1 //===----------------------------------------------------------------------===//
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 // C++ interface to lower levels of libunwind
9 //===----------------------------------------------------------------------===//
10
11 #ifndef __UNWINDCURSOR_HPP__
12 #define __UNWINDCURSOR_HPP__
13
14 #include "cet_unwind.h"
15 #include <stdint.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <unwind.h>
19
20 #ifdef _WIN32
21 #include <windows.h>
22 #include <ntverp.h>
23 #endif
24 #ifdef __APPLE__
25 #include <mach-o/dyld.h>
26 #endif
27 #ifdef _AIX
28 #include <dlfcn.h>
29 #include <sys/debug.h>
30 #include <sys/pseg.h>
31 #endif
32
33 #if defined(_LIBUNWIND_TARGET_LINUX) && \
34 (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_RISCV) || \
35 defined(_LIBUNWIND_TARGET_S390X))
36 #include <errno.h>
37 #include <signal.h>
38 #include <sys/syscall.h>
39 #include <sys/uio.h>
40 #include <unistd.h>
41 #define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
42 #endif
43
44 #include "AddressSpace.hpp"
45 #include "CompactUnwinder.hpp"
46 #include "config.h"
47 #include "DwarfInstructions.hpp"
48 #include "EHHeaderParser.hpp"
49 #include "libunwind.h"
50 #include "libunwind_ext.h"
51 #include "Registers.hpp"
52 #include "RWMutex.hpp"
53 #include "Unwind-EHABI.h"
54
55 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
56 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
57 // earlier) SDKs.
58 // MinGW-w64 has always provided this struct.
59 #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
60 !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
61 struct _DISPATCHER_CONTEXT {
62 ULONG64 ControlPc;
63 ULONG64 ImageBase;
64 PRUNTIME_FUNCTION FunctionEntry;
65 ULONG64 EstablisherFrame;
66 ULONG64 TargetIp;
67 PCONTEXT ContextRecord;
68 PEXCEPTION_ROUTINE LanguageHandler;
69 PVOID HandlerData;
70 PUNWIND_HISTORY_TABLE HistoryTable;
71 ULONG ScopeIndex;
72 ULONG Fill0;
73 };
74 #endif
75
76 struct UNWIND_INFO {
77 uint8_t Version : 3;
78 uint8_t Flags : 5;
79 uint8_t SizeOfProlog;
80 uint8_t CountOfCodes;
81 uint8_t FrameRegister : 4;
82 uint8_t FrameOffset : 4;
83 uint16_t UnwindCodes[2];
84 };
85
86 extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
87 int, _Unwind_Action, uint64_t, _Unwind_Exception *,
88 struct _Unwind_Context *);
89
90 #endif
91
92 namespace libunwind {
93
94 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
95 /// Cache of recently found FDEs.
96 template <typename A>
97 class _LIBUNWIND_HIDDEN DwarfFDECache {
98 typedef typename A::pint_t pint_t;
99 public:
100 static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
101 static pint_t findFDE(pint_t mh, pint_t pc);
102 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
103 static void removeAllIn(pint_t mh);
104 static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
105 unw_word_t ip_end,
106 unw_word_t fde, unw_word_t mh));
107
108 private:
109
110 struct entry {
111 pint_t mh;
112 pint_t ip_start;
113 pint_t ip_end;
114 pint_t fde;
115 };
116
117 // These fields are all static to avoid needing an initializer.
118 // There is only one instance of this class per process.
119 static RWMutex _lock;
120 #ifdef __APPLE__
121 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
122 static bool _registeredForDyldUnloads;
123 #endif
124 static entry *_buffer;
125 static entry *_bufferUsed;
126 static entry *_bufferEnd;
127 static entry _initialBuffer[64];
128 };
129
130 template <typename A>
131 typename DwarfFDECache<A>::entry *
132 DwarfFDECache<A>::_buffer = _initialBuffer;
133
134 template <typename A>
135 typename DwarfFDECache<A>::entry *
136 DwarfFDECache<A>::_bufferUsed = _initialBuffer;
137
138 template <typename A>
139 typename DwarfFDECache<A>::entry *
140 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
141
142 template <typename A>
143 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
144
145 template <typename A>
146 RWMutex DwarfFDECache<A>::_lock;
147
148 #ifdef __APPLE__
149 template <typename A>
150 bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
151 #endif
152
153 template <typename A>
findFDE(pint_t mh,pint_t pc)154 typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) {
155 pint_t result = 0;
156 _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
157 for (entry *p = _buffer; p < _bufferUsed; ++p) {
158 if ((mh == p->mh) || (mh == kSearchAll)) {
159 if ((p->ip_start <= pc) && (pc < p->ip_end)) {
160 result = p->fde;
161 break;
162 }
163 }
164 }
165 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
166 return result;
167 }
168
169 template <typename A>
add(pint_t mh,pint_t ip_start,pint_t ip_end,pint_t fde)170 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
171 pint_t fde) {
172 #if !defined(_LIBUNWIND_NO_HEAP)
173 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
174 if (_bufferUsed >= _bufferEnd) {
175 size_t oldSize = (size_t)(_bufferEnd - _buffer);
176 size_t newSize = oldSize * 4;
177 // Can't use operator new (we are below it).
178 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
179 memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
180 if (_buffer != _initialBuffer)
181 free(_buffer);
182 _buffer = newBuffer;
183 _bufferUsed = &newBuffer[oldSize];
184 _bufferEnd = &newBuffer[newSize];
185 }
186 _bufferUsed->mh = mh;
187 _bufferUsed->ip_start = ip_start;
188 _bufferUsed->ip_end = ip_end;
189 _bufferUsed->fde = fde;
190 ++_bufferUsed;
191 #ifdef __APPLE__
192 if (!_registeredForDyldUnloads) {
193 _dyld_register_func_for_remove_image(&dyldUnloadHook);
194 _registeredForDyldUnloads = true;
195 }
196 #endif
197 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
198 #endif
199 }
200
201 template <typename A>
removeAllIn(pint_t mh)202 void DwarfFDECache<A>::removeAllIn(pint_t mh) {
203 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
204 entry *d = _buffer;
205 for (const entry *s = _buffer; s < _bufferUsed; ++s) {
206 if (s->mh != mh) {
207 if (d != s)
208 *d = *s;
209 ++d;
210 }
211 }
212 _bufferUsed = d;
213 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
214 }
215
216 #ifdef __APPLE__
217 template <typename A>
dyldUnloadHook(const struct mach_header * mh,intptr_t)218 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
219 removeAllIn((pint_t) mh);
220 }
221 #endif
222
223 template <typename A>
iterateCacheEntries(void (* func)(unw_word_t ip_start,unw_word_t ip_end,unw_word_t fde,unw_word_t mh))224 void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
225 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
226 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
227 for (entry *p = _buffer; p < _bufferUsed; ++p) {
228 (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
229 }
230 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
231 }
232 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
233
234
235 #define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field))
236
237 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
238 template <typename A> class UnwindSectionHeader {
239 public:
UnwindSectionHeader(A & addressSpace,typename A::pint_t addr)240 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
241 : _addressSpace(addressSpace), _addr(addr) {}
242
version() const243 uint32_t version() const {
244 return _addressSpace.get32(_addr +
245 offsetof(unwind_info_section_header, version));
246 }
commonEncodingsArraySectionOffset() const247 uint32_t commonEncodingsArraySectionOffset() const {
248 return _addressSpace.get32(_addr +
249 offsetof(unwind_info_section_header,
250 commonEncodingsArraySectionOffset));
251 }
commonEncodingsArrayCount() const252 uint32_t commonEncodingsArrayCount() const {
253 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
254 commonEncodingsArrayCount));
255 }
personalityArraySectionOffset() const256 uint32_t personalityArraySectionOffset() const {
257 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
258 personalityArraySectionOffset));
259 }
personalityArrayCount() const260 uint32_t personalityArrayCount() const {
261 return _addressSpace.get32(
262 _addr + offsetof(unwind_info_section_header, personalityArrayCount));
263 }
indexSectionOffset() const264 uint32_t indexSectionOffset() const {
265 return _addressSpace.get32(
266 _addr + offsetof(unwind_info_section_header, indexSectionOffset));
267 }
indexCount() const268 uint32_t indexCount() const {
269 return _addressSpace.get32(
270 _addr + offsetof(unwind_info_section_header, indexCount));
271 }
272
273 private:
274 A &_addressSpace;
275 typename A::pint_t _addr;
276 };
277
278 template <typename A> class UnwindSectionIndexArray {
279 public:
UnwindSectionIndexArray(A & addressSpace,typename A::pint_t addr)280 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
281 : _addressSpace(addressSpace), _addr(addr) {}
282
functionOffset(uint32_t index) const283 uint32_t functionOffset(uint32_t index) const {
284 return _addressSpace.get32(
285 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
286 functionOffset));
287 }
secondLevelPagesSectionOffset(uint32_t index) const288 uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
289 return _addressSpace.get32(
290 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
291 secondLevelPagesSectionOffset));
292 }
lsdaIndexArraySectionOffset(uint32_t index) const293 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
294 return _addressSpace.get32(
295 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
296 lsdaIndexArraySectionOffset));
297 }
298
299 private:
300 A &_addressSpace;
301 typename A::pint_t _addr;
302 };
303
304 template <typename A> class UnwindSectionRegularPageHeader {
305 public:
UnwindSectionRegularPageHeader(A & addressSpace,typename A::pint_t addr)306 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
307 : _addressSpace(addressSpace), _addr(addr) {}
308
kind() const309 uint32_t kind() const {
310 return _addressSpace.get32(
311 _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
312 }
entryPageOffset() const313 uint16_t entryPageOffset() const {
314 return _addressSpace.get16(
315 _addr + offsetof(unwind_info_regular_second_level_page_header,
316 entryPageOffset));
317 }
entryCount() const318 uint16_t entryCount() const {
319 return _addressSpace.get16(
320 _addr +
321 offsetof(unwind_info_regular_second_level_page_header, entryCount));
322 }
323
324 private:
325 A &_addressSpace;
326 typename A::pint_t _addr;
327 };
328
329 template <typename A> class UnwindSectionRegularArray {
330 public:
UnwindSectionRegularArray(A & addressSpace,typename A::pint_t addr)331 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
332 : _addressSpace(addressSpace), _addr(addr) {}
333
functionOffset(uint32_t index) const334 uint32_t functionOffset(uint32_t index) const {
335 return _addressSpace.get32(
336 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
337 functionOffset));
338 }
encoding(uint32_t index) const339 uint32_t encoding(uint32_t index) const {
340 return _addressSpace.get32(
341 _addr +
342 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
343 }
344
345 private:
346 A &_addressSpace;
347 typename A::pint_t _addr;
348 };
349
350 template <typename A> class UnwindSectionCompressedPageHeader {
351 public:
UnwindSectionCompressedPageHeader(A & addressSpace,typename A::pint_t addr)352 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
353 : _addressSpace(addressSpace), _addr(addr) {}
354
kind() const355 uint32_t kind() const {
356 return _addressSpace.get32(
357 _addr +
358 offsetof(unwind_info_compressed_second_level_page_header, kind));
359 }
entryPageOffset() const360 uint16_t entryPageOffset() const {
361 return _addressSpace.get16(
362 _addr + offsetof(unwind_info_compressed_second_level_page_header,
363 entryPageOffset));
364 }
entryCount() const365 uint16_t entryCount() const {
366 return _addressSpace.get16(
367 _addr +
368 offsetof(unwind_info_compressed_second_level_page_header, entryCount));
369 }
encodingsPageOffset() const370 uint16_t encodingsPageOffset() const {
371 return _addressSpace.get16(
372 _addr + offsetof(unwind_info_compressed_second_level_page_header,
373 encodingsPageOffset));
374 }
encodingsCount() const375 uint16_t encodingsCount() const {
376 return _addressSpace.get16(
377 _addr + offsetof(unwind_info_compressed_second_level_page_header,
378 encodingsCount));
379 }
380
381 private:
382 A &_addressSpace;
383 typename A::pint_t _addr;
384 };
385
386 template <typename A> class UnwindSectionCompressedArray {
387 public:
UnwindSectionCompressedArray(A & addressSpace,typename A::pint_t addr)388 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
389 : _addressSpace(addressSpace), _addr(addr) {}
390
functionOffset(uint32_t index) const391 uint32_t functionOffset(uint32_t index) const {
392 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
393 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
394 }
encodingIndex(uint32_t index) const395 uint16_t encodingIndex(uint32_t index) const {
396 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
397 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
398 }
399
400 private:
401 A &_addressSpace;
402 typename A::pint_t _addr;
403 };
404
405 template <typename A> class UnwindSectionLsdaArray {
406 public:
UnwindSectionLsdaArray(A & addressSpace,typename A::pint_t addr)407 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
408 : _addressSpace(addressSpace), _addr(addr) {}
409
functionOffset(uint32_t index) const410 uint32_t functionOffset(uint32_t index) const {
411 return _addressSpace.get32(
412 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
413 index, functionOffset));
414 }
lsdaOffset(uint32_t index) const415 uint32_t lsdaOffset(uint32_t index) const {
416 return _addressSpace.get32(
417 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
418 index, lsdaOffset));
419 }
420
421 private:
422 A &_addressSpace;
423 typename A::pint_t _addr;
424 };
425 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
426
427 class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
428 public:
429 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
430 // This avoids an unnecessary dependency to libc++abi.
operator delete(void *,size_t)431 void operator delete(void *, size_t) {}
432
~AbstractUnwindCursor()433 virtual ~AbstractUnwindCursor() {}
validReg(int)434 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
getReg(int)435 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
setReg(int,unw_word_t)436 virtual void setReg(int, unw_word_t) {
437 _LIBUNWIND_ABORT("setReg not implemented");
438 }
validFloatReg(int)439 virtual bool validFloatReg(int) {
440 _LIBUNWIND_ABORT("validFloatReg not implemented");
441 }
getFloatReg(int)442 virtual unw_fpreg_t getFloatReg(int) {
443 _LIBUNWIND_ABORT("getFloatReg not implemented");
444 }
setFloatReg(int,unw_fpreg_t)445 virtual void setFloatReg(int, unw_fpreg_t) {
446 _LIBUNWIND_ABORT("setFloatReg not implemented");
447 }
step(bool=false)448 virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); }
getInfo(unw_proc_info_t *)449 virtual void getInfo(unw_proc_info_t *) {
450 _LIBUNWIND_ABORT("getInfo not implemented");
451 }
jumpto()452 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
isSignalFrame()453 virtual bool isSignalFrame() {
454 _LIBUNWIND_ABORT("isSignalFrame not implemented");
455 }
getFunctionName(char *,size_t,unw_word_t *)456 virtual bool getFunctionName(char *, size_t, unw_word_t *) {
457 _LIBUNWIND_ABORT("getFunctionName not implemented");
458 }
setInfoBasedOnIPRegister(bool=false)459 virtual void setInfoBasedOnIPRegister(bool = false) {
460 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
461 }
getRegisterName(int)462 virtual const char *getRegisterName(int) {
463 _LIBUNWIND_ABORT("getRegisterName not implemented");
464 }
465 #ifdef __arm__
saveVFPAsX()466 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
467 #endif
468
469 #ifdef _AIX
getDataRelBase()470 virtual uintptr_t getDataRelBase() {
471 _LIBUNWIND_ABORT("getDataRelBase not implemented");
472 }
473 #endif
474
475 #if defined(_LIBUNWIND_USE_CET)
get_registers()476 virtual void *get_registers() {
477 _LIBUNWIND_ABORT("get_registers not implemented");
478 }
479 #endif
480 };
481
482 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
483
484 /// \c UnwindCursor contains all state (including all register values) during
485 /// an unwind. This is normally stack-allocated inside a unw_cursor_t.
486 template <typename A, typename R>
487 class UnwindCursor : public AbstractUnwindCursor {
488 typedef typename A::pint_t pint_t;
489 public:
490 UnwindCursor(unw_context_t *context, A &as);
491 UnwindCursor(CONTEXT *context, A &as);
492 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()493 virtual ~UnwindCursor() {}
494 virtual bool validReg(int);
495 virtual unw_word_t getReg(int);
496 virtual void setReg(int, unw_word_t);
497 virtual bool validFloatReg(int);
498 virtual unw_fpreg_t getFloatReg(int);
499 virtual void setFloatReg(int, unw_fpreg_t);
500 virtual int step(bool = false);
501 virtual void getInfo(unw_proc_info_t *);
502 virtual void jumpto();
503 virtual bool isSignalFrame();
504 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
505 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
506 virtual const char *getRegisterName(int num);
507 #ifdef __arm__
508 virtual void saveVFPAsX();
509 #endif
510
getDispatcherContext()511 DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
setDispatcherContext(DISPATCHER_CONTEXT * disp)512 void setDispatcherContext(DISPATCHER_CONTEXT *disp) {
513 _dispContext = *disp;
514 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
515 if (_dispContext.LanguageHandler) {
516 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
517 } else
518 _info.handler = 0;
519 }
520
521 // libunwind does not and should not depend on C++ library which means that we
522 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)523 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
524
525 private:
526
getLastPC() const527 pint_t getLastPC() const { return _dispContext.ControlPc; }
setLastPC(pint_t pc)528 void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)529 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
530 #ifdef __arm__
531 // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit.
532 pc &= ~1U;
533 #endif
534 // If pc points exactly at the end of the range, we might resolve the
535 // next function instead. Decrement pc by 1 to fit inside the current
536 // function.
537 pc -= 1;
538 _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
539 &_dispContext.ImageBase,
540 _dispContext.HistoryTable);
541 *base = _dispContext.ImageBase;
542 return _dispContext.FunctionEntry;
543 }
544 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()545 int stepWithSEHData() {
546 _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
547 _dispContext.ImageBase,
548 _dispContext.ControlPc,
549 _dispContext.FunctionEntry,
550 _dispContext.ContextRecord,
551 &_dispContext.HandlerData,
552 &_dispContext.EstablisherFrame,
553 NULL);
554 // Update some fields of the unwind info now, since we have them.
555 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
556 if (_dispContext.LanguageHandler) {
557 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
558 } else
559 _info.handler = 0;
560 return UNW_STEP_SUCCESS;
561 }
562
563 A &_addressSpace;
564 unw_proc_info_t _info;
565 DISPATCHER_CONTEXT _dispContext;
566 CONTEXT _msContext;
567 UNWIND_HISTORY_TABLE _histTable;
568 bool _unwindInfoMissing;
569 };
570
571
572 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)573 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
574 : _addressSpace(as), _unwindInfoMissing(false) {
575 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
576 "UnwindCursor<> does not fit in unw_cursor_t");
577 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
578 "UnwindCursor<> requires more alignment than unw_cursor_t");
579 memset(&_info, 0, sizeof(_info));
580 memset(&_histTable, 0, sizeof(_histTable));
581 memset(&_dispContext, 0, sizeof(_dispContext));
582 _dispContext.ContextRecord = &_msContext;
583 _dispContext.HistoryTable = &_histTable;
584 // Initialize MS context from ours.
585 R r(context);
586 RtlCaptureContext(&_msContext);
587 _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
588 #if defined(_LIBUNWIND_TARGET_X86_64)
589 _msContext.Rax = r.getRegister(UNW_X86_64_RAX);
590 _msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
591 _msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
592 _msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
593 _msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
594 _msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
595 _msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
596 _msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
597 _msContext.R8 = r.getRegister(UNW_X86_64_R8);
598 _msContext.R9 = r.getRegister(UNW_X86_64_R9);
599 _msContext.R10 = r.getRegister(UNW_X86_64_R10);
600 _msContext.R11 = r.getRegister(UNW_X86_64_R11);
601 _msContext.R12 = r.getRegister(UNW_X86_64_R12);
602 _msContext.R13 = r.getRegister(UNW_X86_64_R13);
603 _msContext.R14 = r.getRegister(UNW_X86_64_R14);
604 _msContext.R15 = r.getRegister(UNW_X86_64_R15);
605 _msContext.Rip = r.getRegister(UNW_REG_IP);
606 union {
607 v128 v;
608 M128A m;
609 } t;
610 t.v = r.getVectorRegister(UNW_X86_64_XMM0);
611 _msContext.Xmm0 = t.m;
612 t.v = r.getVectorRegister(UNW_X86_64_XMM1);
613 _msContext.Xmm1 = t.m;
614 t.v = r.getVectorRegister(UNW_X86_64_XMM2);
615 _msContext.Xmm2 = t.m;
616 t.v = r.getVectorRegister(UNW_X86_64_XMM3);
617 _msContext.Xmm3 = t.m;
618 t.v = r.getVectorRegister(UNW_X86_64_XMM4);
619 _msContext.Xmm4 = t.m;
620 t.v = r.getVectorRegister(UNW_X86_64_XMM5);
621 _msContext.Xmm5 = t.m;
622 t.v = r.getVectorRegister(UNW_X86_64_XMM6);
623 _msContext.Xmm6 = t.m;
624 t.v = r.getVectorRegister(UNW_X86_64_XMM7);
625 _msContext.Xmm7 = t.m;
626 t.v = r.getVectorRegister(UNW_X86_64_XMM8);
627 _msContext.Xmm8 = t.m;
628 t.v = r.getVectorRegister(UNW_X86_64_XMM9);
629 _msContext.Xmm9 = t.m;
630 t.v = r.getVectorRegister(UNW_X86_64_XMM10);
631 _msContext.Xmm10 = t.m;
632 t.v = r.getVectorRegister(UNW_X86_64_XMM11);
633 _msContext.Xmm11 = t.m;
634 t.v = r.getVectorRegister(UNW_X86_64_XMM12);
635 _msContext.Xmm12 = t.m;
636 t.v = r.getVectorRegister(UNW_X86_64_XMM13);
637 _msContext.Xmm13 = t.m;
638 t.v = r.getVectorRegister(UNW_X86_64_XMM14);
639 _msContext.Xmm14 = t.m;
640 t.v = r.getVectorRegister(UNW_X86_64_XMM15);
641 _msContext.Xmm15 = t.m;
642 #elif defined(_LIBUNWIND_TARGET_ARM)
643 _msContext.R0 = r.getRegister(UNW_ARM_R0);
644 _msContext.R1 = r.getRegister(UNW_ARM_R1);
645 _msContext.R2 = r.getRegister(UNW_ARM_R2);
646 _msContext.R3 = r.getRegister(UNW_ARM_R3);
647 _msContext.R4 = r.getRegister(UNW_ARM_R4);
648 _msContext.R5 = r.getRegister(UNW_ARM_R5);
649 _msContext.R6 = r.getRegister(UNW_ARM_R6);
650 _msContext.R7 = r.getRegister(UNW_ARM_R7);
651 _msContext.R8 = r.getRegister(UNW_ARM_R8);
652 _msContext.R9 = r.getRegister(UNW_ARM_R9);
653 _msContext.R10 = r.getRegister(UNW_ARM_R10);
654 _msContext.R11 = r.getRegister(UNW_ARM_R11);
655 _msContext.R12 = r.getRegister(UNW_ARM_R12);
656 _msContext.Sp = r.getRegister(UNW_ARM_SP);
657 _msContext.Lr = r.getRegister(UNW_ARM_LR);
658 _msContext.Pc = r.getRegister(UNW_ARM_IP);
659 for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
660 union {
661 uint64_t w;
662 double d;
663 } d;
664 d.d = r.getFloatRegister(i);
665 _msContext.D[i - UNW_ARM_D0] = d.w;
666 }
667 #elif defined(_LIBUNWIND_TARGET_AARCH64)
668 for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
669 _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
670 _msContext.Sp = r.getRegister(UNW_REG_SP);
671 _msContext.Pc = r.getRegister(UNW_REG_IP);
672 for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
673 _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
674 #endif
675 }
676
677 template <typename A, typename R>
UnwindCursor(CONTEXT * context,A & as)678 UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
679 : _addressSpace(as), _unwindInfoMissing(false) {
680 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
681 "UnwindCursor<> does not fit in unw_cursor_t");
682 memset(&_info, 0, sizeof(_info));
683 memset(&_histTable, 0, sizeof(_histTable));
684 memset(&_dispContext, 0, sizeof(_dispContext));
685 _dispContext.ContextRecord = &_msContext;
686 _dispContext.HistoryTable = &_histTable;
687 _msContext = *context;
688 }
689
690
691 template <typename A, typename R>
validReg(int regNum)692 bool UnwindCursor<A, R>::validReg(int regNum) {
693 if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
694 #if defined(_LIBUNWIND_TARGET_X86_64)
695 if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_RIP) return true;
696 #elif defined(_LIBUNWIND_TARGET_ARM)
697 if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
698 regNum == UNW_ARM_RA_AUTH_CODE)
699 return true;
700 #elif defined(_LIBUNWIND_TARGET_AARCH64)
701 if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
702 #endif
703 return false;
704 }
705
706 template <typename A, typename R>
getReg(int regNum)707 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
708 switch (regNum) {
709 #if defined(_LIBUNWIND_TARGET_X86_64)
710 case UNW_X86_64_RIP:
711 case UNW_REG_IP: return _msContext.Rip;
712 case UNW_X86_64_RAX: return _msContext.Rax;
713 case UNW_X86_64_RDX: return _msContext.Rdx;
714 case UNW_X86_64_RCX: return _msContext.Rcx;
715 case UNW_X86_64_RBX: return _msContext.Rbx;
716 case UNW_REG_SP:
717 case UNW_X86_64_RSP: return _msContext.Rsp;
718 case UNW_X86_64_RBP: return _msContext.Rbp;
719 case UNW_X86_64_RSI: return _msContext.Rsi;
720 case UNW_X86_64_RDI: return _msContext.Rdi;
721 case UNW_X86_64_R8: return _msContext.R8;
722 case UNW_X86_64_R9: return _msContext.R9;
723 case UNW_X86_64_R10: return _msContext.R10;
724 case UNW_X86_64_R11: return _msContext.R11;
725 case UNW_X86_64_R12: return _msContext.R12;
726 case UNW_X86_64_R13: return _msContext.R13;
727 case UNW_X86_64_R14: return _msContext.R14;
728 case UNW_X86_64_R15: return _msContext.R15;
729 #elif defined(_LIBUNWIND_TARGET_ARM)
730 case UNW_ARM_R0: return _msContext.R0;
731 case UNW_ARM_R1: return _msContext.R1;
732 case UNW_ARM_R2: return _msContext.R2;
733 case UNW_ARM_R3: return _msContext.R3;
734 case UNW_ARM_R4: return _msContext.R4;
735 case UNW_ARM_R5: return _msContext.R5;
736 case UNW_ARM_R6: return _msContext.R6;
737 case UNW_ARM_R7: return _msContext.R7;
738 case UNW_ARM_R8: return _msContext.R8;
739 case UNW_ARM_R9: return _msContext.R9;
740 case UNW_ARM_R10: return _msContext.R10;
741 case UNW_ARM_R11: return _msContext.R11;
742 case UNW_ARM_R12: return _msContext.R12;
743 case UNW_REG_SP:
744 case UNW_ARM_SP: return _msContext.Sp;
745 case UNW_ARM_LR: return _msContext.Lr;
746 case UNW_REG_IP:
747 case UNW_ARM_IP: return _msContext.Pc;
748 #elif defined(_LIBUNWIND_TARGET_AARCH64)
749 case UNW_REG_SP: return _msContext.Sp;
750 case UNW_REG_IP: return _msContext.Pc;
751 default: return _msContext.X[regNum - UNW_AARCH64_X0];
752 #endif
753 }
754 _LIBUNWIND_ABORT("unsupported register");
755 }
756
757 template <typename A, typename R>
setReg(int regNum,unw_word_t value)758 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
759 switch (regNum) {
760 #if defined(_LIBUNWIND_TARGET_X86_64)
761 case UNW_X86_64_RIP:
762 case UNW_REG_IP: _msContext.Rip = value; break;
763 case UNW_X86_64_RAX: _msContext.Rax = value; break;
764 case UNW_X86_64_RDX: _msContext.Rdx = value; break;
765 case UNW_X86_64_RCX: _msContext.Rcx = value; break;
766 case UNW_X86_64_RBX: _msContext.Rbx = value; break;
767 case UNW_REG_SP:
768 case UNW_X86_64_RSP: _msContext.Rsp = value; break;
769 case UNW_X86_64_RBP: _msContext.Rbp = value; break;
770 case UNW_X86_64_RSI: _msContext.Rsi = value; break;
771 case UNW_X86_64_RDI: _msContext.Rdi = value; break;
772 case UNW_X86_64_R8: _msContext.R8 = value; break;
773 case UNW_X86_64_R9: _msContext.R9 = value; break;
774 case UNW_X86_64_R10: _msContext.R10 = value; break;
775 case UNW_X86_64_R11: _msContext.R11 = value; break;
776 case UNW_X86_64_R12: _msContext.R12 = value; break;
777 case UNW_X86_64_R13: _msContext.R13 = value; break;
778 case UNW_X86_64_R14: _msContext.R14 = value; break;
779 case UNW_X86_64_R15: _msContext.R15 = value; break;
780 #elif defined(_LIBUNWIND_TARGET_ARM)
781 case UNW_ARM_R0: _msContext.R0 = value; break;
782 case UNW_ARM_R1: _msContext.R1 = value; break;
783 case UNW_ARM_R2: _msContext.R2 = value; break;
784 case UNW_ARM_R3: _msContext.R3 = value; break;
785 case UNW_ARM_R4: _msContext.R4 = value; break;
786 case UNW_ARM_R5: _msContext.R5 = value; break;
787 case UNW_ARM_R6: _msContext.R6 = value; break;
788 case UNW_ARM_R7: _msContext.R7 = value; break;
789 case UNW_ARM_R8: _msContext.R8 = value; break;
790 case UNW_ARM_R9: _msContext.R9 = value; break;
791 case UNW_ARM_R10: _msContext.R10 = value; break;
792 case UNW_ARM_R11: _msContext.R11 = value; break;
793 case UNW_ARM_R12: _msContext.R12 = value; break;
794 case UNW_REG_SP:
795 case UNW_ARM_SP: _msContext.Sp = value; break;
796 case UNW_ARM_LR: _msContext.Lr = value; break;
797 case UNW_REG_IP:
798 case UNW_ARM_IP: _msContext.Pc = value; break;
799 #elif defined(_LIBUNWIND_TARGET_AARCH64)
800 case UNW_REG_SP: _msContext.Sp = value; break;
801 case UNW_REG_IP: _msContext.Pc = value; break;
802 case UNW_AARCH64_X0:
803 case UNW_AARCH64_X1:
804 case UNW_AARCH64_X2:
805 case UNW_AARCH64_X3:
806 case UNW_AARCH64_X4:
807 case UNW_AARCH64_X5:
808 case UNW_AARCH64_X6:
809 case UNW_AARCH64_X7:
810 case UNW_AARCH64_X8:
811 case UNW_AARCH64_X9:
812 case UNW_AARCH64_X10:
813 case UNW_AARCH64_X11:
814 case UNW_AARCH64_X12:
815 case UNW_AARCH64_X13:
816 case UNW_AARCH64_X14:
817 case UNW_AARCH64_X15:
818 case UNW_AARCH64_X16:
819 case UNW_AARCH64_X17:
820 case UNW_AARCH64_X18:
821 case UNW_AARCH64_X19:
822 case UNW_AARCH64_X20:
823 case UNW_AARCH64_X21:
824 case UNW_AARCH64_X22:
825 case UNW_AARCH64_X23:
826 case UNW_AARCH64_X24:
827 case UNW_AARCH64_X25:
828 case UNW_AARCH64_X26:
829 case UNW_AARCH64_X27:
830 case UNW_AARCH64_X28:
831 case UNW_AARCH64_FP:
832 case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
833 #endif
834 default:
835 _LIBUNWIND_ABORT("unsupported register");
836 }
837 }
838
839 template <typename A, typename R>
validFloatReg(int regNum)840 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
841 #if defined(_LIBUNWIND_TARGET_ARM)
842 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
843 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
844 #elif defined(_LIBUNWIND_TARGET_AARCH64)
845 if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
846 #else
847 (void)regNum;
848 #endif
849 return false;
850 }
851
852 template <typename A, typename R>
getFloatReg(int regNum)853 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
854 #if defined(_LIBUNWIND_TARGET_ARM)
855 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
856 union {
857 uint32_t w;
858 float f;
859 } d;
860 d.w = _msContext.S[regNum - UNW_ARM_S0];
861 return d.f;
862 }
863 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
864 union {
865 uint64_t w;
866 double d;
867 } d;
868 d.w = _msContext.D[regNum - UNW_ARM_D0];
869 return d.d;
870 }
871 _LIBUNWIND_ABORT("unsupported float register");
872 #elif defined(_LIBUNWIND_TARGET_AARCH64)
873 return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
874 #else
875 (void)regNum;
876 _LIBUNWIND_ABORT("float registers unimplemented");
877 #endif
878 }
879
880 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)881 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
882 #if defined(_LIBUNWIND_TARGET_ARM)
883 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
884 union {
885 uint32_t w;
886 float f;
887 } d;
888 d.f = (float)value;
889 _msContext.S[regNum - UNW_ARM_S0] = d.w;
890 }
891 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
892 union {
893 uint64_t w;
894 double d;
895 } d;
896 d.d = value;
897 _msContext.D[regNum - UNW_ARM_D0] = d.w;
898 }
899 _LIBUNWIND_ABORT("unsupported float register");
900 #elif defined(_LIBUNWIND_TARGET_AARCH64)
901 _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
902 #else
903 (void)regNum;
904 (void)value;
905 _LIBUNWIND_ABORT("float registers unimplemented");
906 #endif
907 }
908
jumpto()909 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
910 RtlRestoreContext(&_msContext, nullptr);
911 }
912
913 #ifdef __arm__
saveVFPAsX()914 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
915 #endif
916
917 template <typename A, typename R>
getRegisterName(int regNum)918 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
919 return R::getRegisterName(regNum);
920 }
921
isSignalFrame()922 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
923 return false;
924 }
925
926 #else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
927
928 /// UnwindCursor contains all state (including all register values) during
929 /// an unwind. This is normally stack allocated inside a unw_cursor_t.
930 template <typename A, typename R>
931 class UnwindCursor : public AbstractUnwindCursor{
932 typedef typename A::pint_t pint_t;
933 public:
934 UnwindCursor(unw_context_t *context, A &as);
935 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()936 virtual ~UnwindCursor() {}
937 virtual bool validReg(int);
938 virtual unw_word_t getReg(int);
939 virtual void setReg(int, unw_word_t);
940 virtual bool validFloatReg(int);
941 virtual unw_fpreg_t getFloatReg(int);
942 virtual void setFloatReg(int, unw_fpreg_t);
943 virtual int step(bool stage2 = false);
944 virtual void getInfo(unw_proc_info_t *);
945 virtual void jumpto();
946 virtual bool isSignalFrame();
947 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
948 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
949 virtual const char *getRegisterName(int num);
950 #ifdef __arm__
951 virtual void saveVFPAsX();
952 #endif
953
954 #ifdef _AIX
955 virtual uintptr_t getDataRelBase();
956 #endif
957
958 #if defined(_LIBUNWIND_USE_CET)
get_registers()959 virtual void *get_registers() { return &_registers; }
960 #endif
961
962 // libunwind does not and should not depend on C++ library which means that we
963 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)964 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
965
966 private:
967
968 #if defined(_LIBUNWIND_ARM_EHABI)
969 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s);
970
stepWithEHABI()971 int stepWithEHABI() {
972 size_t len = 0;
973 size_t off = 0;
974 // FIXME: Calling decode_eht_entry() here is violating the libunwind
975 // abstraction layer.
976 const uint32_t *ehtp =
977 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
978 &off, &len);
979 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
980 _URC_CONTINUE_UNWIND)
981 return UNW_STEP_END;
982 return UNW_STEP_SUCCESS;
983 }
984 #endif
985
986 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
setInfoForSigReturn()987 bool setInfoForSigReturn() {
988 R dummy;
989 return setInfoForSigReturn(dummy);
990 }
stepThroughSigReturn()991 int stepThroughSigReturn() {
992 R dummy;
993 return stepThroughSigReturn(dummy);
994 }
995 bool isReadableAddr(const pint_t addr) const;
996 #if defined(_LIBUNWIND_TARGET_AARCH64)
997 bool setInfoForSigReturn(Registers_arm64 &);
998 int stepThroughSigReturn(Registers_arm64 &);
999 #endif
1000 #if defined(_LIBUNWIND_TARGET_RISCV)
1001 bool setInfoForSigReturn(Registers_riscv &);
1002 int stepThroughSigReturn(Registers_riscv &);
1003 #endif
1004 #if defined(_LIBUNWIND_TARGET_S390X)
1005 bool setInfoForSigReturn(Registers_s390x &);
1006 int stepThroughSigReturn(Registers_s390x &);
1007 #endif
setInfoForSigReturn(Registers &)1008 template <typename Registers> bool setInfoForSigReturn(Registers &) {
1009 return false;
1010 }
stepThroughSigReturn(Registers &)1011 template <typename Registers> int stepThroughSigReturn(Registers &) {
1012 return UNW_STEP_END;
1013 }
1014 #endif
1015
1016 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1017 bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1018 const typename CFI_Parser<A>::CIE_Info &cieInfo,
1019 pint_t pc, uintptr_t dso_base);
1020 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s,
1021 uint32_t fdeSectionOffsetHint=0);
stepWithDwarfFDE(bool stage2)1022 int stepWithDwarfFDE(bool stage2) {
1023 return DwarfInstructions<A, R>::stepWithDwarf(
1024 _addressSpace, (pint_t)this->getReg(UNW_REG_IP),
1025 (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2);
1026 }
1027 #endif
1028
1029 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1030 bool getInfoFromCompactEncodingSection(pint_t pc,
1031 const UnwindInfoSections §s);
stepWithCompactEncoding(bool stage2=false)1032 int stepWithCompactEncoding(bool stage2 = false) {
1033 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1034 if ( compactSaysUseDwarf() )
1035 return stepWithDwarfFDE(stage2);
1036 #endif
1037 R dummy;
1038 return stepWithCompactEncoding(dummy);
1039 }
1040
1041 #if defined(_LIBUNWIND_TARGET_X86_64)
stepWithCompactEncoding(Registers_x86_64 &)1042 int stepWithCompactEncoding(Registers_x86_64 &) {
1043 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
1044 _info.format, _info.start_ip, _addressSpace, _registers);
1045 }
1046 #endif
1047
1048 #if defined(_LIBUNWIND_TARGET_I386)
stepWithCompactEncoding(Registers_x86 &)1049 int stepWithCompactEncoding(Registers_x86 &) {
1050 return CompactUnwinder_x86<A>::stepWithCompactEncoding(
1051 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
1052 }
1053 #endif
1054
1055 #if defined(_LIBUNWIND_TARGET_PPC)
stepWithCompactEncoding(Registers_ppc &)1056 int stepWithCompactEncoding(Registers_ppc &) {
1057 return UNW_EINVAL;
1058 }
1059 #endif
1060
1061 #if defined(_LIBUNWIND_TARGET_PPC64)
stepWithCompactEncoding(Registers_ppc64 &)1062 int stepWithCompactEncoding(Registers_ppc64 &) {
1063 return UNW_EINVAL;
1064 }
1065 #endif
1066
1067
1068 #if defined(_LIBUNWIND_TARGET_AARCH64)
stepWithCompactEncoding(Registers_arm64 &)1069 int stepWithCompactEncoding(Registers_arm64 &) {
1070 return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
1071 _info.format, _info.start_ip, _addressSpace, _registers);
1072 }
1073 #endif
1074
1075 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
stepWithCompactEncoding(Registers_mips_o32 &)1076 int stepWithCompactEncoding(Registers_mips_o32 &) {
1077 return UNW_EINVAL;
1078 }
1079 #endif
1080
1081 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
stepWithCompactEncoding(Registers_mips_newabi &)1082 int stepWithCompactEncoding(Registers_mips_newabi &) {
1083 return UNW_EINVAL;
1084 }
1085 #endif
1086
1087 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
stepWithCompactEncoding(Registers_loongarch &)1088 int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; }
1089 #endif
1090
1091 #if defined(_LIBUNWIND_TARGET_SPARC)
stepWithCompactEncoding(Registers_sparc &)1092 int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
1093 #endif
1094
1095 #if defined(_LIBUNWIND_TARGET_SPARC64)
stepWithCompactEncoding(Registers_sparc64 &)1096 int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
1097 #endif
1098
1099 #if defined (_LIBUNWIND_TARGET_RISCV)
stepWithCompactEncoding(Registers_riscv &)1100 int stepWithCompactEncoding(Registers_riscv &) {
1101 return UNW_EINVAL;
1102 }
1103 #endif
1104
compactSaysUseDwarf(uint32_t * offset=NULL) const1105 bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
1106 R dummy;
1107 return compactSaysUseDwarf(dummy, offset);
1108 }
1109
1110 #if defined(_LIBUNWIND_TARGET_X86_64)
compactSaysUseDwarf(Registers_x86_64 &,uint32_t * offset) const1111 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
1112 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
1113 if (offset)
1114 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
1115 return true;
1116 }
1117 return false;
1118 }
1119 #endif
1120
1121 #if defined(_LIBUNWIND_TARGET_I386)
compactSaysUseDwarf(Registers_x86 &,uint32_t * offset) const1122 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
1123 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
1124 if (offset)
1125 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
1126 return true;
1127 }
1128 return false;
1129 }
1130 #endif
1131
1132 #if defined(_LIBUNWIND_TARGET_PPC)
compactSaysUseDwarf(Registers_ppc &,uint32_t *) const1133 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
1134 return true;
1135 }
1136 #endif
1137
1138 #if defined(_LIBUNWIND_TARGET_PPC64)
compactSaysUseDwarf(Registers_ppc64 &,uint32_t *) const1139 bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
1140 return true;
1141 }
1142 #endif
1143
1144 #if defined(_LIBUNWIND_TARGET_AARCH64)
compactSaysUseDwarf(Registers_arm64 &,uint32_t * offset) const1145 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
1146 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
1147 if (offset)
1148 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
1149 return true;
1150 }
1151 return false;
1152 }
1153 #endif
1154
1155 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
compactSaysUseDwarf(Registers_mips_o32 &,uint32_t *) const1156 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
1157 return true;
1158 }
1159 #endif
1160
1161 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
compactSaysUseDwarf(Registers_mips_newabi &,uint32_t *) const1162 bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
1163 return true;
1164 }
1165 #endif
1166
1167 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
compactSaysUseDwarf(Registers_loongarch &,uint32_t *) const1168 bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const {
1169 return true;
1170 }
1171 #endif
1172
1173 #if defined(_LIBUNWIND_TARGET_SPARC)
compactSaysUseDwarf(Registers_sparc &,uint32_t *) const1174 bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
1175 #endif
1176
1177 #if defined(_LIBUNWIND_TARGET_SPARC64)
compactSaysUseDwarf(Registers_sparc64 &,uint32_t *) const1178 bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
1179 return true;
1180 }
1181 #endif
1182
1183 #if defined (_LIBUNWIND_TARGET_RISCV)
compactSaysUseDwarf(Registers_riscv &,uint32_t *) const1184 bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
1185 return true;
1186 }
1187 #endif
1188
1189 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1190
1191 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
dwarfEncoding() const1192 compact_unwind_encoding_t dwarfEncoding() const {
1193 R dummy;
1194 return dwarfEncoding(dummy);
1195 }
1196
1197 #if defined(_LIBUNWIND_TARGET_X86_64)
dwarfEncoding(Registers_x86_64 &) const1198 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
1199 return UNWIND_X86_64_MODE_DWARF;
1200 }
1201 #endif
1202
1203 #if defined(_LIBUNWIND_TARGET_I386)
dwarfEncoding(Registers_x86 &) const1204 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
1205 return UNWIND_X86_MODE_DWARF;
1206 }
1207 #endif
1208
1209 #if defined(_LIBUNWIND_TARGET_PPC)
dwarfEncoding(Registers_ppc &) const1210 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
1211 return 0;
1212 }
1213 #endif
1214
1215 #if defined(_LIBUNWIND_TARGET_PPC64)
dwarfEncoding(Registers_ppc64 &) const1216 compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
1217 return 0;
1218 }
1219 #endif
1220
1221 #if defined(_LIBUNWIND_TARGET_AARCH64)
dwarfEncoding(Registers_arm64 &) const1222 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
1223 return UNWIND_ARM64_MODE_DWARF;
1224 }
1225 #endif
1226
1227 #if defined(_LIBUNWIND_TARGET_ARM)
dwarfEncoding(Registers_arm &) const1228 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
1229 return 0;
1230 }
1231 #endif
1232
1233 #if defined (_LIBUNWIND_TARGET_OR1K)
dwarfEncoding(Registers_or1k &) const1234 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
1235 return 0;
1236 }
1237 #endif
1238
1239 #if defined (_LIBUNWIND_TARGET_HEXAGON)
dwarfEncoding(Registers_hexagon &) const1240 compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
1241 return 0;
1242 }
1243 #endif
1244
1245 #if defined (_LIBUNWIND_TARGET_MIPS_O32)
dwarfEncoding(Registers_mips_o32 &) const1246 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
1247 return 0;
1248 }
1249 #endif
1250
1251 #if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
dwarfEncoding(Registers_mips_newabi &) const1252 compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
1253 return 0;
1254 }
1255 #endif
1256
1257 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
dwarfEncoding(Registers_loongarch &) const1258 compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const {
1259 return 0;
1260 }
1261 #endif
1262
1263 #if defined(_LIBUNWIND_TARGET_SPARC)
dwarfEncoding(Registers_sparc &) const1264 compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
1265 #endif
1266
1267 #if defined(_LIBUNWIND_TARGET_SPARC64)
dwarfEncoding(Registers_sparc64 &) const1268 compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
1269 return 0;
1270 }
1271 #endif
1272
1273 #if defined (_LIBUNWIND_TARGET_RISCV)
dwarfEncoding(Registers_riscv &) const1274 compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
1275 return 0;
1276 }
1277 #endif
1278
1279 #if defined (_LIBUNWIND_TARGET_S390X)
dwarfEncoding(Registers_s390x &) const1280 compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const {
1281 return 0;
1282 }
1283 #endif
1284
1285 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1286
1287 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1288 // For runtime environments using SEH unwind data without Windows runtime
1289 // support.
getLastPC() const1290 pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
setLastPC(pint_t pc)1291 void setLastPC(pint_t pc) { /* FIXME: Implement */ }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)1292 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
1293 /* FIXME: Implement */
1294 *base = 0;
1295 return nullptr;
1296 }
1297 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()1298 int stepWithSEHData() { /* FIXME: Implement */ return 0; }
1299 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1300
1301 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1302 bool getInfoFromTBTable(pint_t pc, R ®isters);
1303 int stepWithTBTable(pint_t pc, tbtable *TBTable, R ®isters,
1304 bool &isSignalFrame);
stepWithTBTableData()1305 int stepWithTBTableData() {
1306 return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
1307 reinterpret_cast<tbtable *>(_info.unwind_info),
1308 _registers, _isSignalFrame);
1309 }
1310 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1311
1312 A &_addressSpace;
1313 R _registers;
1314 unw_proc_info_t _info;
1315 bool _unwindInfoMissing;
1316 bool _isSignalFrame;
1317 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
1318 bool _isSigReturn = false;
1319 #endif
1320 };
1321
1322
1323 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)1324 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
1325 : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
1326 _isSignalFrame(false) {
1327 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
1328 "UnwindCursor<> does not fit in unw_cursor_t");
1329 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
1330 "UnwindCursor<> requires more alignment than unw_cursor_t");
1331 memset(&_info, 0, sizeof(_info));
1332 }
1333
1334 template <typename A, typename R>
UnwindCursor(A & as,void *)1335 UnwindCursor<A, R>::UnwindCursor(A &as, void *)
1336 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
1337 memset(&_info, 0, sizeof(_info));
1338 // FIXME
1339 // fill in _registers from thread arg
1340 }
1341
1342
1343 template <typename A, typename R>
validReg(int regNum)1344 bool UnwindCursor<A, R>::validReg(int regNum) {
1345 return _registers.validRegister(regNum);
1346 }
1347
1348 template <typename A, typename R>
getReg(int regNum)1349 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
1350 return _registers.getRegister(regNum);
1351 }
1352
1353 template <typename A, typename R>
setReg(int regNum,unw_word_t value)1354 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
1355 _registers.setRegister(regNum, (typename A::pint_t)value);
1356 }
1357
1358 template <typename A, typename R>
validFloatReg(int regNum)1359 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
1360 return _registers.validFloatRegister(regNum);
1361 }
1362
1363 template <typename A, typename R>
getFloatReg(int regNum)1364 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
1365 return _registers.getFloatRegister(regNum);
1366 }
1367
1368 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)1369 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
1370 _registers.setFloatRegister(regNum, value);
1371 }
1372
jumpto()1373 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
1374 _registers.jumpto();
1375 }
1376
1377 #ifdef __arm__
saveVFPAsX()1378 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
1379 _registers.saveVFPAsX();
1380 }
1381 #endif
1382
1383 #ifdef _AIX
1384 template <typename A, typename R>
getDataRelBase()1385 uintptr_t UnwindCursor<A, R>::getDataRelBase() {
1386 return reinterpret_cast<uintptr_t>(_info.extra);
1387 }
1388 #endif
1389
1390 template <typename A, typename R>
getRegisterName(int regNum)1391 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
1392 return _registers.getRegisterName(regNum);
1393 }
1394
isSignalFrame()1395 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
1396 return _isSignalFrame;
1397 }
1398
1399 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1400
1401 #if defined(_LIBUNWIND_ARM_EHABI)
1402 template<typename A>
1403 struct EHABISectionIterator {
1404 typedef EHABISectionIterator _Self;
1405
1406 typedef typename A::pint_t value_type;
1407 typedef typename A::pint_t* pointer;
1408 typedef typename A::pint_t& reference;
1409 typedef size_t size_type;
1410 typedef size_t difference_type;
1411
beginlibunwind::EHABISectionIterator1412 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
1413 return _Self(addressSpace, sects, 0);
1414 }
endlibunwind::EHABISectionIterator1415 static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
1416 return _Self(addressSpace, sects,
1417 sects.arm_section_length / sizeof(EHABIIndexEntry));
1418 }
1419
EHABISectionIteratorlibunwind::EHABISectionIterator1420 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
1421 : _i(i), _addressSpace(&addressSpace), _sects(§s) {}
1422
operator ++libunwind::EHABISectionIterator1423 _Self& operator++() { ++_i; return *this; }
operator +=libunwind::EHABISectionIterator1424 _Self& operator+=(size_t a) { _i += a; return *this; }
operator --libunwind::EHABISectionIterator1425 _Self& operator--() { assert(_i > 0); --_i; return *this; }
operator -=libunwind::EHABISectionIterator1426 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
1427
operator +libunwind::EHABISectionIterator1428 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
operator -libunwind::EHABISectionIterator1429 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
1430
operator -libunwind::EHABISectionIterator1431 size_t operator-(const _Self& other) const { return _i - other._i; }
1432
operator ==libunwind::EHABISectionIterator1433 bool operator==(const _Self& other) const {
1434 assert(_addressSpace == other._addressSpace);
1435 assert(_sects == other._sects);
1436 return _i == other._i;
1437 }
1438
operator !=libunwind::EHABISectionIterator1439 bool operator!=(const _Self& other) const {
1440 assert(_addressSpace == other._addressSpace);
1441 assert(_sects == other._sects);
1442 return _i != other._i;
1443 }
1444
operator *libunwind::EHABISectionIterator1445 typename A::pint_t operator*() const { return functionAddress(); }
1446
functionAddresslibunwind::EHABISectionIterator1447 typename A::pint_t functionAddress() const {
1448 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1449 EHABIIndexEntry, _i, functionOffset);
1450 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
1451 }
1452
dataAddresslibunwind::EHABISectionIterator1453 typename A::pint_t dataAddress() {
1454 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1455 EHABIIndexEntry, _i, data);
1456 return indexAddr;
1457 }
1458
1459 private:
1460 size_t _i;
1461 A* _addressSpace;
1462 const UnwindInfoSections* _sects;
1463 };
1464
1465 namespace {
1466
1467 template <typename A>
EHABISectionUpperBound(EHABISectionIterator<A> first,EHABISectionIterator<A> last,typename A::pint_t value)1468 EHABISectionIterator<A> EHABISectionUpperBound(
1469 EHABISectionIterator<A> first,
1470 EHABISectionIterator<A> last,
1471 typename A::pint_t value) {
1472 size_t len = last - first;
1473 while (len > 0) {
1474 size_t l2 = len / 2;
1475 EHABISectionIterator<A> m = first + l2;
1476 if (value < *m) {
1477 len = l2;
1478 } else {
1479 first = ++m;
1480 len -= l2 + 1;
1481 }
1482 }
1483 return first;
1484 }
1485
1486 }
1487
1488 template <typename A, typename R>
getInfoFromEHABISection(pint_t pc,const UnwindInfoSections & sects)1489 bool UnwindCursor<A, R>::getInfoFromEHABISection(
1490 pint_t pc,
1491 const UnwindInfoSections §s) {
1492 EHABISectionIterator<A> begin =
1493 EHABISectionIterator<A>::begin(_addressSpace, sects);
1494 EHABISectionIterator<A> end =
1495 EHABISectionIterator<A>::end(_addressSpace, sects);
1496 if (begin == end)
1497 return false;
1498
1499 EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
1500 if (itNextPC == begin)
1501 return false;
1502 EHABISectionIterator<A> itThisPC = itNextPC - 1;
1503
1504 pint_t thisPC = itThisPC.functionAddress();
1505 // If an exception is thrown from a function, corresponding to the last entry
1506 // in the table, we don't really know the function extent and have to choose a
1507 // value for nextPC. Choosing max() will allow the range check during trace to
1508 // succeed.
1509 pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
1510 pint_t indexDataAddr = itThisPC.dataAddress();
1511
1512 if (indexDataAddr == 0)
1513 return false;
1514
1515 uint32_t indexData = _addressSpace.get32(indexDataAddr);
1516 if (indexData == UNW_EXIDX_CANTUNWIND)
1517 return false;
1518
1519 // If the high bit is set, the exception handling table entry is inline inside
1520 // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
1521 // the table points at an offset in the exception handling table (section 5
1522 // EHABI).
1523 pint_t exceptionTableAddr;
1524 uint32_t exceptionTableData;
1525 bool isSingleWordEHT;
1526 if (indexData & 0x80000000) {
1527 exceptionTableAddr = indexDataAddr;
1528 // TODO(ajwong): Should this data be 0?
1529 exceptionTableData = indexData;
1530 isSingleWordEHT = true;
1531 } else {
1532 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
1533 exceptionTableData = _addressSpace.get32(exceptionTableAddr);
1534 isSingleWordEHT = false;
1535 }
1536
1537 // Now we know the 3 things:
1538 // exceptionTableAddr -- exception handler table entry.
1539 // exceptionTableData -- the data inside the first word of the eht entry.
1540 // isSingleWordEHT -- whether the entry is in the index.
1541 unw_word_t personalityRoutine = 0xbadf00d;
1542 bool scope32 = false;
1543 uintptr_t lsda;
1544
1545 // If the high bit in the exception handling table entry is set, the entry is
1546 // in compact form (section 6.3 EHABI).
1547 if (exceptionTableData & 0x80000000) {
1548 // Grab the index of the personality routine from the compact form.
1549 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
1550 uint32_t extraWords = 0;
1551 switch (choice) {
1552 case 0:
1553 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
1554 extraWords = 0;
1555 scope32 = false;
1556 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
1557 break;
1558 case 1:
1559 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
1560 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1561 scope32 = false;
1562 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1563 break;
1564 case 2:
1565 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
1566 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1567 scope32 = true;
1568 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1569 break;
1570 default:
1571 _LIBUNWIND_ABORT("unknown personality routine");
1572 return false;
1573 }
1574
1575 if (isSingleWordEHT) {
1576 if (extraWords != 0) {
1577 _LIBUNWIND_ABORT("index inlined table detected but pr function "
1578 "requires extra words");
1579 return false;
1580 }
1581 }
1582 } else {
1583 pint_t personalityAddr =
1584 exceptionTableAddr + signExtendPrel31(exceptionTableData);
1585 personalityRoutine = personalityAddr;
1586
1587 // ARM EHABI # 6.2, # 9.2
1588 //
1589 // +---- ehtp
1590 // v
1591 // +--------------------------------------+
1592 // | +--------+--------+--------+-------+ |
1593 // | |0| prel31 to personalityRoutine | |
1594 // | +--------+--------+--------+-------+ |
1595 // | | N | unwind opcodes | | <-- UnwindData
1596 // | +--------+--------+--------+-------+ |
1597 // | | Word 2 unwind opcodes | |
1598 // | +--------+--------+--------+-------+ |
1599 // | ... |
1600 // | +--------+--------+--------+-------+ |
1601 // | | Word N unwind opcodes | |
1602 // | +--------+--------+--------+-------+ |
1603 // | | LSDA | | <-- lsda
1604 // | | ... | |
1605 // | +--------+--------+--------+-------+ |
1606 // +--------------------------------------+
1607
1608 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
1609 uint32_t FirstDataWord = *UnwindData;
1610 size_t N = ((FirstDataWord >> 24) & 0xff);
1611 size_t NDataWords = N + 1;
1612 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
1613 }
1614
1615 _info.start_ip = thisPC;
1616 _info.end_ip = nextPC;
1617 _info.handler = personalityRoutine;
1618 _info.unwind_info = exceptionTableAddr;
1619 _info.lsda = lsda;
1620 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
1621 _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum?
1622
1623 return true;
1624 }
1625 #endif
1626
1627 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1628 template <typename A, typename R>
getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info & fdeInfo,const typename CFI_Parser<A>::CIE_Info & cieInfo,pint_t pc,uintptr_t dso_base)1629 bool UnwindCursor<A, R>::getInfoFromFdeCie(
1630 const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1631 const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc,
1632 uintptr_t dso_base) {
1633 typename CFI_Parser<A>::PrologInfo prolog;
1634 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
1635 R::getArch(), &prolog)) {
1636 // Save off parsed FDE info
1637 _info.start_ip = fdeInfo.pcStart;
1638 _info.end_ip = fdeInfo.pcEnd;
1639 _info.lsda = fdeInfo.lsda;
1640 _info.handler = cieInfo.personality;
1641 // Some frameless functions need SP altered when resuming in function, so
1642 // propagate spExtraArgSize.
1643 _info.gp = prolog.spExtraArgSize;
1644 _info.flags = 0;
1645 _info.format = dwarfEncoding();
1646 _info.unwind_info = fdeInfo.fdeStart;
1647 _info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength);
1648 _info.extra = static_cast<unw_word_t>(dso_base);
1649 return true;
1650 }
1651 return false;
1652 }
1653
1654 template <typename A, typename R>
getInfoFromDwarfSection(pint_t pc,const UnwindInfoSections & sects,uint32_t fdeSectionOffsetHint)1655 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
1656 const UnwindInfoSections §s,
1657 uint32_t fdeSectionOffsetHint) {
1658 typename CFI_Parser<A>::FDE_Info fdeInfo;
1659 typename CFI_Parser<A>::CIE_Info cieInfo;
1660 bool foundFDE = false;
1661 bool foundInCache = false;
1662 // If compact encoding table gave offset into dwarf section, go directly there
1663 if (fdeSectionOffsetHint != 0) {
1664 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1665 sects.dwarf_section_length,
1666 sects.dwarf_section + fdeSectionOffsetHint,
1667 &fdeInfo, &cieInfo);
1668 }
1669 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1670 if (!foundFDE && (sects.dwarf_index_section != 0)) {
1671 foundFDE = EHHeaderParser<A>::findFDE(
1672 _addressSpace, pc, sects.dwarf_index_section,
1673 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
1674 }
1675 #endif
1676 if (!foundFDE) {
1677 // otherwise, search cache of previously found FDEs.
1678 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
1679 if (cachedFDE != 0) {
1680 foundFDE =
1681 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1682 sects.dwarf_section_length,
1683 cachedFDE, &fdeInfo, &cieInfo);
1684 foundInCache = foundFDE;
1685 }
1686 }
1687 if (!foundFDE) {
1688 // Still not found, do full scan of __eh_frame section.
1689 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1690 sects.dwarf_section_length, 0,
1691 &fdeInfo, &cieInfo);
1692 }
1693 if (foundFDE) {
1694 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) {
1695 // Add to cache (to make next lookup faster) if we had no hint
1696 // and there was no index.
1697 if (!foundInCache && (fdeSectionOffsetHint == 0)) {
1698 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1699 if (sects.dwarf_index_section == 0)
1700 #endif
1701 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
1702 fdeInfo.fdeStart);
1703 }
1704 return true;
1705 }
1706 }
1707 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
1708 return false;
1709 }
1710 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1711
1712
1713 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1714 template <typename A, typename R>
getInfoFromCompactEncodingSection(pint_t pc,const UnwindInfoSections & sects)1715 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
1716 const UnwindInfoSections §s) {
1717 const bool log = false;
1718 if (log)
1719 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
1720 (uint64_t)pc, (uint64_t)sects.dso_base);
1721
1722 const UnwindSectionHeader<A> sectionHeader(_addressSpace,
1723 sects.compact_unwind_section);
1724 if (sectionHeader.version() != UNWIND_SECTION_VERSION)
1725 return false;
1726
1727 // do a binary search of top level index to find page with unwind info
1728 pint_t targetFunctionOffset = pc - sects.dso_base;
1729 const UnwindSectionIndexArray<A> topIndex(_addressSpace,
1730 sects.compact_unwind_section
1731 + sectionHeader.indexSectionOffset());
1732 uint32_t low = 0;
1733 uint32_t high = sectionHeader.indexCount();
1734 uint32_t last = high - 1;
1735 while (low < high) {
1736 uint32_t mid = (low + high) / 2;
1737 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
1738 //mid, low, high, topIndex.functionOffset(mid));
1739 if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
1740 if ((mid == last) ||
1741 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
1742 low = mid;
1743 break;
1744 } else {
1745 low = mid + 1;
1746 }
1747 } else {
1748 high = mid;
1749 }
1750 }
1751 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
1752 const uint32_t firstLevelNextPageFunctionOffset =
1753 topIndex.functionOffset(low + 1);
1754 const pint_t secondLevelAddr =
1755 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
1756 const pint_t lsdaArrayStartAddr =
1757 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
1758 const pint_t lsdaArrayEndAddr =
1759 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
1760 if (log)
1761 fprintf(stderr, "\tfirst level search for result index=%d "
1762 "to secondLevelAddr=0x%llX\n",
1763 low, (uint64_t) secondLevelAddr);
1764 // do a binary search of second level page index
1765 uint32_t encoding = 0;
1766 pint_t funcStart = 0;
1767 pint_t funcEnd = 0;
1768 pint_t lsda = 0;
1769 pint_t personality = 0;
1770 uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
1771 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
1772 // regular page
1773 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
1774 secondLevelAddr);
1775 UnwindSectionRegularArray<A> pageIndex(
1776 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1777 // binary search looks for entry with e where index[e].offset <= pc <
1778 // index[e+1].offset
1779 if (log)
1780 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
1781 "regular page starting at secondLevelAddr=0x%llX\n",
1782 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
1783 low = 0;
1784 high = pageHeader.entryCount();
1785 while (low < high) {
1786 uint32_t mid = (low + high) / 2;
1787 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
1788 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
1789 // at end of table
1790 low = mid;
1791 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1792 break;
1793 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
1794 // next is too big, so we found it
1795 low = mid;
1796 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
1797 break;
1798 } else {
1799 low = mid + 1;
1800 }
1801 } else {
1802 high = mid;
1803 }
1804 }
1805 encoding = pageIndex.encoding(low);
1806 funcStart = pageIndex.functionOffset(low) + sects.dso_base;
1807 if (pc < funcStart) {
1808 if (log)
1809 fprintf(
1810 stderr,
1811 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1812 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1813 return false;
1814 }
1815 if (pc > funcEnd) {
1816 if (log)
1817 fprintf(
1818 stderr,
1819 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1820 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1821 return false;
1822 }
1823 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
1824 // compressed page
1825 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
1826 secondLevelAddr);
1827 UnwindSectionCompressedArray<A> pageIndex(
1828 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1829 const uint32_t targetFunctionPageOffset =
1830 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
1831 // binary search looks for entry with e where index[e].offset <= pc <
1832 // index[e+1].offset
1833 if (log)
1834 fprintf(stderr, "\tbinary search of compressed page starting at "
1835 "secondLevelAddr=0x%llX\n",
1836 (uint64_t) secondLevelAddr);
1837 low = 0;
1838 last = pageHeader.entryCount() - 1;
1839 high = pageHeader.entryCount();
1840 while (low < high) {
1841 uint32_t mid = (low + high) / 2;
1842 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
1843 if ((mid == last) ||
1844 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
1845 low = mid;
1846 break;
1847 } else {
1848 low = mid + 1;
1849 }
1850 } else {
1851 high = mid;
1852 }
1853 }
1854 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
1855 + sects.dso_base;
1856 if (low < last)
1857 funcEnd =
1858 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
1859 + sects.dso_base;
1860 else
1861 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1862 if (pc < funcStart) {
1863 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1864 "not in second level compressed unwind table. "
1865 "funcStart=0x%llX",
1866 (uint64_t) pc, (uint64_t) funcStart);
1867 return false;
1868 }
1869 if (pc > funcEnd) {
1870 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1871 "not in second level compressed unwind table. "
1872 "funcEnd=0x%llX",
1873 (uint64_t) pc, (uint64_t) funcEnd);
1874 return false;
1875 }
1876 uint16_t encodingIndex = pageIndex.encodingIndex(low);
1877 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
1878 // encoding is in common table in section header
1879 encoding = _addressSpace.get32(
1880 sects.compact_unwind_section +
1881 sectionHeader.commonEncodingsArraySectionOffset() +
1882 encodingIndex * sizeof(uint32_t));
1883 } else {
1884 // encoding is in page specific table
1885 uint16_t pageEncodingIndex =
1886 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
1887 encoding = _addressSpace.get32(secondLevelAddr +
1888 pageHeader.encodingsPageOffset() +
1889 pageEncodingIndex * sizeof(uint32_t));
1890 }
1891 } else {
1892 _LIBUNWIND_DEBUG_LOG(
1893 "malformed __unwind_info at 0x%0llX bad second level page",
1894 (uint64_t)sects.compact_unwind_section);
1895 return false;
1896 }
1897
1898 // look up LSDA, if encoding says function has one
1899 if (encoding & UNWIND_HAS_LSDA) {
1900 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
1901 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
1902 low = 0;
1903 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
1904 sizeof(unwind_info_section_header_lsda_index_entry);
1905 // binary search looks for entry with exact match for functionOffset
1906 if (log)
1907 fprintf(stderr,
1908 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
1909 funcStartOffset);
1910 while (low < high) {
1911 uint32_t mid = (low + high) / 2;
1912 if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
1913 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
1914 break;
1915 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
1916 low = mid + 1;
1917 } else {
1918 high = mid;
1919 }
1920 }
1921 if (lsda == 0) {
1922 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
1923 "pc=0x%0llX, but lsda table has no entry",
1924 encoding, (uint64_t) pc);
1925 return false;
1926 }
1927 }
1928
1929 // extract personality routine, if encoding says function has one
1930 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
1931 (__builtin_ctz(UNWIND_PERSONALITY_MASK));
1932 if (personalityIndex != 0) {
1933 --personalityIndex; // change 1-based to zero-based index
1934 if (personalityIndex >= sectionHeader.personalityArrayCount()) {
1935 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
1936 "but personality table has only %d entries",
1937 encoding, personalityIndex,
1938 sectionHeader.personalityArrayCount());
1939 return false;
1940 }
1941 int32_t personalityDelta = (int32_t)_addressSpace.get32(
1942 sects.compact_unwind_section +
1943 sectionHeader.personalityArraySectionOffset() +
1944 personalityIndex * sizeof(uint32_t));
1945 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
1946 personality = _addressSpace.getP(personalityPointer);
1947 if (log)
1948 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1949 "personalityDelta=0x%08X, personality=0x%08llX\n",
1950 (uint64_t) pc, personalityDelta, (uint64_t) personality);
1951 }
1952
1953 if (log)
1954 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1955 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
1956 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
1957 _info.start_ip = funcStart;
1958 _info.end_ip = funcEnd;
1959 _info.lsda = lsda;
1960 _info.handler = personality;
1961 _info.gp = 0;
1962 _info.flags = 0;
1963 _info.format = encoding;
1964 _info.unwind_info = 0;
1965 _info.unwind_info_size = 0;
1966 _info.extra = sects.dso_base;
1967 return true;
1968 }
1969 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1970
1971
1972 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1973 template <typename A, typename R>
getInfoFromSEH(pint_t pc)1974 bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
1975 pint_t base;
1976 RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
1977 if (!unwindEntry) {
1978 _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
1979 return false;
1980 }
1981 _info.gp = 0;
1982 _info.flags = 0;
1983 _info.format = 0;
1984 _info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
1985 _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
1986 _info.extra = base;
1987 _info.start_ip = base + unwindEntry->BeginAddress;
1988 #ifdef _LIBUNWIND_TARGET_X86_64
1989 _info.end_ip = base + unwindEntry->EndAddress;
1990 // Only fill in the handler and LSDA if they're stale.
1991 if (pc != getLastPC()) {
1992 UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
1993 if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
1994 // The personality is given in the UNWIND_INFO itself. The LSDA immediately
1995 // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
1996 // these structures.)
1997 // N.B. UNWIND_INFO structs are DWORD-aligned.
1998 uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
1999 const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
2000 _info.lsda = reinterpret_cast<unw_word_t>(handler+1);
2001 _dispContext.HandlerData = reinterpret_cast<void *>(_info.lsda);
2002 _dispContext.LanguageHandler =
2003 reinterpret_cast<EXCEPTION_ROUTINE *>(base + *handler);
2004 if (*handler) {
2005 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2006 } else
2007 _info.handler = 0;
2008 } else {
2009 _info.lsda = 0;
2010 _info.handler = 0;
2011 }
2012 }
2013 #endif
2014 setLastPC(pc);
2015 return true;
2016 }
2017 #endif
2018
2019 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2020 // Masks for traceback table field xtbtable.
2021 enum xTBTableMask : uint8_t {
2022 reservedBit = 0x02, // The traceback table was incorrectly generated if set
2023 // (see comments in function getInfoFromTBTable().
2024 ehInfoBit = 0x08 // Exception handling info is present if set
2025 };
2026
2027 enum frameType : unw_word_t {
2028 frameWithXLEHStateTable = 0,
2029 frameWithEHInfo = 1
2030 };
2031
2032 extern "C" {
2033 typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
2034 uint64_t,
2035 _Unwind_Exception *,
2036 struct _Unwind_Context *);
2037 __attribute__((__weak__)) __xlcxx_personality_v0_t __xlcxx_personality_v0;
2038 }
2039
2040 static __xlcxx_personality_v0_t *xlcPersonalityV0;
2041 static RWMutex xlcPersonalityV0InitLock;
2042
2043 template <typename A, typename R>
getInfoFromTBTable(pint_t pc,R & registers)2044 bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R ®isters) {
2045 uint32_t *p = reinterpret_cast<uint32_t *>(pc);
2046
2047 // Keep looking forward until a word of 0 is found. The traceback
2048 // table starts at the following word.
2049 while (*p)
2050 ++p;
2051 tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
2052
2053 if (_LIBUNWIND_TRACING_UNWINDING) {
2054 char functionBuf[512];
2055 const char *functionName = functionBuf;
2056 unw_word_t offset;
2057 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2058 functionName = ".anonymous.";
2059 }
2060 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2061 __func__, functionName,
2062 reinterpret_cast<void *>(TBTable));
2063 }
2064
2065 // If the traceback table does not contain necessary info, bypass this frame.
2066 if (!TBTable->tb.has_tboff)
2067 return false;
2068
2069 // Structure tbtable_ext contains important data we are looking for.
2070 p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2071
2072 // Skip field parminfo if it exists.
2073 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2074 ++p;
2075
2076 // p now points to tb_offset, the offset from start of function to TB table.
2077 unw_word_t start_ip =
2078 reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
2079 unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
2080 ++p;
2081
2082 _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
2083 reinterpret_cast<void *>(start_ip),
2084 reinterpret_cast<void *>(end_ip));
2085
2086 // Skip field hand_mask if it exists.
2087 if (TBTable->tb.int_hndl)
2088 ++p;
2089
2090 unw_word_t lsda = 0;
2091 unw_word_t handler = 0;
2092 unw_word_t flags = frameType::frameWithXLEHStateTable;
2093
2094 if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
2095 // State table info is available. The ctl_info field indicates the
2096 // number of CTL anchors. There should be only one entry for the C++
2097 // state table.
2098 assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
2099 ++p;
2100 // p points to the offset of the state table into the stack.
2101 pint_t stateTableOffset = *p++;
2102
2103 int framePointerReg;
2104
2105 // Skip fields name_len and name if exist.
2106 if (TBTable->tb.name_present) {
2107 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
2108 p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
2109 sizeof(uint16_t));
2110 }
2111
2112 if (TBTable->tb.uses_alloca)
2113 framePointerReg = *(reinterpret_cast<char *>(p));
2114 else
2115 framePointerReg = 1; // default frame pointer == SP
2116
2117 _LIBUNWIND_TRACE_UNWINDING(
2118 "framePointerReg=%d, framePointer=%p, "
2119 "stateTableOffset=%#lx\n",
2120 framePointerReg,
2121 reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
2122 stateTableOffset);
2123 lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
2124
2125 // Since the traceback table generated by the legacy XLC++ does not
2126 // provide the location of the personality for the state table,
2127 // function __xlcxx_personality_v0(), which is the personality for the state
2128 // table and is exported from libc++abi, is directly assigned as the
2129 // handler here. When a legacy XLC++ frame is encountered, the symbol
2130 // is resolved dynamically using dlopen() to avoid hard dependency from
2131 // libunwind on libc++abi.
2132
2133 // Resolve the function pointer to the state table personality if it has
2134 // not already.
2135 if (xlcPersonalityV0 == NULL) {
2136 xlcPersonalityV0InitLock.lock();
2137 if (xlcPersonalityV0 == NULL) {
2138 // If libc++abi is statically linked in, symbol __xlcxx_personality_v0
2139 // has been resolved at the link time.
2140 xlcPersonalityV0 = &__xlcxx_personality_v0;
2141 if (xlcPersonalityV0 == NULL) {
2142 // libc++abi is dynamically linked. Resolve __xlcxx_personality_v0
2143 // using dlopen().
2144 const char libcxxabi[] = "libc++abi.a(libc++abi.so.1)";
2145 void *libHandle;
2146 // The AIX dlopen() sets errno to 0 when it is successful, which
2147 // clobbers the value of errno from the user code. This is an AIX
2148 // bug because according to POSIX it should not set errno to 0. To
2149 // workaround before AIX fixes the bug, errno is saved and restored.
2150 int saveErrno = errno;
2151 libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
2152 if (libHandle == NULL) {
2153 _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n",
2154 errno);
2155 assert(0 && "dlopen() failed");
2156 }
2157 xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
2158 dlsym(libHandle, "__xlcxx_personality_v0"));
2159 if (xlcPersonalityV0 == NULL) {
2160 _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
2161 assert(0 && "dlsym() failed");
2162 }
2163 dlclose(libHandle);
2164 errno = saveErrno;
2165 }
2166 }
2167 xlcPersonalityV0InitLock.unlock();
2168 }
2169 handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
2170 _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
2171 reinterpret_cast<void *>(lsda),
2172 reinterpret_cast<void *>(handler));
2173 } else if (TBTable->tb.longtbtable) {
2174 // This frame has the traceback table extension. Possible cases are
2175 // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
2176 // is not EH aware; or, 3) a frame of other languages. We need to figure out
2177 // if the traceback table extension contains the 'eh_info' structure.
2178 //
2179 // We also need to deal with the complexity arising from some XL compiler
2180 // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
2181 // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
2182 // versa. For frames of code generated by those compilers, the 'longtbtable'
2183 // bit may be set but there isn't really a traceback table extension.
2184 //
2185 // In </usr/include/sys/debug.h>, there is the following definition of
2186 // 'struct tbtable_ext'. It is not really a structure but a dummy to
2187 // collect the description of optional parts of the traceback table.
2188 //
2189 // struct tbtable_ext {
2190 // ...
2191 // char alloca_reg; /* Register for alloca automatic storage */
2192 // struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
2193 // unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
2194 // };
2195 //
2196 // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
2197 // following 'alloca_reg' can be treated either as 'struct vec_ext' or
2198 // 'unsigned char xtbtable'. 'xtbtable' bits are defined in
2199 // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
2200 // unused and should not be set. 'struct vec_ext' is defined in
2201 // </usr/include/sys/debug.h> as follows:
2202 //
2203 // struct vec_ext {
2204 // unsigned vr_saved:6; /* Number of non-volatile vector regs saved
2205 // */
2206 // /* first register saved is assumed to be */
2207 // /* 32 - vr_saved */
2208 // unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */
2209 // unsigned has_varargs:1;
2210 // ...
2211 // };
2212 //
2213 // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
2214 // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
2215 // we checks if the 7th bit is set or not because 'xtbtable' should
2216 // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
2217 // in the future to make sure the mitigation works. This mitigation
2218 // is not 100% bullet proof because 'struct vec_ext' may not always have
2219 // 'saves_vrsave' bit set.
2220 //
2221 // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
2222 // checking the 7th bit.
2223
2224 // p points to field name len.
2225 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2226
2227 // Skip fields name_len and name if they exist.
2228 if (TBTable->tb.name_present) {
2229 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2230 charPtr = charPtr + name_len + sizeof(uint16_t);
2231 }
2232
2233 // Skip field alloc_reg if it exists.
2234 if (TBTable->tb.uses_alloca)
2235 ++charPtr;
2236
2237 // Check traceback table bit has_vec. Skip struct vec_ext if it exists.
2238 if (TBTable->tb.has_vec)
2239 // Note struct vec_ext does exist at this point because whether the
2240 // ordering of longtbtable and has_vec bits is correct or not, both
2241 // are set.
2242 charPtr += sizeof(struct vec_ext);
2243
2244 // charPtr points to field 'xtbtable'. Check if the EH info is available.
2245 // Also check if the reserved bit of the extended traceback table field
2246 // 'xtbtable' is set. If it is, the traceback table was incorrectly
2247 // generated by an XL compiler that uses the wrong ordering of 'longtbtable'
2248 // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
2249 // frame.
2250 if ((*charPtr & xTBTableMask::ehInfoBit) &&
2251 !(*charPtr & xTBTableMask::reservedBit)) {
2252 // Mark this frame has the new EH info.
2253 flags = frameType::frameWithEHInfo;
2254
2255 // eh_info is available.
2256 charPtr++;
2257 // The pointer is 4-byte aligned.
2258 if (reinterpret_cast<uintptr_t>(charPtr) % 4)
2259 charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
2260 uintptr_t *ehInfo =
2261 reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
2262 registers.getRegister(2) +
2263 *(reinterpret_cast<uintptr_t *>(charPtr)))));
2264
2265 // ehInfo points to structure en_info. The first member is version.
2266 // Only version 0 is currently supported.
2267 assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
2268 "libunwind: ehInfo version other than 0 is not supported");
2269
2270 // Increment ehInfo to point to member lsda.
2271 ++ehInfo;
2272 lsda = *ehInfo++;
2273
2274 // enInfo now points to member personality.
2275 handler = *ehInfo;
2276
2277 _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
2278 lsda, handler);
2279 }
2280 }
2281
2282 _info.start_ip = start_ip;
2283 _info.end_ip = end_ip;
2284 _info.lsda = lsda;
2285 _info.handler = handler;
2286 _info.gp = 0;
2287 _info.flags = flags;
2288 _info.format = 0;
2289 _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
2290 _info.unwind_info_size = 0;
2291 _info.extra = registers.getRegister(2);
2292
2293 return true;
2294 }
2295
2296 // Step back up the stack following the frame back link.
2297 template <typename A, typename R>
stepWithTBTable(pint_t pc,tbtable * TBTable,R & registers,bool & isSignalFrame)2298 int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
2299 R ®isters, bool &isSignalFrame) {
2300 if (_LIBUNWIND_TRACING_UNWINDING) {
2301 char functionBuf[512];
2302 const char *functionName = functionBuf;
2303 unw_word_t offset;
2304 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2305 functionName = ".anonymous.";
2306 }
2307 _LIBUNWIND_TRACE_UNWINDING(
2308 "%s: Look up traceback table of func=%s at %p, pc=%p, "
2309 "SP=%p, saves_lr=%d, stores_bc=%d",
2310 __func__, functionName, reinterpret_cast<void *>(TBTable),
2311 reinterpret_cast<void *>(pc),
2312 reinterpret_cast<void *>(registers.getSP()), TBTable->tb.saves_lr,
2313 TBTable->tb.stores_bc);
2314 }
2315
2316 #if defined(__powerpc64__)
2317 // Instruction to reload TOC register "ld r2,40(r1)"
2318 const uint32_t loadTOCRegInst = 0xe8410028;
2319 const int32_t unwPPCF0Index = UNW_PPC64_F0;
2320 const int32_t unwPPCV0Index = UNW_PPC64_V0;
2321 #else
2322 // Instruction to reload TOC register "lwz r2,20(r1)"
2323 const uint32_t loadTOCRegInst = 0x80410014;
2324 const int32_t unwPPCF0Index = UNW_PPC_F0;
2325 const int32_t unwPPCV0Index = UNW_PPC_V0;
2326 #endif
2327
2328 // lastStack points to the stack frame of the next routine up.
2329 pint_t curStack = static_cast<pint_t>(registers.getSP());
2330 pint_t lastStack = *reinterpret_cast<pint_t *>(curStack);
2331
2332 if (lastStack == 0)
2333 return UNW_STEP_END;
2334
2335 R newRegisters = registers;
2336
2337 // If backchain is not stored, use the current stack frame.
2338 if (!TBTable->tb.stores_bc)
2339 lastStack = curStack;
2340
2341 // Return address is the address after call site instruction.
2342 pint_t returnAddress;
2343
2344 if (isSignalFrame) {
2345 _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
2346 reinterpret_cast<void *>(lastStack));
2347
2348 sigcontext *sigContext = reinterpret_cast<sigcontext *>(
2349 reinterpret_cast<char *>(lastStack) + STKMINALIGN);
2350 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2351
2352 bool useSTKMIN = false;
2353 if (returnAddress < 0x10000000) {
2354 // Try again using STKMIN.
2355 sigContext = reinterpret_cast<sigcontext *>(
2356 reinterpret_cast<char *>(lastStack) + STKMIN);
2357 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2358 if (returnAddress < 0x10000000) {
2359 _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p from sigcontext=%p",
2360 reinterpret_cast<void *>(returnAddress),
2361 reinterpret_cast<void *>(sigContext));
2362 return UNW_EBADFRAME;
2363 }
2364 useSTKMIN = true;
2365 }
2366 _LIBUNWIND_TRACE_UNWINDING("Returning from a signal handler %s: "
2367 "sigContext=%p, returnAddress=%p. "
2368 "Seems to be a valid address",
2369 useSTKMIN ? "STKMIN" : "STKMINALIGN",
2370 reinterpret_cast<void *>(sigContext),
2371 reinterpret_cast<void *>(returnAddress));
2372
2373 // Restore the condition register from sigcontext.
2374 newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
2375
2376 // Save the LR in sigcontext for stepping up when the function that
2377 // raised the signal is a leaf function. This LR has the return address
2378 // to the caller of the leaf function.
2379 newRegisters.setLR(sigContext->sc_jmpbuf.jmp_context.lr);
2380 _LIBUNWIND_TRACE_UNWINDING(
2381 "Save LR=%p from sigcontext",
2382 reinterpret_cast<void *>(sigContext->sc_jmpbuf.jmp_context.lr));
2383
2384 // Restore GPRs from sigcontext.
2385 for (int i = 0; i < 32; ++i)
2386 newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
2387
2388 // Restore FPRs from sigcontext.
2389 for (int i = 0; i < 32; ++i)
2390 newRegisters.setFloatRegister(i + unwPPCF0Index,
2391 sigContext->sc_jmpbuf.jmp_context.fpr[i]);
2392
2393 // Restore vector registers if there is an associated extended context
2394 // structure.
2395 if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
2396 ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
2397 if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
2398 for (int i = 0; i < 32; ++i)
2399 newRegisters.setVectorRegister(
2400 i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
2401 &(uContext->__extctx->__vmx.__vr[i]))));
2402 }
2403 }
2404 } else {
2405 // Step up a normal frame.
2406
2407 if (!TBTable->tb.saves_lr && registers.getLR()) {
2408 // This case should only occur if we were called from a signal handler
2409 // and the signal occurred in a function that doesn't save the LR.
2410 returnAddress = static_cast<pint_t>(registers.getLR());
2411 _LIBUNWIND_TRACE_UNWINDING("Use saved LR=%p",
2412 reinterpret_cast<void *>(returnAddress));
2413 } else {
2414 // Otherwise, use the LR value in the stack link area.
2415 returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
2416 }
2417
2418 // Reset LR in the current context.
2419 newRegisters.setLR(NULL);
2420
2421 _LIBUNWIND_TRACE_UNWINDING(
2422 "Extract info from lastStack=%p, returnAddress=%p",
2423 reinterpret_cast<void *>(lastStack),
2424 reinterpret_cast<void *>(returnAddress));
2425 _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d",
2426 TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
2427 TBTable->tb.saves_cr);
2428
2429 // Restore FP registers.
2430 char *ptrToRegs = reinterpret_cast<char *>(lastStack);
2431 double *FPRegs = reinterpret_cast<double *>(
2432 ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
2433 for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
2434 newRegisters.setFloatRegister(
2435 32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
2436
2437 // Restore GP registers.
2438 ptrToRegs = reinterpret_cast<char *>(FPRegs);
2439 uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
2440 ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
2441 for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
2442 newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
2443
2444 // Restore Vector registers.
2445 ptrToRegs = reinterpret_cast<char *>(GPRegs);
2446
2447 // Restore vector registers only if this is a Clang frame. Also
2448 // check if traceback table bit has_vec is set. If it is, structure
2449 // vec_ext is available.
2450 if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
2451
2452 // Get to the vec_ext structure to check if vector registers are saved.
2453 uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2454
2455 // Skip field parminfo if exists.
2456 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2457 ++p;
2458
2459 // Skip field tb_offset if exists.
2460 if (TBTable->tb.has_tboff)
2461 ++p;
2462
2463 // Skip field hand_mask if exists.
2464 if (TBTable->tb.int_hndl)
2465 ++p;
2466
2467 // Skip fields ctl_info and ctl_info_disp if exist.
2468 if (TBTable->tb.has_ctl) {
2469 // Skip field ctl_info.
2470 ++p;
2471 // Skip field ctl_info_disp.
2472 ++p;
2473 }
2474
2475 // Skip fields name_len and name if exist.
2476 // p is supposed to point to field name_len now.
2477 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2478 if (TBTable->tb.name_present) {
2479 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2480 charPtr = charPtr + name_len + sizeof(uint16_t);
2481 }
2482
2483 // Skip field alloc_reg if it exists.
2484 if (TBTable->tb.uses_alloca)
2485 ++charPtr;
2486
2487 struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
2488
2489 _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d", vec_ext->vr_saved);
2490
2491 // Restore vector register(s) if saved on the stack.
2492 if (vec_ext->vr_saved) {
2493 // Saved vector registers are 16-byte aligned.
2494 if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
2495 ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
2496 v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
2497 sizeof(v128));
2498 for (int i = 0; i < vec_ext->vr_saved; ++i) {
2499 newRegisters.setVectorRegister(
2500 32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
2501 }
2502 }
2503 }
2504 if (TBTable->tb.saves_cr) {
2505 // Get the saved condition register. The condition register is only
2506 // a single word.
2507 newRegisters.setCR(
2508 *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
2509 }
2510
2511 // Restore the SP.
2512 newRegisters.setSP(lastStack);
2513
2514 // The first instruction after return.
2515 uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
2516
2517 // Do we need to set the TOC register?
2518 _LIBUNWIND_TRACE_UNWINDING(
2519 "Current gpr2=%p",
2520 reinterpret_cast<void *>(newRegisters.getRegister(2)));
2521 if (firstInstruction == loadTOCRegInst) {
2522 _LIBUNWIND_TRACE_UNWINDING(
2523 "Set gpr2=%p from frame",
2524 reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
2525 newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
2526 }
2527 }
2528 _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
2529 reinterpret_cast<void *>(lastStack),
2530 reinterpret_cast<void *>(returnAddress),
2531 reinterpret_cast<void *>(pc));
2532
2533 // The return address is the address after call site instruction, so
2534 // setting IP to that simulates a return.
2535 newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
2536
2537 // Simulate the step by replacing the register set with the new ones.
2538 registers = newRegisters;
2539
2540 // Check if the next frame is a signal frame.
2541 pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2542
2543 // Return address is the address after call site instruction.
2544 pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
2545
2546 if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
2547 _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
2548 "nextStack=%p, next return address=%p\n",
2549 reinterpret_cast<void *>(nextStack),
2550 reinterpret_cast<void *>(nextReturnAddress));
2551 isSignalFrame = true;
2552 } else {
2553 isSignalFrame = false;
2554 }
2555 return UNW_STEP_SUCCESS;
2556 }
2557 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2558
2559 template <typename A, typename R>
setInfoBasedOnIPRegister(bool isReturnAddress)2560 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
2561 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2562 _isSigReturn = false;
2563 #endif
2564
2565 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2566 #if defined(_LIBUNWIND_ARM_EHABI)
2567 // Remove the thumb bit so the IP represents the actual instruction address.
2568 // This matches the behaviour of _Unwind_GetIP on arm.
2569 pc &= (pint_t)~0x1;
2570 #endif
2571
2572 // Exit early if at the top of the stack.
2573 if (pc == 0) {
2574 _unwindInfoMissing = true;
2575 return;
2576 }
2577
2578 // If the last line of a function is a "throw" the compiler sometimes
2579 // emits no instructions after the call to __cxa_throw. This means
2580 // the return address is actually the start of the next function.
2581 // To disambiguate this, back up the pc when we know it is a return
2582 // address.
2583 if (isReturnAddress)
2584 #if defined(_AIX)
2585 // PC needs to be a 4-byte aligned address to be able to look for a
2586 // word of 0 that indicates the start of the traceback table at the end
2587 // of a function on AIX.
2588 pc -= 4;
2589 #else
2590 --pc;
2591 #endif
2592
2593 // Ask address space object to find unwind sections for this pc.
2594 UnwindInfoSections sects;
2595 if (_addressSpace.findUnwindSections(pc, sects)) {
2596 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2597 // If there is a compact unwind encoding table, look there first.
2598 if (sects.compact_unwind_section != 0) {
2599 if (this->getInfoFromCompactEncodingSection(pc, sects)) {
2600 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2601 // Found info in table, done unless encoding says to use dwarf.
2602 uint32_t dwarfOffset;
2603 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
2604 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
2605 // found info in dwarf, done
2606 return;
2607 }
2608 }
2609 #endif
2610 // If unwind table has entry, but entry says there is no unwind info,
2611 // record that we have no unwind info.
2612 if (_info.format == 0)
2613 _unwindInfoMissing = true;
2614 return;
2615 }
2616 }
2617 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2618
2619 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2620 // If there is SEH unwind info, look there next.
2621 if (this->getInfoFromSEH(pc))
2622 return;
2623 #endif
2624
2625 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2626 // If there is unwind info in the traceback table, look there next.
2627 if (this->getInfoFromTBTable(pc, _registers))
2628 return;
2629 #endif
2630
2631 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2632 // If there is dwarf unwind info, look there next.
2633 if (sects.dwarf_section != 0) {
2634 if (this->getInfoFromDwarfSection(pc, sects)) {
2635 // found info in dwarf, done
2636 return;
2637 }
2638 }
2639 #endif
2640
2641 #if defined(_LIBUNWIND_ARM_EHABI)
2642 // If there is ARM EHABI unwind info, look there next.
2643 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
2644 return;
2645 #endif
2646 }
2647
2648 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2649 // There is no static unwind info for this pc. Look to see if an FDE was
2650 // dynamically registered for it.
2651 pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
2652 pc);
2653 if (cachedFDE != 0) {
2654 typename CFI_Parser<A>::FDE_Info fdeInfo;
2655 typename CFI_Parser<A>::CIE_Info cieInfo;
2656 if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
2657 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2658 return;
2659 }
2660
2661 // Lastly, ask AddressSpace object about platform specific ways to locate
2662 // other FDEs.
2663 pint_t fde;
2664 if (_addressSpace.findOtherFDE(pc, fde)) {
2665 typename CFI_Parser<A>::FDE_Info fdeInfo;
2666 typename CFI_Parser<A>::CIE_Info cieInfo;
2667 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
2668 // Double check this FDE is for a function that includes the pc.
2669 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
2670 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2671 return;
2672 }
2673 }
2674 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2675
2676 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2677 if (setInfoForSigReturn())
2678 return;
2679 #endif
2680
2681 // no unwind info, flag that we can't reliably unwind
2682 _unwindInfoMissing = true;
2683 }
2684
2685 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2686 defined(_LIBUNWIND_TARGET_AARCH64)
2687 template <typename A, typename R>
setInfoForSigReturn(Registers_arm64 &)2688 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
2689 // Look for the sigreturn trampoline. The trampoline's body is two
2690 // specific instructions (see below). Typically the trampoline comes from the
2691 // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
2692 // own restorer function, though, or user-mode QEMU might write a trampoline
2693 // onto the stack.
2694 //
2695 // This special code path is a fallback that is only used if the trampoline
2696 // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
2697 // constant for the PC needs to be defined before DWARF can handle a signal
2698 // trampoline. This code may segfault if the target PC is unreadable, e.g.:
2699 // - The PC points at a function compiled without unwind info, and which is
2700 // part of an execute-only mapping (e.g. using -Wl,--execute-only).
2701 // - The PC is invalid and happens to point to unreadable or unmapped memory.
2702 //
2703 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
2704 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2705 // The PC might contain an invalid address if the unwind info is bad, so
2706 // directly accessing it could cause a SIGSEGV.
2707 if (!isReadableAddr(pc))
2708 return false;
2709 auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2710 // Look for instructions: mov x8, #0x8b; svc #0x0
2711 if (instructions[0] != 0xd2801168 || instructions[1] != 0xd4000001)
2712 return false;
2713
2714 _info = {};
2715 _info.start_ip = pc;
2716 _info.end_ip = pc + 4;
2717 _isSigReturn = true;
2718 return true;
2719 }
2720
2721 template <typename A, typename R>
stepThroughSigReturn(Registers_arm64 &)2722 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
2723 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2724 // - 128-byte siginfo struct
2725 // - ucontext struct:
2726 // - 8-byte long (uc_flags)
2727 // - 8-byte pointer (uc_link)
2728 // - 24-byte stack_t
2729 // - 128-byte signal set
2730 // - 8 bytes of padding because sigcontext has 16-byte alignment
2731 // - sigcontext/mcontext_t
2732 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
2733 const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
2734
2735 // Offsets from sigcontext to each register.
2736 const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
2737 const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
2738 const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
2739
2740 pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2741
2742 for (int i = 0; i <= 30; ++i) {
2743 uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
2744 static_cast<pint_t>(i * 8));
2745 _registers.setRegister(UNW_AARCH64_X0 + i, value);
2746 }
2747 _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
2748 _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
2749 _isSignalFrame = true;
2750 return UNW_STEP_SUCCESS;
2751 }
2752 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2753 // defined(_LIBUNWIND_TARGET_AARCH64)
2754
2755 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2756 defined(_LIBUNWIND_TARGET_RISCV)
2757 template <typename A, typename R>
setInfoForSigReturn(Registers_riscv &)2758 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_riscv &) {
2759 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2760 // The PC might contain an invalid address if the unwind info is bad, so
2761 // directly accessing it could cause a SIGSEGV.
2762 if (!isReadableAddr(pc))
2763 return false;
2764 const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2765 // Look for the two instructions used in the sigreturn trampoline
2766 // __vdso_rt_sigreturn:
2767 //
2768 // 0x08b00893 li a7,0x8b
2769 // 0x00000073 ecall
2770 if (instructions[0] != 0x08b00893 || instructions[1] != 0x00000073)
2771 return false;
2772
2773 _info = {};
2774 _info.start_ip = pc;
2775 _info.end_ip = pc + 4;
2776 _isSigReturn = true;
2777 return true;
2778 }
2779
2780 template <typename A, typename R>
stepThroughSigReturn(Registers_riscv &)2781 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_riscv &) {
2782 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2783 // - 128-byte siginfo struct
2784 // - ucontext_t struct:
2785 // - 8-byte long (__uc_flags)
2786 // - 8-byte pointer (*uc_link)
2787 // - 24-byte uc_stack
2788 // - 8-byte uc_sigmask
2789 // - 120-byte of padding to allow sigset_t to be expanded in the future
2790 // - 8 bytes of padding because sigcontext has 16-byte alignment
2791 // - struct sigcontext uc_mcontext
2792 // [1]
2793 // https://github.com/torvalds/linux/blob/master/arch/riscv/kernel/signal.c
2794 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2795
2796 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2797 _registers.setIP(_addressSpace.get64(sigctx));
2798 for (int i = UNW_RISCV_X1; i <= UNW_RISCV_X31; ++i) {
2799 uint64_t value = _addressSpace.get64(sigctx + static_cast<pint_t>(i * 8));
2800 _registers.setRegister(i, value);
2801 }
2802 _isSignalFrame = true;
2803 return UNW_STEP_SUCCESS;
2804 }
2805 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2806 // defined(_LIBUNWIND_TARGET_RISCV)
2807
2808 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2809 defined(_LIBUNWIND_TARGET_S390X)
2810 template <typename A, typename R>
setInfoForSigReturn(Registers_s390x &)2811 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
2812 // Look for the sigreturn trampoline. The trampoline's body is a
2813 // specific instruction (see below). Typically the trampoline comes from the
2814 // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its
2815 // own restorer function, though, or user-mode QEMU might write a trampoline
2816 // onto the stack.
2817 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2818 // The PC might contain an invalid address if the unwind info is bad, so
2819 // directly accessing it could cause a SIGSEGV.
2820 if (!isReadableAddr(pc))
2821 return false;
2822 const auto inst = *reinterpret_cast<const uint16_t *>(pc);
2823 if (inst == 0x0a77 || inst == 0x0aad) {
2824 _info = {};
2825 _info.start_ip = pc;
2826 _info.end_ip = pc + 2;
2827 _isSigReturn = true;
2828 return true;
2829 }
2830 return false;
2831 }
2832
2833 template <typename A, typename R>
stepThroughSigReturn(Registers_s390x &)2834 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
2835 // Determine current SP.
2836 const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP));
2837 // According to the s390x ABI, the CFA is at (incoming) SP + 160.
2838 const pint_t cfa = sp + 160;
2839
2840 // Determine current PC and instruction there (this must be either
2841 // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn").
2842 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2843 const uint16_t inst = _addressSpace.get16(pc);
2844
2845 // Find the addresses of the signo and sigcontext in the frame.
2846 pint_t pSigctx = 0;
2847 pint_t pSigno = 0;
2848
2849 // "svc __NR_sigreturn" uses a non-RT signal trampoline frame.
2850 if (inst == 0x0a77) {
2851 // Layout of a non-RT signal trampoline frame, starting at the CFA:
2852 // - 8-byte signal mask
2853 // - 8-byte pointer to sigcontext, followed by signo
2854 // - 4-byte signo
2855 pSigctx = _addressSpace.get64(cfa + 8);
2856 pSigno = pSigctx + 344;
2857 }
2858
2859 // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame.
2860 if (inst == 0x0aad) {
2861 // Layout of a RT signal trampoline frame, starting at the CFA:
2862 // - 8-byte retcode (+ alignment)
2863 // - 128-byte siginfo struct (starts with signo)
2864 // - ucontext struct:
2865 // - 8-byte long (uc_flags)
2866 // - 8-byte pointer (uc_link)
2867 // - 24-byte stack_t
2868 // - 8 bytes of padding because sigcontext has 16-byte alignment
2869 // - sigcontext/mcontext_t
2870 pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8;
2871 pSigno = cfa + 8;
2872 }
2873
2874 assert(pSigctx != 0);
2875 assert(pSigno != 0);
2876
2877 // Offsets from sigcontext to each register.
2878 const pint_t kOffsetPc = 8;
2879 const pint_t kOffsetGprs = 16;
2880 const pint_t kOffsetFprs = 216;
2881
2882 // Restore all registers.
2883 for (int i = 0; i < 16; ++i) {
2884 uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs +
2885 static_cast<pint_t>(i * 8));
2886 _registers.setRegister(UNW_S390X_R0 + i, value);
2887 }
2888 for (int i = 0; i < 16; ++i) {
2889 static const int fpr[16] = {
2890 UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3,
2891 UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7,
2892 UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11,
2893 UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15
2894 };
2895 double value = _addressSpace.getDouble(pSigctx + kOffsetFprs +
2896 static_cast<pint_t>(i * 8));
2897 _registers.setFloatRegister(fpr[i], value);
2898 }
2899 _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc));
2900
2901 // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
2902 // after the faulting instruction rather than before it.
2903 // Do not set _isSignalFrame in that case.
2904 uint32_t signo = _addressSpace.get32(pSigno);
2905 _isSignalFrame = (signo != 4 && signo != 5 && signo != 8);
2906
2907 return UNW_STEP_SUCCESS;
2908 }
2909 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2910 // defined(_LIBUNWIND_TARGET_S390X)
2911
step(bool stage2)2912 template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
2913 (void)stage2;
2914 // Bottom of stack is defined is when unwind info cannot be found.
2915 if (_unwindInfoMissing)
2916 return UNW_STEP_END;
2917
2918 // Use unwinding info to modify register set as if function returned.
2919 int result;
2920 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2921 if (_isSigReturn) {
2922 result = this->stepThroughSigReturn();
2923 } else
2924 #endif
2925 {
2926 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2927 result = this->stepWithCompactEncoding(stage2);
2928 #elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2929 result = this->stepWithSEHData();
2930 #elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2931 result = this->stepWithTBTableData();
2932 #elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2933 result = this->stepWithDwarfFDE(stage2);
2934 #elif defined(_LIBUNWIND_ARM_EHABI)
2935 result = this->stepWithEHABI();
2936 #else
2937 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
2938 _LIBUNWIND_SUPPORT_SEH_UNWIND or \
2939 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
2940 _LIBUNWIND_ARM_EHABI
2941 #endif
2942 }
2943
2944 // update info based on new PC
2945 if (result == UNW_STEP_SUCCESS) {
2946 this->setInfoBasedOnIPRegister(true);
2947 if (_unwindInfoMissing)
2948 return UNW_STEP_END;
2949 }
2950
2951 return result;
2952 }
2953
2954 template <typename A, typename R>
getInfo(unw_proc_info_t * info)2955 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
2956 if (_unwindInfoMissing)
2957 memset(info, 0, sizeof(*info));
2958 else
2959 *info = _info;
2960 }
2961
2962 template <typename A, typename R>
getFunctionName(char * buf,size_t bufLen,unw_word_t * offset)2963 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
2964 unw_word_t *offset) {
2965 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
2966 buf, bufLen, offset);
2967 }
2968
2969 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2970 template <typename A, typename R>
isReadableAddr(const pint_t addr) const2971 bool UnwindCursor<A, R>::isReadableAddr(const pint_t addr) const {
2972 // We use SYS_rt_sigprocmask, inspired by Abseil's AddressIsReadable.
2973
2974 const auto sigsetAddr = reinterpret_cast<sigset_t *>(addr);
2975 // We have to check that addr is nullptr because sigprocmask allows that
2976 // as an argument without failure.
2977 if (!sigsetAddr)
2978 return false;
2979 const auto saveErrno = errno;
2980 // We MUST use a raw syscall here, as wrappers may try to access
2981 // sigsetAddr which may cause a SIGSEGV. A raw syscall however is
2982 // safe. Additionally, we need to pass the kernel_sigset_size, which is
2983 // different from libc sizeof(sigset_t). For the majority of architectures,
2984 // it's 64 bits (_NSIG), and libc NSIG is _NSIG + 1.
2985 const auto kernelSigsetSize = NSIG / 8;
2986 [[maybe_unused]] const int Result = syscall(
2987 SYS_rt_sigprocmask, /*how=*/~0, sigsetAddr, nullptr, kernelSigsetSize);
2988 // Because our "how" is invalid, this syscall should always fail, and our
2989 // errno should always be EINVAL or an EFAULT. This relies on the Linux
2990 // kernel to check copy_from_user before checking if the "how" argument is
2991 // invalid.
2992 assert(Result == -1);
2993 assert(errno == EFAULT || errno == EINVAL);
2994 const auto readable = errno != EFAULT;
2995 errno = saveErrno;
2996 return readable;
2997 }
2998 #endif
2999
3000 #if defined(_LIBUNWIND_USE_CET)
__libunwind_cet_get_registers(unw_cursor_t * cursor)3001 extern "C" void *__libunwind_cet_get_registers(unw_cursor_t *cursor) {
3002 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
3003 return co->get_registers();
3004 }
3005 #endif
3006 } // namespace libunwind
3007
3008 #endif // __UNWINDCURSOR_HPP__
3009