1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //
8 // C++ interface to lower levels of libunwind
9 //===----------------------------------------------------------------------===//
10
11 #ifndef __UNWINDCURSOR_HPP__
12 #define __UNWINDCURSOR_HPP__
13
14 #include "cet_unwind.h"
15 #include <stdint.h>
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <unwind.h>
19
20 #ifdef _WIN32
21 #include <windows.h>
22 #include <ntverp.h>
23 #endif
24 #ifdef __APPLE__
25 #include <mach-o/dyld.h>
26 #endif
27 #ifdef _AIX
28 #include <dlfcn.h>
29 #include <sys/debug.h>
30 #include <sys/pseg.h>
31 #endif
32
33 #if defined(_LIBUNWIND_TARGET_LINUX) && \
34 (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X))
35 #include <sys/syscall.h>
36 #include <sys/uio.h>
37 #include <unistd.h>
38 #define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
39 #endif
40
41 #include "AddressSpace.hpp"
42 #include "CompactUnwinder.hpp"
43 #include "config.h"
44 #include "DwarfInstructions.hpp"
45 #include "EHHeaderParser.hpp"
46 #include "libunwind.h"
47 #include "libunwind_ext.h"
48 #include "Registers.hpp"
49 #include "RWMutex.hpp"
50 #include "Unwind-EHABI.h"
51
52 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
53 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
54 // earlier) SDKs.
55 // MinGW-w64 has always provided this struct.
56 #if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
57 !defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
58 struct _DISPATCHER_CONTEXT {
59 ULONG64 ControlPc;
60 ULONG64 ImageBase;
61 PRUNTIME_FUNCTION FunctionEntry;
62 ULONG64 EstablisherFrame;
63 ULONG64 TargetIp;
64 PCONTEXT ContextRecord;
65 PEXCEPTION_ROUTINE LanguageHandler;
66 PVOID HandlerData;
67 PUNWIND_HISTORY_TABLE HistoryTable;
68 ULONG ScopeIndex;
69 ULONG Fill0;
70 };
71 #endif
72
73 struct UNWIND_INFO {
74 uint8_t Version : 3;
75 uint8_t Flags : 5;
76 uint8_t SizeOfProlog;
77 uint8_t CountOfCodes;
78 uint8_t FrameRegister : 4;
79 uint8_t FrameOffset : 4;
80 uint16_t UnwindCodes[2];
81 };
82
83 extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
84 int, _Unwind_Action, uint64_t, _Unwind_Exception *,
85 struct _Unwind_Context *);
86
87 #endif
88
89 namespace libunwind {
90
91 static thread_local UnwindInfoSectionsCache uwis_cache;
92
93 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
94 /// Cache of recently found FDEs.
95 template <typename A>
96 class _LIBUNWIND_HIDDEN DwarfFDECache {
97 typedef typename A::pint_t pint_t;
98 public:
99 static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
100 static pint_t findFDE(pint_t mh, pint_t pc);
101 static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
102 static void removeAllIn(pint_t mh);
103 static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
104 unw_word_t ip_end,
105 unw_word_t fde, unw_word_t mh));
106
107 private:
108
109 struct entry {
110 pint_t mh;
111 pint_t ip_start;
112 pint_t ip_end;
113 pint_t fde;
114 };
115
116 // These fields are all static to avoid needing an initializer.
117 // There is only one instance of this class per process.
118 static RWMutex _lock;
119 #ifdef __APPLE__
120 static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
121 static bool _registeredForDyldUnloads;
122 #endif
123 static entry *_buffer;
124 static entry *_bufferUsed;
125 static entry *_bufferEnd;
126 static entry _initialBuffer[64];
127 };
128
129 template <typename A>
130 typename DwarfFDECache<A>::entry *
131 DwarfFDECache<A>::_buffer = _initialBuffer;
132
133 template <typename A>
134 typename DwarfFDECache<A>::entry *
135 DwarfFDECache<A>::_bufferUsed = _initialBuffer;
136
137 template <typename A>
138 typename DwarfFDECache<A>::entry *
139 DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
140
141 template <typename A>
142 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
143
144 template <typename A>
145 RWMutex DwarfFDECache<A>::_lock;
146
147 #ifdef __APPLE__
148 template <typename A>
149 bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
150 #endif
151
152 template <typename A>
findFDE(pint_t mh,pint_t pc)153 typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) {
154 pint_t result = 0;
155 _LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
156 for (entry *p = _buffer; p < _bufferUsed; ++p) {
157 if ((mh == p->mh) || (mh == kSearchAll)) {
158 if ((p->ip_start <= pc) && (pc < p->ip_end)) {
159 result = p->fde;
160 break;
161 }
162 }
163 }
164 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
165 return result;
166 }
167
168 template <typename A>
add(pint_t mh,pint_t ip_start,pint_t ip_end,pint_t fde)169 void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
170 pint_t fde) {
171 #if !defined(_LIBUNWIND_NO_HEAP)
172 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
173 if (_bufferUsed >= _bufferEnd) {
174 size_t oldSize = (size_t)(_bufferEnd - _buffer);
175 size_t newSize = oldSize * 4;
176 // Can't use operator new (we are below it).
177 entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
178 memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
179 if (_buffer != _initialBuffer)
180 free(_buffer);
181 _buffer = newBuffer;
182 _bufferUsed = &newBuffer[oldSize];
183 _bufferEnd = &newBuffer[newSize];
184 }
185 _bufferUsed->mh = mh;
186 _bufferUsed->ip_start = ip_start;
187 _bufferUsed->ip_end = ip_end;
188 _bufferUsed->fde = fde;
189 ++_bufferUsed;
190 #ifdef __APPLE__
191 if (!_registeredForDyldUnloads) {
192 _dyld_register_func_for_remove_image(&dyldUnloadHook);
193 _registeredForDyldUnloads = true;
194 }
195 #endif
196 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
197 #endif
198 }
199
200 template <typename A>
removeAllIn(pint_t mh)201 void DwarfFDECache<A>::removeAllIn(pint_t mh) {
202 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
203 entry *d = _buffer;
204 for (const entry *s = _buffer; s < _bufferUsed; ++s) {
205 if (s->mh != mh) {
206 if (d != s)
207 *d = *s;
208 ++d;
209 }
210 }
211 _bufferUsed = d;
212 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
213 }
214
215 #ifdef __APPLE__
216 template <typename A>
dyldUnloadHook(const struct mach_header * mh,intptr_t)217 void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
218 removeAllIn((pint_t) mh);
219 }
220 #endif
221
222 template <typename A>
iterateCacheEntries(void (* func)(unw_word_t ip_start,unw_word_t ip_end,unw_word_t fde,unw_word_t mh))223 void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
224 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
225 _LIBUNWIND_LOG_IF_FALSE(_lock.lock());
226 for (entry *p = _buffer; p < _bufferUsed; ++p) {
227 (*func)(p->ip_start, p->ip_end, p->fde, p->mh);
228 }
229 _LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
230 }
231 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
232
233
234 #define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field))
235
236 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
237 template <typename A> class UnwindSectionHeader {
238 public:
UnwindSectionHeader(A & addressSpace,typename A::pint_t addr)239 UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
240 : _addressSpace(addressSpace), _addr(addr) {}
241
version() const242 uint32_t version() const {
243 return _addressSpace.get32(_addr +
244 offsetof(unwind_info_section_header, version));
245 }
commonEncodingsArraySectionOffset() const246 uint32_t commonEncodingsArraySectionOffset() const {
247 return _addressSpace.get32(_addr +
248 offsetof(unwind_info_section_header,
249 commonEncodingsArraySectionOffset));
250 }
commonEncodingsArrayCount() const251 uint32_t commonEncodingsArrayCount() const {
252 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
253 commonEncodingsArrayCount));
254 }
personalityArraySectionOffset() const255 uint32_t personalityArraySectionOffset() const {
256 return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
257 personalityArraySectionOffset));
258 }
personalityArrayCount() const259 uint32_t personalityArrayCount() const {
260 return _addressSpace.get32(
261 _addr + offsetof(unwind_info_section_header, personalityArrayCount));
262 }
indexSectionOffset() const263 uint32_t indexSectionOffset() const {
264 return _addressSpace.get32(
265 _addr + offsetof(unwind_info_section_header, indexSectionOffset));
266 }
indexCount() const267 uint32_t indexCount() const {
268 return _addressSpace.get32(
269 _addr + offsetof(unwind_info_section_header, indexCount));
270 }
271
272 private:
273 A &_addressSpace;
274 typename A::pint_t _addr;
275 };
276
277 template <typename A> class UnwindSectionIndexArray {
278 public:
UnwindSectionIndexArray(A & addressSpace,typename A::pint_t addr)279 UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
280 : _addressSpace(addressSpace), _addr(addr) {}
281
functionOffset(uint32_t index) const282 uint32_t functionOffset(uint32_t index) const {
283 return _addressSpace.get32(
284 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
285 functionOffset));
286 }
secondLevelPagesSectionOffset(uint32_t index) const287 uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
288 return _addressSpace.get32(
289 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
290 secondLevelPagesSectionOffset));
291 }
lsdaIndexArraySectionOffset(uint32_t index) const292 uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
293 return _addressSpace.get32(
294 _addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
295 lsdaIndexArraySectionOffset));
296 }
297
298 private:
299 A &_addressSpace;
300 typename A::pint_t _addr;
301 };
302
303 template <typename A> class UnwindSectionRegularPageHeader {
304 public:
UnwindSectionRegularPageHeader(A & addressSpace,typename A::pint_t addr)305 UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
306 : _addressSpace(addressSpace), _addr(addr) {}
307
kind() const308 uint32_t kind() const {
309 return _addressSpace.get32(
310 _addr + offsetof(unwind_info_regular_second_level_page_header, kind));
311 }
entryPageOffset() const312 uint16_t entryPageOffset() const {
313 return _addressSpace.get16(
314 _addr + offsetof(unwind_info_regular_second_level_page_header,
315 entryPageOffset));
316 }
entryCount() const317 uint16_t entryCount() const {
318 return _addressSpace.get16(
319 _addr +
320 offsetof(unwind_info_regular_second_level_page_header, entryCount));
321 }
322
323 private:
324 A &_addressSpace;
325 typename A::pint_t _addr;
326 };
327
328 template <typename A> class UnwindSectionRegularArray {
329 public:
UnwindSectionRegularArray(A & addressSpace,typename A::pint_t addr)330 UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
331 : _addressSpace(addressSpace), _addr(addr) {}
332
functionOffset(uint32_t index) const333 uint32_t functionOffset(uint32_t index) const {
334 return _addressSpace.get32(
335 _addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
336 functionOffset));
337 }
encoding(uint32_t index) const338 uint32_t encoding(uint32_t index) const {
339 return _addressSpace.get32(
340 _addr +
341 arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
342 }
343
344 private:
345 A &_addressSpace;
346 typename A::pint_t _addr;
347 };
348
349 template <typename A> class UnwindSectionCompressedPageHeader {
350 public:
UnwindSectionCompressedPageHeader(A & addressSpace,typename A::pint_t addr)351 UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
352 : _addressSpace(addressSpace), _addr(addr) {}
353
kind() const354 uint32_t kind() const {
355 return _addressSpace.get32(
356 _addr +
357 offsetof(unwind_info_compressed_second_level_page_header, kind));
358 }
entryPageOffset() const359 uint16_t entryPageOffset() const {
360 return _addressSpace.get16(
361 _addr + offsetof(unwind_info_compressed_second_level_page_header,
362 entryPageOffset));
363 }
entryCount() const364 uint16_t entryCount() const {
365 return _addressSpace.get16(
366 _addr +
367 offsetof(unwind_info_compressed_second_level_page_header, entryCount));
368 }
encodingsPageOffset() const369 uint16_t encodingsPageOffset() const {
370 return _addressSpace.get16(
371 _addr + offsetof(unwind_info_compressed_second_level_page_header,
372 encodingsPageOffset));
373 }
encodingsCount() const374 uint16_t encodingsCount() const {
375 return _addressSpace.get16(
376 _addr + offsetof(unwind_info_compressed_second_level_page_header,
377 encodingsCount));
378 }
379
380 private:
381 A &_addressSpace;
382 typename A::pint_t _addr;
383 };
384
385 template <typename A> class UnwindSectionCompressedArray {
386 public:
UnwindSectionCompressedArray(A & addressSpace,typename A::pint_t addr)387 UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
388 : _addressSpace(addressSpace), _addr(addr) {}
389
functionOffset(uint32_t index) const390 uint32_t functionOffset(uint32_t index) const {
391 return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
392 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
393 }
encodingIndex(uint32_t index) const394 uint16_t encodingIndex(uint32_t index) const {
395 return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
396 _addressSpace.get32(_addr + index * sizeof(uint32_t)));
397 }
398
399 private:
400 A &_addressSpace;
401 typename A::pint_t _addr;
402 };
403
404 template <typename A> class UnwindSectionLsdaArray {
405 public:
UnwindSectionLsdaArray(A & addressSpace,typename A::pint_t addr)406 UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
407 : _addressSpace(addressSpace), _addr(addr) {}
408
functionOffset(uint32_t index) const409 uint32_t functionOffset(uint32_t index) const {
410 return _addressSpace.get32(
411 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
412 index, functionOffset));
413 }
lsdaOffset(uint32_t index) const414 uint32_t lsdaOffset(uint32_t index) const {
415 return _addressSpace.get32(
416 _addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
417 index, lsdaOffset));
418 }
419
420 private:
421 A &_addressSpace;
422 typename A::pint_t _addr;
423 };
424 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
425
426 class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
427 public:
428 // NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
429 // This avoids an unnecessary dependency to libc++abi.
operator delete(void *,size_t)430 void operator delete(void *, size_t) {}
431
~AbstractUnwindCursor()432 virtual ~AbstractUnwindCursor() {}
validReg(int)433 virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
getReg(int)434 virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
setReg(int,unw_word_t)435 virtual void setReg(int, unw_word_t) {
436 _LIBUNWIND_ABORT("setReg not implemented");
437 }
validFloatReg(int)438 virtual bool validFloatReg(int) {
439 _LIBUNWIND_ABORT("validFloatReg not implemented");
440 }
getFloatReg(int)441 virtual unw_fpreg_t getFloatReg(int) {
442 _LIBUNWIND_ABORT("getFloatReg not implemented");
443 }
setFloatReg(int,unw_fpreg_t)444 virtual void setFloatReg(int, unw_fpreg_t) {
445 _LIBUNWIND_ABORT("setFloatReg not implemented");
446 }
step(bool=false)447 virtual int step(bool = false) { _LIBUNWIND_ABORT("step not implemented"); }
getInfo(unw_proc_info_t *)448 virtual void getInfo(unw_proc_info_t *) {
449 _LIBUNWIND_ABORT("getInfo not implemented");
450 }
jumpto()451 virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
isSignalFrame()452 virtual bool isSignalFrame() {
453 _LIBUNWIND_ABORT("isSignalFrame not implemented");
454 }
getFunctionName(char *,size_t,unw_word_t *)455 virtual bool getFunctionName(char *, size_t, unw_word_t *) {
456 _LIBUNWIND_ABORT("getFunctionName not implemented");
457 }
setInfoBasedOnIPRegister(bool=false)458 virtual void setInfoBasedOnIPRegister(bool = false) {
459 _LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
460 }
getRegisterName(int)461 virtual const char *getRegisterName(int) {
462 _LIBUNWIND_ABORT("getRegisterName not implemented");
463 }
464 #ifdef __arm__
saveVFPAsX()465 virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
466 #endif
467
468 #ifdef _AIX
getDataRelBase()469 virtual uintptr_t getDataRelBase() {
470 _LIBUNWIND_ABORT("getDataRelBase not implemented");
471 }
472 #endif
473
474 #if defined(_LIBUNWIND_USE_CET)
get_registers()475 virtual void *get_registers() {
476 _LIBUNWIND_ABORT("get_registers not implemented");
477 }
478 #endif
479 };
480
481 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
482
483 /// \c UnwindCursor contains all state (including all register values) during
484 /// an unwind. This is normally stack-allocated inside a unw_cursor_t.
485 template <typename A, typename R>
486 class UnwindCursor : public AbstractUnwindCursor {
487 typedef typename A::pint_t pint_t;
488 public:
489 UnwindCursor(unw_context_t *context, A &as);
490 UnwindCursor(CONTEXT *context, A &as);
491 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()492 virtual ~UnwindCursor() {}
493 virtual bool validReg(int);
494 virtual unw_word_t getReg(int);
495 virtual void setReg(int, unw_word_t);
496 virtual bool validFloatReg(int);
497 virtual unw_fpreg_t getFloatReg(int);
498 virtual void setFloatReg(int, unw_fpreg_t);
499 virtual int step(bool = false);
500 virtual void getInfo(unw_proc_info_t *);
501 virtual void jumpto();
502 virtual bool isSignalFrame();
503 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
504 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
505 virtual const char *getRegisterName(int num);
506 #ifdef __arm__
507 virtual void saveVFPAsX();
508 #endif
509
getDispatcherContext()510 DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
setDispatcherContext(DISPATCHER_CONTEXT * disp)511 void setDispatcherContext(DISPATCHER_CONTEXT *disp) { _dispContext = *disp; }
512
513 // libunwind does not and should not depend on C++ library which means that we
514 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)515 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
516
517 private:
518
getLastPC() const519 pint_t getLastPC() const { return _dispContext.ControlPc; }
setLastPC(pint_t pc)520 void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)521 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
522 #ifdef __arm__
523 // Remove the thumb bit; FunctionEntry ranges don't include the thumb bit.
524 pc &= ~1U;
525 #endif
526 // If pc points exactly at the end of the range, we might resolve the
527 // next function instead. Decrement pc by 1 to fit inside the current
528 // function.
529 pc -= 1;
530 _dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
531 &_dispContext.ImageBase,
532 _dispContext.HistoryTable);
533 *base = _dispContext.ImageBase;
534 return _dispContext.FunctionEntry;
535 }
536 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()537 int stepWithSEHData() {
538 _dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
539 _dispContext.ImageBase,
540 _dispContext.ControlPc,
541 _dispContext.FunctionEntry,
542 _dispContext.ContextRecord,
543 &_dispContext.HandlerData,
544 &_dispContext.EstablisherFrame,
545 NULL);
546 // Update some fields of the unwind info now, since we have them.
547 _info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
548 if (_dispContext.LanguageHandler) {
549 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
550 } else
551 _info.handler = 0;
552 return UNW_STEP_SUCCESS;
553 }
554
555 A &_addressSpace;
556 unw_proc_info_t _info;
557 DISPATCHER_CONTEXT _dispContext;
558 CONTEXT _msContext;
559 UNWIND_HISTORY_TABLE _histTable;
560 bool _unwindInfoMissing;
561 };
562
563
564 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)565 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
566 : _addressSpace(as), _unwindInfoMissing(false) {
567 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
568 "UnwindCursor<> does not fit in unw_cursor_t");
569 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
570 "UnwindCursor<> requires more alignment than unw_cursor_t");
571 memset(&_info, 0, sizeof(_info));
572 memset(&_histTable, 0, sizeof(_histTable));
573 _dispContext.ContextRecord = &_msContext;
574 _dispContext.HistoryTable = &_histTable;
575 // Initialize MS context from ours.
576 R r(context);
577 _msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
578 #if defined(_LIBUNWIND_TARGET_X86_64)
579 _msContext.Rax = r.getRegister(UNW_X86_64_RAX);
580 _msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
581 _msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
582 _msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
583 _msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
584 _msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
585 _msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
586 _msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
587 _msContext.R8 = r.getRegister(UNW_X86_64_R8);
588 _msContext.R9 = r.getRegister(UNW_X86_64_R9);
589 _msContext.R10 = r.getRegister(UNW_X86_64_R10);
590 _msContext.R11 = r.getRegister(UNW_X86_64_R11);
591 _msContext.R12 = r.getRegister(UNW_X86_64_R12);
592 _msContext.R13 = r.getRegister(UNW_X86_64_R13);
593 _msContext.R14 = r.getRegister(UNW_X86_64_R14);
594 _msContext.R15 = r.getRegister(UNW_X86_64_R15);
595 _msContext.Rip = r.getRegister(UNW_REG_IP);
596 union {
597 v128 v;
598 M128A m;
599 } t;
600 t.v = r.getVectorRegister(UNW_X86_64_XMM0);
601 _msContext.Xmm0 = t.m;
602 t.v = r.getVectorRegister(UNW_X86_64_XMM1);
603 _msContext.Xmm1 = t.m;
604 t.v = r.getVectorRegister(UNW_X86_64_XMM2);
605 _msContext.Xmm2 = t.m;
606 t.v = r.getVectorRegister(UNW_X86_64_XMM3);
607 _msContext.Xmm3 = t.m;
608 t.v = r.getVectorRegister(UNW_X86_64_XMM4);
609 _msContext.Xmm4 = t.m;
610 t.v = r.getVectorRegister(UNW_X86_64_XMM5);
611 _msContext.Xmm5 = t.m;
612 t.v = r.getVectorRegister(UNW_X86_64_XMM6);
613 _msContext.Xmm6 = t.m;
614 t.v = r.getVectorRegister(UNW_X86_64_XMM7);
615 _msContext.Xmm7 = t.m;
616 t.v = r.getVectorRegister(UNW_X86_64_XMM8);
617 _msContext.Xmm8 = t.m;
618 t.v = r.getVectorRegister(UNW_X86_64_XMM9);
619 _msContext.Xmm9 = t.m;
620 t.v = r.getVectorRegister(UNW_X86_64_XMM10);
621 _msContext.Xmm10 = t.m;
622 t.v = r.getVectorRegister(UNW_X86_64_XMM11);
623 _msContext.Xmm11 = t.m;
624 t.v = r.getVectorRegister(UNW_X86_64_XMM12);
625 _msContext.Xmm12 = t.m;
626 t.v = r.getVectorRegister(UNW_X86_64_XMM13);
627 _msContext.Xmm13 = t.m;
628 t.v = r.getVectorRegister(UNW_X86_64_XMM14);
629 _msContext.Xmm14 = t.m;
630 t.v = r.getVectorRegister(UNW_X86_64_XMM15);
631 _msContext.Xmm15 = t.m;
632 #elif defined(_LIBUNWIND_TARGET_ARM)
633 _msContext.R0 = r.getRegister(UNW_ARM_R0);
634 _msContext.R1 = r.getRegister(UNW_ARM_R1);
635 _msContext.R2 = r.getRegister(UNW_ARM_R2);
636 _msContext.R3 = r.getRegister(UNW_ARM_R3);
637 _msContext.R4 = r.getRegister(UNW_ARM_R4);
638 _msContext.R5 = r.getRegister(UNW_ARM_R5);
639 _msContext.R6 = r.getRegister(UNW_ARM_R6);
640 _msContext.R7 = r.getRegister(UNW_ARM_R7);
641 _msContext.R8 = r.getRegister(UNW_ARM_R8);
642 _msContext.R9 = r.getRegister(UNW_ARM_R9);
643 _msContext.R10 = r.getRegister(UNW_ARM_R10);
644 _msContext.R11 = r.getRegister(UNW_ARM_R11);
645 _msContext.R12 = r.getRegister(UNW_ARM_R12);
646 _msContext.Sp = r.getRegister(UNW_ARM_SP);
647 _msContext.Lr = r.getRegister(UNW_ARM_LR);
648 _msContext.Pc = r.getRegister(UNW_ARM_IP);
649 for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
650 union {
651 uint64_t w;
652 double d;
653 } d;
654 d.d = r.getFloatRegister(i);
655 _msContext.D[i - UNW_ARM_D0] = d.w;
656 }
657 #elif defined(_LIBUNWIND_TARGET_AARCH64)
658 for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
659 _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
660 _msContext.Sp = r.getRegister(UNW_REG_SP);
661 _msContext.Pc = r.getRegister(UNW_REG_IP);
662 for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
663 _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
664 #endif
665 }
666
667 template <typename A, typename R>
UnwindCursor(CONTEXT * context,A & as)668 UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
669 : _addressSpace(as), _unwindInfoMissing(false) {
670 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
671 "UnwindCursor<> does not fit in unw_cursor_t");
672 memset(&_info, 0, sizeof(_info));
673 memset(&_histTable, 0, sizeof(_histTable));
674 _dispContext.ContextRecord = &_msContext;
675 _dispContext.HistoryTable = &_histTable;
676 _msContext = *context;
677 }
678
679
680 template <typename A, typename R>
validReg(int regNum)681 bool UnwindCursor<A, R>::validReg(int regNum) {
682 if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
683 #if defined(_LIBUNWIND_TARGET_X86_64)
684 if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_R15) return true;
685 #elif defined(_LIBUNWIND_TARGET_ARM)
686 if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
687 regNum == UNW_ARM_RA_AUTH_CODE)
688 return true;
689 #elif defined(_LIBUNWIND_TARGET_AARCH64)
690 if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
691 #endif
692 return false;
693 }
694
695 template <typename A, typename R>
getReg(int regNum)696 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
697 switch (regNum) {
698 #if defined(_LIBUNWIND_TARGET_X86_64)
699 case UNW_REG_IP: return _msContext.Rip;
700 case UNW_X86_64_RAX: return _msContext.Rax;
701 case UNW_X86_64_RDX: return _msContext.Rdx;
702 case UNW_X86_64_RCX: return _msContext.Rcx;
703 case UNW_X86_64_RBX: return _msContext.Rbx;
704 case UNW_REG_SP:
705 case UNW_X86_64_RSP: return _msContext.Rsp;
706 case UNW_X86_64_RBP: return _msContext.Rbp;
707 case UNW_X86_64_RSI: return _msContext.Rsi;
708 case UNW_X86_64_RDI: return _msContext.Rdi;
709 case UNW_X86_64_R8: return _msContext.R8;
710 case UNW_X86_64_R9: return _msContext.R9;
711 case UNW_X86_64_R10: return _msContext.R10;
712 case UNW_X86_64_R11: return _msContext.R11;
713 case UNW_X86_64_R12: return _msContext.R12;
714 case UNW_X86_64_R13: return _msContext.R13;
715 case UNW_X86_64_R14: return _msContext.R14;
716 case UNW_X86_64_R15: return _msContext.R15;
717 #elif defined(_LIBUNWIND_TARGET_ARM)
718 case UNW_ARM_R0: return _msContext.R0;
719 case UNW_ARM_R1: return _msContext.R1;
720 case UNW_ARM_R2: return _msContext.R2;
721 case UNW_ARM_R3: return _msContext.R3;
722 case UNW_ARM_R4: return _msContext.R4;
723 case UNW_ARM_R5: return _msContext.R5;
724 case UNW_ARM_R6: return _msContext.R6;
725 case UNW_ARM_R7: return _msContext.R7;
726 case UNW_ARM_R8: return _msContext.R8;
727 case UNW_ARM_R9: return _msContext.R9;
728 case UNW_ARM_R10: return _msContext.R10;
729 case UNW_ARM_R11: return _msContext.R11;
730 case UNW_ARM_R12: return _msContext.R12;
731 case UNW_REG_SP:
732 case UNW_ARM_SP: return _msContext.Sp;
733 case UNW_ARM_LR: return _msContext.Lr;
734 case UNW_REG_IP:
735 case UNW_ARM_IP: return _msContext.Pc;
736 #elif defined(_LIBUNWIND_TARGET_AARCH64)
737 case UNW_REG_SP: return _msContext.Sp;
738 case UNW_REG_IP: return _msContext.Pc;
739 default: return _msContext.X[regNum - UNW_AARCH64_X0];
740 #endif
741 }
742 _LIBUNWIND_ABORT("unsupported register");
743 }
744
745 template <typename A, typename R>
setReg(int regNum,unw_word_t value)746 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
747 switch (regNum) {
748 #if defined(_LIBUNWIND_TARGET_X86_64)
749 case UNW_REG_IP: _msContext.Rip = value; break;
750 case UNW_X86_64_RAX: _msContext.Rax = value; break;
751 case UNW_X86_64_RDX: _msContext.Rdx = value; break;
752 case UNW_X86_64_RCX: _msContext.Rcx = value; break;
753 case UNW_X86_64_RBX: _msContext.Rbx = value; break;
754 case UNW_REG_SP:
755 case UNW_X86_64_RSP: _msContext.Rsp = value; break;
756 case UNW_X86_64_RBP: _msContext.Rbp = value; break;
757 case UNW_X86_64_RSI: _msContext.Rsi = value; break;
758 case UNW_X86_64_RDI: _msContext.Rdi = value; break;
759 case UNW_X86_64_R8: _msContext.R8 = value; break;
760 case UNW_X86_64_R9: _msContext.R9 = value; break;
761 case UNW_X86_64_R10: _msContext.R10 = value; break;
762 case UNW_X86_64_R11: _msContext.R11 = value; break;
763 case UNW_X86_64_R12: _msContext.R12 = value; break;
764 case UNW_X86_64_R13: _msContext.R13 = value; break;
765 case UNW_X86_64_R14: _msContext.R14 = value; break;
766 case UNW_X86_64_R15: _msContext.R15 = value; break;
767 #elif defined(_LIBUNWIND_TARGET_ARM)
768 case UNW_ARM_R0: _msContext.R0 = value; break;
769 case UNW_ARM_R1: _msContext.R1 = value; break;
770 case UNW_ARM_R2: _msContext.R2 = value; break;
771 case UNW_ARM_R3: _msContext.R3 = value; break;
772 case UNW_ARM_R4: _msContext.R4 = value; break;
773 case UNW_ARM_R5: _msContext.R5 = value; break;
774 case UNW_ARM_R6: _msContext.R6 = value; break;
775 case UNW_ARM_R7: _msContext.R7 = value; break;
776 case UNW_ARM_R8: _msContext.R8 = value; break;
777 case UNW_ARM_R9: _msContext.R9 = value; break;
778 case UNW_ARM_R10: _msContext.R10 = value; break;
779 case UNW_ARM_R11: _msContext.R11 = value; break;
780 case UNW_ARM_R12: _msContext.R12 = value; break;
781 case UNW_REG_SP:
782 case UNW_ARM_SP: _msContext.Sp = value; break;
783 case UNW_ARM_LR: _msContext.Lr = value; break;
784 case UNW_REG_IP:
785 case UNW_ARM_IP: _msContext.Pc = value; break;
786 #elif defined(_LIBUNWIND_TARGET_AARCH64)
787 case UNW_REG_SP: _msContext.Sp = value; break;
788 case UNW_REG_IP: _msContext.Pc = value; break;
789 case UNW_AARCH64_X0:
790 case UNW_AARCH64_X1:
791 case UNW_AARCH64_X2:
792 case UNW_AARCH64_X3:
793 case UNW_AARCH64_X4:
794 case UNW_AARCH64_X5:
795 case UNW_AARCH64_X6:
796 case UNW_AARCH64_X7:
797 case UNW_AARCH64_X8:
798 case UNW_AARCH64_X9:
799 case UNW_AARCH64_X10:
800 case UNW_AARCH64_X11:
801 case UNW_AARCH64_X12:
802 case UNW_AARCH64_X13:
803 case UNW_AARCH64_X14:
804 case UNW_AARCH64_X15:
805 case UNW_AARCH64_X16:
806 case UNW_AARCH64_X17:
807 case UNW_AARCH64_X18:
808 case UNW_AARCH64_X19:
809 case UNW_AARCH64_X20:
810 case UNW_AARCH64_X21:
811 case UNW_AARCH64_X22:
812 case UNW_AARCH64_X23:
813 case UNW_AARCH64_X24:
814 case UNW_AARCH64_X25:
815 case UNW_AARCH64_X26:
816 case UNW_AARCH64_X27:
817 case UNW_AARCH64_X28:
818 case UNW_AARCH64_FP:
819 case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
820 #endif
821 default:
822 _LIBUNWIND_ABORT("unsupported register");
823 }
824 }
825
826 template <typename A, typename R>
validFloatReg(int regNum)827 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
828 #if defined(_LIBUNWIND_TARGET_ARM)
829 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
830 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
831 #elif defined(_LIBUNWIND_TARGET_AARCH64)
832 if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
833 #else
834 (void)regNum;
835 #endif
836 return false;
837 }
838
839 template <typename A, typename R>
getFloatReg(int regNum)840 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
841 #if defined(_LIBUNWIND_TARGET_ARM)
842 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
843 union {
844 uint32_t w;
845 float f;
846 } d;
847 d.w = _msContext.S[regNum - UNW_ARM_S0];
848 return d.f;
849 }
850 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
851 union {
852 uint64_t w;
853 double d;
854 } d;
855 d.w = _msContext.D[regNum - UNW_ARM_D0];
856 return d.d;
857 }
858 _LIBUNWIND_ABORT("unsupported float register");
859 #elif defined(_LIBUNWIND_TARGET_AARCH64)
860 return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
861 #else
862 (void)regNum;
863 _LIBUNWIND_ABORT("float registers unimplemented");
864 #endif
865 }
866
867 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)868 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
869 #if defined(_LIBUNWIND_TARGET_ARM)
870 if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
871 union {
872 uint32_t w;
873 float f;
874 } d;
875 d.f = (float)value;
876 _msContext.S[regNum - UNW_ARM_S0] = d.w;
877 }
878 if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
879 union {
880 uint64_t w;
881 double d;
882 } d;
883 d.d = value;
884 _msContext.D[regNum - UNW_ARM_D0] = d.w;
885 }
886 _LIBUNWIND_ABORT("unsupported float register");
887 #elif defined(_LIBUNWIND_TARGET_AARCH64)
888 _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
889 #else
890 (void)regNum;
891 (void)value;
892 _LIBUNWIND_ABORT("float registers unimplemented");
893 #endif
894 }
895
jumpto()896 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
897 RtlRestoreContext(&_msContext, nullptr);
898 }
899
900 #ifdef __arm__
saveVFPAsX()901 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
902 #endif
903
904 template <typename A, typename R>
getRegisterName(int regNum)905 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
906 return R::getRegisterName(regNum);
907 }
908
isSignalFrame()909 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
910 return false;
911 }
912
913 #else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
914
915 /// UnwindCursor contains all state (including all register values) during
916 /// an unwind. This is normally stack allocated inside a unw_cursor_t.
917 template <typename A, typename R>
918 class UnwindCursor : public AbstractUnwindCursor{
919 typedef typename A::pint_t pint_t;
920 public:
921 UnwindCursor(unw_context_t *context, A &as);
922 UnwindCursor(A &as, void *threadArg);
~UnwindCursor()923 virtual ~UnwindCursor() {}
924 virtual bool validReg(int);
925 virtual unw_word_t getReg(int);
926 virtual void setReg(int, unw_word_t);
927 virtual bool validFloatReg(int);
928 virtual unw_fpreg_t getFloatReg(int);
929 virtual void setFloatReg(int, unw_fpreg_t);
930 virtual int step(bool stage2 = false);
931 virtual void getInfo(unw_proc_info_t *);
932 virtual void jumpto();
933 virtual bool isSignalFrame();
934 virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
935 virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
936 virtual const char *getRegisterName(int num);
937 #ifdef __arm__
938 virtual void saveVFPAsX();
939 #endif
940
941 #ifdef _AIX
942 virtual uintptr_t getDataRelBase();
943 #endif
944
945 #if defined(_LIBUNWIND_USE_CET)
get_registers()946 virtual void *get_registers() { return &_registers; }
947 #endif
948
949 // libunwind does not and should not depend on C++ library which means that we
950 // need our own definition of inline placement new.
operator new(size_t,UnwindCursor<A,R> * p)951 static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
952
953 private:
954
955 #if defined(_LIBUNWIND_ARM_EHABI)
956 bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections §s);
957
stepWithEHABI()958 int stepWithEHABI() {
959 size_t len = 0;
960 size_t off = 0;
961 // FIXME: Calling decode_eht_entry() here is violating the libunwind
962 // abstraction layer.
963 const uint32_t *ehtp =
964 decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
965 &off, &len);
966 if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
967 _URC_CONTINUE_UNWIND)
968 return UNW_STEP_END;
969 return UNW_STEP_SUCCESS;
970 }
971 #endif
972
973 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
setInfoForSigReturn()974 bool setInfoForSigReturn() {
975 R dummy;
976 return setInfoForSigReturn(dummy);
977 }
stepThroughSigReturn()978 int stepThroughSigReturn() {
979 R dummy;
980 return stepThroughSigReturn(dummy);
981 }
982 #if defined(_LIBUNWIND_TARGET_AARCH64)
983 bool setInfoForSigReturn(Registers_arm64 &);
984 int stepThroughSigReturn(Registers_arm64 &);
985 #endif
986 #if defined(_LIBUNWIND_TARGET_S390X)
987 bool setInfoForSigReturn(Registers_s390x &);
988 int stepThroughSigReturn(Registers_s390x &);
989 #endif
setInfoForSigReturn(Registers &)990 template <typename Registers> bool setInfoForSigReturn(Registers &) {
991 return false;
992 }
stepThroughSigReturn(Registers &)993 template <typename Registers> int stepThroughSigReturn(Registers &) {
994 return UNW_STEP_END;
995 }
996 #endif
997
998 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
999 bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1000 const typename CFI_Parser<A>::CIE_Info &cieInfo,
1001 pint_t pc, uintptr_t dso_base);
1002 bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections §s,
1003 uint32_t fdeSectionOffsetHint=0);
stepWithDwarfFDE(bool stage2)1004 int stepWithDwarfFDE(bool stage2) {
1005 return DwarfInstructions<A, R>::stepWithDwarf(
1006 _addressSpace, (pint_t)this->getReg(UNW_REG_IP),
1007 (pint_t)_info.unwind_info, _registers, _isSignalFrame, stage2);
1008 }
1009 #endif
1010
1011 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1012 bool getInfoFromCompactEncodingSection(pint_t pc,
1013 const UnwindInfoSections §s);
stepWithCompactEncoding(bool stage2=false)1014 int stepWithCompactEncoding(bool stage2 = false) {
1015 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1016 if ( compactSaysUseDwarf() )
1017 return stepWithDwarfFDE(stage2);
1018 #endif
1019 R dummy;
1020 return stepWithCompactEncoding(dummy);
1021 }
1022
1023 #if defined(_LIBUNWIND_TARGET_X86_64)
stepWithCompactEncoding(Registers_x86_64 &)1024 int stepWithCompactEncoding(Registers_x86_64 &) {
1025 return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
1026 _info.format, _info.start_ip, _addressSpace, _registers);
1027 }
1028 #endif
1029
1030 #if defined(_LIBUNWIND_TARGET_I386)
stepWithCompactEncoding(Registers_x86 &)1031 int stepWithCompactEncoding(Registers_x86 &) {
1032 return CompactUnwinder_x86<A>::stepWithCompactEncoding(
1033 _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
1034 }
1035 #endif
1036
1037 #if defined(_LIBUNWIND_TARGET_PPC)
stepWithCompactEncoding(Registers_ppc &)1038 int stepWithCompactEncoding(Registers_ppc &) {
1039 return UNW_EINVAL;
1040 }
1041 #endif
1042
1043 #if defined(_LIBUNWIND_TARGET_PPC64)
stepWithCompactEncoding(Registers_ppc64 &)1044 int stepWithCompactEncoding(Registers_ppc64 &) {
1045 return UNW_EINVAL;
1046 }
1047 #endif
1048
1049
1050 #if defined(_LIBUNWIND_TARGET_AARCH64)
stepWithCompactEncoding(Registers_arm64 &)1051 int stepWithCompactEncoding(Registers_arm64 &) {
1052 return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
1053 _info.format, _info.start_ip, _addressSpace, _registers);
1054 }
1055 #endif
1056
1057 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
stepWithCompactEncoding(Registers_mips_o32 &)1058 int stepWithCompactEncoding(Registers_mips_o32 &) {
1059 return UNW_EINVAL;
1060 }
1061 #endif
1062
1063 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
stepWithCompactEncoding(Registers_mips_newabi &)1064 int stepWithCompactEncoding(Registers_mips_newabi &) {
1065 return UNW_EINVAL;
1066 }
1067 #endif
1068
1069 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
stepWithCompactEncoding(Registers_loongarch &)1070 int stepWithCompactEncoding(Registers_loongarch &) { return UNW_EINVAL; }
1071 #endif
1072
1073 #if defined(_LIBUNWIND_TARGET_SPARC)
stepWithCompactEncoding(Registers_sparc &)1074 int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
1075 #endif
1076
1077 #if defined(_LIBUNWIND_TARGET_SPARC64)
stepWithCompactEncoding(Registers_sparc64 &)1078 int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
1079 #endif
1080
1081 #if defined (_LIBUNWIND_TARGET_RISCV)
stepWithCompactEncoding(Registers_riscv &)1082 int stepWithCompactEncoding(Registers_riscv &) {
1083 return UNW_EINVAL;
1084 }
1085 #endif
1086
compactSaysUseDwarf(uint32_t * offset=NULL) const1087 bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
1088 R dummy;
1089 return compactSaysUseDwarf(dummy, offset);
1090 }
1091
1092 #if defined(_LIBUNWIND_TARGET_X86_64)
compactSaysUseDwarf(Registers_x86_64 &,uint32_t * offset) const1093 bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
1094 if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
1095 if (offset)
1096 *offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
1097 return true;
1098 }
1099 return false;
1100 }
1101 #endif
1102
1103 #if defined(_LIBUNWIND_TARGET_I386)
compactSaysUseDwarf(Registers_x86 &,uint32_t * offset) const1104 bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
1105 if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
1106 if (offset)
1107 *offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
1108 return true;
1109 }
1110 return false;
1111 }
1112 #endif
1113
1114 #if defined(_LIBUNWIND_TARGET_PPC)
compactSaysUseDwarf(Registers_ppc &,uint32_t *) const1115 bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
1116 return true;
1117 }
1118 #endif
1119
1120 #if defined(_LIBUNWIND_TARGET_PPC64)
compactSaysUseDwarf(Registers_ppc64 &,uint32_t *) const1121 bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
1122 return true;
1123 }
1124 #endif
1125
1126 #if defined(_LIBUNWIND_TARGET_AARCH64)
compactSaysUseDwarf(Registers_arm64 &,uint32_t * offset) const1127 bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
1128 if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
1129 if (offset)
1130 *offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
1131 return true;
1132 }
1133 return false;
1134 }
1135 #endif
1136
1137 #if defined(_LIBUNWIND_TARGET_MIPS_O32)
compactSaysUseDwarf(Registers_mips_o32 &,uint32_t *) const1138 bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
1139 return true;
1140 }
1141 #endif
1142
1143 #if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
compactSaysUseDwarf(Registers_mips_newabi &,uint32_t *) const1144 bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
1145 return true;
1146 }
1147 #endif
1148
1149 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
compactSaysUseDwarf(Registers_loongarch &,uint32_t *) const1150 bool compactSaysUseDwarf(Registers_loongarch &, uint32_t *) const {
1151 return true;
1152 }
1153 #endif
1154
1155 #if defined(_LIBUNWIND_TARGET_SPARC)
compactSaysUseDwarf(Registers_sparc &,uint32_t *) const1156 bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
1157 #endif
1158
1159 #if defined(_LIBUNWIND_TARGET_SPARC64)
compactSaysUseDwarf(Registers_sparc64 &,uint32_t *) const1160 bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
1161 return true;
1162 }
1163 #endif
1164
1165 #if defined (_LIBUNWIND_TARGET_RISCV)
compactSaysUseDwarf(Registers_riscv &,uint32_t *) const1166 bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
1167 return true;
1168 }
1169 #endif
1170
1171 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1172
1173 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
dwarfEncoding() const1174 compact_unwind_encoding_t dwarfEncoding() const {
1175 R dummy;
1176 return dwarfEncoding(dummy);
1177 }
1178
1179 #if defined(_LIBUNWIND_TARGET_X86_64)
dwarfEncoding(Registers_x86_64 &) const1180 compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
1181 return UNWIND_X86_64_MODE_DWARF;
1182 }
1183 #endif
1184
1185 #if defined(_LIBUNWIND_TARGET_I386)
dwarfEncoding(Registers_x86 &) const1186 compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
1187 return UNWIND_X86_MODE_DWARF;
1188 }
1189 #endif
1190
1191 #if defined(_LIBUNWIND_TARGET_PPC)
dwarfEncoding(Registers_ppc &) const1192 compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
1193 return 0;
1194 }
1195 #endif
1196
1197 #if defined(_LIBUNWIND_TARGET_PPC64)
dwarfEncoding(Registers_ppc64 &) const1198 compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
1199 return 0;
1200 }
1201 #endif
1202
1203 #if defined(_LIBUNWIND_TARGET_AARCH64)
dwarfEncoding(Registers_arm64 &) const1204 compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
1205 return UNWIND_ARM64_MODE_DWARF;
1206 }
1207 #endif
1208
1209 #if defined(_LIBUNWIND_TARGET_ARM)
dwarfEncoding(Registers_arm &) const1210 compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
1211 return 0;
1212 }
1213 #endif
1214
1215 #if defined (_LIBUNWIND_TARGET_OR1K)
dwarfEncoding(Registers_or1k &) const1216 compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
1217 return 0;
1218 }
1219 #endif
1220
1221 #if defined (_LIBUNWIND_TARGET_HEXAGON)
dwarfEncoding(Registers_hexagon &) const1222 compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
1223 return 0;
1224 }
1225 #endif
1226
1227 #if defined (_LIBUNWIND_TARGET_MIPS_O32)
dwarfEncoding(Registers_mips_o32 &) const1228 compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
1229 return 0;
1230 }
1231 #endif
1232
1233 #if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
dwarfEncoding(Registers_mips_newabi &) const1234 compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
1235 return 0;
1236 }
1237 #endif
1238
1239 #if defined(_LIBUNWIND_TARGET_LOONGARCH)
dwarfEncoding(Registers_loongarch &) const1240 compact_unwind_encoding_t dwarfEncoding(Registers_loongarch &) const {
1241 return 0;
1242 }
1243 #endif
1244
1245 #if defined(_LIBUNWIND_TARGET_SPARC)
dwarfEncoding(Registers_sparc &) const1246 compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
1247 #endif
1248
1249 #if defined(_LIBUNWIND_TARGET_SPARC64)
dwarfEncoding(Registers_sparc64 &) const1250 compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
1251 return 0;
1252 }
1253 #endif
1254
1255 #if defined (_LIBUNWIND_TARGET_RISCV)
dwarfEncoding(Registers_riscv &) const1256 compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
1257 return 0;
1258 }
1259 #endif
1260
1261 #if defined (_LIBUNWIND_TARGET_S390X)
dwarfEncoding(Registers_s390x &) const1262 compact_unwind_encoding_t dwarfEncoding(Registers_s390x &) const {
1263 return 0;
1264 }
1265 #endif
1266
1267 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1268
1269 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1270 // For runtime environments using SEH unwind data without Windows runtime
1271 // support.
getLastPC() const1272 pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
setLastPC(pint_t pc)1273 void setLastPC(pint_t pc) { /* FIXME: Implement */ }
lookUpSEHUnwindInfo(pint_t pc,pint_t * base)1274 RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
1275 /* FIXME: Implement */
1276 *base = 0;
1277 return nullptr;
1278 }
1279 bool getInfoFromSEH(pint_t pc);
stepWithSEHData()1280 int stepWithSEHData() { /* FIXME: Implement */ return 0; }
1281 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1282
1283 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1284 bool getInfoFromTBTable(pint_t pc, R ®isters);
1285 int stepWithTBTable(pint_t pc, tbtable *TBTable, R ®isters,
1286 bool &isSignalFrame);
stepWithTBTableData()1287 int stepWithTBTableData() {
1288 return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
1289 reinterpret_cast<tbtable *>(_info.unwind_info),
1290 _registers, _isSignalFrame);
1291 }
1292 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1293
1294 A &_addressSpace;
1295 R _registers;
1296 unw_proc_info_t _info;
1297 bool _unwindInfoMissing;
1298 bool _isSignalFrame;
1299 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
1300 bool _isSigReturn = false;
1301 #endif
1302 };
1303
1304
1305 template <typename A, typename R>
UnwindCursor(unw_context_t * context,A & as)1306 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
1307 : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
1308 _isSignalFrame(false) {
1309 static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
1310 "UnwindCursor<> does not fit in unw_cursor_t");
1311 static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
1312 "UnwindCursor<> requires more alignment than unw_cursor_t");
1313 memset(&_info, 0, sizeof(_info));
1314 }
1315
1316 template <typename A, typename R>
UnwindCursor(A & as,void *)1317 UnwindCursor<A, R>::UnwindCursor(A &as, void *)
1318 : _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
1319 memset(&_info, 0, sizeof(_info));
1320 // FIXME
1321 // fill in _registers from thread arg
1322 }
1323
1324
1325 template <typename A, typename R>
validReg(int regNum)1326 bool UnwindCursor<A, R>::validReg(int regNum) {
1327 return _registers.validRegister(regNum);
1328 }
1329
1330 template <typename A, typename R>
getReg(int regNum)1331 unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
1332 return _registers.getRegister(regNum);
1333 }
1334
1335 template <typename A, typename R>
setReg(int regNum,unw_word_t value)1336 void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
1337 _registers.setRegister(regNum, (typename A::pint_t)value);
1338 }
1339
1340 template <typename A, typename R>
validFloatReg(int regNum)1341 bool UnwindCursor<A, R>::validFloatReg(int regNum) {
1342 return _registers.validFloatRegister(regNum);
1343 }
1344
1345 template <typename A, typename R>
getFloatReg(int regNum)1346 unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
1347 return _registers.getFloatRegister(regNum);
1348 }
1349
1350 template <typename A, typename R>
setFloatReg(int regNum,unw_fpreg_t value)1351 void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
1352 _registers.setFloatRegister(regNum, value);
1353 }
1354
jumpto()1355 template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
1356 _registers.jumpto();
1357 }
1358
1359 #ifdef __arm__
saveVFPAsX()1360 template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
1361 _registers.saveVFPAsX();
1362 }
1363 #endif
1364
1365 #ifdef _AIX
1366 template <typename A, typename R>
getDataRelBase()1367 uintptr_t UnwindCursor<A, R>::getDataRelBase() {
1368 return reinterpret_cast<uintptr_t>(_info.extra);
1369 }
1370 #endif
1371
1372 template <typename A, typename R>
getRegisterName(int regNum)1373 const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
1374 return _registers.getRegisterName(regNum);
1375 }
1376
isSignalFrame()1377 template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
1378 return _isSignalFrame;
1379 }
1380
1381 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1382
1383 #if defined(_LIBUNWIND_ARM_EHABI)
1384 template<typename A>
1385 struct EHABISectionIterator {
1386 typedef EHABISectionIterator _Self;
1387
1388 typedef typename A::pint_t value_type;
1389 typedef typename A::pint_t* pointer;
1390 typedef typename A::pint_t& reference;
1391 typedef size_t size_type;
1392 typedef size_t difference_type;
1393
beginlibunwind::EHABISectionIterator1394 static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
1395 return _Self(addressSpace, sects, 0);
1396 }
endlibunwind::EHABISectionIterator1397 static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
1398 return _Self(addressSpace, sects,
1399 sects.arm_section_length / sizeof(EHABIIndexEntry));
1400 }
1401
EHABISectionIteratorlibunwind::EHABISectionIterator1402 EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
1403 : _i(i), _addressSpace(&addressSpace), _sects(§s) {}
1404
operator ++libunwind::EHABISectionIterator1405 _Self& operator++() { ++_i; return *this; }
operator +=libunwind::EHABISectionIterator1406 _Self& operator+=(size_t a) { _i += a; return *this; }
operator --libunwind::EHABISectionIterator1407 _Self& operator--() { assert(_i > 0); --_i; return *this; }
operator -=libunwind::EHABISectionIterator1408 _Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
1409
operator +libunwind::EHABISectionIterator1410 _Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
operator -libunwind::EHABISectionIterator1411 _Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
1412
operator -libunwind::EHABISectionIterator1413 size_t operator-(const _Self& other) const { return _i - other._i; }
1414
operator ==libunwind::EHABISectionIterator1415 bool operator==(const _Self& other) const {
1416 assert(_addressSpace == other._addressSpace);
1417 assert(_sects == other._sects);
1418 return _i == other._i;
1419 }
1420
operator !=libunwind::EHABISectionIterator1421 bool operator!=(const _Self& other) const {
1422 assert(_addressSpace == other._addressSpace);
1423 assert(_sects == other._sects);
1424 return _i != other._i;
1425 }
1426
operator *libunwind::EHABISectionIterator1427 typename A::pint_t operator*() const { return functionAddress(); }
1428
functionAddresslibunwind::EHABISectionIterator1429 typename A::pint_t functionAddress() const {
1430 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1431 EHABIIndexEntry, _i, functionOffset);
1432 return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
1433 }
1434
dataAddresslibunwind::EHABISectionIterator1435 typename A::pint_t dataAddress() {
1436 typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
1437 EHABIIndexEntry, _i, data);
1438 return indexAddr;
1439 }
1440
1441 private:
1442 size_t _i;
1443 A* _addressSpace;
1444 const UnwindInfoSections* _sects;
1445 };
1446
1447 namespace {
1448
1449 template <typename A>
EHABISectionUpperBound(EHABISectionIterator<A> first,EHABISectionIterator<A> last,typename A::pint_t value)1450 EHABISectionIterator<A> EHABISectionUpperBound(
1451 EHABISectionIterator<A> first,
1452 EHABISectionIterator<A> last,
1453 typename A::pint_t value) {
1454 size_t len = last - first;
1455 while (len > 0) {
1456 size_t l2 = len / 2;
1457 EHABISectionIterator<A> m = first + l2;
1458 if (value < *m) {
1459 len = l2;
1460 } else {
1461 first = ++m;
1462 len -= l2 + 1;
1463 }
1464 }
1465 return first;
1466 }
1467
1468 }
1469
1470 template <typename A, typename R>
getInfoFromEHABISection(pint_t pc,const UnwindInfoSections & sects)1471 bool UnwindCursor<A, R>::getInfoFromEHABISection(
1472 pint_t pc,
1473 const UnwindInfoSections §s) {
1474 EHABISectionIterator<A> begin =
1475 EHABISectionIterator<A>::begin(_addressSpace, sects);
1476 EHABISectionIterator<A> end =
1477 EHABISectionIterator<A>::end(_addressSpace, sects);
1478 if (begin == end)
1479 return false;
1480
1481 EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
1482 if (itNextPC == begin)
1483 return false;
1484 EHABISectionIterator<A> itThisPC = itNextPC - 1;
1485
1486 pint_t thisPC = itThisPC.functionAddress();
1487 // If an exception is thrown from a function, corresponding to the last entry
1488 // in the table, we don't really know the function extent and have to choose a
1489 // value for nextPC. Choosing max() will allow the range check during trace to
1490 // succeed.
1491 pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
1492 pint_t indexDataAddr = itThisPC.dataAddress();
1493
1494 if (indexDataAddr == 0)
1495 return false;
1496
1497 uint32_t indexData = _addressSpace.get32(indexDataAddr);
1498 if (indexData == UNW_EXIDX_CANTUNWIND)
1499 return false;
1500
1501 // If the high bit is set, the exception handling table entry is inline inside
1502 // the index table entry on the second word (aka |indexDataAddr|). Otherwise,
1503 // the table points at an offset in the exception handling table (section 5
1504 // EHABI).
1505 pint_t exceptionTableAddr;
1506 uint32_t exceptionTableData;
1507 bool isSingleWordEHT;
1508 if (indexData & 0x80000000) {
1509 exceptionTableAddr = indexDataAddr;
1510 // TODO(ajwong): Should this data be 0?
1511 exceptionTableData = indexData;
1512 isSingleWordEHT = true;
1513 } else {
1514 exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
1515 exceptionTableData = _addressSpace.get32(exceptionTableAddr);
1516 isSingleWordEHT = false;
1517 }
1518
1519 // Now we know the 3 things:
1520 // exceptionTableAddr -- exception handler table entry.
1521 // exceptionTableData -- the data inside the first word of the eht entry.
1522 // isSingleWordEHT -- whether the entry is in the index.
1523 unw_word_t personalityRoutine = 0xbadf00d;
1524 bool scope32 = false;
1525 uintptr_t lsda;
1526
1527 // If the high bit in the exception handling table entry is set, the entry is
1528 // in compact form (section 6.3 EHABI).
1529 if (exceptionTableData & 0x80000000) {
1530 // Grab the index of the personality routine from the compact form.
1531 uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
1532 uint32_t extraWords = 0;
1533 switch (choice) {
1534 case 0:
1535 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
1536 extraWords = 0;
1537 scope32 = false;
1538 lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
1539 break;
1540 case 1:
1541 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
1542 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1543 scope32 = false;
1544 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1545 break;
1546 case 2:
1547 personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
1548 extraWords = (exceptionTableData & 0x00ff0000) >> 16;
1549 scope32 = true;
1550 lsda = exceptionTableAddr + (extraWords + 1) * 4;
1551 break;
1552 default:
1553 _LIBUNWIND_ABORT("unknown personality routine");
1554 return false;
1555 }
1556
1557 if (isSingleWordEHT) {
1558 if (extraWords != 0) {
1559 _LIBUNWIND_ABORT("index inlined table detected but pr function "
1560 "requires extra words");
1561 return false;
1562 }
1563 }
1564 } else {
1565 pint_t personalityAddr =
1566 exceptionTableAddr + signExtendPrel31(exceptionTableData);
1567 personalityRoutine = personalityAddr;
1568
1569 // ARM EHABI # 6.2, # 9.2
1570 //
1571 // +---- ehtp
1572 // v
1573 // +--------------------------------------+
1574 // | +--------+--------+--------+-------+ |
1575 // | |0| prel31 to personalityRoutine | |
1576 // | +--------+--------+--------+-------+ |
1577 // | | N | unwind opcodes | | <-- UnwindData
1578 // | +--------+--------+--------+-------+ |
1579 // | | Word 2 unwind opcodes | |
1580 // | +--------+--------+--------+-------+ |
1581 // | ... |
1582 // | +--------+--------+--------+-------+ |
1583 // | | Word N unwind opcodes | |
1584 // | +--------+--------+--------+-------+ |
1585 // | | LSDA | | <-- lsda
1586 // | | ... | |
1587 // | +--------+--------+--------+-------+ |
1588 // +--------------------------------------+
1589
1590 uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
1591 uint32_t FirstDataWord = *UnwindData;
1592 size_t N = ((FirstDataWord >> 24) & 0xff);
1593 size_t NDataWords = N + 1;
1594 lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
1595 }
1596
1597 _info.start_ip = thisPC;
1598 _info.end_ip = nextPC;
1599 _info.handler = personalityRoutine;
1600 _info.unwind_info = exceptionTableAddr;
1601 _info.lsda = lsda;
1602 // flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
1603 _info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum?
1604
1605 return true;
1606 }
1607 #endif
1608
1609 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1610 template <typename A, typename R>
getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info & fdeInfo,const typename CFI_Parser<A>::CIE_Info & cieInfo,pint_t pc,uintptr_t dso_base)1611 bool UnwindCursor<A, R>::getInfoFromFdeCie(
1612 const typename CFI_Parser<A>::FDE_Info &fdeInfo,
1613 const typename CFI_Parser<A>::CIE_Info &cieInfo, pint_t pc,
1614 uintptr_t dso_base) {
1615 typename CFI_Parser<A>::PrologInfo prolog;
1616 if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
1617 R::getArch(), &prolog)) {
1618 // Save off parsed FDE info
1619 _info.start_ip = fdeInfo.pcStart;
1620 _info.end_ip = fdeInfo.pcEnd;
1621 _info.lsda = fdeInfo.lsda;
1622 _info.handler = cieInfo.personality;
1623 // Some frameless functions need SP altered when resuming in function, so
1624 // propagate spExtraArgSize.
1625 _info.gp = prolog.spExtraArgSize;
1626 _info.flags = 0;
1627 _info.format = dwarfEncoding();
1628 _info.unwind_info = fdeInfo.fdeStart;
1629 _info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength);
1630 _info.extra = static_cast<unw_word_t>(dso_base);
1631 return true;
1632 }
1633 return false;
1634 }
1635
1636 template <typename A, typename R>
getInfoFromDwarfSection(pint_t pc,const UnwindInfoSections & sects,uint32_t fdeSectionOffsetHint)1637 bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
1638 const UnwindInfoSections §s,
1639 uint32_t fdeSectionOffsetHint) {
1640 typename CFI_Parser<A>::FDE_Info fdeInfo;
1641 typename CFI_Parser<A>::CIE_Info cieInfo;
1642 bool foundFDE = false;
1643 bool foundInCache = false;
1644 // If compact encoding table gave offset into dwarf section, go directly there
1645 if (fdeSectionOffsetHint != 0) {
1646 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1647 sects.dwarf_section_length,
1648 sects.dwarf_section + fdeSectionOffsetHint,
1649 &fdeInfo, &cieInfo);
1650 }
1651 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1652 if (!foundFDE && (sects.dwarf_index_section != 0)) {
1653 foundFDE = EHHeaderParser<A>::findFDE(
1654 _addressSpace, pc, sects.dwarf_index_section,
1655 (uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
1656 }
1657 #endif
1658 if (!foundFDE) {
1659 // otherwise, search cache of previously found FDEs.
1660 pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
1661 if (cachedFDE != 0) {
1662 foundFDE =
1663 CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1664 sects.dwarf_section_length,
1665 cachedFDE, &fdeInfo, &cieInfo);
1666 foundInCache = foundFDE;
1667 }
1668 }
1669 if (!foundFDE) {
1670 // Still not found, do full scan of __eh_frame section.
1671 foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
1672 sects.dwarf_section_length, 0,
1673 &fdeInfo, &cieInfo);
1674 }
1675 if (foundFDE) {
1676 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) {
1677 // Add to cache (to make next lookup faster) if we had no hint
1678 // and there was no index.
1679 if (!foundInCache && (fdeSectionOffsetHint == 0)) {
1680 #if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
1681 if (sects.dwarf_index_section == 0)
1682 #endif
1683 DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
1684 fdeInfo.fdeStart);
1685 }
1686 return true;
1687 }
1688 }
1689 //_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
1690 return false;
1691 }
1692 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
1693
1694
1695 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1696 template <typename A, typename R>
getInfoFromCompactEncodingSection(pint_t pc,const UnwindInfoSections & sects)1697 bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
1698 const UnwindInfoSections §s) {
1699 const bool log = false;
1700 if (log)
1701 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
1702 (uint64_t)pc, (uint64_t)sects.dso_base);
1703
1704 const UnwindSectionHeader<A> sectionHeader(_addressSpace,
1705 sects.compact_unwind_section);
1706 if (sectionHeader.version() != UNWIND_SECTION_VERSION)
1707 return false;
1708
1709 // do a binary search of top level index to find page with unwind info
1710 pint_t targetFunctionOffset = pc - sects.dso_base;
1711 const UnwindSectionIndexArray<A> topIndex(_addressSpace,
1712 sects.compact_unwind_section
1713 + sectionHeader.indexSectionOffset());
1714 uint32_t low = 0;
1715 uint32_t high = sectionHeader.indexCount();
1716 uint32_t last = high - 1;
1717 while (low < high) {
1718 uint32_t mid = (low + high) / 2;
1719 //if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
1720 //mid, low, high, topIndex.functionOffset(mid));
1721 if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
1722 if ((mid == last) ||
1723 (topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
1724 low = mid;
1725 break;
1726 } else {
1727 low = mid + 1;
1728 }
1729 } else {
1730 high = mid;
1731 }
1732 }
1733 const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
1734 const uint32_t firstLevelNextPageFunctionOffset =
1735 topIndex.functionOffset(low + 1);
1736 const pint_t secondLevelAddr =
1737 sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
1738 const pint_t lsdaArrayStartAddr =
1739 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
1740 const pint_t lsdaArrayEndAddr =
1741 sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
1742 if (log)
1743 fprintf(stderr, "\tfirst level search for result index=%d "
1744 "to secondLevelAddr=0x%llX\n",
1745 low, (uint64_t) secondLevelAddr);
1746 // do a binary search of second level page index
1747 uint32_t encoding = 0;
1748 pint_t funcStart = 0;
1749 pint_t funcEnd = 0;
1750 pint_t lsda = 0;
1751 pint_t personality = 0;
1752 uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
1753 if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
1754 // regular page
1755 UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
1756 secondLevelAddr);
1757 UnwindSectionRegularArray<A> pageIndex(
1758 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1759 // binary search looks for entry with e where index[e].offset <= pc <
1760 // index[e+1].offset
1761 if (log)
1762 fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
1763 "regular page starting at secondLevelAddr=0x%llX\n",
1764 (uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
1765 low = 0;
1766 high = pageHeader.entryCount();
1767 while (low < high) {
1768 uint32_t mid = (low + high) / 2;
1769 if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
1770 if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
1771 // at end of table
1772 low = mid;
1773 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1774 break;
1775 } else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
1776 // next is too big, so we found it
1777 low = mid;
1778 funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
1779 break;
1780 } else {
1781 low = mid + 1;
1782 }
1783 } else {
1784 high = mid;
1785 }
1786 }
1787 encoding = pageIndex.encoding(low);
1788 funcStart = pageIndex.functionOffset(low) + sects.dso_base;
1789 if (pc < funcStart) {
1790 if (log)
1791 fprintf(
1792 stderr,
1793 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1794 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1795 return false;
1796 }
1797 if (pc > funcEnd) {
1798 if (log)
1799 fprintf(
1800 stderr,
1801 "\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
1802 (uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
1803 return false;
1804 }
1805 } else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
1806 // compressed page
1807 UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
1808 secondLevelAddr);
1809 UnwindSectionCompressedArray<A> pageIndex(
1810 _addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
1811 const uint32_t targetFunctionPageOffset =
1812 (uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
1813 // binary search looks for entry with e where index[e].offset <= pc <
1814 // index[e+1].offset
1815 if (log)
1816 fprintf(stderr, "\tbinary search of compressed page starting at "
1817 "secondLevelAddr=0x%llX\n",
1818 (uint64_t) secondLevelAddr);
1819 low = 0;
1820 last = pageHeader.entryCount() - 1;
1821 high = pageHeader.entryCount();
1822 while (low < high) {
1823 uint32_t mid = (low + high) / 2;
1824 if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
1825 if ((mid == last) ||
1826 (pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
1827 low = mid;
1828 break;
1829 } else {
1830 low = mid + 1;
1831 }
1832 } else {
1833 high = mid;
1834 }
1835 }
1836 funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
1837 + sects.dso_base;
1838 if (low < last)
1839 funcEnd =
1840 pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
1841 + sects.dso_base;
1842 else
1843 funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
1844 if (pc < funcStart) {
1845 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1846 "not in second level compressed unwind table. "
1847 "funcStart=0x%llX",
1848 (uint64_t) pc, (uint64_t) funcStart);
1849 return false;
1850 }
1851 if (pc > funcEnd) {
1852 _LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
1853 "not in second level compressed unwind table. "
1854 "funcEnd=0x%llX",
1855 (uint64_t) pc, (uint64_t) funcEnd);
1856 return false;
1857 }
1858 uint16_t encodingIndex = pageIndex.encodingIndex(low);
1859 if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
1860 // encoding is in common table in section header
1861 encoding = _addressSpace.get32(
1862 sects.compact_unwind_section +
1863 sectionHeader.commonEncodingsArraySectionOffset() +
1864 encodingIndex * sizeof(uint32_t));
1865 } else {
1866 // encoding is in page specific table
1867 uint16_t pageEncodingIndex =
1868 encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
1869 encoding = _addressSpace.get32(secondLevelAddr +
1870 pageHeader.encodingsPageOffset() +
1871 pageEncodingIndex * sizeof(uint32_t));
1872 }
1873 } else {
1874 _LIBUNWIND_DEBUG_LOG(
1875 "malformed __unwind_info at 0x%0llX bad second level page",
1876 (uint64_t)sects.compact_unwind_section);
1877 return false;
1878 }
1879
1880 // look up LSDA, if encoding says function has one
1881 if (encoding & UNWIND_HAS_LSDA) {
1882 UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
1883 uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
1884 low = 0;
1885 high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
1886 sizeof(unwind_info_section_header_lsda_index_entry);
1887 // binary search looks for entry with exact match for functionOffset
1888 if (log)
1889 fprintf(stderr,
1890 "\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
1891 funcStartOffset);
1892 while (low < high) {
1893 uint32_t mid = (low + high) / 2;
1894 if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
1895 lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
1896 break;
1897 } else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
1898 low = mid + 1;
1899 } else {
1900 high = mid;
1901 }
1902 }
1903 if (lsda == 0) {
1904 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
1905 "pc=0x%0llX, but lsda table has no entry",
1906 encoding, (uint64_t) pc);
1907 return false;
1908 }
1909 }
1910
1911 // extract personality routine, if encoding says function has one
1912 uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
1913 (__builtin_ctz(UNWIND_PERSONALITY_MASK));
1914 if (personalityIndex != 0) {
1915 --personalityIndex; // change 1-based to zero-based index
1916 if (personalityIndex >= sectionHeader.personalityArrayCount()) {
1917 _LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
1918 "but personality table has only %d entries",
1919 encoding, personalityIndex,
1920 sectionHeader.personalityArrayCount());
1921 return false;
1922 }
1923 int32_t personalityDelta = (int32_t)_addressSpace.get32(
1924 sects.compact_unwind_section +
1925 sectionHeader.personalityArraySectionOffset() +
1926 personalityIndex * sizeof(uint32_t));
1927 pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
1928 personality = _addressSpace.getP(personalityPointer);
1929 if (log)
1930 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1931 "personalityDelta=0x%08X, personality=0x%08llX\n",
1932 (uint64_t) pc, personalityDelta, (uint64_t) personality);
1933 }
1934
1935 if (log)
1936 fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
1937 "encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
1938 (uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
1939 _info.start_ip = funcStart;
1940 _info.end_ip = funcEnd;
1941 _info.lsda = lsda;
1942 _info.handler = personality;
1943 _info.gp = 0;
1944 _info.flags = 0;
1945 _info.format = encoding;
1946 _info.unwind_info = 0;
1947 _info.unwind_info_size = 0;
1948 _info.extra = sects.dso_base;
1949 return true;
1950 }
1951 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
1952
1953
1954 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
1955 template <typename A, typename R>
getInfoFromSEH(pint_t pc)1956 bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
1957 pint_t base;
1958 RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
1959 if (!unwindEntry) {
1960 _LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
1961 return false;
1962 }
1963 _info.gp = 0;
1964 _info.flags = 0;
1965 _info.format = 0;
1966 _info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
1967 _info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
1968 _info.extra = base;
1969 _info.start_ip = base + unwindEntry->BeginAddress;
1970 #ifdef _LIBUNWIND_TARGET_X86_64
1971 _info.end_ip = base + unwindEntry->EndAddress;
1972 // Only fill in the handler and LSDA if they're stale.
1973 if (pc != getLastPC()) {
1974 UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
1975 if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
1976 // The personality is given in the UNWIND_INFO itself. The LSDA immediately
1977 // follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
1978 // these structures.)
1979 // N.B. UNWIND_INFO structs are DWORD-aligned.
1980 uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
1981 const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
1982 _info.lsda = reinterpret_cast<unw_word_t>(handler+1);
1983 if (*handler) {
1984 _info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
1985 } else
1986 _info.handler = 0;
1987 } else {
1988 _info.lsda = 0;
1989 _info.handler = 0;
1990 }
1991 }
1992 #endif
1993 setLastPC(pc);
1994 return true;
1995 }
1996 #endif
1997
1998 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
1999 // Masks for traceback table field xtbtable.
2000 enum xTBTableMask : uint8_t {
2001 reservedBit = 0x02, // The traceback table was incorrectly generated if set
2002 // (see comments in function getInfoFromTBTable().
2003 ehInfoBit = 0x08 // Exception handling info is present if set
2004 };
2005
2006 enum frameType : unw_word_t {
2007 frameWithXLEHStateTable = 0,
2008 frameWithEHInfo = 1
2009 };
2010
2011 extern "C" {
2012 typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
2013 uint64_t,
2014 _Unwind_Exception *,
2015 struct _Unwind_Context *);
2016 __attribute__((__weak__)) __xlcxx_personality_v0_t __xlcxx_personality_v0;
2017 }
2018
2019 static __xlcxx_personality_v0_t *xlcPersonalityV0;
2020 static RWMutex xlcPersonalityV0InitLock;
2021
2022 template <typename A, typename R>
getInfoFromTBTable(pint_t pc,R & registers)2023 bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R ®isters) {
2024 uint32_t *p = reinterpret_cast<uint32_t *>(pc);
2025
2026 // Keep looking forward until a word of 0 is found. The traceback
2027 // table starts at the following word.
2028 while (*p)
2029 ++p;
2030 tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
2031
2032 if (_LIBUNWIND_TRACING_UNWINDING) {
2033 char functionBuf[512];
2034 const char *functionName = functionBuf;
2035 unw_word_t offset;
2036 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2037 functionName = ".anonymous.";
2038 }
2039 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2040 __func__, functionName,
2041 reinterpret_cast<void *>(TBTable));
2042 }
2043
2044 // If the traceback table does not contain necessary info, bypass this frame.
2045 if (!TBTable->tb.has_tboff)
2046 return false;
2047
2048 // Structure tbtable_ext contains important data we are looking for.
2049 p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2050
2051 // Skip field parminfo if it exists.
2052 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2053 ++p;
2054
2055 // p now points to tb_offset, the offset from start of function to TB table.
2056 unw_word_t start_ip =
2057 reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
2058 unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
2059 ++p;
2060
2061 _LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
2062 reinterpret_cast<void *>(start_ip),
2063 reinterpret_cast<void *>(end_ip));
2064
2065 // Skip field hand_mask if it exists.
2066 if (TBTable->tb.int_hndl)
2067 ++p;
2068
2069 unw_word_t lsda = 0;
2070 unw_word_t handler = 0;
2071 unw_word_t flags = frameType::frameWithXLEHStateTable;
2072
2073 if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
2074 // State table info is available. The ctl_info field indicates the
2075 // number of CTL anchors. There should be only one entry for the C++
2076 // state table.
2077 assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
2078 ++p;
2079 // p points to the offset of the state table into the stack.
2080 pint_t stateTableOffset = *p++;
2081
2082 int framePointerReg;
2083
2084 // Skip fields name_len and name if exist.
2085 if (TBTable->tb.name_present) {
2086 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
2087 p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
2088 sizeof(uint16_t));
2089 }
2090
2091 if (TBTable->tb.uses_alloca)
2092 framePointerReg = *(reinterpret_cast<char *>(p));
2093 else
2094 framePointerReg = 1; // default frame pointer == SP
2095
2096 _LIBUNWIND_TRACE_UNWINDING(
2097 "framePointerReg=%d, framePointer=%p, "
2098 "stateTableOffset=%#lx\n",
2099 framePointerReg,
2100 reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
2101 stateTableOffset);
2102 lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
2103
2104 // Since the traceback table generated by the legacy XLC++ does not
2105 // provide the location of the personality for the state table,
2106 // function __xlcxx_personality_v0(), which is the personality for the state
2107 // table and is exported from libc++abi, is directly assigned as the
2108 // handler here. When a legacy XLC++ frame is encountered, the symbol
2109 // is resolved dynamically using dlopen() to avoid hard dependency from
2110 // libunwind on libc++abi.
2111
2112 // Resolve the function pointer to the state table personality if it has
2113 // not already.
2114 if (xlcPersonalityV0 == NULL) {
2115 xlcPersonalityV0InitLock.lock();
2116 if (xlcPersonalityV0 == NULL) {
2117 // If libc++abi is statically linked in, symbol __xlcxx_personality_v0
2118 // has been resolved at the link time.
2119 xlcPersonalityV0 = &__xlcxx_personality_v0;
2120 if (xlcPersonalityV0 == NULL) {
2121 // libc++abi is dynamically linked. Resolve __xlcxx_personality_v0
2122 // using dlopen().
2123 const char libcxxabi[] = "libc++abi.a(libc++abi.so.1)";
2124 void *libHandle;
2125 // The AIX dlopen() sets errno to 0 when it is successful, which
2126 // clobbers the value of errno from the user code. This is an AIX
2127 // bug because according to POSIX it should not set errno to 0. To
2128 // workaround before AIX fixes the bug, errno is saved and restored.
2129 int saveErrno = errno;
2130 libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
2131 if (libHandle == NULL) {
2132 _LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n",
2133 errno);
2134 assert(0 && "dlopen() failed");
2135 }
2136 xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
2137 dlsym(libHandle, "__xlcxx_personality_v0"));
2138 if (xlcPersonalityV0 == NULL) {
2139 _LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
2140 assert(0 && "dlsym() failed");
2141 }
2142 dlclose(libHandle);
2143 errno = saveErrno;
2144 }
2145 }
2146 xlcPersonalityV0InitLock.unlock();
2147 }
2148 handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
2149 _LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
2150 reinterpret_cast<void *>(lsda),
2151 reinterpret_cast<void *>(handler));
2152 } else if (TBTable->tb.longtbtable) {
2153 // This frame has the traceback table extension. Possible cases are
2154 // 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
2155 // is not EH aware; or, 3) a frame of other languages. We need to figure out
2156 // if the traceback table extension contains the 'eh_info' structure.
2157 //
2158 // We also need to deal with the complexity arising from some XL compiler
2159 // versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
2160 // where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
2161 // versa. For frames of code generated by those compilers, the 'longtbtable'
2162 // bit may be set but there isn't really a traceback table extension.
2163 //
2164 // In </usr/include/sys/debug.h>, there is the following definition of
2165 // 'struct tbtable_ext'. It is not really a structure but a dummy to
2166 // collect the description of optional parts of the traceback table.
2167 //
2168 // struct tbtable_ext {
2169 // ...
2170 // char alloca_reg; /* Register for alloca automatic storage */
2171 // struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
2172 // unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
2173 // };
2174 //
2175 // Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
2176 // following 'alloca_reg' can be treated either as 'struct vec_ext' or
2177 // 'unsigned char xtbtable'. 'xtbtable' bits are defined in
2178 // </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
2179 // unused and should not be set. 'struct vec_ext' is defined in
2180 // </usr/include/sys/debug.h> as follows:
2181 //
2182 // struct vec_ext {
2183 // unsigned vr_saved:6; /* Number of non-volatile vector regs saved
2184 // */
2185 // /* first register saved is assumed to be */
2186 // /* 32 - vr_saved */
2187 // unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */
2188 // unsigned has_varargs:1;
2189 // ...
2190 // };
2191 //
2192 // Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
2193 // is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
2194 // we checks if the 7th bit is set or not because 'xtbtable' should
2195 // never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
2196 // in the future to make sure the mitigation works. This mitigation
2197 // is not 100% bullet proof because 'struct vec_ext' may not always have
2198 // 'saves_vrsave' bit set.
2199 //
2200 // 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
2201 // checking the 7th bit.
2202
2203 // p points to field name len.
2204 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2205
2206 // Skip fields name_len and name if they exist.
2207 if (TBTable->tb.name_present) {
2208 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2209 charPtr = charPtr + name_len + sizeof(uint16_t);
2210 }
2211
2212 // Skip field alloc_reg if it exists.
2213 if (TBTable->tb.uses_alloca)
2214 ++charPtr;
2215
2216 // Check traceback table bit has_vec. Skip struct vec_ext if it exists.
2217 if (TBTable->tb.has_vec)
2218 // Note struct vec_ext does exist at this point because whether the
2219 // ordering of longtbtable and has_vec bits is correct or not, both
2220 // are set.
2221 charPtr += sizeof(struct vec_ext);
2222
2223 // charPtr points to field 'xtbtable'. Check if the EH info is available.
2224 // Also check if the reserved bit of the extended traceback table field
2225 // 'xtbtable' is set. If it is, the traceback table was incorrectly
2226 // generated by an XL compiler that uses the wrong ordering of 'longtbtable'
2227 // and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
2228 // frame.
2229 if ((*charPtr & xTBTableMask::ehInfoBit) &&
2230 !(*charPtr & xTBTableMask::reservedBit)) {
2231 // Mark this frame has the new EH info.
2232 flags = frameType::frameWithEHInfo;
2233
2234 // eh_info is available.
2235 charPtr++;
2236 // The pointer is 4-byte aligned.
2237 if (reinterpret_cast<uintptr_t>(charPtr) % 4)
2238 charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
2239 uintptr_t *ehInfo =
2240 reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
2241 registers.getRegister(2) +
2242 *(reinterpret_cast<uintptr_t *>(charPtr)))));
2243
2244 // ehInfo points to structure en_info. The first member is version.
2245 // Only version 0 is currently supported.
2246 assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
2247 "libunwind: ehInfo version other than 0 is not supported");
2248
2249 // Increment ehInfo to point to member lsda.
2250 ++ehInfo;
2251 lsda = *ehInfo++;
2252
2253 // enInfo now points to member personality.
2254 handler = *ehInfo;
2255
2256 _LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
2257 lsda, handler);
2258 }
2259 }
2260
2261 _info.start_ip = start_ip;
2262 _info.end_ip = end_ip;
2263 _info.lsda = lsda;
2264 _info.handler = handler;
2265 _info.gp = 0;
2266 _info.flags = flags;
2267 _info.format = 0;
2268 _info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
2269 _info.unwind_info_size = 0;
2270 _info.extra = registers.getRegister(2);
2271
2272 return true;
2273 }
2274
2275 // Step back up the stack following the frame back link.
2276 template <typename A, typename R>
stepWithTBTable(pint_t pc,tbtable * TBTable,R & registers,bool & isSignalFrame)2277 int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
2278 R ®isters, bool &isSignalFrame) {
2279 if (_LIBUNWIND_TRACING_UNWINDING) {
2280 char functionBuf[512];
2281 const char *functionName = functionBuf;
2282 unw_word_t offset;
2283 if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
2284 functionName = ".anonymous.";
2285 }
2286 _LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
2287 __func__, functionName,
2288 reinterpret_cast<void *>(TBTable));
2289 }
2290
2291 #if defined(__powerpc64__)
2292 // Instruction to reload TOC register "l r2,40(r1)"
2293 const uint32_t loadTOCRegInst = 0xe8410028;
2294 const int32_t unwPPCF0Index = UNW_PPC64_F0;
2295 const int32_t unwPPCV0Index = UNW_PPC64_V0;
2296 #else
2297 // Instruction to reload TOC register "l r2,20(r1)"
2298 const uint32_t loadTOCRegInst = 0x80410014;
2299 const int32_t unwPPCF0Index = UNW_PPC_F0;
2300 const int32_t unwPPCV0Index = UNW_PPC_V0;
2301 #endif
2302
2303 R newRegisters = registers;
2304
2305 // lastStack points to the stack frame of the next routine up.
2306 pint_t lastStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2307
2308 // Return address is the address after call site instruction.
2309 pint_t returnAddress;
2310
2311 if (isSignalFrame) {
2312 _LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
2313 reinterpret_cast<void *>(lastStack));
2314
2315 sigcontext *sigContext = reinterpret_cast<sigcontext *>(
2316 reinterpret_cast<char *>(lastStack) + STKMIN);
2317 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2318
2319 _LIBUNWIND_TRACE_UNWINDING("From sigContext=%p, returnAddress=%p\n",
2320 reinterpret_cast<void *>(sigContext),
2321 reinterpret_cast<void *>(returnAddress));
2322
2323 if (returnAddress < 0x10000000) {
2324 // Try again using STKMINALIGN
2325 sigContext = reinterpret_cast<sigcontext *>(
2326 reinterpret_cast<char *>(lastStack) + STKMINALIGN);
2327 returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
2328 if (returnAddress < 0x10000000) {
2329 _LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p\n",
2330 reinterpret_cast<void *>(returnAddress));
2331 return UNW_EBADFRAME;
2332 } else {
2333 _LIBUNWIND_TRACE_UNWINDING("Tried again using STKMINALIGN: "
2334 "sigContext=%p, returnAddress=%p. "
2335 "Seems to be a valid address\n",
2336 reinterpret_cast<void *>(sigContext),
2337 reinterpret_cast<void *>(returnAddress));
2338 }
2339 }
2340 // Restore the condition register from sigcontext.
2341 newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
2342
2343 // Restore GPRs from sigcontext.
2344 for (int i = 0; i < 32; ++i)
2345 newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
2346
2347 // Restore FPRs from sigcontext.
2348 for (int i = 0; i < 32; ++i)
2349 newRegisters.setFloatRegister(i + unwPPCF0Index,
2350 sigContext->sc_jmpbuf.jmp_context.fpr[i]);
2351
2352 // Restore vector registers if there is an associated extended context
2353 // structure.
2354 if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
2355 ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
2356 if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
2357 for (int i = 0; i < 32; ++i)
2358 newRegisters.setVectorRegister(
2359 i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
2360 &(uContext->__extctx->__vmx.__vr[i]))));
2361 }
2362 }
2363 } else {
2364 // Step up a normal frame.
2365 returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
2366
2367 _LIBUNWIND_TRACE_UNWINDING("Extract info from lastStack=%p, "
2368 "returnAddress=%p\n",
2369 reinterpret_cast<void *>(lastStack),
2370 reinterpret_cast<void *>(returnAddress));
2371 _LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d\n",
2372 TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
2373 TBTable->tb.saves_cr);
2374
2375 // Restore FP registers.
2376 char *ptrToRegs = reinterpret_cast<char *>(lastStack);
2377 double *FPRegs = reinterpret_cast<double *>(
2378 ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
2379 for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
2380 newRegisters.setFloatRegister(
2381 32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
2382
2383 // Restore GP registers.
2384 ptrToRegs = reinterpret_cast<char *>(FPRegs);
2385 uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
2386 ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
2387 for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
2388 newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
2389
2390 // Restore Vector registers.
2391 ptrToRegs = reinterpret_cast<char *>(GPRegs);
2392
2393 // Restore vector registers only if this is a Clang frame. Also
2394 // check if traceback table bit has_vec is set. If it is, structure
2395 // vec_ext is available.
2396 if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
2397
2398 // Get to the vec_ext structure to check if vector registers are saved.
2399 uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
2400
2401 // Skip field parminfo if exists.
2402 if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
2403 ++p;
2404
2405 // Skip field tb_offset if exists.
2406 if (TBTable->tb.has_tboff)
2407 ++p;
2408
2409 // Skip field hand_mask if exists.
2410 if (TBTable->tb.int_hndl)
2411 ++p;
2412
2413 // Skip fields ctl_info and ctl_info_disp if exist.
2414 if (TBTable->tb.has_ctl) {
2415 // Skip field ctl_info.
2416 ++p;
2417 // Skip field ctl_info_disp.
2418 ++p;
2419 }
2420
2421 // Skip fields name_len and name if exist.
2422 // p is supposed to point to field name_len now.
2423 uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
2424 if (TBTable->tb.name_present) {
2425 const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
2426 charPtr = charPtr + name_len + sizeof(uint16_t);
2427 }
2428
2429 // Skip field alloc_reg if it exists.
2430 if (TBTable->tb.uses_alloca)
2431 ++charPtr;
2432
2433 struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
2434
2435 _LIBUNWIND_TRACE_UNWINDING("vr_saved=%d\n", vec_ext->vr_saved);
2436
2437 // Restore vector register(s) if saved on the stack.
2438 if (vec_ext->vr_saved) {
2439 // Saved vector registers are 16-byte aligned.
2440 if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
2441 ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
2442 v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
2443 sizeof(v128));
2444 for (int i = 0; i < vec_ext->vr_saved; ++i) {
2445 newRegisters.setVectorRegister(
2446 32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
2447 }
2448 }
2449 }
2450 if (TBTable->tb.saves_cr) {
2451 // Get the saved condition register. The condition register is only
2452 // a single word.
2453 newRegisters.setCR(
2454 *(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
2455 }
2456
2457 // Restore the SP.
2458 newRegisters.setSP(lastStack);
2459
2460 // The first instruction after return.
2461 uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
2462
2463 // Do we need to set the TOC register?
2464 _LIBUNWIND_TRACE_UNWINDING(
2465 "Current gpr2=%p\n",
2466 reinterpret_cast<void *>(newRegisters.getRegister(2)));
2467 if (firstInstruction == loadTOCRegInst) {
2468 _LIBUNWIND_TRACE_UNWINDING(
2469 "Set gpr2=%p from frame\n",
2470 reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
2471 newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
2472 }
2473 }
2474 _LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
2475 reinterpret_cast<void *>(lastStack),
2476 reinterpret_cast<void *>(returnAddress),
2477 reinterpret_cast<void *>(pc));
2478
2479 // The return address is the address after call site instruction, so
2480 // setting IP to that simulates a return.
2481 newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
2482
2483 // Simulate the step by replacing the register set with the new ones.
2484 registers = newRegisters;
2485
2486 // Check if the next frame is a signal frame.
2487 pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
2488
2489 // Return address is the address after call site instruction.
2490 pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
2491
2492 if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
2493 _LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
2494 "nextStack=%p, next return address=%p\n",
2495 reinterpret_cast<void *>(nextStack),
2496 reinterpret_cast<void *>(nextReturnAddress));
2497 isSignalFrame = true;
2498 } else {
2499 isSignalFrame = false;
2500 }
2501
2502 return UNW_STEP_SUCCESS;
2503 }
2504 #endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2505
2506 template <typename A, typename R>
setInfoBasedOnIPRegister(bool isReturnAddress)2507 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
2508 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2509 _isSigReturn = false;
2510 #endif
2511
2512 pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2513 #if defined(_LIBUNWIND_ARM_EHABI)
2514 // Remove the thumb bit so the IP represents the actual instruction address.
2515 // This matches the behaviour of _Unwind_GetIP on arm.
2516 pc &= (pint_t)~0x1;
2517 #endif
2518
2519 // Exit early if at the top of the stack.
2520 if (pc == 0) {
2521 _unwindInfoMissing = true;
2522 return;
2523 }
2524
2525 // If the last line of a function is a "throw" the compiler sometimes
2526 // emits no instructions after the call to __cxa_throw. This means
2527 // the return address is actually the start of the next function.
2528 // To disambiguate this, back up the pc when we know it is a return
2529 // address.
2530 if (isReturnAddress)
2531 #if defined(_AIX)
2532 // PC needs to be a 4-byte aligned address to be able to look for a
2533 // word of 0 that indicates the start of the traceback table at the end
2534 // of a function on AIX.
2535 pc -= 4;
2536 #else
2537 --pc;
2538 #endif
2539
2540 // Ask address space object to find unwind sections for this pc.
2541 UnwindInfoSections sects;
2542 bool have_sects = false;
2543 if (uwis_cache.getUnwindInfoSectionsForPC(pc, sects))
2544 have_sects = true;
2545 else if (_addressSpace.findUnwindSections(pc, sects)) {
2546 uwis_cache.setUnwindInfoSectionsForPC(pc, sects);
2547 have_sects = true;
2548 }
2549 if (have_sects) {
2550 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2551 // If there is a compact unwind encoding table, look there first.
2552 if (sects.compact_unwind_section != 0) {
2553 if (this->getInfoFromCompactEncodingSection(pc, sects)) {
2554 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2555 // Found info in table, done unless encoding says to use dwarf.
2556 uint32_t dwarfOffset;
2557 if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
2558 if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
2559 // found info in dwarf, done
2560 return;
2561 }
2562 }
2563 #endif
2564 // If unwind table has entry, but entry says there is no unwind info,
2565 // record that we have no unwind info.
2566 if (_info.format == 0)
2567 _unwindInfoMissing = true;
2568 return;
2569 }
2570 }
2571 #endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2572
2573 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2574 // If there is SEH unwind info, look there next.
2575 if (this->getInfoFromSEH(pc))
2576 return;
2577 #endif
2578
2579 #if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2580 // If there is unwind info in the traceback table, look there next.
2581 if (this->getInfoFromTBTable(pc, _registers))
2582 return;
2583 #endif
2584
2585 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2586 // If there is dwarf unwind info, look there next.
2587 if (sects.dwarf_section != 0) {
2588 if (this->getInfoFromDwarfSection(pc, sects)) {
2589 // found info in dwarf, done
2590 return;
2591 }
2592 }
2593 #endif
2594
2595 #if defined(_LIBUNWIND_ARM_EHABI)
2596 // If there is ARM EHABI unwind info, look there next.
2597 if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
2598 return;
2599 #endif
2600 }
2601
2602 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2603 // There is no static unwind info for this pc. Look to see if an FDE was
2604 // dynamically registered for it.
2605 pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
2606 pc);
2607 if (cachedFDE != 0) {
2608 typename CFI_Parser<A>::FDE_Info fdeInfo;
2609 typename CFI_Parser<A>::CIE_Info cieInfo;
2610 if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
2611 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2612 return;
2613 }
2614
2615 // Lastly, ask AddressSpace object about platform specific ways to locate
2616 // other FDEs.
2617 pint_t fde;
2618 if (_addressSpace.findOtherFDE(pc, fde)) {
2619 typename CFI_Parser<A>::FDE_Info fdeInfo;
2620 typename CFI_Parser<A>::CIE_Info cieInfo;
2621 if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
2622 // Double check this FDE is for a function that includes the pc.
2623 if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
2624 if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
2625 return;
2626 }
2627 }
2628 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2629
2630 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2631 if (setInfoForSigReturn())
2632 return;
2633 #endif
2634
2635 // no unwind info, flag that we can't reliably unwind
2636 _unwindInfoMissing = true;
2637 }
2638
2639 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2640 defined(_LIBUNWIND_TARGET_AARCH64)
2641 template <typename A, typename R>
setInfoForSigReturn(Registers_arm64 &)2642 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
2643 // Look for the sigreturn trampoline. The trampoline's body is two
2644 // specific instructions (see below). Typically the trampoline comes from the
2645 // vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
2646 // own restorer function, though, or user-mode QEMU might write a trampoline
2647 // onto the stack.
2648 //
2649 // This special code path is a fallback that is only used if the trampoline
2650 // lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
2651 // constant for the PC needs to be defined before DWARF can handle a signal
2652 // trampoline. This code may segfault if the target PC is unreadable, e.g.:
2653 // - The PC points at a function compiled without unwind info, and which is
2654 // part of an execute-only mapping (e.g. using -Wl,--execute-only).
2655 // - The PC is invalid and happens to point to unreadable or unmapped memory.
2656 //
2657 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
2658 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2659 // The PC might contain an invalid address if the unwind info is bad, so
2660 // directly accessing it could cause a segfault. Use process_vm_readv to read
2661 // the memory safely instead. process_vm_readv was added in Linux 3.2, and
2662 // AArch64 supported was added in Linux 3.7, so the syscall is guaranteed to
2663 // be present. Unfortunately, there are Linux AArch64 environments where the
2664 // libc wrapper for the syscall might not be present (e.g. Android 5), so call
2665 // the syscall directly instead.
2666 uint32_t instructions[2];
2667 struct iovec local_iov = {&instructions, sizeof instructions};
2668 struct iovec remote_iov = {reinterpret_cast<void *>(pc), sizeof instructions};
2669 long bytesRead =
2670 syscall(SYS_process_vm_readv, getpid(), &local_iov, 1, &remote_iov, 1, 0);
2671 // Look for instructions: mov x8, #0x8b; svc #0x0
2672 if (bytesRead != sizeof instructions || instructions[0] != 0xd2801168 ||
2673 instructions[1] != 0xd4000001)
2674 return false;
2675
2676 _info = {};
2677 _info.start_ip = pc;
2678 _info.end_ip = pc + 4;
2679 _isSigReturn = true;
2680 return true;
2681 }
2682
2683 template <typename A, typename R>
stepThroughSigReturn(Registers_arm64 &)2684 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
2685 // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
2686 // - 128-byte siginfo struct
2687 // - ucontext struct:
2688 // - 8-byte long (uc_flags)
2689 // - 8-byte pointer (uc_link)
2690 // - 24-byte stack_t
2691 // - 128-byte signal set
2692 // - 8 bytes of padding because sigcontext has 16-byte alignment
2693 // - sigcontext/mcontext_t
2694 // [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
2695 const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
2696
2697 // Offsets from sigcontext to each register.
2698 const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
2699 const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
2700 const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
2701
2702 pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
2703
2704 for (int i = 0; i <= 30; ++i) {
2705 uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
2706 static_cast<pint_t>(i * 8));
2707 _registers.setRegister(UNW_AARCH64_X0 + i, value);
2708 }
2709 _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
2710 _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
2711 _isSignalFrame = true;
2712 return UNW_STEP_SUCCESS;
2713 }
2714 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2715 // defined(_LIBUNWIND_TARGET_AARCH64)
2716
2717 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) && \
2718 defined(_LIBUNWIND_TARGET_S390X)
2719 template <typename A, typename R>
setInfoForSigReturn(Registers_s390x &)2720 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
2721 // Look for the sigreturn trampoline. The trampoline's body is a
2722 // specific instruction (see below). Typically the trampoline comes from the
2723 // vDSO (i.e. the __kernel_[rt_]sigreturn function). A libc might provide its
2724 // own restorer function, though, or user-mode QEMU might write a trampoline
2725 // onto the stack.
2726 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2727 // The PC might contain an invalid address if the unwind info is bad, so
2728 // directly accessing it could cause a segfault. Use process_vm_readv to
2729 // read the memory safely instead.
2730 uint16_t inst;
2731 struct iovec local_iov = {&inst, sizeof inst};
2732 struct iovec remote_iov = {reinterpret_cast<void *>(pc), sizeof inst};
2733 long bytesRead = process_vm_readv(getpid(), &local_iov, 1, &remote_iov, 1, 0);
2734 if (bytesRead == sizeof inst && (inst == 0x0a77 || inst == 0x0aad)) {
2735 _info = {};
2736 _info.start_ip = pc;
2737 _info.end_ip = pc + 2;
2738 _isSigReturn = true;
2739 return true;
2740 }
2741 return false;
2742 }
2743
2744 template <typename A, typename R>
stepThroughSigReturn(Registers_s390x &)2745 int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
2746 // Determine current SP.
2747 const pint_t sp = static_cast<pint_t>(this->getReg(UNW_REG_SP));
2748 // According to the s390x ABI, the CFA is at (incoming) SP + 160.
2749 const pint_t cfa = sp + 160;
2750
2751 // Determine current PC and instruction there (this must be either
2752 // a "svc __NR_sigreturn" or "svc __NR_rt_sigreturn").
2753 const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
2754 const uint16_t inst = _addressSpace.get16(pc);
2755
2756 // Find the addresses of the signo and sigcontext in the frame.
2757 pint_t pSigctx = 0;
2758 pint_t pSigno = 0;
2759
2760 // "svc __NR_sigreturn" uses a non-RT signal trampoline frame.
2761 if (inst == 0x0a77) {
2762 // Layout of a non-RT signal trampoline frame, starting at the CFA:
2763 // - 8-byte signal mask
2764 // - 8-byte pointer to sigcontext, followed by signo
2765 // - 4-byte signo
2766 pSigctx = _addressSpace.get64(cfa + 8);
2767 pSigno = pSigctx + 344;
2768 }
2769
2770 // "svc __NR_rt_sigreturn" uses a RT signal trampoline frame.
2771 if (inst == 0x0aad) {
2772 // Layout of a RT signal trampoline frame, starting at the CFA:
2773 // - 8-byte retcode (+ alignment)
2774 // - 128-byte siginfo struct (starts with signo)
2775 // - ucontext struct:
2776 // - 8-byte long (uc_flags)
2777 // - 8-byte pointer (uc_link)
2778 // - 24-byte stack_t
2779 // - 8 bytes of padding because sigcontext has 16-byte alignment
2780 // - sigcontext/mcontext_t
2781 pSigctx = cfa + 8 + 128 + 8 + 8 + 24 + 8;
2782 pSigno = cfa + 8;
2783 }
2784
2785 assert(pSigctx != 0);
2786 assert(pSigno != 0);
2787
2788 // Offsets from sigcontext to each register.
2789 const pint_t kOffsetPc = 8;
2790 const pint_t kOffsetGprs = 16;
2791 const pint_t kOffsetFprs = 216;
2792
2793 // Restore all registers.
2794 for (int i = 0; i < 16; ++i) {
2795 uint64_t value = _addressSpace.get64(pSigctx + kOffsetGprs +
2796 static_cast<pint_t>(i * 8));
2797 _registers.setRegister(UNW_S390X_R0 + i, value);
2798 }
2799 for (int i = 0; i < 16; ++i) {
2800 static const int fpr[16] = {
2801 UNW_S390X_F0, UNW_S390X_F1, UNW_S390X_F2, UNW_S390X_F3,
2802 UNW_S390X_F4, UNW_S390X_F5, UNW_S390X_F6, UNW_S390X_F7,
2803 UNW_S390X_F8, UNW_S390X_F9, UNW_S390X_F10, UNW_S390X_F11,
2804 UNW_S390X_F12, UNW_S390X_F13, UNW_S390X_F14, UNW_S390X_F15
2805 };
2806 double value = _addressSpace.getDouble(pSigctx + kOffsetFprs +
2807 static_cast<pint_t>(i * 8));
2808 _registers.setFloatRegister(fpr[i], value);
2809 }
2810 _registers.setIP(_addressSpace.get64(pSigctx + kOffsetPc));
2811
2812 // SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
2813 // after the faulting instruction rather than before it.
2814 // Do not set _isSignalFrame in that case.
2815 uint32_t signo = _addressSpace.get32(pSigno);
2816 _isSignalFrame = (signo != 4 && signo != 5 && signo != 8);
2817
2818 return UNW_STEP_SUCCESS;
2819 }
2820 #endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
2821 // defined(_LIBUNWIND_TARGET_S390X)
2822
step(bool stage2)2823 template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
2824 (void)stage2;
2825 // Bottom of stack is defined is when unwind info cannot be found.
2826 if (_unwindInfoMissing)
2827 return UNW_STEP_END;
2828
2829 // Use unwinding info to modify register set as if function returned.
2830 int result;
2831 #if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
2832 if (_isSigReturn) {
2833 result = this->stepThroughSigReturn();
2834 } else
2835 #endif
2836 {
2837 #if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
2838 result = this->stepWithCompactEncoding(stage2);
2839 #elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
2840 result = this->stepWithSEHData();
2841 #elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
2842 result = this->stepWithTBTableData();
2843 #elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
2844 result = this->stepWithDwarfFDE(stage2);
2845 #elif defined(_LIBUNWIND_ARM_EHABI)
2846 result = this->stepWithEHABI();
2847 #else
2848 #error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
2849 _LIBUNWIND_SUPPORT_SEH_UNWIND or \
2850 _LIBUNWIND_SUPPORT_DWARF_UNWIND or \
2851 _LIBUNWIND_ARM_EHABI
2852 #endif
2853 }
2854
2855 // update info based on new PC
2856 if (result == UNW_STEP_SUCCESS) {
2857 this->setInfoBasedOnIPRegister(true);
2858 if (_unwindInfoMissing)
2859 return UNW_STEP_END;
2860 }
2861
2862 return result;
2863 }
2864
2865 template <typename A, typename R>
getInfo(unw_proc_info_t * info)2866 void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
2867 if (_unwindInfoMissing)
2868 memset(info, 0, sizeof(*info));
2869 else
2870 *info = _info;
2871 }
2872
2873 template <typename A, typename R>
getFunctionName(char * buf,size_t bufLen,unw_word_t * offset)2874 bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
2875 unw_word_t *offset) {
2876 return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
2877 buf, bufLen, offset);
2878 }
2879
2880 #if defined(_LIBUNWIND_USE_CET)
__libunwind_cet_get_registers(unw_cursor_t * cursor)2881 extern "C" void *__libunwind_cet_get_registers(unw_cursor_t *cursor) {
2882 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
2883 return co->get_registers();
2884 }
2885 #endif
2886 } // namespace libunwind
2887
2888 #endif // __UNWINDCURSOR_HPP__
2889