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