1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//
8// C++ interface to lower levels of libunwind
9//===----------------------------------------------------------------------===//
10
11#ifndef __UNWINDCURSOR_HPP__
12#define __UNWINDCURSOR_HPP__
13
14#include "shadow_stack_unwind.h"
15#include <stdint.h>
16#include <stdio.h>
17#include <stdlib.h>
18#include <unwind.h>
19
20#ifdef _WIN32
21 #include <windows.h>
22 #include <ntverp.h>
23#endif
24#ifdef __APPLE__
25 #include <mach-o/dyld.h>
26#endif
27#ifdef _AIX
28#include <dlfcn.h>
29#include <sys/debug.h>
30#include <sys/pseg.h>
31#endif
32
33#if defined(_LIBUNWIND_TARGET_LINUX) && \
34 (defined(_LIBUNWIND_TARGET_AARCH64) || \
35 defined(_LIBUNWIND_TARGET_LOONGARCH) || \
36 defined(_LIBUNWIND_TARGET_RISCV) || defined(_LIBUNWIND_TARGET_S390X))
37#include <errno.h>
38#include <signal.h>
39#include <sys/syscall.h>
40#include <unistd.h>
41#define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
42#endif
43
44#if defined(_LIBUNWIND_TARGET_HAIKU) && defined(_LIBUNWIND_TARGET_X86_64)
45#include <OS.h>
46#include <signal.h>
47#define _LIBUNWIND_CHECK_HAIKU_SIGRETURN 1
48#endif
49
50#include "AddressSpace.hpp"
51#include "CompactUnwinder.hpp"
52#include "config.h"
53#include "DwarfInstructions.hpp"
54#include "EHHeaderParser.hpp"
55#include "libunwind.h"
56#include "libunwind_ext.h"
57#include "Registers.hpp"
58#include "RWMutex.hpp"
59#include "Unwind-EHABI.h"
60
61#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
62// Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
63// earlier) SDKs.
64// MinGW-w64 has always provided this struct.
65 #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
66 !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
67struct _DISPATCHER_CONTEXT {
68 ULONG64 ControlPc;
69 ULONG64 ImageBase;
70 PRUNTIME_FUNCTION FunctionEntry;
71 ULONG64 EstablisherFrame;
72 ULONG64 TargetIp;
73 PCONTEXT ContextRecord;
74 PEXCEPTION_ROUTINE LanguageHandler;
75 PVOID HandlerData;
76 PUNWIND_HISTORY_TABLE HistoryTable;
77 ULONG ScopeIndex;
78 ULONG Fill0;
79};
80 #endif
81
82struct UNWIND_INFO {
83 uint8_t Version : 3;
84 uint8_t Flags : 5;
85 uint8_t SizeOfProlog;
86 uint8_t CountOfCodes;
87 uint8_t FrameRegister : 4;
88 uint8_t FrameOffset : 4;
89 uint16_t UnwindCodes[2];
90};
91
92#pragma clang diagnostic push
93#pragma clang diagnostic ignored "-Wgnu-anonymous-struct"
94union UNWIND_INFO_ARM {
95 DWORD HeaderData;
96 struct {
97 DWORD FunctionLength : 18;
98 DWORD Version : 2;
99 DWORD ExceptionDataPresent : 1;
100 DWORD EpilogInHeader : 1;
101 DWORD FunctionFragment : 1;
102 DWORD EpilogCount : 5;
103 DWORD CodeWords : 4;
104 };
105};
106#pragma clang diagnostic pop
107
108extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
109 int, _Unwind_Action, uint64_t, _Unwind_Exception *,
110 struct _Unwind_Context *);
111
112#endif
113
114namespace libunwind {
115
116#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
117/// Cache of recently found FDEs.
118template <typename A>
119class _LIBUNWIND_HIDDEN DwarfFDECache {
120 typedef typename A::pint_t pint_t;
121public:
122 static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
123 static pint_t findFDE(pint_t mh, pint_t pc);
124 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
125 static void removeAllIn(pint_t mh);
126 static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
127 unw_word_t ip_end,
128 unw_word_t fde, unw_word_t mh));
129
130private:
131
132 struct entry {
133 pint_t mh;
134 pint_t ip_start;
135 pint_t ip_end;
136 pint_t fde;
137 };
138
139 // These fields are all static to avoid needing an initializer.
140 // There is only one instance of this class per process.
141 static RWMutex _lock;
142#ifdef __APPLE__
143 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
144 static bool _registeredForDyldUnloads;
145#endif
146 static entry *_buffer;
147 static entry *_bufferUsed;
148 static entry *_bufferEnd;
149 static entry _initialBuffer[64];
150};
151
152template <typename A>
153typename DwarfFDECache<A>::entry *
154DwarfFDECache<A>::_buffer = _initialBuffer;
155
156template <typename A>
157typename DwarfFDECache<A>::entry *
158DwarfFDECache<A>::_bufferUsed = _initialBuffer;
159
160template <typename A>
161typename DwarfFDECache<A>::entry *
162DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
163
164template <typename A>
165typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
166
167template <typename A>
168RWMutex DwarfFDECache<A>::_lock;
169
170#ifdef __APPLE__
171template <typename A>
172bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
173#endif
174
175template <typename A>
176typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) {
177 pint_t result = 0;
178 _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
179 for (entry *p = _buffer; p < _bufferUsed; ++p) {
180 if ((mh == p->mh) || (mh == kSearchAll)) {
181 if ((p->ip_start <= pc) && (pc < p->ip_end)) {
182 result = p->fde;
183 break;
184 }
185 }
186 }
187 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
188 return result;
189}
190
191template <typename A>
192void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
193 pint_t fde) {
194#if !defined(_LIBUNWIND_NO_HEAP)
195 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
196 if (_bufferUsed >= _bufferEnd) {
197 size_t oldSize = (size_t)(_bufferEnd - _buffer);
198 size_t newSize = oldSize * 4;
199 // Can't use operator new (we are below it).
200 entry *newBuffer = (entry *)malloc(size: newSize * sizeof(entry));
201 memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
202 if (_buffer != _initialBuffer)
203 free(_buffer);
204 _buffer = newBuffer;
205 _bufferUsed = &newBuffer[oldSize];
206 _bufferEnd = &newBuffer[newSize];
207 }
208 _bufferUsed->mh = mh;
209 _bufferUsed->ip_start = ip_start;
210 _bufferUsed->ip_end = ip_end;
211 _bufferUsed->fde = fde;
212 ++_bufferUsed;
213#ifdef __APPLE__
214 if (!_registeredForDyldUnloads) {
215 _dyld_register_func_for_remove_image(&dyldUnloadHook);
216 _registeredForDyldUnloads = true;
217 }
218#endif
219 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
220#endif
221}
222
223template <typename A>
224void DwarfFDECache<A>::removeAllIn(pint_t mh) {
225 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
226 entry *d = _buffer;
227 for (const entry *s = _buffer; s < _bufferUsed; ++s) {
228 if (s->mh != mh) {
229 if (d != s)
230 *d = *s;
231 ++d;
232 }
233 }
234 _bufferUsed = d;
235 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
236}
237
238#ifdef __APPLE__
239template <typename A>
240void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
241 removeAllIn((pint_t) mh);
242}
243#endif
244
245template <typename A>
246void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
247 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
248 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
249 for (entry *p = _buffer; p < _bufferUsed; ++p) {
250 (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
251 }
252 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
253}
254#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
255
256#define arrayoffsetof(type, index, field) \
257 (sizeof(type) * (index) + offsetof(type, field))
258
259#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
260template <typename A> class UnwindSectionHeader {
261public:
262 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
263 : _addressSpace(addressSpace), _addr(addr) {}
264
265 uint32_t version() const {
266 return _addressSpace.get32(_addr +
267 offsetof(unwind_info_section_header, version));
268 }
269 uint32_t commonEncodingsArraySectionOffset() const {
270 return _addressSpace.get32(_addr +
271 offsetof(unwind_info_section_header,
272 commonEncodingsArraySectionOffset));
273 }
274 uint32_t commonEncodingsArrayCount() const {
275 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
276 commonEncodingsArrayCount));
277 }
278 uint32_t personalityArraySectionOffset() const {
279 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
280 personalityArraySectionOffset));
281 }
282 uint32_t personalityArrayCount() const {
283 return _addressSpace.get32(
284 _addr + offsetof(unwind_info_section_header, personalityArrayCount));
285 }
286 uint32_t indexSectionOffset() const {
287 return _addressSpace.get32(
288 _addr + offsetof(unwind_info_section_header, indexSectionOffset));
289 }
290 uint32_t indexCount() const {
291 return _addressSpace.get32(
292 _addr + offsetof(unwind_info_section_header, indexCount));
293 }
294
295private:
296 A &_addressSpace;
297 typename A::pint_t _addr;
298};
299
300template <typename A> class UnwindSectionIndexArray {
301public:
302 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
303 : _addressSpace(addressSpace), _addr(addr) {}
304
305 uint32_t functionOffset(uint32_t index) const {
306 return _addressSpace.get32(
307 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
308 functionOffset));
309 }
310 uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
311 return _addressSpace.get32(
312 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
313 secondLevelPagesSectionOffset));
314 }
315 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
316 return _addressSpace.get32(
317 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
318 lsdaIndexArraySectionOffset));
319 }
320
321private:
322 A &_addressSpace;
323 typename A::pint_t _addr;
324};
325
326template <typename A> class UnwindSectionRegularPageHeader {
327public:
328 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
329 : _addressSpace(addressSpace), _addr(addr) {}
330
331 uint32_t kind() const {
332 return _addressSpace.get32(
333 _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
334 }
335 uint16_t entryPageOffset() const {
336 return _addressSpace.get16(
337 _addr + offsetof(unwind_info_regular_second_level_page_header,
338 entryPageOffset));
339 }
340 uint16_t entryCount() const {
341 return _addressSpace.get16(
342 _addr +
343 offsetof(unwind_info_regular_second_level_page_header, entryCount));
344 }
345
346private:
347 A &_addressSpace;
348 typename A::pint_t _addr;
349};
350
351template <typename A> class UnwindSectionRegularArray {
352public:
353 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
354 : _addressSpace(addressSpace), _addr(addr) {}
355
356 uint32_t functionOffset(uint32_t index) const {
357 return _addressSpace.get32(
358 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
359 functionOffset));
360 }
361 uint32_t encoding(uint32_t index) const {
362 return _addressSpace.get32(
363 _addr +
364 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
365 }
366
367private:
368 A &_addressSpace;
369 typename A::pint_t _addr;
370};
371
372template <typename A> class UnwindSectionCompressedPageHeader {
373public:
374 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
375 : _addressSpace(addressSpace), _addr(addr) {}
376
377 uint32_t kind() const {
378 return _addressSpace.get32(
379 _addr +
380 offsetof(unwind_info_compressed_second_level_page_header, kind));
381 }
382 uint16_t entryPageOffset() const {
383 return _addressSpace.get16(
384 _addr + offsetof(unwind_info_compressed_second_level_page_header,
385 entryPageOffset));
386 }
387 uint16_t entryCount() const {
388 return _addressSpace.get16(
389 _addr +
390 offsetof(unwind_info_compressed_second_level_page_header, entryCount));
391 }
392 uint16_t encodingsPageOffset() const {
393 return _addressSpace.get16(
394 _addr + offsetof(unwind_info_compressed_second_level_page_header,
395 encodingsPageOffset));
396 }
397 uint16_t encodingsCount() const {
398 return _addressSpace.get16(
399 _addr + offsetof(unwind_info_compressed_second_level_page_header,
400 encodingsCount));
401 }
402
403private:
404 A &_addressSpace;
405 typename A::pint_t _addr;
406};
407
408template <typename A> class UnwindSectionCompressedArray {
409public:
410 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
411 : _addressSpace(addressSpace), _addr(addr) {}
412
413 uint32_t functionOffset(uint32_t index) const {
414 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
415 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
416 }
417 uint16_t encodingIndex(uint32_t index) const {
418 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
419 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
420 }
421
422private:
423 A &_addressSpace;
424 typename A::pint_t _addr;
425};
426
427template <typename A> class UnwindSectionLsdaArray {
428public:
429 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
430 : _addressSpace(addressSpace), _addr(addr) {}
431
432 uint32_t functionOffset(uint32_t index) const {
433 return _addressSpace.get32(
434 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
435 index, functionOffset));
436 }
437 uint32_t lsdaOffset(uint32_t index) const {
438 return _addressSpace.get32(
439 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
440 index, lsdaOffset));
441 }
442
443private:
444 A &_addressSpace;
445 typename A::pint_t _addr;
446};
447#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
448
449class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
450public:
451 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
452 // This avoids an unnecessary dependency to libc++abi.
453 void operator delete(void *, size_t) {}
454
455 virtual ~AbstractUnwindCursor() {}
456 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
457 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
458 virtual void setReg(int, unw_word_t) {
459 _LIBUNWIND_ABORT("setReg not implemented");
460 }
461 virtual bool validFloatReg(int) {
462 _LIBUNWIND_ABORT("validFloatReg not implemented");
463 }
464 virtual unw_fpreg_t getFloatReg(int) {
465 _LIBUNWIND_ABORT("getFloatReg not implemented");
466 }
467 virtual void setFloatReg(int, unw_fpreg_t) {
468 _LIBUNWIND_ABORT("setFloatReg not implemented");
469 }
470 virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); }
471 virtual void getInfo(unw_proc_info_t *) {
472 _LIBUNWIND_ABORT("getInfo not implemented");
473 }
474 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
475 virtual bool isSignalFrame() {
476 _LIBUNWIND_ABORT("isSignalFrame not implemented");
477 }
478 virtual bool getFunctionName(char *, size_t, unw_word_t *) {
479 _LIBUNWIND_ABORT("getFunctionName not implemented");
480 }
481 virtual void setInfoBasedOnIPRegister(bool = false) {
482 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
483 }
484 virtual const char *getRegisterName(int) {
485 _LIBUNWIND_ABORT("getRegisterName not implemented");
486 }
487#ifdef __arm__
488 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
489#endif
490
491#ifdef _AIX
492 virtual uintptr_t getDataRelBase() {
493 _LIBUNWIND_ABORT("getDataRelBase not implemented");
494 }
495#endif
496
497#if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
498 virtual void *get_registers() {
499 _LIBUNWIND_ABORT("get_registers not implemented");
500 }
501#endif
502};
503
504#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
505
506/// \c UnwindCursor contains all state (including all register values) during
507/// an unwind. This is normally stack-allocated inside a unw_cursor_t.
508template <typename A, typename R>
509class UnwindCursor : public AbstractUnwindCursor {
510 typedef typename A::pint_t pint_t;
511public:
512 UnwindCursor(unw_context_t *context, A &as);
513 UnwindCursor(CONTEXT *context, A &as);
514 UnwindCursor(A &as, void *threadArg);
515 virtual ~UnwindCursor() {}
516 virtual bool validReg(int);
517 virtual unw_word_t getReg(int);
518 virtual void setReg(int, unw_word_t);
519 virtual bool validFloatReg(int);
520 virtual unw_fpreg_t getFloatReg(int);
521 virtual void setFloatReg(int, unw_fpreg_t);
522 virtual int step(bool = false);
523 virtual void getInfo(unw_proc_info_t *);
524 virtual void jumpto();
525 virtual bool isSignalFrame();
526 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
527 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
528 virtual const char *getRegisterName(int num);
529#ifdef __arm__
530 virtual void saveVFPAsX();
531#endif
532
533 DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
534 void setDispatcherContext(DISPATCHER_CONTEXT *disp) {
535 _dispContext = *disp;
536 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
537 if (_dispContext.LanguageHandler) {
538 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
539 } else
540 _info.handler = 0;
541 }
542
543 // libunwind does not and should not depend on C++ library which means that we
544 // need our own definition of inline placement new.
545 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
546
547private:
548
549 pint_t getLastPC() const { return _dispContext.ControlPc; }
550 void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
551 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
552#ifdef __arm__
553 // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit.
554 pc &= ~1U;
555#endif
556 // If pc points exactly at the end of the range, we might resolve the
557 // next function instead. Decrement pc by 1 to fit inside the current
558 // function.
559 pc -= 1;
560 _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
561 &_dispContext.ImageBase,
562 _dispContext.HistoryTable);
563 *base = _dispContext.ImageBase;
564 return _dispContext.FunctionEntry;
565 }
566 bool getInfoFromSEH(pint_t pc);
567 int stepWithSEHData() {
568 _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
569 _dispContext.ImageBase,
570 _dispContext.ControlPc,
571 _dispContext.FunctionEntry,
572 _dispContext.ContextRecord,
573 &_dispContext.HandlerData,
574 &_dispContext.EstablisherFrame,
575 NULL);
576 // Update some fields of the unwind info now, since we have them.
577 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
578 if (_dispContext.LanguageHandler) {
579 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
580 } else
581 _info.handler = 0;
582 return UNW_STEP_SUCCESS;
583 }
584
585 A &_addressSpace;
586 unw_proc_info_t _info;
587 DISPATCHER_CONTEXT _dispContext;
588 CONTEXT _msContext;
589 UNWIND_HISTORY_TABLE _histTable;
590 bool _unwindInfoMissing;
591};
592
593
594template <typename A, typename R>
595UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
596 : _addressSpace(as), _unwindInfoMissing(false) {
597 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
598 "UnwindCursor<> does not fit in unw_cursor_t");
599 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
600 "UnwindCursor<> requires more alignment than unw_cursor_t");
601 memset(&_info, 0, sizeof(_info));
602 memset(&_histTable, 0, sizeof(_histTable));
603 memset(&_dispContext, 0, sizeof(_dispContext));
604 _dispContext.ContextRecord = &_msContext;
605 _dispContext.HistoryTable = &_histTable;
606 // Initialize MS context from ours.
607 R r(context);
608 RtlCaptureContext(&_msContext);
609 _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
610#if defined(_LIBUNWIND_TARGET_X86_64)
611 _msContext.Rax = r.getRegister(UNW_X86_64_RAX);
612 _msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
613 _msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
614 _msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
615 _msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
616 _msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
617 _msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
618 _msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
619 _msContext.R8 = r.getRegister(UNW_X86_64_R8);
620 _msContext.R9 = r.getRegister(UNW_X86_64_R9);
621 _msContext.R10 = r.getRegister(UNW_X86_64_R10);
622 _msContext.R11 = r.getRegister(UNW_X86_64_R11);
623 _msContext.R12 = r.getRegister(UNW_X86_64_R12);
624 _msContext.R13 = r.getRegister(UNW_X86_64_R13);
625 _msContext.R14 = r.getRegister(UNW_X86_64_R14);
626 _msContext.R15 = r.getRegister(UNW_X86_64_R15);
627 _msContext.Rip = r.getRegister(UNW_REG_IP);
628 union {
629 v128 v;
630 M128A m;
631 } t;
632 t.v = r.getVectorRegister(UNW_X86_64_XMM0);
633 _msContext.Xmm0 = t.m;
634 t.v = r.getVectorRegister(UNW_X86_64_XMM1);
635 _msContext.Xmm1 = t.m;
636 t.v = r.getVectorRegister(UNW_X86_64_XMM2);
637 _msContext.Xmm2 = t.m;
638 t.v = r.getVectorRegister(UNW_X86_64_XMM3);
639 _msContext.Xmm3 = t.m;
640 t.v = r.getVectorRegister(UNW_X86_64_XMM4);
641 _msContext.Xmm4 = t.m;
642 t.v = r.getVectorRegister(UNW_X86_64_XMM5);
643 _msContext.Xmm5 = t.m;
644 t.v = r.getVectorRegister(UNW_X86_64_XMM6);
645 _msContext.Xmm6 = t.m;
646 t.v = r.getVectorRegister(UNW_X86_64_XMM7);
647 _msContext.Xmm7 = t.m;
648 t.v = r.getVectorRegister(UNW_X86_64_XMM8);
649 _msContext.Xmm8 = t.m;
650 t.v = r.getVectorRegister(UNW_X86_64_XMM9);
651 _msContext.Xmm9 = t.m;
652 t.v = r.getVectorRegister(UNW_X86_64_XMM10);
653 _msContext.Xmm10 = t.m;
654 t.v = r.getVectorRegister(UNW_X86_64_XMM11);
655 _msContext.Xmm11 = t.m;
656 t.v = r.getVectorRegister(UNW_X86_64_XMM12);
657 _msContext.Xmm12 = t.m;
658 t.v = r.getVectorRegister(UNW_X86_64_XMM13);
659 _msContext.Xmm13 = t.m;
660 t.v = r.getVectorRegister(UNW_X86_64_XMM14);
661 _msContext.Xmm14 = t.m;
662 t.v = r.getVectorRegister(UNW_X86_64_XMM15);
663 _msContext.Xmm15 = t.m;
664#elif defined(_LIBUNWIND_TARGET_ARM)
665 _msContext.R0 = r.getRegister(UNW_ARM_R0);
666 _msContext.R1 = r.getRegister(UNW_ARM_R1);
667 _msContext.R2 = r.getRegister(UNW_ARM_R2);
668 _msContext.R3 = r.getRegister(UNW_ARM_R3);
669 _msContext.R4 = r.getRegister(UNW_ARM_R4);
670 _msContext.R5 = r.getRegister(UNW_ARM_R5);
671 _msContext.R6 = r.getRegister(UNW_ARM_R6);
672 _msContext.R7 = r.getRegister(UNW_ARM_R7);
673 _msContext.R8 = r.getRegister(UNW_ARM_R8);
674 _msContext.R9 = r.getRegister(UNW_ARM_R9);
675 _msContext.R10 = r.getRegister(UNW_ARM_R10);
676 _msContext.R11 = r.getRegister(UNW_ARM_R11);
677 _msContext.R12 = r.getRegister(UNW_ARM_R12);
678 _msContext.Sp = r.getRegister(UNW_ARM_SP);
679 _msContext.Lr = r.getRegister(UNW_ARM_LR);
680 _msContext.Pc = r.getRegister(UNW_ARM_IP);
681 for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
682 union {
683 uint64_t w;
684 double d;
685 } d;
686 d.d = r.getFloatRegister(i);
687 _msContext.D[i - UNW_ARM_D0] = d.w;
688 }
689#elif defined(_LIBUNWIND_TARGET_AARCH64)
690 for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
691 _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
692 _msContext.Sp = r.getRegister(UNW_REG_SP);
693 _msContext.Pc = r.getRegister(UNW_REG_IP);
694 for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
695 _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
696#endif
697}
698
699template <typename A, typename R>
700UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
701 : _addressSpace(as), _unwindInfoMissing(false) {
702 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
703 "UnwindCursor<> does not fit in unw_cursor_t");
704 memset(&_info, 0, sizeof(_info));
705 memset(&_histTable, 0, sizeof(_histTable));
706 memset(&_dispContext, 0, sizeof(_dispContext));
707 _dispContext.ContextRecord = &_msContext;
708 _dispContext.HistoryTable = &_histTable;
709 _msContext = *context;
710}
711
712
713template <typename A, typename R>
714bool UnwindCursor<A, R>::validReg(int regNum) {
715 if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
716#if defined(_LIBUNWIND_TARGET_X86_64)
717 if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_RIP) return true;
718#elif defined(_LIBUNWIND_TARGET_ARM)
719 if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
720 regNum == UNW_ARM_RA_AUTH_CODE)
721 return true;
722#elif defined(_LIBUNWIND_TARGET_AARCH64)
723 if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
724#endif
725 return false;
726}
727
728template <typename A, typename R>
729unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
730 switch (regNum) {
731#if defined(_LIBUNWIND_TARGET_X86_64)
732 case UNW_X86_64_RIP:
733 case UNW_REG_IP: return _msContext.Rip;
734 case UNW_X86_64_RAX: return _msContext.Rax;
735 case UNW_X86_64_RDX: return _msContext.Rdx;
736 case UNW_X86_64_RCX: return _msContext.Rcx;
737 case UNW_X86_64_RBX: return _msContext.Rbx;
738 case UNW_REG_SP:
739 case UNW_X86_64_RSP: return _msContext.Rsp;
740 case UNW_X86_64_RBP: return _msContext.Rbp;
741 case UNW_X86_64_RSI: return _msContext.Rsi;
742 case UNW_X86_64_RDI: return _msContext.Rdi;
743 case UNW_X86_64_R8: return _msContext.R8;
744 case UNW_X86_64_R9: return _msContext.R9;
745 case UNW_X86_64_R10: return _msContext.R10;
746 case UNW_X86_64_R11: return _msContext.R11;
747 case UNW_X86_64_R12: return _msContext.R12;
748 case UNW_X86_64_R13: return _msContext.R13;
749 case UNW_X86_64_R14: return _msContext.R14;
750 case UNW_X86_64_R15: return _msContext.R15;
751#elif defined(_LIBUNWIND_TARGET_ARM)
752 case UNW_ARM_R0: return _msContext.R0;
753 case UNW_ARM_R1: return _msContext.R1;
754 case UNW_ARM_R2: return _msContext.R2;
755 case UNW_ARM_R3: return _msContext.R3;
756 case UNW_ARM_R4: return _msContext.R4;
757 case UNW_ARM_R5: return _msContext.R5;
758 case UNW_ARM_R6: return _msContext.R6;
759 case UNW_ARM_R7: return _msContext.R7;
760 case UNW_ARM_R8: return _msContext.R8;
761 case UNW_ARM_R9: return _msContext.R9;
762 case UNW_ARM_R10: return _msContext.R10;
763 case UNW_ARM_R11: return _msContext.R11;
764 case UNW_ARM_R12: return _msContext.R12;
765 case UNW_REG_SP:
766 case UNW_ARM_SP: return _msContext.Sp;
767 case UNW_ARM_LR: return _msContext.Lr;
768 case UNW_REG_IP:
769 case UNW_ARM_IP: return _msContext.Pc;
770#elif defined(_LIBUNWIND_TARGET_AARCH64)
771 case UNW_REG_SP: return _msContext.Sp;
772 case UNW_REG_IP: return _msContext.Pc;
773 default: return _msContext.X[regNum - UNW_AARCH64_X0];
774#endif
775 }
776 _LIBUNWIND_ABORT("unsupported register");
777}
778
779template <typename A, typename R>
780void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
781 switch (regNum) {
782#if defined(_LIBUNWIND_TARGET_X86_64)
783 case UNW_X86_64_RIP:
784 case UNW_REG_IP: _msContext.Rip = value; break;
785 case UNW_X86_64_RAX: _msContext.Rax = value; break;
786 case UNW_X86_64_RDX: _msContext.Rdx = value; break;
787 case UNW_X86_64_RCX: _msContext.Rcx = value; break;
788 case UNW_X86_64_RBX: _msContext.Rbx = value; break;
789 case UNW_REG_SP:
790 case UNW_X86_64_RSP: _msContext.Rsp = value; break;
791 case UNW_X86_64_RBP: _msContext.Rbp = value; break;
792 case UNW_X86_64_RSI: _msContext.Rsi = value; break;
793 case UNW_X86_64_RDI: _msContext.Rdi = value; break;
794 case UNW_X86_64_R8: _msContext.R8 = value; break;
795 case UNW_X86_64_R9: _msContext.R9 = value; break;
796 case UNW_X86_64_R10: _msContext.R10 = value; break;
797 case UNW_X86_64_R11: _msContext.R11 = value; break;
798 case UNW_X86_64_R12: _msContext.R12 = value; break;
799 case UNW_X86_64_R13: _msContext.R13 = value; break;
800 case UNW_X86_64_R14: _msContext.R14 = value; break;
801 case UNW_X86_64_R15: _msContext.R15 = value; break;
802#elif defined(_LIBUNWIND_TARGET_ARM)
803 case UNW_ARM_R0: _msContext.R0 = value; break;
804 case UNW_ARM_R1: _msContext.R1 = value; break;
805 case UNW_ARM_R2: _msContext.R2 = value; break;
806 case UNW_ARM_R3: _msContext.R3 = value; break;
807 case UNW_ARM_R4: _msContext.R4 = value; break;
808 case UNW_ARM_R5: _msContext.R5 = value; break;
809 case UNW_ARM_R6: _msContext.R6 = value; break;
810 case UNW_ARM_R7: _msContext.R7 = value; break;
811 case UNW_ARM_R8: _msContext.R8 = value; break;
812 case UNW_ARM_R9: _msContext.R9 = value; break;
813 case UNW_ARM_R10: _msContext.R10 = value; break;
814 case UNW_ARM_R11: _msContext.R11 = value; break;
815 case UNW_ARM_R12: _msContext.R12 = value; break;
816 case UNW_REG_SP:
817 case UNW_ARM_SP: _msContext.Sp = value; break;
818 case UNW_ARM_LR: _msContext.Lr = value; break;
819 case UNW_REG_IP:
820 case UNW_ARM_IP: _msContext.Pc = value; break;
821#elif defined(_LIBUNWIND_TARGET_AARCH64)
822 case UNW_REG_SP: _msContext.Sp = value; break;
823 case UNW_REG_IP: _msContext.Pc = value; break;
824 case UNW_AARCH64_X0:
825 case UNW_AARCH64_X1:
826 case UNW_AARCH64_X2:
827 case UNW_AARCH64_X3:
828 case UNW_AARCH64_X4:
829 case UNW_AARCH64_X5:
830 case UNW_AARCH64_X6:
831 case UNW_AARCH64_X7:
832 case UNW_AARCH64_X8:
833 case UNW_AARCH64_X9:
834 case UNW_AARCH64_X10:
835 case UNW_AARCH64_X11:
836 case UNW_AARCH64_X12:
837 case UNW_AARCH64_X13:
838 case UNW_AARCH64_X14:
839 case UNW_AARCH64_X15:
840 case UNW_AARCH64_X16:
841 case UNW_AARCH64_X17:
842 case UNW_AARCH64_X18:
843 case UNW_AARCH64_X19:
844 case UNW_AARCH64_X20:
845 case UNW_AARCH64_X21:
846 case UNW_AARCH64_X22:
847 case UNW_AARCH64_X23:
848 case UNW_AARCH64_X24:
849 case UNW_AARCH64_X25:
850 case UNW_AARCH64_X26:
851 case UNW_AARCH64_X27:
852 case UNW_AARCH64_X28:
853 case UNW_AARCH64_FP:
854 case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
855#endif
856 default:
857 _LIBUNWIND_ABORT("unsupported register");
858 }
859}
860
861template <typename A, typename R>
862bool UnwindCursor<A, R>::validFloatReg(int regNum) {
863#if defined(_LIBUNWIND_TARGET_ARM)
864 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
865 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
866#elif defined(_LIBUNWIND_TARGET_AARCH64)
867 if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
868#else
869 (void)regNum;
870#endif
871 return false;
872}
873
874template <typename A, typename R>
875unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
876#if defined(_LIBUNWIND_TARGET_ARM)
877 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
878 union {
879 uint32_t w;
880 float f;
881 } d;
882 d.w = _msContext.S[regNum - UNW_ARM_S0];
883 return d.f;
884 }
885 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
886 union {
887 uint64_t w;
888 double d;
889 } d;
890 d.w = _msContext.D[regNum - UNW_ARM_D0];
891 return d.d;
892 }
893 _LIBUNWIND_ABORT("unsupported float register");
894#elif defined(_LIBUNWIND_TARGET_AARCH64)
895 return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
896#else
897 (void)regNum;
898 _LIBUNWIND_ABORT("float registers unimplemented");
899#endif
900}
901
902template <typename A, typename R>
903void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
904#if defined(_LIBUNWIND_TARGET_ARM)
905 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
906 union {
907 uint32_t w;
908 float f;
909 } d;
910 d.f = (float)value;
911 _msContext.S[regNum - UNW_ARM_S0] = d.w;
912 }
913 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
914 union {
915 uint64_t w;
916 double d;
917 } d;
918 d.d = value;
919 _msContext.D[regNum - UNW_ARM_D0] = d.w;
920 }
921 _LIBUNWIND_ABORT("unsupported float register");
922#elif defined(_LIBUNWIND_TARGET_AARCH64)
923 _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
924#else
925 (void)regNum;
926 (void)value;
927 _LIBUNWIND_ABORT("float registers unimplemented");
928#endif
929}
930
931template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
932 RtlRestoreContext(&_msContext, nullptr);
933}
934
935#ifdef __arm__
936template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
937#endif
938
939template <typename A, typename R>
940const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
941 return R::getRegisterName(regNum);
942}
943
944template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
945 return false;
946}
947
948#else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
949
950/// UnwindCursor contains all state (including all register values) during
951/// an unwind. This is normally stack allocated inside a unw_cursor_t.
952template <typename A, typename R>
953class UnwindCursor : public AbstractUnwindCursor{
954 typedef typename A::pint_t pint_t;
955public:
956 UnwindCursor(unw_context_t *context, A &as);
957 UnwindCursor(A &as, void *threadArg);
958 virtual ~UnwindCursor() {}
959 virtual bool validReg(int);
960 virtual unw_word_t getReg(int);
961 virtual void setReg(int, unw_word_t);
962 virtual bool validFloatReg(int);
963 virtual unw_fpreg_t getFloatReg(int);
964 virtual void setFloatReg(int, unw_fpreg_t);
965 virtual int step(bool stage2 = false);
966 virtual void getInfo(unw_proc_info_t *);
967 virtual void jumpto();
968 virtual bool isSignalFrame();
969 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
970 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
971 virtual const char *getRegisterName(int num);
972#ifdef __arm__
973 virtual void saveVFPAsX();
974#endif
975
976#ifdef _AIX
977 virtual uintptr_t getDataRelBase();
978#endif
979
980#if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
981 virtual void *get_registers() { return &_registers; }
982#endif
983
984 // libunwind does not and should not depend on C++ library which means that we
985 // need our own definition of inline placement new.
986 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
987
988private:
989
990#if defined(_LIBUNWIND_ARM_EHABI)
991 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections &sects);
992
993 int stepWithEHABI() {
994 size_t len = 0;
995 size_t off = 0;
996 // FIXME: Calling decode_eht_entry() here is violating the libunwind
997 // abstraction layer.
998 const uint32_t *ehtp =
999 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
1000 &off, &len);
1001 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
1002 _URC_CONTINUE_UNWIND)
1003 return UNW_STEP_END;
1004 return UNW_STEP_SUCCESS;
1005 }
1006#endif
1007
1008#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
1009 bool setInfoForSigReturn() {
1010 R dummy;
1011 return setInfoForSigReturn(dummy);
1012 }
1013 int stepThroughSigReturn() {
1014 R dummy;
1015 return stepThroughSigReturn(dummy);
1016 }
1017 bool isReadableAddr(const pint_t addr) const;
1018#if defined(_LIBUNWIND_TARGET_AARCH64)
1019 bool setInfoForSigReturn(Registers_arm64 &);
1020 int stepThroughSigReturn(Registers_arm64 &);
1021#endif
1022#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1023 bool setInfoForSigReturn(Registers_loongarch &);
1024 int stepThroughSigReturn(Registers_loongarch &);
1025#endif
1026#if defined(_LIBUNWIND_TARGET_RISCV)
1027 bool setInfoForSigReturn(Registers_riscv &);
1028 int stepThroughSigReturn(Registers_riscv &);
1029#endif
1030#if defined(_LIBUNWIND_TARGET_S390X)
1031 bool setInfoForSigReturn(Registers_s390x &);
1032 int stepThroughSigReturn(Registers_s390x &);
1033#endif
1034 template <typename Registers> bool setInfoForSigReturn(Registers &) {
1035 return false;
1036 }
1037 template <typename Registers> int stepThroughSigReturn(Registers &) {
1038 return UNW_STEP_END;
1039 }
1040#elif defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
1041 bool setInfoForSigReturn();
1042 int stepThroughSigReturn();
1043#endif
1044
1045#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1046 bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1047 const typename CFI_Parser<A>::CIE_Info &cieInfo,
1048 pint_t pc, uintptr_t dso_base);
1049 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections &sects,
1050 uint32_t fdeSectionOffsetHint=0);
1051 int stepWithDwarfFDE(bool stage2) {
1052 return DwarfInstructions<A, R>::stepWithDwarf(
1053 _addressSpace, (pint_t)this->getReg(UNW_REG_IP),
1054 (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2);
1055 }
1056#endif
1057
1058#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1059 bool getInfoFromCompactEncodingSection(pint_t pc,
1060 const UnwindInfoSections &sects);
1061 int stepWithCompactEncoding(bool stage2 = false) {
1062#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1063 if ( compactSaysUseDwarf() )
1064 return stepWithDwarfFDE(stage2);
1065#endif
1066 R dummy;
1067 return stepWithCompactEncoding(dummy);
1068 }
1069
1070#if defined(_LIBUNWIND_TARGET_X86_64)
1071 int stepWithCompactEncoding(Registers_x86_64 &) {
1072 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
1073 _info.format, _info.start_ip, _addressSpace, _registers);
1074 }
1075#endif
1076
1077#if defined(_LIBUNWIND_TARGET_I386)
1078 int stepWithCompactEncoding(Registers_x86 &) {
1079 return CompactUnwinder_x86<A>::stepWithCompactEncoding(
1080 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
1081 }
1082#endif
1083
1084#if defined(_LIBUNWIND_TARGET_PPC)
1085 int stepWithCompactEncoding(Registers_ppc &) {
1086 return UNW_EINVAL;
1087 }
1088#endif
1089
1090#if defined(_LIBUNWIND_TARGET_PPC64)
1091 int stepWithCompactEncoding(Registers_ppc64 &) {
1092 return UNW_EINVAL;
1093 }
1094#endif
1095
1096
1097#if defined(_LIBUNWIND_TARGET_AARCH64)
1098 int stepWithCompactEncoding(Registers_arm64 &) {
1099 return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
1100 _info.format, _info.start_ip, _addressSpace, _registers);
1101 }
1102#endif
1103
1104#if defined(_LIBUNWIND_TARGET_MIPS_O32)
1105 int stepWithCompactEncoding(Registers_mips_o32 &) {
1106 return UNW_EINVAL;
1107 }
1108#endif
1109
1110#if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
1111 int stepWithCompactEncoding(Registers_mips_newabi &) {
1112 return UNW_EINVAL;
1113 }
1114#endif
1115
1116#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1117 int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; }
1118#endif
1119
1120#if defined(_LIBUNWIND_TARGET_SPARC)
1121 int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
1122#endif
1123
1124#if defined(_LIBUNWIND_TARGET_SPARC64)
1125 int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
1126#endif
1127
1128#if defined (_LIBUNWIND_TARGET_RISCV)
1129 int stepWithCompactEncoding(Registers_riscv &) {
1130 return UNW_EINVAL;
1131 }
1132#endif
1133
1134 bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
1135 R dummy;
1136 return compactSaysUseDwarf(dummy, offset);
1137 }
1138
1139#if defined(_LIBUNWIND_TARGET_X86_64)
1140 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
1141 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
1142 if (offset)
1143 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
1144 return true;
1145 }
1146 return false;
1147 }
1148#endif
1149
1150#if defined(_LIBUNWIND_TARGET_I386)
1151 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
1152 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
1153 if (offset)
1154 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
1155 return true;
1156 }
1157 return false;
1158 }
1159#endif
1160
1161#if defined(_LIBUNWIND_TARGET_PPC)
1162 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
1163 return true;
1164 }
1165#endif
1166
1167#if defined(_LIBUNWIND_TARGET_PPC64)
1168 bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
1169 return true;
1170 }
1171#endif
1172
1173#if defined(_LIBUNWIND_TARGET_AARCH64)
1174 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
1175 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
1176 if (offset)
1177 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
1178 return true;
1179 }
1180 return false;
1181 }
1182#endif
1183
1184#if defined(_LIBUNWIND_TARGET_MIPS_O32)
1185 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
1186 return true;
1187 }
1188#endif
1189
1190#if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
1191 bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
1192 return true;
1193 }
1194#endif
1195
1196#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1197 bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const {
1198 return true;
1199 }
1200#endif
1201
1202#if defined(_LIBUNWIND_TARGET_SPARC)
1203 bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
1204#endif
1205
1206#if defined(_LIBUNWIND_TARGET_SPARC64)
1207 bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
1208 return true;
1209 }
1210#endif
1211
1212#if defined (_LIBUNWIND_TARGET_RISCV)
1213 bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
1214 return true;
1215 }
1216#endif
1217
1218#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1219
1220#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1221 compact_unwind_encoding_t dwarfEncoding() const {
1222 R dummy;
1223 return dwarfEncoding(dummy);
1224 }
1225
1226#if defined(_LIBUNWIND_TARGET_X86_64)
1227 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
1228 return UNWIND_X86_64_MODE_DWARF;
1229 }
1230#endif
1231
1232#if defined(_LIBUNWIND_TARGET_I386)
1233 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
1234 return UNWIND_X86_MODE_DWARF;
1235 }
1236#endif
1237
1238#if defined(_LIBUNWIND_TARGET_PPC)
1239 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
1240 return 0;
1241 }
1242#endif
1243
1244#if defined(_LIBUNWIND_TARGET_PPC64)
1245 compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
1246 return 0;
1247 }
1248#endif
1249
1250#if defined(_LIBUNWIND_TARGET_AARCH64)
1251 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
1252 return UNWIND_ARM64_MODE_DWARF;
1253 }
1254#endif
1255
1256#if defined(_LIBUNWIND_TARGET_ARM)
1257 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
1258 return 0;
1259 }
1260#endif
1261
1262#if defined (_LIBUNWIND_TARGET_OR1K)
1263 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
1264 return 0;
1265 }
1266#endif
1267
1268#if defined (_LIBUNWIND_TARGET_HEXAGON)
1269 compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
1270 return 0;
1271 }
1272#endif
1273
1274#if defined (_LIBUNWIND_TARGET_MIPS_O32)
1275 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
1276 return 0;
1277 }
1278#endif
1279
1280#if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
1281 compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
1282 return 0;
1283 }
1284#endif
1285
1286#if defined(_LIBUNWIND_TARGET_LOONGARCH)
1287 compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const {
1288 return 0;
1289 }
1290#endif
1291
1292#if defined(_LIBUNWIND_TARGET_SPARC)
1293 compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
1294#endif
1295
1296#if defined(_LIBUNWIND_TARGET_SPARC64)
1297 compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
1298 return 0;
1299 }
1300#endif
1301
1302#if defined (_LIBUNWIND_TARGET_RISCV)
1303 compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
1304 return 0;
1305 }
1306#endif
1307
1308#if defined (_LIBUNWIND_TARGET_S390X)
1309 compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const {
1310 return 0;
1311 }
1312#endif
1313
1314#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1315
1316#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1317 // For runtime environments using SEH unwind data without Windows runtime
1318 // support.
1319 pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
1320 void setLastPC(pint_t pc) { /* FIXME: Implement */ }
1321 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
1322 /* FIXME: Implement */
1323 *base = 0;
1324 return nullptr;
1325 }
1326 bool getInfoFromSEH(pint_t pc);
1327 int stepWithSEHData() { /* FIXME: Implement */ return 0; }
1328#endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1329
1330#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1331 bool getInfoFromTBTable(pint_t pc, R &registers);
1332 int stepWithTBTable(pint_t pc, tbtable *TBTable, R &registers,
1333 bool &isSignalFrame);
1334 int stepWithTBTableData() {
1335 return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
1336 reinterpret_cast<tbtable *>(_info.unwind_info),
1337 _registers, _isSignalFrame);
1338 }
1339#endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1340
1341 A &_addressSpace;
1342 R _registers;
1343 unw_proc_info_t _info;
1344 bool _unwindInfoMissing;
1345 bool _isSignalFrame;
1346#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
1347 defined(_LIBUNWIND_TARGET_HAIKU)
1348 bool _isSigReturn = false;
1349#endif
1350};
1351
1352
1353template <typename A, typename R>
1354UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
1355 : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
1356 _isSignalFrame(false) {
1357 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
1358 "UnwindCursor<> does not fit in unw_cursor_t");
1359 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
1360 "UnwindCursor<> requires more alignment than unw_cursor_t");
1361 memset(s: &_info, c: 0, n: sizeof(_info));
1362}
1363
1364template <typename A, typename R>
1365UnwindCursor<A, R>::UnwindCursor(A &as, void *)
1366 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
1367 memset(s: &_info, c: 0, n: sizeof(_info));
1368 // FIXME
1369 // fill in _registers from thread arg
1370}
1371
1372
1373template <typename A, typename R>
1374bool UnwindCursor<A, R>::validReg(int regNum) {
1375 return _registers.validRegister(regNum);
1376}
1377
1378template <typename A, typename R>
1379unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
1380 return _registers.getRegister(regNum);
1381}
1382
1383template <typename A, typename R>
1384void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
1385 _registers.setRegister(regNum, (typename A::pint_t)value);
1386}
1387
1388template <typename A, typename R>
1389bool UnwindCursor<A, R>::validFloatReg(int regNum) {
1390 return _registers.validFloatRegister(regNum);
1391}
1392
1393template <typename A, typename R>
1394unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
1395 return _registers.getFloatRegister(regNum);
1396}
1397
1398template <typename A, typename R>
1399void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
1400 _registers.setFloatRegister(regNum, value);
1401}
1402
1403template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
1404 _registers.jumpto();
1405}
1406
1407#ifdef __arm__
1408template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
1409 _registers.saveVFPAsX();
1410}
1411#endif
1412
1413#ifdef _AIX
1414template <typename A, typename R>
1415uintptr_t UnwindCursor<A, R>::getDataRelBase() {
1416 return reinterpret_cast<uintptr_t>(_info.extra);
1417}
1418#endif
1419
1420template <typename A, typename R>
1421const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
1422 return _registers.getRegisterName(regNum);
1423}
1424
1425template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
1426 return _isSignalFrame;
1427}
1428
1429#endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1430
1431#if defined(_LIBUNWIND_ARM_EHABI)
1432template<typename A>
1433struct EHABISectionIterator {
1434 typedef EHABISectionIterator _Self;
1435
1436 typedef typename A::pint_t value_type;
1437 typedef typename A::pint_t* pointer;
1438 typedef typename A::pint_t& reference;
1439 typedef size_t size_type;
1440 typedef size_t difference_type;
1441
1442 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
1443 return _Self(addressSpace, sects, 0);
1444 }
1445 static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
1446 return _Self(addressSpace, sects,
1447 sects.arm_section_length / sizeof(EHABIIndexEntry));
1448 }
1449
1450 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
1451 : _i(i), _addressSpace(&addressSpace), _sects(&sects) {}
1452
1453 _Self& operator++() { ++_i; return *this; }
1454 _Self& operator+=(size_t a) { _i += a; return *this; }
1455 _Self& operator--() { assert(_i > 0); --_i; return *this; }
1456 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
1457
1458 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
1459 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
1460
1461 size_t operator-(const _Self& other) const { return _i - other._i; }
1462
1463 bool operator==(const _Self& other) const {
1464 assert(_addressSpace == other._addressSpace);
1465 assert(_sects == other._sects);
1466 return _i == other._i;
1467 }
1468
1469 bool operator!=(const _Self& other) const {
1470 assert(_addressSpace == other._addressSpace);
1471 assert(_sects == other._sects);
1472 return _i != other._i;
1473 }
1474
1475 typename A::pint_t operator*() const { return functionAddress(); }
1476
1477 typename A::pint_t functionAddress() const {
1478 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1479 EHABIIndexEntry, _i, functionOffset);
1480 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
1481 }
1482
1483 typename A::pint_t dataAddress() {
1484 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1485 EHABIIndexEntry, _i, data);
1486 return indexAddr;
1487 }
1488
1489 private:
1490 size_t _i;
1491 A* _addressSpace;
1492 const UnwindInfoSections* _sects;
1493};
1494
1495namespace {
1496
1497template <typename A>
1498EHABISectionIterator<A> EHABISectionUpperBound(
1499 EHABISectionIterator<A> first,
1500 EHABISectionIterator<A> last,
1501 typename A::pint_t value) {
1502 size_t len = last - first;
1503 while (len > 0) {
1504 size_t l2 = len / 2;
1505 EHABISectionIterator<A> m = first + l2;
1506 if (value < *m) {
1507 len = l2;
1508 } else {
1509 first = ++m;
1510 len -= l2 + 1;
1511 }
1512 }
1513 return first;
1514}
1515
1516}
1517
1518template <typename A, typename R>
1519bool UnwindCursor<A, R>::getInfoFromEHABISection(
1520 pint_t pc,
1521 const UnwindInfoSections &sects) {
1522 EHABISectionIterator<A> begin =
1523 EHABISectionIterator<A>::begin(_addressSpace, sects);
1524 EHABISectionIterator<A> end =
1525 EHABISectionIterator<A>::end(_addressSpace, sects);
1526 if (begin == end)
1527 return false;
1528
1529 EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
1530 if (itNextPC == begin)
1531 return false;
1532 EHABISectionIterator<A> itThisPC = itNextPC - 1;
1533
1534 pint_t thisPC = itThisPC.functionAddress();
1535 // If an exception is thrown from a function, corresponding to the last entry
1536 // in the table, we don't really know the function extent and have to choose a
1537 // value for nextPC. Choosing max() will allow the range check during trace to
1538 // succeed.
1539 pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
1540 pint_t indexDataAddr = itThisPC.dataAddress();
1541
1542 if (indexDataAddr == 0)
1543 return false;
1544
1545 uint32_t indexData = _addressSpace.get32(indexDataAddr);
1546 if (indexData == UNW_EXIDX_CANTUNWIND)
1547 return false;
1548
1549 // If the high bit is set, the exception handling table entry is inline inside
1550 // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
1551 // the table points at an offset in the exception handling table (section 5
1552 // EHABI).
1553 pint_t exceptionTableAddr;
1554 uint32_t exceptionTableData;
1555 bool isSingleWordEHT;
1556 if (indexData & 0x80000000) {
1557 exceptionTableAddr = indexDataAddr;
1558 // TODO(ajwong): Should this data be 0?
1559 exceptionTableData = indexData;
1560 isSingleWordEHT = true;
1561 } else {
1562 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
1563 exceptionTableData = _addressSpace.get32(exceptionTableAddr);
1564 isSingleWordEHT = false;
1565 }
1566
1567 // Now we know the 3 things:
1568 // exceptionTableAddr -- exception handler table entry.
1569 // exceptionTableData -- the data inside the first word of the eht entry.
1570 // isSingleWordEHT -- whether the entry is in the index.
1571 unw_word_t personalityRoutine = 0xbadf00d;
1572 bool scope32 = false;
1573 uintptr_t lsda;
1574
1575 // If the high bit in the exception handling table entry is set, the entry is
1576 // in compact form (section 6.3 EHABI).
1577 if (exceptionTableData & 0x80000000) {
1578 // Grab the index of the personality routine from the compact form.
1579 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
1580 uint32_t extraWords = 0;
1581 switch (choice) {
1582 case 0:
1583 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
1584 extraWords = 0;
1585 scope32 = false;
1586 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
1587 break;
1588 case 1:
1589 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
1590 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1591 scope32 = false;
1592 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1593 break;
1594 case 2:
1595 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
1596 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1597 scope32 = true;
1598 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1599 break;
1600 default:
1601 _LIBUNWIND_ABORT("unknown personality routine");
1602 return false;
1603 }
1604
1605 if (isSingleWordEHT) {
1606 if (extraWords != 0) {
1607 _LIBUNWIND_ABORT("index inlined table detected but pr function "
1608 "requires extra words");
1609 return false;
1610 }
1611 }
1612 } else {
1613 pint_t personalityAddr =
1614 exceptionTableAddr + signExtendPrel31(exceptionTableData);
1615 personalityRoutine = personalityAddr;
1616
1617 // ARM EHABI # 6.2, # 9.2
1618 //
1619 // +---- ehtp
1620 // v
1621 // +--------------------------------------+
1622 // | +--------+--------+--------+-------+ |
1623 // | |0| prel31 to personalityRoutine | |
1624 // | +--------+--------+--------+-------+ |
1625 // | | N | unwind opcodes | | <-- UnwindData
1626 // | +--------+--------+--------+-------+ |
1627 // | | Word 2 unwind opcodes | |
1628 // | +--------+--------+--------+-------+ |
1629 // | ... |
1630 // | +--------+--------+--------+-------+ |
1631 // | | Word N unwind opcodes | |
1632 // | +--------+--------+--------+-------+ |
1633 // | | LSDA | | <-- lsda
1634 // | | ... | |
1635 // | +--------+--------+--------+-------+ |
1636 // +--------------------------------------+
1637
1638 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
1639 uint32_t FirstDataWord = *UnwindData;
1640 size_t N = ((FirstDataWord >> 24) & 0xff);
1641 size_t NDataWords = N + 1;
1642 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
1643 }
1644
1645 _info.start_ip = thisPC;
1646 _info.end_ip = nextPC;
1647 _info.handler = personalityRoutine;
1648 _info.unwind_info = exceptionTableAddr;
1649 _info.lsda = lsda;
1650 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
1651 _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum?
1652
1653 return true;
1654}
1655#endif
1656
1657#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1658template <typename A, typename R>
1659bool UnwindCursor<A, R>::getInfoFromFdeCie(
1660 const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1661 const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc,
1662 uintptr_t dso_base) {
1663 typename CFI_Parser<A>::PrologInfo prolog;
1664 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
1665 R::getArch(), &prolog)) {
1666 // Save off parsed FDE info
1667 _info.start_ip = fdeInfo.pcStart;
1668 _info.end_ip = fdeInfo.pcEnd;
1669 _info.lsda = fdeInfo.lsda;
1670 _info.handler = cieInfo.personality;
1671 // Some frameless functions need SP altered when resuming in function, so
1672 // propagate spExtraArgSize.
1673 _info.gp = prolog.spExtraArgSize;
1674 _info.flags = 0;
1675 _info.format = dwarfEncoding();
1676 _info.unwind_info = fdeInfo.fdeStart;
1677 _info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength);
1678 _info.extra = static_cast<unw_word_t>(dso_base);
1679 return true;
1680 }
1681 return false;
1682}
1683
1684template <typename A, typename R>
1685bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
1686 const UnwindInfoSections &sects,
1687 uint32_t fdeSectionOffsetHint) {
1688 typename CFI_Parser<A>::FDE_Info fdeInfo;
1689 typename CFI_Parser<A>::CIE_Info cieInfo;
1690 bool foundFDE = false;
1691 bool foundInCache = false;
1692 // If compact encoding table gave offset into dwarf section, go directly there
1693 if (fdeSectionOffsetHint != 0) {
1694 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1695 sects.dwarf_section_length,
1696 sects.dwarf_section + fdeSectionOffsetHint,
1697 &fdeInfo, &cieInfo);
1698 }
1699#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1700 if (!foundFDE && (sects.dwarf_index_section != 0)) {
1701 foundFDE = EHHeaderParser<A>::findFDE(
1702 _addressSpace, pc, sects.dwarf_index_section,
1703 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
1704 }
1705#endif
1706 if (!foundFDE) {
1707 // otherwise, search cache of previously found FDEs.
1708 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
1709 if (cachedFDE != 0) {
1710 foundFDE =
1711 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1712 sects.dwarf_section_length,
1713 cachedFDE, &fdeInfo, &cieInfo);
1714 foundInCache = foundFDE;
1715 }
1716 }
1717 if (!foundFDE) {
1718 // Still not found, do full scan of __eh_frame section.
1719 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1720 sects.dwarf_section_length, 0,
1721 &fdeInfo, &cieInfo);
1722 }
1723 if (foundFDE) {
1724 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, dso_base: sects.dso_base)) {
1725 // Add to cache (to make next lookup faster) if we had no hint
1726 // and there was no index.
1727 if (!foundInCache && (fdeSectionOffsetHint == 0)) {
1728 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1729 if (sects.dwarf_index_section == 0)
1730 #endif
1731 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
1732 fdeInfo.fdeStart);
1733 }
1734 return true;
1735 }
1736 }
1737 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
1738 return false;
1739}
1740#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1741
1742
1743#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1744template <typename A, typename R>
1745bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
1746 const UnwindInfoSections &sects) {
1747 const bool log = false;
1748 if (log)
1749 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
1750 (uint64_t)pc, (uint64_t)sects.dso_base);
1751
1752 const UnwindSectionHeader<A> sectionHeader(_addressSpace,
1753 sects.compact_unwind_section);
1754 if (sectionHeader.version() != UNWIND_SECTION_VERSION)
1755 return false;
1756
1757 // do a binary search of top level index to find page with unwind info
1758 pint_t targetFunctionOffset = pc - sects.dso_base;
1759 const UnwindSectionIndexArray<A> topIndex(_addressSpace,
1760 sects.compact_unwind_section
1761 + sectionHeader.indexSectionOffset());
1762 uint32_t low = 0;
1763 uint32_t high = sectionHeader.indexCount();
1764 uint32_t last = high - 1;
1765 while (low < high) {
1766 uint32_t mid = (low + high) / 2;
1767 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
1768 //mid, low, high, topIndex.functionOffset(mid));
1769 if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
1770 if ((mid == last) ||
1771 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
1772 low = mid;
1773 break;
1774 } else {
1775 low = mid + 1;
1776 }
1777 } else {
1778 high = mid;
1779 }
1780 }
1781 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
1782 const uint32_t firstLevelNextPageFunctionOffset =
1783 topIndex.functionOffset(low + 1);
1784 const pint_t secondLevelAddr =
1785 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
1786 const pint_t lsdaArrayStartAddr =
1787 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
1788 const pint_t lsdaArrayEndAddr =
1789 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
1790 if (log)
1791 fprintf(stderr, "\tfirst level search for result index=%d "
1792 "to secondLevelAddr=0x%llX\n",
1793 low, (uint64_t) secondLevelAddr);
1794 // do a binary search of second level page index
1795 uint32_t encoding = 0;
1796 pint_t funcStart = 0;
1797 pint_t funcEnd = 0;
1798 pint_t lsda = 0;
1799 pint_t personality = 0;
1800 uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
1801 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
1802 // regular page
1803 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
1804 secondLevelAddr);
1805 UnwindSectionRegularArray<A> pageIndex(
1806 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1807 // binary search looks for entry with e where index[e].offset <= pc <
1808 // index[e+1].offset
1809 if (log)
1810 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
1811 "regular page starting at secondLevelAddr=0x%llX\n",
1812 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
1813 low = 0;
1814 high = pageHeader.entryCount();
1815 while (low < high) {
1816 uint32_t mid = (low + high) / 2;
1817 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
1818 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
1819 // at end of table
1820 low = mid;
1821 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1822 break;
1823 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
1824 // next is too big, so we found it
1825 low = mid;
1826 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
1827 break;
1828 } else {
1829 low = mid + 1;
1830 }
1831 } else {
1832 high = mid;
1833 }
1834 }
1835 encoding = pageIndex.encoding(low);
1836 funcStart = pageIndex.functionOffset(low) + sects.dso_base;
1837 if (pc < funcStart) {
1838 if (log)
1839 fprintf(
1840 stderr,
1841 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1842 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1843 return false;
1844 }
1845 if (pc > funcEnd) {
1846 if (log)
1847 fprintf(
1848 stderr,
1849 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1850 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1851 return false;
1852 }
1853 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
1854 // compressed page
1855 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
1856 secondLevelAddr);
1857 UnwindSectionCompressedArray<A> pageIndex(
1858 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1859 const uint32_t targetFunctionPageOffset =
1860 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
1861 // binary search looks for entry with e where index[e].offset <= pc <
1862 // index[e+1].offset
1863 if (log)
1864 fprintf(stderr, "\tbinary search of compressed page starting at "
1865 "secondLevelAddr=0x%llX\n",
1866 (uint64_t) secondLevelAddr);
1867 low = 0;
1868 last = pageHeader.entryCount() - 1;
1869 high = pageHeader.entryCount();
1870 while (low < high) {
1871 uint32_t mid = (low + high) / 2;
1872 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
1873 if ((mid == last) ||
1874 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
1875 low = mid;
1876 break;
1877 } else {
1878 low = mid + 1;
1879 }
1880 } else {
1881 high = mid;
1882 }
1883 }
1884 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
1885 + sects.dso_base;
1886 if (low < last)
1887 funcEnd =
1888 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
1889 + sects.dso_base;
1890 else
1891 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1892 if (pc < funcStart) {
1893 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1894 "not in second level compressed unwind table. "
1895 "funcStart=0x%llX",
1896 (uint64_t) pc, (uint64_t) funcStart);
1897 return false;
1898 }
1899 if (pc > funcEnd) {
1900 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1901 "not in second level compressed unwind table. "
1902 "funcEnd=0x%llX",
1903 (uint64_t) pc, (uint64_t) funcEnd);
1904 return false;
1905 }
1906 uint16_t encodingIndex = pageIndex.encodingIndex(low);
1907 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
1908 // encoding is in common table in section header
1909 encoding = _addressSpace.get32(
1910 sects.compact_unwind_section +
1911 sectionHeader.commonEncodingsArraySectionOffset() +
1912 encodingIndex * sizeof(uint32_t));
1913 } else {
1914 // encoding is in page specific table
1915 uint16_t pageEncodingIndex =
1916 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
1917 encoding = _addressSpace.get32(secondLevelAddr +
1918 pageHeader.encodingsPageOffset() +
1919 pageEncodingIndex * sizeof(uint32_t));
1920 }
1921 } else {
1922 _LIBUNWIND_DEBUG_LOG(
1923 "malformed __unwind_info at 0x%0llX bad second level page",
1924 (uint64_t)sects.compact_unwind_section);
1925 return false;
1926 }
1927
1928 // look up LSDA, if encoding says function has one
1929 if (encoding & UNWIND_HAS_LSDA) {
1930 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
1931 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
1932 low = 0;
1933 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
1934 sizeof(unwind_info_section_header_lsda_index_entry);
1935 // binary search looks for entry with exact match for functionOffset
1936 if (log)
1937 fprintf(stderr,
1938 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
1939 funcStartOffset);
1940 while (low < high) {
1941 uint32_t mid = (low + high) / 2;
1942 if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
1943 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
1944 break;
1945 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
1946 low = mid + 1;
1947 } else {
1948 high = mid;
1949 }
1950 }
1951 if (lsda == 0) {
1952 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
1953 "pc=0x%0llX, but lsda table has no entry",
1954 encoding, (uint64_t) pc);
1955 return false;
1956 }
1957 }
1958
1959 // extract personality routine, if encoding says function has one
1960 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
1961 (__builtin_ctz(UNWIND_PERSONALITY_MASK));
1962 if (personalityIndex != 0) {
1963 --personalityIndex; // change 1-based to zero-based index
1964 if (personalityIndex >= sectionHeader.personalityArrayCount()) {
1965 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
1966 "but personality table has only %d entries",
1967 encoding, personalityIndex,
1968 sectionHeader.personalityArrayCount());
1969 return false;
1970 }
1971 int32_t personalityDelta = (int32_t)_addressSpace.get32(
1972 sects.compact_unwind_section +
1973 sectionHeader.personalityArraySectionOffset() +
1974 personalityIndex * sizeof(uint32_t));
1975 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
1976 personality = _addressSpace.getP(personalityPointer);
1977 if (log)
1978 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1979 "personalityDelta=0x%08X, personality=0x%08llX\n",
1980 (uint64_t) pc, personalityDelta, (uint64_t) personality);
1981 }
1982
1983 if (log)
1984 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1985 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
1986 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
1987 _info.start_ip = funcStart;
1988 _info.end_ip = funcEnd;
1989 _info.lsda = lsda;
1990 _info.handler = personality;
1991 _info.gp = 0;
1992 _info.flags = 0;
1993 _info.format = encoding;
1994 _info.unwind_info = 0;
1995 _info.unwind_info_size = 0;
1996 _info.extra = sects.dso_base;
1997 return true;
1998}
1999#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2000
2001
2002#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2003template <typename A, typename R>
2004bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
2005 pint_t base;
2006 RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
2007 if (!unwindEntry) {
2008 _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
2009 return false;
2010 }
2011 _info.gp = 0;
2012 _info.flags = 0;
2013 _info.format = 0;
2014 _info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
2015 _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
2016 _info.extra = base;
2017 _info.start_ip = base + unwindEntry->BeginAddress;
2018#ifdef _LIBUNWIND_TARGET_X86_64
2019 _info.end_ip = base + unwindEntry->EndAddress;
2020 // Only fill in the handler and LSDA if they're stale.
2021 if (pc != getLastPC()) {
2022 UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
2023 if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
2024 // The personality is given in the UNWIND_INFO itself. The LSDA immediately
2025 // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
2026 // these structures.)
2027 // N.B. UNWIND_INFO structs are DWORD-aligned.
2028 uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
2029 const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
2030 _info.lsda = reinterpret_cast<unw_word_t>(handler+1);
2031 _dispContext.HandlerData = reinterpret_cast<void *>(_info.lsda);
2032 _dispContext.LanguageHandler =
2033 reinterpret_cast<EXCEPTION_ROUTINE *>(base + *handler);
2034 if (*handler) {
2035 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2036 } else
2037 _info.handler = 0;
2038 } else {
2039 _info.lsda = 0;
2040 _info.handler = 0;
2041 }
2042 }
2043#elif defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_ARM)
2044
2045#if defined(_LIBUNWIND_TARGET_AARCH64)
2046#define FUNC_LENGTH_UNIT 4
2047#define XDATA_TYPE IMAGE_ARM64_RUNTIME_FUNCTION_ENTRY_XDATA
2048#else
2049#define FUNC_LENGTH_UNIT 2
2050#define XDATA_TYPE UNWIND_INFO_ARM
2051#endif
2052 if (unwindEntry->Flag != 0) { // Packed unwind info
2053 _info.end_ip =
2054 _info.start_ip + unwindEntry->FunctionLength * FUNC_LENGTH_UNIT;
2055 // Only fill in the handler and LSDA if they're stale.
2056 if (pc != getLastPC()) {
2057 // Packed unwind info doesn't have an exception handler.
2058 _info.lsda = 0;
2059 _info.handler = 0;
2060 }
2061 } else {
2062 XDATA_TYPE *xdata =
2063 reinterpret_cast<XDATA_TYPE *>(base + unwindEntry->UnwindData);
2064 _info.end_ip = _info.start_ip + xdata->FunctionLength * FUNC_LENGTH_UNIT;
2065 // Only fill in the handler and LSDA if they're stale.
2066 if (pc != getLastPC()) {
2067 if (xdata->ExceptionDataPresent) {
2068 uint32_t offset = 1; // The main xdata
2069 uint32_t codeWords = xdata->CodeWords;
2070 uint32_t epilogScopes = xdata->EpilogCount;
2071 if (xdata->EpilogCount == 0 && xdata->CodeWords == 0) {
2072 // The extension word has got the same layout for both ARM and ARM64
2073 uint32_t extensionWord = reinterpret_cast<uint32_t *>(xdata)[1];
2074 codeWords = (extensionWord >> 16) & 0xff;
2075 epilogScopes = extensionWord & 0xffff;
2076 offset++;
2077 }
2078 if (!xdata->EpilogInHeader)
2079 offset += epilogScopes;
2080 offset += codeWords;
2081 uint32_t *exceptionHandlerInfo =
2082 reinterpret_cast<uint32_t *>(xdata) + offset;
2083 _dispContext.HandlerData = &exceptionHandlerInfo[1];
2084 _dispContext.LanguageHandler = reinterpret_cast<EXCEPTION_ROUTINE *>(
2085 base + exceptionHandlerInfo[0]);
2086 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
2087 if (exceptionHandlerInfo[0])
2088 _info.handler =
2089 reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
2090 else
2091 _info.handler = 0;
2092 } else {
2093 _info.lsda = 0;
2094 _info.handler = 0;
2095 }
2096 }
2097 }
2098#endif
2099 setLastPC(pc);
2100 return true;
2101}
2102#endif
2103
2104#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2105// Masks for traceback table field xtbtable.
2106enum xTBTableMask : uint8_t {
2107 reservedBit = 0x02, // The traceback table was incorrectly generated if set
2108 // (see comments in function getInfoFromTBTable().
2109 ehInfoBit = 0x08 // Exception handling info is present if set
2110};
2111
2112enum frameType : unw_word_t {
2113 frameWithXLEHStateTable = 0,
2114 frameWithEHInfo = 1
2115};
2116
2117extern "C" {
2118typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
2119 uint64_t,
2120 _Unwind_Exception *,
2121 struct _Unwind_Context *);
2122}
2123
2124static __xlcxx_personality_v0_t *xlcPersonalityV0;
2125static RWMutex xlcPersonalityV0InitLock;
2126
2127template <typename A, typename R>
2128bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R &registers) {
2129 uint32_t *p = reinterpret_cast<uint32_t *>(pc);
2130
2131 // Keep looking forward until a word of 0 is found. The traceback
2132 // table starts at the following word.
2133 while (*p)
2134 ++p;
2135 tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
2136
2137 if (_LIBUNWIND_TRACING_UNWINDING) {
2138 char functionBuf[512];
2139 const char *functionName = functionBuf;
2140 unw_word_t offset;
2141 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2142 functionName = ".anonymous.";
2143 }
2144 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2145 __func__, functionName,
2146 reinterpret_cast<void *>(TBTable));
2147 }
2148
2149 // If the traceback table does not contain necessary info, bypass this frame.
2150 if (!TBTable->tb.has_tboff)
2151 return false;
2152
2153 // Structure tbtable_ext contains important data we are looking for.
2154 p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2155
2156 // Skip field parminfo if it exists.
2157 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2158 ++p;
2159
2160 // p now points to tb_offset, the offset from start of function to TB table.
2161 unw_word_t start_ip =
2162 reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
2163 unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
2164 ++p;
2165
2166 _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
2167 reinterpret_cast<void *>(start_ip),
2168 reinterpret_cast<void *>(end_ip));
2169
2170 // Skip field hand_mask if it exists.
2171 if (TBTable->tb.int_hndl)
2172 ++p;
2173
2174 unw_word_t lsda = 0;
2175 unw_word_t handler = 0;
2176 unw_word_t flags = frameType::frameWithXLEHStateTable;
2177
2178 if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
2179 // State table info is available. The ctl_info field indicates the
2180 // number of CTL anchors. There should be only one entry for the C++
2181 // state table.
2182 assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
2183 ++p;
2184 // p points to the offset of the state table into the stack.
2185 pint_t stateTableOffset = *p++;
2186
2187 int framePointerReg;
2188
2189 // Skip fields name_len and name if exist.
2190 if (TBTable->tb.name_present) {
2191 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
2192 p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
2193 sizeof(uint16_t));
2194 }
2195
2196 if (TBTable->tb.uses_alloca)
2197 framePointerReg = *(reinterpret_cast<char *>(p));
2198 else
2199 framePointerReg = 1; // default frame pointer == SP
2200
2201 _LIBUNWIND_TRACE_UNWINDING(
2202 "framePointerReg=%d, framePointer=%p, "
2203 "stateTableOffset=%#lx\n",
2204 framePointerReg,
2205 reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
2206 stateTableOffset);
2207 lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
2208
2209 // Since the traceback table generated by the legacy XLC++ does not
2210 // provide the location of the personality for the state table,
2211 // function __xlcxx_personality_v0(), which is the personality for the state
2212 // table and is exported from libc++abi, is directly assigned as the
2213 // handler here. When a legacy XLC++ frame is encountered, the symbol
2214 // is resolved dynamically using dlopen() to avoid a hard dependency of
2215 // libunwind on libc++abi in cases such as non-C++ applications.
2216
2217 // Resolve the function pointer to the state table personality if it has
2218 // not already been done.
2219 if (xlcPersonalityV0 == NULL) {
2220 xlcPersonalityV0InitLock.lock();
2221 if (xlcPersonalityV0 == NULL) {
2222 // Resolve __xlcxx_personality_v0 using dlopen().
2223 const char *libcxxabi = "libc++abi.a(libc++abi.so.1)";
2224 void *libHandle;
2225 // The AIX dlopen() sets errno to 0 when it is successful, which
2226 // clobbers the value of errno from the user code. This is an AIX
2227 // bug because according to POSIX it should not set errno to 0. To
2228 // workaround before AIX fixes the bug, errno is saved and restored.
2229 int saveErrno = errno;
2230 libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
2231 if (libHandle == NULL) {
2232 _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n", errno);
2233 assert(0 && "dlopen() failed");
2234 }
2235 xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
2236 dlsym(libHandle, "__xlcxx_personality_v0"));
2237 if (xlcPersonalityV0 == NULL) {
2238 _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
2239 dlclose(libHandle);
2240 assert(0 && "dlsym() failed");
2241 }
2242 errno = saveErrno;
2243 }
2244 xlcPersonalityV0InitLock.unlock();
2245 }
2246 handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
2247 _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
2248 reinterpret_cast<void *>(lsda),
2249 reinterpret_cast<void *>(handler));
2250 } else if (TBTable->tb.longtbtable) {
2251 // This frame has the traceback table extension. Possible cases are
2252 // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
2253 // is not EH aware; or, 3) a frame of other languages. We need to figure out
2254 // if the traceback table extension contains the 'eh_info' structure.
2255 //
2256 // We also need to deal with the complexity arising from some XL compiler
2257 // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
2258 // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
2259 // versa. For frames of code generated by those compilers, the 'longtbtable'
2260 // bit may be set but there isn't really a traceback table extension.
2261 //
2262 // In </usr/include/sys/debug.h>, there is the following definition of
2263 // 'struct tbtable_ext'. It is not really a structure but a dummy to
2264 // collect the description of optional parts of the traceback table.
2265 //
2266 // struct tbtable_ext {
2267 // ...
2268 // char alloca_reg; /* Register for alloca automatic storage */
2269 // struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
2270 // unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
2271 // };
2272 //
2273 // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
2274 // following 'alloca_reg' can be treated either as 'struct vec_ext' or
2275 // 'unsigned char xtbtable'. 'xtbtable' bits are defined in
2276 // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
2277 // unused and should not be set. 'struct vec_ext' is defined in
2278 // </usr/include/sys/debug.h> as follows:
2279 //
2280 // struct vec_ext {
2281 // unsigned vr_saved:6; /* Number of non-volatile vector regs saved
2282 // */
2283 // /* first register saved is assumed to be */
2284 // /* 32 - vr_saved */
2285 // unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */
2286 // unsigned has_varargs:1;
2287 // ...
2288 // };
2289 //
2290 // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
2291 // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
2292 // we checks if the 7th bit is set or not because 'xtbtable' should
2293 // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
2294 // in the future to make sure the mitigation works. This mitigation
2295 // is not 100% bullet proof because 'struct vec_ext' may not always have
2296 // 'saves_vrsave' bit set.
2297 //
2298 // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
2299 // checking the 7th bit.
2300
2301 // p points to field name len.
2302 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2303
2304 // Skip fields name_len and name if they exist.
2305 if (TBTable->tb.name_present) {
2306 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2307 charPtr = charPtr + name_len + sizeof(uint16_t);
2308 }
2309
2310 // Skip field alloc_reg if it exists.
2311 if (TBTable->tb.uses_alloca)
2312 ++charPtr;
2313
2314 // Check traceback table bit has_vec. Skip struct vec_ext if it exists.
2315 if (TBTable->tb.has_vec)
2316 // Note struct vec_ext does exist at this point because whether the
2317 // ordering of longtbtable and has_vec bits is correct or not, both
2318 // are set.
2319 charPtr += sizeof(struct vec_ext);
2320
2321 // charPtr points to field 'xtbtable'. Check if the EH info is available.
2322 // Also check if the reserved bit of the extended traceback table field
2323 // 'xtbtable' is set. If it is, the traceback table was incorrectly
2324 // generated by an XL compiler that uses the wrong ordering of 'longtbtable'
2325 // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
2326 // frame.
2327 if ((*charPtr & xTBTableMask::ehInfoBit) &&
2328 !(*charPtr & xTBTableMask::reservedBit)) {
2329 // Mark this frame has the new EH info.
2330 flags = frameType::frameWithEHInfo;
2331
2332 // eh_info is available.
2333 charPtr++;
2334 // The pointer is 4-byte aligned.
2335 if (reinterpret_cast<uintptr_t>(charPtr) % 4)
2336 charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
2337 uintptr_t *ehInfo =
2338 reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
2339 registers.getRegister(2) +
2340 *(reinterpret_cast<uintptr_t *>(charPtr)))));
2341
2342 // ehInfo points to structure en_info. The first member is version.
2343 // Only version 0 is currently supported.
2344 assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
2345 "libunwind: ehInfo version other than 0 is not supported");
2346
2347 // Increment ehInfo to point to member lsda.
2348 ++ehInfo;
2349 lsda = *ehInfo++;
2350
2351 // enInfo now points to member personality.
2352 handler = *ehInfo;
2353
2354 _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
2355 lsda, handler);
2356 }
2357 }
2358
2359 _info.start_ip = start_ip;
2360 _info.end_ip = end_ip;
2361 _info.lsda = lsda;
2362 _info.handler = handler;
2363 _info.gp = 0;
2364 _info.flags = flags;
2365 _info.format = 0;
2366 _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
2367 _info.unwind_info_size = 0;
2368 _info.extra = registers.getRegister(2);
2369
2370 return true;
2371}
2372
2373// Step back up the stack following the frame back link.
2374template <typename A, typename R>
2375int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
2376 R &registers, bool &isSignalFrame) {
2377 if (_LIBUNWIND_TRACING_UNWINDING) {
2378 char functionBuf[512];
2379 const char *functionName = functionBuf;
2380 unw_word_t offset;
2381 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2382 functionName = ".anonymous.";
2383 }
2384 _LIBUNWIND_TRACE_UNWINDING(
2385 "%s: Look up traceback table of func=%s at %p, pc=%p, "
2386 "SP=%p, saves_lr=%d, stores_bc=%d",
2387 __func__, functionName, reinterpret_cast<void *>(TBTable),
2388 reinterpret_cast<void *>(pc),
2389 reinterpret_cast<void *>(registers.getSP()), TBTable->tb.saves_lr,
2390 TBTable->tb.stores_bc);
2391 }
2392
2393#if defined(__powerpc64__)
2394 // Instruction to reload TOC register "ld r2,40(r1)"
2395 const uint32_t loadTOCRegInst = 0xe8410028;
2396 const int32_t unwPPCF0Index = UNW_PPC64_F0;
2397 const int32_t unwPPCV0Index = UNW_PPC64_V0;
2398#else
2399 // Instruction to reload TOC register "lwz r2,20(r1)"
2400 const uint32_t loadTOCRegInst = 0x80410014;
2401 const int32_t unwPPCF0Index = UNW_PPC_F0;
2402 const int32_t unwPPCV0Index = UNW_PPC_V0;
2403#endif
2404
2405 // lastStack points to the stack frame of the next routine up.
2406 pint_t curStack = static_cast<pint_t>(registers.getSP());
2407 pint_t lastStack = *reinterpret_cast<pint_t *>(curStack);
2408
2409 if (lastStack == 0)
2410 return UNW_STEP_END;
2411
2412 R newRegisters = registers;
2413
2414 // If backchain is not stored, use the current stack frame.
2415 if (!TBTable->tb.stores_bc)
2416 lastStack = curStack;
2417
2418 // Return address is the address after call site instruction.
2419 pint_t returnAddress;
2420
2421 if (isSignalFrame) {
2422 _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
2423 reinterpret_cast<void *>(lastStack));
2424
2425 sigcontext *sigContext = reinterpret_cast<sigcontext *>(
2426 reinterpret_cast<char *>(lastStack) + STKMINALIGN);
2427 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2428
2429 bool useSTKMIN = false;
2430 if (returnAddress < 0x10000000) {
2431 // Try again using STKMIN.
2432 sigContext = reinterpret_cast<sigcontext *>(
2433 reinterpret_cast<char *>(lastStack) + STKMIN);
2434 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2435 if (returnAddress < 0x10000000) {
2436 _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p from sigcontext=%p",
2437 reinterpret_cast<void *>(returnAddress),
2438 reinterpret_cast<void *>(sigContext));
2439 return UNW_EBADFRAME;
2440 }
2441 useSTKMIN = true;
2442 }
2443 _LIBUNWIND_TRACE_UNWINDING("Returning from a signal handler %s: "
2444 "sigContext=%p, returnAddress=%p. "
2445 "Seems to be a valid address",
2446 useSTKMIN ? "STKMIN" : "STKMINALIGN",
2447 reinterpret_cast<void *>(sigContext),
2448 reinterpret_cast<void *>(returnAddress));
2449
2450 // Restore the condition register from sigcontext.
2451 newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
2452
2453 // Save the LR in sigcontext for stepping up when the function that
2454 // raised the signal is a leaf function. This LR has the return address
2455 // to the caller of the leaf function.
2456 newRegisters.setLR(sigContext->sc_jmpbuf.jmp_context.lr);
2457 _LIBUNWIND_TRACE_UNWINDING(
2458 "Save LR=%p from sigcontext",
2459 reinterpret_cast<void *>(sigContext->sc_jmpbuf.jmp_context.lr));
2460
2461 // Restore GPRs from sigcontext.
2462 for (int i = 0; i < 32; ++i)
2463 newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
2464
2465 // Restore FPRs from sigcontext.
2466 for (int i = 0; i < 32; ++i)
2467 newRegisters.setFloatRegister(i + unwPPCF0Index,
2468 sigContext->sc_jmpbuf.jmp_context.fpr[i]);
2469
2470 // Restore vector registers if there is an associated extended context
2471 // structure.
2472 if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
2473 ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
2474 if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
2475 for (int i = 0; i < 32; ++i)
2476 newRegisters.setVectorRegister(
2477 i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
2478 &(uContext->__extctx->__vmx.__vr[i]))));
2479 }
2480 }
2481 } else {
2482 // Step up a normal frame.
2483
2484 if (!TBTable->tb.saves_lr && registers.getLR()) {
2485 // This case should only occur if we were called from a signal handler
2486 // and the signal occurred in a function that doesn't save the LR.
2487 returnAddress = static_cast<pint_t>(registers.getLR());
2488 _LIBUNWIND_TRACE_UNWINDING("Use saved LR=%p",
2489 reinterpret_cast<void *>(returnAddress));
2490 } else {
2491 // Otherwise, use the LR value in the stack link area.
2492 returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
2493 }
2494
2495 // Reset LR in the current context.
2496 newRegisters.setLR(static_cast<uintptr_t>(NULL));
2497
2498 _LIBUNWIND_TRACE_UNWINDING(
2499 "Extract info from lastStack=%p, returnAddress=%p",
2500 reinterpret_cast<void *>(lastStack),
2501 reinterpret_cast<void *>(returnAddress));
2502 _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d",
2503 TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
2504 TBTable->tb.saves_cr);
2505
2506 // Restore FP registers.
2507 char *ptrToRegs = reinterpret_cast<char *>(lastStack);
2508 double *FPRegs = reinterpret_cast<double *>(
2509 ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
2510 for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
2511 newRegisters.setFloatRegister(
2512 32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
2513
2514 // Restore GP registers.
2515 ptrToRegs = reinterpret_cast<char *>(FPRegs);
2516 uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
2517 ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
2518 for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
2519 newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
2520
2521 // Restore Vector registers.
2522 ptrToRegs = reinterpret_cast<char *>(GPRegs);
2523
2524 // Restore vector registers only if this is a Clang frame. Also
2525 // check if traceback table bit has_vec is set. If it is, structure
2526 // vec_ext is available.
2527 if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
2528
2529 // Get to the vec_ext structure to check if vector registers are saved.
2530 uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2531
2532 // Skip field parminfo if exists.
2533 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2534 ++p;
2535
2536 // Skip field tb_offset if exists.
2537 if (TBTable->tb.has_tboff)
2538 ++p;
2539
2540 // Skip field hand_mask if exists.
2541 if (TBTable->tb.int_hndl)
2542 ++p;
2543
2544 // Skip fields ctl_info and ctl_info_disp if exist.
2545 if (TBTable->tb.has_ctl) {
2546 // Skip field ctl_info.
2547 ++p;
2548 // Skip field ctl_info_disp.
2549 ++p;
2550 }
2551
2552 // Skip fields name_len and name if exist.
2553 // p is supposed to point to field name_len now.
2554 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2555 if (TBTable->tb.name_present) {
2556 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2557 charPtr = charPtr + name_len + sizeof(uint16_t);
2558 }
2559
2560 // Skip field alloc_reg if it exists.
2561 if (TBTable->tb.uses_alloca)
2562 ++charPtr;
2563
2564 struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
2565
2566 _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d", vec_ext->vr_saved);
2567
2568 // Restore vector register(s) if saved on the stack.
2569 if (vec_ext->vr_saved) {
2570 // Saved vector registers are 16-byte aligned.
2571 if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
2572 ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
2573 v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
2574 sizeof(v128));
2575 for (int i = 0; i < vec_ext->vr_saved; ++i) {
2576 newRegisters.setVectorRegister(
2577 32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
2578 }
2579 }
2580 }
2581 if (TBTable->tb.saves_cr) {
2582 // Get the saved condition register. The condition register is only
2583 // a single word.
2584 newRegisters.setCR(
2585 *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
2586 }
2587
2588 // Restore the SP.
2589 newRegisters.setSP(lastStack);
2590
2591 // The first instruction after return.
2592 uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
2593
2594 // Do we need to set the TOC register?
2595 _LIBUNWIND_TRACE_UNWINDING(
2596 "Current gpr2=%p",
2597 reinterpret_cast<void *>(newRegisters.getRegister(2)));
2598 if (firstInstruction == loadTOCRegInst) {
2599 _LIBUNWIND_TRACE_UNWINDING(
2600 "Set gpr2=%p from frame",
2601 reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
2602 newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
2603 }
2604 }
2605 _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
2606 reinterpret_cast<void *>(lastStack),
2607 reinterpret_cast<void *>(returnAddress),
2608 reinterpret_cast<void *>(pc));
2609
2610 // The return address is the address after call site instruction, so
2611 // setting IP to that simulates a return.
2612 newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
2613
2614 // Simulate the step by replacing the register set with the new ones.
2615 registers = newRegisters;
2616
2617 // Check if the next frame is a signal frame.
2618 pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2619
2620 // Return address is the address after call site instruction.
2621 pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
2622
2623 if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
2624 _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
2625 "nextStack=%p, next return address=%p\n",
2626 reinterpret_cast<void *>(nextStack),
2627 reinterpret_cast<void *>(nextReturnAddress));
2628 isSignalFrame = true;
2629 } else {
2630 isSignalFrame = false;
2631 }
2632 return UNW_STEP_SUCCESS;
2633}
2634#endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2635
2636template <typename A, typename R>
2637void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
2638#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
2639 defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
2640 _isSigReturn = false;
2641#endif
2642
2643 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2644#if defined(_LIBUNWIND_ARM_EHABI)
2645 // Remove the thumb bit so the IP represents the actual instruction address.
2646 // This matches the behaviour of _Unwind_GetIP on arm.
2647 pc &= (pint_t)~0x1;
2648#endif
2649
2650 // Exit early if at the top of the stack.
2651 if (pc == 0) {
2652 _unwindInfoMissing = true;
2653 return;
2654 }
2655
2656 // If the last line of a function is a "throw" the compiler sometimes
2657 // emits no instructions after the call to __cxa_throw. This means
2658 // the return address is actually the start of the next function.
2659 // To disambiguate this, back up the pc when we know it is a return
2660 // address.
2661 if (isReturnAddress)
2662#if defined(_AIX)
2663 // PC needs to be a 4-byte aligned address to be able to look for a
2664 // word of 0 that indicates the start of the traceback table at the end
2665 // of a function on AIX.
2666 pc -= 4;
2667#else
2668 --pc;
2669#endif
2670
2671#if !(defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)) && \
2672 !defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2673 // In case of this is frame of signal handler, the IP saved in the signal
2674 // handler points to first non-executed instruction, while FDE/CIE expects IP
2675 // to be after the first non-executed instruction.
2676 if (_isSignalFrame)
2677 ++pc;
2678#endif
2679
2680 // Ask address space object to find unwind sections for this pc.
2681 UnwindInfoSections sects;
2682 if (_addressSpace.findUnwindSections(pc, sects)) {
2683#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2684 // If there is a compact unwind encoding table, look there first.
2685 if (sects.compact_unwind_section != 0) {
2686 if (this->getInfoFromCompactEncodingSection(pc, sects)) {
2687 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2688 // Found info in table, done unless encoding says to use dwarf.
2689 uint32_t dwarfOffset;
2690 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
2691 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
2692 // found info in dwarf, done
2693 return;
2694 }
2695 }
2696 #endif
2697 // If unwind table has entry, but entry says there is no unwind info,
2698 // record that we have no unwind info.
2699 if (_info.format == 0)
2700 _unwindInfoMissing = true;
2701 return;
2702 }
2703 }
2704#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2705
2706#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2707 // If there is SEH unwind info, look there next.
2708 if (this->getInfoFromSEH(pc))
2709 return;
2710#endif
2711
2712#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2713 // If there is unwind info in the traceback table, look there next.
2714 if (this->getInfoFromTBTable(pc, _registers))
2715 return;
2716#endif
2717
2718#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2719 // If there is dwarf unwind info, look there next.
2720 if (sects.dwarf_section != 0) {
2721 if (this->getInfoFromDwarfSection(pc, sects)) {
2722 // found info in dwarf, done
2723 return;
2724 }
2725 }
2726#endif
2727
2728#if defined(_LIBUNWIND_ARM_EHABI)
2729 // If there is ARM EHABI unwind info, look there next.
2730 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
2731 return;
2732#endif
2733 }
2734
2735#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2736 // There is no static unwind info for this pc. Look to see if an FDE was
2737 // dynamically registered for it.
2738 pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
2739 pc);
2740 if (cachedFDE != 0) {
2741 typename CFI_Parser<A>::FDE_Info fdeInfo;
2742 typename CFI_Parser<A>::CIE_Info cieInfo;
2743 if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
2744 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, dso_base: 0))
2745 return;
2746 }
2747
2748 // Lastly, ask AddressSpace object about platform specific ways to locate
2749 // other FDEs.
2750 pint_t fde;
2751 if (_addressSpace.findOtherFDE(pc, fde)) {
2752 typename CFI_Parser<A>::FDE_Info fdeInfo;
2753 typename CFI_Parser<A>::CIE_Info cieInfo;
2754 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
2755 // Double check this FDE is for a function that includes the pc.
2756 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
2757 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, dso_base: 0))
2758 return;
2759 }
2760 }
2761#endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2762
2763#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
2764 defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
2765 if (setInfoForSigReturn())
2766 return;
2767#endif
2768
2769 // no unwind info, flag that we can't reliably unwind
2770 _unwindInfoMissing = true;
2771}
2772
2773#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2774 defined(_LIBUNWIND_TARGET_AARCH64)
2775template <typename A, typename R>
2776bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
2777 // Look for the sigreturn trampoline. The trampoline's body is two
2778 // specific instructions (see below). Typically the trampoline comes from the
2779 // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
2780 // own restorer function, though, or user-mode QEMU might write a trampoline
2781 // onto the stack.
2782 //
2783 // This special code path is a fallback that is only used if the trampoline
2784 // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
2785 // constant for the PC needs to be defined before DWARF can handle a signal
2786 // trampoline. This code may segfault if the target PC is unreadable, e.g.:
2787 // - The PC points at a function compiled without unwind info, and which is
2788 // part of an execute-only mapping (e.g. using -Wl,--execute-only).
2789 // - The PC is invalid and happens to point to unreadable or unmapped memory.
2790 //
2791 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
2792 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2793 // The PC might contain an invalid address if the unwind info is bad, so
2794 // directly accessing it could cause a SIGSEGV.
2795 if (!isReadableAddr(pc))
2796 return false;
2797 auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2798 // Look for instructions: mov x8, #0x8b; svc #0x0
2799 if (instructions[0] != 0xd2801168 || instructions[1] != 0xd4000001)
2800 return false;
2801
2802 _info = {};
2803 _info.start_ip = pc;
2804 _info.end_ip = pc + 4;
2805 _isSigReturn = true;
2806 return true;
2807}
2808
2809template <typename A, typename R>
2810int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
2811 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2812 // - 128-byte siginfo struct
2813 // - ucontext struct:
2814 // - 8-byte long (uc_flags)
2815 // - 8-byte pointer (uc_link)
2816 // - 24-byte stack_t
2817 // - 128-byte signal set
2818 // - 8 bytes of padding because sigcontext has 16-byte alignment
2819 // - sigcontext/mcontext_t
2820 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
2821 const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
2822
2823 // Offsets from sigcontext to each register.
2824 const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
2825 const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
2826 const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
2827
2828 pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2829
2830 for (int i = 0; i <= 30; ++i) {
2831 uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
2832 static_cast<pint_t>(i * 8));
2833 _registers.setRegister(UNW_AARCH64_X0 + i, value);
2834 }
2835 _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
2836 _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
2837 _isSignalFrame = true;
2838 return UNW_STEP_SUCCESS;
2839}
2840#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2841 // defined(_LIBUNWIND_TARGET_AARCH64)
2842
2843#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2844 defined(_LIBUNWIND_TARGET_LOONGARCH)
2845template <typename A, typename R>
2846bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_loongarch &) {
2847 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2848 // The PC might contain an invalid address if the unwind info is bad, so
2849 // directly accessing it could cause a SIGSEGV.
2850 if (!isReadableAddr(pc))
2851 return false;
2852 const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2853 // Look for the two instructions used in the sigreturn trampoline
2854 // __vdso_rt_sigreturn:
2855 //
2856 // 0x03822c0b li a7,0x8b
2857 // 0x002b0000 syscall 0
2858 if (instructions[0] != 0x03822c0b || instructions[1] != 0x002b0000)
2859 return false;
2860
2861 _info = {};
2862 _info.start_ip = pc;
2863 _info.end_ip = pc + 4;
2864 _isSigReturn = true;
2865 return true;
2866}
2867
2868template <typename A, typename R>
2869int UnwindCursor<A, R>::stepThroughSigReturn(Registers_loongarch &) {
2870 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2871 // - 128-byte siginfo struct
2872 // - ucontext_t struct:
2873 // - 8-byte long (__uc_flags)
2874 // - 8-byte pointer (*uc_link)
2875 // - 24-byte uc_stack
2876 // - 8-byte uc_sigmask
2877 // - 120-byte of padding to allow sigset_t to be expanded in the future
2878 // - 8 bytes of padding because sigcontext has 16-byte alignment
2879 // - struct sigcontext uc_mcontext
2880 // [1]
2881 // https://github.com/torvalds/linux/blob/master/arch/loongarch/kernel/signal.c
2882 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2883
2884 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2885 _registers.setIP(_addressSpace.get64(sigctx));
2886 for (int i = UNW_LOONGARCH_R1; i <= UNW_LOONGARCH_R31; ++i) {
2887 // skip R0
2888 uint64_t value =
2889 _addressSpace.get64(sigctx + static_cast<pint_t>((i + 1) * 8));
2890 _registers.setRegister(i, value);
2891 }
2892 _isSignalFrame = true;
2893 return UNW_STEP_SUCCESS;
2894}
2895#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2896 // defined(_LIBUNWIND_TARGET_LOONGARCH)
2897
2898#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2899 defined(_LIBUNWIND_TARGET_RISCV)
2900template <typename A, typename R>
2901bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_riscv &) {
2902 const pint_t pc = static_cast<pint_t>(getReg(UNW_REG_IP));
2903 // The PC might contain an invalid address if the unwind info is bad, so
2904 // directly accessing it could cause a SIGSEGV.
2905 if (!isReadableAddr(pc))
2906 return false;
2907 const auto *instructions = reinterpret_cast<const uint32_t *>(pc);
2908 // Look for the two instructions used in the sigreturn trampoline
2909 // __vdso_rt_sigreturn:
2910 //
2911 // 0x08b00893 li a7,0x8b
2912 // 0x00000073 ecall
2913 if (instructions[0] != 0x08b00893 || instructions[1] != 0x00000073)
2914 return false;
2915
2916 _info = {};
2917 _info.start_ip = pc;
2918 _info.end_ip = pc + 4;
2919 _isSigReturn = true;
2920 return true;
2921}
2922
2923template <typename A, typename R>
2924int UnwindCursor<A, R>::stepThroughSigReturn(Registers_riscv &) {
2925 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2926 // - 128-byte siginfo struct
2927 // - ucontext_t struct:
2928 // - 8-byte long (__uc_flags)
2929 // - 8-byte pointer (*uc_link)
2930 // - 24-byte uc_stack
2931 // - 8-byte uc_sigmask
2932 // - 120-byte of padding to allow sigset_t to be expanded in the future
2933 // - 8 bytes of padding because sigcontext has 16-byte alignment
2934 // - struct sigcontext uc_mcontext
2935 // [1]
2936 // https://github.com/torvalds/linux/blob/master/arch/riscv/kernel/signal.c
2937 const pint_t kOffsetSpToSigcontext = 128 + 8 + 8 + 24 + 8 + 128;
2938
2939 const pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2940 _registers.setIP(_addressSpace.get64(sigctx));
2941 for (int i = UNW_RISCV_X1; i <= UNW_RISCV_X31; ++i) {
2942 uint64_t value = _addressSpace.get64(sigctx + static_cast<pint_t>(i * 8));
2943 _registers.setRegister(i, value);
2944 }
2945 _isSignalFrame = true;
2946 return UNW_STEP_SUCCESS;
2947}
2948#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2949 // defined(_LIBUNWIND_TARGET_RISCV)
2950
2951#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2952 defined(_LIBUNWIND_TARGET_S390X)
2953template <typename A, typename R>
2954bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
2955 // Look for the sigreturn trampoline. The trampoline's body is a
2956 // specific instruction (see below). Typically the trampoline comes from the
2957 // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its
2958 // own restorer function, though, or user-mode QEMU might write a trampoline
2959 // onto the stack.
2960 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2961 // The PC might contain an invalid address if the unwind info is bad, so
2962 // directly accessing it could cause a SIGSEGV.
2963 if (!isReadableAddr(pc))
2964 return false;
2965 const auto inst = *reinterpret_cast<const uint16_t *>(pc);
2966 if (inst == 0x0a77 || inst == 0x0aad) {
2967 _info = {};
2968 _info.start_ip = pc;
2969 _info.end_ip = pc + 2;
2970 _isSigReturn = true;
2971 return true;
2972 }
2973 return false;
2974}
2975
2976template <typename A, typename R>
2977int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
2978 // Determine current SP.
2979 const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP));
2980 // According to the s390x ABI, the CFA is at (incoming) SP + 160.
2981 const pint_t cfa = sp + 160;
2982
2983 // Determine current PC and instruction there (this must be either
2984 // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn").
2985 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2986 const uint16_t inst = _addressSpace.get16(pc);
2987
2988 // Find the addresses of the signo and sigcontext in the frame.
2989 pint_t pSigctx = 0;
2990 pint_t pSigno = 0;
2991
2992 // "svc __NR_sigreturn" uses a non-RT signal trampoline frame.
2993 if (inst == 0x0a77) {
2994 // Layout of a non-RT signal trampoline frame, starting at the CFA:
2995 // - 8-byte signal mask
2996 // - 8-byte pointer to sigcontext, followed by signo
2997 // - 4-byte signo
2998 pSigctx = _addressSpace.get64(cfa + 8);
2999 pSigno = pSigctx + 344;
3000 }
3001
3002 // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame.
3003 if (inst == 0x0aad) {
3004 // Layout of a RT signal trampoline frame, starting at the CFA:
3005 // - 8-byte retcode (+ alignment)
3006 // - 128-byte siginfo struct (starts with signo)
3007 // - ucontext struct:
3008 // - 8-byte long (uc_flags)
3009 // - 8-byte pointer (uc_link)
3010 // - 24-byte stack_t
3011 // - 8 bytes of padding because sigcontext has 16-byte alignment
3012 // - sigcontext/mcontext_t
3013 pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8;
3014 pSigno = cfa + 8;
3015 }
3016
3017 assert(pSigctx != 0);
3018 assert(pSigno != 0);
3019
3020 // Offsets from sigcontext to each register.
3021 const pint_t kOffsetPc = 8;
3022 const pint_t kOffsetGprs = 16;
3023 const pint_t kOffsetFprs = 216;
3024
3025 // Restore all registers.
3026 for (int i = 0; i < 16; ++i) {
3027 uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs +
3028 static_cast<pint_t>(i * 8));
3029 _registers.setRegister(UNW_S390X_R0 + i, value);
3030 }
3031 for (int i = 0; i < 16; ++i) {
3032 static const int fpr[16] = {
3033 UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3,
3034 UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7,
3035 UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11,
3036 UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15
3037 };
3038 double value = _addressSpace.getDouble(pSigctx + kOffsetFprs +
3039 static_cast<pint_t>(i * 8));
3040 _registers.setFloatRegister(fpr[i], value);
3041 }
3042 _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc));
3043
3044 // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
3045 // after the faulting instruction rather than before it.
3046 // Do not set _isSignalFrame in that case.
3047 uint32_t signo = _addressSpace.get32(pSigno);
3048 _isSignalFrame = (signo != 4 && signo != 5 && signo != 8);
3049
3050 return UNW_STEP_SUCCESS;
3051}
3052#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
3053 // defined(_LIBUNWIND_TARGET_S390X)
3054
3055#if defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3056template <typename A, typename R>
3057bool UnwindCursor<A, R>::setInfoForSigReturn() {
3058 Dl_info dlinfo;
3059 const auto isSignalHandler = [&](pint_t addr) {
3060 if (!dladdr(reinterpret_cast<void *>(addr), &dlinfo))
3061 return false;
3062 if (strcmp(dlinfo.dli_fname, "commpage"))
3063 return false;
3064 if (dlinfo.dli_sname == NULL ||
3065 strcmp(dlinfo.dli_sname, "commpage_signal_handler"))
3066 return false;
3067 return true;
3068 };
3069
3070 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
3071 if (!isSignalHandler(pc))
3072 return false;
3073
3074 pint_t start = reinterpret_cast<pint_t>(dlinfo.dli_saddr);
3075
3076 static size_t signalHandlerSize = 0;
3077 if (signalHandlerSize == 0) {
3078 size_t boundLow = 0;
3079 size_t boundHigh = static_cast<size_t>(-1);
3080
3081 area_info areaInfo;
3082 if (get_area_info(area_for(dlinfo.dli_saddr), &areaInfo) == B_OK)
3083 boundHigh = areaInfo.size;
3084
3085 while (boundLow < boundHigh) {
3086 size_t boundMid = boundLow + ((boundHigh - boundLow) / 2);
3087 pint_t test = start + boundMid;
3088 if (test >= start && isSignalHandler(test))
3089 boundLow = boundMid + 1;
3090 else
3091 boundHigh = boundMid;
3092 }
3093
3094 signalHandlerSize = boundHigh;
3095 }
3096
3097 _info = {};
3098 _info.start_ip = start;
3099 _info.end_ip = start + signalHandlerSize;
3100 _isSigReturn = true;
3101
3102 return true;
3103}
3104
3105template <typename A, typename R>
3106int UnwindCursor<A, R>::stepThroughSigReturn() {
3107 _isSignalFrame = true;
3108
3109#if defined(_LIBUNWIND_TARGET_X86_64)
3110 // Layout of the stack before function call:
3111 // - signal_frame_data
3112 // + siginfo_t (public struct, fairly stable)
3113 // + ucontext_t (public struct, fairly stable)
3114 // - mcontext_t -> Offset 0x70, this is what we want.
3115 // - frame->ip (8 bytes)
3116 // - frame->bp (8 bytes). Not written by the kernel,
3117 // but the signal handler has a "push %rbp" instruction.
3118 pint_t bp = this->getReg(UNW_X86_64_RBP);
3119 vregs *regs = (vregs *)(bp + 0x70);
3120
3121 _registers.setRegister(UNW_REG_IP, regs->rip);
3122 _registers.setRegister(UNW_REG_SP, regs->rsp);
3123 _registers.setRegister(UNW_X86_64_RAX, regs->rax);
3124 _registers.setRegister(UNW_X86_64_RDX, regs->rdx);
3125 _registers.setRegister(UNW_X86_64_RCX, regs->rcx);
3126 _registers.setRegister(UNW_X86_64_RBX, regs->rbx);
3127 _registers.setRegister(UNW_X86_64_RSI, regs->rsi);
3128 _registers.setRegister(UNW_X86_64_RDI, regs->rdi);
3129 _registers.setRegister(UNW_X86_64_RBP, regs->rbp);
3130 _registers.setRegister(UNW_X86_64_R8, regs->r8);
3131 _registers.setRegister(UNW_X86_64_R9, regs->r9);
3132 _registers.setRegister(UNW_X86_64_R10, regs->r10);
3133 _registers.setRegister(UNW_X86_64_R11, regs->r11);
3134 _registers.setRegister(UNW_X86_64_R12, regs->r12);
3135 _registers.setRegister(UNW_X86_64_R13, regs->r13);
3136 _registers.setRegister(UNW_X86_64_R14, regs->r14);
3137 _registers.setRegister(UNW_X86_64_R15, regs->r15);
3138 // TODO: XMM
3139#endif // defined(_LIBUNWIND_TARGET_X86_64)
3140
3141 return UNW_STEP_SUCCESS;
3142}
3143#endif // defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3144
3145template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
3146 (void)stage2;
3147 // Bottom of stack is defined is when unwind info cannot be found.
3148 if (_unwindInfoMissing)
3149 return UNW_STEP_END;
3150
3151 // Use unwinding info to modify register set as if function returned.
3152 int result;
3153#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
3154 defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
3155 if (_isSigReturn) {
3156 result = this->stepThroughSigReturn();
3157 } else
3158#endif
3159 {
3160#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
3161 result = this->stepWithCompactEncoding(stage2);
3162#elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
3163 result = this->stepWithSEHData();
3164#elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
3165 result = this->stepWithTBTableData();
3166#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
3167 result = this->stepWithDwarfFDE(stage2);
3168#elif defined(_LIBUNWIND_ARM_EHABI)
3169 result = this->stepWithEHABI();
3170#else
3171 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
3172 _LIBUNWIND_SUPPORT_SEH_UNWIND or \
3173 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
3174 _LIBUNWIND_ARM_EHABI
3175#endif
3176 }
3177
3178 // update info based on new PC
3179 if (result == UNW_STEP_SUCCESS) {
3180 this->setInfoBasedOnIPRegister(true);
3181 if (_unwindInfoMissing)
3182 return UNW_STEP_END;
3183 }
3184
3185 return result;
3186}
3187
3188template <typename A, typename R>
3189void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
3190 if (_unwindInfoMissing)
3191 memset(s: info, c: 0, n: sizeof(*info));
3192 else
3193 *info = _info;
3194}
3195
3196template <typename A, typename R>
3197bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
3198 unw_word_t *offset) {
3199 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
3200 buf, bufLen, offset);
3201}
3202
3203#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
3204template <typename A, typename R>
3205bool UnwindCursor<A, R>::isReadableAddr(const pint_t addr) const {
3206 // We use SYS_rt_sigprocmask, inspired by Abseil's AddressIsReadable.
3207
3208 const auto sigsetAddr = reinterpret_cast<sigset_t *>(addr);
3209 // We have to check that addr is nullptr because sigprocmask allows that
3210 // as an argument without failure.
3211 if (!sigsetAddr)
3212 return false;
3213 const auto saveErrno = errno;
3214 // We MUST use a raw syscall here, as wrappers may try to access
3215 // sigsetAddr which may cause a SIGSEGV. A raw syscall however is
3216 // safe. Additionally, we need to pass the kernel_sigset_size, which is
3217 // different from libc sizeof(sigset_t). For the majority of architectures,
3218 // it's 64 bits (_NSIG), and libc NSIG is _NSIG + 1.
3219 const auto kernelSigsetSize = NSIG / 8;
3220 [[maybe_unused]] const int Result = syscall(
3221 SYS_rt_sigprocmask, /*how=*/~0, sigsetAddr, nullptr, kernelSigsetSize);
3222 // Because our "how" is invalid, this syscall should always fail, and our
3223 // errno should always be EINVAL or an EFAULT. This relies on the Linux
3224 // kernel to check copy_from_user before checking if the "how" argument is
3225 // invalid.
3226 assert(Result == -1);
3227 assert(errno == EFAULT || errno == EINVAL);
3228 const auto readable = errno != EFAULT;
3229 errno = saveErrno;
3230 return readable;
3231}
3232#endif
3233
3234#if defined(_LIBUNWIND_USE_CET) || defined(_LIBUNWIND_USE_GCS)
3235extern "C" void *__libunwind_shstk_get_registers(unw_cursor_t *cursor) {
3236 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
3237 return co->get_registers();
3238}
3239#endif
3240} // namespace libunwind
3241
3242#endif // __UNWINDCURSOR_HPP__
3243