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 <unistd.h>
40 #define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
41 #endif
42
43 #include "AddressSpace.hpp"
44 #include "CompactUnwinder.hpp"
45 #include "config.h"
46 #include "DwarfInstructions.hpp"
47 #include "EHHeaderParser.hpp"
48 #include "libunwind.h"
49 #include "libunwind_ext.h"
50 #include "Registers.hpp"
51 #include "RWMutex.hpp"
52 #include "Unwind-EHABI.h"
53
54 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
55 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
56 // earlier) SDKs.
57 // MinGW-w64 has always provided this struct.
58 #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
59 !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
60 struct _DISPATCHER_CONTEXT {
61 ULONG64 ControlPc;
62 ULONG64 ImageBase;
63 PRUNTIME_FUNCTION FunctionEntry;
64 ULONG64 EstablisherFrame;
65 ULONG64 TargetIp;
66 PCONTEXT ContextRecord;
67 PEXCEPTION_ROUTINE LanguageHandler;
68 PVOID HandlerData;
69 PUNWIND_HISTORY_TABLE HistoryTable;
70 ULONG ScopeIndex;
71 ULONG Fill0;
72 };
73 #endif
74
75 struct UNWIND_INFO {
76 uint8_t Version : 3;
77 uint8_t Flags : 5;
78 uint8_t SizeOfProlog;
79 uint8_t CountOfCodes;
80 uint8_t FrameRegister : 4;
81 uint8_t FrameOffset : 4;
82 uint16_t UnwindCodes[2];
83 };
84
85 extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
86 int, _Unwind_Action, uint64_t, _Unwind_Exception *,
87 struct _Unwind_Context *);
88
89 #endif
90
91 namespace libunwind {
92
93 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
94 /// Cache of recently found FDEs.
95 template <typename A>
96 class _LIBUNWIND_HIDDEN DwarfFDECache {
97 typedef typename A::pint_t pint_t;
98 public:
99 static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
100 static pint_t findFDE(pint_t mh, pint_t pc);
101 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
102 static void removeAllIn(pint_t mh);
103 static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
104 unw_word_t ip_end,
105 unw_word_t fde, unw_word_t mh));
106
107 private:
108
109 struct entry {
110 pint_t mh;
111 pint_t ip_start;
112 pint_t ip_end;
113 pint_t fde;
114 };
115
116 // These fields are all static to avoid needing an initializer.
117 // There is only one instance of this class per process.
118 static RWMutex _lock;
119 #ifdef __APPLE__
120 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
121 static bool _registeredForDyldUnloads;
122 #endif
123 static entry *_buffer;
124 static entry *_bufferUsed;
125 static entry *_bufferEnd;
126 static entry _initialBuffer[64];
127 };
128
129 template <typename A>
130 typename DwarfFDECache<A>::entry *
131 DwarfFDECache<A>::_buffer = _initialBuffer;
132
133 template <typename A>
134 typename DwarfFDECache<A>::entry *
135 DwarfFDECache<A>::_bufferUsed = _initialBuffer;
136
137 template <typename A>
138 typename DwarfFDECache<A>::entry *
139 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
140
141 template <typename A>
142 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
143
144 template <typename A>
145 RWMutex DwarfFDECache<A>::_lock;
146
147 #ifdef __APPLE__
148 template <typename A>
149 bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
150 #endif
151
152 template <typename A>
findFDE(pint_t mh,pint_t pc)153 typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) {
154 pint_t result = 0;
155 _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
156 for (entry *p = _buffer; p < _bufferUsed; ++p) {
157 if ((mh == p->mh) || (mh == kSearchAll)) {
158 if ((p->ip_start <= pc) && (pc < p->ip_end)) {
159 result = p->fde;
160 break;
161 }
162 }
163 }
164 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
165 return result;
166 }
167
168 template <typename A>
add(pint_t mh,pint_t ip_start,pint_t ip_end,pint_t fde)169 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
170 pint_t fde) {
171 #if !defined(_LIBUNWIND_NO_HEAP)
172 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
173 if (_bufferUsed >= _bufferEnd) {
174 size_t oldSize = (size_t)(_bufferEnd - _buffer);
175 size_t newSize = oldSize * 4;
176 // Can't use operator new (we are below it).
177 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
178 memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
179 if (_buffer != _initialBuffer)
180 free(_buffer);
181 _buffer = newBuffer;
182 _bufferUsed = &newBuffer[oldSize];
183 _bufferEnd = &newBuffer[newSize];
184 }
185 _bufferUsed->mh = mh;
186 _bufferUsed->ip_start = ip_start;
187 _bufferUsed->ip_end = ip_end;
188 _bufferUsed->fde = fde;
189 ++_bufferUsed;
190 #ifdef __APPLE__
191 if (!_registeredForDyldUnloads) {
192 _dyld_register_func_for_remove_image(&dyldUnloadHook);
193 _registeredForDyldUnloads = true;
194 }
195 #endif
196 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
197 #endif
198 }
199
200 template <typename A>
removeAllIn(pint_t mh)201 void DwarfFDECache<A>::removeAllIn(pint_t mh) {
202 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
203 entry *d = _buffer;
204 for (const entry *s = _buffer; s < _bufferUsed; ++s) {
205 if (s->mh != mh) {
206 if (d != s)
207 *d = *s;
208 ++d;
209 }
210 }
211 _bufferUsed = d;
212 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
213 }
214
215 #ifdef __APPLE__
216 template <typename A>
dyldUnloadHook(const struct mach_header * mh,intptr_t)217 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
218 removeAllIn((pint_t) mh);
219 }
220 #endif
221
222 template <typename A>
iterateCacheEntries(void (* func)(unw_word_t ip_start,unw_word_t ip_end,unw_word_t fde,unw_word_t mh))223 void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
224 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
225 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
226 for (entry *p = _buffer; p < _bufferUsed; ++p) {
227 (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
228 }
229 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
230 }
231 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
232
233
234 #define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field))
235
236 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
237 template <typename A> class UnwindSectionHeader {
238 public:
UnwindSectionHeader(A & addressSpace,typename A::pint_t addr)239 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
240 : _addressSpace(addressSpace), _addr(addr) {}
241
version() const242 uint32_t version() const {
243 return _addressSpace.get32(_addr +
244 offsetof(unwind_info_section_header, version));
245 }
commonEncodingsArraySectionOffset() const246 uint32_t commonEncodingsArraySectionOffset() const {
247 return _addressSpace.get32(_addr +
248 offsetof(unwind_info_section_header,
249 commonEncodingsArraySectionOffset));
250 }
commonEncodingsArrayCount() const251 uint32_t commonEncodingsArrayCount() const {
252 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
253 commonEncodingsArrayCount));
254 }
personalityArraySectionOffset() const255 uint32_t personalityArraySectionOffset() const {
256 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
257 personalityArraySectionOffset));
258 }
personalityArrayCount() const259 uint32_t personalityArrayCount() const {
260 return _addressSpace.get32(
261 _addr + offsetof(unwind_info_section_header, personalityArrayCount));
262 }
indexSectionOffset() const263 uint32_t indexSectionOffset() const {
264 return _addressSpace.get32(
265 _addr + offsetof(unwind_info_section_header, indexSectionOffset));
266 }
indexCount() const267 uint32_t indexCount() const {
268 return _addressSpace.get32(
269 _addr + offsetof(unwind_info_section_header, indexCount));
270 }
271
272 private:
273 A &_addressSpace;
274 typename A::pint_t _addr;
275 };
276
277 template <typename A> class UnwindSectionIndexArray {
278 public:
UnwindSectionIndexArray(A & addressSpace,typename A::pint_t addr)279 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
280 : _addressSpace(addressSpace), _addr(addr) {}
281
functionOffset(uint32_t index) const282 uint32_t functionOffset(uint32_t index) const {
283 return _addressSpace.get32(
284 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
285 functionOffset));
286 }
secondLevelPagesSectionOffset(uint32_t index) const287 uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
288 return _addressSpace.get32(
289 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
290 secondLevelPagesSectionOffset));
291 }
lsdaIndexArraySectionOffset(uint32_t index) const292 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
293 return _addressSpace.get32(
294 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
295 lsdaIndexArraySectionOffset));
296 }
297
298 private:
299 A &_addressSpace;
300 typename A::pint_t _addr;
301 };
302
303 template <typename A> class UnwindSectionRegularPageHeader {
304 public:
UnwindSectionRegularPageHeader(A & addressSpace,typename A::pint_t addr)305 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
306 : _addressSpace(addressSpace), _addr(addr) {}
307
kind() const308 uint32_t kind() const {
309 return _addressSpace.get32(
310 _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
311 }
entryPageOffset() const312 uint16_t entryPageOffset() const {
313 return _addressSpace.get16(
314 _addr + offsetof(unwind_info_regular_second_level_page_header,
315 entryPageOffset));
316 }
entryCount() const317 uint16_t entryCount() const {
318 return _addressSpace.get16(
319 _addr +
320 offsetof(unwind_info_regular_second_level_page_header, entryCount));
321 }
322
323 private:
324 A &_addressSpace;
325 typename A::pint_t _addr;
326 };
327
328 template <typename A> class UnwindSectionRegularArray {
329 public:
UnwindSectionRegularArray(A & addressSpace,typename A::pint_t addr)330 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
331 : _addressSpace(addressSpace), _addr(addr) {}
332
functionOffset(uint32_t index) const333 uint32_t functionOffset(uint32_t index) const {
334 return _addressSpace.get32(
335 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
336 functionOffset));
337 }
encoding(uint32_t index) const338 uint32_t encoding(uint32_t index) const {
339 return _addressSpace.get32(
340 _addr +
341 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
342 }
343
344 private:
345 A &_addressSpace;
346 typename A::pint_t _addr;
347 };
348
349 template <typename A> class UnwindSectionCompressedPageHeader {
350 public:
UnwindSectionCompressedPageHeader(A & addressSpace,typename A::pint_t addr)351 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
352 : _addressSpace(addressSpace), _addr(addr) {}
353
kind() const354 uint32_t kind() const {
355 return _addressSpace.get32(
356 _addr +
357 offsetof(unwind_info_compressed_second_level_page_header, kind));
358 }
entryPageOffset() const359 uint16_t entryPageOffset() const {
360 return _addressSpace.get16(
361 _addr + offsetof(unwind_info_compressed_second_level_page_header,
362 entryPageOffset));
363 }
entryCount() const364 uint16_t entryCount() const {
365 return _addressSpace.get16(
366 _addr +
367 offsetof(unwind_info_compressed_second_level_page_header, entryCount));
368 }
encodingsPageOffset() const369 uint16_t encodingsPageOffset() const {
370 return _addressSpace.get16(
371 _addr + offsetof(unwind_info_compressed_second_level_page_header,
372 encodingsPageOffset));
373 }
encodingsCount() const374 uint16_t encodingsCount() const {
375 return _addressSpace.get16(
376 _addr + offsetof(unwind_info_compressed_second_level_page_header,
377 encodingsCount));
378 }
379
380 private:
381 A &_addressSpace;
382 typename A::pint_t _addr;
383 };
384
385 template <typename A> class UnwindSectionCompressedArray {
386 public:
UnwindSectionCompressedArray(A & addressSpace,typename A::pint_t addr)387 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
388 : _addressSpace(addressSpace), _addr(addr) {}
389
functionOffset(uint32_t index) const390 uint32_t functionOffset(uint32_t index) const {
391 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
392 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
393 }
encodingIndex(uint32_t index) const394 uint16_t encodingIndex(uint32_t index) const {
395 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
396 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
397 }
398
399 private:
400 A &_addressSpace;
401 typename A::pint_t _addr;
402 };
403
404 template <typename A> class UnwindSectionLsdaArray {
405 public:
UnwindSectionLsdaArray(A & addressSpace,typename A::pint_t addr)406 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
407 : _addressSpace(addressSpace), _addr(addr) {}
408
functionOffset(uint32_t index) const409 uint32_t functionOffset(uint32_t index) const {
410 return _addressSpace.get32(
411 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
412 index, functionOffset));
413 }
lsdaOffset(uint32_t index) const414 uint32_t lsdaOffset(uint32_t index) const {
415 return _addressSpace.get32(
416 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
417 index, lsdaOffset));
418 }
419
420 private:
421 A &_addressSpace;
422 typename A::pint_t _addr;
423 };
424 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
425
426 class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
427 public:
428 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
429 // This avoids an unnecessary dependency to libc++abi.
operator delete(void *,size_t)430 void operator delete(void *, size_t) {}
431
~AbstractUnwindCursor()432 virtual ~AbstractUnwindCursor() {}
validReg(int)433 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
getReg(int)434 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
setReg(int,unw_word_t)435 virtual void setReg(int, unw_word_t) {
436 _LIBUNWIND_ABORT("setReg not implemented");
437 }
validFloatReg(int)438 virtual bool validFloatReg(int) {
439 _LIBUNWIND_ABORT("validFloatReg not implemented");
440 }
getFloatReg(int)441 virtual unw_fpreg_t getFloatReg(int) {
442 _LIBUNWIND_ABORT("getFloatReg not implemented");
443 }
setFloatReg(int,unw_fpreg_t)444 virtual void setFloatReg(int, unw_fpreg_t) {
445 _LIBUNWIND_ABORT("setFloatReg not implemented");
446 }
step(bool=false)447 virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); }
getInfo(unw_proc_info_t *)448 virtual void getInfo(unw_proc_info_t *) {
449 _LIBUNWIND_ABORT("getInfo not implemented");
450 }
jumpto()451 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
isSignalFrame()452 virtual bool isSignalFrame() {
453 _LIBUNWIND_ABORT("isSignalFrame not implemented");
454 }
getFunctionName(char *,size_t,unw_word_t *)455 virtual bool getFunctionName(char *, size_t, unw_word_t *) {
456 _LIBUNWIND_ABORT("getFunctionName not implemented");
457 }
setInfoBasedOnIPRegister(bool=false)458 virtual void setInfoBasedOnIPRegister(bool = false) {
459 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
460 }
getRegisterName(int)461 virtual const char *getRegisterName(int) {
462 _LIBUNWIND_ABORT("getRegisterName not implemented");
463 }
464 #ifdef __arm__
saveVFPAsX()465 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
466 #endif
467
468 #ifdef _AIX
getDataRelBase()469 virtual uintptr_t getDataRelBase() {
470 _LIBUNWIND_ABORT("getDataRelBase not implemented");
471 }
472 #endif
473
474 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
get_registers()475 virtual void *get_registers() {
476 _LIBUNWIND_ABORT("get_registers not implemented");
477 }
478 #endif
479 };
480
481 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
482
483 /// \c UnwindCursor contains all state (including all register values) during
484 /// an unwind. This is normally stack-allocated inside a unw_cursor_t.
485 template <typename A, typename R>
486 class UnwindCursor : public AbstractUnwindCursor {
487 typedef typename A::pint_t pint_t;
488 public:
489 UnwindCursor(unw_context_t *context, A &as);
490 UnwindCursor(CONTEXT *context, A &as);
491 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()492 virtual ~UnwindCursor() {}
493 virtual bool validReg(int);
494 virtual unw_word_t getReg(int);
495 virtual void setReg(int, unw_word_t);
496 virtual bool validFloatReg(int);
497 virtual unw_fpreg_t getFloatReg(int);
498 virtual void setFloatReg(int, unw_fpreg_t);
499 virtual int step(bool = false);
500 virtual void getInfo(unw_proc_info_t *);
501 virtual void jumpto();
502 virtual bool isSignalFrame();
503 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
504 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
505 virtual const char *getRegisterName(int num);
506 #ifdef __arm__
507 virtual void saveVFPAsX();
508 #endif
509
getDispatcherContext()510 DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
setDispatcherContext(DISPATCHER_CONTEXT * disp)511 void setDispatcherContext(DISPATCHER_CONTEXT *disp) {
512 _dispContext = *disp;
513 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
514 if (_dispContext.LanguageHandler) {
515 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
516 } else
517 _info.handler = 0;
518 }
519
520 // libunwind does not and should not depend on C++ library which means that we
521 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)522 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
523
524 private:
525
getLastPC() const526 pint_t getLastPC() const { return _dispContext.ControlPc; }
setLastPC(pint_t pc)527 void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)528 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
529 #ifdef __arm__
530 // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit.
531 pc &= ~1U;
532 #endif
533 // If pc points exactly at the end of the range, we might resolve the
534 // next function instead. Decrement pc by 1 to fit inside the current
535 // function.
536 pc -= 1;
537 _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
538 &_dispContext.ImageBase,
539 _dispContext.HistoryTable);
540 *base = _dispContext.ImageBase;
541 return _dispContext.FunctionEntry;
542 }
543 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()544 int stepWithSEHData() {
545 _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
546 _dispContext.ImageBase,
547 _dispContext.ControlPc,
548 _dispContext.FunctionEntry,
549 _dispContext.ContextRecord,
550 &_dispContext.HandlerData,
551 &_dispContext.EstablisherFrame,
552 NULL);
553 // Update some fields of the unwind info now, since we have them.
554 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
555 if (_dispContext.LanguageHandler) {
556 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
557 } else
558 _info.handler = 0;
559 return UNW_STEP_SUCCESS;
560 }
561
562 A &_addressSpace;
563 unw_proc_info_t _info;
564 DISPATCHER_CONTEXT _dispContext;
565 CONTEXT _msContext;
566 UNWIND_HISTORY_TABLE _histTable;
567 bool _unwindInfoMissing;
568 };
569
570
571 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)572 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
573 : _addressSpace(as), _unwindInfoMissing(false) {
574 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
575 "UnwindCursor<> does not fit in unw_cursor_t");
576 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
577 "UnwindCursor<> requires more alignment than unw_cursor_t");
578 memset(&_info, 0, sizeof(_info));
579 memset(&_histTable, 0, sizeof(_histTable));
580 memset(&_dispContext, 0, sizeof(_dispContext));
581 _dispContext.ContextRecord = &_msContext;
582 _dispContext.HistoryTable = &_histTable;
583 // Initialize MS context from ours.
584 R r(context);
585 RtlCaptureContext(&_msContext);
586 _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
587 #if defined(_LIBUNWIND_TARGET_X86_64)
588 _msContext.Rax = r.getRegister(UNW_X86_64_RAX);
589 _msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
590 _msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
591 _msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
592 _msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
593 _msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
594 _msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
595 _msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
596 _msContext.R8 = r.getRegister(UNW_X86_64_R8);
597 _msContext.R9 = r.getRegister(UNW_X86_64_R9);
598 _msContext.R10 = r.getRegister(UNW_X86_64_R10);
599 _msContext.R11 = r.getRegister(UNW_X86_64_R11);
600 _msContext.R12 = r.getRegister(UNW_X86_64_R12);
601 _msContext.R13 = r.getRegister(UNW_X86_64_R13);
602 _msContext.R14 = r.getRegister(UNW_X86_64_R14);
603 _msContext.R15 = r.getRegister(UNW_X86_64_R15);
604 _msContext.Rip = r.getRegister(UNW_REG_IP);
605 union {
606 v128 v;
607 M128A m;
608 } t;
609 t.v = r.getVectorRegister(UNW_X86_64_XMM0);
610 _msContext.Xmm0 = t.m;
611 t.v = r.getVectorRegister(UNW_X86_64_XMM1);
612 _msContext.Xmm1 = t.m;
613 t.v = r.getVectorRegister(UNW_X86_64_XMM2);
614 _msContext.Xmm2 = t.m;
615 t.v = r.getVectorRegister(UNW_X86_64_XMM3);
616 _msContext.Xmm3 = t.m;
617 t.v = r.getVectorRegister(UNW_X86_64_XMM4);
618 _msContext.Xmm4 = t.m;
619 t.v = r.getVectorRegister(UNW_X86_64_XMM5);
620 _msContext.Xmm5 = t.m;
621 t.v = r.getVectorRegister(UNW_X86_64_XMM6);
622 _msContext.Xmm6 = t.m;
623 t.v = r.getVectorRegister(UNW_X86_64_XMM7);
624 _msContext.Xmm7 = t.m;
625 t.v = r.getVectorRegister(UNW_X86_64_XMM8);
626 _msContext.Xmm8 = t.m;
627 t.v = r.getVectorRegister(UNW_X86_64_XMM9);
628 _msContext.Xmm9 = t.m;
629 t.v = r.getVectorRegister(UNW_X86_64_XMM10);
630 _msContext.Xmm10 = t.m;
631 t.v = r.getVectorRegister(UNW_X86_64_XMM11);
632 _msContext.Xmm11 = t.m;
633 t.v = r.getVectorRegister(UNW_X86_64_XMM12);
634 _msContext.Xmm12 = t.m;
635 t.v = r.getVectorRegister(UNW_X86_64_XMM13);
636 _msContext.Xmm13 = t.m;
637 t.v = r.getVectorRegister(UNW_X86_64_XMM14);
638 _msContext.Xmm14 = t.m;
639 t.v = r.getVectorRegister(UNW_X86_64_XMM15);
640 _msContext.Xmm15 = t.m;
641 #elif defined(_LIBUNWIND_TARGET_ARM)
642 _msContext.R0 = r.getRegister(UNW_ARM_R0);
643 _msContext.R1 = r.getRegister(UNW_ARM_R1);
644 _msContext.R2 = r.getRegister(UNW_ARM_R2);
645 _msContext.R3 = r.getRegister(UNW_ARM_R3);
646 _msContext.R4 = r.getRegister(UNW_ARM_R4);
647 _msContext.R5 = r.getRegister(UNW_ARM_R5);
648 _msContext.R6 = r.getRegister(UNW_ARM_R6);
649 _msContext.R7 = r.getRegister(UNW_ARM_R7);
650 _msContext.R8 = r.getRegister(UNW_ARM_R8);
651 _msContext.R9 = r.getRegister(UNW_ARM_R9);
652 _msContext.R10 = r.getRegister(UNW_ARM_R10);
653 _msContext.R11 = r.getRegister(UNW_ARM_R11);
654 _msContext.R12 = r.getRegister(UNW_ARM_R12);
655 _msContext.Sp = r.getRegister(UNW_ARM_SP);
656 _msContext.Lr = r.getRegister(UNW_ARM_LR);
657 _msContext.Pc = r.getRegister(UNW_ARM_IP);
658 for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
659 union {
660 uint64_t w;
661 double d;
662 } d;
663 d.d = r.getFloatRegister(i);
664 _msContext.D[i - UNW_ARM_D0] = d.w;
665 }
666 #elif defined(_LIBUNWIND_TARGET_AARCH64)
667 for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
668 _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
669 _msContext.Sp = r.getRegister(UNW_REG_SP);
670 _msContext.Pc = r.getRegister(UNW_REG_IP);
671 for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
672 _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
673 #endif
674 }
675
676 template <typename A, typename R>
UnwindCursor(CONTEXT * context,A & as)677 UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
678 : _addressSpace(as), _unwindInfoMissing(false) {
679 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
680 "UnwindCursor<> does not fit in unw_cursor_t");
681 memset(&_info, 0, sizeof(_info));
682 memset(&_histTable, 0, sizeof(_histTable));
683 memset(&_dispContext, 0, sizeof(_dispContext));
684 _dispContext.ContextRecord = &_msContext;
685 _dispContext.HistoryTable = &_histTable;
686 _msContext = *context;
687 }
688
689
690 template <typename A, typename R>
validReg(int regNum)691 bool UnwindCursor<A, R>::validReg(int regNum) {
692 if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
693 #if defined(_LIBUNWIND_TARGET_X86_64)
694 if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_RIP) return true;
695 #elif defined(_LIBUNWIND_TARGET_ARM)
696 if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
697 regNum == UNW_ARM_RA_AUTH_CODE)
698 return true;
699 #elif defined(_LIBUNWIND_TARGET_AARCH64)
700 if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
701 #endif
702 return false;
703 }
704
705 template <typename A, typename R>
getReg(int regNum)706 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
707 switch (regNum) {
708 #if defined(_LIBUNWIND_TARGET_X86_64)
709 case UNW_X86_64_RIP:
710 case UNW_REG_IP: return _msContext.Rip;
711 case UNW_X86_64_RAX: return _msContext.Rax;
712 case UNW_X86_64_RDX: return _msContext.Rdx;
713 case UNW_X86_64_RCX: return _msContext.Rcx;
714 case UNW_X86_64_RBX: return _msContext.Rbx;
715 case UNW_REG_SP:
716 case UNW_X86_64_RSP: return _msContext.Rsp;
717 case UNW_X86_64_RBP: return _msContext.Rbp;
718 case UNW_X86_64_RSI: return _msContext.Rsi;
719 case UNW_X86_64_RDI: return _msContext.Rdi;
720 case UNW_X86_64_R8: return _msContext.R8;
721 case UNW_X86_64_R9: return _msContext.R9;
722 case UNW_X86_64_R10: return _msContext.R10;
723 case UNW_X86_64_R11: return _msContext.R11;
724 case UNW_X86_64_R12: return _msContext.R12;
725 case UNW_X86_64_R13: return _msContext.R13;
726 case UNW_X86_64_R14: return _msContext.R14;
727 case UNW_X86_64_R15: return _msContext.R15;
728 #elif defined(_LIBUNWIND_TARGET_ARM)
729 case UNW_ARM_R0: return _msContext.R0;
730 case UNW_ARM_R1: return _msContext.R1;
731 case UNW_ARM_R2: return _msContext.R2;
732 case UNW_ARM_R3: return _msContext.R3;
733 case UNW_ARM_R4: return _msContext.R4;
734 case UNW_ARM_R5: return _msContext.R5;
735 case UNW_ARM_R6: return _msContext.R6;
736 case UNW_ARM_R7: return _msContext.R7;
737 case UNW_ARM_R8: return _msContext.R8;
738 case UNW_ARM_R9: return _msContext.R9;
739 case UNW_ARM_R10: return _msContext.R10;
740 case UNW_ARM_R11: return _msContext.R11;
741 case UNW_ARM_R12: return _msContext.R12;
742 case UNW_REG_SP:
743 case UNW_ARM_SP: return _msContext.Sp;
744 case UNW_ARM_LR: return _msContext.Lr;
745 case UNW_REG_IP:
746 case UNW_ARM_IP: return _msContext.Pc;
747 #elif defined(_LIBUNWIND_TARGET_AARCH64)
748 case UNW_REG_SP: return _msContext.Sp;
749 case UNW_REG_IP: return _msContext.Pc;
750 default: return _msContext.X[regNum - UNW_AARCH64_X0];
751 #endif
752 }
753 _LIBUNWIND_ABORT("unsupported register");
754 }
755
756 template <typename A, typename R>
setReg(int regNum,unw_word_t value)757 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
758 switch (regNum) {
759 #if defined(_LIBUNWIND_TARGET_X86_64)
760 case UNW_X86_64_RIP:
761 case UNW_REG_IP: _msContext.Rip = value; break;
762 case UNW_X86_64_RAX: _msContext.Rax = value; break;
763 case UNW_X86_64_RDX: _msContext.Rdx = value; break;
764 case UNW_X86_64_RCX: _msContext.Rcx = value; break;
765 case UNW_X86_64_RBX: _msContext.Rbx = value; break;
766 case UNW_REG_SP:
767 case UNW_X86_64_RSP: _msContext.Rsp = value; break;
768 case UNW_X86_64_RBP: _msContext.Rbp = value; break;
769 case UNW_X86_64_RSI: _msContext.Rsi = value; break;
770 case UNW_X86_64_RDI: _msContext.Rdi = value; break;
771 case UNW_X86_64_R8: _msContext.R8 = value; break;
772 case UNW_X86_64_R9: _msContext.R9 = value; break;
773 case UNW_X86_64_R10: _msContext.R10 = value; break;
774 case UNW_X86_64_R11: _msContext.R11 = value; break;
775 case UNW_X86_64_R12: _msContext.R12 = value; break;
776 case UNW_X86_64_R13: _msContext.R13 = value; break;
777 case UNW_X86_64_R14: _msContext.R14 = value; break;
778 case UNW_X86_64_R15: _msContext.R15 = value; break;
779 #elif defined(_LIBUNWIND_TARGET_ARM)
780 case UNW_ARM_R0: _msContext.R0 = value; break;
781 case UNW_ARM_R1: _msContext.R1 = value; break;
782 case UNW_ARM_R2: _msContext.R2 = value; break;
783 case UNW_ARM_R3: _msContext.R3 = value; break;
784 case UNW_ARM_R4: _msContext.R4 = value; break;
785 case UNW_ARM_R5: _msContext.R5 = value; break;
786 case UNW_ARM_R6: _msContext.R6 = value; break;
787 case UNW_ARM_R7: _msContext.R7 = value; break;
788 case UNW_ARM_R8: _msContext.R8 = value; break;
789 case UNW_ARM_R9: _msContext.R9 = value; break;
790 case UNW_ARM_R10: _msContext.R10 = value; break;
791 case UNW_ARM_R11: _msContext.R11 = value; break;
792 case UNW_ARM_R12: _msContext.R12 = value; break;
793 case UNW_REG_SP:
794 case UNW_ARM_SP: _msContext.Sp = value; break;
795 case UNW_ARM_LR: _msContext.Lr = value; break;
796 case UNW_REG_IP:
797 case UNW_ARM_IP: _msContext.Pc = value; break;
798 #elif defined(_LIBUNWIND_TARGET_AARCH64)
799 case UNW_REG_SP: _msContext.Sp = value; break;
800 case UNW_REG_IP: _msContext.Pc = value; break;
801 case UNW_AARCH64_X0:
802 case UNW_AARCH64_X1:
803 case UNW_AARCH64_X2:
804 case UNW_AARCH64_X3:
805 case UNW_AARCH64_X4:
806 case UNW_AARCH64_X5:
807 case UNW_AARCH64_X6:
808 case UNW_AARCH64_X7:
809 case UNW_AARCH64_X8:
810 case UNW_AARCH64_X9:
811 case UNW_AARCH64_X10:
812 case UNW_AARCH64_X11:
813 case UNW_AARCH64_X12:
814 case UNW_AARCH64_X13:
815 case UNW_AARCH64_X14:
816 case UNW_AARCH64_X15:
817 case UNW_AARCH64_X16:
818 case UNW_AARCH64_X17:
819 case UNW_AARCH64_X18:
820 case UNW_AARCH64_X19:
821 case UNW_AARCH64_X20:
822 case UNW_AARCH64_X21:
823 case UNW_AARCH64_X22:
824 case UNW_AARCH64_X23:
825 case UNW_AARCH64_X24:
826 case UNW_AARCH64_X25:
827 case UNW_AARCH64_X26:
828 case UNW_AARCH64_X27:
829 case UNW_AARCH64_X28:
830 case UNW_AARCH64_FP:
831 case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
832 #endif
833 default:
834 _LIBUNWIND_ABORT("unsupported register");
835 }
836 }
837
838 template <typename A, typename R>
validFloatReg(int regNum)839 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
840 #if defined(_LIBUNWIND_TARGET_ARM)
841 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
842 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
843 #elif defined(_LIBUNWIND_TARGET_AARCH64)
844 if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
845 #else
846 (void)regNum;
847 #endif
848 return false;
849 }
850
851 template <typename A, typename R>
getFloatReg(int regNum)852 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
853 #if defined(_LIBUNWIND_TARGET_ARM)
854 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
855 union {
856 uint32_t w;
857 float f;
858 } d;
859 d.w = _msContext.S[regNum - UNW_ARM_S0];
860 return d.f;
861 }
862 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
863 union {
864 uint64_t w;
865 double d;
866 } d;
867 d.w = _msContext.D[regNum - UNW_ARM_D0];
868 return d.d;
869 }
870 _LIBUNWIND_ABORT("unsupported float register");
871 #elif defined(_LIBUNWIND_TARGET_AARCH64)
872 return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
873 #else
874 (void)regNum;
875 _LIBUNWIND_ABORT("float registers unimplemented");
876 #endif
877 }
878
879 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)880 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
881 #if defined(_LIBUNWIND_TARGET_ARM)
882 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
883 union {
884 uint32_t w;
885 float f;
886 } d;
887 d.f = (float)value;
888 _msContext.S[regNum - UNW_ARM_S0] = d.w;
889 }
890 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
891 union {
892 uint64_t w;
893 double d;
894 } d;
895 d.d = value;
896 _msContext.D[regNum - UNW_ARM_D0] = d.w;
897 }
898 _LIBUNWIND_ABORT("unsupported float register");
899 #elif defined(_LIBUNWIND_TARGET_AARCH64)
900 _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
901 #else
902 (void)regNum;
903 (void)value;
904 _LIBUNWIND_ABORT("float registers unimplemented");
905 #endif
906 }
907
jumpto()908 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
909 RtlRestoreContext(&_msContext, nullptr);
910 }
911
912 #ifdef __arm__
saveVFPAsX()913 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
914 #endif
915
916 template <typename A, typename R>
getRegisterName(int regNum)917 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
918 return R::getRegisterName(regNum);
919 }
920
isSignalFrame()921 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
922 return false;
923 }
924
925 #else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
926
927 /// UnwindCursor contains all state (including all register values) during
928 /// an unwind. This is normally stack allocated inside a unw_cursor_t.
929 template <typename A, typename R>
930 class UnwindCursor : public AbstractUnwindCursor{
931 typedef typename A::pint_t pint_t;
932 public:
933 UnwindCursor(unw_context_t *context, A &as);
934 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()935 virtual ~UnwindCursor() {}
936 virtual bool validReg(int);
937 virtual unw_word_t getReg(int);
938 virtual void setReg(int, unw_word_t);
939 virtual bool validFloatReg(int);
940 virtual unw_fpreg_t getFloatReg(int);
941 virtual void setFloatReg(int, unw_fpreg_t);
942 virtual int step(bool stage2 = false);
943 virtual void getInfo(unw_proc_info_t *);
944 virtual void jumpto();
945 virtual bool isSignalFrame();
946 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
947 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
948 virtual const char *getRegisterName(int num);
949 #ifdef __arm__
950 virtual void saveVFPAsX();
951 #endif
952
953 #ifdef _AIX
954 virtual uintptr_t getDataRelBase();
955 #endif
956
957 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
get_registers()958 virtual void *get_registers() { return &_registers; }
959 #endif
960
961 // libunwind does not and should not depend on C++ library which means that we
962 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)963 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
964
965 private:
966
967 #if defined(_LIBUNWIND_ARM_EHABI)
968 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s);
969
stepWithEHABI()970 int stepWithEHABI() {
971 size_t len = 0;
972 size_t off = 0;
973 // FIXME: Calling decode_eht_entry() here is violating the libunwind
974 // abstraction layer.
975 const uint32_t *ehtp =
976 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
977 &off, &len);
978 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
979 _URC_CONTINUE_UNWIND)
980 return UNW_STEP_END;
981 return UNW_STEP_SUCCESS;
982 }
983 #endif
984
985 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
setInfoForSigReturn()986 bool setInfoForSigReturn() {
987 R dummy;
988 return setInfoForSigReturn(dummy);
989 }
stepThroughSigReturn()990 int stepThroughSigReturn() {
991 R dummy;
992 return stepThroughSigReturn(dummy);
993 }
994 bool isReadableAddr(const pint_t addr) const;
995 #if defined(_LIBUNWIND_TARGET_AARCH64)
996 bool setInfoForSigReturn(Registers_arm64 &);
997 int stepThroughSigReturn(Registers_arm64 &);
998 #endif
999 #if defined(_LIBUNWIND_TARGET_RISCV)
1000 bool setInfoForSigReturn(Registers_riscv &);
1001 int stepThroughSigReturn(Registers_riscv &);
1002 #endif
1003 #if defined(_LIBUNWIND_TARGET_S390X)
1004 bool setInfoForSigReturn(Registers_s390x &);
1005 int stepThroughSigReturn(Registers_s390x &);
1006 #endif
setInfoForSigReturn(Registers &)1007 template <typename Registers> bool setInfoForSigReturn(Registers &) {
1008 return false;
1009 }
stepThroughSigReturn(Registers &)1010 template <typename Registers> int stepThroughSigReturn(Registers &) {
1011 return UNW_STEP_END;
1012 }
1013 #endif
1014
1015 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1016 bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1017 const typename CFI_Parser<A>::CIE_Info &cieInfo,
1018 pint_t pc, uintptr_t dso_base);
1019 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s,
1020 uint32_t fdeSectionOffsetHint=0);
stepWithDwarfFDE(bool stage2)1021 int stepWithDwarfFDE(bool stage2) {
1022 return DwarfInstructions<A, R>::stepWithDwarf(
1023 _addressSpace, (pint_t)this->getReg(UNW_REG_IP),
1024 (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2);
1025 }
1026 #endif
1027
1028 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1029 bool getInfoFromCompactEncodingSection(pint_t pc,
1030 const UnwindInfoSections §s);
stepWithCompactEncoding(bool stage2=false)1031 int stepWithCompactEncoding(bool stage2 = false) {
1032 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1033 if ( compactSaysUseDwarf() )
1034 return stepWithDwarfFDE(stage2);
1035 #endif
1036 R dummy;
1037 return stepWithCompactEncoding(dummy);
1038 }
1039
1040 #if defined(_LIBUNWIND_TARGET_X86_64)
stepWithCompactEncoding(Registers_x86_64 &)1041 int stepWithCompactEncoding(Registers_x86_64 &) {
1042 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
1043 _info.format, _info.start_ip, _addressSpace, _registers);
1044 }
1045 #endif
1046
1047 #if defined(_LIBUNWIND_TARGET_I386)
stepWithCompactEncoding(Registers_x86 &)1048 int stepWithCompactEncoding(Registers_x86 &) {
1049 return CompactUnwinder_x86<A>::stepWithCompactEncoding(
1050 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
1051 }
1052 #endif
1053
1054 #if defined(_LIBUNWIND_TARGET_PPC)
stepWithCompactEncoding(Registers_ppc &)1055 int stepWithCompactEncoding(Registers_ppc &) {
1056 return UNW_EINVAL;
1057 }
1058 #endif
1059
1060 #if defined(_LIBUNWIND_TARGET_PPC64)
stepWithCompactEncoding(Registers_ppc64 &)1061 int stepWithCompactEncoding(Registers_ppc64 &) {
1062 return UNW_EINVAL;
1063 }
1064 #endif
1065
1066
1067 #if defined(_LIBUNWIND_TARGET_AARCH64)
stepWithCompactEncoding(Registers_arm64 &)1068 int stepWithCompactEncoding(Registers_arm64 &) {
1069 return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
1070 _info.format, _info.start_ip, _addressSpace, _registers);
1071 }
1072 #endif
1073
1074 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
stepWithCompactEncoding(Registers_mips_o32 &)1075 int stepWithCompactEncoding(Registers_mips_o32 &) {
1076 return UNW_EINVAL;
1077 }
1078 #endif
1079
1080 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
stepWithCompactEncoding(Registers_mips_newabi &)1081 int stepWithCompactEncoding(Registers_mips_newabi &) {
1082 return UNW_EINVAL;
1083 }
1084 #endif
1085
1086 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
stepWithCompactEncoding(Registers_loongarch &)1087 int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; }
1088 #endif
1089
1090 #if defined(_LIBUNWIND_TARGET_SPARC)
stepWithCompactEncoding(Registers_sparc &)1091 int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
1092 #endif
1093
1094 #if defined(_LIBUNWIND_TARGET_SPARC64)
stepWithCompactEncoding(Registers_sparc64 &)1095 int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
1096 #endif
1097
1098 #if defined (_LIBUNWIND_TARGET_RISCV)
stepWithCompactEncoding(Registers_riscv &)1099 int stepWithCompactEncoding(Registers_riscv &) {
1100 return UNW_EINVAL;
1101 }
1102 #endif
1103
compactSaysUseDwarf(uint32_t * offset=NULL) const1104 bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
1105 R dummy;
1106 return compactSaysUseDwarf(dummy, offset);
1107 }
1108
1109 #if defined(_LIBUNWIND_TARGET_X86_64)
compactSaysUseDwarf(Registers_x86_64 &,uint32_t * offset) const1110 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
1111 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
1112 if (offset)
1113 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
1114 return true;
1115 }
1116 return false;
1117 }
1118 #endif
1119
1120 #if defined(_LIBUNWIND_TARGET_I386)
compactSaysUseDwarf(Registers_x86 &,uint32_t * offset) const1121 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
1122 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
1123 if (offset)
1124 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
1125 return true;
1126 }
1127 return false;
1128 }
1129 #endif
1130
1131 #if defined(_LIBUNWIND_TARGET_PPC)
compactSaysUseDwarf(Registers_ppc &,uint32_t *) const1132 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
1133 return true;
1134 }
1135 #endif
1136
1137 #if defined(_LIBUNWIND_TARGET_PPC64)
compactSaysUseDwarf(Registers_ppc64 &,uint32_t *) const1138 bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
1139 return true;
1140 }
1141 #endif
1142
1143 #if defined(_LIBUNWIND_TARGET_AARCH64)
compactSaysUseDwarf(Registers_arm64 &,uint32_t * offset) const1144 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
1145 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
1146 if (offset)
1147 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
1148 return true;
1149 }
1150 return false;
1151 }
1152 #endif
1153
1154 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
compactSaysUseDwarf(Registers_mips_o32 &,uint32_t *) const1155 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
1156 return true;
1157 }
1158 #endif
1159
1160 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
compactSaysUseDwarf(Registers_mips_newabi &,uint32_t *) const1161 bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
1162 return true;
1163 }
1164 #endif
1165
1166 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
compactSaysUseDwarf(Registers_loongarch &,uint32_t *) const1167 bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const {
1168 return true;
1169 }
1170 #endif
1171
1172 #if defined(_LIBUNWIND_TARGET_SPARC)
compactSaysUseDwarf(Registers_sparc &,uint32_t *) const1173 bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
1174 #endif
1175
1176 #if defined(_LIBUNWIND_TARGET_SPARC64)
compactSaysUseDwarf(Registers_sparc64 &,uint32_t *) const1177 bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
1178 return true;
1179 }
1180 #endif
1181
1182 #if defined (_LIBUNWIND_TARGET_RISCV)
compactSaysUseDwarf(Registers_riscv &,uint32_t *) const1183 bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
1184 return true;
1185 }
1186 #endif
1187
1188 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1189
1190 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
dwarfEncoding() const1191 compact_unwind_encoding_t dwarfEncoding() const {
1192 R dummy;
1193 return dwarfEncoding(dummy);
1194 }
1195
1196 #if defined(_LIBUNWIND_TARGET_X86_64)
dwarfEncoding(Registers_x86_64 &) const1197 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
1198 return UNWIND_X86_64_MODE_DWARF;
1199 }
1200 #endif
1201
1202 #if defined(_LIBUNWIND_TARGET_I386)
dwarfEncoding(Registers_x86 &) const1203 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
1204 return UNWIND_X86_MODE_DWARF;
1205 }
1206 #endif
1207
1208 #if defined(_LIBUNWIND_TARGET_PPC)
dwarfEncoding(Registers_ppc &) const1209 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
1210 return 0;
1211 }
1212 #endif
1213
1214 #if defined(_LIBUNWIND_TARGET_PPC64)
dwarfEncoding(Registers_ppc64 &) const1215 compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
1216 return 0;
1217 }
1218 #endif
1219
1220 #if defined(_LIBUNWIND_TARGET_AARCH64)
dwarfEncoding(Registers_arm64 &) const1221 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
1222 return UNWIND_ARM64_MODE_DWARF;
1223 }
1224 #endif
1225
1226 #if defined(_LIBUNWIND_TARGET_ARM)
dwarfEncoding(Registers_arm &) const1227 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
1228 return 0;
1229 }
1230 #endif
1231
1232 #if defined (_LIBUNWIND_TARGET_OR1K)
dwarfEncoding(Registers_or1k &) const1233 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
1234 return 0;
1235 }
1236 #endif
1237
1238 #if defined (_LIBUNWIND_TARGET_HEXAGON)
dwarfEncoding(Registers_hexagon &) const1239 compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
1240 return 0;
1241 }
1242 #endif
1243
1244 #if defined (_LIBUNWIND_TARGET_MIPS_O32)
dwarfEncoding(Registers_mips_o32 &) const1245 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
1246 return 0;
1247 }
1248 #endif
1249
1250 #if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
dwarfEncoding(Registers_mips_newabi &) const1251 compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
1252 return 0;
1253 }
1254 #endif
1255
1256 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
dwarfEncoding(Registers_loongarch &) const1257 compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const {
1258 return 0;
1259 }
1260 #endif
1261
1262 #if defined(_LIBUNWIND_TARGET_SPARC)
dwarfEncoding(Registers_sparc &) const1263 compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
1264 #endif
1265
1266 #if defined(_LIBUNWIND_TARGET_SPARC64)
dwarfEncoding(Registers_sparc64 &) const1267 compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
1268 return 0;
1269 }
1270 #endif
1271
1272 #if defined (_LIBUNWIND_TARGET_RISCV)
dwarfEncoding(Registers_riscv &) const1273 compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
1274 return 0;
1275 }
1276 #endif
1277
1278 #if defined (_LIBUNWIND_TARGET_S390X)
dwarfEncoding(Registers_s390x &) const1279 compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const {
1280 return 0;
1281 }
1282 #endif
1283
1284 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1285
1286 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1287 // For runtime environments using SEH unwind data without Windows runtime
1288 // support.
getLastPC() const1289 pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
setLastPC(pint_t pc)1290 void setLastPC(pint_t pc) { /* FIXME: Implement */ }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)1291 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
1292 /* FIXME: Implement */
1293 *base = 0;
1294 return nullptr;
1295 }
1296 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()1297 int stepWithSEHData() { /* FIXME: Implement */ return 0; }
1298 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1299
1300 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1301 bool getInfoFromTBTable(pint_t pc, R ®isters);
1302 int stepWithTBTable(pint_t pc, tbtable *TBTable, R ®isters,
1303 bool &isSignalFrame);
stepWithTBTableData()1304 int stepWithTBTableData() {
1305 return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
1306 reinterpret_cast<tbtable *>(_info.unwind_info),
1307 _registers, _isSignalFrame);
1308 }
1309 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1310
1311 A &_addressSpace;
1312 R _registers;
1313 unw_proc_info_t _info;
1314 bool _unwindInfoMissing;
1315 bool _isSignalFrame;
1316 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
1317 bool _isSigReturn = false;
1318 #endif
1319 };
1320
1321
1322 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)1323 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
1324 : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
1325 _isSignalFrame(false) {
1326 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
1327 "UnwindCursor<> does not fit in unw_cursor_t");
1328 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
1329 "UnwindCursor<> requires more alignment than unw_cursor_t");
1330 memset(&_info, 0, sizeof(_info));
1331 }
1332
1333 template <typename A, typename R>
UnwindCursor(A & as,void *)1334 UnwindCursor<A, R>::UnwindCursor(A &as, void *)
1335 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
1336 memset(&_info, 0, sizeof(_info));
1337 // FIXME
1338 // fill in _registers from thread arg
1339 }
1340
1341
1342 template <typename A, typename R>
validReg(int regNum)1343 bool UnwindCursor<A, R>::validReg(int regNum) {
1344 return _registers.validRegister(regNum);
1345 }
1346
1347 template <typename A, typename R>
getReg(int regNum)1348 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
1349 return _registers.getRegister(regNum);
1350 }
1351
1352 template <typename A, typename R>
setReg(int regNum,unw_word_t value)1353 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
1354 _registers.setRegister(regNum, (typename A::pint_t)value);
1355 }
1356
1357 template <typename A, typename R>
validFloatReg(int regNum)1358 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
1359 return _registers.validFloatRegister(regNum);
1360 }
1361
1362 template <typename A, typename R>
getFloatReg(int regNum)1363 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
1364 return _registers.getFloatRegister(regNum);
1365 }
1366
1367 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)1368 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
1369 _registers.setFloatRegister(regNum, value);
1370 }
1371
jumpto()1372 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
1373 _registers.jumpto();
1374 }
1375
1376 #ifdef __arm__
saveVFPAsX()1377 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
1378 _registers.saveVFPAsX();
1379 }
1380 #endif
1381
1382 #ifdef _AIX
1383 template <typename A, typename R>
getDataRelBase()1384 uintptr_t UnwindCursor<A, R>::getDataRelBase() {
1385 return reinterpret_cast<uintptr_t>(_info.extra);
1386 }
1387 #endif
1388
1389 template <typename A, typename R>
getRegisterName(int regNum)1390 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
1391 return _registers.getRegisterName(regNum);
1392 }
1393
isSignalFrame()1394 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
1395 return _isSignalFrame;
1396 }
1397
1398 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1399
1400 #if defined(_LIBUNWIND_ARM_EHABI)
1401 template<typename A>
1402 struct EHABISectionIterator {
1403 typedef EHABISectionIterator _Self;
1404
1405 typedef typename A::pint_t value_type;
1406 typedef typename A::pint_t* pointer;
1407 typedef typename A::pint_t& reference;
1408 typedef size_t size_type;
1409 typedef size_t difference_type;
1410
beginlibunwind::EHABISectionIterator1411 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
1412 return _Self(addressSpace, sects, 0);
1413 }
endlibunwind::EHABISectionIterator1414 static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
1415 return _Self(addressSpace, sects,
1416 sects.arm_section_length / sizeof(EHABIIndexEntry));
1417 }
1418
EHABISectionIteratorlibunwind::EHABISectionIterator1419 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
1420 : _i(i), _addressSpace(&addressSpace), _sects(§s) {}
1421
operator ++libunwind::EHABISectionIterator1422 _Self& operator++() { ++_i; return *this; }
operator +=libunwind::EHABISectionIterator1423 _Self& operator+=(size_t a) { _i += a; return *this; }
operator --libunwind::EHABISectionIterator1424 _Self& operator--() { assert(_i > 0); --_i; return *this; }
operator -=libunwind::EHABISectionIterator1425 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
1426
operator +libunwind::EHABISectionIterator1427 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
operator -libunwind::EHABISectionIterator1428 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
1429
operator -libunwind::EHABISectionIterator1430 size_t operator-(const _Self& other) const { return _i - other._i; }
1431
operator ==libunwind::EHABISectionIterator1432 bool operator==(const _Self& other) const {
1433 assert(_addressSpace == other._addressSpace);
1434 assert(_sects == other._sects);
1435 return _i == other._i;
1436 }
1437
operator !=libunwind::EHABISectionIterator1438 bool operator!=(const _Self& other) const {
1439 assert(_addressSpace == other._addressSpace);
1440 assert(_sects == other._sects);
1441 return _i != other._i;
1442 }
1443
operator *libunwind::EHABISectionIterator1444 typename A::pint_t operator*() const { return functionAddress(); }
1445
functionAddresslibunwind::EHABISectionIterator1446 typename A::pint_t functionAddress() const {
1447 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1448 EHABIIndexEntry, _i, functionOffset);
1449 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
1450 }
1451
dataAddresslibunwind::EHABISectionIterator1452 typename A::pint_t dataAddress() {
1453 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1454 EHABIIndexEntry, _i, data);
1455 return indexAddr;
1456 }
1457
1458 private:
1459 size_t _i;
1460 A* _addressSpace;
1461 const UnwindInfoSections* _sects;
1462 };
1463
1464 namespace {
1465
1466 template <typename A>
EHABISectionUpperBound(EHABISectionIterator<A> first,EHABISectionIterator<A> last,typename A::pint_t value)1467 EHABISectionIterator<A> EHABISectionUpperBound(
1468 EHABISectionIterator<A> first,
1469 EHABISectionIterator<A> last,
1470 typename A::pint_t value) {
1471 size_t len = last - first;
1472 while (len > 0) {
1473 size_t l2 = len / 2;
1474 EHABISectionIterator<A> m = first + l2;
1475 if (value < *m) {
1476 len = l2;
1477 } else {
1478 first = ++m;
1479 len -= l2 + 1;
1480 }
1481 }
1482 return first;
1483 }
1484
1485 }
1486
1487 template <typename A, typename R>
getInfoFromEHABISection(pint_t pc,const UnwindInfoSections & sects)1488 bool UnwindCursor<A, R>::getInfoFromEHABISection(
1489 pint_t pc,
1490 const UnwindInfoSections §s) {
1491 EHABISectionIterator<A> begin =
1492 EHABISectionIterator<A>::begin(_addressSpace, sects);
1493 EHABISectionIterator<A> end =
1494 EHABISectionIterator<A>::end(_addressSpace, sects);
1495 if (begin == end)
1496 return false;
1497
1498 EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
1499 if (itNextPC == begin)
1500 return false;
1501 EHABISectionIterator<A> itThisPC = itNextPC - 1;
1502
1503 pint_t thisPC = itThisPC.functionAddress();
1504 // If an exception is thrown from a function, corresponding to the last entry
1505 // in the table, we don't really know the function extent and have to choose a
1506 // value for nextPC. Choosing max() will allow the range check during trace to
1507 // succeed.
1508 pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
1509 pint_t indexDataAddr = itThisPC.dataAddress();
1510
1511 if (indexDataAddr == 0)
1512 return false;
1513
1514 uint32_t indexData = _addressSpace.get32(indexDataAddr);
1515 if (indexData == UNW_EXIDX_CANTUNWIND)
1516 return false;
1517
1518 // If the high bit is set, the exception handling table entry is inline inside
1519 // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
1520 // the table points at an offset in the exception handling table (section 5
1521 // EHABI).
1522 pint_t exceptionTableAddr;
1523 uint32_t exceptionTableData;
1524 bool isSingleWordEHT;
1525 if (indexData & 0x80000000) {
1526 exceptionTableAddr = indexDataAddr;
1527 // TODO(ajwong): Should this data be 0?
1528 exceptionTableData = indexData;
1529 isSingleWordEHT = true;
1530 } else {
1531 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
1532 exceptionTableData = _addressSpace.get32(exceptionTableAddr);
1533 isSingleWordEHT = false;
1534 }
1535
1536 // Now we know the 3 things:
1537 // exceptionTableAddr -- exception handler table entry.
1538 // exceptionTableData -- the data inside the first word of the eht entry.
1539 // isSingleWordEHT -- whether the entry is in the index.
1540 unw_word_t personalityRoutine = 0xbadf00d;
1541 bool scope32 = false;
1542 uintptr_t lsda;
1543
1544 // If the high bit in the exception handling table entry is set, the entry is
1545 // in compact form (section 6.3 EHABI).
1546 if (exceptionTableData & 0x80000000) {
1547 // Grab the index of the personality routine from the compact form.
1548 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
1549 uint32_t extraWords = 0;
1550 switch (choice) {
1551 case 0:
1552 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
1553 extraWords = 0;
1554 scope32 = false;
1555 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
1556 break;
1557 case 1:
1558 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
1559 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1560 scope32 = false;
1561 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1562 break;
1563 case 2:
1564 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
1565 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1566 scope32 = true;
1567 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1568 break;
1569 default:
1570 _LIBUNWIND_ABORT("unknown personality routine");
1571 return false;
1572 }
1573
1574 if (isSingleWordEHT) {
1575 if (extraWords != 0) {
1576 _LIBUNWIND_ABORT("index inlined table detected but pr function "
1577 "requires extra words");
1578 return false;
1579 }
1580 }
1581 } else {
1582 pint_t personalityAddr =
1583 exceptionTableAddr + signExtendPrel31(exceptionTableData);
1584 personalityRoutine = personalityAddr;
1585
1586 // ARM EHABI # 6.2, # 9.2
1587 //
1588 // +---- ehtp
1589 // v
1590 // +--------------------------------------+
1591 // | +--------+--------+--------+-------+ |
1592 // | |0| prel31 to personalityRoutine | |
1593 // | +--------+--------+--------+-------+ |
1594 // | | N | unwind opcodes | | <-- UnwindData
1595 // | +--------+--------+--------+-------+ |
1596 // | | Word 2 unwind opcodes | |
1597 // | +--------+--------+--------+-------+ |
1598 // | ... |
1599 // | +--------+--------+--------+-------+ |
1600 // | | Word N unwind opcodes | |
1601 // | +--------+--------+--------+-------+ |
1602 // | | LSDA | | <-- lsda
1603 // | | ... | |
1604 // | +--------+--------+--------+-------+ |
1605 // +--------------------------------------+
1606
1607 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
1608 uint32_t FirstDataWord = *UnwindData;
1609 size_t N = ((FirstDataWord >> 24) & 0xff);
1610 size_t NDataWords = N + 1;
1611 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
1612 }
1613
1614 _info.start_ip = thisPC;
1615 _info.end_ip = nextPC;
1616 _info.handler = personalityRoutine;
1617 _info.unwind_info = exceptionTableAddr;
1618 _info.lsda = lsda;
1619 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
1620 _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum?
1621
1622 return true;
1623 }
1624 #endif
1625
1626 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1627 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)1628 bool UnwindCursor<A, R>::getInfoFromFdeCie(
1629 const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1630 const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc,
1631 uintptr_t dso_base) {
1632 typename CFI_Parser<A>::PrologInfo prolog;
1633 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
1634 R::getArch(), &prolog)) {
1635 // Save off parsed FDE info
1636 _info.start_ip = fdeInfo.pcStart;
1637 _info.end_ip = fdeInfo.pcEnd;
1638 _info.lsda = fdeInfo.lsda;
1639 _info.handler = cieInfo.personality;
1640 // Some frameless functions need SP altered when resuming in function, so
1641 // propagate spExtraArgSize.
1642 _info.gp = prolog.spExtraArgSize;
1643 _info.flags = 0;
1644 _info.format = dwarfEncoding();
1645 _info.unwind_info = fdeInfo.fdeStart;
1646 _info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength);
1647 _info.extra = static_cast<unw_word_t>(dso_base);
1648 return true;
1649 }
1650 return false;
1651 }
1652
1653 template <typename A, typename R>
getInfoFromDwarfSection(pint_t pc,const UnwindInfoSections & sects,uint32_t fdeSectionOffsetHint)1654 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
1655 const UnwindInfoSections §s,
1656 uint32_t fdeSectionOffsetHint) {
1657 typename CFI_Parser<A>::FDE_Info fdeInfo;
1658 typename CFI_Parser<A>::CIE_Info cieInfo;
1659 bool foundFDE = false;
1660 bool foundInCache = false;
1661 // If compact encoding table gave offset into dwarf section, go directly there
1662 if (fdeSectionOffsetHint != 0) {
1663 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1664 sects.dwarf_section_length,
1665 sects.dwarf_section + fdeSectionOffsetHint,
1666 &fdeInfo, &cieInfo);
1667 }
1668 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1669 if (!foundFDE && (sects.dwarf_index_section != 0)) {
1670 foundFDE = EHHeaderParser<A>::findFDE(
1671 _addressSpace, pc, sects.dwarf_index_section,
1672 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
1673 }
1674 #endif
1675 if (!foundFDE) {
1676 // otherwise, search cache of previously found FDEs.
1677 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
1678 if (cachedFDE != 0) {
1679 foundFDE =
1680 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1681 sects.dwarf_section_length,
1682 cachedFDE, &fdeInfo, &cieInfo);
1683 foundInCache = foundFDE;
1684 }
1685 }
1686 if (!foundFDE) {
1687 // Still not found, do full scan of __eh_frame section.
1688 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1689 sects.dwarf_section_length, 0,
1690 &fdeInfo, &cieInfo);
1691 }
1692 if (foundFDE) {
1693 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) {
1694 // Add to cache (to make next lookup faster) if we had no hint
1695 // and there was no index.
1696 if (!foundInCache && (fdeSectionOffsetHint == 0)) {
1697 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1698 if (sects.dwarf_index_section == 0)
1699 #endif
1700 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
1701 fdeInfo.fdeStart);
1702 }
1703 return true;
1704 }
1705 }
1706 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
1707 return false;
1708 }
1709 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1710
1711
1712 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1713 template <typename A, typename R>
getInfoFromCompactEncodingSection(pint_t pc,const UnwindInfoSections & sects)1714 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
1715 const UnwindInfoSections §s) {
1716 const bool log = false;
1717 if (log)
1718 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
1719 (uint64_t)pc, (uint64_t)sects.dso_base);
1720
1721 const UnwindSectionHeader<A> sectionHeader(_addressSpace,
1722 sects.compact_unwind_section);
1723 if (sectionHeader.version() != UNWIND_SECTION_VERSION)
1724 return false;
1725
1726 // do a binary search of top level index to find page with unwind info
1727 pint_t targetFunctionOffset = pc - sects.dso_base;
1728 const UnwindSectionIndexArray<A> topIndex(_addressSpace,
1729 sects.compact_unwind_section
1730 + sectionHeader.indexSectionOffset());
1731 uint32_t low = 0;
1732 uint32_t high = sectionHeader.indexCount();
1733 uint32_t last = high - 1;
1734 while (low < high) {
1735 uint32_t mid = (low + high) / 2;
1736 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
1737 //mid, low, high, topIndex.functionOffset(mid));
1738 if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
1739 if ((mid == last) ||
1740 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
1741 low = mid;
1742 break;
1743 } else {
1744 low = mid + 1;
1745 }
1746 } else {
1747 high = mid;
1748 }
1749 }
1750 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
1751 const uint32_t firstLevelNextPageFunctionOffset =
1752 topIndex.functionOffset(low + 1);
1753 const pint_t secondLevelAddr =
1754 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
1755 const pint_t lsdaArrayStartAddr =
1756 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
1757 const pint_t lsdaArrayEndAddr =
1758 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
1759 if (log)
1760 fprintf(stderr, "\tfirst level search for result index=%d "
1761 "to secondLevelAddr=0x%llX\n",
1762 low, (uint64_t) secondLevelAddr);
1763 // do a binary search of second level page index
1764 uint32_t encoding = 0;
1765 pint_t funcStart = 0;
1766 pint_t funcEnd = 0;
1767 pint_t lsda = 0;
1768 pint_t personality = 0;
1769 uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
1770 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
1771 // regular page
1772 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
1773 secondLevelAddr);
1774 UnwindSectionRegularArray<A> pageIndex(
1775 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1776 // binary search looks for entry with e where index[e].offset <= pc <
1777 // index[e+1].offset
1778 if (log)
1779 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
1780 "regular page starting at secondLevelAddr=0x%llX\n",
1781 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
1782 low = 0;
1783 high = pageHeader.entryCount();
1784 while (low < high) {
1785 uint32_t mid = (low + high) / 2;
1786 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
1787 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
1788 // at end of table
1789 low = mid;
1790 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1791 break;
1792 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
1793 // next is too big, so we found it
1794 low = mid;
1795 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
1796 break;
1797 } else {
1798 low = mid + 1;
1799 }
1800 } else {
1801 high = mid;
1802 }
1803 }
1804 encoding = pageIndex.encoding(low);
1805 funcStart = pageIndex.functionOffset(low) + sects.dso_base;
1806 if (pc < funcStart) {
1807 if (log)
1808 fprintf(
1809 stderr,
1810 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1811 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1812 return false;
1813 }
1814 if (pc > funcEnd) {
1815 if (log)
1816 fprintf(
1817 stderr,
1818 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1819 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1820 return false;
1821 }
1822 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
1823 // compressed page
1824 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
1825 secondLevelAddr);
1826 UnwindSectionCompressedArray<A> pageIndex(
1827 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1828 const uint32_t targetFunctionPageOffset =
1829 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
1830 // binary search looks for entry with e where index[e].offset <= pc <
1831 // index[e+1].offset
1832 if (log)
1833 fprintf(stderr, "\tbinary search of compressed page starting at "
1834 "secondLevelAddr=0x%llX\n",
1835 (uint64_t) secondLevelAddr);
1836 low = 0;
1837 last = pageHeader.entryCount() - 1;
1838 high = pageHeader.entryCount();
1839 while (low < high) {
1840 uint32_t mid = (low + high) / 2;
1841 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
1842 if ((mid == last) ||
1843 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
1844 low = mid;
1845 break;
1846 } else {
1847 low = mid + 1;
1848 }
1849 } else {
1850 high = mid;
1851 }
1852 }
1853 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
1854 + sects.dso_base;
1855 if (low < last)
1856 funcEnd =
1857 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
1858 + sects.dso_base;
1859 else
1860 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1861 if (pc < funcStart) {
1862 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1863 "not in second level compressed unwind table. "
1864 "funcStart=0x%llX",
1865 (uint64_t) pc, (uint64_t) funcStart);
1866 return false;
1867 }
1868 if (pc > funcEnd) {
1869 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1870 "not in second level compressed unwind table. "
1871 "funcEnd=0x%llX",
1872 (uint64_t) pc, (uint64_t) funcEnd);
1873 return false;
1874 }
1875 uint16_t encodingIndex = pageIndex.encodingIndex(low);
1876 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
1877 // encoding is in common table in section header
1878 encoding = _addressSpace.get32(
1879 sects.compact_unwind_section +
1880 sectionHeader.commonEncodingsArraySectionOffset() +
1881 encodingIndex * sizeof(uint32_t));
1882 } else {
1883 // encoding is in page specific table
1884 uint16_t pageEncodingIndex =
1885 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
1886 encoding = _addressSpace.get32(secondLevelAddr +
1887 pageHeader.encodingsPageOffset() +
1888 pageEncodingIndex * sizeof(uint32_t));
1889 }
1890 } else {
1891 _LIBUNWIND_DEBUG_LOG(
1892 "malformed __unwind_info at 0x%0llX bad second level page",
1893 (uint64_t)sects.compact_unwind_section);
1894 return false;
1895 }
1896
1897 // look up LSDA, if encoding says function has one
1898 if (encoding & UNWIND_HAS_LSDA) {
1899 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
1900 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
1901 low = 0;
1902 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
1903 sizeof(unwind_info_section_header_lsda_index_entry);
1904 // binary search looks for entry with exact match for functionOffset
1905 if (log)
1906 fprintf(stderr,
1907 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
1908 funcStartOffset);
1909 while (low < high) {
1910 uint32_t mid = (low + high) / 2;
1911 if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
1912 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
1913 break;
1914 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
1915 low = mid + 1;
1916 } else {
1917 high = mid;
1918 }
1919 }
1920 if (lsda == 0) {
1921 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
1922 "pc=0x%0llX, but lsda table has no entry",
1923 encoding, (uint64_t) pc);
1924 return false;
1925 }
1926 }
1927
1928 // extract personality routine, if encoding says function has one
1929 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
1930 (__builtin_ctz(UNWIND_PERSONALITY_MASK));
1931 if (personalityIndex != 0) {
1932 --personalityIndex; // change 1-based to zero-based index
1933 if (personalityIndex >= sectionHeader.personalityArrayCount()) {
1934 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
1935 "but personality table has only %d entries",
1936 encoding, personalityIndex,
1937 sectionHeader.personalityArrayCount());
1938 return false;
1939 }
1940 int32_t personalityDelta = (int32_t)_addressSpace.get32(
1941 sects.compact_unwind_section +
1942 sectionHeader.personalityArraySectionOffset() +
1943 personalityIndex * sizeof(uint32_t));
1944 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
1945 personality = _addressSpace.getP(personalityPointer);
1946 if (log)
1947 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1948 "personalityDelta=0x%08X, personality=0x%08llX\n",
1949 (uint64_t) pc, personalityDelta, (uint64_t) personality);
1950 }
1951
1952 if (log)
1953 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1954 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
1955 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
1956 _info.start_ip = funcStart;
1957 _info.end_ip = funcEnd;
1958 _info.lsda = lsda;
1959 _info.handler = personality;
1960 _info.gp = 0;
1961 _info.flags = 0;
1962 _info.format = encoding;
1963 _info.unwind_info = 0;
1964 _info.unwind_info_size = 0;
1965 _info.extra = sects.dso_base;
1966 return true;
1967 }
1968 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1969
1970
1971 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1972 template <typename A, typename R>
getInfoFromSEH(pint_t pc)1973 bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
1974 pint_t base;
1975 RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
1976 if (!unwindEntry) {
1977 _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
1978 return false;
1979 }
1980 _info.gp = 0;
1981 _info.flags = 0;
1982 _info.format = 0;
1983 _info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
1984 _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
1985 _info.extra = base;
1986 _info.start_ip = base + unwindEntry->BeginAddress;
1987 #ifdef _LIBUNWIND_TARGET_X86_64
1988 _info.end_ip = base + unwindEntry->EndAddress;
1989 // Only fill in the handler and LSDA if they're stale.
1990 if (pc != getLastPC()) {
1991 UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
1992 if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
1993 // The personality is given in the UNWIND_INFO itself. The LSDA immediately
1994 // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
1995 // these structures.)
1996 // N.B. UNWIND_INFO structs are DWORD-aligned.
1997 uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
1998 const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
1999 _info.lsda = reinterpret_cast<unw_word_t>(handler+1);
2000 _dispContext.HandlerData = reinterpret_cast<void *>(_info.lsda);
2001 _dispContext.LanguageHandler =
2002 reinterpret_cast<EXCEPTION_ROUTINE *>(base + *handler);
2003 if (*handler) {
2004 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2005 } else
2006 _info.handler = 0;
2007 } else {
2008 _info.lsda = 0;
2009 _info.handler = 0;
2010 }
2011 }
2012 #endif
2013 setLastPC(pc);
2014 return true;
2015 }
2016 #endif
2017
2018 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2019 // Masks for traceback table field xtbtable.
2020 enum xTBTableMask : uint8_t {
2021 reservedBit = 0x02, // The traceback table was incorrectly generated if set
2022 // (see comments in function getInfoFromTBTable().
2023 ehInfoBit = 0x08 // Exception handling info is present if set
2024 };
2025
2026 enum frameType : unw_word_t {
2027 frameWithXLEHStateTable = 0,
2028 frameWithEHInfo = 1
2029 };
2030
2031 extern "C" {
2032 typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
2033 uint64_t,
2034 _Unwind_Exception *,
2035 struct _Unwind_Context *);
2036 __attribute__((__weak__)) __xlcxx_personality_v0_t __xlcxx_personality_v0;
2037 }
2038
2039 static __xlcxx_personality_v0_t *xlcPersonalityV0;
2040 static RWMutex xlcPersonalityV0InitLock;
2041
2042 template <typename A, typename R>
getInfoFromTBTable(pint_t pc,R & registers)2043 bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R ®isters) {
2044 uint32_t *p = reinterpret_cast<uint32_t *>(pc);
2045
2046 // Keep looking forward until a word of 0 is found. The traceback
2047 // table starts at the following word.
2048 while (*p)
2049 ++p;
2050 tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
2051
2052 if (_LIBUNWIND_TRACING_UNWINDING) {
2053 char functionBuf[512];
2054 const char *functionName = functionBuf;
2055 unw_word_t offset;
2056 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2057 functionName = ".anonymous.";
2058 }
2059 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2060 __func__, functionName,
2061 reinterpret_cast<void *>(TBTable));
2062 }
2063
2064 // If the traceback table does not contain necessary info, bypass this frame.
2065 if (!TBTable->tb.has_tboff)
2066 return false;
2067
2068 // Structure tbtable_ext contains important data we are looking for.
2069 p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2070
2071 // Skip field parminfo if it exists.
2072 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2073 ++p;
2074
2075 // p now points to tb_offset, the offset from start of function to TB table.
2076 unw_word_t start_ip =
2077 reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
2078 unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
2079 ++p;
2080
2081 _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
2082 reinterpret_cast<void *>(start_ip),
2083 reinterpret_cast<void *>(end_ip));
2084
2085 // Skip field hand_mask if it exists.
2086 if (TBTable->tb.int_hndl)
2087 ++p;
2088
2089 unw_word_t lsda = 0;
2090 unw_word_t handler = 0;
2091 unw_word_t flags = frameType::frameWithXLEHStateTable;
2092
2093 if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
2094 // State table info is available. The ctl_info field indicates the
2095 // number of CTL anchors. There should be only one entry for the C++
2096 // state table.
2097 assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
2098 ++p;
2099 // p points to the offset of the state table into the stack.
2100 pint_t stateTableOffset = *p++;
2101
2102 int framePointerReg;
2103
2104 // Skip fields name_len and name if exist.
2105 if (TBTable->tb.name_present) {
2106 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
2107 p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
2108 sizeof(uint16_t));
2109 }
2110
2111 if (TBTable->tb.uses_alloca)
2112 framePointerReg = *(reinterpret_cast<char *>(p));
2113 else
2114 framePointerReg = 1; // default frame pointer == SP
2115
2116 _LIBUNWIND_TRACE_UNWINDING(
2117 "framePointerReg=%d, framePointer=%p, "
2118 "stateTableOffset=%#lx\n",
2119 framePointerReg,
2120 reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
2121 stateTableOffset);
2122 lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
2123
2124 // Since the traceback table generated by the legacy XLC++ does not
2125 // provide the location of the personality for the state table,
2126 // function __xlcxx_personality_v0(), which is the personality for the state
2127 // table and is exported from libc++abi, is directly assigned as the
2128 // handler here. When a legacy XLC++ frame is encountered, the symbol
2129 // is resolved dynamically using dlopen() to avoid hard dependency from
2130 // libunwind on libc++abi.
2131
2132 // Resolve the function pointer to the state table personality if it has
2133 // not already.
2134 if (xlcPersonalityV0 == NULL) {
2135 xlcPersonalityV0InitLock.lock();
2136 if (xlcPersonalityV0 == NULL) {
2137 // If libc++abi is statically linked in, symbol __xlcxx_personality_v0
2138 // has been resolved at the link time.
2139 xlcPersonalityV0 = &__xlcxx_personality_v0;
2140 if (xlcPersonalityV0 == NULL) {
2141 // libc++abi is dynamically linked. Resolve __xlcxx_personality_v0
2142 // using dlopen().
2143 const char libcxxabi[] = "libc++abi.a(libc++abi.so.1)";
2144 void *libHandle;
2145 // The AIX dlopen() sets errno to 0 when it is successful, which
2146 // clobbers the value of errno from the user code. This is an AIX
2147 // bug because according to POSIX it should not set errno to 0. To
2148 // workaround before AIX fixes the bug, errno is saved and restored.
2149 int saveErrno = errno;
2150 libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
2151 if (libHandle == NULL) {
2152 _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n",
2153 errno);
2154 assert(0 && "dlopen() failed");
2155 }
2156 xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
2157 dlsym(libHandle, "__xlcxx_personality_v0"));
2158 if (xlcPersonalityV0 == NULL) {
2159 _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
2160 assert(0 && "dlsym() failed");
2161 }
2162 dlclose(libHandle);
2163 errno = saveErrno;
2164 }
2165 }
2166 xlcPersonalityV0InitLock.unlock();
2167 }
2168 handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
2169 _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
2170 reinterpret_cast<void *>(lsda),
2171 reinterpret_cast<void *>(handler));
2172 } else if (TBTable->tb.longtbtable) {
2173 // This frame has the traceback table extension. Possible cases are
2174 // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
2175 // is not EH aware; or, 3) a frame of other languages. We need to figure out
2176 // if the traceback table extension contains the 'eh_info' structure.
2177 //
2178 // We also need to deal with the complexity arising from some XL compiler
2179 // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
2180 // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
2181 // versa. For frames of code generated by those compilers, the 'longtbtable'
2182 // bit may be set but there isn't really a traceback table extension.
2183 //
2184 // In </usr/include/sys/debug.h>, there is the following definition of
2185 // 'struct tbtable_ext'. It is not really a structure but a dummy to
2186 // collect the description of optional parts of the traceback table.
2187 //
2188 // struct tbtable_ext {
2189 // ...
2190 // char alloca_reg; /* Register for alloca automatic storage */
2191 // struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
2192 // unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
2193 // };
2194 //
2195 // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
2196 // following 'alloca_reg' can be treated either as 'struct vec_ext' or
2197 // 'unsigned char xtbtable'. 'xtbtable' bits are defined in
2198 // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
2199 // unused and should not be set. 'struct vec_ext' is defined in
2200 // </usr/include/sys/debug.h> as follows:
2201 //
2202 // struct vec_ext {
2203 // unsigned vr_saved:6; /* Number of non-volatile vector regs saved
2204 // */
2205 // /* first register saved is assumed to be */
2206 // /* 32 - vr_saved */
2207 // unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */
2208 // unsigned has_varargs:1;
2209 // ...
2210 // };
2211 //
2212 // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
2213 // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
2214 // we checks if the 7th bit is set or not because 'xtbtable' should
2215 // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
2216 // in the future to make sure the mitigation works. This mitigation
2217 // is not 100% bullet proof because 'struct vec_ext' may not always have
2218 // 'saves_vrsave' bit set.
2219 //
2220 // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
2221 // checking the 7th bit.
2222
2223 // p points to field name len.
2224 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2225
2226 // Skip fields name_len and name if they exist.
2227 if (TBTable->tb.name_present) {
2228 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2229 charPtr = charPtr + name_len + sizeof(uint16_t);
2230 }
2231
2232 // Skip field alloc_reg if it exists.
2233 if (TBTable->tb.uses_alloca)
2234 ++charPtr;
2235
2236 // Check traceback table bit has_vec. Skip struct vec_ext if it exists.
2237 if (TBTable->tb.has_vec)
2238 // Note struct vec_ext does exist at this point because whether the
2239 // ordering of longtbtable and has_vec bits is correct or not, both
2240 // are set.
2241 charPtr += sizeof(struct vec_ext);
2242
2243 // charPtr points to field 'xtbtable'. Check if the EH info is available.
2244 // Also check if the reserved bit of the extended traceback table field
2245 // 'xtbtable' is set. If it is, the traceback table was incorrectly
2246 // generated by an XL compiler that uses the wrong ordering of 'longtbtable'
2247 // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
2248 // frame.
2249 if ((*charPtr & xTBTableMask::ehInfoBit) &&
2250 !(*charPtr & xTBTableMask::reservedBit)) {
2251 // Mark this frame has the new EH info.
2252 flags = frameType::frameWithEHInfo;
2253
2254 // eh_info is available.
2255 charPtr++;
2256 // The pointer is 4-byte aligned.
2257 if (reinterpret_cast<uintptr_t>(charPtr) % 4)
2258 charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
2259 uintptr_t *ehInfo =
2260 reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
2261 registers.getRegister(2) +
2262 *(reinterpret_cast<uintptr_t *>(charPtr)))));
2263
2264 // ehInfo points to structure en_info. The first member is version.
2265 // Only version 0 is currently supported.
2266 assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
2267 "libunwind: ehInfo version other than 0 is not supported");
2268
2269 // Increment ehInfo to point to member lsda.
2270 ++ehInfo;
2271 lsda = *ehInfo++;
2272
2273 // enInfo now points to member personality.
2274 handler = *ehInfo;
2275
2276 _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
2277 lsda, handler);
2278 }
2279 }
2280
2281 _info.start_ip = start_ip;
2282 _info.end_ip = end_ip;
2283 _info.lsda = lsda;
2284 _info.handler = handler;
2285 _info.gp = 0;
2286 _info.flags = flags;
2287 _info.format = 0;
2288 _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
2289 _info.unwind_info_size = 0;
2290 _info.extra = registers.getRegister(2);
2291
2292 return true;
2293 }
2294
2295 // Step back up the stack following the frame back link.
2296 template <typename A, typename R>
stepWithTBTable(pint_t pc,tbtable * TBTable,R & registers,bool & isSignalFrame)2297 int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
2298 R ®isters, bool &isSignalFrame) {
2299 if (_LIBUNWIND_TRACING_UNWINDING) {
2300 char functionBuf[512];
2301 const char *functionName = functionBuf;
2302 unw_word_t offset;
2303 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2304 functionName = ".anonymous.";
2305 }
2306 _LIBUNWIND_TRACE_UNWINDING(
2307 "%s: Look up traceback table of func=%s at %p, pc=%p, "
2308 "SP=%p, saves_lr=%d, stores_bc=%d",
2309 __func__, functionName, reinterpret_cast<void *>(TBTable),
2310 reinterpret_cast<void *>(pc),
2311 reinterpret_cast<void *>(registers.getSP()), TBTable->tb.saves_lr,
2312 TBTable->tb.stores_bc);
2313 }
2314
2315 #if defined(__powerpc64__)
2316 // Instruction to reload TOC register "ld r2,40(r1)"
2317 const uint32_t loadTOCRegInst = 0xe8410028;
2318 const int32_t unwPPCF0Index = UNW_PPC64_F0;
2319 const int32_t unwPPCV0Index = UNW_PPC64_V0;
2320 #else
2321 // Instruction to reload TOC register "lwz r2,20(r1)"
2322 const uint32_t loadTOCRegInst = 0x80410014;
2323 const int32_t unwPPCF0Index = UNW_PPC_F0;
2324 const int32_t unwPPCV0Index = UNW_PPC_V0;
2325 #endif
2326
2327 // lastStack points to the stack frame of the next routine up.
2328 pint_t curStack = static_cast<pint_t>(registers.getSP());
2329 pint_t lastStack = *reinterpret_cast<pint_t *>(curStack);
2330
2331 if (lastStack == 0)
2332 return UNW_STEP_END;
2333
2334 R newRegisters = registers;
2335
2336 // If backchain is not stored, use the current stack frame.
2337 if (!TBTable->tb.stores_bc)
2338 lastStack = curStack;
2339
2340 // Return address is the address after call site instruction.
2341 pint_t returnAddress;
2342
2343 if (isSignalFrame) {
2344 _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
2345 reinterpret_cast<void *>(lastStack));
2346
2347 sigcontext *sigContext = reinterpret_cast<sigcontext *>(
2348 reinterpret_cast<char *>(lastStack) + STKMINALIGN);
2349 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2350
2351 bool useSTKMIN = false;
2352 if (returnAddress < 0x10000000) {
2353 // Try again using STKMIN.
2354 sigContext = reinterpret_cast<sigcontext *>(
2355 reinterpret_cast<char *>(lastStack) + STKMIN);
2356 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2357 if (returnAddress < 0x10000000) {
2358 _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p from sigcontext=%p",
2359 reinterpret_cast<void *>(returnAddress),
2360 reinterpret_cast<void *>(sigContext));
2361 return UNW_EBADFRAME;
2362 }
2363 useSTKMIN = true;
2364 }
2365 _LIBUNWIND_TRACE_UNWINDING("Returning from a signal handler %s: "
2366 "sigContext=%p, returnAddress=%p. "
2367 "Seems to be a valid address",
2368 useSTKMIN ? "STKMIN" : "STKMINALIGN",
2369 reinterpret_cast<void *>(sigContext),
2370 reinterpret_cast<void *>(returnAddress));
2371
2372 // Restore the condition register from sigcontext.
2373 newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
2374
2375 // Save the LR in sigcontext for stepping up when the function that
2376 // raised the signal is a leaf function. This LR has the return address
2377 // to the caller of the leaf function.
2378 newRegisters.setLR(sigContext->sc_jmpbuf.jmp_context.lr);
2379 _LIBUNWIND_TRACE_UNWINDING(
2380 "Save LR=%p from sigcontext",
2381 reinterpret_cast<void *>(sigContext->sc_jmpbuf.jmp_context.lr));
2382
2383 // Restore GPRs from sigcontext.
2384 for (int i = 0; i < 32; ++i)
2385 newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
2386
2387 // Restore FPRs from sigcontext.
2388 for (int i = 0; i < 32; ++i)
2389 newRegisters.setFloatRegister(i + unwPPCF0Index,
2390 sigContext->sc_jmpbuf.jmp_context.fpr[i]);
2391
2392 // Restore vector registers if there is an associated extended context
2393 // structure.
2394 if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
2395 ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
2396 if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
2397 for (int i = 0; i < 32; ++i)
2398 newRegisters.setVectorRegister(
2399 i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
2400 &(uContext->__extctx->__vmx.__vr[i]))));
2401 }
2402 }
2403 } else {
2404 // Step up a normal frame.
2405
2406 if (!TBTable->tb.saves_lr && registers.getLR()) {
2407 // This case should only occur if we were called from a signal handler
2408 // and the signal occurred in a function that doesn't save the LR.
2409 returnAddress = static_cast<pint_t>(registers.getLR());
2410 _LIBUNWIND_TRACE_UNWINDING("Use saved LR=%p",
2411 reinterpret_cast<void *>(returnAddress));
2412 } else {
2413 // Otherwise, use the LR value in the stack link area.
2414 returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
2415 }
2416
2417 // Reset LR in the current context.
2418 newRegisters.setLR(static_cast<uintptr_t>(NULL));
2419
2420 _LIBUNWIND_TRACE_UNWINDING(
2421 "Extract info from lastStack=%p, returnAddress=%p",
2422 reinterpret_cast<void *>(lastStack),
2423 reinterpret_cast<void *>(returnAddress));
2424 _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d",
2425 TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
2426 TBTable->tb.saves_cr);
2427
2428 // Restore FP registers.
2429 char *ptrToRegs = reinterpret_cast<char *>(lastStack);
2430 double *FPRegs = reinterpret_cast<double *>(
2431 ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
2432 for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
2433 newRegisters.setFloatRegister(
2434 32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
2435
2436 // Restore GP registers.
2437 ptrToRegs = reinterpret_cast<char *>(FPRegs);
2438 uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
2439 ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
2440 for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
2441 newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
2442
2443 // Restore Vector registers.
2444 ptrToRegs = reinterpret_cast<char *>(GPRegs);
2445
2446 // Restore vector registers only if this is a Clang frame. Also
2447 // check if traceback table bit has_vec is set. If it is, structure
2448 // vec_ext is available.
2449 if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
2450
2451 // Get to the vec_ext structure to check if vector registers are saved.
2452 uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2453
2454 // Skip field parminfo if exists.
2455 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2456 ++p;
2457
2458 // Skip field tb_offset if exists.
2459 if (TBTable->tb.has_tboff)
2460 ++p;
2461
2462 // Skip field hand_mask if exists.
2463 if (TBTable->tb.int_hndl)
2464 ++p;
2465
2466 // Skip fields ctl_info and ctl_info_disp if exist.
2467 if (TBTable->tb.has_ctl) {
2468 // Skip field ctl_info.
2469 ++p;
2470 // Skip field ctl_info_disp.
2471 ++p;
2472 }
2473
2474 // Skip fields name_len and name if exist.
2475 // p is supposed to point to field name_len now.
2476 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2477 if (TBTable->tb.name_present) {
2478 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2479 charPtr = charPtr + name_len + sizeof(uint16_t);
2480 }
2481
2482 // Skip field alloc_reg if it exists.
2483 if (TBTable->tb.uses_alloca)
2484 ++charPtr;
2485
2486 struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
2487
2488 _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d", vec_ext->vr_saved);
2489
2490 // Restore vector register(s) if saved on the stack.
2491 if (vec_ext->vr_saved) {
2492 // Saved vector registers are 16-byte aligned.
2493 if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
2494 ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
2495 v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
2496 sizeof(v128));
2497 for (int i = 0; i < vec_ext->vr_saved; ++i) {
2498 newRegisters.setVectorRegister(
2499 32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
2500 }
2501 }
2502 }
2503 if (TBTable->tb.saves_cr) {
2504 // Get the saved condition register. The condition register is only
2505 // a single word.
2506 newRegisters.setCR(
2507 *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
2508 }
2509
2510 // Restore the SP.
2511 newRegisters.setSP(lastStack);
2512
2513 // The first instruction after return.
2514 uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
2515
2516 // Do we need to set the TOC register?
2517 _LIBUNWIND_TRACE_UNWINDING(
2518 "Current gpr2=%p",
2519 reinterpret_cast<void *>(newRegisters.getRegister(2)));
2520 if (firstInstruction == loadTOCRegInst) {
2521 _LIBUNWIND_TRACE_UNWINDING(
2522 "Set gpr2=%p from frame",
2523 reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
2524 newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
2525 }
2526 }
2527 _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
2528 reinterpret_cast<void *>(lastStack),
2529 reinterpret_cast<void *>(returnAddress),
2530 reinterpret_cast<void *>(pc));
2531
2532 // The return address is the address after call site instruction, so
2533 // setting IP to that simulates a return.
2534 newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
2535
2536 // Simulate the step by replacing the register set with the new ones.
2537 registers = newRegisters;
2538
2539 // Check if the next frame is a signal frame.
2540 pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2541
2542 // Return address is the address after call site instruction.
2543 pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
2544
2545 if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
2546 _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
2547 "nextStack=%p, next return address=%p\n",
2548 reinterpret_cast<void *>(nextStack),
2549 reinterpret_cast<void *>(nextReturnAddress));
2550 isSignalFrame = true;
2551 } else {
2552 isSignalFrame = false;
2553 }
2554 return UNW_STEP_SUCCESS;
2555 }
2556 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2557
2558 template <typename A, typename R>
setInfoBasedOnIPRegister(bool isReturnAddress)2559 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
2560 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2561 _isSigReturn = false;
2562 #endif
2563
2564 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2565 #if defined(_LIBUNWIND_ARM_EHABI)
2566 // Remove the thumb bit so the IP represents the actual instruction address.
2567 // This matches the behaviour of _Unwind_GetIP on arm.
2568 pc &= (pint_t)~0x1;
2569 #endif
2570
2571 // Exit early if at the top of the stack.
2572 if (pc == 0) {
2573 _unwindInfoMissing = true;
2574 return;
2575 }
2576
2577 // If the last line of a function is a "throw" the compiler sometimes
2578 // emits no instructions after the call to __cxa_throw. This means
2579 // the return address is actually the start of the next function.
2580 // To disambiguate this, back up the pc when we know it is a return
2581 // address.
2582 if (isReturnAddress)
2583 #if defined(_AIX)
2584 // PC needs to be a 4-byte aligned address to be able to look for a
2585 // word of 0 that indicates the start of the traceback table at the end
2586 // of a function on AIX.
2587 pc -= 4;
2588 #else
2589 --pc;
2590 #endif
2591
2592 #if !(defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)) && \
2593 !defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2594 // In case of this is frame of signal handler, the IP saved in the signal
2595 // handler points to first non-executed instruction, while FDE/CIE expects IP
2596 // to be after the first non-executed instruction.
2597 if (_isSignalFrame)
2598 ++pc;
2599 #endif
2600
2601 // Ask address space object to find unwind sections for this pc.
2602 UnwindInfoSections sects;
2603 if (_addressSpace.findUnwindSections(pc, sects)) {
2604 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2605 // If there is a compact unwind encoding table, look there first.
2606 if (sects.compact_unwind_section != 0) {
2607 if (this->getInfoFromCompactEncodingSection(pc, sects)) {
2608 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2609 // Found info in table, done unless encoding says to use dwarf.
2610 uint32_t dwarfOffset;
2611 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
2612 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
2613 // found info in dwarf, done
2614 return;
2615 }
2616 }
2617 #endif
2618 // If unwind table has entry, but entry says there is no unwind info,
2619 // record that we have no unwind info.
2620 if (_info.format == 0)
2621 _unwindInfoMissing = true;
2622 return;
2623 }
2624 }
2625 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2626
2627 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2628 // If there is SEH unwind info, look there next.
2629 if (this->getInfoFromSEH(pc))
2630 return;
2631 #endif
2632
2633 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2634 // If there is unwind info in the traceback table, look there next.
2635 if (this->getInfoFromTBTable(pc, _registers))
2636 return;
2637 #endif
2638
2639 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2640 // If there is dwarf unwind info, look there next.
2641 if (sects.dwarf_section != 0) {
2642 if (this->getInfoFromDwarfSection(pc, sects)) {
2643 // found info in dwarf, done
2644 return;
2645 }
2646 }
2647 #endif
2648
2649 #if defined(_LIBUNWIND_ARM_EHABI)
2650 // If there is ARM EHABI unwind info, look there next.
2651 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
2652 return;
2653 #endif
2654 }
2655
2656 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2657 // There is no static unwind info for this pc. Look to see if an FDE was
2658 // dynamically registered for it.
2659 pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
2660 pc);
2661 if (cachedFDE != 0) {
2662 typename CFI_Parser<A>::FDE_Info fdeInfo;
2663 typename CFI_Parser<A>::CIE_Info cieInfo;
2664 if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
2665 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2666 return;
2667 }
2668
2669 // Lastly, ask AddressSpace object about platform specific ways to locate
2670 // other FDEs.
2671 pint_t fde;
2672 if (_addressSpace.findOtherFDE(pc, fde)) {
2673 typename CFI_Parser<A>::FDE_Info fdeInfo;
2674 typename CFI_Parser<A>::CIE_Info cieInfo;
2675 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
2676 // Double check this FDE is for a function that includes the pc.
2677 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
2678 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2679 return;
2680 }
2681 }
2682 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2683
2684 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2685 if (setInfoForSigReturn())
2686 return;
2687 #endif
2688
2689 // no unwind info, flag that we can't reliably unwind
2690 _unwindInfoMissing = true;
2691 }
2692
2693 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2694 defined(_LIBUNWIND_TARGET_AARCH64)
2695 template <typename A, typename R>
setInfoForSigReturn(Registers_arm64 &)2696 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
2697 // Look for the sigreturn trampoline. The trampoline's body is two
2698 // specific instructions (see below). Typically the trampoline comes from the
2699 // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
2700 // own restorer function, though, or user-mode QEMU might write a trampoline
2701 // onto the stack.
2702 //
2703 // This special code path is a fallback that is only used if the trampoline
2704 // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
2705 // constant for the PC needs to be defined before DWARF can handle a signal
2706 // trampoline. This code may segfault if the target PC is unreadable, e.g.:
2707 // - The PC points at a function compiled without unwind info, and which is
2708 // part of an execute-only mapping (e.g. using -Wl,--execute-only).
2709 // - The PC is invalid and happens to point to unreadable or unmapped memory.
2710 //
2711 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
2712 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2713 // The PC might contain an invalid address if the unwind info is bad, so
2714 // directly accessing it could cause a SIGSEGV.
2715 if (!isReadableAddr(pc))
2716 return false;
2717 auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2718 // Look for instructions: mov x8, #0x8b; svc #0x0
2719 if (instructions[0] != 0xd2801168 || instructions[1] != 0xd4000001)
2720 return false;
2721
2722 _info = {};
2723 _info.start_ip = pc;
2724 _info.end_ip = pc + 4;
2725 _isSigReturn = true;
2726 return true;
2727 }
2728
2729 template <typename A, typename R>
stepThroughSigReturn(Registers_arm64 &)2730 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
2731 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2732 // - 128-byte siginfo struct
2733 // - ucontext struct:
2734 // - 8-byte long (uc_flags)
2735 // - 8-byte pointer (uc_link)
2736 // - 24-byte stack_t
2737 // - 128-byte signal set
2738 // - 8 bytes of padding because sigcontext has 16-byte alignment
2739 // - sigcontext/mcontext_t
2740 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
2741 const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
2742
2743 // Offsets from sigcontext to each register.
2744 const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
2745 const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
2746 const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
2747
2748 pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2749
2750 for (int i = 0; i <= 30; ++i) {
2751 uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
2752 static_cast<pint_t>(i * 8));
2753 _registers.setRegister(UNW_AARCH64_X0 + i, value);
2754 }
2755 _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
2756 _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
2757 _isSignalFrame = true;
2758 return UNW_STEP_SUCCESS;
2759 }
2760 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2761 // defined(_LIBUNWIND_TARGET_AARCH64)
2762
2763 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2764 defined(_LIBUNWIND_TARGET_RISCV)
2765 template <typename A, typename R>
setInfoForSigReturn(Registers_riscv &)2766 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_riscv &) {
2767 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2768 // The PC might contain an invalid address if the unwind info is bad, so
2769 // directly accessing it could cause a SIGSEGV.
2770 if (!isReadableAddr(pc))
2771 return false;
2772 const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2773 // Look for the two instructions used in the sigreturn trampoline
2774 // __vdso_rt_sigreturn:
2775 //
2776 // 0x08b00893 li a7,0x8b
2777 // 0x00000073 ecall
2778 if (instructions[0] != 0x08b00893 || instructions[1] != 0x00000073)
2779 return false;
2780
2781 _info = {};
2782 _info.start_ip = pc;
2783 _info.end_ip = pc + 4;
2784 _isSigReturn = true;
2785 return true;
2786 }
2787
2788 template <typename A, typename R>
stepThroughSigReturn(Registers_riscv &)2789 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_riscv &) {
2790 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2791 // - 128-byte siginfo struct
2792 // - ucontext_t struct:
2793 // - 8-byte long (__uc_flags)
2794 // - 8-byte pointer (*uc_link)
2795 // - 24-byte uc_stack
2796 // - 8-byte uc_sigmask
2797 // - 120-byte of padding to allow sigset_t to be expanded in the future
2798 // - 8 bytes of padding because sigcontext has 16-byte alignment
2799 // - struct sigcontext uc_mcontext
2800 // [1]
2801 // https://github.com/torvalds/linux/blob/master/arch/riscv/kernel/signal.c
2802 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2803
2804 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2805 _registers.setIP(_addressSpace.get64(sigctx));
2806 for (int i = UNW_RISCV_X1; i <= UNW_RISCV_X31; ++i) {
2807 uint64_t value = _addressSpace.get64(sigctx + static_cast<pint_t>(i * 8));
2808 _registers.setRegister(i, value);
2809 }
2810 _isSignalFrame = true;
2811 return UNW_STEP_SUCCESS;
2812 }
2813 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2814 // defined(_LIBUNWIND_TARGET_RISCV)
2815
2816 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2817 defined(_LIBUNWIND_TARGET_S390X)
2818 template <typename A, typename R>
setInfoForSigReturn(Registers_s390x &)2819 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
2820 // Look for the sigreturn trampoline. The trampoline's body is a
2821 // specific instruction (see below). Typically the trampoline comes from the
2822 // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its
2823 // own restorer function, though, or user-mode QEMU might write a trampoline
2824 // onto the stack.
2825 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2826 // The PC might contain an invalid address if the unwind info is bad, so
2827 // directly accessing it could cause a SIGSEGV.
2828 if (!isReadableAddr(pc))
2829 return false;
2830 const auto inst = *reinterpret_cast<const uint16_t *>(pc);
2831 if (inst == 0x0a77 || inst == 0x0aad) {
2832 _info = {};
2833 _info.start_ip = pc;
2834 _info.end_ip = pc + 2;
2835 _isSigReturn = true;
2836 return true;
2837 }
2838 return false;
2839 }
2840
2841 template <typename A, typename R>
stepThroughSigReturn(Registers_s390x &)2842 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
2843 // Determine current SP.
2844 const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP));
2845 // According to the s390x ABI, the CFA is at (incoming) SP + 160.
2846 const pint_t cfa = sp + 160;
2847
2848 // Determine current PC and instruction there (this must be either
2849 // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn").
2850 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2851 const uint16_t inst = _addressSpace.get16(pc);
2852
2853 // Find the addresses of the signo and sigcontext in the frame.
2854 pint_t pSigctx = 0;
2855 pint_t pSigno = 0;
2856
2857 // "svc __NR_sigreturn" uses a non-RT signal trampoline frame.
2858 if (inst == 0x0a77) {
2859 // Layout of a non-RT signal trampoline frame, starting at the CFA:
2860 // - 8-byte signal mask
2861 // - 8-byte pointer to sigcontext, followed by signo
2862 // - 4-byte signo
2863 pSigctx = _addressSpace.get64(cfa + 8);
2864 pSigno = pSigctx + 344;
2865 }
2866
2867 // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame.
2868 if (inst == 0x0aad) {
2869 // Layout of a RT signal trampoline frame, starting at the CFA:
2870 // - 8-byte retcode (+ alignment)
2871 // - 128-byte siginfo struct (starts with signo)
2872 // - ucontext struct:
2873 // - 8-byte long (uc_flags)
2874 // - 8-byte pointer (uc_link)
2875 // - 24-byte stack_t
2876 // - 8 bytes of padding because sigcontext has 16-byte alignment
2877 // - sigcontext/mcontext_t
2878 pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8;
2879 pSigno = cfa + 8;
2880 }
2881
2882 assert(pSigctx != 0);
2883 assert(pSigno != 0);
2884
2885 // Offsets from sigcontext to each register.
2886 const pint_t kOffsetPc = 8;
2887 const pint_t kOffsetGprs = 16;
2888 const pint_t kOffsetFprs = 216;
2889
2890 // Restore all registers.
2891 for (int i = 0; i < 16; ++i) {
2892 uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs +
2893 static_cast<pint_t>(i * 8));
2894 _registers.setRegister(UNW_S390X_R0 + i, value);
2895 }
2896 for (int i = 0; i < 16; ++i) {
2897 static const int fpr[16] = {
2898 UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3,
2899 UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7,
2900 UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11,
2901 UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15
2902 };
2903 double value = _addressSpace.getDouble(pSigctx + kOffsetFprs +
2904 static_cast<pint_t>(i * 8));
2905 _registers.setFloatRegister(fpr[i], value);
2906 }
2907 _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc));
2908
2909 // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
2910 // after the faulting instruction rather than before it.
2911 // Do not set _isSignalFrame in that case.
2912 uint32_t signo = _addressSpace.get32(pSigno);
2913 _isSignalFrame = (signo != 4 && signo != 5 && signo != 8);
2914
2915 return UNW_STEP_SUCCESS;
2916 }
2917 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2918 // defined(_LIBUNWIND_TARGET_S390X)
2919
step(bool stage2)2920 template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
2921 (void)stage2;
2922 // Bottom of stack is defined is when unwind info cannot be found.
2923 if (_unwindInfoMissing)
2924 return UNW_STEP_END;
2925
2926 // Use unwinding info to modify register set as if function returned.
2927 int result;
2928 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2929 if (_isSigReturn) {
2930 result = this->stepThroughSigReturn();
2931 } else
2932 #endif
2933 {
2934 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2935 result = this->stepWithCompactEncoding(stage2);
2936 #elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2937 result = this->stepWithSEHData();
2938 #elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2939 result = this->stepWithTBTableData();
2940 #elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2941 result = this->stepWithDwarfFDE(stage2);
2942 #elif defined(_LIBUNWIND_ARM_EHABI)
2943 result = this->stepWithEHABI();
2944 #else
2945 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
2946 _LIBUNWIND_SUPPORT_SEH_UNWIND or \
2947 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
2948 _LIBUNWIND_ARM_EHABI
2949 #endif
2950 }
2951
2952 // update info based on new PC
2953 if (result == UNW_STEP_SUCCESS) {
2954 this->setInfoBasedOnIPRegister(true);
2955 if (_unwindInfoMissing)
2956 return UNW_STEP_END;
2957 }
2958
2959 return result;
2960 }
2961
2962 template <typename A, typename R>
getInfo(unw_proc_info_t * info)2963 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
2964 if (_unwindInfoMissing)
2965 memset(info, 0, sizeof(*info));
2966 else
2967 *info = _info;
2968 }
2969
2970 template <typename A, typename R>
getFunctionName(char * buf,size_t bufLen,unw_word_t * offset)2971 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
2972 unw_word_t *offset) {
2973 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
2974 buf, bufLen, offset);
2975 }
2976
2977 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2978 template <typename A, typename R>
isReadableAddr(const pint_t addr) const2979 bool UnwindCursor<A, R>::isReadableAddr(const pint_t addr) const {
2980 // We use SYS_rt_sigprocmask, inspired by Abseil's AddressIsReadable.
2981
2982 const auto sigsetAddr = reinterpret_cast<sigset_t *>(addr);
2983 // We have to check that addr is nullptr because sigprocmask allows that
2984 // as an argument without failure.
2985 if (!sigsetAddr)
2986 return false;
2987 const auto saveErrno = errno;
2988 // We MUST use a raw syscall here, as wrappers may try to access
2989 // sigsetAddr which may cause a SIGSEGV. A raw syscall however is
2990 // safe. Additionally, we need to pass the kernel_sigset_size, which is
2991 // different from libc sizeof(sigset_t). For the majority of architectures,
2992 // it's 64 bits (_NSIG), and libc NSIG is _NSIG + 1.
2993 const auto kernelSigsetSize = NSIG / 8;
2994 [[maybe_unused]] const int Result = syscall(
2995 SYS_rt_sigprocmask, /*how=*/~0, sigsetAddr, nullptr, kernelSigsetSize);
2996 // Because our "how" is invalid, this syscall should always fail, and our
2997 // errno should always be EINVAL or an EFAULT. This relies on the Linux
2998 // kernel to check copy_from_user before checking if the "how" argument is
2999 // invalid.
3000 assert(Result == -1);
3001 assert(errno == EFAULT || errno == EINVAL);
3002 const auto readable = errno != EFAULT;
3003 errno = saveErrno;
3004 return readable;
3005 }
3006 #endif
3007
3008 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
__libunwind_cet_get_registers(unw_cursor_t * cursor)3009 extern "C" void *__libunwind_cet_get_registers(unw_cursor_t *cursor) {
3010 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
3011 return co->get_registers();
3012 }
3013 #endif
3014 } // namespace libunwind
3015
3016 #endif // __UNWINDCURSOR_HPP__
3017