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_APPLE
16
17# include <dlfcn.h>
18# include <errno.h>
19# include <stdlib.h>
20# include <sys/wait.h>
21# include <unistd.h>
22# include <util.h>
23
24# include "sanitizer_allocator_internal.h"
25# include "sanitizer_mac.h"
26# include "sanitizer_symbolizer_mac.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 || !info.dli_sname) return false;
34
35 // Compute offset if possible. `dladdr()` doesn't always ensure that `addr >=
36 // sym_addr` so only compute the offset when this holds. Failure to find the
37 // function offset is not treated as a failure because it might still be
38 // possible to get the symbol name.
39 uptr sym_addr = reinterpret_cast<uptr>(info.dli_saddr);
40 if (addr >= sym_addr) {
41 stack->info.function_offset = addr - sym_addr;
42 }
43
44 const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
45 if (!demangled)
46 demangled = info.dli_sname;
47 stack->info.function = internal_strdup(demangled);
48 return true;
49}
50
51bool DlAddrSymbolizer::SymbolizeData(uptr addr, DataInfo *datainfo) {
52 Dl_info info;
53 int result = dladdr((const void *)addr, &info);
54 if (!result || !info.dli_sname) return false;
55 const char *demangled = DemangleSwiftAndCXX(info.dli_sname);
56 if (!demangled)
57 demangled = info.dli_sname;
58 datainfo->name = internal_strdup(demangled);
59 datainfo->start = (uptr)info.dli_saddr;
60 return true;
61}
62
63class AtosSymbolizerProcess final : public SymbolizerProcess {
64 public:
65 explicit AtosSymbolizerProcess(const char *path)
66 : SymbolizerProcess(path, /*use_posix_spawn*/ true) {
67 pid_str_[0] = '\0';
68 }
69
70 private:
71 bool StartSymbolizerSubprocess() override {
72 // Put the string command line argument in the object so that it outlives
73 // the call to GetArgV.
74 internal_snprintf(pid_str_, sizeof(pid_str_), "%d", (int)internal_getpid());
75
76 // Configure sandbox before starting atos process.
77 return SymbolizerProcess::StartSymbolizerSubprocess();
78 }
79
80 bool ReachedEndOfOutput(const char *buffer, uptr length) const override {
81 return (length >= 1 && buffer[length - 1] == '\n');
82 }
83
84 void GetArgV(const char *path_to_binary,
85 const char *(&argv)[kArgVMax]) const override {
86 int i = 0;
87 argv[i++] = path_to_binary;
88 argv[i++] = "-p";
89 argv[i++] = &pid_str_[0];
90 if (GetMacosAlignedVersion() == MacosVersion(10, 9)) {
91 // On Mavericks atos prints a deprecation warning which we suppress by
92 // passing -d. The warning isn't present on other OSX versions, even the
93 // newer ones.
94 argv[i++] = "-d";
95 }
96 argv[i++] = nullptr;
97 CHECK_LE(i, kArgVMax);
98 }
99
100 char pid_str_[16];
101};
102
103#undef K_ATOS_ENV_VAR
104
105static bool ParseCommandOutput(const char *str, uptr addr, char **out_name,
106 char **out_module, char **out_file, uptr *line,
107 uptr *start_address) {
108 // Trim ending newlines.
109 char *trim;
110 ExtractTokenUpToDelimiter(str, "\n", &trim);
111
112 // The line from `atos` is in one of these formats:
113 // myfunction (in library.dylib) (sourcefile.c:17)
114 // myfunction (in library.dylib) + 0x1fe
115 // myfunction (in library.dylib) + 15
116 // 0xdeadbeef (in library.dylib) + 0x1fe
117 // 0xdeadbeef (in library.dylib) + 15
118 // 0xdeadbeef (in library.dylib)
119 // 0xdeadbeef
120
121 const char *rest = trim;
122 char *symbol_name;
123 rest = ExtractTokenUpToDelimiter(rest, " (in ", &symbol_name);
124 if (rest[0] == '\0') {
125 InternalFree(symbol_name);
126 InternalFree(trim);
127 return false;
128 }
129
130 if (internal_strncmp(symbol_name, "0x", 2) != 0)
131 *out_name = symbol_name;
132 else
133 InternalFree(symbol_name);
134 rest = ExtractTokenUpToDelimiter(rest, ") ", out_module);
135
136 if (rest[0] == '(') {
137 if (out_file) {
138 rest++;
139 rest = ExtractTokenUpToDelimiter(rest, ":", out_file);
140 char *extracted_line_number;
141 rest = ExtractTokenUpToDelimiter(rest, ")", &extracted_line_number);
142 if (line) *line = (uptr)internal_atoll(extracted_line_number);
143 InternalFree(extracted_line_number);
144 }
145 } else if (rest[0] == '+') {
146 rest += 2;
147 uptr offset = internal_atoll(rest);
148 if (start_address) *start_address = addr - offset;
149 }
150
151 InternalFree(trim);
152 return true;
153}
154
155AtosSymbolizer::AtosSymbolizer(const char *path, LowLevelAllocator *allocator)
156 : process_(new (*allocator) AtosSymbolizerProcess(path)) {}
157
158bool AtosSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
159 if (!process_) return false;
160 if (addr == 0) return false;
161 char command[32];
162 internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
163 const char *buf = process_->SendCommand(command);
164 if (!buf) return false;
165 uptr line;
166 uptr start_address = AddressInfo::kUnknown;
167 if (!ParseCommandOutput(buf, addr, &stack->info.function, &stack->info.module,
168 &stack->info.file, &line, &start_address)) {
169 Report("WARNING: atos failed to symbolize address \"0x%zx\"\n", addr);
170 return false;
171 }
172 stack->info.line = (int)line;
173
174 if (start_address == AddressInfo::kUnknown) {
175 // Fallback to dladdr() to get function start address if atos doesn't report
176 // it.
177 Dl_info info;
178 int result = dladdr((const void *)addr, &info);
179 if (result)
180 start_address = reinterpret_cast<uptr>(info.dli_saddr);
181 }
182
183 // Only assign to `function_offset` if we were able to get the function's
184 // start address and we got a sensible `start_address` (dladdr doesn't always
185 // ensure that `addr >= sym_addr`).
186 if (start_address != AddressInfo::kUnknown && addr >= start_address) {
187 stack->info.function_offset = addr - start_address;
188 }
189 return true;
190}
191
192bool AtosSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
193 if (!process_) return false;
194 char command[32];
195 internal_snprintf(command, sizeof(command), "0x%zx\n", addr);
196 const char *buf = process_->SendCommand(command);
197 if (!buf) return false;
198 if (!ParseCommandOutput(buf, addr, &info->name, &info->module, nullptr,
199 nullptr, &info->start)) {
200 process_ = nullptr;
201 return false;
202 }
203 return true;
204}
205
206} // namespace __sanitizer
207
208#endif // SANITIZER_APPLE
209