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 "shadow_stack_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) || \
35 defined(_LIBUNWIND_TARGET_LOONGARCH) || \
36 defined(_LIBUNWIND_TARGET_RISCV) || defined(_LIBUNWIND_TARGET_S390X))
37 #include <errno.h>
38 #include <signal.h>
39 #include <sys/syscall.h>
40 #include <unistd.h>
41 #define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
42 #endif
43
44 #if defined(_LIBUNWIND_TARGET_HAIKU) && defined(_LIBUNWIND_TARGET_X86_64)
45 #include <OS.h>
46 #include <signal.h>
47 #define _LIBUNWIND_CHECK_HAIKU_SIGRETURN 1
48 #endif
49
50 #include "AddressSpace.hpp"
51 #include "CompactUnwinder.hpp"
52 #include "config.h"
53 #include "DwarfInstructions.hpp"
54 #include "EHHeaderParser.hpp"
55 #include "libunwind.h"
56 #include "libunwind_ext.h"
57 #include "Registers.hpp"
58 #include "RWMutex.hpp"
59 #include "Unwind-EHABI.h"
60
61 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
62 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
63 // earlier) SDKs.
64 // MinGW-w64 has always provided this struct.
65 #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
66 !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
67 struct _DISPATCHER_CONTEXT {
68 ULONG64 ControlPc;
69 ULONG64 ImageBase;
70 PRUNTIME_FUNCTION FunctionEntry;
71 ULONG64 EstablisherFrame;
72 ULONG64 TargetIp;
73 PCONTEXT ContextRecord;
74 PEXCEPTION_ROUTINE LanguageHandler;
75 PVOID HandlerData;
76 PUNWIND_HISTORY_TABLE HistoryTable;
77 ULONG ScopeIndex;
78 ULONG Fill0;
79 };
80 #endif
81
82 struct UNWIND_INFO {
83 uint8_t Version : 3;
84 uint8_t Flags : 5;
85 uint8_t SizeOfProlog;
86 uint8_t CountOfCodes;
87 uint8_t FrameRegister : 4;
88 uint8_t FrameOffset : 4;
89 uint16_t UnwindCodes[2];
90 };
91
92 #pragma clang diagnostic push
93 #pragma clang diagnostic ignored "-Wgnu-anonymous-struct"
94 union UNWIND_INFO_ARM {
95 DWORD HeaderData;
96 struct {
97 DWORD FunctionLength : 18;
98 DWORD Version : 2;
99 DWORD ExceptionDataPresent : 1;
100 DWORD EpilogInHeader : 1;
101 DWORD FunctionFragment : 1;
102 DWORD EpilogCount : 5;
103 DWORD CodeWords : 4;
104 };
105 };
106 #pragma clang diagnostic pop
107
108 extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
109 int, _Unwind_Action, uint64_t, _Unwind_Exception *,
110 struct _Unwind_Context *);
111
112 #endif
113
114 namespace libunwind {
115
116 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
117 /// Cache of recently found FDEs.
118 template <typename A>
119 class _LIBUNWIND_HIDDEN DwarfFDECache {
120 typedef typename A::pint_t pint_t;
121 public:
122 static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
123 static pint_t findFDE(pint_t mh, pint_t pc);
124 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
125 static void removeAllIn(pint_t mh);
126 static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
127 unw_word_t ip_end,
128 unw_word_t fde, unw_word_t mh));
129
130 private:
131
132 struct entry {
133 pint_t mh;
134 pint_t ip_start;
135 pint_t ip_end;
136 pint_t fde;
137 };
138
139 // These fields are all static to avoid needing an initializer.
140 // There is only one instance of this class per process.
141 static RWMutex _lock;
142 #ifdef __APPLE__
143 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
144 static bool _registeredForDyldUnloads;
145 #endif
146 static entry *_buffer;
147 static entry *_bufferUsed;
148 static entry *_bufferEnd;
149 static entry _initialBuffer[64];
150 };
151
152 template <typename A>
153 typename DwarfFDECache<A>::entry *
154 DwarfFDECache<A>::_buffer = _initialBuffer;
155
156 template <typename A>
157 typename DwarfFDECache<A>::entry *
158 DwarfFDECache<A>::_bufferUsed = _initialBuffer;
159
160 template <typename A>
161 typename DwarfFDECache<A>::entry *
162 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
163
164 template <typename A>
165 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
166
167 template <typename A>
168 RWMutex DwarfFDECache<A>::_lock;
169
170 #ifdef __APPLE__
171 template <typename A>
172 bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
173 #endif
174
175 template <typename A>
findFDE(pint_t mh,pint_t pc)176 typename DwarfFDECache<A>::pint_t DwarfFDECache<A>::findFDE(pint_t mh,
177 pint_t pc) {
178 pint_t result = 0;
179 _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
180 for (entry *p = _buffer; p < _bufferUsed; ++p) {
181 if ((mh == p->mh) || (mh == kSearchAll)) {
182 if ((p->ip_start <= pc) && (pc < p->ip_end)) {
183 result = p->fde;
184 break;
185 }
186 }
187 }
188 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
189 return result;
190 }
191
192 template <typename A>
add(pint_t mh,pint_t ip_start,pint_t ip_end,pint_t fde)193 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
194 pint_t fde) {
195 #if !defined(_LIBUNWIND_NO_HEAP)
196 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
197 if (_bufferUsed >= _bufferEnd) {
198 size_t oldSize = (size_t)(_bufferEnd - _buffer);
199 size_t newSize = oldSize * 4;
200 // Can't use operator new (we are below it).
201 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
202 memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
203 if (_buffer != _initialBuffer)
204 free(_buffer);
205 _buffer = newBuffer;
206 _bufferUsed = &newBuffer[oldSize];
207 _bufferEnd = &newBuffer[newSize];
208 }
209 _bufferUsed->mh = mh;
210 _bufferUsed->ip_start = ip_start;
211 _bufferUsed->ip_end = ip_end;
212 _bufferUsed->fde = fde;
213 ++_bufferUsed;
214 #ifdef __APPLE__
215 if (!_registeredForDyldUnloads) {
216 _dyld_register_func_for_remove_image(&dyldUnloadHook);
217 _registeredForDyldUnloads = true;
218 }
219 #endif
220 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
221 #endif
222 }
223
224 template <typename A>
removeAllIn(pint_t mh)225 void DwarfFDECache<A>::removeAllIn(pint_t mh) {
226 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
227 entry *d = _buffer;
228 for (const entry *s = _buffer; s < _bufferUsed; ++s) {
229 if (s->mh != mh) {
230 if (d != s)
231 *d = *s;
232 ++d;
233 }
234 }
235 _bufferUsed = d;
236 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
237 }
238
239 #ifdef __APPLE__
240 template <typename A>
dyldUnloadHook(const struct mach_header * mh,intptr_t)241 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
242 removeAllIn((pint_t) mh);
243 }
244 #endif
245
246 template <typename A>
iterateCacheEntries(void (* func)(unw_word_t ip_start,unw_word_t ip_end,unw_word_t fde,unw_word_t mh))247 void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
248 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
249 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
250 for (entry *p = _buffer; p < _bufferUsed; ++p) {
251 (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
252 }
253 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
254 }
255 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
256
257 #define arrayoffsetof(type, index, field) \
258 (sizeof(type) * (index) + offsetof(type, field))
259
260 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
261 template <typename A> class UnwindSectionHeader {
262 public:
UnwindSectionHeader(A & addressSpace,typename A::pint_t addr)263 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
264 : _addressSpace(addressSpace), _addr(addr) {}
265
version() const266 uint32_t version() const {
267 return _addressSpace.get32(_addr +
268 offsetof(unwind_info_section_header, version));
269 }
commonEncodingsArraySectionOffset() const270 uint32_t commonEncodingsArraySectionOffset() const {
271 return _addressSpace.get32(_addr +
272 offsetof(unwind_info_section_header,
273 commonEncodingsArraySectionOffset));
274 }
commonEncodingsArrayCount() const275 uint32_t commonEncodingsArrayCount() const {
276 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
277 commonEncodingsArrayCount));
278 }
personalityArraySectionOffset() const279 uint32_t personalityArraySectionOffset() const {
280 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
281 personalityArraySectionOffset));
282 }
personalityArrayCount() const283 uint32_t personalityArrayCount() const {
284 return _addressSpace.get32(
285 _addr + offsetof(unwind_info_section_header, personalityArrayCount));
286 }
indexSectionOffset() const287 uint32_t indexSectionOffset() const {
288 return _addressSpace.get32(
289 _addr + offsetof(unwind_info_section_header, indexSectionOffset));
290 }
indexCount() const291 uint32_t indexCount() const {
292 return _addressSpace.get32(
293 _addr + offsetof(unwind_info_section_header, indexCount));
294 }
295
296 private:
297 A &_addressSpace;
298 typename A::pint_t _addr;
299 };
300
301 template <typename A> class UnwindSectionIndexArray {
302 public:
UnwindSectionIndexArray(A & addressSpace,typename A::pint_t addr)303 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
304 : _addressSpace(addressSpace), _addr(addr) {}
305
functionOffset(uint32_t index) const306 uint32_t functionOffset(uint32_t index) const {
307 return _addressSpace.get32(
308 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
309 functionOffset));
310 }
secondLevelPagesSectionOffset(uint32_t index) const311 uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
312 return _addressSpace.get32(
313 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
314 secondLevelPagesSectionOffset));
315 }
lsdaIndexArraySectionOffset(uint32_t index) const316 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
317 return _addressSpace.get32(
318 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
319 lsdaIndexArraySectionOffset));
320 }
321
322 private:
323 A &_addressSpace;
324 typename A::pint_t _addr;
325 };
326
327 template <typename A> class UnwindSectionRegularPageHeader {
328 public:
UnwindSectionRegularPageHeader(A & addressSpace,typename A::pint_t addr)329 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
330 : _addressSpace(addressSpace), _addr(addr) {}
331
kind() const332 uint32_t kind() const {
333 return _addressSpace.get32(
334 _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
335 }
entryPageOffset() const336 uint16_t entryPageOffset() const {
337 return _addressSpace.get16(
338 _addr + offsetof(unwind_info_regular_second_level_page_header,
339 entryPageOffset));
340 }
entryCount() const341 uint16_t entryCount() const {
342 return _addressSpace.get16(
343 _addr +
344 offsetof(unwind_info_regular_second_level_page_header, entryCount));
345 }
346
347 private:
348 A &_addressSpace;
349 typename A::pint_t _addr;
350 };
351
352 template <typename A> class UnwindSectionRegularArray {
353 public:
UnwindSectionRegularArray(A & addressSpace,typename A::pint_t addr)354 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
355 : _addressSpace(addressSpace), _addr(addr) {}
356
functionOffset(uint32_t index) const357 uint32_t functionOffset(uint32_t index) const {
358 return _addressSpace.get32(
359 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
360 functionOffset));
361 }
encoding(uint32_t index) const362 uint32_t encoding(uint32_t index) const {
363 return _addressSpace.get32(
364 _addr +
365 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
366 }
367
368 private:
369 A &_addressSpace;
370 typename A::pint_t _addr;
371 };
372
373 template <typename A> class UnwindSectionCompressedPageHeader {
374 public:
UnwindSectionCompressedPageHeader(A & addressSpace,typename A::pint_t addr)375 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
376 : _addressSpace(addressSpace), _addr(addr) {}
377
kind() const378 uint32_t kind() const {
379 return _addressSpace.get32(
380 _addr +
381 offsetof(unwind_info_compressed_second_level_page_header, kind));
382 }
entryPageOffset() const383 uint16_t entryPageOffset() const {
384 return _addressSpace.get16(
385 _addr + offsetof(unwind_info_compressed_second_level_page_header,
386 entryPageOffset));
387 }
entryCount() const388 uint16_t entryCount() const {
389 return _addressSpace.get16(
390 _addr +
391 offsetof(unwind_info_compressed_second_level_page_header, entryCount));
392 }
encodingsPageOffset() const393 uint16_t encodingsPageOffset() const {
394 return _addressSpace.get16(
395 _addr + offsetof(unwind_info_compressed_second_level_page_header,
396 encodingsPageOffset));
397 }
encodingsCount() const398 uint16_t encodingsCount() const {
399 return _addressSpace.get16(
400 _addr + offsetof(unwind_info_compressed_second_level_page_header,
401 encodingsCount));
402 }
403
404 private:
405 A &_addressSpace;
406 typename A::pint_t _addr;
407 };
408
409 template <typename A> class UnwindSectionCompressedArray {
410 public:
UnwindSectionCompressedArray(A & addressSpace,typename A::pint_t addr)411 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
412 : _addressSpace(addressSpace), _addr(addr) {}
413
functionOffset(uint32_t index) const414 uint32_t functionOffset(uint32_t index) const {
415 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
416 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
417 }
encodingIndex(uint32_t index) const418 uint16_t encodingIndex(uint32_t index) const {
419 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
420 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
421 }
422
423 private:
424 A &_addressSpace;
425 typename A::pint_t _addr;
426 };
427
428 template <typename A> class UnwindSectionLsdaArray {
429 public:
UnwindSectionLsdaArray(A & addressSpace,typename A::pint_t addr)430 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
431 : _addressSpace(addressSpace), _addr(addr) {}
432
functionOffset(uint32_t index) const433 uint32_t functionOffset(uint32_t index) const {
434 return _addressSpace.get32(
435 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
436 index, functionOffset));
437 }
lsdaOffset(uint32_t index) const438 uint32_t lsdaOffset(uint32_t index) const {
439 return _addressSpace.get32(
440 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
441 index, lsdaOffset));
442 }
443
444 private:
445 A &_addressSpace;
446 typename A::pint_t _addr;
447 };
448 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
449
450 class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
451 public:
452 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
453 // This avoids an unnecessary dependency to libc++abi.
operator delete(void *,size_t)454 void operator delete(void *, size_t) {}
455
~AbstractUnwindCursor()456 virtual ~AbstractUnwindCursor() {}
validReg(int)457 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
getReg(int)458 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
setReg(int,unw_word_t)459 virtual void setReg(int, unw_word_t) {
460 _LIBUNWIND_ABORT("setReg not implemented");
461 }
validFloatReg(int)462 virtual bool validFloatReg(int) {
463 _LIBUNWIND_ABORT("validFloatReg not implemented");
464 }
getFloatReg(int)465 virtual unw_fpreg_t getFloatReg(int) {
466 _LIBUNWIND_ABORT("getFloatReg not implemented");
467 }
setFloatReg(int,unw_fpreg_t)468 virtual void setFloatReg(int, unw_fpreg_t) {
469 _LIBUNWIND_ABORT("setFloatReg not implemented");
470 }
step(bool=false)471 virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); }
getInfo(unw_proc_info_t *)472 virtual void getInfo(unw_proc_info_t *) {
473 _LIBUNWIND_ABORT("getInfo not implemented");
474 }
jumpto()475 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
isSignalFrame()476 virtual bool isSignalFrame() {
477 _LIBUNWIND_ABORT("isSignalFrame not implemented");
478 }
getFunctionName(char *,size_t,unw_word_t *)479 virtual bool getFunctionName(char *, size_t, unw_word_t *) {
480 _LIBUNWIND_ABORT("getFunctionName not implemented");
481 }
setInfoBasedOnIPRegister(bool=false)482 virtual void setInfoBasedOnIPRegister(bool = false) {
483 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
484 }
getRegisterName(int)485 virtual const char *getRegisterName(int) {
486 _LIBUNWIND_ABORT("getRegisterName not implemented");
487 }
488 #ifdef __arm__
saveVFPAsX()489 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
490 #endif
491
492 #ifdef _AIX
getDataRelBase()493 virtual uintptr_t getDataRelBase() {
494 _LIBUNWIND_ABORT("getDataRelBase not implemented");
495 }
496 #endif
497
498 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
get_registers()499 virtual void *get_registers() {
500 _LIBUNWIND_ABORT("get_registers not implemented");
501 }
502 #endif
503 };
504
505 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
506
507 /// \c UnwindCursor contains all state (including all register values) during
508 /// an unwind. This is normally stack-allocated inside a unw_cursor_t.
509 template <typename A, typename R>
510 class UnwindCursor : public AbstractUnwindCursor {
511 typedef typename A::pint_t pint_t;
512 public:
513 UnwindCursor(unw_context_t *context, A &as);
514 UnwindCursor(CONTEXT *context, A &as);
515 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()516 virtual ~UnwindCursor() {}
517 virtual bool validReg(int);
518 virtual unw_word_t getReg(int);
519 virtual void setReg(int, unw_word_t);
520 virtual bool validFloatReg(int);
521 virtual unw_fpreg_t getFloatReg(int);
522 virtual void setFloatReg(int, unw_fpreg_t);
523 virtual int step(bool = false);
524 virtual void getInfo(unw_proc_info_t *);
525 virtual void jumpto();
526 virtual bool isSignalFrame();
527 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
528 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
529 virtual const char *getRegisterName(int num);
530 #ifdef __arm__
531 virtual void saveVFPAsX();
532 #endif
533
getDispatcherContext()534 DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
setDispatcherContext(DISPATCHER_CONTEXT * disp)535 void setDispatcherContext(DISPATCHER_CONTEXT *disp) {
536 _dispContext = *disp;
537 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
538 if (_dispContext.LanguageHandler) {
539 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
540 } else
541 _info.handler = 0;
542 }
543
544 // libunwind does not and should not depend on C++ library which means that we
545 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)546 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
547
548 private:
549
getLastPC() const550 pint_t getLastPC() const { return _dispContext.ControlPc; }
setLastPC(pint_t pc)551 void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)552 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
553 #ifdef __arm__
554 // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit.
555 pc &= ~1U;
556 #endif
557 // If pc points exactly at the end of the range, we might resolve the
558 // next function instead. Decrement pc by 1 to fit inside the current
559 // function.
560 pc -= 1;
561 _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
562 &_dispContext.ImageBase,
563 _dispContext.HistoryTable);
564 *base = _dispContext.ImageBase;
565 return _dispContext.FunctionEntry;
566 }
567 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()568 int stepWithSEHData() {
569 _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
570 _dispContext.ImageBase,
571 _dispContext.ControlPc,
572 _dispContext.FunctionEntry,
573 _dispContext.ContextRecord,
574 &_dispContext.HandlerData,
575 &_dispContext.EstablisherFrame,
576 NULL);
577 // Update some fields of the unwind info now, since we have them.
578 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
579 if (_dispContext.LanguageHandler) {
580 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
581 } else
582 _info.handler = 0;
583 return UNW_STEP_SUCCESS;
584 }
585
586 A &_addressSpace;
587 unw_proc_info_t _info;
588 DISPATCHER_CONTEXT _dispContext;
589 CONTEXT _msContext;
590 UNWIND_HISTORY_TABLE _histTable;
591 bool _unwindInfoMissing;
592 };
593
594
595 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)596 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
597 : _addressSpace(as), _unwindInfoMissing(false) {
598 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
599 "UnwindCursor<> does not fit in unw_cursor_t");
600 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
601 "UnwindCursor<> requires more alignment than unw_cursor_t");
602 memset(&_info, 0, sizeof(_info));
603 memset(&_histTable, 0, sizeof(_histTable));
604 memset(&_dispContext, 0, sizeof(_dispContext));
605 _dispContext.ContextRecord = &_msContext;
606 _dispContext.HistoryTable = &_histTable;
607 // Initialize MS context from ours.
608 R r(context);
609 RtlCaptureContext(&_msContext);
610 _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
611 #if defined(_LIBUNWIND_TARGET_X86_64)
612 _msContext.Rax = r.getRegister(UNW_X86_64_RAX);
613 _msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
614 _msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
615 _msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
616 _msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
617 _msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
618 _msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
619 _msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
620 _msContext.R8 = r.getRegister(UNW_X86_64_R8);
621 _msContext.R9 = r.getRegister(UNW_X86_64_R9);
622 _msContext.R10 = r.getRegister(UNW_X86_64_R10);
623 _msContext.R11 = r.getRegister(UNW_X86_64_R11);
624 _msContext.R12 = r.getRegister(UNW_X86_64_R12);
625 _msContext.R13 = r.getRegister(UNW_X86_64_R13);
626 _msContext.R14 = r.getRegister(UNW_X86_64_R14);
627 _msContext.R15 = r.getRegister(UNW_X86_64_R15);
628 _msContext.Rip = r.getRegister(UNW_REG_IP);
629 union {
630 v128 v;
631 M128A m;
632 } t;
633 t.v = r.getVectorRegister(UNW_X86_64_XMM0);
634 _msContext.Xmm0 = t.m;
635 t.v = r.getVectorRegister(UNW_X86_64_XMM1);
636 _msContext.Xmm1 = t.m;
637 t.v = r.getVectorRegister(UNW_X86_64_XMM2);
638 _msContext.Xmm2 = t.m;
639 t.v = r.getVectorRegister(UNW_X86_64_XMM3);
640 _msContext.Xmm3 = t.m;
641 t.v = r.getVectorRegister(UNW_X86_64_XMM4);
642 _msContext.Xmm4 = t.m;
643 t.v = r.getVectorRegister(UNW_X86_64_XMM5);
644 _msContext.Xmm5 = t.m;
645 t.v = r.getVectorRegister(UNW_X86_64_XMM6);
646 _msContext.Xmm6 = t.m;
647 t.v = r.getVectorRegister(UNW_X86_64_XMM7);
648 _msContext.Xmm7 = t.m;
649 t.v = r.getVectorRegister(UNW_X86_64_XMM8);
650 _msContext.Xmm8 = t.m;
651 t.v = r.getVectorRegister(UNW_X86_64_XMM9);
652 _msContext.Xmm9 = t.m;
653 t.v = r.getVectorRegister(UNW_X86_64_XMM10);
654 _msContext.Xmm10 = t.m;
655 t.v = r.getVectorRegister(UNW_X86_64_XMM11);
656 _msContext.Xmm11 = t.m;
657 t.v = r.getVectorRegister(UNW_X86_64_XMM12);
658 _msContext.Xmm12 = t.m;
659 t.v = r.getVectorRegister(UNW_X86_64_XMM13);
660 _msContext.Xmm13 = t.m;
661 t.v = r.getVectorRegister(UNW_X86_64_XMM14);
662 _msContext.Xmm14 = t.m;
663 t.v = r.getVectorRegister(UNW_X86_64_XMM15);
664 _msContext.Xmm15 = t.m;
665 #elif defined(_LIBUNWIND_TARGET_ARM)
666 _msContext.R0 = r.getRegister(UNW_ARM_R0);
667 _msContext.R1 = r.getRegister(UNW_ARM_R1);
668 _msContext.R2 = r.getRegister(UNW_ARM_R2);
669 _msContext.R3 = r.getRegister(UNW_ARM_R3);
670 _msContext.R4 = r.getRegister(UNW_ARM_R4);
671 _msContext.R5 = r.getRegister(UNW_ARM_R5);
672 _msContext.R6 = r.getRegister(UNW_ARM_R6);
673 _msContext.R7 = r.getRegister(UNW_ARM_R7);
674 _msContext.R8 = r.getRegister(UNW_ARM_R8);
675 _msContext.R9 = r.getRegister(UNW_ARM_R9);
676 _msContext.R10 = r.getRegister(UNW_ARM_R10);
677 _msContext.R11 = r.getRegister(UNW_ARM_R11);
678 _msContext.R12 = r.getRegister(UNW_ARM_R12);
679 _msContext.Sp = r.getRegister(UNW_ARM_SP);
680 _msContext.Lr = r.getRegister(UNW_ARM_LR);
681 _msContext.Pc = r.getRegister(UNW_ARM_IP);
682 for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
683 union {
684 uint64_t w;
685 double d;
686 } d;
687 d.d = r.getFloatRegister(i);
688 _msContext.D[i - UNW_ARM_D0] = d.w;
689 }
690 #elif defined(_LIBUNWIND_TARGET_AARCH64)
691 for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
692 _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
693 _msContext.Sp = r.getRegister(UNW_REG_SP);
694 _msContext.Pc = r.getRegister(UNW_REG_IP);
695 for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
696 _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
697 #endif
698 }
699
700 template <typename A, typename R>
UnwindCursor(CONTEXT * context,A & as)701 UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
702 : _addressSpace(as), _unwindInfoMissing(false) {
703 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
704 "UnwindCursor<> does not fit in unw_cursor_t");
705 memset(&_info, 0, sizeof(_info));
706 memset(&_histTable, 0, sizeof(_histTable));
707 memset(&_dispContext, 0, sizeof(_dispContext));
708 _dispContext.ContextRecord = &_msContext;
709 _dispContext.HistoryTable = &_histTable;
710 _msContext = *context;
711 }
712
713
714 template <typename A, typename R>
validReg(int regNum)715 bool UnwindCursor<A, R>::validReg(int regNum) {
716 if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
717 #if defined(_LIBUNWIND_TARGET_X86_64)
718 if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_RIP) return true;
719 #elif defined(_LIBUNWIND_TARGET_ARM)
720 if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
721 regNum == UNW_ARM_RA_AUTH_CODE)
722 return true;
723 #elif defined(_LIBUNWIND_TARGET_AARCH64)
724 if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
725 #endif
726 return false;
727 }
728
729 template <typename A, typename R>
getReg(int regNum)730 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
731 switch (regNum) {
732 #if defined(_LIBUNWIND_TARGET_X86_64)
733 case UNW_X86_64_RIP:
734 case UNW_REG_IP: return _msContext.Rip;
735 case UNW_X86_64_RAX: return _msContext.Rax;
736 case UNW_X86_64_RDX: return _msContext.Rdx;
737 case UNW_X86_64_RCX: return _msContext.Rcx;
738 case UNW_X86_64_RBX: return _msContext.Rbx;
739 case UNW_REG_SP:
740 case UNW_X86_64_RSP: return _msContext.Rsp;
741 case UNW_X86_64_RBP: return _msContext.Rbp;
742 case UNW_X86_64_RSI: return _msContext.Rsi;
743 case UNW_X86_64_RDI: return _msContext.Rdi;
744 case UNW_X86_64_R8: return _msContext.R8;
745 case UNW_X86_64_R9: return _msContext.R9;
746 case UNW_X86_64_R10: return _msContext.R10;
747 case UNW_X86_64_R11: return _msContext.R11;
748 case UNW_X86_64_R12: return _msContext.R12;
749 case UNW_X86_64_R13: return _msContext.R13;
750 case UNW_X86_64_R14: return _msContext.R14;
751 case UNW_X86_64_R15: return _msContext.R15;
752 #elif defined(_LIBUNWIND_TARGET_ARM)
753 case UNW_ARM_R0: return _msContext.R0;
754 case UNW_ARM_R1: return _msContext.R1;
755 case UNW_ARM_R2: return _msContext.R2;
756 case UNW_ARM_R3: return _msContext.R3;
757 case UNW_ARM_R4: return _msContext.R4;
758 case UNW_ARM_R5: return _msContext.R5;
759 case UNW_ARM_R6: return _msContext.R6;
760 case UNW_ARM_R7: return _msContext.R7;
761 case UNW_ARM_R8: return _msContext.R8;
762 case UNW_ARM_R9: return _msContext.R9;
763 case UNW_ARM_R10: return _msContext.R10;
764 case UNW_ARM_R11: return _msContext.R11;
765 case UNW_ARM_R12: return _msContext.R12;
766 case UNW_REG_SP:
767 case UNW_ARM_SP: return _msContext.Sp;
768 case UNW_ARM_LR: return _msContext.Lr;
769 case UNW_REG_IP:
770 case UNW_ARM_IP: return _msContext.Pc;
771 #elif defined(_LIBUNWIND_TARGET_AARCH64)
772 case UNW_REG_SP: return _msContext.Sp;
773 case UNW_REG_IP: return _msContext.Pc;
774 default: return _msContext.X[regNum - UNW_AARCH64_X0];
775 #endif
776 }
777 _LIBUNWIND_ABORT("unsupported register");
778 }
779
780 template <typename A, typename R>
setReg(int regNum,unw_word_t value)781 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
782 switch (regNum) {
783 #if defined(_LIBUNWIND_TARGET_X86_64)
784 case UNW_X86_64_RIP:
785 case UNW_REG_IP: _msContext.Rip = value; break;
786 case UNW_X86_64_RAX: _msContext.Rax = value; break;
787 case UNW_X86_64_RDX: _msContext.Rdx = value; break;
788 case UNW_X86_64_RCX: _msContext.Rcx = value; break;
789 case UNW_X86_64_RBX: _msContext.Rbx = value; break;
790 case UNW_REG_SP:
791 case UNW_X86_64_RSP: _msContext.Rsp = value; break;
792 case UNW_X86_64_RBP: _msContext.Rbp = value; break;
793 case UNW_X86_64_RSI: _msContext.Rsi = value; break;
794 case UNW_X86_64_RDI: _msContext.Rdi = value; break;
795 case UNW_X86_64_R8: _msContext.R8 = value; break;
796 case UNW_X86_64_R9: _msContext.R9 = value; break;
797 case UNW_X86_64_R10: _msContext.R10 = value; break;
798 case UNW_X86_64_R11: _msContext.R11 = value; break;
799 case UNW_X86_64_R12: _msContext.R12 = value; break;
800 case UNW_X86_64_R13: _msContext.R13 = value; break;
801 case UNW_X86_64_R14: _msContext.R14 = value; break;
802 case UNW_X86_64_R15: _msContext.R15 = value; break;
803 #elif defined(_LIBUNWIND_TARGET_ARM)
804 case UNW_ARM_R0: _msContext.R0 = value; break;
805 case UNW_ARM_R1: _msContext.R1 = value; break;
806 case UNW_ARM_R2: _msContext.R2 = value; break;
807 case UNW_ARM_R3: _msContext.R3 = value; break;
808 case UNW_ARM_R4: _msContext.R4 = value; break;
809 case UNW_ARM_R5: _msContext.R5 = value; break;
810 case UNW_ARM_R6: _msContext.R6 = value; break;
811 case UNW_ARM_R7: _msContext.R7 = value; break;
812 case UNW_ARM_R8: _msContext.R8 = value; break;
813 case UNW_ARM_R9: _msContext.R9 = value; break;
814 case UNW_ARM_R10: _msContext.R10 = value; break;
815 case UNW_ARM_R11: _msContext.R11 = value; break;
816 case UNW_ARM_R12: _msContext.R12 = value; break;
817 case UNW_REG_SP:
818 case UNW_ARM_SP: _msContext.Sp = value; break;
819 case UNW_ARM_LR: _msContext.Lr = value; break;
820 case UNW_REG_IP:
821 case UNW_ARM_IP: _msContext.Pc = value; break;
822 #elif defined(_LIBUNWIND_TARGET_AARCH64)
823 case UNW_REG_SP: _msContext.Sp = value; break;
824 case UNW_REG_IP: _msContext.Pc = value; break;
825 case UNW_AARCH64_X0:
826 case UNW_AARCH64_X1:
827 case UNW_AARCH64_X2:
828 case UNW_AARCH64_X3:
829 case UNW_AARCH64_X4:
830 case UNW_AARCH64_X5:
831 case UNW_AARCH64_X6:
832 case UNW_AARCH64_X7:
833 case UNW_AARCH64_X8:
834 case UNW_AARCH64_X9:
835 case UNW_AARCH64_X10:
836 case UNW_AARCH64_X11:
837 case UNW_AARCH64_X12:
838 case UNW_AARCH64_X13:
839 case UNW_AARCH64_X14:
840 case UNW_AARCH64_X15:
841 case UNW_AARCH64_X16:
842 case UNW_AARCH64_X17:
843 case UNW_AARCH64_X18:
844 case UNW_AARCH64_X19:
845 case UNW_AARCH64_X20:
846 case UNW_AARCH64_X21:
847 case UNW_AARCH64_X22:
848 case UNW_AARCH64_X23:
849 case UNW_AARCH64_X24:
850 case UNW_AARCH64_X25:
851 case UNW_AARCH64_X26:
852 case UNW_AARCH64_X27:
853 case UNW_AARCH64_X28:
854 case UNW_AARCH64_FP:
855 case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
856 #endif
857 default:
858 _LIBUNWIND_ABORT("unsupported register");
859 }
860 }
861
862 template <typename A, typename R>
validFloatReg(int regNum)863 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
864 #if defined(_LIBUNWIND_TARGET_ARM)
865 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
866 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
867 #elif defined(_LIBUNWIND_TARGET_AARCH64)
868 if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
869 #else
870 (void)regNum;
871 #endif
872 return false;
873 }
874
875 template <typename A, typename R>
getFloatReg(int regNum)876 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
877 #if defined(_LIBUNWIND_TARGET_ARM)
878 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
879 union {
880 uint32_t w;
881 float f;
882 } d;
883 d.w = _msContext.S[regNum - UNW_ARM_S0];
884 return d.f;
885 }
886 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
887 union {
888 uint64_t w;
889 double d;
890 } d;
891 d.w = _msContext.D[regNum - UNW_ARM_D0];
892 return d.d;
893 }
894 _LIBUNWIND_ABORT("unsupported float register");
895 #elif defined(_LIBUNWIND_TARGET_AARCH64)
896 return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
897 #else
898 (void)regNum;
899 _LIBUNWIND_ABORT("float registers unimplemented");
900 #endif
901 }
902
903 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)904 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
905 #if defined(_LIBUNWIND_TARGET_ARM)
906 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
907 union {
908 uint32_t w;
909 float f;
910 } d;
911 d.f = (float)value;
912 _msContext.S[regNum - UNW_ARM_S0] = d.w;
913 }
914 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
915 union {
916 uint64_t w;
917 double d;
918 } d;
919 d.d = value;
920 _msContext.D[regNum - UNW_ARM_D0] = d.w;
921 }
922 _LIBUNWIND_ABORT("unsupported float register");
923 #elif defined(_LIBUNWIND_TARGET_AARCH64)
924 _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
925 #else
926 (void)regNum;
927 (void)value;
928 _LIBUNWIND_ABORT("float registers unimplemented");
929 #endif
930 }
931
jumpto()932 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
933 RtlRestoreContext(&_msContext, nullptr);
934 }
935
936 #ifdef __arm__
saveVFPAsX()937 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
938 #endif
939
940 template <typename A, typename R>
getRegisterName(int regNum)941 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
942 return R::getRegisterName(regNum);
943 }
944
isSignalFrame()945 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
946 return false;
947 }
948
949 #else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
950
951 /// UnwindCursor contains all state (including all register values) during
952 /// an unwind. This is normally stack allocated inside a unw_cursor_t.
953 template <typename A, typename R>
954 class UnwindCursor : public AbstractUnwindCursor{
955 typedef typename A::pint_t pint_t;
956 public:
957 UnwindCursor(unw_context_t *context, A &as);
958 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()959 virtual ~UnwindCursor() {}
960 virtual bool validReg(int);
961 virtual unw_word_t getReg(int);
962 virtual void setReg(int, unw_word_t);
963 virtual bool validFloatReg(int);
964 virtual unw_fpreg_t getFloatReg(int);
965 virtual void setFloatReg(int, unw_fpreg_t);
966 virtual int step(bool stage2 = false);
967 virtual void getInfo(unw_proc_info_t *);
968 virtual void jumpto();
969 virtual bool isSignalFrame();
970 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
971 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
972 virtual const char *getRegisterName(int num);
973 #ifdef __arm__
974 virtual void saveVFPAsX();
975 #endif
976
977 #ifdef _AIX
978 virtual uintptr_t getDataRelBase();
979 #endif
980
981 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
get_registers()982 virtual void *get_registers() { return &_registers; }
983 #endif
984
985 // libunwind does not and should not depend on C++ library which means that we
986 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)987 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
988
989 private:
990
991 #if defined(_LIBUNWIND_ARM_EHABI)
992 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s);
993
stepWithEHABI()994 int stepWithEHABI() {
995 size_t len = 0;
996 size_t off = 0;
997 // FIXME: Calling decode_eht_entry() here is violating the libunwind
998 // abstraction layer.
999 const uint32_t *ehtp =
1000 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
1001 &off, &len);
1002 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
1003 _URC_CONTINUE_UNWIND)
1004 return UNW_STEP_END;
1005 return UNW_STEP_SUCCESS;
1006 }
1007 #endif
1008
1009 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
setInfoForSigReturn()1010 bool setInfoForSigReturn() {
1011 R dummy;
1012 return setInfoForSigReturn(dummy);
1013 }
stepThroughSigReturn()1014 int stepThroughSigReturn() {
1015 R dummy;
1016 return stepThroughSigReturn(dummy);
1017 }
1018 bool isReadableAddr(const pint_t addr) const;
1019 #if defined(_LIBUNWIND_TARGET_AARCH64)
1020 bool setInfoForSigReturn(Registers_arm64 &);
1021 int stepThroughSigReturn(Registers_arm64 &);
1022 #endif
1023 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
1024 bool setInfoForSigReturn(Registers_loongarch &);
1025 int stepThroughSigReturn(Registers_loongarch &);
1026 #endif
1027 #if defined(_LIBUNWIND_TARGET_RISCV)
1028 bool setInfoForSigReturn(Registers_riscv &);
1029 int stepThroughSigReturn(Registers_riscv &);
1030 #endif
1031 #if defined(_LIBUNWIND_TARGET_S390X)
1032 bool setInfoForSigReturn(Registers_s390x &);
1033 int stepThroughSigReturn(Registers_s390x &);
1034 #endif
setInfoForSigReturn(Registers &)1035 template <typename Registers> bool setInfoForSigReturn(Registers &) {
1036 return false;
1037 }
stepThroughSigReturn(Registers &)1038 template <typename Registers> int stepThroughSigReturn(Registers &) {
1039 return UNW_STEP_END;
1040 }
1041 #elif defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
1042 bool setInfoForSigReturn();
1043 int stepThroughSigReturn();
1044 #endif
1045
1046 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1047 bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1048 const typename CFI_Parser<A>::CIE_Info &cieInfo,
1049 pint_t pc, uintptr_t dso_base);
1050 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s,
1051 uint32_t fdeSectionOffsetHint=0);
stepWithDwarfFDE(bool stage2)1052 int stepWithDwarfFDE(bool stage2) {
1053 return DwarfInstructions<A, R>::stepWithDwarf(
1054 _addressSpace, (pint_t)this->getReg(UNW_REG_IP),
1055 (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2);
1056 }
1057 #endif
1058
1059 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1060 bool getInfoFromCompactEncodingSection(pint_t pc,
1061 const UnwindInfoSections §s);
stepWithCompactEncoding(bool stage2=false)1062 int stepWithCompactEncoding(bool stage2 = false) {
1063 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1064 if ( compactSaysUseDwarf() )
1065 return stepWithDwarfFDE(stage2);
1066 #endif
1067 R dummy;
1068 return stepWithCompactEncoding(dummy);
1069 }
1070
1071 #if defined(_LIBUNWIND_TARGET_X86_64)
stepWithCompactEncoding(Registers_x86_64 &)1072 int stepWithCompactEncoding(Registers_x86_64 &) {
1073 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
1074 _info.format, _info.start_ip, _addressSpace, _registers);
1075 }
1076 #endif
1077
1078 #if defined(_LIBUNWIND_TARGET_I386)
stepWithCompactEncoding(Registers_x86 &)1079 int stepWithCompactEncoding(Registers_x86 &) {
1080 return CompactUnwinder_x86<A>::stepWithCompactEncoding(
1081 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
1082 }
1083 #endif
1084
1085 #if defined(_LIBUNWIND_TARGET_PPC)
stepWithCompactEncoding(Registers_ppc &)1086 int stepWithCompactEncoding(Registers_ppc &) {
1087 return UNW_EINVAL;
1088 }
1089 #endif
1090
1091 #if defined(_LIBUNWIND_TARGET_PPC64)
stepWithCompactEncoding(Registers_ppc64 &)1092 int stepWithCompactEncoding(Registers_ppc64 &) {
1093 return UNW_EINVAL;
1094 }
1095 #endif
1096
1097
1098 #if defined(_LIBUNWIND_TARGET_AARCH64)
stepWithCompactEncoding(Registers_arm64 &)1099 int stepWithCompactEncoding(Registers_arm64 &) {
1100 return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
1101 _info.format, _info.start_ip, _addressSpace, _registers);
1102 }
1103 #endif
1104
1105 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
stepWithCompactEncoding(Registers_mips_o32 &)1106 int stepWithCompactEncoding(Registers_mips_o32 &) {
1107 return UNW_EINVAL;
1108 }
1109 #endif
1110
1111 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
stepWithCompactEncoding(Registers_mips_newabi &)1112 int stepWithCompactEncoding(Registers_mips_newabi &) {
1113 return UNW_EINVAL;
1114 }
1115 #endif
1116
1117 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
stepWithCompactEncoding(Registers_loongarch &)1118 int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; }
1119 #endif
1120
1121 #if defined(_LIBUNWIND_TARGET_SPARC)
stepWithCompactEncoding(Registers_sparc &)1122 int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
1123 #endif
1124
1125 #if defined(_LIBUNWIND_TARGET_SPARC64)
stepWithCompactEncoding(Registers_sparc64 &)1126 int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
1127 #endif
1128
1129 #if defined (_LIBUNWIND_TARGET_RISCV)
stepWithCompactEncoding(Registers_riscv &)1130 int stepWithCompactEncoding(Registers_riscv &) {
1131 return UNW_EINVAL;
1132 }
1133 #endif
1134
compactSaysUseDwarf(uint32_t * offset=NULL) const1135 bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
1136 R dummy;
1137 return compactSaysUseDwarf(dummy, offset);
1138 }
1139
1140 #if defined(_LIBUNWIND_TARGET_X86_64)
compactSaysUseDwarf(Registers_x86_64 &,uint32_t * offset) const1141 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
1142 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
1143 if (offset)
1144 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
1145 return true;
1146 }
1147 return false;
1148 }
1149 #endif
1150
1151 #if defined(_LIBUNWIND_TARGET_I386)
compactSaysUseDwarf(Registers_x86 &,uint32_t * offset) const1152 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
1153 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
1154 if (offset)
1155 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
1156 return true;
1157 }
1158 return false;
1159 }
1160 #endif
1161
1162 #if defined(_LIBUNWIND_TARGET_PPC)
compactSaysUseDwarf(Registers_ppc &,uint32_t *) const1163 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
1164 return true;
1165 }
1166 #endif
1167
1168 #if defined(_LIBUNWIND_TARGET_PPC64)
compactSaysUseDwarf(Registers_ppc64 &,uint32_t *) const1169 bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
1170 return true;
1171 }
1172 #endif
1173
1174 #if defined(_LIBUNWIND_TARGET_AARCH64)
compactSaysUseDwarf(Registers_arm64 &,uint32_t * offset) const1175 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
1176 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
1177 if (offset)
1178 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
1179 return true;
1180 }
1181 return false;
1182 }
1183 #endif
1184
1185 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
compactSaysUseDwarf(Registers_mips_o32 &,uint32_t *) const1186 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
1187 return true;
1188 }
1189 #endif
1190
1191 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
compactSaysUseDwarf(Registers_mips_newabi &,uint32_t *) const1192 bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
1193 return true;
1194 }
1195 #endif
1196
1197 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
compactSaysUseDwarf(Registers_loongarch &,uint32_t *) const1198 bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const {
1199 return true;
1200 }
1201 #endif
1202
1203 #if defined(_LIBUNWIND_TARGET_SPARC)
compactSaysUseDwarf(Registers_sparc &,uint32_t *) const1204 bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
1205 #endif
1206
1207 #if defined(_LIBUNWIND_TARGET_SPARC64)
compactSaysUseDwarf(Registers_sparc64 &,uint32_t *) const1208 bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
1209 return true;
1210 }
1211 #endif
1212
1213 #if defined (_LIBUNWIND_TARGET_RISCV)
compactSaysUseDwarf(Registers_riscv &,uint32_t *) const1214 bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
1215 return true;
1216 }
1217 #endif
1218
1219 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1220
1221 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
dwarfEncoding() const1222 compact_unwind_encoding_t dwarfEncoding() const {
1223 R dummy;
1224 return dwarfEncoding(dummy);
1225 }
1226
1227 #if defined(_LIBUNWIND_TARGET_X86_64)
dwarfEncoding(Registers_x86_64 &) const1228 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
1229 return UNWIND_X86_64_MODE_DWARF;
1230 }
1231 #endif
1232
1233 #if defined(_LIBUNWIND_TARGET_I386)
dwarfEncoding(Registers_x86 &) const1234 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
1235 return UNWIND_X86_MODE_DWARF;
1236 }
1237 #endif
1238
1239 #if defined(_LIBUNWIND_TARGET_PPC)
dwarfEncoding(Registers_ppc &) const1240 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
1241 return 0;
1242 }
1243 #endif
1244
1245 #if defined(_LIBUNWIND_TARGET_PPC64)
dwarfEncoding(Registers_ppc64 &) const1246 compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
1247 return 0;
1248 }
1249 #endif
1250
1251 #if defined(_LIBUNWIND_TARGET_AARCH64)
dwarfEncoding(Registers_arm64 &) const1252 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
1253 return UNWIND_ARM64_MODE_DWARF;
1254 }
1255 #endif
1256
1257 #if defined(_LIBUNWIND_TARGET_ARM)
dwarfEncoding(Registers_arm &) const1258 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
1259 return 0;
1260 }
1261 #endif
1262
1263 #if defined (_LIBUNWIND_TARGET_OR1K)
dwarfEncoding(Registers_or1k &) const1264 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
1265 return 0;
1266 }
1267 #endif
1268
1269 #if defined (_LIBUNWIND_TARGET_HEXAGON)
dwarfEncoding(Registers_hexagon &) const1270 compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
1271 return 0;
1272 }
1273 #endif
1274
1275 #if defined (_LIBUNWIND_TARGET_MIPS_O32)
dwarfEncoding(Registers_mips_o32 &) const1276 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
1277 return 0;
1278 }
1279 #endif
1280
1281 #if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
dwarfEncoding(Registers_mips_newabi &) const1282 compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
1283 return 0;
1284 }
1285 #endif
1286
1287 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
dwarfEncoding(Registers_loongarch &) const1288 compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const {
1289 return 0;
1290 }
1291 #endif
1292
1293 #if defined(_LIBUNWIND_TARGET_SPARC)
dwarfEncoding(Registers_sparc &) const1294 compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
1295 #endif
1296
1297 #if defined(_LIBUNWIND_TARGET_SPARC64)
dwarfEncoding(Registers_sparc64 &) const1298 compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
1299 return 0;
1300 }
1301 #endif
1302
1303 #if defined (_LIBUNWIND_TARGET_RISCV)
dwarfEncoding(Registers_riscv &) const1304 compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
1305 return 0;
1306 }
1307 #endif
1308
1309 #if defined (_LIBUNWIND_TARGET_S390X)
dwarfEncoding(Registers_s390x &) const1310 compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const {
1311 return 0;
1312 }
1313 #endif
1314
1315 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1316
1317 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1318 // For runtime environments using SEH unwind data without Windows runtime
1319 // support.
getLastPC() const1320 pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
setLastPC(pint_t pc)1321 void setLastPC(pint_t pc) { /* FIXME: Implement */ }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)1322 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
1323 /* FIXME: Implement */
1324 *base = 0;
1325 return nullptr;
1326 }
1327 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()1328 int stepWithSEHData() { /* FIXME: Implement */ return 0; }
1329 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1330
1331 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1332 bool getInfoFromTBTable(pint_t pc, R ®isters);
1333 int stepWithTBTable(pint_t pc, tbtable *TBTable, R ®isters,
1334 bool &isSignalFrame);
stepWithTBTableData()1335 int stepWithTBTableData() {
1336 return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
1337 reinterpret_cast<tbtable *>(_info.unwind_info),
1338 _registers, _isSignalFrame);
1339 }
1340 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1341
1342 A &_addressSpace;
1343 R _registers;
1344 unw_proc_info_t _info;
1345 bool _unwindInfoMissing;
1346 bool _isSignalFrame;
1347 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
1348 defined(_LIBUNWIND_TARGET_HAIKU)
1349 bool _isSigReturn = false;
1350 #endif
1351 };
1352
1353
1354 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)1355 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
1356 : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
1357 _isSignalFrame(false) {
1358 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
1359 "UnwindCursor<> does not fit in unw_cursor_t");
1360 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
1361 "UnwindCursor<> requires more alignment than unw_cursor_t");
1362 memset(&_info, 0, sizeof(_info));
1363 }
1364
1365 template <typename A, typename R>
UnwindCursor(A & as,void *)1366 UnwindCursor<A, R>::UnwindCursor(A &as, void *)
1367 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
1368 memset(&_info, 0, sizeof(_info));
1369 // FIXME
1370 // fill in _registers from thread arg
1371 }
1372
1373
1374 template <typename A, typename R>
validReg(int regNum)1375 bool UnwindCursor<A, R>::validReg(int regNum) {
1376 return _registers.validRegister(regNum);
1377 }
1378
1379 template <typename A, typename R>
getReg(int regNum)1380 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
1381 return _registers.getRegister(regNum);
1382 }
1383
1384 template <typename A, typename R>
setReg(int regNum,unw_word_t value)1385 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
1386 _registers.setRegister(regNum, (typename A::pint_t)value);
1387 }
1388
1389 template <typename A, typename R>
validFloatReg(int regNum)1390 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
1391 return _registers.validFloatRegister(regNum);
1392 }
1393
1394 template <typename A, typename R>
getFloatReg(int regNum)1395 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
1396 return _registers.getFloatRegister(regNum);
1397 }
1398
1399 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)1400 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
1401 _registers.setFloatRegister(regNum, value);
1402 }
1403
jumpto()1404 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
1405 _registers.jumpto();
1406 }
1407
1408 #ifdef __arm__
saveVFPAsX()1409 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
1410 _registers.saveVFPAsX();
1411 }
1412 #endif
1413
1414 #ifdef _AIX
1415 template <typename A, typename R>
getDataRelBase()1416 uintptr_t UnwindCursor<A, R>::getDataRelBase() {
1417 return reinterpret_cast<uintptr_t>(_info.extra);
1418 }
1419 #endif
1420
1421 template <typename A, typename R>
getRegisterName(int regNum)1422 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
1423 return _registers.getRegisterName(regNum);
1424 }
1425
isSignalFrame()1426 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
1427 return _isSignalFrame;
1428 }
1429
1430 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1431
1432 #if defined(_LIBUNWIND_ARM_EHABI)
1433 template<typename A>
1434 struct EHABISectionIterator {
1435 typedef EHABISectionIterator _Self;
1436
1437 typedef typename A::pint_t value_type;
1438 typedef typename A::pint_t* pointer;
1439 typedef typename A::pint_t& reference;
1440 typedef size_t size_type;
1441 typedef size_t difference_type;
1442
beginlibunwind::EHABISectionIterator1443 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
1444 return _Self(addressSpace, sects, 0);
1445 }
endlibunwind::EHABISectionIterator1446 static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
1447 return _Self(addressSpace, sects,
1448 sects.arm_section_length / sizeof(EHABIIndexEntry));
1449 }
1450
EHABISectionIteratorlibunwind::EHABISectionIterator1451 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
1452 : _i(i), _addressSpace(&addressSpace), _sects(§s) {}
1453
operator ++libunwind::EHABISectionIterator1454 _Self& operator++() { ++_i; return *this; }
operator +=libunwind::EHABISectionIterator1455 _Self& operator+=(size_t a) { _i += a; return *this; }
operator --libunwind::EHABISectionIterator1456 _Self& operator--() { assert(_i > 0); --_i; return *this; }
operator -=libunwind::EHABISectionIterator1457 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
1458
operator +libunwind::EHABISectionIterator1459 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
operator -libunwind::EHABISectionIterator1460 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
1461
operator -libunwind::EHABISectionIterator1462 size_t operator-(const _Self& other) const { return _i - other._i; }
1463
operator ==libunwind::EHABISectionIterator1464 bool operator==(const _Self& other) const {
1465 assert(_addressSpace == other._addressSpace);
1466 assert(_sects == other._sects);
1467 return _i == other._i;
1468 }
1469
operator !=libunwind::EHABISectionIterator1470 bool operator!=(const _Self& other) const {
1471 assert(_addressSpace == other._addressSpace);
1472 assert(_sects == other._sects);
1473 return _i != other._i;
1474 }
1475
operator *libunwind::EHABISectionIterator1476 typename A::pint_t operator*() const { return functionAddress(); }
1477
functionAddresslibunwind::EHABISectionIterator1478 typename A::pint_t functionAddress() const {
1479 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1480 EHABIIndexEntry, _i, functionOffset);
1481 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
1482 }
1483
dataAddresslibunwind::EHABISectionIterator1484 typename A::pint_t dataAddress() {
1485 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1486 EHABIIndexEntry, _i, data);
1487 return indexAddr;
1488 }
1489
1490 private:
1491 size_t _i;
1492 A* _addressSpace;
1493 const UnwindInfoSections* _sects;
1494 };
1495
1496 namespace {
1497
1498 template <typename A>
EHABISectionUpperBound(EHABISectionIterator<A> first,EHABISectionIterator<A> last,typename A::pint_t value)1499 EHABISectionIterator<A> EHABISectionUpperBound(
1500 EHABISectionIterator<A> first,
1501 EHABISectionIterator<A> last,
1502 typename A::pint_t value) {
1503 size_t len = last - first;
1504 while (len > 0) {
1505 size_t l2 = len / 2;
1506 EHABISectionIterator<A> m = first + l2;
1507 if (value < *m) {
1508 len = l2;
1509 } else {
1510 first = ++m;
1511 len -= l2 + 1;
1512 }
1513 }
1514 return first;
1515 }
1516
1517 }
1518
1519 template <typename A, typename R>
getInfoFromEHABISection(pint_t pc,const UnwindInfoSections & sects)1520 bool UnwindCursor<A, R>::getInfoFromEHABISection(
1521 pint_t pc,
1522 const UnwindInfoSections §s) {
1523 EHABISectionIterator<A> begin =
1524 EHABISectionIterator<A>::begin(_addressSpace, sects);
1525 EHABISectionIterator<A> end =
1526 EHABISectionIterator<A>::end(_addressSpace, sects);
1527 if (begin == end)
1528 return false;
1529
1530 EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
1531 if (itNextPC == begin)
1532 return false;
1533 EHABISectionIterator<A> itThisPC = itNextPC - 1;
1534
1535 pint_t thisPC = itThisPC.functionAddress();
1536 // If an exception is thrown from a function, corresponding to the last entry
1537 // in the table, we don't really know the function extent and have to choose a
1538 // value for nextPC. Choosing max() will allow the range check during trace to
1539 // succeed.
1540 pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
1541 pint_t indexDataAddr = itThisPC.dataAddress();
1542
1543 if (indexDataAddr == 0)
1544 return false;
1545
1546 uint32_t indexData = _addressSpace.get32(indexDataAddr);
1547 if (indexData == UNW_EXIDX_CANTUNWIND)
1548 return false;
1549
1550 // If the high bit is set, the exception handling table entry is inline inside
1551 // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
1552 // the table points at an offset in the exception handling table (section 5
1553 // EHABI).
1554 pint_t exceptionTableAddr;
1555 uint32_t exceptionTableData;
1556 bool isSingleWordEHT;
1557 if (indexData & 0x80000000) {
1558 exceptionTableAddr = indexDataAddr;
1559 // TODO(ajwong): Should this data be 0?
1560 exceptionTableData = indexData;
1561 isSingleWordEHT = true;
1562 } else {
1563 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
1564 exceptionTableData = _addressSpace.get32(exceptionTableAddr);
1565 isSingleWordEHT = false;
1566 }
1567
1568 // Now we know the 3 things:
1569 // exceptionTableAddr -- exception handler table entry.
1570 // exceptionTableData -- the data inside the first word of the eht entry.
1571 // isSingleWordEHT -- whether the entry is in the index.
1572 unw_word_t personalityRoutine = 0xbadf00d;
1573 bool scope32 = false;
1574 uintptr_t lsda;
1575
1576 // If the high bit in the exception handling table entry is set, the entry is
1577 // in compact form (section 6.3 EHABI).
1578 if (exceptionTableData & 0x80000000) {
1579 // Grab the index of the personality routine from the compact form.
1580 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
1581 uint32_t extraWords = 0;
1582 switch (choice) {
1583 case 0:
1584 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
1585 extraWords = 0;
1586 scope32 = false;
1587 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
1588 break;
1589 case 1:
1590 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
1591 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1592 scope32 = false;
1593 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1594 break;
1595 case 2:
1596 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
1597 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1598 scope32 = true;
1599 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1600 break;
1601 default:
1602 _LIBUNWIND_ABORT("unknown personality routine");
1603 return false;
1604 }
1605
1606 if (isSingleWordEHT) {
1607 if (extraWords != 0) {
1608 _LIBUNWIND_ABORT("index inlined table detected but pr function "
1609 "requires extra words");
1610 return false;
1611 }
1612 }
1613 } else {
1614 pint_t personalityAddr =
1615 exceptionTableAddr + signExtendPrel31(exceptionTableData);
1616 personalityRoutine = personalityAddr;
1617
1618 // ARM EHABI # 6.2, # 9.2
1619 //
1620 // +---- ehtp
1621 // v
1622 // +--------------------------------------+
1623 // | +--------+--------+--------+-------+ |
1624 // | |0| prel31 to personalityRoutine | |
1625 // | +--------+--------+--------+-------+ |
1626 // | | N | unwind opcodes | | <-- UnwindData
1627 // | +--------+--------+--------+-------+ |
1628 // | | Word 2 unwind opcodes | |
1629 // | +--------+--------+--------+-------+ |
1630 // | ... |
1631 // | +--------+--------+--------+-------+ |
1632 // | | Word N unwind opcodes | |
1633 // | +--------+--------+--------+-------+ |
1634 // | | LSDA | | <-- lsda
1635 // | | ... | |
1636 // | +--------+--------+--------+-------+ |
1637 // +--------------------------------------+
1638
1639 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
1640 uint32_t FirstDataWord = *UnwindData;
1641 size_t N = ((FirstDataWord >> 24) & 0xff);
1642 size_t NDataWords = N + 1;
1643 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
1644 }
1645
1646 _info.start_ip = thisPC;
1647 _info.end_ip = nextPC;
1648 _info.handler = personalityRoutine;
1649 _info.unwind_info = exceptionTableAddr;
1650 _info.lsda = lsda;
1651 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
1652 _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum?
1653
1654 return true;
1655 }
1656 #endif
1657
1658 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1659 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)1660 bool UnwindCursor<A, R>::getInfoFromFdeCie(
1661 const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1662 const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc,
1663 uintptr_t dso_base) {
1664 typename CFI_Parser<A>::PrologInfo prolog;
1665 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
1666 R::getArch(), &prolog)) {
1667 // Save off parsed FDE info
1668 _info.start_ip = fdeInfo.pcStart;
1669 _info.end_ip = fdeInfo.pcEnd;
1670 _info.lsda = fdeInfo.lsda;
1671 _info.handler = cieInfo.personality;
1672 // Some frameless functions need SP altered when resuming in function, so
1673 // propagate spExtraArgSize.
1674 _info.gp = prolog.spExtraArgSize;
1675 _info.flags = 0;
1676 _info.format = dwarfEncoding();
1677 _info.unwind_info = fdeInfo.fdeStart;
1678 _info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength);
1679 _info.extra = static_cast<unw_word_t>(dso_base);
1680 return true;
1681 }
1682 return false;
1683 }
1684
1685 template <typename A, typename R>
getInfoFromDwarfSection(pint_t pc,const UnwindInfoSections & sects,uint32_t fdeSectionOffsetHint)1686 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
1687 const UnwindInfoSections §s,
1688 uint32_t fdeSectionOffsetHint) {
1689 typename CFI_Parser<A>::FDE_Info fdeInfo;
1690 typename CFI_Parser<A>::CIE_Info cieInfo;
1691 bool foundFDE = false;
1692 bool foundInCache = false;
1693 // If compact encoding table gave offset into dwarf section, go directly there
1694 if (fdeSectionOffsetHint != 0) {
1695 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1696 sects.dwarf_section_length,
1697 sects.dwarf_section + fdeSectionOffsetHint,
1698 &fdeInfo, &cieInfo);
1699 }
1700 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1701 if (!foundFDE && (sects.dwarf_index_section != 0)) {
1702 foundFDE = EHHeaderParser<A>::findFDE(
1703 _addressSpace, pc, sects.dwarf_index_section,
1704 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
1705 }
1706 #endif
1707 if (!foundFDE) {
1708 // otherwise, search cache of previously found FDEs.
1709 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
1710 if (cachedFDE != 0) {
1711 foundFDE =
1712 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1713 sects.dwarf_section_length,
1714 cachedFDE, &fdeInfo, &cieInfo);
1715 foundInCache = foundFDE;
1716 }
1717 }
1718 if (!foundFDE) {
1719 // Still not found, do full scan of __eh_frame section.
1720 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1721 sects.dwarf_section_length, 0,
1722 &fdeInfo, &cieInfo);
1723 }
1724 if (foundFDE) {
1725 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) {
1726 // Add to cache (to make next lookup faster) if we had no hint
1727 // and there was no index.
1728 if (!foundInCache && (fdeSectionOffsetHint == 0)) {
1729 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1730 if (sects.dwarf_index_section == 0)
1731 #endif
1732 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
1733 fdeInfo.fdeStart);
1734 }
1735 return true;
1736 }
1737 }
1738 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
1739 return false;
1740 }
1741 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1742
1743
1744 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1745 template <typename A, typename R>
getInfoFromCompactEncodingSection(pint_t pc,const UnwindInfoSections & sects)1746 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
1747 const UnwindInfoSections §s) {
1748 const bool log = false;
1749 if (log)
1750 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
1751 (uint64_t)pc, (uint64_t)sects.dso_base);
1752
1753 const UnwindSectionHeader<A> sectionHeader(_addressSpace,
1754 sects.compact_unwind_section);
1755 if (sectionHeader.version() != UNWIND_SECTION_VERSION)
1756 return false;
1757
1758 // do a binary search of top level index to find page with unwind info
1759 pint_t targetFunctionOffset = pc - sects.dso_base;
1760 const UnwindSectionIndexArray<A> topIndex(_addressSpace,
1761 sects.compact_unwind_section
1762 + sectionHeader.indexSectionOffset());
1763 uint32_t low = 0;
1764 uint32_t high = sectionHeader.indexCount();
1765 uint32_t last = high - 1;
1766 while (low < high) {
1767 uint32_t mid = (low + high) / 2;
1768 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
1769 //mid, low, high, topIndex.functionOffset(mid));
1770 if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
1771 if ((mid == last) ||
1772 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
1773 low = mid;
1774 break;
1775 } else {
1776 low = mid + 1;
1777 }
1778 } else {
1779 high = mid;
1780 }
1781 }
1782 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
1783 const uint32_t firstLevelNextPageFunctionOffset =
1784 topIndex.functionOffset(low + 1);
1785 const pint_t secondLevelAddr =
1786 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
1787 const pint_t lsdaArrayStartAddr =
1788 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
1789 const pint_t lsdaArrayEndAddr =
1790 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
1791 if (log)
1792 fprintf(stderr, "\tfirst level search for result index=%d "
1793 "to secondLevelAddr=0x%llX\n",
1794 low, (uint64_t) secondLevelAddr);
1795 // do a binary search of second level page index
1796 uint32_t encoding = 0;
1797 pint_t funcStart = 0;
1798 pint_t funcEnd = 0;
1799 pint_t lsda = 0;
1800 pint_t personality = 0;
1801 uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
1802 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
1803 // regular page
1804 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
1805 secondLevelAddr);
1806 UnwindSectionRegularArray<A> pageIndex(
1807 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1808 // binary search looks for entry with e where index[e].offset <= pc <
1809 // index[e+1].offset
1810 if (log)
1811 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
1812 "regular page starting at secondLevelAddr=0x%llX\n",
1813 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
1814 low = 0;
1815 high = pageHeader.entryCount();
1816 while (low < high) {
1817 uint32_t mid = (low + high) / 2;
1818 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
1819 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
1820 // at end of table
1821 low = mid;
1822 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1823 break;
1824 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
1825 // next is too big, so we found it
1826 low = mid;
1827 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
1828 break;
1829 } else {
1830 low = mid + 1;
1831 }
1832 } else {
1833 high = mid;
1834 }
1835 }
1836 encoding = pageIndex.encoding(low);
1837 funcStart = pageIndex.functionOffset(low) + sects.dso_base;
1838 if (pc < funcStart) {
1839 if (log)
1840 fprintf(
1841 stderr,
1842 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1843 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1844 return false;
1845 }
1846 if (pc > funcEnd) {
1847 if (log)
1848 fprintf(
1849 stderr,
1850 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1851 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1852 return false;
1853 }
1854 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
1855 // compressed page
1856 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
1857 secondLevelAddr);
1858 UnwindSectionCompressedArray<A> pageIndex(
1859 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1860 const uint32_t targetFunctionPageOffset =
1861 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
1862 // binary search looks for entry with e where index[e].offset <= pc <
1863 // index[e+1].offset
1864 if (log)
1865 fprintf(stderr, "\tbinary search of compressed page starting at "
1866 "secondLevelAddr=0x%llX\n",
1867 (uint64_t) secondLevelAddr);
1868 low = 0;
1869 last = pageHeader.entryCount() - 1;
1870 high = pageHeader.entryCount();
1871 while (low < high) {
1872 uint32_t mid = (low + high) / 2;
1873 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
1874 if ((mid == last) ||
1875 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
1876 low = mid;
1877 break;
1878 } else {
1879 low = mid + 1;
1880 }
1881 } else {
1882 high = mid;
1883 }
1884 }
1885 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
1886 + sects.dso_base;
1887 if (low < last)
1888 funcEnd =
1889 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
1890 + sects.dso_base;
1891 else
1892 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1893 if (pc < funcStart) {
1894 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1895 "not in second level compressed unwind table. "
1896 "funcStart=0x%llX",
1897 (uint64_t) pc, (uint64_t) funcStart);
1898 return false;
1899 }
1900 if (pc > funcEnd) {
1901 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1902 "not in second level compressed unwind table. "
1903 "funcEnd=0x%llX",
1904 (uint64_t) pc, (uint64_t) funcEnd);
1905 return false;
1906 }
1907 uint16_t encodingIndex = pageIndex.encodingIndex(low);
1908 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
1909 // encoding is in common table in section header
1910 encoding = _addressSpace.get32(
1911 sects.compact_unwind_section +
1912 sectionHeader.commonEncodingsArraySectionOffset() +
1913 encodingIndex * sizeof(uint32_t));
1914 } else {
1915 // encoding is in page specific table
1916 uint16_t pageEncodingIndex =
1917 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
1918 encoding = _addressSpace.get32(secondLevelAddr +
1919 pageHeader.encodingsPageOffset() +
1920 pageEncodingIndex * sizeof(uint32_t));
1921 }
1922 } else {
1923 _LIBUNWIND_DEBUG_LOG(
1924 "malformed __unwind_info at 0x%0llX bad second level page",
1925 (uint64_t)sects.compact_unwind_section);
1926 return false;
1927 }
1928
1929 // look up LSDA, if encoding says function has one
1930 if (encoding & UNWIND_HAS_LSDA) {
1931 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
1932 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
1933 low = 0;
1934 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
1935 sizeof(unwind_info_section_header_lsda_index_entry);
1936 // binary search looks for entry with exact match for functionOffset
1937 if (log)
1938 fprintf(stderr,
1939 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
1940 funcStartOffset);
1941 while (low < high) {
1942 uint32_t mid = (low + high) / 2;
1943 if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
1944 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
1945 break;
1946 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
1947 low = mid + 1;
1948 } else {
1949 high = mid;
1950 }
1951 }
1952 if (lsda == 0) {
1953 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
1954 "pc=0x%0llX, but lsda table has no entry",
1955 encoding, (uint64_t) pc);
1956 return false;
1957 }
1958 }
1959
1960 // extract personality routine, if encoding says function has one
1961 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
1962 (__builtin_ctz(UNWIND_PERSONALITY_MASK));
1963 if (personalityIndex != 0) {
1964 --personalityIndex; // change 1-based to zero-based index
1965 if (personalityIndex >= sectionHeader.personalityArrayCount()) {
1966 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
1967 "but personality table has only %d entries",
1968 encoding, personalityIndex,
1969 sectionHeader.personalityArrayCount());
1970 return false;
1971 }
1972 int32_t personalityDelta = (int32_t)_addressSpace.get32(
1973 sects.compact_unwind_section +
1974 sectionHeader.personalityArraySectionOffset() +
1975 personalityIndex * sizeof(uint32_t));
1976 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
1977 personality = _addressSpace.getP(personalityPointer);
1978 if (log)
1979 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1980 "personalityDelta=0x%08X, personality=0x%08llX\n",
1981 (uint64_t) pc, personalityDelta, (uint64_t) personality);
1982 }
1983
1984 if (log)
1985 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1986 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
1987 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
1988 _info.start_ip = funcStart;
1989 _info.end_ip = funcEnd;
1990 _info.lsda = lsda;
1991 _info.handler = personality;
1992 _info.gp = 0;
1993 _info.flags = 0;
1994 _info.format = encoding;
1995 _info.unwind_info = 0;
1996 _info.unwind_info_size = 0;
1997 _info.extra = sects.dso_base;
1998 return true;
1999 }
2000 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2001
2002
2003 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2004 template <typename A, typename R>
getInfoFromSEH(pint_t pc)2005 bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
2006 pint_t base;
2007 RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
2008 if (!unwindEntry) {
2009 _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
2010 return false;
2011 }
2012 _info.gp = 0;
2013 _info.flags = 0;
2014 _info.format = 0;
2015 _info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
2016 _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
2017 _info.extra = base;
2018 _info.start_ip = base + unwindEntry->BeginAddress;
2019 #ifdef _LIBUNWIND_TARGET_X86_64
2020 _info.end_ip = base + unwindEntry->EndAddress;
2021 // Only fill in the handler and LSDA if they're stale.
2022 if (pc != getLastPC()) {
2023 UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
2024 if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
2025 // The personality is given in the UNWIND_INFO itself. The LSDA immediately
2026 // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
2027 // these structures.)
2028 // N.B. UNWIND_INFO structs are DWORD-aligned.
2029 uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
2030 const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
2031 _info.lsda = reinterpret_cast<unw_word_t>(handler+1);
2032 _dispContext.HandlerData = reinterpret_cast<void *>(_info.lsda);
2033 _dispContext.LanguageHandler =
2034 reinterpret_cast<EXCEPTION_ROUTINE *>(base + *handler);
2035 if (*handler) {
2036 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2037 } else
2038 _info.handler = 0;
2039 } else {
2040 _info.lsda = 0;
2041 _info.handler = 0;
2042 }
2043 }
2044 #elif defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_ARM)
2045
2046 #if defined(_LIBUNWIND_TARGET_AARCH64)
2047 #define FUNC_LENGTH_UNIT 4
2048 #define XDATA_TYPE IMAGE_ARM64_RUNTIME_FUNCTION_ENTRY_XDATA
2049 #else
2050 #define FUNC_LENGTH_UNIT 2
2051 #define XDATA_TYPE UNWIND_INFO_ARM
2052 #endif
2053 if (unwindEntry->Flag != 0) { // Packed unwind info
2054 _info.end_ip =
2055 _info.start_ip + unwindEntry->FunctionLength * FUNC_LENGTH_UNIT;
2056 // Only fill in the handler and LSDA if they're stale.
2057 if (pc != getLastPC()) {
2058 // Packed unwind info doesn't have an exception handler.
2059 _info.lsda = 0;
2060 _info.handler = 0;
2061 }
2062 } else {
2063 XDATA_TYPE *xdata =
2064 reinterpret_cast<XDATA_TYPE *>(base + unwindEntry->UnwindData);
2065 _info.end_ip = _info.start_ip + xdata->FunctionLength * FUNC_LENGTH_UNIT;
2066 // Only fill in the handler and LSDA if they're stale.
2067 if (pc != getLastPC()) {
2068 if (xdata->ExceptionDataPresent) {
2069 uint32_t offset = 1; // The main xdata
2070 uint32_t codeWords = xdata->CodeWords;
2071 uint32_t epilogScopes = xdata->EpilogCount;
2072 if (xdata->EpilogCount == 0 && xdata->CodeWords == 0) {
2073 // The extension word has got the same layout for both ARM and ARM64
2074 uint32_t extensionWord = reinterpret_cast<uint32_t *>(xdata)[1];
2075 codeWords = (extensionWord >> 16) & 0xff;
2076 epilogScopes = extensionWord & 0xffff;
2077 offset++;
2078 }
2079 if (!xdata->EpilogInHeader)
2080 offset += epilogScopes;
2081 offset += codeWords;
2082 uint32_t *exceptionHandlerInfo =
2083 reinterpret_cast<uint32_t *>(xdata) + offset;
2084 _dispContext.HandlerData = &exceptionHandlerInfo[1];
2085 _dispContext.LanguageHandler = reinterpret_cast<EXCEPTION_ROUTINE *>(
2086 base + exceptionHandlerInfo[0]);
2087 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
2088 if (exceptionHandlerInfo[0])
2089 _info.handler =
2090 reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2091 else
2092 _info.handler = 0;
2093 } else {
2094 _info.lsda = 0;
2095 _info.handler = 0;
2096 }
2097 }
2098 }
2099 #endif
2100 setLastPC(pc);
2101 return true;
2102 }
2103 #endif
2104
2105 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2106 // Masks for traceback table field xtbtable.
2107 enum xTBTableMask : uint8_t {
2108 reservedBit = 0x02, // The traceback table was incorrectly generated if set
2109 // (see comments in function getInfoFromTBTable().
2110 ehInfoBit = 0x08 // Exception handling info is present if set
2111 };
2112
2113 enum frameType : unw_word_t {
2114 frameWithXLEHStateTable = 0,
2115 frameWithEHInfo = 1
2116 };
2117
2118 extern "C" {
2119 typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
2120 uint64_t,
2121 _Unwind_Exception *,
2122 struct _Unwind_Context *);
2123 }
2124
2125 static __xlcxx_personality_v0_t *xlcPersonalityV0;
2126 static RWMutex xlcPersonalityV0InitLock;
2127
2128 template <typename A, typename R>
getInfoFromTBTable(pint_t pc,R & registers)2129 bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R ®isters) {
2130 uint32_t *p = reinterpret_cast<uint32_t *>(pc);
2131
2132 // Keep looking forward until a word of 0 is found. The traceback
2133 // table starts at the following word.
2134 while (*p)
2135 ++p;
2136 tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
2137
2138 if (_LIBUNWIND_TRACING_UNWINDING) {
2139 char functionBuf[512];
2140 const char *functionName = functionBuf;
2141 unw_word_t offset;
2142 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2143 functionName = ".anonymous.";
2144 }
2145 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2146 __func__, functionName,
2147 reinterpret_cast<void *>(TBTable));
2148 }
2149
2150 // If the traceback table does not contain necessary info, bypass this frame.
2151 if (!TBTable->tb.has_tboff)
2152 return false;
2153
2154 // Structure tbtable_ext contains important data we are looking for.
2155 p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2156
2157 // Skip field parminfo if it exists.
2158 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2159 ++p;
2160
2161 // p now points to tb_offset, the offset from start of function to TB table.
2162 unw_word_t start_ip =
2163 reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
2164 unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
2165 ++p;
2166
2167 _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
2168 reinterpret_cast<void *>(start_ip),
2169 reinterpret_cast<void *>(end_ip));
2170
2171 // Skip field hand_mask if it exists.
2172 if (TBTable->tb.int_hndl)
2173 ++p;
2174
2175 unw_word_t lsda = 0;
2176 unw_word_t handler = 0;
2177 unw_word_t flags = frameType::frameWithXLEHStateTable;
2178
2179 if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
2180 // State table info is available. The ctl_info field indicates the
2181 // number of CTL anchors. There should be only one entry for the C++
2182 // state table.
2183 assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
2184 ++p;
2185 // p points to the offset of the state table into the stack.
2186 pint_t stateTableOffset = *p++;
2187
2188 int framePointerReg;
2189
2190 // Skip fields name_len and name if exist.
2191 if (TBTable->tb.name_present) {
2192 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
2193 p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
2194 sizeof(uint16_t));
2195 }
2196
2197 if (TBTable->tb.uses_alloca)
2198 framePointerReg = *(reinterpret_cast<char *>(p));
2199 else
2200 framePointerReg = 1; // default frame pointer == SP
2201
2202 _LIBUNWIND_TRACE_UNWINDING(
2203 "framePointerReg=%d, framePointer=%p, "
2204 "stateTableOffset=%#lx\n",
2205 framePointerReg,
2206 reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
2207 stateTableOffset);
2208 lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
2209
2210 // Since the traceback table generated by the legacy XLC++ does not
2211 // provide the location of the personality for the state table,
2212 // function __xlcxx_personality_v0(), which is the personality for the state
2213 // table and is exported from libc++abi, is directly assigned as the
2214 // handler here. When a legacy XLC++ frame is encountered, the symbol
2215 // is resolved dynamically using dlopen() to avoid a hard dependency of
2216 // libunwind on libc++abi in cases such as non-C++ applications.
2217
2218 // Resolve the function pointer to the state table personality if it has
2219 // not already been done.
2220 if (xlcPersonalityV0 == NULL) {
2221 xlcPersonalityV0InitLock.lock();
2222 if (xlcPersonalityV0 == NULL) {
2223 // Resolve __xlcxx_personality_v0 using dlopen().
2224 const char *libcxxabi = "libc++abi.a(libc++abi.so.1)";
2225 void *libHandle;
2226 // The AIX dlopen() sets errno to 0 when it is successful, which
2227 // clobbers the value of errno from the user code. This is an AIX
2228 // bug because according to POSIX it should not set errno to 0. To
2229 // workaround before AIX fixes the bug, errno is saved and restored.
2230 int saveErrno = errno;
2231 libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
2232 if (libHandle == NULL) {
2233 _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n", errno);
2234 assert(0 && "dlopen() failed");
2235 }
2236 xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
2237 dlsym(libHandle, "__xlcxx_personality_v0"));
2238 if (xlcPersonalityV0 == NULL) {
2239 _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
2240 dlclose(libHandle);
2241 assert(0 && "dlsym() failed");
2242 }
2243 errno = saveErrno;
2244 }
2245 xlcPersonalityV0InitLock.unlock();
2246 }
2247 handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
2248 _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
2249 reinterpret_cast<void *>(lsda),
2250 reinterpret_cast<void *>(handler));
2251 } else if (TBTable->tb.longtbtable) {
2252 // This frame has the traceback table extension. Possible cases are
2253 // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
2254 // is not EH aware; or, 3) a frame of other languages. We need to figure out
2255 // if the traceback table extension contains the 'eh_info' structure.
2256 //
2257 // We also need to deal with the complexity arising from some XL compiler
2258 // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
2259 // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
2260 // versa. For frames of code generated by those compilers, the 'longtbtable'
2261 // bit may be set but there isn't really a traceback table extension.
2262 //
2263 // In </usr/include/sys/debug.h>, there is the following definition of
2264 // 'struct tbtable_ext'. It is not really a structure but a dummy to
2265 // collect the description of optional parts of the traceback table.
2266 //
2267 // struct tbtable_ext {
2268 // ...
2269 // char alloca_reg; /* Register for alloca automatic storage */
2270 // struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
2271 // unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
2272 // };
2273 //
2274 // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
2275 // following 'alloca_reg' can be treated either as 'struct vec_ext' or
2276 // 'unsigned char xtbtable'. 'xtbtable' bits are defined in
2277 // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
2278 // unused and should not be set. 'struct vec_ext' is defined in
2279 // </usr/include/sys/debug.h> as follows:
2280 //
2281 // struct vec_ext {
2282 // unsigned vr_saved:6; /* Number of non-volatile vector regs saved
2283 // */
2284 // /* first register saved is assumed to be */
2285 // /* 32 - vr_saved */
2286 // unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */
2287 // unsigned has_varargs:1;
2288 // ...
2289 // };
2290 //
2291 // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
2292 // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
2293 // we checks if the 7th bit is set or not because 'xtbtable' should
2294 // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
2295 // in the future to make sure the mitigation works. This mitigation
2296 // is not 100% bullet proof because 'struct vec_ext' may not always have
2297 // 'saves_vrsave' bit set.
2298 //
2299 // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
2300 // checking the 7th bit.
2301
2302 // p points to field name len.
2303 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2304
2305 // Skip fields name_len and name if they exist.
2306 if (TBTable->tb.name_present) {
2307 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2308 charPtr = charPtr + name_len + sizeof(uint16_t);
2309 }
2310
2311 // Skip field alloc_reg if it exists.
2312 if (TBTable->tb.uses_alloca)
2313 ++charPtr;
2314
2315 // Check traceback table bit has_vec. Skip struct vec_ext if it exists.
2316 if (TBTable->tb.has_vec)
2317 // Note struct vec_ext does exist at this point because whether the
2318 // ordering of longtbtable and has_vec bits is correct or not, both
2319 // are set.
2320 charPtr += sizeof(struct vec_ext);
2321
2322 // charPtr points to field 'xtbtable'. Check if the EH info is available.
2323 // Also check if the reserved bit of the extended traceback table field
2324 // 'xtbtable' is set. If it is, the traceback table was incorrectly
2325 // generated by an XL compiler that uses the wrong ordering of 'longtbtable'
2326 // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
2327 // frame.
2328 if ((*charPtr & xTBTableMask::ehInfoBit) &&
2329 !(*charPtr & xTBTableMask::reservedBit)) {
2330 // Mark this frame has the new EH info.
2331 flags = frameType::frameWithEHInfo;
2332
2333 // eh_info is available.
2334 charPtr++;
2335 // The pointer is 4-byte aligned.
2336 if (reinterpret_cast<uintptr_t>(charPtr) % 4)
2337 charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
2338 uintptr_t *ehInfo =
2339 reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
2340 registers.getRegister(2) +
2341 *(reinterpret_cast<uintptr_t *>(charPtr)))));
2342
2343 // ehInfo points to structure en_info. The first member is version.
2344 // Only version 0 is currently supported.
2345 assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
2346 "libunwind: ehInfo version other than 0 is not supported");
2347
2348 // Increment ehInfo to point to member lsda.
2349 ++ehInfo;
2350 lsda = *ehInfo++;
2351
2352 // enInfo now points to member personality.
2353 handler = *ehInfo;
2354
2355 _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
2356 lsda, handler);
2357 }
2358 }
2359
2360 _info.start_ip = start_ip;
2361 _info.end_ip = end_ip;
2362 _info.lsda = lsda;
2363 _info.handler = handler;
2364 _info.gp = 0;
2365 _info.flags = flags;
2366 _info.format = 0;
2367 _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
2368 _info.unwind_info_size = 0;
2369 _info.extra = registers.getRegister(2);
2370
2371 return true;
2372 }
2373
2374 // Step back up the stack following the frame back link.
2375 template <typename A, typename R>
stepWithTBTable(pint_t pc,tbtable * TBTable,R & registers,bool & isSignalFrame)2376 int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
2377 R ®isters, bool &isSignalFrame) {
2378 if (_LIBUNWIND_TRACING_UNWINDING) {
2379 char functionBuf[512];
2380 const char *functionName = functionBuf;
2381 unw_word_t offset;
2382 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2383 functionName = ".anonymous.";
2384 }
2385 _LIBUNWIND_TRACE_UNWINDING(
2386 "%s: Look up traceback table of func=%s at %p, pc=%p, "
2387 "SP=%p, saves_lr=%d, stores_bc=%d",
2388 __func__, functionName, reinterpret_cast<void *>(TBTable),
2389 reinterpret_cast<void *>(pc),
2390 reinterpret_cast<void *>(registers.getSP()), TBTable->tb.saves_lr,
2391 TBTable->tb.stores_bc);
2392 }
2393
2394 #if defined(__powerpc64__)
2395 // Instruction to reload TOC register "ld r2,40(r1)"
2396 const uint32_t loadTOCRegInst = 0xe8410028;
2397 const int32_t unwPPCF0Index = UNW_PPC64_F0;
2398 const int32_t unwPPCV0Index = UNW_PPC64_V0;
2399 #else
2400 // Instruction to reload TOC register "lwz r2,20(r1)"
2401 const uint32_t loadTOCRegInst = 0x80410014;
2402 const int32_t unwPPCF0Index = UNW_PPC_F0;
2403 const int32_t unwPPCV0Index = UNW_PPC_V0;
2404 #endif
2405
2406 // lastStack points to the stack frame of the next routine up.
2407 pint_t curStack = static_cast<pint_t>(registers.getSP());
2408 pint_t lastStack = *reinterpret_cast<pint_t *>(curStack);
2409
2410 if (lastStack == 0)
2411 return UNW_STEP_END;
2412
2413 R newRegisters = registers;
2414
2415 // If backchain is not stored, use the current stack frame.
2416 if (!TBTable->tb.stores_bc)
2417 lastStack = curStack;
2418
2419 // Return address is the address after call site instruction.
2420 pint_t returnAddress;
2421
2422 if (isSignalFrame) {
2423 _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
2424 reinterpret_cast<void *>(lastStack));
2425
2426 sigcontext *sigContext = reinterpret_cast<sigcontext *>(
2427 reinterpret_cast<char *>(lastStack) + STKMINALIGN);
2428 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2429
2430 bool useSTKMIN = false;
2431 if (returnAddress < 0x10000000) {
2432 // Try again using STKMIN.
2433 sigContext = reinterpret_cast<sigcontext *>(
2434 reinterpret_cast<char *>(lastStack) + STKMIN);
2435 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2436 if (returnAddress < 0x10000000) {
2437 _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p from sigcontext=%p",
2438 reinterpret_cast<void *>(returnAddress),
2439 reinterpret_cast<void *>(sigContext));
2440 return UNW_EBADFRAME;
2441 }
2442 useSTKMIN = true;
2443 }
2444 _LIBUNWIND_TRACE_UNWINDING("Returning from a signal handler %s: "
2445 "sigContext=%p, returnAddress=%p. "
2446 "Seems to be a valid address",
2447 useSTKMIN ? "STKMIN" : "STKMINALIGN",
2448 reinterpret_cast<void *>(sigContext),
2449 reinterpret_cast<void *>(returnAddress));
2450
2451 // Restore the condition register from sigcontext.
2452 newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
2453
2454 // Save the LR in sigcontext for stepping up when the function that
2455 // raised the signal is a leaf function. This LR has the return address
2456 // to the caller of the leaf function.
2457 newRegisters.setLR(sigContext->sc_jmpbuf.jmp_context.lr);
2458 _LIBUNWIND_TRACE_UNWINDING(
2459 "Save LR=%p from sigcontext",
2460 reinterpret_cast<void *>(sigContext->sc_jmpbuf.jmp_context.lr));
2461
2462 // Restore GPRs from sigcontext.
2463 for (int i = 0; i < 32; ++i)
2464 newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
2465
2466 // Restore FPRs from sigcontext.
2467 for (int i = 0; i < 32; ++i)
2468 newRegisters.setFloatRegister(i + unwPPCF0Index,
2469 sigContext->sc_jmpbuf.jmp_context.fpr[i]);
2470
2471 // Restore vector registers if there is an associated extended context
2472 // structure.
2473 if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
2474 ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
2475 if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
2476 for (int i = 0; i < 32; ++i)
2477 newRegisters.setVectorRegister(
2478 i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
2479 &(uContext->__extctx->__vmx.__vr[i]))));
2480 }
2481 }
2482 } else {
2483 // Step up a normal frame.
2484
2485 if (!TBTable->tb.saves_lr && registers.getLR()) {
2486 // This case should only occur if we were called from a signal handler
2487 // and the signal occurred in a function that doesn't save the LR.
2488 returnAddress = static_cast<pint_t>(registers.getLR());
2489 _LIBUNWIND_TRACE_UNWINDING("Use saved LR=%p",
2490 reinterpret_cast<void *>(returnAddress));
2491 } else {
2492 // Otherwise, use the LR value in the stack link area.
2493 returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
2494 }
2495
2496 // Reset LR in the current context.
2497 newRegisters.setLR(static_cast<uintptr_t>(NULL));
2498
2499 _LIBUNWIND_TRACE_UNWINDING(
2500 "Extract info from lastStack=%p, returnAddress=%p",
2501 reinterpret_cast<void *>(lastStack),
2502 reinterpret_cast<void *>(returnAddress));
2503 _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d",
2504 TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
2505 TBTable->tb.saves_cr);
2506
2507 // Restore FP registers.
2508 char *ptrToRegs = reinterpret_cast<char *>(lastStack);
2509 double *FPRegs = reinterpret_cast<double *>(
2510 ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
2511 for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
2512 newRegisters.setFloatRegister(
2513 32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
2514
2515 // Restore GP registers.
2516 ptrToRegs = reinterpret_cast<char *>(FPRegs);
2517 uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
2518 ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
2519 for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
2520 newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
2521
2522 // Restore Vector registers.
2523 ptrToRegs = reinterpret_cast<char *>(GPRegs);
2524
2525 // Restore vector registers only if this is a Clang frame. Also
2526 // check if traceback table bit has_vec is set. If it is, structure
2527 // vec_ext is available.
2528 if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
2529
2530 // Get to the vec_ext structure to check if vector registers are saved.
2531 uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2532
2533 // Skip field parminfo if exists.
2534 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2535 ++p;
2536
2537 // Skip field tb_offset if exists.
2538 if (TBTable->tb.has_tboff)
2539 ++p;
2540
2541 // Skip field hand_mask if exists.
2542 if (TBTable->tb.int_hndl)
2543 ++p;
2544
2545 // Skip fields ctl_info and ctl_info_disp if exist.
2546 if (TBTable->tb.has_ctl) {
2547 // Skip field ctl_info.
2548 ++p;
2549 // Skip field ctl_info_disp.
2550 ++p;
2551 }
2552
2553 // Skip fields name_len and name if exist.
2554 // p is supposed to point to field name_len now.
2555 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2556 if (TBTable->tb.name_present) {
2557 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2558 charPtr = charPtr + name_len + sizeof(uint16_t);
2559 }
2560
2561 // Skip field alloc_reg if it exists.
2562 if (TBTable->tb.uses_alloca)
2563 ++charPtr;
2564
2565 struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
2566
2567 _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d", vec_ext->vr_saved);
2568
2569 // Restore vector register(s) if saved on the stack.
2570 if (vec_ext->vr_saved) {
2571 // Saved vector registers are 16-byte aligned.
2572 if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
2573 ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
2574 v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
2575 sizeof(v128));
2576 for (int i = 0; i < vec_ext->vr_saved; ++i) {
2577 newRegisters.setVectorRegister(
2578 32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
2579 }
2580 }
2581 }
2582 if (TBTable->tb.saves_cr) {
2583 // Get the saved condition register. The condition register is only
2584 // a single word.
2585 newRegisters.setCR(
2586 *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
2587 }
2588
2589 // Restore the SP.
2590 newRegisters.setSP(lastStack);
2591
2592 // The first instruction after return.
2593 uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
2594
2595 // Do we need to set the TOC register?
2596 _LIBUNWIND_TRACE_UNWINDING(
2597 "Current gpr2=%p",
2598 reinterpret_cast<void *>(newRegisters.getRegister(2)));
2599 if (firstInstruction == loadTOCRegInst) {
2600 _LIBUNWIND_TRACE_UNWINDING(
2601 "Set gpr2=%p from frame",
2602 reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
2603 newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
2604 }
2605 }
2606 _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
2607 reinterpret_cast<void *>(lastStack),
2608 reinterpret_cast<void *>(returnAddress),
2609 reinterpret_cast<void *>(pc));
2610
2611 // The return address is the address after call site instruction, so
2612 // setting IP to that simulates a return.
2613 newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
2614
2615 // Simulate the step by replacing the register set with the new ones.
2616 registers = newRegisters;
2617
2618 // Check if the next frame is a signal frame.
2619 pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2620
2621 // Return address is the address after call site instruction.
2622 pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
2623
2624 if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
2625 _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
2626 "nextStack=%p, next return address=%p\n",
2627 reinterpret_cast<void *>(nextStack),
2628 reinterpret_cast<void *>(nextReturnAddress));
2629 isSignalFrame = true;
2630 } else {
2631 isSignalFrame = false;
2632 }
2633 return UNW_STEP_SUCCESS;
2634 }
2635 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2636
2637 template <typename A, typename R>
setInfoBasedOnIPRegister(bool isReturnAddress)2638 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
2639 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
2640 defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
2641 _isSigReturn = false;
2642 #endif
2643
2644 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2645 #if defined(_LIBUNWIND_ARM_EHABI)
2646 // Remove the thumb bit so the IP represents the actual instruction address.
2647 // This matches the behaviour of _Unwind_GetIP on arm.
2648 pc &= (pint_t)~0x1;
2649 #endif
2650
2651 // Exit early if at the top of the stack.
2652 if (pc == 0) {
2653 _unwindInfoMissing = true;
2654 return;
2655 }
2656
2657 // If the last line of a function is a "throw" the compiler sometimes
2658 // emits no instructions after the call to __cxa_throw. This means
2659 // the return address is actually the start of the next function.
2660 // To disambiguate this, back up the pc when we know it is a return
2661 // address.
2662 if (isReturnAddress)
2663 #if defined(_AIX)
2664 // PC needs to be a 4-byte aligned address to be able to look for a
2665 // word of 0 that indicates the start of the traceback table at the end
2666 // of a function on AIX.
2667 pc -= 4;
2668 #else
2669 --pc;
2670 #endif
2671
2672 #if !(defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)) && \
2673 !defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2674 // In case of this is frame of signal handler, the IP saved in the signal
2675 // handler points to first non-executed instruction, while FDE/CIE expects IP
2676 // to be after the first non-executed instruction.
2677 if (_isSignalFrame)
2678 ++pc;
2679 #endif
2680
2681 // Ask address space object to find unwind sections for this pc.
2682 UnwindInfoSections sects;
2683 if (_addressSpace.findUnwindSections(pc, sects)) {
2684 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2685 // If there is a compact unwind encoding table, look there first.
2686 if (sects.compact_unwind_section != 0) {
2687 if (this->getInfoFromCompactEncodingSection(pc, sects)) {
2688 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2689 // Found info in table, done unless encoding says to use dwarf.
2690 uint32_t dwarfOffset;
2691 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
2692 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
2693 // found info in dwarf, done
2694 return;
2695 }
2696 }
2697 #endif
2698 // If unwind table has entry, but entry says there is no unwind info,
2699 // record that we have no unwind info.
2700 if (_info.format == 0)
2701 _unwindInfoMissing = true;
2702 return;
2703 }
2704 }
2705 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2706
2707 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2708 // If there is SEH unwind info, look there next.
2709 if (this->getInfoFromSEH(pc))
2710 return;
2711 #endif
2712
2713 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2714 // If there is unwind info in the traceback table, look there next.
2715 if (this->getInfoFromTBTable(pc, _registers))
2716 return;
2717 #endif
2718
2719 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2720 // If there is dwarf unwind info, look there next.
2721 if (sects.dwarf_section != 0) {
2722 if (this->getInfoFromDwarfSection(pc, sects)) {
2723 // found info in dwarf, done
2724 return;
2725 }
2726 }
2727 #endif
2728
2729 #if defined(_LIBUNWIND_ARM_EHABI)
2730 // If there is ARM EHABI unwind info, look there next.
2731 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
2732 return;
2733 #endif
2734 }
2735
2736 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2737 // There is no static unwind info for this pc. Look to see if an FDE was
2738 // dynamically registered for it.
2739 pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
2740 pc);
2741 if (cachedFDE != 0) {
2742 typename CFI_Parser<A>::FDE_Info fdeInfo;
2743 typename CFI_Parser<A>::CIE_Info cieInfo;
2744 if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
2745 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2746 return;
2747 }
2748
2749 // Lastly, ask AddressSpace object about platform specific ways to locate
2750 // other FDEs.
2751 pint_t fde;
2752 if (_addressSpace.findOtherFDE(pc, fde)) {
2753 typename CFI_Parser<A>::FDE_Info fdeInfo;
2754 typename CFI_Parser<A>::CIE_Info cieInfo;
2755 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
2756 // Double check this FDE is for a function that includes the pc.
2757 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
2758 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2759 return;
2760 }
2761 }
2762 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2763
2764 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
2765 defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
2766 if (setInfoForSigReturn())
2767 return;
2768 #endif
2769
2770 // no unwind info, flag that we can't reliably unwind
2771 _unwindInfoMissing = true;
2772 }
2773
2774 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2775 defined(_LIBUNWIND_TARGET_AARCH64)
2776 template <typename A, typename R>
setInfoForSigReturn(Registers_arm64 &)2777 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
2778 // Look for the sigreturn trampoline. The trampoline's body is two
2779 // specific instructions (see below). Typically the trampoline comes from the
2780 // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
2781 // own restorer function, though, or user-mode QEMU might write a trampoline
2782 // onto the stack.
2783 //
2784 // This special code path is a fallback that is only used if the trampoline
2785 // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
2786 // constant for the PC needs to be defined before DWARF can handle a signal
2787 // trampoline. This code may segfault if the target PC is unreadable, e.g.:
2788 // - The PC points at a function compiled without unwind info, and which is
2789 // part of an execute-only mapping (e.g. using -Wl,--execute-only).
2790 // - The PC is invalid and happens to point to unreadable or unmapped memory.
2791 //
2792 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
2793 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2794 // The PC might contain an invalid address if the unwind info is bad, so
2795 // directly accessing it could cause a SIGSEGV.
2796 if (!isReadableAddr(pc))
2797 return false;
2798 auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2799 // Look for instructions: mov x8, #0x8b; svc #0x0
2800 if (instructions[0] != 0xd2801168 || instructions[1] != 0xd4000001)
2801 return false;
2802
2803 _info = {};
2804 _info.start_ip = pc;
2805 _info.end_ip = pc + 4;
2806 _isSigReturn = true;
2807 return true;
2808 }
2809
2810 template <typename A, typename R>
stepThroughSigReturn(Registers_arm64 &)2811 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
2812 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2813 // - 128-byte siginfo struct
2814 // - ucontext struct:
2815 // - 8-byte long (uc_flags)
2816 // - 8-byte pointer (uc_link)
2817 // - 24-byte stack_t
2818 // - 128-byte signal set
2819 // - 8 bytes of padding because sigcontext has 16-byte alignment
2820 // - sigcontext/mcontext_t
2821 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
2822 const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
2823
2824 // Offsets from sigcontext to each register.
2825 const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
2826 const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
2827 const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
2828
2829 pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2830
2831 for (int i = 0; i <= 30; ++i) {
2832 uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
2833 static_cast<pint_t>(i * 8));
2834 _registers.setRegister(UNW_AARCH64_X0 + i, value);
2835 }
2836 _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
2837 _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
2838 _isSignalFrame = true;
2839 return UNW_STEP_SUCCESS;
2840 }
2841 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2842 // defined(_LIBUNWIND_TARGET_AARCH64)
2843
2844 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2845 defined(_LIBUNWIND_TARGET_LOONGARCH)
2846 template <typename A, typename R>
setInfoForSigReturn(Registers_loongarch &)2847 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_loongarch &) {
2848 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2849 // The PC might contain an invalid address if the unwind info is bad, so
2850 // directly accessing it could cause a SIGSEGV.
2851 if (!isReadableAddr(pc))
2852 return false;
2853 const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2854 // Look for the two instructions used in the sigreturn trampoline
2855 // __vdso_rt_sigreturn:
2856 //
2857 // 0x03822c0b li a7,0x8b
2858 // 0x002b0000 syscall 0
2859 if (instructions[0] != 0x03822c0b || instructions[1] != 0x002b0000)
2860 return false;
2861
2862 _info = {};
2863 _info.start_ip = pc;
2864 _info.end_ip = pc + 4;
2865 _isSigReturn = true;
2866 return true;
2867 }
2868
2869 template <typename A, typename R>
stepThroughSigReturn(Registers_loongarch &)2870 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_loongarch &) {
2871 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2872 // - 128-byte siginfo struct
2873 // - ucontext_t struct:
2874 // - 8-byte long (__uc_flags)
2875 // - 8-byte pointer (*uc_link)
2876 // - 24-byte uc_stack
2877 // - 8-byte uc_sigmask
2878 // - 120-byte of padding to allow sigset_t to be expanded in the future
2879 // - 8 bytes of padding because sigcontext has 16-byte alignment
2880 // - struct sigcontext uc_mcontext
2881 // [1]
2882 // https://github.com/torvalds/linux/blob/master/arch/loongarch/kernel/signal.c
2883 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2884
2885 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2886 _registers.setIP(_addressSpace.get64(sigctx));
2887 for (int i = UNW_LOONGARCH_R1; i <= UNW_LOONGARCH_R31; ++i) {
2888 // skip R0
2889 uint64_t value =
2890 _addressSpace.get64(sigctx + static_cast<pint_t>((i + 1) * 8));
2891 _registers.setRegister(i, value);
2892 }
2893 _isSignalFrame = true;
2894 return UNW_STEP_SUCCESS;
2895 }
2896 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2897 // defined(_LIBUNWIND_TARGET_LOONGARCH)
2898
2899 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2900 defined(_LIBUNWIND_TARGET_RISCV)
2901 template <typename A, typename R>
setInfoForSigReturn(Registers_riscv &)2902 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_riscv &) {
2903 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2904 // The PC might contain an invalid address if the unwind info is bad, so
2905 // directly accessing it could cause a SIGSEGV.
2906 if (!isReadableAddr(pc))
2907 return false;
2908 const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2909 // Look for the two instructions used in the sigreturn trampoline
2910 // __vdso_rt_sigreturn:
2911 //
2912 // 0x08b00893 li a7,0x8b
2913 // 0x00000073 ecall
2914 if (instructions[0] != 0x08b00893 || instructions[1] != 0x00000073)
2915 return false;
2916
2917 _info = {};
2918 _info.start_ip = pc;
2919 _info.end_ip = pc + 4;
2920 _isSigReturn = true;
2921 return true;
2922 }
2923
2924 template <typename A, typename R>
stepThroughSigReturn(Registers_riscv &)2925 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_riscv &) {
2926 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2927 // - 128-byte siginfo struct
2928 // - ucontext_t struct:
2929 // - 8-byte long (__uc_flags)
2930 // - 8-byte pointer (*uc_link)
2931 // - 24-byte uc_stack
2932 // - 8-byte uc_sigmask
2933 // - 120-byte of padding to allow sigset_t to be expanded in the future
2934 // - 8 bytes of padding because sigcontext has 16-byte alignment
2935 // - struct sigcontext uc_mcontext
2936 // [1]
2937 // https://github.com/torvalds/linux/blob/master/arch/riscv/kernel/signal.c
2938 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2939
2940 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2941 _registers.setIP(_addressSpace.get64(sigctx));
2942 for (int i = UNW_RISCV_X1; i <= UNW_RISCV_X31; ++i) {
2943 uint64_t value = _addressSpace.get64(sigctx + static_cast<pint_t>(i * 8));
2944 _registers.setRegister(i, value);
2945 }
2946 _isSignalFrame = true;
2947 return UNW_STEP_SUCCESS;
2948 }
2949 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2950 // defined(_LIBUNWIND_TARGET_RISCV)
2951
2952 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2953 defined(_LIBUNWIND_TARGET_S390X)
2954 template <typename A, typename R>
setInfoForSigReturn(Registers_s390x &)2955 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
2956 // Look for the sigreturn trampoline. The trampoline's body is a
2957 // specific instruction (see below). Typically the trampoline comes from the
2958 // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its
2959 // own restorer function, though, or user-mode QEMU might write a trampoline
2960 // onto the stack.
2961 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2962 // The PC might contain an invalid address if the unwind info is bad, so
2963 // directly accessing it could cause a SIGSEGV.
2964 if (!isReadableAddr(pc))
2965 return false;
2966 const auto inst = *reinterpret_cast<const uint16_t *>(pc);
2967 if (inst == 0x0a77 || inst == 0x0aad) {
2968 _info = {};
2969 _info.start_ip = pc;
2970 _info.end_ip = pc + 2;
2971 _isSigReturn = true;
2972 return true;
2973 }
2974 return false;
2975 }
2976
2977 template <typename A, typename R>
stepThroughSigReturn(Registers_s390x &)2978 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
2979 // Determine current SP.
2980 const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP));
2981 // According to the s390x ABI, the CFA is at (incoming) SP + 160.
2982 const pint_t cfa = sp + 160;
2983
2984 // Determine current PC and instruction there (this must be either
2985 // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn").
2986 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2987 const uint16_t inst = _addressSpace.get16(pc);
2988
2989 // Find the addresses of the signo and sigcontext in the frame.
2990 pint_t pSigctx = 0;
2991 pint_t pSigno = 0;
2992
2993 // "svc __NR_sigreturn" uses a non-RT signal trampoline frame.
2994 if (inst == 0x0a77) {
2995 // Layout of a non-RT signal trampoline frame, starting at the CFA:
2996 // - 8-byte signal mask
2997 // - 8-byte pointer to sigcontext, followed by signo
2998 // - 4-byte signo
2999 pSigctx = _addressSpace.get64(cfa + 8);
3000 pSigno = pSigctx + 344;
3001 }
3002
3003 // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame.
3004 if (inst == 0x0aad) {
3005 // Layout of a RT signal trampoline frame, starting at the CFA:
3006 // - 8-byte retcode (+ alignment)
3007 // - 128-byte siginfo struct (starts with signo)
3008 // - ucontext struct:
3009 // - 8-byte long (uc_flags)
3010 // - 8-byte pointer (uc_link)
3011 // - 24-byte stack_t
3012 // - 8 bytes of padding because sigcontext has 16-byte alignment
3013 // - sigcontext/mcontext_t
3014 pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8;
3015 pSigno = cfa + 8;
3016 }
3017
3018 assert(pSigctx != 0);
3019 assert(pSigno != 0);
3020
3021 // Offsets from sigcontext to each register.
3022 const pint_t kOffsetPc = 8;
3023 const pint_t kOffsetGprs = 16;
3024 const pint_t kOffsetFprs = 216;
3025
3026 // Restore all registers.
3027 for (int i = 0; i < 16; ++i) {
3028 uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs +
3029 static_cast<pint_t>(i * 8));
3030 _registers.setRegister(UNW_S390X_R0 + i, value);
3031 }
3032 for (int i = 0; i < 16; ++i) {
3033 static const int fpr[16] = {
3034 UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3,
3035 UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7,
3036 UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11,
3037 UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15
3038 };
3039 double value = _addressSpace.getDouble(pSigctx + kOffsetFprs +
3040 static_cast<pint_t>(i * 8));
3041 _registers.setFloatRegister(fpr[i], value);
3042 }
3043 _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc));
3044
3045 // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
3046 // after the faulting instruction rather than before it.
3047 // Do not set _isSignalFrame in that case.
3048 uint32_t signo = _addressSpace.get32(pSigno);
3049 _isSignalFrame = (signo != 4 && signo != 5 && signo != 8);
3050
3051 return UNW_STEP_SUCCESS;
3052 }
3053 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
3054 // defined(_LIBUNWIND_TARGET_S390X)
3055
3056 #if defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3057 template <typename A, typename R>
setInfoForSigReturn()3058 bool UnwindCursor<A, R>::setInfoForSigReturn() {
3059 Dl_info dlinfo;
3060 const auto isSignalHandler = [&](pint_t addr) {
3061 if (!dladdr(reinterpret_cast<void *>(addr), &dlinfo))
3062 return false;
3063 if (strcmp(dlinfo.dli_fname, "commpage"))
3064 return false;
3065 if (dlinfo.dli_sname == NULL ||
3066 strcmp(dlinfo.dli_sname, "commpage_signal_handler"))
3067 return false;
3068 return true;
3069 };
3070
3071 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
3072 if (!isSignalHandler(pc))
3073 return false;
3074
3075 pint_t start = reinterpret_cast<pint_t>(dlinfo.dli_saddr);
3076
3077 static size_t signalHandlerSize = 0;
3078 if (signalHandlerSize == 0) {
3079 size_t boundLow = 0;
3080 size_t boundHigh = static_cast<size_t>(-1);
3081
3082 area_info areaInfo;
3083 if (get_area_info(area_for(dlinfo.dli_saddr), &areaInfo) == B_OK)
3084 boundHigh = areaInfo.size;
3085
3086 while (boundLow < boundHigh) {
3087 size_t boundMid = boundLow + ((boundHigh - boundLow) / 2);
3088 pint_t test = start + boundMid;
3089 if (test >= start && isSignalHandler(test))
3090 boundLow = boundMid + 1;
3091 else
3092 boundHigh = boundMid;
3093 }
3094
3095 signalHandlerSize = boundHigh;
3096 }
3097
3098 _info = {};
3099 _info.start_ip = start;
3100 _info.end_ip = start + signalHandlerSize;
3101 _isSigReturn = true;
3102
3103 return true;
3104 }
3105
3106 template <typename A, typename R>
stepThroughSigReturn()3107 int UnwindCursor<A, R>::stepThroughSigReturn() {
3108 _isSignalFrame = true;
3109
3110 #if defined(_LIBUNWIND_TARGET_X86_64)
3111 // Layout of the stack before function call:
3112 // - signal_frame_data
3113 // + siginfo_t (public struct, fairly stable)
3114 // + ucontext_t (public struct, fairly stable)
3115 // - mcontext_t -> Offset 0x70, this is what we want.
3116 // - frame->ip (8 bytes)
3117 // - frame->bp (8 bytes). Not written by the kernel,
3118 // but the signal handler has a "push %rbp" instruction.
3119 pint_t bp = this->getReg(UNW_X86_64_RBP);
3120 vregs *regs = (vregs *)(bp + 0x70);
3121
3122 _registers.setRegister(UNW_REG_IP, regs->rip);
3123 _registers.setRegister(UNW_REG_SP, regs->rsp);
3124 _registers.setRegister(UNW_X86_64_RAX, regs->rax);
3125 _registers.setRegister(UNW_X86_64_RDX, regs->rdx);
3126 _registers.setRegister(UNW_X86_64_RCX, regs->rcx);
3127 _registers.setRegister(UNW_X86_64_RBX, regs->rbx);
3128 _registers.setRegister(UNW_X86_64_RSI, regs->rsi);
3129 _registers.setRegister(UNW_X86_64_RDI, regs->rdi);
3130 _registers.setRegister(UNW_X86_64_RBP, regs->rbp);
3131 _registers.setRegister(UNW_X86_64_R8, regs->r8);
3132 _registers.setRegister(UNW_X86_64_R9, regs->r9);
3133 _registers.setRegister(UNW_X86_64_R10, regs->r10);
3134 _registers.setRegister(UNW_X86_64_R11, regs->r11);
3135 _registers.setRegister(UNW_X86_64_R12, regs->r12);
3136 _registers.setRegister(UNW_X86_64_R13, regs->r13);
3137 _registers.setRegister(UNW_X86_64_R14, regs->r14);
3138 _registers.setRegister(UNW_X86_64_R15, regs->r15);
3139 // TODO: XMM
3140 #endif // defined(_LIBUNWIND_TARGET_X86_64)
3141
3142 return UNW_STEP_SUCCESS;
3143 }
3144 #endif // defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3145
step(bool stage2)3146 template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
3147 (void)stage2;
3148 // Bottom of stack is defined is when unwind info cannot be found.
3149 if (_unwindInfoMissing)
3150 return UNW_STEP_END;
3151
3152 // Use unwinding info to modify register set as if function returned.
3153 int result;
3154 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
3155 defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3156 if (_isSigReturn) {
3157 result = this->stepThroughSigReturn();
3158 } else
3159 #endif
3160 {
3161 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
3162 result = this->stepWithCompactEncoding(stage2);
3163 #elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
3164 result = this->stepWithSEHData();
3165 #elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
3166 result = this->stepWithTBTableData();
3167 #elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
3168 result = this->stepWithDwarfFDE(stage2);
3169 #elif defined(_LIBUNWIND_ARM_EHABI)
3170 result = this->stepWithEHABI();
3171 #else
3172 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
3173 _LIBUNWIND_SUPPORT_SEH_UNWIND or \
3174 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
3175 _LIBUNWIND_ARM_EHABI
3176 #endif
3177 }
3178
3179 // update info based on new PC
3180 if (result == UNW_STEP_SUCCESS) {
3181 this->setInfoBasedOnIPRegister(true);
3182 if (_unwindInfoMissing)
3183 return UNW_STEP_END;
3184 }
3185
3186 return result;
3187 }
3188
3189 template <typename A, typename R>
getInfo(unw_proc_info_t * info)3190 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
3191 if (_unwindInfoMissing)
3192 memset(info, 0, sizeof(*info));
3193 else
3194 *info = _info;
3195 }
3196
3197 template <typename A, typename R>
getFunctionName(char * buf,size_t bufLen,unw_word_t * offset)3198 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
3199 unw_word_t *offset) {
3200 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
3201 buf, bufLen, offset);
3202 }
3203
3204 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
3205 template <typename A, typename R>
isReadableAddr(const pint_t addr) const3206 bool UnwindCursor<A, R>::isReadableAddr(const pint_t addr) const {
3207 // We use SYS_rt_sigprocmask, inspired by Abseil's AddressIsReadable.
3208
3209 const auto sigsetAddr = reinterpret_cast<sigset_t *>(addr);
3210 // We have to check that addr is nullptr because sigprocmask allows that
3211 // as an argument without failure.
3212 if (!sigsetAddr)
3213 return false;
3214 const auto saveErrno = errno;
3215 // We MUST use a raw syscall here, as wrappers may try to access
3216 // sigsetAddr which may cause a SIGSEGV. A raw syscall however is
3217 // safe. Additionally, we need to pass the kernel_sigset_size, which is
3218 // different from libc sizeof(sigset_t). For the majority of architectures,
3219 // it's 64 bits (_NSIG), and libc NSIG is _NSIG + 1.
3220 const auto kernelSigsetSize = NSIG / 8;
3221 [[maybe_unused]] const int Result = syscall(
3222 SYS_rt_sigprocmask, /*how=*/~0, sigsetAddr, nullptr, kernelSigsetSize);
3223 // Because our "how" is invalid, this syscall should always fail, and our
3224 // errno should always be EINVAL or an EFAULT. This relies on the Linux
3225 // kernel to check copy_from_user before checking if the "how" argument is
3226 // invalid.
3227 assert(Result == -1);
3228 assert(errno == EFAULT || errno == EINVAL);
3229 const auto readable = errno != EFAULT;
3230 errno = saveErrno;
3231 return readable;
3232 }
3233 #endif
3234
3235 #if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
__libunwind_shstk_get_registers(unw_cursor_t * cursor)3236 extern "C" void *__libunwind_shstk_get_registers(unw_cursor_t *cursor) {
3237 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
3238 return co->get_registers();
3239 }
3240 #endif
3241 } // namespace libunwind
3242
3243 #endif // __UNWINDCURSOR_HPP__
3244