1 //===-- sanitizer_symbolize.cpp ---------------------------------*- 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 // Implementation of weak hooks from sanitizer_symbolizer_posix_libcdep.cpp.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include <inttypes.h>
14 #include <stdio.h>
15 
16 #include <string>
17 
18 #include "llvm/DebugInfo/Symbolize/DIPrinter.h"
19 #include "llvm/DebugInfo/Symbolize/Symbolize.h"
20 #include "llvm/Demangle/Demangle.h"
21 
22 static llvm::symbolize::LLVMSymbolizer *Symbolizer = nullptr;
23 static bool Demangle = true;
24 static bool InlineFrames = true;
25 
getDefaultSymbolizer()26 static llvm::symbolize::LLVMSymbolizer *getDefaultSymbolizer() {
27   if (Symbolizer)
28     return Symbolizer;
29   llvm::symbolize::LLVMSymbolizer::Options Opts;
30   Opts.Demangle = Demangle;
31   Opts.UntagAddresses = true;
32   Symbolizer = new llvm::symbolize::LLVMSymbolizer(Opts);
33   return Symbolizer;
34 }
35 
getDefaultPrinterConfig()36 static llvm::symbolize::PrinterConfig getDefaultPrinterConfig() {
37   llvm::symbolize::PrinterConfig Config;
38   Config.Pretty = false;
39   Config.Verbose = false;
40   Config.PrintFunctions = true;
41   Config.PrintAddress = false;
42   Config.SourceContextLines = 0;
43   return Config;
44 }
45 
symbolize_error_handler(llvm::raw_string_ostream & OS)46 static llvm::symbolize::ErrorHandler symbolize_error_handler(
47     llvm::raw_string_ostream &OS) {
48   return
49       [&](const llvm::ErrorInfoBase &ErrorInfo, llvm::StringRef ErrorBanner) {
50         OS << ErrorBanner;
51         ErrorInfo.log(OS);
52         OS << '\n';
53       };
54 }
55 
56 namespace __sanitizer {
57 int internal_snprintf(char *buffer, uintptr_t length, const char *format, ...);
58 }  // namespace __sanitizer
59 
60 extern "C" {
61 
62 typedef uint64_t u64;
63 
__sanitizer_symbolize_code(const char * ModuleName,uint64_t ModuleOffset,char * Buffer,int MaxLength)64 bool __sanitizer_symbolize_code(const char *ModuleName, uint64_t ModuleOffset,
65                                 char *Buffer, int MaxLength) {
66   std::string Result;
67   {
68     llvm::raw_string_ostream OS(Result);
69     llvm::symbolize::PrinterConfig Config = getDefaultPrinterConfig();
70     llvm::symbolize::Request Request{ModuleName, ModuleOffset};
71     auto Printer = std::make_unique<llvm::symbolize::LLVMPrinter>(
72         OS, symbolize_error_handler(OS), Config);
73 
74     // TODO: it is necessary to set proper SectionIndex here.
75     // object::SectionedAddress::UndefSection works for only absolute addresses.
76     if (InlineFrames) {
77       auto ResOrErr = getDefaultSymbolizer()->symbolizeInlinedCode(
78           ModuleName,
79           {ModuleOffset, llvm::object::SectionedAddress::UndefSection});
80       if (!ResOrErr)
81         return false;
82       Printer->print(Request, ResOrErr.get());
83     } else {
84       auto ResOrErr = getDefaultSymbolizer()->symbolizeCode(
85           ModuleName,
86           {ModuleOffset, llvm::object::SectionedAddress::UndefSection});
87       if (!ResOrErr)
88         return false;
89       Printer->print(Request, ResOrErr.get());
90     }
91   }
92   return __sanitizer::internal_snprintf(Buffer, MaxLength, "%s",
93                                         Result.c_str()) < MaxLength;
94 }
95 
__sanitizer_symbolize_data(const char * ModuleName,uint64_t ModuleOffset,char * Buffer,int MaxLength)96 bool __sanitizer_symbolize_data(const char *ModuleName, uint64_t ModuleOffset,
97                                 char *Buffer, int MaxLength) {
98   std::string Result;
99   {
100     llvm::symbolize::PrinterConfig Config = getDefaultPrinterConfig();
101     llvm::raw_string_ostream OS(Result);
102     llvm::symbolize::Request Request{ModuleName, ModuleOffset};
103     auto Printer = std::make_unique<llvm::symbolize::LLVMPrinter>(
104         OS, symbolize_error_handler(OS), Config);
105 
106     // TODO: it is necessary to set proper SectionIndex here.
107     // object::SectionedAddress::UndefSection works for only absolute addresses.
108     auto ResOrErr = getDefaultSymbolizer()->symbolizeData(
109         ModuleName,
110         {ModuleOffset, llvm::object::SectionedAddress::UndefSection});
111     if (!ResOrErr)
112       return false;
113     Printer->print(Request, ResOrErr.get());
114   }
115   return __sanitizer::internal_snprintf(Buffer, MaxLength, "%s",
116                                         Result.c_str()) < MaxLength;
117 }
118 
__sanitizer_symbolize_frame(const char * ModuleName,uint64_t ModuleOffset,char * Buffer,int MaxLength)119 bool __sanitizer_symbolize_frame(const char *ModuleName, uint64_t ModuleOffset,
120                                  char *Buffer, int MaxLength) {
121   std::string Result;
122   {
123     llvm::symbolize::PrinterConfig Config = getDefaultPrinterConfig();
124     llvm::raw_string_ostream OS(Result);
125     llvm::symbolize::Request Request{ModuleName, ModuleOffset};
126     auto Printer = std::make_unique<llvm::symbolize::LLVMPrinter>(
127         OS, symbolize_error_handler(OS), Config);
128 
129     // TODO: it is necessary to set proper SectionIndex here.
130     // object::SectionedAddress::UndefSection works for only absolute addresses.
131     auto ResOrErr = getDefaultSymbolizer()->symbolizeFrame(
132         ModuleName,
133         {ModuleOffset, llvm::object::SectionedAddress::UndefSection});
134     if (!ResOrErr)
135       return false;
136     Printer->print(Request, ResOrErr.get());
137   }
138   return __sanitizer::internal_snprintf(Buffer, MaxLength, "%s",
139                                         Result.c_str()) < MaxLength;
140 }
141 
__sanitizer_symbolize_flush()142 void __sanitizer_symbolize_flush() {
143   if (Symbolizer)
144     Symbolizer->flush();
145 }
146 
__sanitizer_symbolize_demangle(const char * Name,char * Buffer,int MaxLength)147 bool __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
148                                     int MaxLength) {
149   std::string Result;
150   if (!llvm::nonMicrosoftDemangle(Name, Result))
151     return false;
152   return __sanitizer::internal_snprintf(Buffer, MaxLength, "%s",
153                                         Result.c_str()) < MaxLength;
154 }
155 
__sanitizer_symbolize_set_demangle(bool Value)156 bool __sanitizer_symbolize_set_demangle(bool Value) {
157   // Must be called before LLVMSymbolizer created.
158   if (Symbolizer)
159     return false;
160   Demangle = Value;
161   return true;
162 }
163 
__sanitizer_symbolize_set_inline_frames(bool Value)164 bool __sanitizer_symbolize_set_inline_frames(bool Value) {
165   InlineFrames = Value;
166   return true;
167 }
168 
169 // Override __cxa_atexit and ignore callbacks.
170 // This prevents crashes in a configuration when the symbolizer
171 // is built into sanitizer runtime and consequently into the test process.
172 // LLVM libraries have some global objects destroyed during exit,
173 // so if the test process triggers any bugs after that, the symbolizer crashes.
174 // An example stack trace of such crash:
175 //
176 // #1  __cxa_throw
177 // #2  std::__u::__throw_system_error
178 // #3  std::__u::recursive_mutex::lock
179 // #4  __sanitizer_llvm::ManagedStaticBase::RegisterManagedStatic
180 // #5  __sanitizer_llvm::errorToErrorCode
181 // #6  __sanitizer_llvm::getFileAux
182 // #7  __sanitizer_llvm::MemoryBuffer::getFileOrSTDIN
183 // #10 __sanitizer_llvm::symbolize::LLVMSymbolizer::getOrCreateModuleInfo
184 // #13 __sanitizer::Symbolizer::SymbolizeData
185 // #14 __tsan::SymbolizeData
186 // #16 __tsan::ReportRace
187 // #18 __tsan_write4
188 // #19 race() () at test/tsan/atexit4.cpp
189 // #20 cxa_at_exit_wrapper
190 // #21 __cxa_finalize
191 // #22 __do_fini
192 //
193 // For the standalone llvm-symbolizer this does not hurt,
194 // we just don't destroy few global objects on exit.
__cxa_atexit(void (* f)(void * a),void * arg,void * dso)195 int __cxa_atexit(void (*f)(void *a), void *arg, void *dso) { return 0; }
196 
197 }  // extern "C"
198