Cross Reference: /freebsd-11-stable/contrib/llvm-project/libunwind/src/UnwindLevel1.c

1//===------------------------- UnwindLevel1.c -----------------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//

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34
35static _Unwind_Reason_Code
36unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
37 unw_init_local(cursor, uc);
38
39 // Walk each frame looking for a place to stop.
40 bool handlerNotFound = true;
41 while (handlerNotFound) {

42 // Ask libuwind to get next frame (skip over first which is

42 // Ask libunwind to get next frame (skip over first which is

43 // _Unwind_RaiseException).
44 int stepResult = unw_step(cursor);
45 if (stepResult == 0) {
46 _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "

47 "bottom => _URC_END_OF_STACK\n",

47 "bottom => _URC_END_OF_STACK",

48 (void *)exception_object);
49 return _URC_END_OF_STACK;
50 } else if (stepResult < 0) {
51 _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => "

52 "_URC_FATAL_PHASE1_ERROR\n",

52 "_URC_FATAL_PHASE1_ERROR",

53 (void *)exception_object);
54 return _URC_FATAL_PHASE1_ERROR;
55 }
56
57 // See if frame has code to run (has personality routine).
58 unw_proc_info_t frameInfo;
59 unw_word_t sp;
60 if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
61 _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info "

62 "failed => _URC_FATAL_PHASE1_ERROR\n",

62 "failed => _URC_FATAL_PHASE1_ERROR",

63 (void *)exception_object);
64 return _URC_FATAL_PHASE1_ERROR;
65 }
66
67 // When tracing, print state information.
68 if (_LIBUNWIND_TRACING_UNWINDING) {
69 char functionBuf[512];
70 const char *functionName = functionBuf;
71 unw_word_t offset;
72 if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
73 &offset) != UNW_ESUCCESS) ||
74 (frameInfo.start_ip + offset > frameInfo.end_ip))
75 functionName = ".anonymous.";
76 unw_word_t pc;
77 unw_get_reg(cursor, UNW_REG_IP, &pc);
78 _LIBUNWIND_TRACE_UNWINDING(
79 "unwind_phase1(ex_ojb=%p): pc=0x%" PRIx64 ", start_ip=0x%" PRIx64

80 ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64 "\n",

80 ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64 "",

81 (void *)exception_object, pc, frameInfo.start_ip, functionName,
82 frameInfo.lsda, frameInfo.handler);
83 }
84
85 // If there is a personality routine, ask it if it will want to stop at
86 // this frame.
87 if (frameInfo.handler != 0) {
88 __personality_routine p =
89 (__personality_routine)(long)(frameInfo.handler);
90 _LIBUNWIND_TRACE_UNWINDING(

91 "unwind_phase1(ex_ojb=%p): calling personality function %p\n",

91 "unwind_phase1(ex_ojb=%p): calling personality function %p",

92 (void *)exception_object, (void *)(uintptr_t)p);
93 _Unwind_Reason_Code personalityResult =
94 (*p)(1, _UA_SEARCH_PHASE, exception_object->exception_class,
95 exception_object, (struct _Unwind_Context *)(cursor));
96 switch (personalityResult) {
97 case _URC_HANDLER_FOUND:
98 // found a catch clause or locals that need destructing in this frame
99 // stop search and remember stack pointer at the frame
100 handlerNotFound = false;
101 unw_get_reg(cursor, UNW_REG_SP, &sp);
102 exception_object->private_2 = (uintptr_t)sp;
103 _LIBUNWIND_TRACE_UNWINDING(

104 "unwind_phase1(ex_ojb=%p): _URC_HANDLER_FOUND \n",

104 "unwind_phase1(ex_ojb=%p): _URC_HANDLER_FOUND",

105 (void *)exception_object);
106 return _URC_NO_REASON;
107
108 case _URC_CONTINUE_UNWIND:
109 _LIBUNWIND_TRACE_UNWINDING(

110 "unwind_phase1(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",

110 "unwind_phase1(ex_ojb=%p): _URC_CONTINUE_UNWIND",

111 (void *)exception_object);
112 // continue unwinding
113 break;
114
115 default:
116 // something went wrong
117 _LIBUNWIND_TRACE_UNWINDING(

118 "unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR\n",

118 "unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR",

119 (void *)exception_object);
120 return _URC_FATAL_PHASE1_ERROR;
121 }
122 }
123 }
124 return _URC_NO_REASON;
125}
126
127
128static _Unwind_Reason_Code
129unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
130 unw_init_local(cursor, uc);
131

132 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n",

132 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)",

133 (void *)exception_object);
134
135 // Walk each frame until we reach where search phase said to stop.
136 while (true) {
137

138 // Ask libuwind to get next frame (skip over first which is

138 // Ask libunwind to get next frame (skip over first which is

139 // _Unwind_RaiseException).
140 int stepResult = unw_step(cursor);
141 if (stepResult == 0) {
142 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "

143 "bottom => _URC_END_OF_STACK\n",

143 "bottom => _URC_END_OF_STACK",

144 (void *)exception_object);
145 return _URC_END_OF_STACK;
146 } else if (stepResult < 0) {
147 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => "

148 "_URC_FATAL_PHASE1_ERROR\n",

148 "_URC_FATAL_PHASE1_ERROR",

149 (void *)exception_object);
150 return _URC_FATAL_PHASE2_ERROR;
151 }
152
153 // Get info about this frame.
154 unw_word_t sp;
155 unw_proc_info_t frameInfo;
156 unw_get_reg(cursor, UNW_REG_SP, &sp);
157 if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
158 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info "

159 "failed => _URC_FATAL_PHASE1_ERROR\n",

159 "failed => _URC_FATAL_PHASE1_ERROR",

160 (void *)exception_object);
161 return _URC_FATAL_PHASE2_ERROR;
162 }
163
164 // When tracing, print state information.
165 if (_LIBUNWIND_TRACING_UNWINDING) {
166 char functionBuf[512];
167 const char *functionName = functionBuf;
168 unw_word_t offset;
169 if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
170 &offset) != UNW_ESUCCESS) ||
171 (frameInfo.start_ip + offset > frameInfo.end_ip))
172 functionName = ".anonymous.";
173 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): start_ip=0x%" PRIx64
174 ", func=%s, sp=0x%" PRIx64 ", lsda=0x%" PRIx64

175 ", personality=0x%" PRIx64 "\n",

175 ", personality=0x%" PRIx64,

176 (void *)exception_object, frameInfo.start_ip,
177 functionName, sp, frameInfo.lsda,
178 frameInfo.handler);
179 }
180
181 // If there is a personality routine, tell it we are unwinding.
182 if (frameInfo.handler != 0) {
183 __personality_routine p =

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189 }
190 _Unwind_Reason_Code personalityResult =
191 (*p)(1, action, exception_object->exception_class, exception_object,
192 (struct _Unwind_Context *)(cursor));
193 switch (personalityResult) {
194 case _URC_CONTINUE_UNWIND:
195 // Continue unwinding
196 _LIBUNWIND_TRACE_UNWINDING(

197 "unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",

197 "unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND",

198 (void *)exception_object);
199 if (sp == exception_object->private_2) {
200 // Phase 1 said we would stop at this frame, but we did not...
201 _LIBUNWIND_ABORT("during phase1 personality function said it would "
202 "stop here, but now in phase2 it did not stop here");
203 }
204 break;
205 case _URC_INSTALL_CONTEXT:
206 _LIBUNWIND_TRACE_UNWINDING(

207 "unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT\n",

207 "unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT",

208 (void *)exception_object);
209 // Personality routine says to transfer control to landing pad.
210 // We may get control back if landing pad calls _Unwind_Resume().
211 if (_LIBUNWIND_TRACING_UNWINDING) {
212 unw_word_t pc;
213 unw_get_reg(cursor, UNW_REG_IP, &pc);
214 unw_get_reg(cursor, UNW_REG_SP, &sp);
215 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering "
216 "user code with ip=0x%" PRIx64

217 ", sp=0x%" PRIx64 "\n",

217 ", sp=0x%" PRIx64,

218 (void *)exception_object, pc, sp);
219 }
220 unw_resume(cursor);
221 // unw_resume() only returns if there was an error.
222 return _URC_FATAL_PHASE2_ERROR;
223 default:
224 // Personality routine returned an unknown result code.
225 _LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",

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242
243 // Walk each frame until we reach where search phase said to stop
244 while (unw_step(cursor) > 0) {
245
246 // Update info about this frame.
247 unw_proc_info_t frameInfo;
248 if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
249 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): unw_step "

250 "failed => _URC_END_OF_STACK\n",

250 "failed => _URC_END_OF_STACK",

251 (void *)exception_object);
252 return _URC_FATAL_PHASE2_ERROR;
253 }
254
255 // When tracing, print state information.
256 if (_LIBUNWIND_TRACING_UNWINDING) {
257 char functionBuf[512];
258 const char *functionName = functionBuf;
259 unw_word_t offset;
260 if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
261 &offset) != UNW_ESUCCESS) ||
262 (frameInfo.start_ip + offset > frameInfo.end_ip))
263 functionName = ".anonymous.";
264 _LIBUNWIND_TRACE_UNWINDING(
265 "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIx64

266 ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64 "\n",

266 ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64,

267 (void *)exception_object, frameInfo.start_ip, functionName,
268 frameInfo.lsda, frameInfo.handler);
269 }
270
271 // Call stop function at each frame.
272 _Unwind_Action action =
273 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
274 _Unwind_Reason_Code stopResult =
275 (*stop)(1, action, exception_object->exception_class, exception_object,
276 (struct _Unwind_Context *)(cursor), stop_parameter);
277 _LIBUNWIND_TRACE_UNWINDING(

278 "unwind_phase2_forced(ex_ojb=%p): stop function returned %d\n",

278 "unwind_phase2_forced(ex_ojb=%p): stop function returned %d",

279 (void *)exception_object, stopResult);
280 if (stopResult != _URC_NO_REASON) {
281 _LIBUNWIND_TRACE_UNWINDING(

282 "unwind_phase2_forced(ex_ojb=%p): stopped by stop function\n",

282 "unwind_phase2_forced(ex_ojb=%p): stopped by stop function",

283 (void *)exception_object);
284 return _URC_FATAL_PHASE2_ERROR;
285 }
286
287 // If there is a personality routine, tell it we are unwinding.
288 if (frameInfo.handler != 0) {
289 __personality_routine p =
290 (__personality_routine)(long)(frameInfo.handler);
291 _LIBUNWIND_TRACE_UNWINDING(

292 "unwind_phase2_forced(ex_ojb=%p): calling personality function %p\n",

292 "unwind_phase2_forced(ex_ojb=%p): calling personality function %p",

293 (void *)exception_object, (void *)(uintptr_t)p);
294 _Unwind_Reason_Code personalityResult =
295 (*p)(1, action, exception_object->exception_class, exception_object,
296 (struct _Unwind_Context *)(cursor));
297 switch (personalityResult) {
298 case _URC_CONTINUE_UNWIND:
299 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
300 "personality returned "

301 "_URC_CONTINUE_UNWIND\n",

301 "_URC_CONTINUE_UNWIND",

302 (void *)exception_object);
303 // Destructors called, continue unwinding
304 break;
305 case _URC_INSTALL_CONTEXT:
306 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
307 "personality returned "

308 "_URC_INSTALL_CONTEXT\n",

308 "_URC_INSTALL_CONTEXT",

309 (void *)exception_object);
310 // We may get control back if landing pad calls _Unwind_Resume().
311 unw_resume(cursor);
312 break;
313 default:
314 // Personality routine returned an unknown result code.
315 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
316 "personality returned %d, "

317 "_URC_FATAL_PHASE2_ERROR\n",

317 "_URC_FATAL_PHASE2_ERROR",

318 (void *)exception_object, personalityResult);
319 return _URC_FATAL_PHASE2_ERROR;
320 }
321 }
322 }
323
324 // Call stop function one last time and tell it we've reached the end
325 // of the stack.
326 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "

327 "function with _UA_END_OF_STACK\n",

327 "function with _UA_END_OF_STACK",

328 (void *)exception_object);
329 _Unwind_Action lastAction =
330 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
331 (*stop)(1, lastAction, exception_object->exception_class, exception_object,
332 (struct _Unwind_Context *)(cursor), stop_parameter);
333
334 // Clean up phase did not resume at the frame that the search phase said it
335 // would.
336 return _URC_FATAL_PHASE2_ERROR;
337}
338
339
340/// Called by __cxa_throw. Only returns if there is a fatal error.
341_LIBUNWIND_EXPORT _Unwind_Reason_Code
342_Unwind_RaiseException(_Unwind_Exception *exception_object) {

343 _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)\n",

343 _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)",

344 (void *)exception_object);
345 unw_context_t uc;
346 unw_cursor_t cursor;
347 unw_getcontext(&uc);
348
349 // Mark that this is a non-forced unwind, so _Unwind_Resume()
350 // can do the right thing.
351 exception_object->private_1 = 0;

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370/// geneated user code. All other _Unwind_* routines are called
371/// by the C++ runtime __cxa_* routines.
372///
373/// Note: re-throwing an exception (as opposed to continuing the unwind)
374/// is implemented by having the code call __cxa_rethrow() which
375/// in turn calls _Unwind_Resume_or_Rethrow().
376_LIBUNWIND_EXPORT void
377_Unwind_Resume(_Unwind_Exception *exception_object) {

378 _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)\n", (void *)exception_object);

378 _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)", (void *)exception_object);

379 unw_context_t uc;
380 unw_cursor_t cursor;
381 unw_getcontext(&uc);
382
383 if (exception_object->private_1 != 0)
384 unwind_phase2_forced(&uc, &cursor, exception_object,
385 (_Unwind_Stop_Fn) exception_object->private_1,
386 (void *)exception_object->private_2);

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394
395
396/// Not used by C++.
397/// Unwinds stack, calling "stop" function at each frame.
398/// Could be used to implement longjmp().
399_LIBUNWIND_EXPORT _Unwind_Reason_Code
400_Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
401 _Unwind_Stop_Fn stop, void *stop_parameter) {

402 _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)\n",

402 _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)",

403 (void *)exception_object, (void *)(uintptr_t)stop);
404 unw_context_t uc;
405 unw_cursor_t cursor;
406 unw_getcontext(&uc);
407
408 // Mark that this is a forced unwind, so _Unwind_Resume() can do
409 // the right thing.
410 exception_object->private_1 = (uintptr_t) stop;

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419_LIBUNWIND_EXPORT uintptr_t
420_Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
421 unw_cursor_t *cursor = (unw_cursor_t *)context;
422 unw_proc_info_t frameInfo;
423 uintptr_t result = 0;
424 if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
425 result = (uintptr_t)frameInfo.lsda;
426 _LIBUNWIND_TRACE_API(

427 "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR "\n",

427 "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR,

428 (void *)context, result);
429 if (result != 0) {
430 if (*((uint8_t *)result) != 0xFF)

431 _LIBUNWIND_DEBUG_LOG("lsda at 0x%" PRIxPTR " does not start with 0xFF\n",

431 _LIBUNWIND_DEBUG_LOG("lsda at 0x%" PRIxPTR " does not start with 0xFF",

432 result);
433 }
434 return result;
435}
436
437
438/// Called by personality handler during phase 2 to find the start of the
439/// function.
440_LIBUNWIND_EXPORT uintptr_t
441_Unwind_GetRegionStart(struct _Unwind_Context *context) {
442 unw_cursor_t *cursor = (unw_cursor_t *)context;
443 unw_proc_info_t frameInfo;
444 uintptr_t result = 0;
445 if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
446 result = (uintptr_t)frameInfo.start_ip;

447 _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR "\n",

447 _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR,

448 (void *)context, result);
449 return result;
450}
451
452
453/// Called by personality handler during phase 2 if a foreign exception
454// is caught.
455_LIBUNWIND_EXPORT void
456_Unwind_DeleteException(_Unwind_Exception *exception_object) {

457 _LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)\n",

457 _LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)",

458 (void *)exception_object);
459 if (exception_object->exception_cleanup != NULL)
460 (*exception_object->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT,
461 exception_object);
462}
463
464/// Called by personality handler during phase 2 to get register values.
465_LIBUNWIND_EXPORT uintptr_t
466_Unwind_GetGR(struct _Unwind_Context *context, int index) {
467 unw_cursor_t *cursor = (unw_cursor_t *)context;
468 unw_word_t result;
469 unw_get_reg(cursor, index, &result);

470 _LIBUNWIND_TRACE_API("_Unwind_GetGR(context=%p, reg=%d) => 0x%" PRIx64 "\n",

470 _LIBUNWIND_TRACE_API("_Unwind_GetGR(context=%p, reg=%d) => 0x%" PRIx64,

471 (void *)context, index, (uint64_t)result);
472 return (uintptr_t)result;
473}
474
475/// Called by personality handler during phase 2 to alter register values.
476_LIBUNWIND_EXPORT void _Unwind_SetGR(struct _Unwind_Context *context, int index,
477 uintptr_t value) {
478 _LIBUNWIND_TRACE_API("_Unwind_SetGR(context=%p, reg=%d, value=0x%0" PRIx64

479 ")\n",

479 ")",

480 (void *)context, index, (uint64_t)value);
481 unw_cursor_t *cursor = (unw_cursor_t *)context;
482 unw_set_reg(cursor, index, value);
483}
484
485/// Called by personality handler during phase 2 to get instruction pointer.
486_LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
487 unw_cursor_t *cursor = (unw_cursor_t *)context;
488 unw_word_t result;
489 unw_get_reg(cursor, UNW_REG_IP, &result);

490 _LIBUNWIND_TRACE_API("_Unwind_GetIP(context=%p) => 0x%" PRIx64 "\n",

490 _LIBUNWIND_TRACE_API("_Unwind_GetIP(context=%p) => 0x%" PRIx64,

491 (void *)context, (uint64_t)result);
492 return (uintptr_t)result;
493}
494
495/// Called by personality handler during phase 2 to alter instruction pointer,
496/// such as setting where the landing pad is, so _Unwind_Resume() will
497/// start executing in the landing pad.
498_LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context,
499 uintptr_t value) {

500 _LIBUNWIND_TRACE_API("_Unwind_SetIP(context=%p, value=0x%0" PRIx64 ")\n",

500 _LIBUNWIND_TRACE_API("_Unwind_SetIP(context=%p, value=0x%0" PRIx64 ")",