1//===-- sanitizer_symbolizer_mac.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 various sanitizers' runtime libraries.
10//
11// Implementation of Mac-specific "atos" symbolizer.
12//===----------------------------------------------------------------------===//
13
14#include "sanitizer_platform.h"
15#if SANITIZER_MAC
16
17#include "sanitizer_allocator_internal.h"
18#include "sanitizer_mac.h"
19#include "sanitizer_symbolizer_mac.h"
20
21#include <dlfcn.h>
22#include <errno.h>
23#include <stdlib.h>
24#include <sys/wait.h>
25#include <unistd.h>
26#include <util.h>
27
28namespace __sanitizer {
29
30bool DlAddrSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
31  Dl_info info;
32  int result = dladdr((const void *)addr, &info);
33  if (!result) return false;
34
35  CHECK(addr >= reinterpret_cast<uptr>(info.dli_saddr));
36  stack->info.function_offset = addr - reinterpret_cast<uptr>(info.dli_saddr);
37  const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
38  if (!demangled) return false;
39  stack->info.function = internal_strdup(demangled);
40  return true;
41}
42
43bool DlAddrSymbolizer::SymbolizeData(uptr addr, DataInfo *datainfo) {
44  Dl_info info;
45  int result = dladdr((const void *)addr, &info);
46  if (!result) return false;
47  const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
48  datainfo->name = internal_strdup(demangled);
49  datainfo->start = (uptr)info.dli_saddr;
50  return true;
51}
52
53class AtosSymbolizerProcess : public SymbolizerProcess {
54 public:
55  explicit AtosSymbolizerProcess(const char *path, pid_t parent_pid)
56      : SymbolizerProcess(path, /*use_posix_spawn*/ true) {
57    // Put the string command line argument in the object so that it outlives
58    // the call to GetArgV.
59    internal_snprintf(pid_str_, sizeof(pid_str_), "%d", parent_pid);
60  }
61
62 private:
63  bool StartSymbolizerSubprocess() override {
64    // Configure sandbox before starting atos process.
65    return SymbolizerProcess::StartSymbolizerSubprocess();
66  }
67
68  bool ReachedEndOfOutput(const char *buffer, uptr length) const override {
69    return (length >= 1 && buffer[length - 1] == '\n');
70  }
71
72  void GetArgV(const char *path_to_binary,
73               const char *(&argv)[kArgVMax]) const override {
74    int i = 0;
75    argv[i++] = path_to_binary;
76    argv[i++] = "-p";
77    argv[i++] = &pid_str_[0];
78    if (GetMacosVersion() == MACOS_VERSION_MAVERICKS) {
79      // On Mavericks atos prints a deprecation warning which we suppress by
80      // passing -d. The warning isn't present on other OSX versions, even the
81      // newer ones.
82      argv[i++] = "-d";
83    }
84    argv[i++] = nullptr;
85  }
86
87  char pid_str_[16];
88};
89
90static bool ParseCommandOutput(const char *str, uptr addr, char **out_name,
91                               char **out_module, char **out_file, uptr *line,
92                               uptr *start_address) {
93  // Trim ending newlines.
94  char *trim;
95  ExtractTokenUpToDelimiter(str, "\n", &trim);
96
97  // The line from `atos` is in one of these formats:
98  //   myfunction (in library.dylib) (sourcefile.c:17)
99  //   myfunction (in library.dylib) + 0x1fe
100  //   myfunction (in library.dylib) + 15
101  //   0xdeadbeef (in library.dylib) + 0x1fe
102  //   0xdeadbeef (in library.dylib) + 15
103  //   0xdeadbeef (in library.dylib)
104  //   0xdeadbeef
105
106  const char *rest = trim;
107  char *symbol_name;
108  rest = ExtractTokenUpToDelimiter(rest, " (in ", &symbol_name);
109  if (rest[0] == '\0') {
110    InternalFree(symbol_name);
111    InternalFree(trim);
112    return false;
113  }
114
115  if (internal_strncmp(symbol_name, "0x", 2) != 0)
116    *out_name = symbol_name;
117  else
118    InternalFree(symbol_name);
119  rest = ExtractTokenUpToDelimiter(rest, ") ", out_module);
120
121  if (rest[0] == '(') {
122    if (out_file) {
123      rest++;
124      rest = ExtractTokenUpToDelimiter(rest, ":", out_file);
125      char *extracted_line_number;
126      rest = ExtractTokenUpToDelimiter(rest, ")", &extracted_line_number);
127      if (line) *line = (uptr)internal_atoll(extracted_line_number);
128      InternalFree(extracted_line_number);
129    }
130  } else if (rest[0] == '+') {
131    rest += 2;
132    uptr offset = internal_atoll(rest);
133    if (start_address) *start_address = addr - offset;
134  }
135
136  InternalFree(trim);
137  return true;
138}
139
140AtosSymbolizer::AtosSymbolizer(const char *path, LowLevelAllocator *allocator)
141    : process_(new(*allocator) AtosSymbolizerProcess(path, getpid())) {}
142
143bool AtosSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
144  if (!process_) return false;
145  if (addr == 0) return false;
146  char command[32];
147  internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
148  const char *buf = process_->SendCommand(command);
149  if (!buf) return false;
150  uptr line;
151  uptr start_address = AddressInfo::kUnknown;
152  if (!ParseCommandOutput(buf, addr, &stack->info.function, &stack->info.module,
153                          &stack->info.file, &line, &start_address)) {
154    process_ = nullptr;
155    return false;
156  }
157  stack->info.line = (int)line;
158
159  if (start_address == AddressInfo::kUnknown) {
160    // Fallback to dladdr() to get function start address if atos doesn't report
161    // it.
162    Dl_info info;
163    int result = dladdr((const void *)addr, &info);
164    if (result)
165      start_address = reinterpret_cast<uptr>(info.dli_saddr);
166  }
167
168  // Only assig to `function_offset` if we were able to get the function's
169  // start address.
170  if (start_address != AddressInfo::kUnknown) {
171    CHECK(addr >= start_address);
172    stack->info.function_offset = addr - start_address;
173  }
174  return true;
175}
176
177bool AtosSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
178  if (!process_) return false;
179  char command[32];
180  internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
181  const char *buf = process_->SendCommand(command);
182  if (!buf) return false;
183  if (!ParseCommandOutput(buf, addr, &info->name, &info->module, nullptr,
184                          nullptr, &info->start)) {
185    process_ = nullptr;
186    return false;
187  }
188  return true;
189}
190
191}  // namespace __sanitizer
192
193#endif  // SANITIZER_MAC
194