1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <elf.h>
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <inttypes.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/mman.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28
29 #include <algorithm>
30 #include <memory>
31 #include <string>
32 #include <utility>
33 #include <vector>
34
35 #include <unwindstack/DwarfLocation.h>
36 #include <unwindstack/DwarfMemory.h>
37 #include <unwindstack/DwarfSection.h>
38 #include <unwindstack/DwarfStructs.h>
39 #include <unwindstack/Elf.h>
40 #include <unwindstack/ElfInterface.h>
41 #include <unwindstack/Log.h>
42 #include <unwindstack/Memory.h>
43
44 #include "ArmExidx.h"
45 #include "DwarfOp.h"
46 #include "ElfInterfaceArm.h"
47
48 namespace unwindstack {
49
PrintSignedValue(int64_t value)50 void PrintSignedValue(int64_t value) {
51 if (value < 0) {
52 printf("- %" PRId64, -value);
53 } else if (value > 0) {
54 printf("+ %" PRId64, value);
55 }
56 }
57
PrintExpression(std::shared_ptr<Memory> & memory,uint8_t class_type,uint64_t end,uint64_t length)58 void PrintExpression(std::shared_ptr<Memory>& memory, uint8_t class_type, uint64_t end,
59 uint64_t length) {
60 std::vector<std::string> lines;
61 DwarfMemory dwarf_memory(memory);
62 if (class_type == ELFCLASS32) {
63 DwarfOp<uint32_t> op(&dwarf_memory, nullptr);
64 op.GetLogInfo(end - length, end, &lines);
65 } else {
66 DwarfOp<uint64_t> op(&dwarf_memory, nullptr);
67 op.GetLogInfo(end - length, end, &lines);
68 }
69 for (auto& line : lines) {
70 printf(" %s\n", line.c_str());
71 }
72 }
73
PrintRegInformation(DwarfSection * section,std::shared_ptr<Memory> && memory,uint64_t pc,uint8_t class_type,ArchEnum arch)74 void PrintRegInformation(DwarfSection* section, std::shared_ptr<Memory>&& memory, uint64_t pc,
75 uint8_t class_type, ArchEnum arch) {
76 const DwarfFde* fde = section->GetFdeFromPc(pc);
77 if (fde == nullptr) {
78 printf(" No fde found.\n");
79 return;
80 }
81
82 DwarfLocations regs;
83 if (!section->GetCfaLocationInfo(pc, fde, ®s, arch)) {
84 printf(" Cannot get location information.\n");
85 return;
86 }
87
88 std::vector<std::pair<uint32_t, DwarfLocation>> loc_regs;
89 for (auto& loc : regs) {
90 loc_regs.push_back(loc);
91 }
92 std::sort(loc_regs.begin(), loc_regs.end(), [](auto a, auto b) {
93 if (a.first == CFA_REG) {
94 return true;
95 } else if (b.first == CFA_REG) {
96 return false;
97 }
98 return a.first < b.first;
99 });
100
101 for (auto& entry : loc_regs) {
102 const DwarfLocation* loc = &entry.second;
103 if (entry.first == CFA_REG) {
104 printf(" cfa = ");
105 } else {
106 printf(" r%d = ", entry.first);
107 }
108 switch (loc->type) {
109 case DWARF_LOCATION_OFFSET:
110 printf("[cfa ");
111 PrintSignedValue(loc->values[0]);
112 printf("]\n");
113 break;
114
115 case DWARF_LOCATION_VAL_OFFSET:
116 printf("cfa ");
117 PrintSignedValue(loc->values[0]);
118 printf("\n");
119 break;
120
121 case DWARF_LOCATION_REGISTER:
122 printf("r%" PRId64 " ", loc->values[0]);
123 PrintSignedValue(loc->values[1]);
124 printf("\n");
125 break;
126
127 case DWARF_LOCATION_EXPRESSION: {
128 printf("EXPRESSION\n");
129 PrintExpression(memory, class_type, loc->values[1], loc->values[0]);
130 break;
131 }
132
133 case DWARF_LOCATION_VAL_EXPRESSION: {
134 printf("VAL EXPRESSION\n");
135 PrintExpression(memory, class_type, loc->values[1], loc->values[0]);
136 break;
137 }
138
139 case DWARF_LOCATION_PSEUDO_REGISTER: {
140 printf("%" PRId64 " (pseudo)\n", loc->values[0]);
141 break;
142 }
143
144 case DWARF_LOCATION_UNDEFINED:
145 printf("undefine\n");
146 break;
147
148 case DWARF_LOCATION_INVALID:
149 printf("INVALID\n");
150 break;
151 }
152 }
153 }
154
PrintArmRegInformation(ElfInterfaceArm * interface,uint64_t pc)155 void PrintArmRegInformation(ElfInterfaceArm* interface, uint64_t pc) {
156 printf("\nArm exidx:\n");
157 uint64_t entry_offset;
158 if (!interface->FindEntry(pc, &entry_offset)) {
159 return;
160 }
161
162 ArmExidx arm(nullptr, interface->memory().get(), nullptr);
163
164 arm.set_log(ARM_LOG_BY_REG);
165 arm.set_log_skip_execution(true);
166 arm.set_log_indent(1);
167 if (!arm.ExtractEntryData(entry_offset)) {
168 if (arm.status() != ARM_STATUS_NO_UNWIND) {
169 printf(" Error trying to extract data.\n");
170 }
171 return;
172 }
173 if (arm.data()->size() != 0 && arm.Eval()) {
174 arm.LogByReg();
175 } else {
176 printf(" Error tring to evaluate exidx data.\n");
177 }
178 }
179
GetInfo(const char * file,uint64_t offset,uint64_t pc)180 int GetInfo(const char* file, uint64_t offset, uint64_t pc) {
181 auto elf_memory = Memory::CreateFileMemory(file, offset);
182 Elf elf(elf_memory);
183 if (!elf.Init() || !elf.valid()) {
184 printf("%s is not a valid elf file.\n", file);
185 return 1;
186 }
187
188 ElfInterface* interface = elf.interface();
189 uint64_t load_bias = elf.GetLoadBias();
190 if (pc < load_bias) {
191 printf("PC is less than load bias.\n");
192 return 1;
193 }
194
195 std::string soname(elf.GetSoname());
196 if (!soname.empty()) {
197 printf("Soname: %s\n\n", soname.c_str());
198 }
199
200 printf("PC 0x%" PRIx64, pc);
201 SharedString function_name;
202 uint64_t function_offset;
203 if (elf.GetFunctionName(pc, &function_name, &function_offset)) {
204 printf(" (%s)", function_name.c_str());
205 }
206 printf(":\n");
207
208 if (elf.machine_type() == EM_ARM) {
209 PrintArmRegInformation(reinterpret_cast<ElfInterfaceArm*>(interface), pc - load_bias);
210 }
211
212 DwarfSection* section = interface->eh_frame();
213 if (section != nullptr) {
214 printf("\neh_frame:\n");
215 PrintRegInformation(section, elf.memory(), pc, elf.class_type(), elf.arch());
216 } else {
217 printf("\nno eh_frame information\n");
218 }
219
220 section = interface->debug_frame();
221 if (section != nullptr) {
222 printf("\ndebug_frame:\n");
223 PrintRegInformation(section, elf.memory(), pc, elf.class_type(), elf.arch());
224 printf("\n");
225 } else {
226 printf("\nno debug_frame information\n");
227 }
228
229 // If there is a gnu_debugdata interface, dump the information for that.
230 ElfInterface* gnu_debugdata_interface = elf.gnu_debugdata_interface();
231 if (gnu_debugdata_interface != nullptr) {
232 section = gnu_debugdata_interface->eh_frame();
233 if (section != nullptr) {
234 printf("\ngnu_debugdata (eh_frame):\n");
235 PrintRegInformation(section, gnu_debugdata_interface->memory(), pc, elf.class_type(),
236 elf.arch());
237 printf("\n");
238 } else {
239 printf("\nno gnu_debugdata (eh_frame)\n");
240 }
241
242 section = gnu_debugdata_interface->debug_frame();
243 if (section != nullptr) {
244 printf("\ngnu_debugdata (debug_frame):\n");
245 PrintRegInformation(section, gnu_debugdata_interface->memory(), pc, elf.class_type(),
246 elf.arch());
247 printf("\n");
248 } else {
249 printf("\nno gnu_debugdata (debug_frame)\n");
250 }
251 } else {
252 printf("\nno valid gnu_debugdata information\n");
253 }
254
255 return 0;
256 }
257
258 } // namespace unwindstack
259
main(int argc,char ** argv)260 int main(int argc, char** argv) {
261 if (argc != 3 && argc != 4) {
262 printf("Usage: unwind_reg_info ELF_FILE PC [OFFSET]\n");
263 printf(" ELF_FILE\n");
264 printf(" The path to an elf file.\n");
265 printf(" PC\n");
266 printf(" The pc for which the register information should be obtained.\n");
267 printf(" OFFSET\n");
268 printf(" Use the offset into the ELF file as the beginning of the elf.\n");
269 return 1;
270 }
271
272 struct stat st;
273 if (stat(argv[1], &st) == -1) {
274 printf("Cannot stat %s: %s\n", argv[1], strerror(errno));
275 return 1;
276 }
277 if (!S_ISREG(st.st_mode)) {
278 printf("%s is not a regular file.\n", argv[1]);
279 return 1;
280 }
281
282 uint64_t pc = 0;
283 char* end;
284 pc = strtoull(argv[2], &end, 16);
285 if (*end != '\0') {
286 printf("Malformed OFFSET value: %s\n", argv[2]);
287 return 1;
288 }
289
290 uint64_t offset = 0;
291 if (argc == 4) {
292 char* end;
293 offset = strtoull(argv[3], &end, 16);
294 if (*end != '\0') {
295 printf("Malformed OFFSET value: %s\n", argv[3]);
296 return 1;
297 }
298 }
299
300 return unwindstack::GetInfo(argv[1], offset, pc);
301 }
302