1//===-- sanitizer_symbolizer_libbacktrace.cpp -----------------------------===//
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// This file is shared between AddressSanitizer and ThreadSanitizer
10// run-time libraries.
11// Libbacktrace implementation of symbolizer parts.
12//===----------------------------------------------------------------------===//
13
14#include "sanitizer_platform.h"
15
16#include "sanitizer_internal_defs.h"
17#include "sanitizer_symbolizer.h"
18#include "sanitizer_symbolizer_libbacktrace.h"
19
20#if SANITIZER_LIBBACKTRACE
21# include "backtrace-supported.h"
22# if SANITIZER_POSIX && BACKTRACE_SUPPORTED && !BACKTRACE_USES_MALLOC
23#  include "backtrace.h"
24#  if SANITIZER_CP_DEMANGLE
25#   undef ARRAY_SIZE
26#   include "demangle.h"
27#  endif
28# else
29#  define SANITIZER_LIBBACKTRACE 0
30# endif
31#endif
32
33namespace __sanitizer {
34
35static char *DemangleAlloc(const char *name, bool always_alloc);
36
37#if SANITIZER_LIBBACKTRACE
38
39namespace {
40
41# if SANITIZER_CP_DEMANGLE
42struct CplusV3DemangleData {
43  char *buf;
44  uptr size, allocated;
45};
46
47extern "C" {
48static void CplusV3DemangleCallback(const char *s, size_t l, void *vdata) {
49  CplusV3DemangleData *data = (CplusV3DemangleData *)vdata;
50  uptr needed = data->size + l + 1;
51  if (needed > data->allocated) {
52    data->allocated *= 2;
53    if (needed > data->allocated)
54      data->allocated = needed;
55    char *buf = (char *)InternalAlloc(data->allocated);
56    if (data->buf) {
57      internal_memcpy(buf, data->buf, data->size);
58      InternalFree(data->buf);
59    }
60    data->buf = buf;
61  }
62  internal_memcpy(data->buf + data->size, s, l);
63  data->buf[data->size + l] = '\0';
64  data->size += l;
65}
66}  // extern "C"
67
68char *CplusV3Demangle(const char *name) {
69  CplusV3DemangleData data;
70  data.buf = 0;
71  data.size = 0;
72  data.allocated = 0;
73  if (cplus_demangle_v3_callback(name, DMGL_PARAMS | DMGL_ANSI,
74                                 CplusV3DemangleCallback, &data)) {
75    if (data.size + 64 > data.allocated)
76      return data.buf;
77    char *buf = internal_strdup(data.buf);
78    InternalFree(data.buf);
79    return buf;
80  }
81  if (data.buf)
82    InternalFree(data.buf);
83  return 0;
84}
85# endif  // SANITIZER_CP_DEMANGLE
86
87struct SymbolizeCodeCallbackArg {
88  SymbolizedStack *first;
89  SymbolizedStack *last;
90  uptr frames_symbolized;
91
92  AddressInfo *get_new_frame(uintptr_t addr) {
93    CHECK(last);
94    if (frames_symbolized > 0) {
95      SymbolizedStack *cur = SymbolizedStack::New(addr);
96      AddressInfo *info = &cur->info;
97      info->FillModuleInfo(first->info.module, first->info.module_offset,
98                           first->info.module_arch);
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
108extern "C" {
109static 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
124static 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
134static 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
144static void ErrorCallback(void *, const char *, int) {}
145}  // extern "C"
146
147}  // namespace
148
149LibbacktraceSymbolizer *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
158bool 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
172bool 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
180LibbacktraceSymbolizer *LibbacktraceSymbolizer::get(LowLevelAllocator *alloc) {
181  return 0;
182}
183
184bool LibbacktraceSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
185  (void)state_;
186  return false;
187}
188
189bool LibbacktraceSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
190  return false;
191}
192
193#endif  // SANITIZER_LIBBACKTRACE
194
195static 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
205const char *LibbacktraceSymbolizer::Demangle(const char *name) {
206  return DemangleAlloc(name, /*always_alloc*/ false);
207}
208
209}  // namespace __sanitizer
210