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Run DCE after a LoopFlatten test to reduce spurious output [nfc]
[llvm-project.git] / libunwind / src / UnwindCursor.hpp
blob647a5a9c9d92d916ebfedf5c2437581f9bf758c1
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //
8 // C++ interface to lower levels of libunwind
9 //===----------------------------------------------------------------------===//
10
11 #ifndef __UNWINDCURSOR_HPP__
12 #define __UNWINDCURSOR_HPP__
13
14 #include "cet_unwind.h"
15 #include <stdint.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <unwind.h>
19
20 #ifdef _WIN32
21 #include <windows.h>
22 #include <ntverp.h>
23 #endif
24 #ifdef __APPLE__
25 #include <mach-o/dyld.h>
26 #endif
27 #ifdef _AIX
28 #include <dlfcn.h>
29 #include <sys/debug.h>
30 #include <sys/pseg.h>
31 #endif
32
33 #if defined(_LIBUNWIND_TARGET_LINUX) && \
34 (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_RISCV) || \
35 defined(_LIBUNWIND_TARGET_S390X))
36 #include <sys/syscall.h>
37 #include <sys/uio.h>
38 #include <unistd.h>
39 #define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
40 #endif
41
42 #include "AddressSpace.hpp"
43 #include "CompactUnwinder.hpp"
44 #include "config.h"
45 #include "DwarfInstructions.hpp"
46 #include "EHHeaderParser.hpp"
47 #include "libunwind.h"
48 #include "libunwind_ext.h"
49 #include "Registers.hpp"
50 #include "RWMutex.hpp"
51 #include "Unwind-EHABI.h"
52
53 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
54 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
55 // earlier) SDKs.
56 // MinGW-w64 has always provided this struct.
57 #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
58 !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
59 struct _DISPATCHER_CONTEXT {
60 ULONG64 ControlPc;
61 ULONG64 ImageBase;
62 PRUNTIME_FUNCTION FunctionEntry;
63 ULONG64 EstablisherFrame;
64 ULONG64 TargetIp;
65 PCONTEXT ContextRecord;
66 PEXCEPTION_ROUTINE LanguageHandler;
67 PVOID HandlerData;
68 PUNWIND_HISTORY_TABLE HistoryTable;
69 ULONG ScopeIndex;
70 ULONG Fill0;
71 };
72 #endif
73
74 struct UNWIND_INFO {
75 uint8_t Version : 3;
76 uint8_t Flags : 5;
77 uint8_t SizeOfProlog;
78 uint8_t CountOfCodes;
79 uint8_t FrameRegister : 4;
80 uint8_t FrameOffset : 4;
81 uint16_t UnwindCodes[2];
82 };
83
84 extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
85 int, _Unwind_Action, uint64_t, _Unwind_Exception *,
86 struct _Unwind_Context *);
87
88 #endif
89
90 namespace libunwind {
91
92 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
93 /// Cache of recently found FDEs.
94 template <typename A>
95 class _LIBUNWIND_HIDDEN DwarfFDECache {
96 typedef typename A::pint_t pint_t;
97 public:
98 static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
99 static pint_t findFDE(pint_t mh, pint_t pc);
100 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
101 static void removeAllIn(pint_t mh);
102 static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
103 unw_word_t ip_end,
104 unw_word_t fde, unw_word_t mh));
105
106 private:
107
108 struct entry {
109 pint_t mh;
110 pint_t ip_start;
111 pint_t ip_end;
112 pint_t fde;
113 };
114
115 // These fields are all static to avoid needing an initializer.
116 // There is only one instance of this class per process.
117 static RWMutex _lock;
118 #ifdef __APPLE__
119 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
120 static bool _registeredForDyldUnloads;
121 #endif
122 static entry *_buffer;
123 static entry *_bufferUsed;
124 static entry *_bufferEnd;
125 static entry _initialBuffer[64];
126 };
127
128 template <typename A>
129 typename DwarfFDECache<A>::entry *
130 DwarfFDECache<A>::_buffer = _initialBuffer;
131
132 template <typename A>
133 typename DwarfFDECache<A>::entry *
134 DwarfFDECache<A>::_bufferUsed = _initialBuffer;
135
136 template <typename A>
137 typename DwarfFDECache<A>::entry *
138 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
139
140 template <typename A>
141 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
142
143 template <typename A>
144 RWMutex DwarfFDECache<A>::_lock;
145
146 #ifdef __APPLE__
147 template <typename A>
148 bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
149 #endif
150
151 template <typename A>
152 typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) {
153 pint_t result = 0;
154 _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
155 for (entry *p = _buffer; p < _bufferUsed; ++p) {
156 if ((mh == p->mh) || (mh == kSearchAll)) {
157 if ((p->ip_start <= pc) && (pc < p->ip_end)) {
158 result = p->fde;
159 break;
160 }
161 }
162 }
163 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
164 return result;
165 }
166
167 template <typename A>
168 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
169 pint_t fde) {
170 #if !defined(_LIBUNWIND_NO_HEAP)
171 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
172 if (_bufferUsed >= _bufferEnd) {
173 size_t oldSize = (size_t)(_bufferEnd - _buffer);
174 size_t newSize = oldSize * 4;
175 // Can't use operator new (we are below it).
176 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
177 memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
178 if (_buffer != _initialBuffer)
179 free(_buffer);
180 _buffer = newBuffer;
181 _bufferUsed = &newBuffer[oldSize];
182 _bufferEnd = &newBuffer[newSize];
183 }
184 _bufferUsed->mh = mh;
185 _bufferUsed->ip_start = ip_start;
186 _bufferUsed->ip_end = ip_end;
187 _bufferUsed->fde = fde;
188 ++_bufferUsed;
189 #ifdef __APPLE__
190 if (!_registeredForDyldUnloads) {
191 _dyld_register_func_for_remove_image(&dyldUnloadHook);
192 _registeredForDyldUnloads = true;
193 }
194 #endif
195 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
196 #endif
197 }
198
199 template <typename A>
200 void DwarfFDECache<A>::removeAllIn(pint_t mh) {
201 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
202 entry *d = _buffer;
203 for (const entry *s = _buffer; s < _bufferUsed; ++s) {
204 if (s->mh != mh) {
205 if (d != s)
206 *d = *s;
207 ++d;
208 }
209 }
210 _bufferUsed = d;
211 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
212 }
213
214 #ifdef __APPLE__
215 template <typename A>
216 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
217 removeAllIn((pint_t) mh);
218 }
219 #endif
220
221 template <typename A>
222 void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
223 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
224 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
225 for (entry *p = _buffer; p < _bufferUsed; ++p) {
226 (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
227 }
228 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
229 }
230 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
231
232
233 #define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field))
234
235 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
236 template <typename A> class UnwindSectionHeader {
237 public:
238 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
239 : _addressSpace(addressSpace), _addr(addr) {}
240
241 uint32_t version() const {
242 return _addressSpace.get32(_addr +
243 offsetof(unwind_info_section_header, version));
244 }
245 uint32_t commonEncodingsArraySectionOffset() const {
246 return _addressSpace.get32(_addr +
247 offsetof(unwind_info_section_header,
248 commonEncodingsArraySectionOffset));
249 }
250 uint32_t commonEncodingsArrayCount() const {
251 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
252 commonEncodingsArrayCount));
253 }
254 uint32_t personalityArraySectionOffset() const {
255 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
256 personalityArraySectionOffset));
257 }
258 uint32_t personalityArrayCount() const {
259 return _addressSpace.get32(
260 _addr + offsetof(unwind_info_section_header, personalityArrayCount));
261 }
262 uint32_t indexSectionOffset() const {
263 return _addressSpace.get32(
264 _addr + offsetof(unwind_info_section_header, indexSectionOffset));
265 }
266 uint32_t indexCount() const {
267 return _addressSpace.get32(
268 _addr + offsetof(unwind_info_section_header, indexCount));
269 }
270
271 private:
272 A &_addressSpace;
273 typename A::pint_t _addr;
274 };
275
276 template <typename A> class UnwindSectionIndexArray {
277 public:
278 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
279 : _addressSpace(addressSpace), _addr(addr) {}
280
281 uint32_t functionOffset(uint32_t index) const {
282 return _addressSpace.get32(
283 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
284 functionOffset));
285 }
286 uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
287 return _addressSpace.get32(
288 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
289 secondLevelPagesSectionOffset));
290 }
291 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
292 return _addressSpace.get32(
293 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
294 lsdaIndexArraySectionOffset));
295 }
296
297 private:
298 A &_addressSpace;
299 typename A::pint_t _addr;
300 };
301
302 template <typename A> class UnwindSectionRegularPageHeader {
303 public:
304 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
305 : _addressSpace(addressSpace), _addr(addr) {}
306
307 uint32_t kind() const {
308 return _addressSpace.get32(
309 _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
310 }
311 uint16_t entryPageOffset() const {
312 return _addressSpace.get16(
313 _addr + offsetof(unwind_info_regular_second_level_page_header,
314 entryPageOffset));
315 }
316 uint16_t entryCount() const {
317 return _addressSpace.get16(
318 _addr +
319 offsetof(unwind_info_regular_second_level_page_header, entryCount));
320 }
321
322 private:
323 A &_addressSpace;
324 typename A::pint_t _addr;
325 };
326
327 template <typename A> class UnwindSectionRegularArray {
328 public:
329 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
330 : _addressSpace(addressSpace), _addr(addr) {}
331
332 uint32_t functionOffset(uint32_t index) const {
333 return _addressSpace.get32(
334 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
335 functionOffset));
336 }
337 uint32_t encoding(uint32_t index) const {
338 return _addressSpace.get32(
339 _addr +
340 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
341 }
342
343 private:
344 A &_addressSpace;
345 typename A::pint_t _addr;
346 };
347
348 template <typename A> class UnwindSectionCompressedPageHeader {
349 public:
350 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
351 : _addressSpace(addressSpace), _addr(addr) {}
352
353 uint32_t kind() const {
354 return _addressSpace.get32(
355 _addr +
356 offsetof(unwind_info_compressed_second_level_page_header, kind));
357 }
358 uint16_t entryPageOffset() const {
359 return _addressSpace.get16(
360 _addr + offsetof(unwind_info_compressed_second_level_page_header,
361 entryPageOffset));
362 }
363 uint16_t entryCount() const {
364 return _addressSpace.get16(
365 _addr +
366 offsetof(unwind_info_compressed_second_level_page_header, entryCount));
367 }
368 uint16_t encodingsPageOffset() const {
369 return _addressSpace.get16(
370 _addr + offsetof(unwind_info_compressed_second_level_page_header,
371 encodingsPageOffset));
372 }
373 uint16_t encodingsCount() const {
374 return _addressSpace.get16(
375 _addr + offsetof(unwind_info_compressed_second_level_page_header,
376 encodingsCount));
377 }
378
379 private:
380 A &_addressSpace;
381 typename A::pint_t _addr;
382 };
383
384 template <typename A> class UnwindSectionCompressedArray {
385 public:
386 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
387 : _addressSpace(addressSpace), _addr(addr) {}
388
389 uint32_t functionOffset(uint32_t index) const {
390 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
391 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
392 }
393 uint16_t encodingIndex(uint32_t index) const {
394 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
395 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
396 }
397
398 private:
399 A &_addressSpace;
400 typename A::pint_t _addr;
401 };
402
403 template <typename A> class UnwindSectionLsdaArray {
404 public:
405 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
406 : _addressSpace(addressSpace), _addr(addr) {}
407
408 uint32_t functionOffset(uint32_t index) const {
409 return _addressSpace.get32(
410 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
411 index, functionOffset));
412 }
413 uint32_t lsdaOffset(uint32_t index) const {
414 return _addressSpace.get32(
415 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
416 index, lsdaOffset));
417 }
418
419 private:
420 A &_addressSpace;
421 typename A::pint_t _addr;
422 };
423 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
424
425 class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
426 public:
427 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
428 // This avoids an unnecessary dependency to libc++abi.
429 void operator delete(void *, size_t) {}
430
431 virtual ~AbstractUnwindCursor() {}
432 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
433 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
434 virtual void setReg(int, unw_word_t) {
435 _LIBUNWIND_ABORT("setReg not implemented");
436 }
437 virtual bool validFloatReg(int) {
438 _LIBUNWIND_ABORT("validFloatReg not implemented");
439 }
440 virtual unw_fpreg_t getFloatReg(int) {
441 _LIBUNWIND_ABORT("getFloatReg not implemented");
442 }
443 virtual void setFloatReg(int, unw_fpreg_t) {
444 _LIBUNWIND_ABORT("setFloatReg not implemented");
445 }
446 virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); }
447 virtual void getInfo(unw_proc_info_t *) {
448 _LIBUNWIND_ABORT("getInfo not implemented");
449 }
450 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
451 virtual bool isSignalFrame() {
452 _LIBUNWIND_ABORT("isSignalFrame not implemented");
453 }
454 virtual bool getFunctionName(char *, size_t, unw_word_t *) {
455 _LIBUNWIND_ABORT("getFunctionName not implemented");
456 }
457 virtual void setInfoBasedOnIPRegister(bool = false) {
458 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
459 }
460 virtual const char *getRegisterName(int) {
461 _LIBUNWIND_ABORT("getRegisterName not implemented");
462 }
463 #ifdef __arm__
464 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
465 #endif
466
467 #ifdef _AIX
468 virtual uintptr_t getDataRelBase() {
469 _LIBUNWIND_ABORT("getDataRelBase not implemented");
470 }
471 #endif
472
473 #if defined(_LIBUNWIND_USE_CET)
474 virtual void *get_registers() {
475 _LIBUNWIND_ABORT("get_registers not implemented");
476 }
477 #endif
478 };
479
480 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
481
482 /// \c UnwindCursor contains all state (including all register values) during
483 /// an unwind. This is normally stack-allocated inside a unw_cursor_t.
484 template <typename A, typename R>
485 class UnwindCursor : public AbstractUnwindCursor {
486 typedef typename A::pint_t pint_t;
487 public:
488 UnwindCursor(unw_context_t *context, A &as);
489 UnwindCursor(CONTEXT *context, A &as);
490 UnwindCursor(A &as, void *threadArg);
491 virtual ~UnwindCursor() {}
492 virtual bool validReg(int);
493 virtual unw_word_t getReg(int);
494 virtual void setReg(int, unw_word_t);
495 virtual bool validFloatReg(int);
496 virtual unw_fpreg_t getFloatReg(int);
497 virtual void setFloatReg(int, unw_fpreg_t);
498 virtual int step(bool = false);
499 virtual void getInfo(unw_proc_info_t *);
500 virtual void jumpto();
501 virtual bool isSignalFrame();
502 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
503 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
504 virtual const char *getRegisterName(int num);
505 #ifdef __arm__
506 virtual void saveVFPAsX();
507 #endif
508
509 DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
510 void setDispatcherContext(DISPATCHER_CONTEXT *disp) {
511 _dispContext = *disp;
512 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
513 if (_dispContext.LanguageHandler) {
514 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
515 } else
516 _info.handler = 0;
517 }
518
519 // libunwind does not and should not depend on C++ library which means that we
520 // need our own definition of inline placement new.
521 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
522
523 private:
524
525 pint_t getLastPC() const { return _dispContext.ControlPc; }
526 void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
527 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
528 #ifdef __arm__
529 // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit.
530 pc &= ~1U;
531 #endif
532 // If pc points exactly at the end of the range, we might resolve the
533 // next function instead. Decrement pc by 1 to fit inside the current
534 // function.
535 pc -= 1;
536 _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
537 &_dispContext.ImageBase,
538 _dispContext.HistoryTable);
539 *base = _dispContext.ImageBase;
540 return _dispContext.FunctionEntry;
541 }
542 bool getInfoFromSEH(pint_t pc);
543 int stepWithSEHData() {
544 _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
545 _dispContext.ImageBase,
546 _dispContext.ControlPc,
547 _dispContext.FunctionEntry,
548 _dispContext.ContextRecord,
549 &_dispContext.HandlerData,
550 &_dispContext.EstablisherFrame,
551 NULL);
552 // Update some fields of the unwind info now, since we have them.
553 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
554 if (_dispContext.LanguageHandler) {
555 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
556 } else
557 _info.handler = 0;
558 return UNW_STEP_SUCCESS;
559 }
560
561 A &_addressSpace;
562 unw_proc_info_t _info;
563 DISPATCHER_CONTEXT _dispContext;
564 CONTEXT _msContext;
565 UNWIND_HISTORY_TABLE _histTable;
566 bool _unwindInfoMissing;
567 };
568
569
570 template <typename A, typename R>
571 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
572 : _addressSpace(as), _unwindInfoMissing(false) {
573 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
574 "UnwindCursor<> does not fit in unw_cursor_t");
575 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
576 "UnwindCursor<> requires more alignment than unw_cursor_t");
577 memset(&_info, 0, sizeof(_info));
578 memset(&_histTable, 0, sizeof(_histTable));
579 memset(&_dispContext, 0, sizeof(_dispContext));
580 _dispContext.ContextRecord = &_msContext;
581 _dispContext.HistoryTable = &_histTable;
582 // Initialize MS context from ours.
583 R r(context);
584 RtlCaptureContext(&_msContext);
585 _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
586 #if defined(_LIBUNWIND_TARGET_X86_64)
587 _msContext.Rax = r.getRegister(UNW_X86_64_RAX);
588 _msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
589 _msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
590 _msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
591 _msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
592 _msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
593 _msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
594 _msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
595 _msContext.R8 = r.getRegister(UNW_X86_64_R8);
596 _msContext.R9 = r.getRegister(UNW_X86_64_R9);
597 _msContext.R10 = r.getRegister(UNW_X86_64_R10);
598 _msContext.R11 = r.getRegister(UNW_X86_64_R11);
599 _msContext.R12 = r.getRegister(UNW_X86_64_R12);
600 _msContext.R13 = r.getRegister(UNW_X86_64_R13);
601 _msContext.R14 = r.getRegister(UNW_X86_64_R14);
602 _msContext.R15 = r.getRegister(UNW_X86_64_R15);
603 _msContext.Rip = r.getRegister(UNW_REG_IP);
604 union {
605 v128 v;
606 M128A m;
607 } t;
608 t.v = r.getVectorRegister(UNW_X86_64_XMM0);
609 _msContext.Xmm0 = t.m;
610 t.v = r.getVectorRegister(UNW_X86_64_XMM1);
611 _msContext.Xmm1 = t.m;
612 t.v = r.getVectorRegister(UNW_X86_64_XMM2);
613 _msContext.Xmm2 = t.m;
614 t.v = r.getVectorRegister(UNW_X86_64_XMM3);
615 _msContext.Xmm3 = t.m;
616 t.v = r.getVectorRegister(UNW_X86_64_XMM4);
617 _msContext.Xmm4 = t.m;
618 t.v = r.getVectorRegister(UNW_X86_64_XMM5);
619 _msContext.Xmm5 = t.m;
620 t.v = r.getVectorRegister(UNW_X86_64_XMM6);
621 _msContext.Xmm6 = t.m;
622 t.v = r.getVectorRegister(UNW_X86_64_XMM7);
623 _msContext.Xmm7 = t.m;
624 t.v = r.getVectorRegister(UNW_X86_64_XMM8);
625 _msContext.Xmm8 = t.m;
626 t.v = r.getVectorRegister(UNW_X86_64_XMM9);
627 _msContext.Xmm9 = t.m;
628 t.v = r.getVectorRegister(UNW_X86_64_XMM10);
629 _msContext.Xmm10 = t.m;
630 t.v = r.getVectorRegister(UNW_X86_64_XMM11);
631 _msContext.Xmm11 = t.m;
632 t.v = r.getVectorRegister(UNW_X86_64_XMM12);
633 _msContext.Xmm12 = t.m;
634 t.v = r.getVectorRegister(UNW_X86_64_XMM13);
635 _msContext.Xmm13 = t.m;
636 t.v = r.getVectorRegister(UNW_X86_64_XMM14);
637 _msContext.Xmm14 = t.m;
638 t.v = r.getVectorRegister(UNW_X86_64_XMM15);
639 _msContext.Xmm15 = t.m;
640 #elif defined(_LIBUNWIND_TARGET_ARM)
641 _msContext.R0 = r.getRegister(UNW_ARM_R0);
642 _msContext.R1 = r.getRegister(UNW_ARM_R1);
643 _msContext.R2 = r.getRegister(UNW_ARM_R2);
644 _msContext.R3 = r.getRegister(UNW_ARM_R3);
645 _msContext.R4 = r.getRegister(UNW_ARM_R4);
646 _msContext.R5 = r.getRegister(UNW_ARM_R5);
647 _msContext.R6 = r.getRegister(UNW_ARM_R6);
648 _msContext.R7 = r.getRegister(UNW_ARM_R7);
649 _msContext.R8 = r.getRegister(UNW_ARM_R8);
650 _msContext.R9 = r.getRegister(UNW_ARM_R9);
651 _msContext.R10 = r.getRegister(UNW_ARM_R10);
652 _msContext.R11 = r.getRegister(UNW_ARM_R11);
653 _msContext.R12 = r.getRegister(UNW_ARM_R12);
654 _msContext.Sp = r.getRegister(UNW_ARM_SP);
655 _msContext.Lr = r.getRegister(UNW_ARM_LR);
656 _msContext.Pc = r.getRegister(UNW_ARM_IP);
657 for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
658 union {
659 uint64_t w;
660 double d;
661 } d;
662 d.d = r.getFloatRegister(i);
663 _msContext.D[i - UNW_ARM_D0] = d.w;
664 }
665 #elif defined(_LIBUNWIND_TARGET_AARCH64)
666 for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
667 _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
668 _msContext.Sp = r.getRegister(UNW_REG_SP);
669 _msContext.Pc = r.getRegister(UNW_REG_IP);
670 for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
671 _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
672 #endif
673 }
674
675 template <typename A, typename R>
676 UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
677 : _addressSpace(as), _unwindInfoMissing(false) {
678 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
679 "UnwindCursor<> does not fit in unw_cursor_t");
680 memset(&_info, 0, sizeof(_info));
681 memset(&_histTable, 0, sizeof(_histTable));
682 memset(&_dispContext, 0, sizeof(_dispContext));
683 _dispContext.ContextRecord = &_msContext;
684 _dispContext.HistoryTable = &_histTable;
685 _msContext = *context;
686 }
687
688
689 template <typename A, typename R>
690 bool UnwindCursor<A, R>::validReg(int regNum) {
691 if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
692 #if defined(_LIBUNWIND_TARGET_X86_64)
693 if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_RIP) return true;
694 #elif defined(_LIBUNWIND_TARGET_ARM)
695 if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
696 regNum == UNW_ARM_RA_AUTH_CODE)
697 return true;
698 #elif defined(_LIBUNWIND_TARGET_AARCH64)
699 if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
700 #endif
701 return false;
702 }
703
704 template <typename A, typename R>
705 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
706 switch (regNum) {
707 #if defined(_LIBUNWIND_TARGET_X86_64)
708 case UNW_X86_64_RIP:
709 case UNW_REG_IP: return _msContext.Rip;
710 case UNW_X86_64_RAX: return _msContext.Rax;
711 case UNW_X86_64_RDX: return _msContext.Rdx;
712 case UNW_X86_64_RCX: return _msContext.Rcx;
713 case UNW_X86_64_RBX: return _msContext.Rbx;
714 case UNW_REG_SP:
715 case UNW_X86_64_RSP: return _msContext.Rsp;
716 case UNW_X86_64_RBP: return _msContext.Rbp;
717 case UNW_X86_64_RSI: return _msContext.Rsi;
718 case UNW_X86_64_RDI: return _msContext.Rdi;
719 case UNW_X86_64_R8: return _msContext.R8;
720 case UNW_X86_64_R9: return _msContext.R9;
721 case UNW_X86_64_R10: return _msContext.R10;
722 case UNW_X86_64_R11: return _msContext.R11;
723 case UNW_X86_64_R12: return _msContext.R12;
724 case UNW_X86_64_R13: return _msContext.R13;
725 case UNW_X86_64_R14: return _msContext.R14;
726 case UNW_X86_64_R15: return _msContext.R15;
727 #elif defined(_LIBUNWIND_TARGET_ARM)
728 case UNW_ARM_R0: return _msContext.R0;
729 case UNW_ARM_R1: return _msContext.R1;
730 case UNW_ARM_R2: return _msContext.R2;
731 case UNW_ARM_R3: return _msContext.R3;
732 case UNW_ARM_R4: return _msContext.R4;
733 case UNW_ARM_R5: return _msContext.R5;
734 case UNW_ARM_R6: return _msContext.R6;
735 case UNW_ARM_R7: return _msContext.R7;
736 case UNW_ARM_R8: return _msContext.R8;
737 case UNW_ARM_R9: return _msContext.R9;
738 case UNW_ARM_R10: return _msContext.R10;
739 case UNW_ARM_R11: return _msContext.R11;
740 case UNW_ARM_R12: return _msContext.R12;
741 case UNW_REG_SP:
742 case UNW_ARM_SP: return _msContext.Sp;
743 case UNW_ARM_LR: return _msContext.Lr;
744 case UNW_REG_IP:
745 case UNW_ARM_IP: return _msContext.Pc;
746 #elif defined(_LIBUNWIND_TARGET_AARCH64)
747 case UNW_REG_SP: return _msContext.Sp;
748 case UNW_REG_IP: return _msContext.Pc;
749 default: return _msContext.X[regNum - UNW_AARCH64_X0];
750 #endif
751 }
752 _LIBUNWIND_ABORT("unsupported register");
753 }
754
755 template <typename A, typename R>
756 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
757 switch (regNum) {
758 #if defined(_LIBUNWIND_TARGET_X86_64)
759 case UNW_X86_64_RIP:
760 case UNW_REG_IP: _msContext.Rip = value; break;
761 case UNW_X86_64_RAX: _msContext.Rax = value; break;
762 case UNW_X86_64_RDX: _msContext.Rdx = value; break;
763 case UNW_X86_64_RCX: _msContext.Rcx = value; break;
764 case UNW_X86_64_RBX: _msContext.Rbx = value; break;
765 case UNW_REG_SP:
766 case UNW_X86_64_RSP: _msContext.Rsp = value; break;
767 case UNW_X86_64_RBP: _msContext.Rbp = value; break;
768 case UNW_X86_64_RSI: _msContext.Rsi = value; break;
769 case UNW_X86_64_RDI: _msContext.Rdi = value; break;
770 case UNW_X86_64_R8: _msContext.R8 = value; break;
771 case UNW_X86_64_R9: _msContext.R9 = value; break;
772 case UNW_X86_64_R10: _msContext.R10 = value; break;
773 case UNW_X86_64_R11: _msContext.R11 = value; break;
774 case UNW_X86_64_R12: _msContext.R12 = value; break;
775 case UNW_X86_64_R13: _msContext.R13 = value; break;
776 case UNW_X86_64_R14: _msContext.R14 = value; break;
777 case UNW_X86_64_R15: _msContext.R15 = value; break;
778 #elif defined(_LIBUNWIND_TARGET_ARM)
779 case UNW_ARM_R0: _msContext.R0 = value; break;
780 case UNW_ARM_R1: _msContext.R1 = value; break;
781 case UNW_ARM_R2: _msContext.R2 = value; break;
782 case UNW_ARM_R3: _msContext.R3 = value; break;
783 case UNW_ARM_R4: _msContext.R4 = value; break;
784 case UNW_ARM_R5: _msContext.R5 = value; break;
785 case UNW_ARM_R6: _msContext.R6 = value; break;
786 case UNW_ARM_R7: _msContext.R7 = value; break;
787 case UNW_ARM_R8: _msContext.R8 = value; break;
788 case UNW_ARM_R9: _msContext.R9 = value; break;
789 case UNW_ARM_R10: _msContext.R10 = value; break;
790 case UNW_ARM_R11: _msContext.R11 = value; break;
791 case UNW_ARM_R12: _msContext.R12 = value; break;
792 case UNW_REG_SP:
793 case UNW_ARM_SP: _msContext.Sp = value; break;
794 case UNW_ARM_LR: _msContext.Lr = value; break;
795 case UNW_REG_IP:
796 case UNW_ARM_IP: _msContext.Pc = value; break;
797 #elif defined(_LIBUNWIND_TARGET_AARCH64)
798 case UNW_REG_SP: _msContext.Sp = value; break;
799 case UNW_REG_IP: _msContext.Pc = value; break;
800 case UNW_AARCH64_X0:
801 case UNW_AARCH64_X1:
802 case UNW_AARCH64_X2:
803 case UNW_AARCH64_X3:
804 case UNW_AARCH64_X4:
805 case UNW_AARCH64_X5:
806 case UNW_AARCH64_X6:
807 case UNW_AARCH64_X7:
808 case UNW_AARCH64_X8:
809 case UNW_AARCH64_X9:
810 case UNW_AARCH64_X10:
811 case UNW_AARCH64_X11:
812 case UNW_AARCH64_X12:
813 case UNW_AARCH64_X13:
814 case UNW_AARCH64_X14:
815 case UNW_AARCH64_X15:
816 case UNW_AARCH64_X16:
817 case UNW_AARCH64_X17:
818 case UNW_AARCH64_X18:
819 case UNW_AARCH64_X19:
820 case UNW_AARCH64_X20:
821 case UNW_AARCH64_X21:
822 case UNW_AARCH64_X22:
823 case UNW_AARCH64_X23:
824 case UNW_AARCH64_X24:
825 case UNW_AARCH64_X25:
826 case UNW_AARCH64_X26:
827 case UNW_AARCH64_X27:
828 case UNW_AARCH64_X28:
829 case UNW_AARCH64_FP:
830 case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
831 #endif
832 default:
833 _LIBUNWIND_ABORT("unsupported register");
834 }
835 }
836
837 template <typename A, typename R>
838 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
839 #if defined(_LIBUNWIND_TARGET_ARM)
840 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
841 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
842 #elif defined(_LIBUNWIND_TARGET_AARCH64)
843 if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
844 #else
845 (void)regNum;
846 #endif
847 return false;
848 }
849
850 template <typename A, typename R>
851 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
852 #if defined(_LIBUNWIND_TARGET_ARM)
853 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
854 union {
855 uint32_t w;
856 float f;
857 } d;
858 d.w = _msContext.S[regNum - UNW_ARM_S0];
859 return d.f;
860 }
861 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
862 union {
863 uint64_t w;
864 double d;
865 } d;
866 d.w = _msContext.D[regNum - UNW_ARM_D0];
867 return d.d;
868 }
869 _LIBUNWIND_ABORT("unsupported float register");
870 #elif defined(_LIBUNWIND_TARGET_AARCH64)
871 return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
872 #else
873 (void)regNum;
874 _LIBUNWIND_ABORT("float registers unimplemented");
875 #endif
876 }
877
878 template <typename A, typename R>
879 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
880 #if defined(_LIBUNWIND_TARGET_ARM)
881 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
882 union {
883 uint32_t w;
884 float f;
885 } d;
886 d.f = (float)value;
887 _msContext.S[regNum - UNW_ARM_S0] = d.w;
888 }
889 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
890 union {
891 uint64_t w;
892 double d;
893 } d;
894 d.d = value;
895 _msContext.D[regNum - UNW_ARM_D0] = d.w;
896 }
897 _LIBUNWIND_ABORT("unsupported float register");
898 #elif defined(_LIBUNWIND_TARGET_AARCH64)
899 _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
900 #else
901 (void)regNum;
902 (void)value;
903 _LIBUNWIND_ABORT("float registers unimplemented");
904 #endif
905 }
906
907 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
908 RtlRestoreContext(&_msContext, nullptr);
909 }
910
911 #ifdef __arm__
912 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
913 #endif
914
915 template <typename A, typename R>
916 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
917 return R::getRegisterName(regNum);
918 }
919
920 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
921 return false;
922 }
923
924 #else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
925
926 /// UnwindCursor contains all state (including all register values) during
927 /// an unwind. This is normally stack allocated inside a unw_cursor_t.
928 template <typename A, typename R>
929 class UnwindCursor : public AbstractUnwindCursor{
930 typedef typename A::pint_t pint_t;
931 public:
932 UnwindCursor(unw_context_t *context, A &as);
933 UnwindCursor(A &as, void *threadArg);
934 virtual ~UnwindCursor() {}
935 virtual bool validReg(int);
936 virtual unw_word_t getReg(int);
937 virtual void setReg(int, unw_word_t);
938 virtual bool validFloatReg(int);
939 virtual unw_fpreg_t getFloatReg(int);
940 virtual void setFloatReg(int, unw_fpreg_t);
941 virtual int step(bool stage2 = false);
942 virtual void getInfo(unw_proc_info_t *);
943 virtual void jumpto();
944 virtual bool isSignalFrame();
945 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
946 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
947 virtual const char *getRegisterName(int num);
948 #ifdef __arm__
949 virtual void saveVFPAsX();
950 #endif
951
952 #ifdef _AIX
953 virtual uintptr_t getDataRelBase();
954 #endif
955
956 #if defined(_LIBUNWIND_USE_CET)
957 virtual void *get_registers() { return &_registers; }
958 #endif
959
960 // libunwind does not and should not depend on C++ library which means that we
961 // need our own definition of inline placement new.
962 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
963
964 private:
965
966 #if defined(_LIBUNWIND_ARM_EHABI)
967 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections &sects);
968
969 int stepWithEHABI() {
970 size_t len = 0;
971 size_t off = 0;
972 // FIXME: Calling decode_eht_entry() here is violating the libunwind
973 // abstraction layer.
974 const uint32_t *ehtp =
975 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
976 &off, &len);
977 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
978 _URC_CONTINUE_UNWIND)
979 return UNW_STEP_END;
980 return UNW_STEP_SUCCESS;
981 }
982 #endif
983
984 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
985 bool setInfoForSigReturn() {
986 R dummy;
987 return setInfoForSigReturn(dummy);
988 }
989 int stepThroughSigReturn() {
990 R dummy;
991 return stepThroughSigReturn(dummy);
992 }
993 #if defined(_LIBUNWIND_TARGET_AARCH64)
994 bool setInfoForSigReturn(Registers_arm64 &);
995 int stepThroughSigReturn(Registers_arm64 &);
996 #endif
997 #if defined(_LIBUNWIND_TARGET_RISCV)
998 bool setInfoForSigReturn(Registers_riscv &);
999 int stepThroughSigReturn(Registers_riscv &);
1000 #endif
1001 #if defined(_LIBUNWIND_TARGET_S390X)
1002 bool setInfoForSigReturn(Registers_s390x &);
1003 int stepThroughSigReturn(Registers_s390x &);
1004 #endif
1005 template <typename Registers> bool setInfoForSigReturn(Registers &) {
1006 return false;
1007 }
1008 template <typename Registers> int stepThroughSigReturn(Registers &) {
1009 return UNW_STEP_END;
1010 }
1011 #endif
1012
1013 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1014 bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1015 const typename CFI_Parser<A>::CIE_Info &cieInfo,
1016 pint_t pc, uintptr_t dso_base);
1017 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections &sects,
1018 uint32_t fdeSectionOffsetHint=0);
1019 int stepWithDwarfFDE(bool stage2) {
1020 return DwarfInstructions<A, R>::stepWithDwarf(
1021 _addressSpace, (pint_t)this->getReg(UNW_REG_IP),
1022 (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2);
1023 }
1024 #endif
1025
1026 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1027 bool getInfoFromCompactEncodingSection(pint_t pc,
1028 const UnwindInfoSections &sects);
1029 int stepWithCompactEncoding(bool stage2 = false) {
1030 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1031 if ( compactSaysUseDwarf() )
1032 return stepWithDwarfFDE(stage2);
1033 #endif
1034 R dummy;
1035 return stepWithCompactEncoding(dummy);
1036 }
1037
1038 #if defined(_LIBUNWIND_TARGET_X86_64)
1039 int stepWithCompactEncoding(Registers_x86_64 &) {
1040 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
1041 _info.format, _info.start_ip, _addressSpace, _registers);
1042 }
1043 #endif
1044
1045 #if defined(_LIBUNWIND_TARGET_I386)
1046 int stepWithCompactEncoding(Registers_x86 &) {
1047 return CompactUnwinder_x86<A>::stepWithCompactEncoding(
1048 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
1049 }
1050 #endif
1051
1052 #if defined(_LIBUNWIND_TARGET_PPC)
1053 int stepWithCompactEncoding(Registers_ppc &) {
1054 return UNW_EINVAL;
1055 }
1056 #endif
1057
1058 #if defined(_LIBUNWIND_TARGET_PPC64)
1059 int stepWithCompactEncoding(Registers_ppc64 &) {
1060 return UNW_EINVAL;
1061 }
1062 #endif
1063
1064
1065 #if defined(_LIBUNWIND_TARGET_AARCH64)
1066 int stepWithCompactEncoding(Registers_arm64 &) {
1067 return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
1068 _info.format, _info.start_ip, _addressSpace, _registers);
1069 }
1070 #endif
1071
1072 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
1073 int stepWithCompactEncoding(Registers_mips_o32 &) {
1074 return UNW_EINVAL;
1075 }
1076 #endif
1077
1078 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
1079 int stepWithCompactEncoding(Registers_mips_newabi &) {
1080 return UNW_EINVAL;
1081 }
1082 #endif
1083
1084 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
1085 int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; }
1086 #endif
1087
1088 #if defined(_LIBUNWIND_TARGET_SPARC)
1089 int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
1090 #endif
1091
1092 #if defined(_LIBUNWIND_TARGET_SPARC64)
1093 int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
1094 #endif
1095
1096 #if defined (_LIBUNWIND_TARGET_RISCV)
1097 int stepWithCompactEncoding(Registers_riscv &) {
1098 return UNW_EINVAL;
1099 }
1100 #endif
1101
1102 bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
1103 R dummy;
1104 return compactSaysUseDwarf(dummy, offset);
1105 }
1106
1107 #if defined(_LIBUNWIND_TARGET_X86_64)
1108 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
1109 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
1110 if (offset)
1111 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
1112 return true;
1113 }
1114 return false;
1115 }
1116 #endif
1117
1118 #if defined(_LIBUNWIND_TARGET_I386)
1119 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
1120 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
1121 if (offset)
1122 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
1123 return true;
1124 }
1125 return false;
1126 }
1127 #endif
1128
1129 #if defined(_LIBUNWIND_TARGET_PPC)
1130 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
1131 return true;
1132 }
1133 #endif
1134
1135 #if defined(_LIBUNWIND_TARGET_PPC64)
1136 bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
1137 return true;
1138 }
1139 #endif
1140
1141 #if defined(_LIBUNWIND_TARGET_AARCH64)
1142 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
1143 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
1144 if (offset)
1145 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
1146 return true;
1147 }
1148 return false;
1149 }
1150 #endif
1151
1152 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
1153 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
1154 return true;
1155 }
1156 #endif
1157
1158 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
1159 bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
1160 return true;
1161 }
1162 #endif
1163
1164 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
1165 bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const {
1166 return true;
1167 }
1168 #endif
1169
1170 #if defined(_LIBUNWIND_TARGET_SPARC)
1171 bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
1172 #endif
1173
1174 #if defined(_LIBUNWIND_TARGET_SPARC64)
1175 bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
1176 return true;
1177 }
1178 #endif
1179
1180 #if defined (_LIBUNWIND_TARGET_RISCV)
1181 bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
1182 return true;
1183 }
1184 #endif
1185
1186 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1187
1188 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1189 compact_unwind_encoding_t dwarfEncoding() const {
1190 R dummy;
1191 return dwarfEncoding(dummy);
1192 }
1193
1194 #if defined(_LIBUNWIND_TARGET_X86_64)
1195 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
1196 return UNWIND_X86_64_MODE_DWARF;
1197 }
1198 #endif
1199
1200 #if defined(_LIBUNWIND_TARGET_I386)
1201 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
1202 return UNWIND_X86_MODE_DWARF;
1203 }
1204 #endif
1205
1206 #if defined(_LIBUNWIND_TARGET_PPC)
1207 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
1208 return 0;
1209 }
1210 #endif
1211
1212 #if defined(_LIBUNWIND_TARGET_PPC64)
1213 compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
1214 return 0;
1215 }
1216 #endif
1217
1218 #if defined(_LIBUNWIND_TARGET_AARCH64)
1219 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
1220 return UNWIND_ARM64_MODE_DWARF;
1221 }
1222 #endif
1223
1224 #if defined(_LIBUNWIND_TARGET_ARM)
1225 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
1226 return 0;
1227 }
1228 #endif
1229
1230 #if defined (_LIBUNWIND_TARGET_OR1K)
1231 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
1232 return 0;
1233 }
1234 #endif
1235
1236 #if defined (_LIBUNWIND_TARGET_HEXAGON)
1237 compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
1238 return 0;
1239 }
1240 #endif
1241
1242 #if defined (_LIBUNWIND_TARGET_MIPS_O32)
1243 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
1244 return 0;
1245 }
1246 #endif
1247
1248 #if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
1249 compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
1250 return 0;
1251 }
1252 #endif
1253
1254 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
1255 compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const {
1256 return 0;
1257 }
1258 #endif
1259
1260 #if defined(_LIBUNWIND_TARGET_SPARC)
1261 compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
1262 #endif
1263
1264 #if defined(_LIBUNWIND_TARGET_SPARC64)
1265 compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
1266 return 0;
1267 }
1268 #endif
1269
1270 #if defined (_LIBUNWIND_TARGET_RISCV)
1271 compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
1272 return 0;
1273 }
1274 #endif
1275
1276 #if defined (_LIBUNWIND_TARGET_S390X)
1277 compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const {
1278 return 0;
1279 }
1280 #endif
1281
1282 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1283
1284 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1285 // For runtime environments using SEH unwind data without Windows runtime
1286 // support.
1287 pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
1288 void setLastPC(pint_t pc) { /* FIXME: Implement */ }
1289 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
1290 /* FIXME: Implement */
1291 *base = 0;
1292 return nullptr;
1293 }
1294 bool getInfoFromSEH(pint_t pc);
1295 int stepWithSEHData() { /* FIXME: Implement */ return 0; }
1296 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1297
1298 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1299 bool getInfoFromTBTable(pint_t pc, R &registers);
1300 int stepWithTBTable(pint_t pc, tbtable *TBTable, R &registers,
1301 bool &isSignalFrame);
1302 int stepWithTBTableData() {
1303 return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
1304 reinterpret_cast<tbtable *>(_info.unwind_info),
1305 _registers, _isSignalFrame);
1306 }
1307 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1308
1309 A &_addressSpace;
1310 R _registers;
1311 unw_proc_info_t _info;
1312 bool _unwindInfoMissing;
1313 bool _isSignalFrame;
1314 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
1315 bool _isSigReturn = false;
1316 #endif
1317 };
1318
1319
1320 template <typename A, typename R>
1321 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
1322 : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
1323 _isSignalFrame(false) {
1324 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
1325 "UnwindCursor<> does not fit in unw_cursor_t");
1326 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
1327 "UnwindCursor<> requires more alignment than unw_cursor_t");
1328 memset(&_info, 0, sizeof(_info));
1329 }
1330
1331 template <typename A, typename R>
1332 UnwindCursor<A, R>::UnwindCursor(A &as, void *)
1333 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
1334 memset(&_info, 0, sizeof(_info));
1335 // FIXME
1336 // fill in _registers from thread arg
1337 }
1338
1339
1340 template <typename A, typename R>
1341 bool UnwindCursor<A, R>::validReg(int regNum) {
1342 return _registers.validRegister(regNum);
1343 }
1344
1345 template <typename A, typename R>
1346 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
1347 return _registers.getRegister(regNum);
1348 }
1349
1350 template <typename A, typename R>
1351 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
1352 _registers.setRegister(regNum, (typename A::pint_t)value);
1353 }
1354
1355 template <typename A, typename R>
1356 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
1357 return _registers.validFloatRegister(regNum);
1358 }
1359
1360 template <typename A, typename R>
1361 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
1362 return _registers.getFloatRegister(regNum);
1363 }
1364
1365 template <typename A, typename R>
1366 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
1367 _registers.setFloatRegister(regNum, value);
1368 }
1369
1370 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
1371 _registers.jumpto();
1372 }
1373
1374 #ifdef __arm__
1375 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
1376 _registers.saveVFPAsX();
1377 }
1378 #endif
1379
1380 #ifdef _AIX
1381 template <typename A, typename R>
1382 uintptr_t UnwindCursor<A, R>::getDataRelBase() {
1383 return reinterpret_cast<uintptr_t>(_info.extra);
1384 }
1385 #endif
1386
1387 template <typename A, typename R>
1388 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
1389 return _registers.getRegisterName(regNum);
1390 }
1391
1392 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
1393 return _isSignalFrame;
1394 }
1395
1396 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1397
1398 #if defined(_LIBUNWIND_ARM_EHABI)
1399 template<typename A>
1400 struct EHABISectionIterator {
1401 typedef EHABISectionIterator _Self;
1402
1403 typedef typename A::pint_t value_type;
1404 typedef typename A::pint_t* pointer;
1405 typedef typename A::pint_t& reference;
1406 typedef size_t size_type;
1407 typedef size_t difference_type;
1408
1409 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
1410 return _Self(addressSpace, sects, 0);
1411 }
1412 static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
1413 return _Self(addressSpace, sects,
1414 sects.arm_section_length / sizeof(EHABIIndexEntry));
1415 }
1416
1417 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
1418 : _i(i), _addressSpace(&addressSpace), _sects(&sects) {}
1419
1420 _Self& operator++() { ++_i; return *this; }
1421 _Self& operator+=(size_t a) { _i += a; return *this; }
1422 _Self& operator--() { assert(_i > 0); --_i; return *this; }
1423 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
1424
1425 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
1426 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
1427
1428 size_t operator-(const _Self& other) const { return _i - other._i; }
1429
1430 bool operator==(const _Self& other) const {
1431 assert(_addressSpace == other._addressSpace);
1432 assert(_sects == other._sects);
1433 return _i == other._i;
1434 }
1435
1436 bool operator!=(const _Self& other) const {
1437 assert(_addressSpace == other._addressSpace);
1438 assert(_sects == other._sects);
1439 return _i != other._i;
1440 }
1441
1442 typename A::pint_t operator*() const { return functionAddress(); }
1443
1444 typename A::pint_t functionAddress() const {
1445 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1446 EHABIIndexEntry, _i, functionOffset);
1447 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
1448 }
1449
1450 typename A::pint_t dataAddress() {
1451 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1452 EHABIIndexEntry, _i, data);
1453 return indexAddr;
1454 }
1455
1456 private:
1457 size_t _i;
1458 A* _addressSpace;
1459 const UnwindInfoSections* _sects;
1460 };
1461
1462 namespace {
1463
1464 template <typename A>
1465 EHABISectionIterator<A> EHABISectionUpperBound(
1466 EHABISectionIterator<A> first,
1467 EHABISectionIterator<A> last,
1468 typename A::pint_t value) {
1469 size_t len = last - first;
1470 while (len > 0) {
1471 size_t l2 = len / 2;
1472 EHABISectionIterator<A> m = first + l2;
1473 if (value < *m) {
1474 len = l2;
1475 } else {
1476 first = ++m;
1477 len -= l2 + 1;
1478 }
1479 }
1480 return first;
1481 }
1482
1483 }
1484
1485 template <typename A, typename R>
1486 bool UnwindCursor<A, R>::getInfoFromEHABISection(
1487 pint_t pc,
1488 const UnwindInfoSections &sects) {
1489 EHABISectionIterator<A> begin =
1490 EHABISectionIterator<A>::begin(_addressSpace, sects);
1491 EHABISectionIterator<A> end =
1492 EHABISectionIterator<A>::end(_addressSpace, sects);
1493 if (begin == end)
1494 return false;
1495
1496 EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
1497 if (itNextPC == begin)
1498 return false;
1499 EHABISectionIterator<A> itThisPC = itNextPC - 1;
1500
1501 pint_t thisPC = itThisPC.functionAddress();
1502 // If an exception is thrown from a function, corresponding to the last entry
1503 // in the table, we don't really know the function extent and have to choose a
1504 // value for nextPC. Choosing max() will allow the range check during trace to
1505 // succeed.
1506 pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
1507 pint_t indexDataAddr = itThisPC.dataAddress();
1508
1509 if (indexDataAddr == 0)
1510 return false;
1511
1512 uint32_t indexData = _addressSpace.get32(indexDataAddr);
1513 if (indexData == UNW_EXIDX_CANTUNWIND)
1514 return false;
1515
1516 // If the high bit is set, the exception handling table entry is inline inside
1517 // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
1518 // the table points at an offset in the exception handling table (section 5
1519 // EHABI).
1520 pint_t exceptionTableAddr;
1521 uint32_t exceptionTableData;
1522 bool isSingleWordEHT;
1523 if (indexData & 0x80000000) {
1524 exceptionTableAddr = indexDataAddr;
1525 // TODO(ajwong): Should this data be 0?
1526 exceptionTableData = indexData;
1527 isSingleWordEHT = true;
1528 } else {
1529 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
1530 exceptionTableData = _addressSpace.get32(exceptionTableAddr);
1531 isSingleWordEHT = false;
1532 }
1533
1534 // Now we know the 3 things:
1535 // exceptionTableAddr -- exception handler table entry.
1536 // exceptionTableData -- the data inside the first word of the eht entry.
1537 // isSingleWordEHT -- whether the entry is in the index.
1538 unw_word_t personalityRoutine = 0xbadf00d;
1539 bool scope32 = false;
1540 uintptr_t lsda;
1541
1542 // If the high bit in the exception handling table entry is set, the entry is
1543 // in compact form (section 6.3 EHABI).
1544 if (exceptionTableData & 0x80000000) {
1545 // Grab the index of the personality routine from the compact form.
1546 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
1547 uint32_t extraWords = 0;
1548 switch (choice) {
1549 case 0:
1550 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
1551 extraWords = 0;
1552 scope32 = false;
1553 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
1554 break;
1555 case 1:
1556 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
1557 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1558 scope32 = false;
1559 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1560 break;
1561 case 2:
1562 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
1563 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1564 scope32 = true;
1565 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1566 break;
1567 default:
1568 _LIBUNWIND_ABORT("unknown personality routine");
1569 return false;
1570 }
1571
1572 if (isSingleWordEHT) {
1573 if (extraWords != 0) {
1574 _LIBUNWIND_ABORT("index inlined table detected but pr function "
1575 "requires extra words");
1576 return false;
1577 }
1578 }
1579 } else {
1580 pint_t personalityAddr =
1581 exceptionTableAddr + signExtendPrel31(exceptionTableData);
1582 personalityRoutine = personalityAddr;
1583
1584 // ARM EHABI # 6.2, # 9.2
1585 //
1586 // +---- ehtp
1587 // v
1588 // +--------------------------------------+
1589 // | +--------+--------+--------+-------+ |
1590 // | |0| prel31 to personalityRoutine | |
1591 // | +--------+--------+--------+-------+ |
1592 // | | N | unwind opcodes | | <-- UnwindData
1593 // | +--------+--------+--------+-------+ |
1594 // | | Word 2 unwind opcodes | |
1595 // | +--------+--------+--------+-------+ |
1596 // | ... |
1597 // | +--------+--------+--------+-------+ |
1598 // | | Word N unwind opcodes | |
1599 // | +--------+--------+--------+-------+ |
1600 // | | LSDA | | <-- lsda
1601 // | | ... | |
1602 // | +--------+--------+--------+-------+ |
1603 // +--------------------------------------+
1604
1605 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
1606 uint32_t FirstDataWord = *UnwindData;
1607 size_t N = ((FirstDataWord >> 24) & 0xff);
1608 size_t NDataWords = N + 1;
1609 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
1610 }
1611
1612 _info.start_ip = thisPC;
1613 _info.end_ip = nextPC;
1614 _info.handler = personalityRoutine;
1615 _info.unwind_info = exceptionTableAddr;
1616 _info.lsda = lsda;
1617 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
1618 _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum?
1619
1620 return true;
1621 }
1622 #endif
1623
1624 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1625 template <typename A, typename R>
1626 bool UnwindCursor<A, R>::getInfoFromFdeCie(
1627 const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1628 const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc,
1629 uintptr_t dso_base) {
1630 typename CFI_Parser<A>::PrologInfo prolog;
1631 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
1632 R::getArch(), &prolog)) {
1633 // Save off parsed FDE info
1634 _info.start_ip = fdeInfo.pcStart;
1635 _info.end_ip = fdeInfo.pcEnd;
1636 _info.lsda = fdeInfo.lsda;
1637 _info.handler = cieInfo.personality;
1638 // Some frameless functions need SP altered when resuming in function, so
1639 // propagate spExtraArgSize.
1640 _info.gp = prolog.spExtraArgSize;
1641 _info.flags = 0;
1642 _info.format = dwarfEncoding();
1643 _info.unwind_info = fdeInfo.fdeStart;
1644 _info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength);
1645 _info.extra = static_cast<unw_word_t>(dso_base);
1646 return true;
1647 }
1648 return false;
1649 }
1650
1651 template <typename A, typename R>
1652 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
1653 const UnwindInfoSections &sects,
1654 uint32_t fdeSectionOffsetHint) {
1655 typename CFI_Parser<A>::FDE_Info fdeInfo;
1656 typename CFI_Parser<A>::CIE_Info cieInfo;
1657 bool foundFDE = false;
1658 bool foundInCache = false;
1659 // If compact encoding table gave offset into dwarf section, go directly there
1660 if (fdeSectionOffsetHint != 0) {
1661 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1662 sects.dwarf_section_length,
1663 sects.dwarf_section + fdeSectionOffsetHint,
1664 &fdeInfo, &cieInfo);
1665 }
1666 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1667 if (!foundFDE && (sects.dwarf_index_section != 0)) {
1668 foundFDE = EHHeaderParser<A>::findFDE(
1669 _addressSpace, pc, sects.dwarf_index_section,
1670 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
1671 }
1672 #endif
1673 if (!foundFDE) {
1674 // otherwise, search cache of previously found FDEs.
1675 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
1676 if (cachedFDE != 0) {
1677 foundFDE =
1678 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1679 sects.dwarf_section_length,
1680 cachedFDE, &fdeInfo, &cieInfo);
1681 foundInCache = foundFDE;
1682 }
1683 }
1684 if (!foundFDE) {
1685 // Still not found, do full scan of __eh_frame section.
1686 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1687 sects.dwarf_section_length, 0,
1688 &fdeInfo, &cieInfo);
1689 }
1690 if (foundFDE) {
1691 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) {
1692 // Add to cache (to make next lookup faster) if we had no hint
1693 // and there was no index.
1694 if (!foundInCache && (fdeSectionOffsetHint == 0)) {
1695 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1696 if (sects.dwarf_index_section == 0)
1697 #endif
1698 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
1699 fdeInfo.fdeStart);
1700 }
1701 return true;
1702 }
1703 }
1704 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
1705 return false;
1706 }
1707 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1708
1709
1710 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1711 template <typename A, typename R>
1712 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
1713 const UnwindInfoSections &sects) {
1714 const bool log = false;
1715 if (log)
1716 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
1717 (uint64_t)pc, (uint64_t)sects.dso_base);
1718
1719 const UnwindSectionHeader<A> sectionHeader(_addressSpace,
1720 sects.compact_unwind_section);
1721 if (sectionHeader.version() != UNWIND_SECTION_VERSION)
1722 return false;
1723
1724 // do a binary search of top level index to find page with unwind info
1725 pint_t targetFunctionOffset = pc - sects.dso_base;
1726 const UnwindSectionIndexArray<A> topIndex(_addressSpace,
1727 sects.compact_unwind_section
1728 + sectionHeader.indexSectionOffset());
1729 uint32_t low = 0;
1730 uint32_t high = sectionHeader.indexCount();
1731 uint32_t last = high - 1;
1732 while (low < high) {
1733 uint32_t mid = (low + high) / 2;
1734 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
1735 //mid, low, high, topIndex.functionOffset(mid));
1736 if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
1737 if ((mid == last) ||
1738 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
1739 low = mid;
1740 break;
1741 } else {
1742 low = mid + 1;
1743 }
1744 } else {
1745 high = mid;
1746 }
1747 }
1748 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
1749 const uint32_t firstLevelNextPageFunctionOffset =
1750 topIndex.functionOffset(low + 1);
1751 const pint_t secondLevelAddr =
1752 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
1753 const pint_t lsdaArrayStartAddr =
1754 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
1755 const pint_t lsdaArrayEndAddr =
1756 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
1757 if (log)
1758 fprintf(stderr, "\tfirst level search for result index=%d "
1759 "to secondLevelAddr=0x%llX\n",
1760 low, (uint64_t) secondLevelAddr);
1761 // do a binary search of second level page index
1762 uint32_t encoding = 0;
1763 pint_t funcStart = 0;
1764 pint_t funcEnd = 0;
1765 pint_t lsda = 0;
1766 pint_t personality = 0;
1767 uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
1768 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
1769 // regular page
1770 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
1771 secondLevelAddr);
1772 UnwindSectionRegularArray<A> pageIndex(
1773 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1774 // binary search looks for entry with e where index[e].offset <= pc <
1775 // index[e+1].offset
1776 if (log)
1777 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
1778 "regular page starting at secondLevelAddr=0x%llX\n",
1779 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
1780 low = 0;
1781 high = pageHeader.entryCount();
1782 while (low < high) {
1783 uint32_t mid = (low + high) / 2;
1784 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
1785 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
1786 // at end of table
1787 low = mid;
1788 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1789 break;
1790 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
1791 // next is too big, so we found it
1792 low = mid;
1793 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
1794 break;
1795 } else {
1796 low = mid + 1;
1797 }
1798 } else {
1799 high = mid;
1800 }
1801 }
1802 encoding = pageIndex.encoding(low);
1803 funcStart = pageIndex.functionOffset(low) + sects.dso_base;
1804 if (pc < funcStart) {
1805 if (log)
1806 fprintf(
1807 stderr,
1808 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1809 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1810 return false;
1811 }
1812 if (pc > funcEnd) {
1813 if (log)
1814 fprintf(
1815 stderr,
1816 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1817 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1818 return false;
1819 }
1820 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
1821 // compressed page
1822 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
1823 secondLevelAddr);
1824 UnwindSectionCompressedArray<A> pageIndex(
1825 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1826 const uint32_t targetFunctionPageOffset =
1827 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
1828 // binary search looks for entry with e where index[e].offset <= pc <
1829 // index[e+1].offset
1830 if (log)
1831 fprintf(stderr, "\tbinary search of compressed page starting at "
1832 "secondLevelAddr=0x%llX\n",
1833 (uint64_t) secondLevelAddr);
1834 low = 0;
1835 last = pageHeader.entryCount() - 1;
1836 high = pageHeader.entryCount();
1837 while (low < high) {
1838 uint32_t mid = (low + high) / 2;
1839 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
1840 if ((mid == last) ||
1841 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
1842 low = mid;
1843 break;
1844 } else {
1845 low = mid + 1;
1846 }
1847 } else {
1848 high = mid;
1849 }
1850 }
1851 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
1852 + sects.dso_base;
1853 if (low < last)
1854 funcEnd =
1855 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
1856 + sects.dso_base;
1857 else
1858 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1859 if (pc < funcStart) {
1860 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1861 "not in second level compressed unwind table. "
1862 "funcStart=0x%llX",
1863 (uint64_t) pc, (uint64_t) funcStart);
1864 return false;
1865 }
1866 if (pc > funcEnd) {
1867 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1868 "not in second level compressed unwind table. "
1869 "funcEnd=0x%llX",
1870 (uint64_t) pc, (uint64_t) funcEnd);
1871 return false;
1872 }
1873 uint16_t encodingIndex = pageIndex.encodingIndex(low);
1874 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
1875 // encoding is in common table in section header
1876 encoding = _addressSpace.get32(
1877 sects.compact_unwind_section +
1878 sectionHeader.commonEncodingsArraySectionOffset() +
1879 encodingIndex * sizeof(uint32_t));
1880 } else {
1881 // encoding is in page specific table
1882 uint16_t pageEncodingIndex =
1883 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
1884 encoding = _addressSpace.get32(secondLevelAddr +
1885 pageHeader.encodingsPageOffset() +
1886 pageEncodingIndex * sizeof(uint32_t));
1887 }
1888 } else {
1889 _LIBUNWIND_DEBUG_LOG(
1890 "malformed __unwind_info at 0x%0llX bad second level page",
1891 (uint64_t)sects.compact_unwind_section);
1892 return false;
1893 }
1894
1895 // look up LSDA, if encoding says function has one
1896 if (encoding & UNWIND_HAS_LSDA) {
1897 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
1898 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
1899 low = 0;
1900 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
1901 sizeof(unwind_info_section_header_lsda_index_entry);
1902 // binary search looks for entry with exact match for functionOffset
1903 if (log)
1904 fprintf(stderr,
1905 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
1906 funcStartOffset);
1907 while (low < high) {
1908 uint32_t mid = (low + high) / 2;
1909 if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
1910 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
1911 break;
1912 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
1913 low = mid + 1;
1914 } else {
1915 high = mid;
1916 }
1917 }
1918 if (lsda == 0) {
1919 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
1920 "pc=0x%0llX, but lsda table has no entry",
1921 encoding, (uint64_t) pc);
1922 return false;
1923 }
1924 }
1925
1926 // extract personality routine, if encoding says function has one
1927 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
1928 (__builtin_ctz(UNWIND_PERSONALITY_MASK));
1929 if (personalityIndex != 0) {
1930 --personalityIndex; // change 1-based to zero-based index
1931 if (personalityIndex >= sectionHeader.personalityArrayCount()) {
1932 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
1933 "but personality table has only %d entries",
1934 encoding, personalityIndex,
1935 sectionHeader.personalityArrayCount());
1936 return false;
1937 }
1938 int32_t personalityDelta = (int32_t)_addressSpace.get32(
1939 sects.compact_unwind_section +
1940 sectionHeader.personalityArraySectionOffset() +
1941 personalityIndex * sizeof(uint32_t));
1942 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
1943 personality = _addressSpace.getP(personalityPointer);
1944 if (log)
1945 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1946 "personalityDelta=0x%08X, personality=0x%08llX\n",
1947 (uint64_t) pc, personalityDelta, (uint64_t) personality);
1948 }
1949
1950 if (log)
1951 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1952 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
1953 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
1954 _info.start_ip = funcStart;
1955 _info.end_ip = funcEnd;
1956 _info.lsda = lsda;
1957 _info.handler = personality;
1958 _info.gp = 0;
1959 _info.flags = 0;
1960 _info.format = encoding;
1961 _info.unwind_info = 0;
1962 _info.unwind_info_size = 0;
1963 _info.extra = sects.dso_base;
1964 return true;
1965 }
1966 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1967
1968
1969 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1970 template <typename A, typename R>
1971 bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
1972 pint_t base;
1973 RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
1974 if (!unwindEntry) {
1975 _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
1976 return false;
1977 }
1978 _info.gp = 0;
1979 _info.flags = 0;
1980 _info.format = 0;
1981 _info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
1982 _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
1983 _info.extra = base;
1984 _info.start_ip = base + unwindEntry->BeginAddress;
1985 #ifdef _LIBUNWIND_TARGET_X86_64
1986 _info.end_ip = base + unwindEntry->EndAddress;
1987 // Only fill in the handler and LSDA if they're stale.
1988 if (pc != getLastPC()) {
1989 UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
1990 if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
1991 // The personality is given in the UNWIND_INFO itself. The LSDA immediately
1992 // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
1993 // these structures.)
1994 // N.B. UNWIND_INFO structs are DWORD-aligned.
1995 uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
1996 const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
1997 _info.lsda = reinterpret_cast<unw_word_t>(handler+1);
1998 _dispContext.HandlerData = reinterpret_cast<void *>(_info.lsda);
1999 _dispContext.LanguageHandler =
2000 reinterpret_cast<EXCEPTION_ROUTINE *>(base + *handler);
2001 if (*handler) {
2002 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2003 } else
2004 _info.handler = 0;
2005 } else {
2006 _info.lsda = 0;
2007 _info.handler = 0;
2008 }
2009 }
2010 #endif
2011 setLastPC(pc);
2012 return true;
2013 }
2014 #endif
2015
2016 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2017 // Masks for traceback table field xtbtable.
2018 enum xTBTableMask : uint8_t {
2019 reservedBit = 0x02, // The traceback table was incorrectly generated if set
2020 // (see comments in function getInfoFromTBTable().
2021 ehInfoBit = 0x08 // Exception handling info is present if set
2022 };
2023
2024 enum frameType : unw_word_t {
2025 frameWithXLEHStateTable = 0,
2026 frameWithEHInfo = 1
2027 };
2028
2029 extern "C" {
2030 typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
2031 uint64_t,
2032 _Unwind_Exception *,
2033 struct _Unwind_Context *);
2034 __attribute__((__weak__)) __xlcxx_personality_v0_t __xlcxx_personality_v0;
2035 }
2036
2037 static __xlcxx_personality_v0_t *xlcPersonalityV0;
2038 static RWMutex xlcPersonalityV0InitLock;
2039
2040 template <typename A, typename R>
2041 bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R &registers) {
2042 uint32_t *p = reinterpret_cast<uint32_t *>(pc);
2043
2044 // Keep looking forward until a word of 0 is found. The traceback
2045 // table starts at the following word.
2046 while (*p)
2047 ++p;
2048 tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
2049
2050 if (_LIBUNWIND_TRACING_UNWINDING) {
2051 char functionBuf[512];
2052 const char *functionName = functionBuf;
2053 unw_word_t offset;
2054 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2055 functionName = ".anonymous.";
2056 }
2057 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2058 __func__, functionName,
2059 reinterpret_cast<void *>(TBTable));
2060 }
2061
2062 // If the traceback table does not contain necessary info, bypass this frame.
2063 if (!TBTable->tb.has_tboff)
2064 return false;
2065
2066 // Structure tbtable_ext contains important data we are looking for.
2067 p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2068
2069 // Skip field parminfo if it exists.
2070 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2071 ++p;
2072
2073 // p now points to tb_offset, the offset from start of function to TB table.
2074 unw_word_t start_ip =
2075 reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
2076 unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
2077 ++p;
2078
2079 _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
2080 reinterpret_cast<void *>(start_ip),
2081 reinterpret_cast<void *>(end_ip));
2082
2083 // Skip field hand_mask if it exists.
2084 if (TBTable->tb.int_hndl)
2085 ++p;
2086
2087 unw_word_t lsda = 0;
2088 unw_word_t handler = 0;
2089 unw_word_t flags = frameType::frameWithXLEHStateTable;
2090
2091 if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
2092 // State table info is available. The ctl_info field indicates the
2093 // number of CTL anchors. There should be only one entry for the C++
2094 // state table.
2095 assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
2096 ++p;
2097 // p points to the offset of the state table into the stack.
2098 pint_t stateTableOffset = *p++;
2099
2100 int framePointerReg;
2101
2102 // Skip fields name_len and name if exist.
2103 if (TBTable->tb.name_present) {
2104 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
2105 p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
2106 sizeof(uint16_t));
2107 }
2108
2109 if (TBTable->tb.uses_alloca)
2110 framePointerReg = *(reinterpret_cast<char *>(p));
2111 else
2112 framePointerReg = 1; // default frame pointer == SP
2113
2114 _LIBUNWIND_TRACE_UNWINDING(
2115 "framePointerReg=%d, framePointer=%p, "
2116 "stateTableOffset=%#lx\n",
2117 framePointerReg,
2118 reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
2119 stateTableOffset);
2120 lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
2121
2122 // Since the traceback table generated by the legacy XLC++ does not
2123 // provide the location of the personality for the state table,
2124 // function __xlcxx_personality_v0(), which is the personality for the state
2125 // table and is exported from libc++abi, is directly assigned as the
2126 // handler here. When a legacy XLC++ frame is encountered, the symbol
2127 // is resolved dynamically using dlopen() to avoid hard dependency from
2128 // libunwind on libc++abi.
2129
2130 // Resolve the function pointer to the state table personality if it has
2131 // not already.
2132 if (xlcPersonalityV0 == NULL) {
2133 xlcPersonalityV0InitLock.lock();
2134 if (xlcPersonalityV0 == NULL) {
2135 // If libc++abi is statically linked in, symbol __xlcxx_personality_v0
2136 // has been resolved at the link time.
2137 xlcPersonalityV0 = &__xlcxx_personality_v0;
2138 if (xlcPersonalityV0 == NULL) {
2139 // libc++abi is dynamically linked. Resolve __xlcxx_personality_v0
2140 // using dlopen().
2141 const char libcxxabi[] = "libc++abi.a(libc++abi.so.1)";
2142 void *libHandle;
2143 // The AIX dlopen() sets errno to 0 when it is successful, which
2144 // clobbers the value of errno from the user code. This is an AIX
2145 // bug because according to POSIX it should not set errno to 0. To
2146 // workaround before AIX fixes the bug, errno is saved and restored.
2147 int saveErrno = errno;
2148 libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
2149 if (libHandle == NULL) {
2150 _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n",
2151 errno);
2152 assert(0 && "dlopen() failed");
2153 }
2154 xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
2155 dlsym(libHandle, "__xlcxx_personality_v0"));
2156 if (xlcPersonalityV0 == NULL) {
2157 _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
2158 assert(0 && "dlsym() failed");
2159 }
2160 dlclose(libHandle);
2161 errno = saveErrno;
2162 }
2163 }
2164 xlcPersonalityV0InitLock.unlock();
2165 }
2166 handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
2167 _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
2168 reinterpret_cast<void *>(lsda),
2169 reinterpret_cast<void *>(handler));
2170 } else if (TBTable->tb.longtbtable) {
2171 // This frame has the traceback table extension. Possible cases are
2172 // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
2173 // is not EH aware; or, 3) a frame of other languages. We need to figure out
2174 // if the traceback table extension contains the 'eh_info' structure.
2175 //
2176 // We also need to deal with the complexity arising from some XL compiler
2177 // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
2178 // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
2179 // versa. For frames of code generated by those compilers, the 'longtbtable'
2180 // bit may be set but there isn't really a traceback table extension.
2181 //
2182 // In </usr/include/sys/debug.h>, there is the following definition of
2183 // 'struct tbtable_ext'. It is not really a structure but a dummy to
2184 // collect the description of optional parts of the traceback table.
2185 //
2186 // struct tbtable_ext {
2187 // ...
2188 // char alloca_reg; /* Register for alloca automatic storage */
2189 // struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
2190 // unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
2191 // };
2192 //
2193 // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
2194 // following 'alloca_reg' can be treated either as 'struct vec_ext' or
2195 // 'unsigned char xtbtable'. 'xtbtable' bits are defined in
2196 // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
2197 // unused and should not be set. 'struct vec_ext' is defined in
2198 // </usr/include/sys/debug.h> as follows:
2199 //
2200 // struct vec_ext {
2201 // unsigned vr_saved:6; /* Number of non-volatile vector regs saved
2202 // */
2203 // /* first register saved is assumed to be */
2204 // /* 32 - vr_saved */
2205 // unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */
2206 // unsigned has_varargs:1;
2207 // ...
2208 // };
2209 //
2210 // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
2211 // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
2212 // we checks if the 7th bit is set or not because 'xtbtable' should
2213 // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
2214 // in the future to make sure the mitigation works. This mitigation
2215 // is not 100% bullet proof because 'struct vec_ext' may not always have
2216 // 'saves_vrsave' bit set.
2217 //
2218 // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
2219 // checking the 7th bit.
2220
2221 // p points to field name len.
2222 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2223
2224 // Skip fields name_len and name if they exist.
2225 if (TBTable->tb.name_present) {
2226 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2227 charPtr = charPtr + name_len + sizeof(uint16_t);
2228 }
2229
2230 // Skip field alloc_reg if it exists.
2231 if (TBTable->tb.uses_alloca)
2232 ++charPtr;
2233
2234 // Check traceback table bit has_vec. Skip struct vec_ext if it exists.
2235 if (TBTable->tb.has_vec)
2236 // Note struct vec_ext does exist at this point because whether the
2237 // ordering of longtbtable and has_vec bits is correct or not, both
2238 // are set.
2239 charPtr += sizeof(struct vec_ext);
2240
2241 // charPtr points to field 'xtbtable'. Check if the EH info is available.
2242 // Also check if the reserved bit of the extended traceback table field
2243 // 'xtbtable' is set. If it is, the traceback table was incorrectly
2244 // generated by an XL compiler that uses the wrong ordering of 'longtbtable'
2245 // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
2246 // frame.
2247 if ((*charPtr & xTBTableMask::ehInfoBit) &&
2248 !(*charPtr & xTBTableMask::reservedBit)) {
2249 // Mark this frame has the new EH info.
2250 flags = frameType::frameWithEHInfo;
2251
2252 // eh_info is available.
2253 charPtr++;
2254 // The pointer is 4-byte aligned.
2255 if (reinterpret_cast<uintptr_t>(charPtr) % 4)
2256 charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
2257 uintptr_t *ehInfo =
2258 reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
2259 registers.getRegister(2) +
2260 *(reinterpret_cast<uintptr_t *>(charPtr)))));
2261
2262 // ehInfo points to structure en_info. The first member is version.
2263 // Only version 0 is currently supported.
2264 assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
2265 "libunwind: ehInfo version other than 0 is not supported");
2266
2267 // Increment ehInfo to point to member lsda.
2268 ++ehInfo;
2269 lsda = *ehInfo++;
2270
2271 // enInfo now points to member personality.
2272 handler = *ehInfo;
2273
2274 _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
2275 lsda, handler);
2276 }
2277 }
2278
2279 _info.start_ip = start_ip;
2280 _info.end_ip = end_ip;
2281 _info.lsda = lsda;
2282 _info.handler = handler;
2283 _info.gp = 0;
2284 _info.flags = flags;
2285 _info.format = 0;
2286 _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
2287 _info.unwind_info_size = 0;
2288 _info.extra = registers.getRegister(2);
2289
2290 return true;
2291 }
2292
2293 // Step back up the stack following the frame back link.
2294 template <typename A, typename R>
2295 int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
2296 R &registers, bool &isSignalFrame) {
2297 if (_LIBUNWIND_TRACING_UNWINDING) {
2298 char functionBuf[512];
2299 const char *functionName = functionBuf;
2300 unw_word_t offset;
2301 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2302 functionName = ".anonymous.";
2303 }
2304 _LIBUNWIND_TRACE_UNWINDING(
2305 "%s: Look up traceback table of func=%s at %p, pc=%p, "
2306 "SP=%p, saves_lr=%d, stores_bc=%d",
2307 __func__, functionName, reinterpret_cast<void *>(TBTable),
2308 reinterpret_cast<void *>(pc),
2309 reinterpret_cast<void *>(registers.getSP()), TBTable->tb.saves_lr,
2310 TBTable->tb.stores_bc);
2311 }
2312
2313 #if defined(__powerpc64__)
2314 // Instruction to reload TOC register "ld r2,40(r1)"
2315 const uint32_t loadTOCRegInst = 0xe8410028;
2316 const int32_t unwPPCF0Index = UNW_PPC64_F0;
2317 const int32_t unwPPCV0Index = UNW_PPC64_V0;
2318 #else
2319 // Instruction to reload TOC register "lwz r2,20(r1)"
2320 const uint32_t loadTOCRegInst = 0x80410014;
2321 const int32_t unwPPCF0Index = UNW_PPC_F0;
2322 const int32_t unwPPCV0Index = UNW_PPC_V0;
2323 #endif
2324
2325 // lastStack points to the stack frame of the next routine up.
2326 pint_t curStack = static_cast<pint_t>(registers.getSP());
2327 pint_t lastStack = *reinterpret_cast<pint_t *>(curStack);
2328
2329 if (lastStack == 0)
2330 return UNW_STEP_END;
2331
2332 R newRegisters = registers;
2333
2334 // If backchain is not stored, use the current stack frame.
2335 if (!TBTable->tb.stores_bc)
2336 lastStack = curStack;
2337
2338 // Return address is the address after call site instruction.
2339 pint_t returnAddress;
2340
2341 if (isSignalFrame) {
2342 _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
2343 reinterpret_cast<void *>(lastStack));
2344
2345 sigcontext *sigContext = reinterpret_cast<sigcontext *>(
2346 reinterpret_cast<char *>(lastStack) + STKMINALIGN);
2347 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2348
2349 bool useSTKMIN = false;
2350 if (returnAddress < 0x10000000) {
2351 // Try again using STKMIN.
2352 sigContext = reinterpret_cast<sigcontext *>(
2353 reinterpret_cast<char *>(lastStack) + STKMIN);
2354 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2355 if (returnAddress < 0x10000000) {
2356 _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p from sigcontext=%p",
2357 reinterpret_cast<void *>(returnAddress),
2358 reinterpret_cast<void *>(sigContext));
2359 return UNW_EBADFRAME;
2360 }
2361 useSTKMIN = true;
2362 }
2363 _LIBUNWIND_TRACE_UNWINDING("Returning from a signal handler %s: "
2364 "sigContext=%p, returnAddress=%p. "
2365 "Seems to be a valid address",
2366 useSTKMIN ? "STKMIN" : "STKMINALIGN",
2367 reinterpret_cast<void *>(sigContext),
2368 reinterpret_cast<void *>(returnAddress));
2369
2370 // Restore the condition register from sigcontext.
2371 newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
2372
2373 // Save the LR in sigcontext for stepping up when the function that
2374 // raised the signal is a leaf function. This LR has the return address
2375 // to the caller of the leaf function.
2376 newRegisters.setLR(sigContext->sc_jmpbuf.jmp_context.lr);
2377 _LIBUNWIND_TRACE_UNWINDING(
2378 "Save LR=%p from sigcontext",
2379 reinterpret_cast<void *>(sigContext->sc_jmpbuf.jmp_context.lr));
2380
2381 // Restore GPRs from sigcontext.
2382 for (int i = 0; i < 32; ++i)
2383 newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
2384
2385 // Restore FPRs from sigcontext.
2386 for (int i = 0; i < 32; ++i)
2387 newRegisters.setFloatRegister(i + unwPPCF0Index,
2388 sigContext->sc_jmpbuf.jmp_context.fpr[i]);
2389
2390 // Restore vector registers if there is an associated extended context
2391 // structure.
2392 if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
2393 ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
2394 if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
2395 for (int i = 0; i < 32; ++i)
2396 newRegisters.setVectorRegister(
2397 i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
2398 &(uContext->__extctx->__vmx.__vr[i]))));
2399 }
2400 }
2401 } else {
2402 // Step up a normal frame.
2403
2404 if (!TBTable->tb.saves_lr && registers.getLR()) {
2405 // This case should only occur if we were called from a signal handler
2406 // and the signal occurred in a function that doesn't save the LR.
2407 returnAddress = static_cast<pint_t>(registers.getLR());
2408 _LIBUNWIND_TRACE_UNWINDING("Use saved LR=%p",
2409 reinterpret_cast<void *>(returnAddress));
2410 } else {
2411 // Otherwise, use the LR value in the stack link area.
2412 returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
2413 }
2414
2415 // Reset LR in the current context.
2416 newRegisters.setLR(NULL);
2417
2418 _LIBUNWIND_TRACE_UNWINDING(
2419 "Extract info from lastStack=%p, returnAddress=%p",
2420 reinterpret_cast<void *>(lastStack),
2421 reinterpret_cast<void *>(returnAddress));
2422 _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d",
2423 TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
2424 TBTable->tb.saves_cr);
2425
2426 // Restore FP registers.
2427 char *ptrToRegs = reinterpret_cast<char *>(lastStack);
2428 double *FPRegs = reinterpret_cast<double *>(
2429 ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
2430 for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
2431 newRegisters.setFloatRegister(
2432 32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
2433
2434 // Restore GP registers.
2435 ptrToRegs = reinterpret_cast<char *>(FPRegs);
2436 uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
2437 ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
2438 for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
2439 newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
2440
2441 // Restore Vector registers.
2442 ptrToRegs = reinterpret_cast<char *>(GPRegs);
2443
2444 // Restore vector registers only if this is a Clang frame. Also
2445 // check if traceback table bit has_vec is set. If it is, structure
2446 // vec_ext is available.
2447 if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
2448
2449 // Get to the vec_ext structure to check if vector registers are saved.
2450 uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2451
2452 // Skip field parminfo if exists.
2453 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2454 ++p;
2455
2456 // Skip field tb_offset if exists.
2457 if (TBTable->tb.has_tboff)
2458 ++p;
2459
2460 // Skip field hand_mask if exists.
2461 if (TBTable->tb.int_hndl)
2462 ++p;
2463
2464 // Skip fields ctl_info and ctl_info_disp if exist.
2465 if (TBTable->tb.has_ctl) {
2466 // Skip field ctl_info.
2467 ++p;
2468 // Skip field ctl_info_disp.
2469 ++p;
2470 }
2471
2472 // Skip fields name_len and name if exist.
2473 // p is supposed to point to field name_len now.
2474 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2475 if (TBTable->tb.name_present) {
2476 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2477 charPtr = charPtr + name_len + sizeof(uint16_t);
2478 }
2479
2480 // Skip field alloc_reg if it exists.
2481 if (TBTable->tb.uses_alloca)
2482 ++charPtr;
2483
2484 struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
2485
2486 _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d", vec_ext->vr_saved);
2487
2488 // Restore vector register(s) if saved on the stack.
2489 if (vec_ext->vr_saved) {
2490 // Saved vector registers are 16-byte aligned.
2491 if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
2492 ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
2493 v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
2494 sizeof(v128));
2495 for (int i = 0; i < vec_ext->vr_saved; ++i) {
2496 newRegisters.setVectorRegister(
2497 32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
2498 }
2499 }
2500 }
2501 if (TBTable->tb.saves_cr) {
2502 // Get the saved condition register. The condition register is only
2503 // a single word.
2504 newRegisters.setCR(
2505 *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
2506 }
2507
2508 // Restore the SP.
2509 newRegisters.setSP(lastStack);
2510
2511 // The first instruction after return.
2512 uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
2513
2514 // Do we need to set the TOC register?
2515 _LIBUNWIND_TRACE_UNWINDING(
2516 "Current gpr2=%p",
2517 reinterpret_cast<void *>(newRegisters.getRegister(2)));
2518 if (firstInstruction == loadTOCRegInst) {
2519 _LIBUNWIND_TRACE_UNWINDING(
2520 "Set gpr2=%p from frame",
2521 reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
2522 newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
2523 }
2524 }
2525 _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
2526 reinterpret_cast<void *>(lastStack),
2527 reinterpret_cast<void *>(returnAddress),
2528 reinterpret_cast<void *>(pc));
2529
2530 // The return address is the address after call site instruction, so
2531 // setting IP to that simulates a return.
2532 newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
2533
2534 // Simulate the step by replacing the register set with the new ones.
2535 registers = newRegisters;
2536
2537 // Check if the next frame is a signal frame.
2538 pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2539
2540 // Return address is the address after call site instruction.
2541 pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
2542
2543 if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
2544 _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
2545 "nextStack=%p, next return address=%p\n",
2546 reinterpret_cast<void *>(nextStack),
2547 reinterpret_cast<void *>(nextReturnAddress));
2548 isSignalFrame = true;
2549 } else {
2550 isSignalFrame = false;
2551 }
2552 return UNW_STEP_SUCCESS;
2553 }
2554 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2555
2556 template <typename A, typename R>
2557 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
2558 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2559 _isSigReturn = false;
2560 #endif
2561
2562 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2563 #if defined(_LIBUNWIND_ARM_EHABI)
2564 // Remove the thumb bit so the IP represents the actual instruction address.
2565 // This matches the behaviour of _Unwind_GetIP on arm.
2566 pc &= (pint_t)~0x1;
2567 #endif
2568
2569 // Exit early if at the top of the stack.
2570 if (pc == 0) {
2571 _unwindInfoMissing = true;
2572 return;
2573 }
2574
2575 // If the last line of a function is a "throw" the compiler sometimes
2576 // emits no instructions after the call to __cxa_throw. This means
2577 // the return address is actually the start of the next function.
2578 // To disambiguate this, back up the pc when we know it is a return
2579 // address.
2580 if (isReturnAddress)
2581 #if defined(_AIX)
2582 // PC needs to be a 4-byte aligned address to be able to look for a
2583 // word of 0 that indicates the start of the traceback table at the end
2584 // of a function on AIX.
2585 pc -= 4;
2586 #else
2587 --pc;
2588 #endif
2589
2590 // Ask address space object to find unwind sections for this pc.
2591 UnwindInfoSections sects;
2592 if (_addressSpace.findUnwindSections(pc, sects)) {
2593 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2594 // If there is a compact unwind encoding table, look there first.
2595 if (sects.compact_unwind_section != 0) {
2596 if (this->getInfoFromCompactEncodingSection(pc, sects)) {
2597 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2598 // Found info in table, done unless encoding says to use dwarf.
2599 uint32_t dwarfOffset;
2600 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
2601 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
2602 // found info in dwarf, done
2603 return;
2604 }
2605 }
2606 #endif
2607 // If unwind table has entry, but entry says there is no unwind info,
2608 // record that we have no unwind info.
2609 if (_info.format == 0)
2610 _unwindInfoMissing = true;
2611 return;
2612 }
2613 }
2614 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2615
2616 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2617 // If there is SEH unwind info, look there next.
2618 if (this->getInfoFromSEH(pc))
2619 return;
2620 #endif
2621
2622 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2623 // If there is unwind info in the traceback table, look there next.
2624 if (this->getInfoFromTBTable(pc, _registers))
2625 return;
2626 #endif
2627
2628 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2629 // If there is dwarf unwind info, look there next.
2630 if (sects.dwarf_section != 0) {
2631 if (this->getInfoFromDwarfSection(pc, sects)) {
2632 // found info in dwarf, done
2633 return;
2634 }
2635 }
2636 #endif
2637
2638 #if defined(_LIBUNWIND_ARM_EHABI)
2639 // If there is ARM EHABI unwind info, look there next.
2640 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
2641 return;
2642 #endif
2643 }
2644
2645 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2646 // There is no static unwind info for this pc. Look to see if an FDE was
2647 // dynamically registered for it.
2648 pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
2649 pc);
2650 if (cachedFDE != 0) {
2651 typename CFI_Parser<A>::FDE_Info fdeInfo;
2652 typename CFI_Parser<A>::CIE_Info cieInfo;
2653 if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
2654 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2655 return;
2656 }
2657
2658 // Lastly, ask AddressSpace object about platform specific ways to locate
2659 // other FDEs.
2660 pint_t fde;
2661 if (_addressSpace.findOtherFDE(pc, fde)) {
2662 typename CFI_Parser<A>::FDE_Info fdeInfo;
2663 typename CFI_Parser<A>::CIE_Info cieInfo;
2664 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
2665 // Double check this FDE is for a function that includes the pc.
2666 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
2667 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2668 return;
2669 }
2670 }
2671 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2672
2673 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2674 if (setInfoForSigReturn())
2675 return;
2676 #endif
2677
2678 // no unwind info, flag that we can't reliably unwind
2679 _unwindInfoMissing = true;
2680 }
2681
2682 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2683 defined(_LIBUNWIND_TARGET_AARCH64)
2684 template <typename A, typename R>
2685 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
2686 // Look for the sigreturn trampoline. The trampoline's body is two
2687 // specific instructions (see below). Typically the trampoline comes from the
2688 // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
2689 // own restorer function, though, or user-mode QEMU might write a trampoline
2690 // onto the stack.
2691 //
2692 // This special code path is a fallback that is only used if the trampoline
2693 // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
2694 // constant for the PC needs to be defined before DWARF can handle a signal
2695 // trampoline. This code may segfault if the target PC is unreadable, e.g.:
2696 // - The PC points at a function compiled without unwind info, and which is
2697 // part of an execute-only mapping (e.g. using -Wl,--execute-only).
2698 // - The PC is invalid and happens to point to unreadable or unmapped memory.
2699 //
2700 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
2701 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2702 // The PC might contain an invalid address if the unwind info is bad, so
2703 // directly accessing it could cause a segfault. Use process_vm_readv to read
2704 // the memory safely instead. process_vm_readv was added in Linux 3.2, and
2705 // AArch64 supported was added in Linux 3.7, so the syscall is guaranteed to
2706 // be present. Unfortunately, there are Linux AArch64 environments where the
2707 // libc wrapper for the syscall might not be present (e.g. Android 5), so call
2708 // the syscall directly instead.
2709 uint32_t instructions[2];
2710 struct iovec local_iov = {&instructions, sizeof instructions};
2711 struct iovec remote_iov = {reinterpret_cast<void *>(pc), sizeof instructions};
2712 long bytesRead =
2713 syscall(SYS_process_vm_readv, getpid(), &local_iov, 1, &remote_iov, 1, 0);
2714 // Look for instructions: mov x8, #0x8b; svc #0x0
2715 if (bytesRead != sizeof instructions || instructions[0] != 0xd2801168 ||
2716 instructions[1] != 0xd4000001)
2717 return false;
2718
2719 _info = {};
2720 _info.start_ip = pc;
2721 _info.end_ip = pc + 4;
2722 _isSigReturn = true;
2723 return true;
2724 }
2725
2726 template <typename A, typename R>
2727 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
2728 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2729 // - 128-byte siginfo struct
2730 // - ucontext struct:
2731 // - 8-byte long (uc_flags)
2732 // - 8-byte pointer (uc_link)
2733 // - 24-byte stack_t
2734 // - 128-byte signal set
2735 // - 8 bytes of padding because sigcontext has 16-byte alignment
2736 // - sigcontext/mcontext_t
2737 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
2738 const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
2739
2740 // Offsets from sigcontext to each register.
2741 const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
2742 const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
2743 const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
2744
2745 pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2746
2747 for (int i = 0; i <= 30; ++i) {
2748 uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
2749 static_cast<pint_t>(i * 8));
2750 _registers.setRegister(UNW_AARCH64_X0 + i, value);
2751 }
2752 _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
2753 _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
2754 _isSignalFrame = true;
2755 return UNW_STEP_SUCCESS;
2756 }
2757 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2758 // defined(_LIBUNWIND_TARGET_AARCH64)
2759
2760 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2761 defined(_LIBUNWIND_TARGET_RISCV)
2762 template <typename A, typename R>
2763 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_riscv &) {
2764 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2765 uint32_t instructions[2];
2766 struct iovec local_iov = {&instructions, sizeof instructions};
2767 struct iovec remote_iov = {reinterpret_cast<void *>(pc), sizeof instructions};
2768 long bytesRead =
2769 syscall(SYS_process_vm_readv, getpid(), &local_iov, 1, &remote_iov, 1, 0);
2770 // Look for the two instructions used in the sigreturn trampoline
2771 // __vdso_rt_sigreturn:
2772 //
2773 // 0x08b00893 li a7,0x8b
2774 // 0x00000073 ecall
2775 if (bytesRead != sizeof instructions || instructions[0] != 0x08b00893 ||
2776 instructions[1] != 0x00000073)
2777 return false;
2778
2779 _info = {};
2780 _info.start_ip = pc;
2781 _info.end_ip = pc + 4;
2782 _isSigReturn = true;
2783 return true;
2784 }
2785
2786 template <typename A, typename R>
2787 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_riscv &) {
2788 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2789 // - 128-byte siginfo struct
2790 // - ucontext_t struct:
2791 // - 8-byte long (__uc_flags)
2792 // - 8-byte pointer (*uc_link)
2793 // - 24-byte uc_stack
2794 // - 8-byte uc_sigmask
2795 // - 120-byte of padding to allow sigset_t to be expanded in the future
2796 // - 8 bytes of padding because sigcontext has 16-byte alignment
2797 // - struct sigcontext uc_mcontext
2798 // [1]
2799 // https://github.com/torvalds/linux/blob/master/arch/riscv/kernel/signal.c
2800 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2801
2802 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2803 _registers.setIP(_addressSpace.get64(sigctx));
2804 for (int i = UNW_RISCV_X1; i <= UNW_RISCV_X31; ++i) {
2805 uint64_t value = _addressSpace.get64(sigctx + static_cast<pint_t>(i * 8));
2806 _registers.setRegister(i, value);
2807 }
2808 _isSignalFrame = true;
2809 return UNW_STEP_SUCCESS;
2810 }
2811 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2812 // defined(_LIBUNWIND_TARGET_RISCV)
2813
2814 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2815 defined(_LIBUNWIND_TARGET_S390X)
2816 template <typename A, typename R>
2817 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
2818 // Look for the sigreturn trampoline. The trampoline's body is a
2819 // specific instruction (see below). Typically the trampoline comes from the
2820 // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its
2821 // own restorer function, though, or user-mode QEMU might write a trampoline
2822 // onto the stack.
2823 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2824 // The PC might contain an invalid address if the unwind info is bad, so
2825 // directly accessing it could cause a segfault. Use process_vm_readv to
2826 // read the memory safely instead.
2827 uint16_t inst;
2828 struct iovec local_iov = {&inst, sizeof inst};
2829 struct iovec remote_iov = {reinterpret_cast<void *>(pc), sizeof inst};
2830 long bytesRead = process_vm_readv(getpid(), &local_iov, 1, &remote_iov, 1, 0);
2831 if (bytesRead == sizeof inst && (inst == 0x0a77 || inst == 0x0aad)) {
2832 _info = {};
2833 _info.start_ip = pc;
2834 _info.end_ip = pc + 2;
2835 _isSigReturn = true;
2836 return true;
2837 }
2838 return false;
2839 }
2840
2841 template <typename A, typename R>
2842 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
2843 // Determine current SP.
2844 const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP));
2845 // According to the s390x ABI, the CFA is at (incoming) SP + 160.
2846 const pint_t cfa = sp + 160;
2847
2848 // Determine current PC and instruction there (this must be either
2849 // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn").
2850 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2851 const uint16_t inst = _addressSpace.get16(pc);
2852
2853 // Find the addresses of the signo and sigcontext in the frame.
2854 pint_t pSigctx = 0;
2855 pint_t pSigno = 0;
2856
2857 // "svc __NR_sigreturn" uses a non-RT signal trampoline frame.
2858 if (inst == 0x0a77) {
2859 // Layout of a non-RT signal trampoline frame, starting at the CFA:
2860 // - 8-byte signal mask
2861 // - 8-byte pointer to sigcontext, followed by signo
2862 // - 4-byte signo
2863 pSigctx = _addressSpace.get64(cfa + 8);
2864 pSigno = pSigctx + 344;
2865 }
2866
2867 // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame.
2868 if (inst == 0x0aad) {
2869 // Layout of a RT signal trampoline frame, starting at the CFA:
2870 // - 8-byte retcode (+ alignment)
2871 // - 128-byte siginfo struct (starts with signo)
2872 // - ucontext struct:
2873 // - 8-byte long (uc_flags)
2874 // - 8-byte pointer (uc_link)
2875 // - 24-byte stack_t
2876 // - 8 bytes of padding because sigcontext has 16-byte alignment
2877 // - sigcontext/mcontext_t
2878 pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8;
2879 pSigno = cfa + 8;
2880 }
2881
2882 assert(pSigctx != 0);
2883 assert(pSigno != 0);
2884
2885 // Offsets from sigcontext to each register.
2886 const pint_t kOffsetPc = 8;
2887 const pint_t kOffsetGprs = 16;
2888 const pint_t kOffsetFprs = 216;
2889
2890 // Restore all registers.
2891 for (int i = 0; i < 16; ++i) {
2892 uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs +
2893 static_cast<pint_t>(i * 8));
2894 _registers.setRegister(UNW_S390X_R0 + i, value);
2895 }
2896 for (int i = 0; i < 16; ++i) {
2897 static const int fpr[16] = {
2898 UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3,
2899 UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7,
2900 UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11,
2901 UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15
2902 };
2903 double value = _addressSpace.getDouble(pSigctx + kOffsetFprs +
2904 static_cast<pint_t>(i * 8));
2905 _registers.setFloatRegister(fpr[i], value);
2906 }
2907 _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc));
2908
2909 // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
2910 // after the faulting instruction rather than before it.
2911 // Do not set _isSignalFrame in that case.
2912 uint32_t signo = _addressSpace.get32(pSigno);
2913 _isSignalFrame = (signo != 4 && signo != 5 && signo != 8);
2914
2915 return UNW_STEP_SUCCESS;
2916 }
2917 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2918 // defined(_LIBUNWIND_TARGET_S390X)
2919
2920 template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
2921 (void)stage2;
2922 // Bottom of stack is defined is when unwind info cannot be found.
2923 if (_unwindInfoMissing)
2924 return UNW_STEP_END;
2925
2926 // Use unwinding info to modify register set as if function returned.
2927 int result;
2928 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2929 if (_isSigReturn) {
2930 result = this->stepThroughSigReturn();
2931 } else
2932 #endif
2933 {
2934 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2935 result = this->stepWithCompactEncoding(stage2);
2936 #elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2937 result = this->stepWithSEHData();
2938 #elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2939 result = this->stepWithTBTableData();
2940 #elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2941 result = this->stepWithDwarfFDE(stage2);
2942 #elif defined(_LIBUNWIND_ARM_EHABI)
2943 result = this->stepWithEHABI();
2944 #else
2945 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
2946 _LIBUNWIND_SUPPORT_SEH_UNWIND or \
2947 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
2948 _LIBUNWIND_ARM_EHABI
2949 #endif
2950 }
2951
2952 // update info based on new PC
2953 if (result == UNW_STEP_SUCCESS) {
2954 this->setInfoBasedOnIPRegister(true);
2955 if (_unwindInfoMissing)
2956 return UNW_STEP_END;
2957 }
2958
2959 return result;
2960 }
2961
2962 template <typename A, typename R>
2963 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
2964 if (_unwindInfoMissing)
2965 memset(info, 0, sizeof(*info));
2966 else
2967 *info = _info;
2968 }
2969
2970 template <typename A, typename R>
2971 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
2972 unw_word_t *offset) {
2973 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
2974 buf, bufLen, offset);
2975 }
2976
2977 #if defined(_LIBUNWIND_USE_CET)
2978 extern "C" void *__libunwind_cet_get_registers(unw_cursor_t *cursor) {
2979 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
2980 return co->get_registers();
2981 }
2982 #endif
2983 } // namespace libunwind
2984
2985 #endif // __UNWINDCURSOR_HPP__
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