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 static char *DemangleAlloc(const char *name, bool always_alloc);
37 
38 #if SANITIZER_LIBBACKTRACE
39 
40 namespace {
41 
42 # if SANITIZER_CP_DEMANGLE
43 struct CplusV3DemangleData {
44   char *buf;
45   uptr size, allocated;
46 };
47 
48 extern "C" {
CplusV3DemangleCallback(const char * s,size_t l,void * vdata)49 static void CplusV3DemangleCallback(const char *s, size_t l, void *vdata) {
50   CplusV3DemangleData *data = (CplusV3DemangleData *)vdata;
51   uptr needed = data->size + l + 1;
52   if (needed > data->allocated) {
53     data->allocated *= 2;
54     if (needed > data->allocated)
55       data->allocated = needed;
56     char *buf = (char *)InternalAlloc(data->allocated);
57     if (data->buf) {
58       internal_memcpy(buf, data->buf, data->size);
59       InternalFree(data->buf);
60     }
61     data->buf = buf;
62   }
63   internal_memcpy(data->buf + data->size, s, l);
64   data->buf[data->size + l] = '\0';
65   data->size += l;
66 }
67 }  // extern "C"
68 
CplusV3Demangle(const char * name)69 char *CplusV3Demangle(const char *name) {
70   CplusV3DemangleData data;
71   data.buf = 0;
72   data.size = 0;
73   data.allocated = 0;
74   if (cplus_demangle_v3_callback(name, DMGL_PARAMS | DMGL_ANSI,
75                                  CplusV3DemangleCallback, &data)) {
76     if (data.size + 64 > data.allocated)
77       return data.buf;
78     char *buf = internal_strdup(data.buf);
79     InternalFree(data.buf);
80     return buf;
81   }
82   if (data.buf)
83     InternalFree(data.buf);
84   return 0;
85 }
86 # endif  // SANITIZER_CP_DEMANGLE
87 
88 struct SymbolizeCodeCallbackArg {
89   SymbolizedStack *first;
90   SymbolizedStack *last;
91   uptr frames_symbolized;
92 
get_new_frame__sanitizer::__anon417358b60111::SymbolizeCodeCallbackArg93   AddressInfo *get_new_frame(uintptr_t addr) {
94     CHECK(last);
95     if (frames_symbolized > 0) {
96       SymbolizedStack *cur = SymbolizedStack::New(addr);
97       AddressInfo *info = &cur->info;
98       info->FillModuleInfo(first->info.module, first->info.module_offset);
99       last->next = cur;
100       last = cur;
101     }
102     CHECK_EQ(addr, first->info.address);
103     CHECK_EQ(addr, last->info.address);
104     return &last->info;
105   }
106 };
107 
108 extern "C" {
SymbolizeCodePCInfoCallback(void * vdata,uintptr_t addr,const char * filename,int lineno,const char * function)109 static int SymbolizeCodePCInfoCallback(void *vdata, uintptr_t addr,
110                                        const char *filename, int lineno,
111                                        const char *function) {
112   SymbolizeCodeCallbackArg *cdata = (SymbolizeCodeCallbackArg *)vdata;
113   if (function) {
114     AddressInfo *info = cdata->get_new_frame(addr);
115     info->function = DemangleAlloc(function, /*always_alloc*/ true);
116     if (filename)
117       info->file = internal_strdup(filename);
118     info->line = lineno;
119     cdata->frames_symbolized++;
120   }
121   return 0;
122 }
123 
SymbolizeCodeCallback(void * vdata,uintptr_t addr,const char * symname,uintptr_t,uintptr_t)124 static void SymbolizeCodeCallback(void *vdata, uintptr_t addr,
125                                   const char *symname, uintptr_t, uintptr_t) {
126   SymbolizeCodeCallbackArg *cdata = (SymbolizeCodeCallbackArg *)vdata;
127   if (symname) {
128     AddressInfo *info = cdata->get_new_frame(addr);
129     info->function = DemangleAlloc(symname, /*always_alloc*/ true);
130     cdata->frames_symbolized++;
131   }
132 }
133 
SymbolizeDataCallback(void * vdata,uintptr_t,const char * symname,uintptr_t symval,uintptr_t symsize)134 static void SymbolizeDataCallback(void *vdata, uintptr_t, const char *symname,
135                                   uintptr_t symval, uintptr_t symsize) {
136   DataInfo *info = (DataInfo *)vdata;
137   if (symname && symval) {
138     info->name = DemangleAlloc(symname, /*always_alloc*/ true);
139     info->start = symval;
140     info->size = symsize;
141   }
142 }
143 
ErrorCallback(void *,const char *,int)144 static void ErrorCallback(void *, const char *, int) {}
145 }  // extern "C"
146 
147 }  // namespace
148 
get(LowLevelAllocator * alloc)149 LibbacktraceSymbolizer *LibbacktraceSymbolizer::get(LowLevelAllocator *alloc) {
150   // State created in backtrace_create_state is leaked.
151   void *state = (void *)(backtrace_create_state("/proc/self/exe", 0,
152                                                 ErrorCallback, NULL));
153   if (!state)
154     return 0;
155   return new(*alloc) LibbacktraceSymbolizer(state);
156 }
157 
SymbolizePC(uptr addr,SymbolizedStack * stack)158 bool LibbacktraceSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
159   SymbolizeCodeCallbackArg data;
160   data.first = stack;
161   data.last = stack;
162   data.frames_symbolized = 0;
163   backtrace_pcinfo((backtrace_state *)state_, addr, SymbolizeCodePCInfoCallback,
164                    ErrorCallback, &data);
165   if (data.frames_symbolized > 0)
166     return true;
167   backtrace_syminfo((backtrace_state *)state_, addr, SymbolizeCodeCallback,
168                     ErrorCallback, &data);
169   return (data.frames_symbolized > 0);
170 }
171 
SymbolizeData(uptr addr,DataInfo * info)172 bool LibbacktraceSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
173   backtrace_syminfo((backtrace_state *)state_, addr, SymbolizeDataCallback,
174                     ErrorCallback, info);
175   return true;
176 }
177 
178 #else  // SANITIZER_LIBBACKTRACE
179 
get(LowLevelAllocator * alloc)180 LibbacktraceSymbolizer *LibbacktraceSymbolizer::get(LowLevelAllocator *alloc) {
181   return 0;
182 }
183 
SymbolizePC(uptr addr,SymbolizedStack * stack)184 bool LibbacktraceSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
185   (void)state_;
186   return false;
187 }
188 
SymbolizeData(uptr addr,DataInfo * info)189 bool LibbacktraceSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
190   return false;
191 }
192 
193 #endif  // SANITIZER_LIBBACKTRACE
194 
DemangleAlloc(const char * name,bool always_alloc)195 static char *DemangleAlloc(const char *name, bool always_alloc) {
196 #if SANITIZER_LIBBACKTRACE && SANITIZER_CP_DEMANGLE
197   if (char *demangled = CplusV3Demangle(name))
198     return demangled;
199 #endif
200   if (always_alloc)
201     return internal_strdup(name);
202   return 0;
203 }
204 
Demangle(const char * name)205 const char *LibbacktraceSymbolizer::Demangle(const char *name) {
206   return DemangleAlloc(name, /*always_alloc*/ false);
207 }
208 
209 }  // namespace __sanitizer
210