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1 //===-- sanitizer_symbolizer_libbacktrace.cc ------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is shared between AddressSanitizer and ThreadSanitizer
11 // run-time libraries.
12 // Libbacktrace implementation of symbolizer parts.
13 //===----------------------------------------------------------------------===//
14 
15 #include "sanitizer_platform.h"
16 
17 #include "sanitizer_internal_defs.h"
18 #include "sanitizer_symbolizer.h"
19 #include "sanitizer_symbolizer_libbacktrace.h"
20 
21 #if SANITIZER_LIBBACKTRACE
22 # include "backtrace-supported.h"
23 # if SANITIZER_POSIX && BACKTRACE_SUPPORTED && !BACKTRACE_USES_MALLOC
24 #  include "backtrace.h"
25 #  if SANITIZER_CP_DEMANGLE
26 #   undef ARRAY_SIZE
27 #   include "demangle.h"
28 #  endif
29 # else
30 #  define SANITIZER_LIBBACKTRACE 0
31 # endif
32 #endif
33 
34 namespace __sanitizer {
35 
36 #if SANITIZER_LIBBACKTRACE
37 
38 namespace {
39 
40 # if SANITIZER_CP_DEMANGLE
41 struct CplusV3DemangleData {
42   char *buf;
43   uptr size, allocated;
44 };
45 
46 extern "C" {
CplusV3DemangleCallback(const char * s,size_t l,void * vdata)47 static void CplusV3DemangleCallback(const char *s, size_t l, void *vdata) {
48   CplusV3DemangleData *data = (CplusV3DemangleData *)vdata;
49   uptr needed = data->size + l + 1;
50   if (needed > data->allocated) {
51     data->allocated *= 2;
52     if (needed > data->allocated)
53       data->allocated = needed;
54     char *buf = (char *)InternalAlloc(data->allocated);
55     if (data->buf) {
56       internal_memcpy(buf, data->buf, data->size);
57       InternalFree(data->buf);
58     }
59     data->buf = buf;
60   }
61   internal_memcpy(data->buf + data->size, s, l);
62   data->buf[data->size + l] = '\0';
63   data->size += l;
64 }
65 }  // extern "C"
66 
CplusV3Demangle(const char * name)67 char *CplusV3Demangle(const char *name) {
68   CplusV3DemangleData data;
69   data.buf = 0;
70   data.size = 0;
71   data.allocated = 0;
72   if (cplus_demangle_v3_callback(name, DMGL_PARAMS | DMGL_ANSI,
73                                  CplusV3DemangleCallback, &data)) {
74     if (data.size + 64 > data.allocated)
75       return data.buf;
76     char *buf = internal_strdup(data.buf);
77     InternalFree(data.buf);
78     return buf;
79   }
80   if (data.buf)
81     InternalFree(data.buf);
82   return 0;
83 }
84 # endif  // SANITIZER_CP_DEMANGLE
85 
86 struct SymbolizeCodeData {
87   AddressInfo *frames;
88   uptr n_frames;
89   uptr max_frames;
90   const char *module_name;
91   uptr module_offset;
92 };
93 
94 extern "C" {
SymbolizeCodePCInfoCallback(void * vdata,uintptr_t addr,const char * filename,int lineno,const char * function)95 static int SymbolizeCodePCInfoCallback(void *vdata, uintptr_t addr,
96                                        const char *filename, int lineno,
97                                        const char *function) {
98   SymbolizeCodeData *cdata = (SymbolizeCodeData *)vdata;
99   if (function) {
100     AddressInfo *info = &cdata->frames[cdata->n_frames++];
101     info->Clear();
102     info->FillAddressAndModuleInfo(addr, cdata->module_name,
103                                    cdata->module_offset);
104     info->function = LibbacktraceSymbolizer::Demangle(function, true);
105     if (filename)
106       info->file = internal_strdup(filename);
107     info->line = lineno;
108     if (cdata->n_frames == cdata->max_frames)
109       return 1;
110   }
111   return 0;
112 }
113 
SymbolizeCodeCallback(void * vdata,uintptr_t addr,const char * symname,uintptr_t,uintptr_t)114 static void SymbolizeCodeCallback(void *vdata, uintptr_t addr,
115                                   const char *symname, uintptr_t, uintptr_t) {
116   SymbolizeCodeData *cdata = (SymbolizeCodeData *)vdata;
117   if (symname) {
118     AddressInfo *info = &cdata->frames[0];
119     info->Clear();
120     info->FillAddressAndModuleInfo(addr, cdata->module_name,
121                                    cdata->module_offset);
122     info->function = LibbacktraceSymbolizer::Demangle(symname, true);
123     cdata->n_frames = 1;
124   }
125 }
126 
SymbolizeDataCallback(void * vdata,uintptr_t,const char * symname,uintptr_t symval,uintptr_t symsize)127 static void SymbolizeDataCallback(void *vdata, uintptr_t, const char *symname,
128                                   uintptr_t symval, uintptr_t symsize) {
129   DataInfo *info = (DataInfo *)vdata;
130   if (symname && symval) {
131     info->name = LibbacktraceSymbolizer::Demangle(symname, true);
132     info->start = symval;
133     info->size = symsize;
134   }
135 }
136 
ErrorCallback(void *,const char *,int)137 static void ErrorCallback(void *, const char *, int) {}
138 }  // extern "C"
139 
140 }  // namespace
141 
get(LowLevelAllocator * alloc)142 LibbacktraceSymbolizer *LibbacktraceSymbolizer::get(LowLevelAllocator *alloc) {
143   // State created in backtrace_create_state is leaked.
144   void *state = (void *)(backtrace_create_state("/proc/self/exe", 0,
145                                                 ErrorCallback, NULL));
146   if (!state)
147     return 0;
148   return new(*alloc) LibbacktraceSymbolizer(state);
149 }
150 
SymbolizeCode(uptr addr,AddressInfo * frames,uptr max_frames,const char * module_name,uptr module_offset)151 uptr LibbacktraceSymbolizer::SymbolizeCode(uptr addr, AddressInfo *frames,
152                                            uptr max_frames,
153                                            const char *module_name,
154                                            uptr module_offset) {
155   SymbolizeCodeData data;
156   data.frames = frames;
157   data.n_frames = 0;
158   data.max_frames = max_frames;
159   data.module_name = module_name;
160   data.module_offset = module_offset;
161   backtrace_pcinfo((backtrace_state *)state_, addr, SymbolizeCodePCInfoCallback,
162                    ErrorCallback, &data);
163   if (data.n_frames)
164     return data.n_frames;
165   backtrace_syminfo((backtrace_state *)state_, addr, SymbolizeCodeCallback,
166                     ErrorCallback, &data);
167   return data.n_frames;
168 }
169 
SymbolizeData(DataInfo * info)170 bool LibbacktraceSymbolizer::SymbolizeData(DataInfo *info) {
171   backtrace_syminfo((backtrace_state *)state_, info->address,
172                     SymbolizeDataCallback, ErrorCallback, info);
173   return true;
174 }
175 
176 #else  // SANITIZER_LIBBACKTRACE
177 
178 LibbacktraceSymbolizer *LibbacktraceSymbolizer::get(LowLevelAllocator *alloc) {
179   return 0;
180 }
181 
182 uptr LibbacktraceSymbolizer::SymbolizeCode(uptr addr, AddressInfo *frames,
183                                            uptr max_frames,
184                                            const char *module_name,
185                                            uptr module_offset) {
186   (void)state_;
187   return 0;
188 }
189 
190 bool LibbacktraceSymbolizer::SymbolizeData(DataInfo *info) {
191   return false;
192 }
193 
194 #endif  // SANITIZER_LIBBACKTRACE
195 
Demangle(const char * name,bool always_alloc)196 char *LibbacktraceSymbolizer::Demangle(const char *name, bool always_alloc) {
197 #if SANITIZER_LIBBACKTRACE && SANITIZER_CP_DEMANGLE
198   if (char *demangled = CplusV3Demangle(name))
199     return demangled;
200 #endif
201   if (always_alloc)
202     return internal_strdup(name);
203   return 0;
204 }
205 
206 }  // namespace __sanitizer
207