizer_allocator_;
177 StartSymbolizationHook start_hook_;
178 EndSymbolizationHook end_hook_;
179 class SymbolizerScope {
181 explicit SymbolizerScope(const Symbolizer *sym);
184 const Symbolizer *sym_;
188 #ifdef SANITIZER_WINDOWS
189 void InitializeDbgHelpIfNeeded();
192 } // namespace __sanitizer
194 #endif // SANITIZER_SYMBOLIZER_H