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 <unwindstack/DwarfLocation.h>
30 #include <unwindstack/DwarfMemory.h>
31 #include <unwindstack/DwarfSection.h>
32 #include <unwindstack/DwarfStructs.h>
33 #include <unwindstack/Elf.h>
34 #include <unwindstack/ElfInterface.h>
35 #include <unwindstack/Log.h>
36 #include <unwindstack/Memory.h>
37
38 #include "ArmExidx.h"
39 #include "DwarfOp.h"
40 #include "ElfInterfaceArm.h"
41
42 namespace unwindstack {
43
PrintSignedValue(int64_t value)44 void PrintSignedValue(int64_t value) {
45 if (value < 0) {
46 printf("- %" PRId64, -value);
47 } else if (value > 0) {
48 printf("+ %" PRId64, value);
49 }
50 }
51
PrintExpression(Memory * memory,uint8_t class_type,uint64_t end,uint64_t length)52 void PrintExpression(Memory* memory, uint8_t class_type, uint64_t end, uint64_t length) {
53 std::vector<std::string> lines;
54 DwarfMemory dwarf_memory(memory);
55 if (class_type == ELFCLASS32) {
56 DwarfOp<uint32_t> op(&dwarf_memory, nullptr);
57 op.GetLogInfo(end - length, end, &lines);
58 } else {
59 DwarfOp<uint64_t> op(&dwarf_memory, nullptr);
60 op.GetLogInfo(end - length, end, &lines);
61 }
62 for (auto& line : lines) {
63 printf(" %s\n", line.c_str());
64 }
65 }
66
PrintRegInformation(DwarfSection * section,Memory * memory,uint64_t pc,uint8_t class_type)67 void PrintRegInformation(DwarfSection* section, Memory* memory, uint64_t pc, uint8_t class_type) {
68 const DwarfFde* fde = section->GetFdeFromPc(pc);
69 if (fde == nullptr) {
70 printf(" No fde found.\n");
71 return;
72 }
73
74 dwarf_loc_regs_t regs;
75 if (!section->GetCfaLocationInfo(pc, fde, ®s)) {
76 printf(" Cannot get location information.\n");
77 return;
78 }
79
80 std::vector<std::pair<uint32_t, DwarfLocation>> loc_regs;
81 for (auto& loc : regs) {
82 loc_regs.push_back(loc);
83 }
84 std::sort(loc_regs.begin(), loc_regs.end(), [](auto a, auto b) {
85 if (a.first == CFA_REG) {
86 return true;
87 } else if (b.first == CFA_REG) {
88 return false;
89 }
90 return a.first < b.first;
91 });
92
93 for (auto& entry : loc_regs) {
94 const DwarfLocation* loc = &entry.second;
95 if (entry.first == CFA_REG) {
96 printf(" cfa = ");
97 } else {
98 printf(" r%d = ", entry.first);
99 }
100 switch (loc->type) {
101 case DWARF_LOCATION_OFFSET:
102 printf("[cfa ");
103 PrintSignedValue(loc->values[0]);
104 printf("]\n");
105 break;
106
107 case DWARF_LOCATION_VAL_OFFSET:
108 printf("cfa ");
109 PrintSignedValue(loc->values[0]);
110 printf("\n");
111 break;
112
113 case DWARF_LOCATION_REGISTER:
114 printf("r%" PRId64 " ", loc->values[0]);
115 PrintSignedValue(loc->values[1]);
116 printf("\n");
117 break;
118
119 case DWARF_LOCATION_EXPRESSION: {
120 printf("EXPRESSION\n");
121 PrintExpression(memory, class_type, loc->values[1], loc->values[0]);
122 break;
123 }
124
125 case DWARF_LOCATION_VAL_EXPRESSION: {
126 printf("VAL EXPRESSION\n");
127 PrintExpression(memory, class_type, loc->values[1], loc->values[0]);
128 break;
129 }
130
131 case DWARF_LOCATION_UNDEFINED:
132 printf("undefine\n");
133 break;
134
135 case DWARF_LOCATION_INVALID:
136 printf("INVALID\n");
137 break;
138 }
139 }
140 }
141
PrintArmRegInformation(ElfInterfaceArm * interface,uint64_t pc)142 void PrintArmRegInformation(ElfInterfaceArm* interface, uint64_t pc) {
143 printf("\nArm exidx:\n");
144 uint64_t entry_offset;
145 if (!interface->FindEntry(pc, &entry_offset)) {
146 return;
147 }
148
149 ArmExidx arm(nullptr, interface->memory(), nullptr);
150
151 log_to_stdout(true);
152 arm.set_log(ARM_LOG_BY_REG);
153 arm.set_log_skip_execution(true);
154 arm.set_log_indent(1);
155 if (!arm.ExtractEntryData(entry_offset)) {
156 if (arm.status() != ARM_STATUS_NO_UNWIND) {
157 printf(" Error trying to extract data.\n");
158 }
159 return;
160 }
161 if (arm.data()->size() != 0 && arm.Eval()) {
162 arm.LogByReg();
163 } else {
164 printf(" Error tring to evaluate exidx data.\n");
165 }
166 }
167
GetInfo(const char * file,uint64_t offset,uint64_t pc)168 int GetInfo(const char* file, uint64_t offset, uint64_t pc) {
169 Elf elf(Memory::CreateFileMemory(file, offset).release());
170 if (!elf.Init() || !elf.valid()) {
171 printf("%s is not a valid elf file.\n", file);
172 return 1;
173 }
174
175 ElfInterface* interface = elf.interface();
176 uint64_t load_bias = elf.GetLoadBias();
177 if (pc < load_bias) {
178 printf("PC is less than load bias.\n");
179 return 1;
180 }
181
182 std::string soname(elf.GetSoname());
183 if (!soname.empty()) {
184 printf("Soname: %s\n\n", soname.c_str());
185 }
186
187 printf("PC 0x%" PRIx64, pc);
188 std::string function_name;
189 uint64_t function_offset;
190 if (elf.GetFunctionName(pc, &function_name, &function_offset)) {
191 printf(" (%s)", function_name.c_str());
192 }
193 printf(":\n");
194
195 if (elf.machine_type() == EM_ARM) {
196 PrintArmRegInformation(reinterpret_cast<ElfInterfaceArm*>(interface), pc - load_bias);
197 }
198
199 DwarfSection* section = interface->eh_frame();
200 if (section != nullptr) {
201 printf("\neh_frame:\n");
202 PrintRegInformation(section, elf.memory(), pc, elf.class_type());
203 } else {
204 printf("\nno eh_frame information\n");
205 }
206
207 section = interface->debug_frame();
208 if (section != nullptr) {
209 printf("\ndebug_frame:\n");
210 PrintRegInformation(section, elf.memory(), pc, elf.class_type());
211 printf("\n");
212 } else {
213 printf("\nno debug_frame information\n");
214 }
215
216 // If there is a gnu_debugdata interface, dump the information for that.
217 ElfInterface* gnu_debugdata_interface = elf.gnu_debugdata_interface();
218 if (gnu_debugdata_interface != nullptr) {
219 section = gnu_debugdata_interface->eh_frame();
220 if (section != nullptr) {
221 printf("\ngnu_debugdata (eh_frame):\n");
222 PrintRegInformation(section, gnu_debugdata_interface->memory(), pc, elf.class_type());
223 printf("\n");
224 } else {
225 printf("\nno gnu_debugdata (eh_frame)\n");
226 }
227
228 section = gnu_debugdata_interface->debug_frame();
229 if (section != nullptr) {
230 printf("\ngnu_debugdata (debug_frame):\n");
231 PrintRegInformation(section, gnu_debugdata_interface->memory(), pc, elf.class_type());
232 printf("\n");
233 } else {
234 printf("\nno gnu_debugdata (debug_frame)\n");
235 }
236 } else {
237 printf("\nno valid gnu_debugdata information\n");
238 }
239
240 return 0;
241 }
242
243 } // namespace unwindstack
244
main(int argc,char ** argv)245 int main(int argc, char** argv) {
246 if (argc != 3 && argc != 4) {
247 printf("Usage: unwind_reg_info ELF_FILE PC [OFFSET]\n");
248 printf(" ELF_FILE\n");
249 printf(" The path to an elf file.\n");
250 printf(" PC\n");
251 printf(" The pc for which the register information should be obtained.\n");
252 printf(" OFFSET\n");
253 printf(" Use the offset into the ELF file as the beginning of the elf.\n");
254 return 1;
255 }
256
257 struct stat st;
258 if (stat(argv[1], &st) == -1) {
259 printf("Cannot stat %s: %s\n", argv[1], strerror(errno));
260 return 1;
261 }
262 if (!S_ISREG(st.st_mode)) {
263 printf("%s is not a regular file.\n", argv[1]);
264 return 1;
265 }
266
267 uint64_t pc = 0;
268 char* end;
269 pc = strtoull(argv[2], &end, 16);
270 if (*end != '\0') {
271 printf("Malformed OFFSET value: %s\n", argv[2]);
272 return 1;
273 }
274
275 uint64_t offset = 0;
276 if (argc == 4) {
277 char* end;
278 offset = strtoull(argv[3], &end, 16);
279 if (*end != '\0') {
280 printf("Malformed OFFSET value: %s\n", argv[3]);
281 return 1;
282 }
283 }
284
285 return unwindstack::GetInfo(argv[1], offset, pc);
286 }
287