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clang-p2996/libunwind/src/UnwindCursor.hpp
Xing Xue a85da649b9 [libunwind][AIX] implementation of the unwinder for AIX 
Summary:
This patch contains the implementation of the unwinder for IBM AIX.

AIX does not support the eh_frame section. Instead, the traceback table located at the end of each function provides the information for stack unwinding and EH. In this patch macro _LIBUNWIND_SUPPORT_TBTAB_UNWIND is used to guard code for AIX traceback table based unwinding. Function getInfoFromTBTable() and stepWithTBTable() are added to get the EH information from the traceback table and to step up the stack respectively.

There are two kinds of LSDA information for EH on AIX, the state table and the range table. The state table is used by the previous version of the IBM XL compiler, i.e., xlC and xlclang++. The DWARF based range table is used by AIX clang++. The traceback table has flags to differentiate these cases. For the range table, relative addresses are calculated using a base of DW_EH_PE_datarel, which is the TOC base of the module where the function of the current frame belongs.

Two personality routines are employed to handle these two different LSDAs, __xlcxx_personality_v0() for the state table and __xlcxx_personality_v1() for the range table. Since the traceback table does not have the information of the personality for the state table approach, its personality __xlcxx_personality_v0() is dynamically resolved as the handler for the state table. For the range table, the locations of the LSDA and its associated personality routine are found in the traceback table.

Assembly code for 32- and 64-bit PowerPC in UnwindRegistersRestore.S and UnwindRegistersSave.S are modified so that it can be consumed by the GNU flavor assembler and the AIX assembler. The restoration of vector registers does not check VRSAVE on AIX because VRSAVE is not used in the AIX ABI.

Reviewed by: MaskRay, compnerd, cebowleratibm, sfertile, libunwind

Differential Revision: https://reviews.llvm.org/D100132
2022-04-13 11:01:59 -04:00

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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//
// C++ interface to lower levels of libunwind
//===----------------------------------------------------------------------===//
#ifndef __UNWINDCURSOR_HPP__
#define __UNWINDCURSOR_HPP__
#include "cet_unwind.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unwind.h>
#ifdef _WIN32
#include <windows.h>
#include <ntverp.h>
#endif
#ifdef __APPLE__
#include <mach-o/dyld.h>
#endif
#ifdef _AIX
#include <dlfcn.h>
#include <sys/debug.h>
#include <sys/pseg.h>
#endif
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
// Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
// earlier) SDKs.
// MinGW-w64 has always provided this struct.
#if defined(_WIN32) && defined(_LIBUNWIND_TARGET_X86_64) && \
!defined(__MINGW32__) && VER_PRODUCTBUILD < 8000
struct _DISPATCHER_CONTEXT {
ULONG64 ControlPc;
ULONG64 ImageBase;
PRUNTIME_FUNCTION FunctionEntry;
ULONG64 EstablisherFrame;
ULONG64 TargetIp;
PCONTEXT ContextRecord;
PEXCEPTION_ROUTINE LanguageHandler;
PVOID HandlerData;
PUNWIND_HISTORY_TABLE HistoryTable;
ULONG ScopeIndex;
ULONG Fill0;
};
#endif
struct UNWIND_INFO {
uint8_t Version : 3;
uint8_t Flags : 5;
uint8_t SizeOfProlog;
uint8_t CountOfCodes;
uint8_t FrameRegister : 4;
uint8_t FrameOffset : 4;
uint16_t UnwindCodes[2];
};
extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
int, _Unwind_Action, uint64_t, _Unwind_Exception *,
struct _Unwind_Context *);
#endif
#include "config.h"
#include "AddressSpace.hpp"
#include "CompactUnwinder.hpp"
#include "config.h"
#include "DwarfInstructions.hpp"
#include "EHHeaderParser.hpp"
#include "libunwind.h"
#include "Registers.hpp"
#include "RWMutex.hpp"
#include "Unwind-EHABI.h"
namespace libunwind {
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
/// Cache of recently found FDEs.
template <typename A>
class _LIBUNWIND_HIDDEN DwarfFDECache {
typedef typename A::pint_t pint_t;
public:
static constexpr pint_t kSearchAll = static_cast<pint_t>(-1);
static pint_t findFDE(pint_t mh, pint_t pc);
static void add(pint_t mh, pint_t ip_start, pint_t ip_end, pint_t fde);
static void removeAllIn(pint_t mh);
static void iterateCacheEntries(void (*func)(unw_word_t ip_start,
unw_word_t ip_end,
unw_word_t fde, unw_word_t mh));
private:
struct entry {
pint_t mh;
pint_t ip_start;
pint_t ip_end;
pint_t fde;
};
// These fields are all static to avoid needing an initializer.
// There is only one instance of this class per process.
static RWMutex _lock;
#ifdef __APPLE__
static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
static bool _registeredForDyldUnloads;
#endif
static entry *_buffer;
static entry *_bufferUsed;
static entry *_bufferEnd;
static entry _initialBuffer[64];
};
template <typename A>
typename DwarfFDECache<A>::entry *
DwarfFDECache<A>::_buffer = _initialBuffer;
template <typename A>
typename DwarfFDECache<A>::entry *
DwarfFDECache<A>::_bufferUsed = _initialBuffer;
template <typename A>
typename DwarfFDECache<A>::entry *
DwarfFDECache<A>::_bufferEnd = &_initialBuffer[64];
template <typename A>
typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
template <typename A>
RWMutex DwarfFDECache<A>::_lock;
#ifdef __APPLE__
template <typename A>
bool DwarfFDECache<A>::_registeredForDyldUnloads = false;
#endif
template <typename A>
typename A::pint_t DwarfFDECache<A>::findFDE(pint_t mh, pint_t pc) {
pint_t result = 0;
_LIBUNWIND_LOG_IF_FALSE(_lock.lock_shared());
for (entry *p = _buffer; p < _bufferUsed; ++p) {
if ((mh == p->mh) || (mh == kSearchAll)) {
if ((p->ip_start <= pc) && (pc < p->ip_end)) {
result = p->fde;
break;
}
}
}
_LIBUNWIND_LOG_IF_FALSE(_lock.unlock_shared());
return result;
}
template <typename A>
void DwarfFDECache<A>::add(pint_t mh, pint_t ip_start, pint_t ip_end,
pint_t fde) {
#if !defined(_LIBUNWIND_NO_HEAP)
_LIBUNWIND_LOG_IF_FALSE(_lock.lock());
if (_bufferUsed >= _bufferEnd) {
size_t oldSize = (size_t)(_bufferEnd - _buffer);
size_t newSize = oldSize * 4;
// Can't use operator new (we are below it).
entry *newBuffer = (entry *)malloc(newSize * sizeof(entry));
memcpy(newBuffer, _buffer, oldSize * sizeof(entry));
if (_buffer != _initialBuffer)
free(_buffer);
_buffer = newBuffer;
_bufferUsed = &newBuffer[oldSize];
_bufferEnd = &newBuffer[newSize];
}
_bufferUsed->mh = mh;
_bufferUsed->ip_start = ip_start;
_bufferUsed->ip_end = ip_end;
_bufferUsed->fde = fde;
++_bufferUsed;
#ifdef __APPLE__
if (!_registeredForDyldUnloads) {
_dyld_register_func_for_remove_image(&dyldUnloadHook);
_registeredForDyldUnloads = true;
}
#endif
_LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
#endif
}
template <typename A>
void DwarfFDECache<A>::removeAllIn(pint_t mh) {
_LIBUNWIND_LOG_IF_FALSE(_lock.lock());
entry *d = _buffer;
for (const entry *s = _buffer; s < _bufferUsed; ++s) {
if (s->mh != mh) {
if (d != s)
*d = *s;
++d;
}
}
_bufferUsed = d;
_LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
}
#ifdef __APPLE__
template <typename A>
void DwarfFDECache<A>::dyldUnloadHook(const struct mach_header *mh, intptr_t ) {
removeAllIn((pint_t) mh);
}
#endif
template <typename A>
void DwarfFDECache<A>::iterateCacheEntries(void (*func)(
unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
_LIBUNWIND_LOG_IF_FALSE(_lock.lock());
for (entry *p = _buffer; p < _bufferUsed; ++p) {
(*func)(p->ip_start, p->ip_end, p->fde, p->mh);
}
_LIBUNWIND_LOG_IF_FALSE(_lock.unlock());
}
#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
#define arrayoffsetof(type, index, field) ((size_t)(&((type *)0)[index].field))
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
template <typename A> class UnwindSectionHeader {
public:
UnwindSectionHeader(A &addressSpace, typename A::pint_t addr)
: _addressSpace(addressSpace), _addr(addr) {}
uint32_t version() const {
return _addressSpace.get32(_addr +
offsetof(unwind_info_section_header, version));
}
uint32_t commonEncodingsArraySectionOffset() const {
return _addressSpace.get32(_addr +
offsetof(unwind_info_section_header,
commonEncodingsArraySectionOffset));
}
uint32_t commonEncodingsArrayCount() const {
return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
commonEncodingsArrayCount));
}
uint32_t personalityArraySectionOffset() const {
return _addressSpace.get32(_addr + offsetof(unwind_info_section_header,
personalityArraySectionOffset));
}
uint32_t personalityArrayCount() const {
return _addressSpace.get32(
_addr + offsetof(unwind_info_section_header, personalityArrayCount));
}
uint32_t indexSectionOffset() const {
return _addressSpace.get32(
_addr + offsetof(unwind_info_section_header, indexSectionOffset));
}
uint32_t indexCount() const {
return _addressSpace.get32(
_addr + offsetof(unwind_info_section_header, indexCount));
}
private:
A &_addressSpace;
typename A::pint_t _addr;
};
template <typename A> class UnwindSectionIndexArray {
public:
UnwindSectionIndexArray(A &addressSpace, typename A::pint_t addr)
: _addressSpace(addressSpace), _addr(addr) {}
uint32_t functionOffset(uint32_t index) const {
return _addressSpace.get32(
_addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
functionOffset));
}
uint32_t secondLevelPagesSectionOffset(uint32_t index) const {
return _addressSpace.get32(
_addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
secondLevelPagesSectionOffset));
}
uint32_t lsdaIndexArraySectionOffset(uint32_t index) const {
return _addressSpace.get32(
_addr + arrayoffsetof(unwind_info_section_header_index_entry, index,
lsdaIndexArraySectionOffset));
}
private:
A &_addressSpace;
typename A::pint_t _addr;
};
template <typename A> class UnwindSectionRegularPageHeader {
public:
UnwindSectionRegularPageHeader(A &addressSpace, typename A::pint_t addr)
: _addressSpace(addressSpace), _addr(addr) {}
uint32_t kind() const {
return _addressSpace.get32(
_addr + offsetof(unwind_info_regular_second_level_page_header, kind));
}
uint16_t entryPageOffset() const {
return _addressSpace.get16(
_addr + offsetof(unwind_info_regular_second_level_page_header,
entryPageOffset));
}
uint16_t entryCount() const {
return _addressSpace.get16(
_addr +
offsetof(unwind_info_regular_second_level_page_header, entryCount));
}
private:
A &_addressSpace;
typename A::pint_t _addr;
};
template <typename A> class UnwindSectionRegularArray {
public:
UnwindSectionRegularArray(A &addressSpace, typename A::pint_t addr)
: _addressSpace(addressSpace), _addr(addr) {}
uint32_t functionOffset(uint32_t index) const {
return _addressSpace.get32(
_addr + arrayoffsetof(unwind_info_regular_second_level_entry, index,
functionOffset));
}
uint32_t encoding(uint32_t index) const {
return _addressSpace.get32(
_addr +
arrayoffsetof(unwind_info_regular_second_level_entry, index, encoding));
}
private:
A &_addressSpace;
typename A::pint_t _addr;
};
template <typename A> class UnwindSectionCompressedPageHeader {
public:
UnwindSectionCompressedPageHeader(A &addressSpace, typename A::pint_t addr)
: _addressSpace(addressSpace), _addr(addr) {}
uint32_t kind() const {
return _addressSpace.get32(
_addr +
offsetof(unwind_info_compressed_second_level_page_header, kind));
}
uint16_t entryPageOffset() const {
return _addressSpace.get16(
_addr + offsetof(unwind_info_compressed_second_level_page_header,
entryPageOffset));
}
uint16_t entryCount() const {
return _addressSpace.get16(
_addr +
offsetof(unwind_info_compressed_second_level_page_header, entryCount));
}
uint16_t encodingsPageOffset() const {
return _addressSpace.get16(
_addr + offsetof(unwind_info_compressed_second_level_page_header,
encodingsPageOffset));
}
uint16_t encodingsCount() const {
return _addressSpace.get16(
_addr + offsetof(unwind_info_compressed_second_level_page_header,
encodingsCount));
}
private:
A &_addressSpace;
typename A::pint_t _addr;
};
template <typename A> class UnwindSectionCompressedArray {
public:
UnwindSectionCompressedArray(A &addressSpace, typename A::pint_t addr)
: _addressSpace(addressSpace), _addr(addr) {}
uint32_t functionOffset(uint32_t index) const {
return UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(
_addressSpace.get32(_addr + index * sizeof(uint32_t)));
}
uint16_t encodingIndex(uint32_t index) const {
return UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(
_addressSpace.get32(_addr + index * sizeof(uint32_t)));
}
private:
A &_addressSpace;
typename A::pint_t _addr;
};
template <typename A> class UnwindSectionLsdaArray {
public:
UnwindSectionLsdaArray(A &addressSpace, typename A::pint_t addr)
: _addressSpace(addressSpace), _addr(addr) {}
uint32_t functionOffset(uint32_t index) const {
return _addressSpace.get32(
_addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
index, functionOffset));
}
uint32_t lsdaOffset(uint32_t index) const {
return _addressSpace.get32(
_addr + arrayoffsetof(unwind_info_section_header_lsda_index_entry,
index, lsdaOffset));
}
private:
A &_addressSpace;
typename A::pint_t _addr;
};
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
class _LIBUNWIND_HIDDEN AbstractUnwindCursor {
public:
// NOTE: provide a class specific placement deallocation function (S5.3.4 p20)
// This avoids an unnecessary dependency to libc++abi.
void operator delete(void *, size_t) {}
virtual ~AbstractUnwindCursor() {}
virtual bool validReg(int) { _LIBUNWIND_ABORT("validReg not implemented"); }
virtual unw_word_t getReg(int) { _LIBUNWIND_ABORT("getReg not implemented"); }
virtual void setReg(int, unw_word_t) {
_LIBUNWIND_ABORT("setReg not implemented");
}
virtual bool validFloatReg(int) {
_LIBUNWIND_ABORT("validFloatReg not implemented");
}
virtual unw_fpreg_t getFloatReg(int) {
_LIBUNWIND_ABORT("getFloatReg not implemented");
}
virtual void setFloatReg(int, unw_fpreg_t) {
_LIBUNWIND_ABORT("setFloatReg not implemented");
}
virtual int step() { _LIBUNWIND_ABORT("step not implemented"); }
virtual void getInfo(unw_proc_info_t *) {
_LIBUNWIND_ABORT("getInfo not implemented");
}
virtual void jumpto() { _LIBUNWIND_ABORT("jumpto not implemented"); }
virtual bool isSignalFrame() {
_LIBUNWIND_ABORT("isSignalFrame not implemented");
}
virtual bool getFunctionName(char *, size_t, unw_word_t *) {
_LIBUNWIND_ABORT("getFunctionName not implemented");
}
virtual void setInfoBasedOnIPRegister(bool = false) {
_LIBUNWIND_ABORT("setInfoBasedOnIPRegister not implemented");
}
virtual const char *getRegisterName(int) {
_LIBUNWIND_ABORT("getRegisterName not implemented");
}
#ifdef __arm__
virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
#endif
#ifdef _AIX
virtual uintptr_t getDataRelBase() {
_LIBUNWIND_ABORT("getDataRelBase not implemented");
}
#endif
#if defined(_LIBUNWIND_USE_CET)
virtual void *get_registers() {
_LIBUNWIND_ABORT("get_registers not implemented");
}
#endif
};
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
/// \c UnwindCursor contains all state (including all register values) during
/// an unwind. This is normally stack-allocated inside a unw_cursor_t.
template <typename A, typename R>
class UnwindCursor : public AbstractUnwindCursor {
typedef typename A::pint_t pint_t;
public:
UnwindCursor(unw_context_t *context, A &as);
UnwindCursor(CONTEXT *context, A &as);
UnwindCursor(A &as, void *threadArg);
virtual ~UnwindCursor() {}
virtual bool validReg(int);
virtual unw_word_t getReg(int);
virtual void setReg(int, unw_word_t);
virtual bool validFloatReg(int);
virtual unw_fpreg_t getFloatReg(int);
virtual void setFloatReg(int, unw_fpreg_t);
virtual int step();
virtual void getInfo(unw_proc_info_t *);
virtual void jumpto();
virtual bool isSignalFrame();
virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
virtual const char *getRegisterName(int num);
#ifdef __arm__
virtual void saveVFPAsX();
#endif
DISPATCHER_CONTEXT *getDispatcherContext() { return &_dispContext; }
void setDispatcherContext(DISPATCHER_CONTEXT *disp) { _dispContext = *disp; }
// libunwind does not and should not depend on C++ library which means that we
// need our own defition of inline placement new.
static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
private:
pint_t getLastPC() const { return _dispContext.ControlPc; }
void setLastPC(pint_t pc) { _dispContext.ControlPc = pc; }
RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
_dispContext.FunctionEntry = RtlLookupFunctionEntry(pc,
&_dispContext.ImageBase,
_dispContext.HistoryTable);
*base = _dispContext.ImageBase;
return _dispContext.FunctionEntry;
}
bool getInfoFromSEH(pint_t pc);
int stepWithSEHData() {
_dispContext.LanguageHandler = RtlVirtualUnwind(UNW_FLAG_UHANDLER,
_dispContext.ImageBase,
_dispContext.ControlPc,
_dispContext.FunctionEntry,
_dispContext.ContextRecord,
&_dispContext.HandlerData,
&_dispContext.EstablisherFrame,
NULL);
// Update some fields of the unwind info now, since we have them.
_info.lsda = reinterpret_cast<unw_word_t>(_dispContext.HandlerData);
if (_dispContext.LanguageHandler) {
_info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
} else
_info.handler = 0;
return UNW_STEP_SUCCESS;
}
A &_addressSpace;
unw_proc_info_t _info;
DISPATCHER_CONTEXT _dispContext;
CONTEXT _msContext;
UNWIND_HISTORY_TABLE _histTable;
bool _unwindInfoMissing;
};
template <typename A, typename R>
UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
: _addressSpace(as), _unwindInfoMissing(false) {
static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
"UnwindCursor<> does not fit in unw_cursor_t");
static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
"UnwindCursor<> requires more alignment than unw_cursor_t");
memset(&_info, 0, sizeof(_info));
memset(&_histTable, 0, sizeof(_histTable));
_dispContext.ContextRecord = &_msContext;
_dispContext.HistoryTable = &_histTable;
// Initialize MS context from ours.
R r(context);
_msContext.ContextFlags = CONTEXT_CONTROL|CONTEXT_INTEGER|CONTEXT_FLOATING_POINT;
#if defined(_LIBUNWIND_TARGET_X86_64)
_msContext.Rax = r.getRegister(UNW_X86_64_RAX);
_msContext.Rcx = r.getRegister(UNW_X86_64_RCX);
_msContext.Rdx = r.getRegister(UNW_X86_64_RDX);
_msContext.Rbx = r.getRegister(UNW_X86_64_RBX);
_msContext.Rsp = r.getRegister(UNW_X86_64_RSP);
_msContext.Rbp = r.getRegister(UNW_X86_64_RBP);
_msContext.Rsi = r.getRegister(UNW_X86_64_RSI);
_msContext.Rdi = r.getRegister(UNW_X86_64_RDI);
_msContext.R8 = r.getRegister(UNW_X86_64_R8);
_msContext.R9 = r.getRegister(UNW_X86_64_R9);
_msContext.R10 = r.getRegister(UNW_X86_64_R10);
_msContext.R11 = r.getRegister(UNW_X86_64_R11);
_msContext.R12 = r.getRegister(UNW_X86_64_R12);
_msContext.R13 = r.getRegister(UNW_X86_64_R13);
_msContext.R14 = r.getRegister(UNW_X86_64_R14);
_msContext.R15 = r.getRegister(UNW_X86_64_R15);
_msContext.Rip = r.getRegister(UNW_REG_IP);
union {
v128 v;
M128A m;
} t;
t.v = r.getVectorRegister(UNW_X86_64_XMM0);
_msContext.Xmm0 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM1);
_msContext.Xmm1 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM2);
_msContext.Xmm2 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM3);
_msContext.Xmm3 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM4);
_msContext.Xmm4 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM5);
_msContext.Xmm5 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM6);
_msContext.Xmm6 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM7);
_msContext.Xmm7 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM8);
_msContext.Xmm8 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM9);
_msContext.Xmm9 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM10);
_msContext.Xmm10 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM11);
_msContext.Xmm11 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM12);
_msContext.Xmm12 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM13);
_msContext.Xmm13 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM14);
_msContext.Xmm14 = t.m;
t.v = r.getVectorRegister(UNW_X86_64_XMM15);
_msContext.Xmm15 = t.m;
#elif defined(_LIBUNWIND_TARGET_ARM)
_msContext.R0 = r.getRegister(UNW_ARM_R0);
_msContext.R1 = r.getRegister(UNW_ARM_R1);
_msContext.R2 = r.getRegister(UNW_ARM_R2);
_msContext.R3 = r.getRegister(UNW_ARM_R3);
_msContext.R4 = r.getRegister(UNW_ARM_R4);
_msContext.R5 = r.getRegister(UNW_ARM_R5);
_msContext.R6 = r.getRegister(UNW_ARM_R6);
_msContext.R7 = r.getRegister(UNW_ARM_R7);
_msContext.R8 = r.getRegister(UNW_ARM_R8);
_msContext.R9 = r.getRegister(UNW_ARM_R9);
_msContext.R10 = r.getRegister(UNW_ARM_R10);
_msContext.R11 = r.getRegister(UNW_ARM_R11);
_msContext.R12 = r.getRegister(UNW_ARM_R12);
_msContext.Sp = r.getRegister(UNW_ARM_SP);
_msContext.Lr = r.getRegister(UNW_ARM_LR);
_msContext.Pc = r.getRegister(UNW_ARM_IP);
for (int i = UNW_ARM_D0; i <= UNW_ARM_D31; ++i) {
union {
uint64_t w;
double d;
} d;
d.d = r.getFloatRegister(i);
_msContext.D[i - UNW_ARM_D0] = d.w;
}
#elif defined(_LIBUNWIND_TARGET_AARCH64)
for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
_msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
_msContext.Sp = r.getRegister(UNW_REG_SP);
_msContext.Pc = r.getRegister(UNW_REG_IP);
for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
_msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
#endif
}
template <typename A, typename R>
UnwindCursor<A, R>::UnwindCursor(CONTEXT *context, A &as)
: _addressSpace(as), _unwindInfoMissing(false) {
static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
"UnwindCursor<> does not fit in unw_cursor_t");
memset(&_info, 0, sizeof(_info));
memset(&_histTable, 0, sizeof(_histTable));
_dispContext.ContextRecord = &_msContext;
_dispContext.HistoryTable = &_histTable;
_msContext = *context;
}
template <typename A, typename R>
bool UnwindCursor<A, R>::validReg(int regNum) {
if (regNum == UNW_REG_IP || regNum == UNW_REG_SP) return true;
#if defined(_LIBUNWIND_TARGET_X86_64)
if (regNum >= UNW_X86_64_RAX && regNum <= UNW_X86_64_R15) return true;
#elif defined(_LIBUNWIND_TARGET_ARM)
if ((regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) ||
regNum == UNW_ARM_RA_AUTH_CODE)
return true;
#elif defined(_LIBUNWIND_TARGET_AARCH64)
if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
#endif
return false;
}
template <typename A, typename R>
unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
switch (regNum) {
#if defined(_LIBUNWIND_TARGET_X86_64)
case UNW_REG_IP: return _msContext.Rip;
case UNW_X86_64_RAX: return _msContext.Rax;
case UNW_X86_64_RDX: return _msContext.Rdx;
case UNW_X86_64_RCX: return _msContext.Rcx;
case UNW_X86_64_RBX: return _msContext.Rbx;
case UNW_REG_SP:
case UNW_X86_64_RSP: return _msContext.Rsp;
case UNW_X86_64_RBP: return _msContext.Rbp;
case UNW_X86_64_RSI: return _msContext.Rsi;
case UNW_X86_64_RDI: return _msContext.Rdi;
case UNW_X86_64_R8: return _msContext.R8;
case UNW_X86_64_R9: return _msContext.R9;
case UNW_X86_64_R10: return _msContext.R10;
case UNW_X86_64_R11: return _msContext.R11;
case UNW_X86_64_R12: return _msContext.R12;
case UNW_X86_64_R13: return _msContext.R13;
case UNW_X86_64_R14: return _msContext.R14;
case UNW_X86_64_R15: return _msContext.R15;
#elif defined(_LIBUNWIND_TARGET_ARM)
case UNW_ARM_R0: return _msContext.R0;
case UNW_ARM_R1: return _msContext.R1;
case UNW_ARM_R2: return _msContext.R2;
case UNW_ARM_R3: return _msContext.R3;
case UNW_ARM_R4: return _msContext.R4;
case UNW_ARM_R5: return _msContext.R5;
case UNW_ARM_R6: return _msContext.R6;
case UNW_ARM_R7: return _msContext.R7;
case UNW_ARM_R8: return _msContext.R8;
case UNW_ARM_R9: return _msContext.R9;
case UNW_ARM_R10: return _msContext.R10;
case UNW_ARM_R11: return _msContext.R11;
case UNW_ARM_R12: return _msContext.R12;
case UNW_REG_SP:
case UNW_ARM_SP: return _msContext.Sp;
case UNW_ARM_LR: return _msContext.Lr;
case UNW_REG_IP:
case UNW_ARM_IP: return _msContext.Pc;
#elif defined(_LIBUNWIND_TARGET_AARCH64)
case UNW_REG_SP: return _msContext.Sp;
case UNW_REG_IP: return _msContext.Pc;
default: return _msContext.X[regNum - UNW_AARCH64_X0];
#endif
}
_LIBUNWIND_ABORT("unsupported register");
}
template <typename A, typename R>
void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
switch (regNum) {
#if defined(_LIBUNWIND_TARGET_X86_64)
case UNW_REG_IP: _msContext.Rip = value; break;
case UNW_X86_64_RAX: _msContext.Rax = value; break;
case UNW_X86_64_RDX: _msContext.Rdx = value; break;
case UNW_X86_64_RCX: _msContext.Rcx = value; break;
case UNW_X86_64_RBX: _msContext.Rbx = value; break;
case UNW_REG_SP:
case UNW_X86_64_RSP: _msContext.Rsp = value; break;
case UNW_X86_64_RBP: _msContext.Rbp = value; break;
case UNW_X86_64_RSI: _msContext.Rsi = value; break;
case UNW_X86_64_RDI: _msContext.Rdi = value; break;
case UNW_X86_64_R8: _msContext.R8 = value; break;
case UNW_X86_64_R9: _msContext.R9 = value; break;
case UNW_X86_64_R10: _msContext.R10 = value; break;
case UNW_X86_64_R11: _msContext.R11 = value; break;
case UNW_X86_64_R12: _msContext.R12 = value; break;
case UNW_X86_64_R13: _msContext.R13 = value; break;
case UNW_X86_64_R14: _msContext.R14 = value; break;
case UNW_X86_64_R15: _msContext.R15 = value; break;
#elif defined(_LIBUNWIND_TARGET_ARM)
case UNW_ARM_R0: _msContext.R0 = value; break;
case UNW_ARM_R1: _msContext.R1 = value; break;
case UNW_ARM_R2: _msContext.R2 = value; break;
case UNW_ARM_R3: _msContext.R3 = value; break;
case UNW_ARM_R4: _msContext.R4 = value; break;
case UNW_ARM_R5: _msContext.R5 = value; break;
case UNW_ARM_R6: _msContext.R6 = value; break;
case UNW_ARM_R7: _msContext.R7 = value; break;
case UNW_ARM_R8: _msContext.R8 = value; break;
case UNW_ARM_R9: _msContext.R9 = value; break;
case UNW_ARM_R10: _msContext.R10 = value; break;
case UNW_ARM_R11: _msContext.R11 = value; break;
case UNW_ARM_R12: _msContext.R12 = value; break;
case UNW_REG_SP:
case UNW_ARM_SP: _msContext.Sp = value; break;
case UNW_ARM_LR: _msContext.Lr = value; break;
case UNW_REG_IP:
case UNW_ARM_IP: _msContext.Pc = value; break;
#elif defined(_LIBUNWIND_TARGET_AARCH64)
case UNW_REG_SP: _msContext.Sp = value; break;
case UNW_REG_IP: _msContext.Pc = value; break;
case UNW_AARCH64_X0:
case UNW_AARCH64_X1:
case UNW_AARCH64_X2:
case UNW_AARCH64_X3:
case UNW_AARCH64_X4:
case UNW_AARCH64_X5:
case UNW_AARCH64_X6:
case UNW_AARCH64_X7:
case UNW_AARCH64_X8:
case UNW_AARCH64_X9:
case UNW_AARCH64_X10:
case UNW_AARCH64_X11:
case UNW_AARCH64_X12:
case UNW_AARCH64_X13:
case UNW_AARCH64_X14:
case UNW_AARCH64_X15:
case UNW_AARCH64_X16:
case UNW_AARCH64_X17:
case UNW_AARCH64_X18:
case UNW_AARCH64_X19:
case UNW_AARCH64_X20:
case UNW_AARCH64_X21:
case UNW_AARCH64_X22:
case UNW_AARCH64_X23:
case UNW_AARCH64_X24:
case UNW_AARCH64_X25:
case UNW_AARCH64_X26:
case UNW_AARCH64_X27:
case UNW_AARCH64_X28:
case UNW_AARCH64_FP:
case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
#endif
default:
_LIBUNWIND_ABORT("unsupported register");
}
}
template <typename A, typename R>
bool UnwindCursor<A, R>::validFloatReg(int regNum) {
#if defined(_LIBUNWIND_TARGET_ARM)
if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
#elif defined(_LIBUNWIND_TARGET_AARCH64)
if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
#else
(void)regNum;
#endif
return false;
}
template <typename A, typename R>
unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
#if defined(_LIBUNWIND_TARGET_ARM)
if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
union {
uint32_t w;
float f;
} d;
d.w = _msContext.S[regNum - UNW_ARM_S0];
return d.f;
}
if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
union {
uint64_t w;
double d;
} d;
d.w = _msContext.D[regNum - UNW_ARM_D0];
return d.d;
}
_LIBUNWIND_ABORT("unsupported float register");
#elif defined(_LIBUNWIND_TARGET_AARCH64)
return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
#else
(void)regNum;
_LIBUNWIND_ABORT("float registers unimplemented");
#endif
}
template <typename A, typename R>
void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
#if defined(_LIBUNWIND_TARGET_ARM)
if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) {
union {
uint32_t w;
float f;
} d;
d.f = value;
_msContext.S[regNum - UNW_ARM_S0] = d.w;
}
if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {
union {
uint64_t w;
double d;
} d;
d.d = value;
_msContext.D[regNum - UNW_ARM_D0] = d.w;
}
_LIBUNWIND_ABORT("unsupported float register");
#elif defined(_LIBUNWIND_TARGET_AARCH64)
_msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
#else
(void)regNum;
(void)value;
_LIBUNWIND_ABORT("float registers unimplemented");
#endif
}
template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
RtlRestoreContext(&_msContext, nullptr);
}
#ifdef __arm__
template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {}
#endif
template <typename A, typename R>
const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
return R::getRegisterName(regNum);
}
template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
return false;
}
#else // !defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) || !defined(_WIN32)
/// UnwindCursor contains all state (including all register values) during
/// an unwind. This is normally stack allocated inside a unw_cursor_t.
template <typename A, typename R>
class UnwindCursor : public AbstractUnwindCursor{
typedef typename A::pint_t pint_t;
public:
UnwindCursor(unw_context_t *context, A &as);
UnwindCursor(A &as, void *threadArg);
virtual ~UnwindCursor() {}
virtual bool validReg(int);
virtual unw_word_t getReg(int);
virtual void setReg(int, unw_word_t);
virtual bool validFloatReg(int);
virtual unw_fpreg_t getFloatReg(int);
virtual void setFloatReg(int, unw_fpreg_t);
virtual int step();
virtual void getInfo(unw_proc_info_t *);
virtual void jumpto();
virtual bool isSignalFrame();
virtual bool getFunctionName(char *buf, size_t len, unw_word_t *off);
virtual void setInfoBasedOnIPRegister(bool isReturnAddress = false);
virtual const char *getRegisterName(int num);
#ifdef __arm__
virtual void saveVFPAsX();
#endif
#ifdef _AIX
virtual uintptr_t getDataRelBase();
#endif
#if defined(_LIBUNWIND_USE_CET)
virtual void *get_registers() { return &_registers; }
#endif
// libunwind does not and should not depend on C++ library which means that we
// need our own defition of inline placement new.
static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
private:
#if defined(_LIBUNWIND_ARM_EHABI)
bool getInfoFromEHABISection(pint_t pc, const UnwindInfoSections &sects);
int stepWithEHABI() {
size_t len = 0;
size_t off = 0;
// FIXME: Calling decode_eht_entry() here is violating the libunwind
// abstraction layer.
const uint32_t *ehtp =
decode_eht_entry(reinterpret_cast<const uint32_t *>(_info.unwind_info),
&off, &len);
if (_Unwind_VRS_Interpret((_Unwind_Context *)this, ehtp, off, len) !=
_URC_CONTINUE_UNWIND)
return UNW_STEP_END;
return UNW_STEP_SUCCESS;
}
#endif
#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
bool setInfoForSigReturn() {
R dummy;
return setInfoForSigReturn(dummy);
}
int stepThroughSigReturn() {
R dummy;
return stepThroughSigReturn(dummy);
}
bool setInfoForSigReturn(Registers_arm64 &);
int stepThroughSigReturn(Registers_arm64 &);
template <typename Registers> bool setInfoForSigReturn(Registers &) {
return false;
}
template <typename Registers> int stepThroughSigReturn(Registers &) {
return UNW_STEP_END;
}
#endif
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
bool getInfoFromFdeCie(const typename CFI_Parser<A>::FDE_Info &fdeInfo,
const typename CFI_Parser<A>::CIE_Info &cieInfo,
pint_t pc, uintptr_t dso_base);
bool getInfoFromDwarfSection(pint_t pc, const UnwindInfoSections &sects,
uint32_t fdeSectionOffsetHint=0);
int stepWithDwarfFDE() {
return DwarfInstructions<A, R>::stepWithDwarf(_addressSpace,
(pint_t)this->getReg(UNW_REG_IP),
(pint_t)_info.unwind_info,
_registers, _isSignalFrame);
}
#endif
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
bool getInfoFromCompactEncodingSection(pint_t pc,
const UnwindInfoSections &sects);
int stepWithCompactEncoding() {
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
if ( compactSaysUseDwarf() )
return stepWithDwarfFDE();
#endif
R dummy;
return stepWithCompactEncoding(dummy);
}
#if defined(_LIBUNWIND_TARGET_X86_64)
int stepWithCompactEncoding(Registers_x86_64 &) {
return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
_info.format, _info.start_ip, _addressSpace, _registers);
}
#endif
#if defined(_LIBUNWIND_TARGET_I386)
int stepWithCompactEncoding(Registers_x86 &) {
return CompactUnwinder_x86<A>::stepWithCompactEncoding(
_info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
}
#endif
#if defined(_LIBUNWIND_TARGET_PPC)
int stepWithCompactEncoding(Registers_ppc &) {
return UNW_EINVAL;
}
#endif
#if defined(_LIBUNWIND_TARGET_PPC64)
int stepWithCompactEncoding(Registers_ppc64 &) {
return UNW_EINVAL;
}
#endif
#if defined(_LIBUNWIND_TARGET_AARCH64)
int stepWithCompactEncoding(Registers_arm64 &) {
return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
_info.format, _info.start_ip, _addressSpace, _registers);
}
#endif
#if defined(_LIBUNWIND_TARGET_MIPS_O32)
int stepWithCompactEncoding(Registers_mips_o32 &) {
return UNW_EINVAL;
}
#endif
#if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
int stepWithCompactEncoding(Registers_mips_newabi &) {
return UNW_EINVAL;
}
#endif
#if defined(_LIBUNWIND_TARGET_SPARC)
int stepWithCompactEncoding(Registers_sparc &) { return UNW_EINVAL; }
#endif
#if defined(_LIBUNWIND_TARGET_SPARC64)
int stepWithCompactEncoding(Registers_sparc64 &) { return UNW_EINVAL; }
#endif
#if defined (_LIBUNWIND_TARGET_RISCV)
int stepWithCompactEncoding(Registers_riscv &) {
return UNW_EINVAL;
}
#endif
bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
R dummy;
return compactSaysUseDwarf(dummy, offset);
}
#if defined(_LIBUNWIND_TARGET_X86_64)
bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
if (offset)
*offset = (_info.format & UNWIND_X86_64_DWARF_SECTION_OFFSET);
return true;
}
return false;
}
#endif
#if defined(_LIBUNWIND_TARGET_I386)
bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
if (offset)
*offset = (_info.format & UNWIND_X86_DWARF_SECTION_OFFSET);
return true;
}
return false;
}
#endif
#if defined(_LIBUNWIND_TARGET_PPC)
bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
return true;
}
#endif
#if defined(_LIBUNWIND_TARGET_PPC64)
bool compactSaysUseDwarf(Registers_ppc64 &, uint32_t *) const {
return true;
}
#endif
#if defined(_LIBUNWIND_TARGET_AARCH64)
bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
if (offset)
*offset = (_info.format & UNWIND_ARM64_DWARF_SECTION_OFFSET);
return true;
}
return false;
}
#endif
#if defined(_LIBUNWIND_TARGET_MIPS_O32)
bool compactSaysUseDwarf(Registers_mips_o32 &, uint32_t *) const {
return true;
}
#endif
#if defined(_LIBUNWIND_TARGET_MIPS_NEWABI)
bool compactSaysUseDwarf(Registers_mips_newabi &, uint32_t *) const {
return true;
}
#endif
#if defined(_LIBUNWIND_TARGET_SPARC)
bool compactSaysUseDwarf(Registers_sparc &, uint32_t *) const { return true; }
#endif
#if defined(_LIBUNWIND_TARGET_SPARC64)
bool compactSaysUseDwarf(Registers_sparc64 &, uint32_t *) const {
return true;
}
#endif
#if defined (_LIBUNWIND_TARGET_RISCV)
bool compactSaysUseDwarf(Registers_riscv &, uint32_t *) const {
return true;
}
#endif
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
compact_unwind_encoding_t dwarfEncoding() const {
R dummy;
return dwarfEncoding(dummy);
}
#if defined(_LIBUNWIND_TARGET_X86_64)
compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
return UNWIND_X86_64_MODE_DWARF;
}
#endif
#if defined(_LIBUNWIND_TARGET_I386)
compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
return UNWIND_X86_MODE_DWARF;
}
#endif
#if defined(_LIBUNWIND_TARGET_PPC)
compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
return 0;
}
#endif
#if defined(_LIBUNWIND_TARGET_PPC64)
compact_unwind_encoding_t dwarfEncoding(Registers_ppc64 &) const {
return 0;
}
#endif
#if defined(_LIBUNWIND_TARGET_AARCH64)
compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
return UNWIND_ARM64_MODE_DWARF;
}
#endif
#if defined(_LIBUNWIND_TARGET_ARM)
compact_unwind_encoding_t dwarfEncoding(Registers_arm &) const {
return 0;
}
#endif
#if defined (_LIBUNWIND_TARGET_OR1K)
compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
return 0;
}
#endif
#if defined (_LIBUNWIND_TARGET_HEXAGON)
compact_unwind_encoding_t dwarfEncoding(Registers_hexagon &) const {
return 0;
}
#endif
#if defined (_LIBUNWIND_TARGET_MIPS_O32)
compact_unwind_encoding_t dwarfEncoding(Registers_mips_o32 &) const {
return 0;
}
#endif
#if defined (_LIBUNWIND_TARGET_MIPS_NEWABI)
compact_unwind_encoding_t dwarfEncoding(Registers_mips_newabi &) const {
return 0;
}
#endif
#if defined(_LIBUNWIND_TARGET_SPARC)
compact_unwind_encoding_t dwarfEncoding(Registers_sparc &) const { return 0; }
#endif
#if defined(_LIBUNWIND_TARGET_SPARC64)
compact_unwind_encoding_t dwarfEncoding(Registers_sparc64 &) const {
return 0;
}
#endif
#if defined (_LIBUNWIND_TARGET_RISCV)
compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
return 0;
}
#endif
#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
// For runtime environments using SEH unwind data without Windows runtime
// support.
pint_t getLastPC() const { /* FIXME: Implement */ return 0; }
void setLastPC(pint_t pc) { /* FIXME: Implement */ }
RUNTIME_FUNCTION *lookUpSEHUnwindInfo(pint_t pc, pint_t *base) {
/* FIXME: Implement */
*base = 0;
return nullptr;
}
bool getInfoFromSEH(pint_t pc);
int stepWithSEHData() { /* FIXME: Implement */ return 0; }
#endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
bool getInfoFromTBTable(pint_t pc, R &registers);
int stepWithTBTable(pint_t pc, tbtable *TBTable, R &registers,
bool &isSignalFrame);
int stepWithTBTableData() {
return stepWithTBTable(reinterpret_cast<pint_t>(this->getReg(UNW_REG_IP)),
reinterpret_cast<tbtable *>(_info.unwind_info),
_registers, _isSignalFrame);
}
#endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
A &_addressSpace;
R _registers;
unw_proc_info_t _info;
bool _unwindInfoMissing;
bool _isSignalFrame;
#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
bool _isSigReturn = false;
#endif
};
template <typename A, typename R>
UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
: _addressSpace(as), _registers(context), _unwindInfoMissing(false),
_isSignalFrame(false) {
static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
"UnwindCursor<> does not fit in unw_cursor_t");
static_assert((alignof(UnwindCursor<A, R>) <= alignof(unw_cursor_t)),
"UnwindCursor<> requires more alignment than unw_cursor_t");
memset(&_info, 0, sizeof(_info));
}
template <typename A, typename R>
UnwindCursor<A, R>::UnwindCursor(A &as, void *)
: _addressSpace(as), _unwindInfoMissing(false), _isSignalFrame(false) {
memset(&_info, 0, sizeof(_info));
// FIXME
// fill in _registers from thread arg
}
template <typename A, typename R>
bool UnwindCursor<A, R>::validReg(int regNum) {
return _registers.validRegister(regNum);
}
template <typename A, typename R>
unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
return _registers.getRegister(regNum);
}
template <typename A, typename R>
void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
_registers.setRegister(regNum, (typename A::pint_t)value);
}
template <typename A, typename R>
bool UnwindCursor<A, R>::validFloatReg(int regNum) {
return _registers.validFloatRegister(regNum);
}
template <typename A, typename R>
unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
return _registers.getFloatRegister(regNum);
}
template <typename A, typename R>
void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
_registers.setFloatRegister(regNum, value);
}
template <typename A, typename R> void UnwindCursor<A, R>::jumpto() {
_registers.jumpto();
}
#ifdef __arm__
template <typename A, typename R> void UnwindCursor<A, R>::saveVFPAsX() {
_registers.saveVFPAsX();
}
#endif
#ifdef _AIX
template <typename A, typename R>
uintptr_t UnwindCursor<A, R>::getDataRelBase() {
return reinterpret_cast<uintptr_t>(_info.extra);
}
#endif
template <typename A, typename R>
const char *UnwindCursor<A, R>::getRegisterName(int regNum) {
return _registers.getRegisterName(regNum);
}
template <typename A, typename R> bool UnwindCursor<A, R>::isSignalFrame() {
return _isSignalFrame;
}
#endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
#if defined(_LIBUNWIND_ARM_EHABI)
template<typename A>
struct EHABISectionIterator {
typedef EHABISectionIterator _Self;
typedef typename A::pint_t value_type;
typedef typename A::pint_t* pointer;
typedef typename A::pint_t& reference;
typedef size_t size_type;
typedef size_t difference_type;
static _Self begin(A& addressSpace, const UnwindInfoSections& sects) {
return _Self(addressSpace, sects, 0);
}
static _Self end(A& addressSpace, const UnwindInfoSections& sects) {
return _Self(addressSpace, sects,
sects.arm_section_length / sizeof(EHABIIndexEntry));
}
EHABISectionIterator(A& addressSpace, const UnwindInfoSections& sects, size_t i)
: _i(i), _addressSpace(&addressSpace), _sects(&sects) {}
_Self& operator++() { ++_i; return *this; }
_Self& operator+=(size_t a) { _i += a; return *this; }
_Self& operator--() { assert(_i > 0); --_i; return *this; }
_Self& operator-=(size_t a) { assert(_i >= a); _i -= a; return *this; }
_Self operator+(size_t a) { _Self out = *this; out._i += a; return out; }
_Self operator-(size_t a) { assert(_i >= a); _Self out = *this; out._i -= a; return out; }
size_t operator-(const _Self& other) const { return _i - other._i; }
bool operator==(const _Self& other) const {
assert(_addressSpace == other._addressSpace);
assert(_sects == other._sects);
return _i == other._i;
}
bool operator!=(const _Self& other) const {
assert(_addressSpace == other._addressSpace);
assert(_sects == other._sects);
return _i != other._i;
}
typename A::pint_t operator*() const { return functionAddress(); }
typename A::pint_t functionAddress() const {
typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
EHABIIndexEntry, _i, functionOffset);
return indexAddr + signExtendPrel31(_addressSpace->get32(indexAddr));
}
typename A::pint_t dataAddress() {
typename A::pint_t indexAddr = _sects->arm_section + arrayoffsetof(
EHABIIndexEntry, _i, data);
return indexAddr;
}
private:
size_t _i;
A* _addressSpace;
const UnwindInfoSections* _sects;
};
namespace {
template <typename A>
EHABISectionIterator<A> EHABISectionUpperBound(
EHABISectionIterator<A> first,
EHABISectionIterator<A> last,
typename A::pint_t value) {
size_t len = last - first;
while (len > 0) {
size_t l2 = len / 2;
EHABISectionIterator<A> m = first + l2;
if (value < *m) {
len = l2;
} else {
first = ++m;
len -= l2 + 1;
}
}
return first;
}
}
template <typename A, typename R>
bool UnwindCursor<A, R>::getInfoFromEHABISection(
pint_t pc,
const UnwindInfoSections &sects) {
EHABISectionIterator<A> begin =
EHABISectionIterator<A>::begin(_addressSpace, sects);
EHABISectionIterator<A> end =
EHABISectionIterator<A>::end(_addressSpace, sects);
if (begin == end)
return false;
EHABISectionIterator<A> itNextPC = EHABISectionUpperBound(begin, end, pc);
if (itNextPC == begin)
return false;
EHABISectionIterator<A> itThisPC = itNextPC - 1;
pint_t thisPC = itThisPC.functionAddress();
// If an exception is thrown from a function, corresponding to the last entry
// in the table, we don't really know the function extent and have to choose a
// value for nextPC. Choosing max() will allow the range check during trace to
// succeed.
pint_t nextPC = (itNextPC == end) ? UINTPTR_MAX : itNextPC.functionAddress();
pint_t indexDataAddr = itThisPC.dataAddress();
if (indexDataAddr == 0)
return false;
uint32_t indexData = _addressSpace.get32(indexDataAddr);
if (indexData == UNW_EXIDX_CANTUNWIND)
return false;
// If the high bit is set, the exception handling table entry is inline inside
// the index table entry on the second word (aka |indexDataAddr|). Otherwise,
// the table points at an offset in the exception handling table (section 5
// EHABI).
pint_t exceptionTableAddr;
uint32_t exceptionTableData;
bool isSingleWordEHT;
if (indexData & 0x80000000) {
exceptionTableAddr = indexDataAddr;
// TODO(ajwong): Should this data be 0?
exceptionTableData = indexData;
isSingleWordEHT = true;
} else {
exceptionTableAddr = indexDataAddr + signExtendPrel31(indexData);
exceptionTableData = _addressSpace.get32(exceptionTableAddr);
isSingleWordEHT = false;
}
// Now we know the 3 things:
// exceptionTableAddr -- exception handler table entry.
// exceptionTableData -- the data inside the first word of the eht entry.
// isSingleWordEHT -- whether the entry is in the index.
unw_word_t personalityRoutine = 0xbadf00d;
bool scope32 = false;
uintptr_t lsda;
// If the high bit in the exception handling table entry is set, the entry is
// in compact form (section 6.3 EHABI).
if (exceptionTableData & 0x80000000) {
// Grab the index of the personality routine from the compact form.
uint32_t choice = (exceptionTableData & 0x0f000000) >> 24;
uint32_t extraWords = 0;
switch (choice) {
case 0:
personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr0;
extraWords = 0;
scope32 = false;
lsda = isSingleWordEHT ? 0 : (exceptionTableAddr + 4);
break;
case 1:
personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr1;
extraWords = (exceptionTableData & 0x00ff0000) >> 16;
scope32 = false;
lsda = exceptionTableAddr + (extraWords + 1) * 4;
break;
case 2:
personalityRoutine = (unw_word_t) &__aeabi_unwind_cpp_pr2;
extraWords = (exceptionTableData & 0x00ff0000) >> 16;
scope32 = true;
lsda = exceptionTableAddr + (extraWords + 1) * 4;
break;
default:
_LIBUNWIND_ABORT("unknown personality routine");
return false;
}
if (isSingleWordEHT) {
if (extraWords != 0) {
_LIBUNWIND_ABORT("index inlined table detected but pr function "
"requires extra words");
return false;
}
}
} else {
pint_t personalityAddr =
exceptionTableAddr + signExtendPrel31(exceptionTableData);
personalityRoutine = personalityAddr;
// ARM EHABI # 6.2, # 9.2
//
// +---- ehtp
// v
// +--------------------------------------+
// | +--------+--------+--------+-------+ |
// | |0| prel31 to personalityRoutine | |
// | +--------+--------+--------+-------+ |
// | | N | unwind opcodes | | <-- UnwindData
// | +--------+--------+--------+-------+ |
// | | Word 2 unwind opcodes | |
// | +--------+--------+--------+-------+ |
// | ... |
// | +--------+--------+--------+-------+ |
// | | Word N unwind opcodes | |
// | +--------+--------+--------+-------+ |
// | | LSDA | | <-- lsda
// | | ... | |
// | +--------+--------+--------+-------+ |
// +--------------------------------------+
uint32_t *UnwindData = reinterpret_cast<uint32_t*>(exceptionTableAddr) + 1;
uint32_t FirstDataWord = *UnwindData;
size_t N = ((FirstDataWord >> 24) & 0xff);
size_t NDataWords = N + 1;
lsda = reinterpret_cast<uintptr_t>(UnwindData + NDataWords);
}
_info.start_ip = thisPC;
_info.end_ip = nextPC;
_info.handler = personalityRoutine;
_info.unwind_info = exceptionTableAddr;
_info.lsda = lsda;
// flags is pr_cache.additional. See EHABI #7.2 for definition of bit 0.
_info.flags = (isSingleWordEHT ? 1 : 0) | (scope32 ? 0x2 : 0); // Use enum?
return true;
}
#endif
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
template <typename A, typename R>
bool UnwindCursor<A, 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) {
typename CFI_Parser<A>::PrologInfo prolog;
if (CFI_Parser<A>::parseFDEInstructions(_addressSpace, fdeInfo, cieInfo, pc,
R::getArch(), &prolog)) {
// Save off parsed FDE info
_info.start_ip = fdeInfo.pcStart;
_info.end_ip = fdeInfo.pcEnd;
_info.lsda = fdeInfo.lsda;
_info.handler = cieInfo.personality;
// Some frameless functions need SP altered when resuming in function, so
// propagate spExtraArgSize.
_info.gp = prolog.spExtraArgSize;
_info.flags = 0;
_info.format = dwarfEncoding();
_info.unwind_info = fdeInfo.fdeStart;
_info.unwind_info_size = static_cast<uint32_t>(fdeInfo.fdeLength);
_info.extra = static_cast<unw_word_t>(dso_base);
return true;
}
return false;
}
template <typename A, typename R>
bool UnwindCursor<A, R>::getInfoFromDwarfSection(pint_t pc,
const UnwindInfoSections &sects,
uint32_t fdeSectionOffsetHint) {
typename CFI_Parser<A>::FDE_Info fdeInfo;
typename CFI_Parser<A>::CIE_Info cieInfo;
bool foundFDE = false;
bool foundInCache = false;
// If compact encoding table gave offset into dwarf section, go directly there
if (fdeSectionOffsetHint != 0) {
foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
sects.dwarf_section_length,
sects.dwarf_section + fdeSectionOffsetHint,
&fdeInfo, &cieInfo);
}
#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
if (!foundFDE && (sects.dwarf_index_section != 0)) {
foundFDE = EHHeaderParser<A>::findFDE(
_addressSpace, pc, sects.dwarf_index_section,
(uint32_t)sects.dwarf_index_section_length, &fdeInfo, &cieInfo);
}
#endif
if (!foundFDE) {
// otherwise, search cache of previously found FDEs.
pint_t cachedFDE = DwarfFDECache<A>::findFDE(sects.dso_base, pc);
if (cachedFDE != 0) {
foundFDE =
CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
sects.dwarf_section_length,
cachedFDE, &fdeInfo, &cieInfo);
foundInCache = foundFDE;
}
}
if (!foundFDE) {
// Still not found, do full scan of __eh_frame section.
foundFDE = CFI_Parser<A>::findFDE(_addressSpace, pc, sects.dwarf_section,
sects.dwarf_section_length, 0,
&fdeInfo, &cieInfo);
}
if (foundFDE) {
if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, sects.dso_base)) {
// Add to cache (to make next lookup faster) if we had no hint
// and there was no index.
if (!foundInCache && (fdeSectionOffsetHint == 0)) {
#if defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
if (sects.dwarf_index_section == 0)
#endif
DwarfFDECache<A>::add(sects.dso_base, fdeInfo.pcStart, fdeInfo.pcEnd,
fdeInfo.fdeStart);
}
return true;
}
}
//_LIBUNWIND_DEBUG_LOG("can't find/use FDE for pc=0x%llX", (uint64_t)pc);
return false;
}
#endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
template <typename A, typename R>
bool UnwindCursor<A, R>::getInfoFromCompactEncodingSection(pint_t pc,
const UnwindInfoSections &sects) {
const bool log = false;
if (log)
fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX, mh=0x%llX)\n",
(uint64_t)pc, (uint64_t)sects.dso_base);
const UnwindSectionHeader<A> sectionHeader(_addressSpace,
sects.compact_unwind_section);
if (sectionHeader.version() != UNWIND_SECTION_VERSION)
return false;
// do a binary search of top level index to find page with unwind info
pint_t targetFunctionOffset = pc - sects.dso_base;
const UnwindSectionIndexArray<A> topIndex(_addressSpace,
sects.compact_unwind_section
+ sectionHeader.indexSectionOffset());
uint32_t low = 0;
uint32_t high = sectionHeader.indexCount();
uint32_t last = high - 1;
while (low < high) {
uint32_t mid = (low + high) / 2;
//if ( log ) fprintf(stderr, "\tmid=%d, low=%d, high=%d, *mid=0x%08X\n",
//mid, low, high, topIndex.functionOffset(mid));
if (topIndex.functionOffset(mid) <= targetFunctionOffset) {
if ((mid == last) ||
(topIndex.functionOffset(mid + 1) > targetFunctionOffset)) {
low = mid;
break;
} else {
low = mid + 1;
}
} else {
high = mid;
}
}
const uint32_t firstLevelFunctionOffset = topIndex.functionOffset(low);
const uint32_t firstLevelNextPageFunctionOffset =
topIndex.functionOffset(low + 1);
const pint_t secondLevelAddr =
sects.compact_unwind_section + topIndex.secondLevelPagesSectionOffset(low);
const pint_t lsdaArrayStartAddr =
sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low);
const pint_t lsdaArrayEndAddr =
sects.compact_unwind_section + topIndex.lsdaIndexArraySectionOffset(low+1);
if (log)
fprintf(stderr, "\tfirst level search for result index=%d "
"to secondLevelAddr=0x%llX\n",
low, (uint64_t) secondLevelAddr);
// do a binary search of second level page index
uint32_t encoding = 0;
pint_t funcStart = 0;
pint_t funcEnd = 0;
pint_t lsda = 0;
pint_t personality = 0;
uint32_t pageKind = _addressSpace.get32(secondLevelAddr);
if (pageKind == UNWIND_SECOND_LEVEL_REGULAR) {
// regular page
UnwindSectionRegularPageHeader<A> pageHeader(_addressSpace,
secondLevelAddr);
UnwindSectionRegularArray<A> pageIndex(
_addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
// binary search looks for entry with e where index[e].offset <= pc <
// index[e+1].offset
if (log)
fprintf(stderr, "\tbinary search for targetFunctionOffset=0x%08llX in "
"regular page starting at secondLevelAddr=0x%llX\n",
(uint64_t) targetFunctionOffset, (uint64_t) secondLevelAddr);
low = 0;
high = pageHeader.entryCount();
while (low < high) {
uint32_t mid = (low + high) / 2;
if (pageIndex.functionOffset(mid) <= targetFunctionOffset) {
if (mid == (uint32_t)(pageHeader.entryCount() - 1)) {
// at end of table
low = mid;
funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
break;
} else if (pageIndex.functionOffset(mid + 1) > targetFunctionOffset) {
// next is too big, so we found it
low = mid;
funcEnd = pageIndex.functionOffset(low + 1) + sects.dso_base;
break;
} else {
low = mid + 1;
}
} else {
high = mid;
}
}
encoding = pageIndex.encoding(low);
funcStart = pageIndex.functionOffset(low) + sects.dso_base;
if (pc < funcStart) {
if (log)
fprintf(
stderr,
"\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
(uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
return false;
}
if (pc > funcEnd) {
if (log)
fprintf(
stderr,
"\tpc not in table, pc=0x%llX, funcStart=0x%llX, funcEnd=0x%llX\n",
(uint64_t) pc, (uint64_t) funcStart, (uint64_t) funcEnd);
return false;
}
} else if (pageKind == UNWIND_SECOND_LEVEL_COMPRESSED) {
// compressed page
UnwindSectionCompressedPageHeader<A> pageHeader(_addressSpace,
secondLevelAddr);
UnwindSectionCompressedArray<A> pageIndex(
_addressSpace, secondLevelAddr + pageHeader.entryPageOffset());
const uint32_t targetFunctionPageOffset =
(uint32_t)(targetFunctionOffset - firstLevelFunctionOffset);
// binary search looks for entry with e where index[e].offset <= pc <
// index[e+1].offset
if (log)
fprintf(stderr, "\tbinary search of compressed page starting at "
"secondLevelAddr=0x%llX\n",
(uint64_t) secondLevelAddr);
low = 0;
last = pageHeader.entryCount() - 1;
high = pageHeader.entryCount();
while (low < high) {
uint32_t mid = (low + high) / 2;
if (pageIndex.functionOffset(mid) <= targetFunctionPageOffset) {
if ((mid == last) ||
(pageIndex.functionOffset(mid + 1) > targetFunctionPageOffset)) {
low = mid;
break;
} else {
low = mid + 1;
}
} else {
high = mid;
}
}
funcStart = pageIndex.functionOffset(low) + firstLevelFunctionOffset
+ sects.dso_base;
if (low < last)
funcEnd =
pageIndex.functionOffset(low + 1) + firstLevelFunctionOffset
+ sects.dso_base;
else
funcEnd = firstLevelNextPageFunctionOffset + sects.dso_base;
if (pc < funcStart) {
_LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
"not in second level compressed unwind table. "
"funcStart=0x%llX",
(uint64_t) pc, (uint64_t) funcStart);
return false;
}
if (pc > funcEnd) {
_LIBUNWIND_DEBUG_LOG("malformed __unwind_info, pc=0x%llX "
"not in second level compressed unwind table. "
"funcEnd=0x%llX",
(uint64_t) pc, (uint64_t) funcEnd);
return false;
}
uint16_t encodingIndex = pageIndex.encodingIndex(low);
if (encodingIndex < sectionHeader.commonEncodingsArrayCount()) {
// encoding is in common table in section header
encoding = _addressSpace.get32(
sects.compact_unwind_section +
sectionHeader.commonEncodingsArraySectionOffset() +
encodingIndex * sizeof(uint32_t));
} else {
// encoding is in page specific table
uint16_t pageEncodingIndex =
encodingIndex - (uint16_t)sectionHeader.commonEncodingsArrayCount();
encoding = _addressSpace.get32(secondLevelAddr +
pageHeader.encodingsPageOffset() +
pageEncodingIndex * sizeof(uint32_t));
}
} else {
_LIBUNWIND_DEBUG_LOG(
"malformed __unwind_info at 0x%0llX bad second level page",
(uint64_t)sects.compact_unwind_section);
return false;
}
// look up LSDA, if encoding says function has one
if (encoding & UNWIND_HAS_LSDA) {
UnwindSectionLsdaArray<A> lsdaIndex(_addressSpace, lsdaArrayStartAddr);
uint32_t funcStartOffset = (uint32_t)(funcStart - sects.dso_base);
low = 0;
high = (uint32_t)(lsdaArrayEndAddr - lsdaArrayStartAddr) /
sizeof(unwind_info_section_header_lsda_index_entry);
// binary search looks for entry with exact match for functionOffset
if (log)
fprintf(stderr,
"\tbinary search of lsda table for targetFunctionOffset=0x%08X\n",
funcStartOffset);
while (low < high) {
uint32_t mid = (low + high) / 2;
if (lsdaIndex.functionOffset(mid) == funcStartOffset) {
lsda = lsdaIndex.lsdaOffset(mid) + sects.dso_base;
break;
} else if (lsdaIndex.functionOffset(mid) < funcStartOffset) {
low = mid + 1;
} else {
high = mid;
}
}
if (lsda == 0) {
_LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with HAS_LSDA bit set for "
"pc=0x%0llX, but lsda table has no entry",
encoding, (uint64_t) pc);
return false;
}
}
// extract personality routine, if encoding says function has one
uint32_t personalityIndex = (encoding & UNWIND_PERSONALITY_MASK) >>
(__builtin_ctz(UNWIND_PERSONALITY_MASK));
if (personalityIndex != 0) {
--personalityIndex; // change 1-based to zero-based index
if (personalityIndex >= sectionHeader.personalityArrayCount()) {
_LIBUNWIND_DEBUG_LOG("found encoding 0x%08X with personality index %d, "
"but personality table has only %d entries",
encoding, personalityIndex,
sectionHeader.personalityArrayCount());
return false;
}
int32_t personalityDelta = (int32_t)_addressSpace.get32(
sects.compact_unwind_section +
sectionHeader.personalityArraySectionOffset() +
personalityIndex * sizeof(uint32_t));
pint_t personalityPointer = sects.dso_base + (pint_t)personalityDelta;
personality = _addressSpace.getP(personalityPointer);
if (log)
fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
"personalityDelta=0x%08X, personality=0x%08llX\n",
(uint64_t) pc, personalityDelta, (uint64_t) personality);
}
if (log)
fprintf(stderr, "getInfoFromCompactEncodingSection(pc=0x%llX), "
"encoding=0x%08X, lsda=0x%08llX for funcStart=0x%llX\n",
(uint64_t) pc, encoding, (uint64_t) lsda, (uint64_t) funcStart);
_info.start_ip = funcStart;
_info.end_ip = funcEnd;
_info.lsda = lsda;
_info.handler = personality;
_info.gp = 0;
_info.flags = 0;
_info.format = encoding;
_info.unwind_info = 0;
_info.unwind_info_size = 0;
_info.extra = sects.dso_base;
return true;
}
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
template <typename A, typename R>
bool UnwindCursor<A, R>::getInfoFromSEH(pint_t pc) {
pint_t base;
RUNTIME_FUNCTION *unwindEntry = lookUpSEHUnwindInfo(pc, &base);
if (!unwindEntry) {
_LIBUNWIND_DEBUG_LOG("\tpc not in table, pc=0x%llX", (uint64_t) pc);
return false;
}
_info.gp = 0;
_info.flags = 0;
_info.format = 0;
_info.unwind_info_size = sizeof(RUNTIME_FUNCTION);
_info.unwind_info = reinterpret_cast<unw_word_t>(unwindEntry);
_info.extra = base;
_info.start_ip = base + unwindEntry->BeginAddress;
#ifdef _LIBUNWIND_TARGET_X86_64
_info.end_ip = base + unwindEntry->EndAddress;
// Only fill in the handler and LSDA if they're stale.
if (pc != getLastPC()) {
UNWIND_INFO *xdata = reinterpret_cast<UNWIND_INFO *>(base + unwindEntry->UnwindData);
if (xdata->Flags & (UNW_FLAG_EHANDLER|UNW_FLAG_UHANDLER)) {
// The personality is given in the UNWIND_INFO itself. The LSDA immediately
// follows the UNWIND_INFO. (This follows how both Clang and MSVC emit
// these structures.)
// N.B. UNWIND_INFO structs are DWORD-aligned.
uint32_t lastcode = (xdata->CountOfCodes + 1) & ~1;
const uint32_t *handler = reinterpret_cast<uint32_t *>(&xdata->UnwindCodes[lastcode]);
_info.lsda = reinterpret_cast<unw_word_t>(handler+1);
if (*handler) {
_info.handler = reinterpret_cast<unw_word_t>(__libunwind_seh_personality);
} else
_info.handler = 0;
} else {
_info.lsda = 0;
_info.handler = 0;
}
}
#elif defined(_LIBUNWIND_TARGET_ARM)
_info.end_ip = _info.start_ip + unwindEntry->FunctionLength;
_info.lsda = 0; // FIXME
_info.handler = 0; // FIXME
#endif
setLastPC(pc);
return true;
}
#endif
#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
// Masks for traceback table field xtbtable.
enum xTBTableMask : uint8_t {
reservedBit = 0x02, // The traceback table was incorrectly generated if set
// (see comments in function getInfoFromTBTable().
ehInfoBit = 0x08 // Exception handling info is present if set
};
enum frameType : unw_word_t {
frameWithXLEHStateTable = 0,
frameWithEHInfo = 1
};
extern "C" {
typedef _Unwind_Reason_Code __xlcxx_personality_v0_t(int, _Unwind_Action,
uint64_t,
_Unwind_Exception *,
struct _Unwind_Context *);
__attribute__((__weak__)) __xlcxx_personality_v0_t __xlcxx_personality_v0;
}
static __xlcxx_personality_v0_t *xlcPersonalityV0;
static RWMutex xlcPersonalityV0InitLock;
template <typename A, typename R>
bool UnwindCursor<A, R>::getInfoFromTBTable(pint_t pc, R &registers) {
uint32_t *p = reinterpret_cast<uint32_t *>(pc);
// Keep looking forward until a word of 0 is found. The traceback
// table starts at the following word.
while (*p)
++p;
tbtable *TBTable = reinterpret_cast<tbtable *>(p + 1);
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionBuf[512];
const char *functionName = functionBuf;
unw_word_t offset;
if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
functionName = ".anonymous.";
}
_LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
__func__, functionName,
reinterpret_cast<void *>(TBTable));
}
// If the traceback table does not contain necessary info, bypass this frame.
if (!TBTable->tb.has_tboff)
return false;
// Structure tbtable_ext contains important data we are looking for.
p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
// Skip field parminfo if it exists.
if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
++p;
// p now points to tb_offset, the offset from start of function to TB table.
unw_word_t start_ip =
reinterpret_cast<unw_word_t>(TBTable) - *p - sizeof(uint32_t);
unw_word_t end_ip = reinterpret_cast<unw_word_t>(TBTable);
++p;
_LIBUNWIND_TRACE_UNWINDING("start_ip=%p, end_ip=%p\n",
reinterpret_cast<void *>(start_ip),
reinterpret_cast<void *>(end_ip));
// Skip field hand_mask if it exists.
if (TBTable->tb.int_hndl)
++p;
unw_word_t lsda = 0;
unw_word_t handler = 0;
unw_word_t flags = frameType::frameWithXLEHStateTable;
if (TBTable->tb.lang == TB_CPLUSPLUS && TBTable->tb.has_ctl) {
// State table info is available. The ctl_info field indicates the
// number of CTL anchors. There should be only one entry for the C++
// state table.
assert(*p == 1 && "libunwind: there must be only one ctl_info entry");
++p;
// p points to the offset of the state table into the stack.
pint_t stateTableOffset = *p++;
int framePointerReg;
// Skip fields name_len and name if exist.
if (TBTable->tb.name_present) {
const uint16_t name_len = *(reinterpret_cast<uint16_t *>(p));
p = reinterpret_cast<uint32_t *>(reinterpret_cast<char *>(p) + name_len +
sizeof(uint16_t));
}
if (TBTable->tb.uses_alloca)
framePointerReg = *(reinterpret_cast<char *>(p));
else
framePointerReg = 1; // default frame pointer == SP
_LIBUNWIND_TRACE_UNWINDING(
"framePointerReg=%d, framePointer=%p, "
"stateTableOffset=%#lx\n",
framePointerReg,
reinterpret_cast<void *>(_registers.getRegister(framePointerReg)),
stateTableOffset);
lsda = _registers.getRegister(framePointerReg) + stateTableOffset;
// Since the traceback table generated by the legacy XLC++ does not
// provide the location of the personality for the state table,
// function __xlcxx_personality_v0(), which is the personality for the state
// table and is exported from libc++abi, is directly assigned as the
// handler here. When a legacy XLC++ frame is encountered, the symbol
// is resolved dynamically using dlopen() to avoid hard dependency from
// libunwind on libc++abi.
// Resolve the function pointer to the state table personality if it has
// not already.
if (xlcPersonalityV0 == NULL) {
xlcPersonalityV0InitLock.lock();
if (xlcPersonalityV0 == NULL) {
// If libc++abi is statically linked in, symbol __xlcxx_personality_v0
// has been resolved at the link time.
xlcPersonalityV0 = &__xlcxx_personality_v0;
if (xlcPersonalityV0 == NULL) {
// libc++abi is dynamically linked. Resolve __xlcxx_personality_v0
// using dlopen().
const char libcxxabi[] = "libc++abi.a(libc++abi.so.1)";
void *libHandle;
libHandle = dlopen(libcxxabi, RTLD_MEMBER | RTLD_NOW);
if (libHandle == NULL) {
_LIBUNWIND_TRACE_UNWINDING("dlopen() failed with errno=%d\n",
errno);
assert(0 && "dlopen() failed");
}
xlcPersonalityV0 = reinterpret_cast<__xlcxx_personality_v0_t *>(
dlsym(libHandle, "__xlcxx_personality_v0"));
if (xlcPersonalityV0 == NULL) {
_LIBUNWIND_TRACE_UNWINDING("dlsym() failed with errno=%d\n", errno);
assert(0 && "dlsym() failed");
}
dlclose(libHandle);
}
}
xlcPersonalityV0InitLock.unlock();
}
handler = reinterpret_cast<unw_word_t>(xlcPersonalityV0);
_LIBUNWIND_TRACE_UNWINDING("State table: LSDA=%p, Personality=%p\n",
reinterpret_cast<void *>(lsda),
reinterpret_cast<void *>(handler));
} else if (TBTable->tb.longtbtable) {
// This frame has the traceback table extension. Possible cases are
// 1) a C++ frame that has the 'eh_info' structure; 2) a C++ frame that
// is not EH aware; or, 3) a frame of other languages. We need to figure out
// if the traceback table extension contains the 'eh_info' structure.
//
// We also need to deal with the complexity arising from some XL compiler
// versions use the wrong ordering of 'longtbtable' and 'has_vec' bits
// where the 'longtbtable' bit is meant to be the 'has_vec' bit and vice
// versa. For frames of code generated by those compilers, the 'longtbtable'
// bit may be set but there isn't really a traceback table extension.
//
// In </usr/include/sys/debug.h>, there is the following definition of
// 'struct tbtable_ext'. It is not really a structure but a dummy to
// collect the description of optional parts of the traceback table.
//
// struct tbtable_ext {
// ...
// char alloca_reg; /* Register for alloca automatic storage */
// struct vec_ext vec_ext; /* Vector extension (if has_vec is set) */
// unsigned char xtbtable; /* More tbtable fields, if longtbtable is set*/
// };
//
// Depending on how the 'has_vec'/'longtbtable' bit is interpreted, the data
// following 'alloca_reg' can be treated either as 'struct vec_ext' or
// 'unsigned char xtbtable'. 'xtbtable' bits are defined in
// </usr/include/sys/debug.h> as flags. The 7th bit '0x02' is currently
// unused and should not be set. 'struct vec_ext' is defined in
// </usr/include/sys/debug.h> as follows:
//
// struct vec_ext {
// unsigned vr_saved:6; /* Number of non-volatile vector regs saved
// */
// /* first register saved is assumed to be */
// /* 32 - vr_saved */
// unsigned saves_vrsave:1; /* Set if vrsave is saved on the stack */
// unsigned has_varargs:1;
// ...
// };
//
// Here, the 7th bit is used as 'saves_vrsave'. To determine whether it
// is 'struct vec_ext' or 'xtbtable' that follows 'alloca_reg',
// we checks if the 7th bit is set or not because 'xtbtable' should
// never have the 7th bit set. The 7th bit of 'xtbtable' will be reserved
// in the future to make sure the mitigation works. This mitigation
// is not 100% bullet proof because 'struct vec_ext' may not always have
// 'saves_vrsave' bit set.
//
// 'reservedBit' is defined in enum 'xTBTableMask' above as the mask for
// checking the 7th bit.
// p points to field name len.
uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
// Skip fields name_len and name if they exist.
if (TBTable->tb.name_present) {
const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
charPtr = charPtr + name_len + sizeof(uint16_t);
}
// Skip field alloc_reg if it exists.
if (TBTable->tb.uses_alloca)
++charPtr;
// Check traceback table bit has_vec. Skip struct vec_ext if it exists.
if (TBTable->tb.has_vec)
// Note struct vec_ext does exist at this point because whether the
// ordering of longtbtable and has_vec bits is correct or not, both
// are set.
charPtr += sizeof(struct vec_ext);
// charPtr points to field 'xtbtable'. Check if the EH info is available.
// Also check if the reserved bit of the extended traceback table field
// 'xtbtable' is set. If it is, the traceback table was incorrectly
// generated by an XL compiler that uses the wrong ordering of 'longtbtable'
// and 'has_vec' bits and this is in fact 'struct vec_ext'. So skip the
// frame.
if ((*charPtr & xTBTableMask::ehInfoBit) &&
!(*charPtr & xTBTableMask::reservedBit)) {
// Mark this frame has the new EH info.
flags = frameType::frameWithEHInfo;
// eh_info is available.
charPtr++;
// The pointer is 4-byte aligned.
if (reinterpret_cast<uintptr_t>(charPtr) % 4)
charPtr += 4 - reinterpret_cast<uintptr_t>(charPtr) % 4;
uintptr_t *ehInfo =
reinterpret_cast<uintptr_t *>(*(reinterpret_cast<uintptr_t *>(
registers.getRegister(2) +
*(reinterpret_cast<uintptr_t *>(charPtr)))));
// ehInfo points to structure en_info. The first member is version.
// Only version 0 is currently supported.
assert(*(reinterpret_cast<uint32_t *>(ehInfo)) == 0 &&
"libunwind: ehInfo version other than 0 is not supported");
// Increment ehInfo to point to member lsda.
++ehInfo;
lsda = *ehInfo++;
// enInfo now points to member personality.
handler = *ehInfo;
_LIBUNWIND_TRACE_UNWINDING("Range table: LSDA=%#lx, Personality=%#lx\n",
lsda, handler);
}
}
_info.start_ip = start_ip;
_info.end_ip = end_ip;
_info.lsda = lsda;
_info.handler = handler;
_info.gp = 0;
_info.flags = flags;
_info.format = 0;
_info.unwind_info = reinterpret_cast<unw_word_t>(TBTable);
_info.unwind_info_size = 0;
_info.extra = registers.getRegister(2);
return true;
}
// Step back up the stack following the frame back link.
template <typename A, typename R>
int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
R &registers, bool &isSignalFrame) {
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionBuf[512];
const char *functionName = functionBuf;
unw_word_t offset;
if (!getFunctionName(functionBuf, sizeof(functionBuf), &offset)) {
functionName = ".anonymous.";
}
_LIBUNWIND_TRACE_UNWINDING("%s: Look up traceback table of func=%s at %p",
__func__, functionName,
reinterpret_cast<void *>(TBTable));
}
#if defined(__powerpc64__)
// Instruction to reload TOC register "l r2,40(r1)"
const uint32_t loadTOCRegInst = 0xe8410028;
const int32_t unwPPCF0Index = UNW_PPC64_F0;
const int32_t unwPPCV0Index = UNW_PPC64_V0;
#else
// Instruction to reload TOC register "l r2,20(r1)"
const uint32_t loadTOCRegInst = 0x80410014;
const int32_t unwPPCF0Index = UNW_PPC_F0;
const int32_t unwPPCV0Index = UNW_PPC_V0;
#endif
R newRegisters = registers;
// lastStack points to the stack frame of the next routine up.
pint_t lastStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
// Return address is the address after call site instruction.
pint_t returnAddress;
if (isSignalFrame) {
_LIBUNWIND_TRACE_UNWINDING("Possible signal handler frame: lastStack=%p",
reinterpret_cast<void *>(lastStack));
sigcontext *sigContext = reinterpret_cast<sigcontext *>(
reinterpret_cast<char *>(lastStack) + STKMIN);
returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
_LIBUNWIND_TRACE_UNWINDING("From sigContext=%p, returnAddress=%p\n",
reinterpret_cast<void *>(sigContext),
reinterpret_cast<void *>(returnAddress));
if (returnAddress < 0x10000000) {
// Try again using STKMINALIGN
sigContext = reinterpret_cast<sigcontext *>(
reinterpret_cast<char *>(lastStack) + STKMINALIGN);
returnAddress = sigContext->sc_jmpbuf.jmp_context.iar;
if (returnAddress < 0x10000000) {
_LIBUNWIND_TRACE_UNWINDING("Bad returnAddress=%p\n",
reinterpret_cast<void *>(returnAddress));
return UNW_EBADFRAME;
} else {
_LIBUNWIND_TRACE_UNWINDING("Tried again using STKMINALIGN: "
"sigContext=%p, returnAddress=%p. "
"Seems to be a valid address\n",
reinterpret_cast<void *>(sigContext),
reinterpret_cast<void *>(returnAddress));
}
}
// Restore the condition register from sigcontext.
newRegisters.setCR(sigContext->sc_jmpbuf.jmp_context.cr);
// Restore GPRs from sigcontext.
for (int i = 0; i < 32; ++i)
newRegisters.setRegister(i, sigContext->sc_jmpbuf.jmp_context.gpr[i]);
// Restore FPRs from sigcontext.
for (int i = 0; i < 32; ++i)
newRegisters.setFloatRegister(i + unwPPCF0Index,
sigContext->sc_jmpbuf.jmp_context.fpr[i]);
// Restore vector registers if there is an associated extended context
// structure.
if (sigContext->sc_jmpbuf.jmp_context.msr & __EXTCTX) {
ucontext_t *uContext = reinterpret_cast<ucontext_t *>(sigContext);
if (uContext->__extctx->__extctx_magic == __EXTCTX_MAGIC) {
for (int i = 0; i < 32; ++i)
newRegisters.setVectorRegister(
i + unwPPCV0Index, *(reinterpret_cast<v128 *>(
&(uContext->__extctx->__vmx.__vr[i]))));
}
}
} else {
// Step up a normal frame.
returnAddress = reinterpret_cast<pint_t *>(lastStack)[2];
_LIBUNWIND_TRACE_UNWINDING("Extract info from lastStack=%p, "
"returnAddress=%p\n",
reinterpret_cast<void *>(lastStack),
reinterpret_cast<void *>(returnAddress));
_LIBUNWIND_TRACE_UNWINDING("fpr_regs=%d, gpr_regs=%d, saves_cr=%d\n",
TBTable->tb.fpr_saved, TBTable->tb.gpr_saved,
TBTable->tb.saves_cr);
// Restore FP registers.
char *ptrToRegs = reinterpret_cast<char *>(lastStack);
double *FPRegs = reinterpret_cast<double *>(
ptrToRegs - (TBTable->tb.fpr_saved * sizeof(double)));
for (int i = 0; i < TBTable->tb.fpr_saved; ++i)
newRegisters.setFloatRegister(
32 - TBTable->tb.fpr_saved + i + unwPPCF0Index, FPRegs[i]);
// Restore GP registers.
ptrToRegs = reinterpret_cast<char *>(FPRegs);
uintptr_t *GPRegs = reinterpret_cast<uintptr_t *>(
ptrToRegs - (TBTable->tb.gpr_saved * sizeof(uintptr_t)));
for (int i = 0; i < TBTable->tb.gpr_saved; ++i)
newRegisters.setRegister(32 - TBTable->tb.gpr_saved + i, GPRegs[i]);
// Restore Vector registers.
ptrToRegs = reinterpret_cast<char *>(GPRegs);
// Restore vector registers only if this is a Clang frame. Also
// check if traceback table bit has_vec is set. If it is, structure
// vec_ext is available.
if (_info.flags == frameType::frameWithEHInfo && TBTable->tb.has_vec) {
// Get to the vec_ext structure to check if vector registers are saved.
uint32_t *p = reinterpret_cast<uint32_t *>(&TBTable->tb_ext);
// Skip field parminfo if exists.
if (TBTable->tb.fixedparms || TBTable->tb.floatparms)
++p;
// Skip field tb_offset if exists.
if (TBTable->tb.has_tboff)
++p;
// Skip field hand_mask if exists.
if (TBTable->tb.int_hndl)
++p;
// Skip fields ctl_info and ctl_info_disp if exist.
if (TBTable->tb.has_ctl) {
// Skip field ctl_info.
++p;
// Skip field ctl_info_disp.
++p;
}
// Skip fields name_len and name if exist.
// p is supposed to point to field name_len now.
uint8_t *charPtr = reinterpret_cast<uint8_t *>(p);
if (TBTable->tb.name_present) {
const uint16_t name_len = *(reinterpret_cast<uint16_t *>(charPtr));
charPtr = charPtr + name_len + sizeof(uint16_t);
}
// Skip field alloc_reg if it exists.
if (TBTable->tb.uses_alloca)
++charPtr;
struct vec_ext *vec_ext = reinterpret_cast<struct vec_ext *>(charPtr);
_LIBUNWIND_TRACE_UNWINDING("vr_saved=%d\n", vec_ext->vr_saved);
// Restore vector register(s) if saved on the stack.
if (vec_ext->vr_saved) {
// Saved vector registers are 16-byte aligned.
if (reinterpret_cast<uintptr_t>(ptrToRegs) % 16)
ptrToRegs -= reinterpret_cast<uintptr_t>(ptrToRegs) % 16;
v128 *VecRegs = reinterpret_cast<v128 *>(ptrToRegs - vec_ext->vr_saved *
sizeof(v128));
for (int i = 0; i < vec_ext->vr_saved; ++i) {
newRegisters.setVectorRegister(
32 - vec_ext->vr_saved + i + unwPPCV0Index, VecRegs[i]);
}
}
}
if (TBTable->tb.saves_cr) {
// Get the saved condition register. The condition register is only
// a single word.
newRegisters.setCR(
*(reinterpret_cast<uint32_t *>(lastStack + sizeof(uintptr_t))));
}
// Restore the SP.
newRegisters.setSP(lastStack);
// The first instruction after return.
uint32_t firstInstruction = *(reinterpret_cast<uint32_t *>(returnAddress));
// Do we need to set the TOC register?
_LIBUNWIND_TRACE_UNWINDING(
"Current gpr2=%p\n",
reinterpret_cast<void *>(newRegisters.getRegister(2)));
if (firstInstruction == loadTOCRegInst) {
_LIBUNWIND_TRACE_UNWINDING(
"Set gpr2=%p from frame\n",
reinterpret_cast<void *>(reinterpret_cast<pint_t *>(lastStack)[5]));
newRegisters.setRegister(2, reinterpret_cast<pint_t *>(lastStack)[5]);
}
}
_LIBUNWIND_TRACE_UNWINDING("lastStack=%p, returnAddress=%p, pc=%p\n",
reinterpret_cast<void *>(lastStack),
reinterpret_cast<void *>(returnAddress),
reinterpret_cast<void *>(pc));
// The return address is the address after call site instruction, so
// setting IP to that simualates a return.
newRegisters.setIP(reinterpret_cast<uintptr_t>(returnAddress));
// Simulate the step by replacing the register set with the new ones.
registers = newRegisters;
// Check if the next frame is a signal frame.
pint_t nextStack = *(reinterpret_cast<pint_t *>(registers.getSP()));
// Return address is the address after call site instruction.
pint_t nextReturnAddress = reinterpret_cast<pint_t *>(nextStack)[2];
if (nextReturnAddress > 0x01 && nextReturnAddress < 0x10000) {
_LIBUNWIND_TRACE_UNWINDING("The next is a signal handler frame: "
"nextStack=%p, next return address=%p\n",
reinterpret_cast<void *>(nextStack),
reinterpret_cast<void *>(nextReturnAddress));
isSignalFrame = true;
} else {
isSignalFrame = false;
}
return UNW_STEP_SUCCESS;
}
#endif // defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
template <typename A, typename R>
void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
_isSigReturn = false;
#endif
pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
#if defined(_LIBUNWIND_ARM_EHABI)
// Remove the thumb bit so the IP represents the actual instruction address.
// This matches the behaviour of _Unwind_GetIP on arm.
pc &= (pint_t)~0x1;
#endif
// Exit early if at the top of the stack.
if (pc == 0) {
_unwindInfoMissing = true;
return;
}
// If the last line of a function is a "throw" the compiler sometimes
// emits no instructions after the call to __cxa_throw. This means
// the return address is actually the start of the next function.
// To disambiguate this, back up the pc when we know it is a return
// address.
if (isReturnAddress)
#if defined(_AIX)
// PC needs to be a 4-byte aligned address to be able to look for a
// word of 0 that indicates the start of the traceback table at the end
// of a function on AIX.
pc -= 4;
#else
--pc;
#endif
// Ask address space object to find unwind sections for this pc.
UnwindInfoSections sects;
if (_addressSpace.findUnwindSections(pc, sects)) {
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
// If there is a compact unwind encoding table, look there first.
if (sects.compact_unwind_section != 0) {
if (this->getInfoFromCompactEncodingSection(pc, sects)) {
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
// Found info in table, done unless encoding says to use dwarf.
uint32_t dwarfOffset;
if ((sects.dwarf_section != 0) && compactSaysUseDwarf(&dwarfOffset)) {
if (this->getInfoFromDwarfSection(pc, sects, dwarfOffset)) {
// found info in dwarf, done
return;
}
}
#endif
// If unwind table has entry, but entry says there is no unwind info,
// record that we have no unwind info.
if (_info.format == 0)
_unwindInfoMissing = true;
return;
}
}
#endif // defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
#if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
// If there is SEH unwind info, look there next.
if (this->getInfoFromSEH(pc))
return;
#endif
#if defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
// If there is unwind info in the traceback table, look there next.
if (this->getInfoFromTBTable(pc, _registers))
return;
#endif
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
// If there is dwarf unwind info, look there next.
if (sects.dwarf_section != 0) {
if (this->getInfoFromDwarfSection(pc, sects)) {
// found info in dwarf, done
return;
}
}
#endif
#if defined(_LIBUNWIND_ARM_EHABI)
// If there is ARM EHABI unwind info, look there next.
if (sects.arm_section != 0 && this->getInfoFromEHABISection(pc, sects))
return;
#endif
}
#if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
// There is no static unwind info for this pc. Look to see if an FDE was
// dynamically registered for it.
pint_t cachedFDE = DwarfFDECache<A>::findFDE(DwarfFDECache<A>::kSearchAll,
pc);
if (cachedFDE != 0) {
typename CFI_Parser<A>::FDE_Info fdeInfo;
typename CFI_Parser<A>::CIE_Info cieInfo;
if (!CFI_Parser<A>::decodeFDE(_addressSpace, cachedFDE, &fdeInfo, &cieInfo))
if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
return;
}
// Lastly, ask AddressSpace object about platform specific ways to locate
// other FDEs.
pint_t fde;
if (_addressSpace.findOtherFDE(pc, fde)) {
typename CFI_Parser<A>::FDE_Info fdeInfo;
typename CFI_Parser<A>::CIE_Info cieInfo;
if (!CFI_Parser<A>::decodeFDE(_addressSpace, fde, &fdeInfo, &cieInfo)) {
// Double check this FDE is for a function that includes the pc.
if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd))
if (getInfoFromFdeCie(fdeInfo, cieInfo, pc, 0))
return;
}
}
#endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
if (setInfoForSigReturn())
return;
#endif
// no unwind info, flag that we can't reliably unwind
_unwindInfoMissing = true;
}
#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
template <typename A, typename R>
bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
// Look for the sigreturn trampoline. The trampoline's body is two
// specific instructions (see below). Typically the trampoline comes from the
// vDSO[1] (i.e. the __kernel_rt_sigreturn function). A libc might provide its
// own restorer function, though, or user-mode QEMU might write a trampoline
// onto the stack.
//
// This special code path is a fallback that is only used if the trampoline
// lacks proper (e.g. DWARF) unwind info. On AArch64, a new DWARF register
// constant for the PC needs to be defined before DWARF can handle a signal
// trampoline. This code may segfault if the target PC is unreadable, e.g.:
// - The PC points at a function compiled without unwind info, and which is
// part of an execute-only mapping (e.g. using -Wl,--execute-only).
// - The PC is invalid and happens to point to unreadable or unmapped memory.
//
// [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
const pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
// Look for instructions: mov x8, #0x8b; svc #0x0
if (_addressSpace.get32(pc) == 0xd2801168 &&
_addressSpace.get32(pc + 4) == 0xd4000001) {
_info = {};
_isSigReturn = true;
return true;
}
return false;
}
template <typename A, typename R>
int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
// In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
// - 128-byte siginfo struct
// - ucontext struct:
// - 8-byte long (uc_flags)
// - 8-byte pointer (uc_link)
// - 24-byte stack_t
// - 128-byte signal set
// - 8 bytes of padding because sigcontext has 16-byte alignment
// - sigcontext/mcontext_t
// [1] https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
const pint_t kOffsetSpToSigcontext = (128 + 8 + 8 + 24 + 128 + 8); // 304
// Offsets from sigcontext to each register.
const pint_t kOffsetGprs = 8; // offset to "__u64 regs[31]" field
const pint_t kOffsetSp = 256; // offset to "__u64 sp" field
const pint_t kOffsetPc = 264; // offset to "__u64 pc" field
pint_t sigctx = _registers.getSP() + kOffsetSpToSigcontext;
for (int i = 0; i <= 30; ++i) {
uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
static_cast<pint_t>(i * 8));
_registers.setRegister(UNW_AARCH64_X0 + i, value);
}
_registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
_registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
_isSignalFrame = true;
return UNW_STEP_SUCCESS;
}
#endif // defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
template <typename A, typename R>
int UnwindCursor<A, R>::step() {
// Bottom of stack is defined is when unwind info cannot be found.
if (_unwindInfoMissing)
return UNW_STEP_END;
// Use unwinding info to modify register set as if function returned.
int result;
#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
if (_isSigReturn) {
result = this->stepThroughSigReturn();
} else
#endif
{
#if defined(_LIBUNWIND_SUPPORT_COMPACT_UNWIND)
result = this->stepWithCompactEncoding();
#elif defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
result = this->stepWithSEHData();
#elif defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
result = this->stepWithTBTableData();
#elif defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
result = this->stepWithDwarfFDE();
#elif defined(_LIBUNWIND_ARM_EHABI)
result = this->stepWithEHABI();
#else
#error Need _LIBUNWIND_SUPPORT_COMPACT_UNWIND or \
_LIBUNWIND_SUPPORT_SEH_UNWIND or \
_LIBUNWIND_SUPPORT_DWARF_UNWIND or \
_LIBUNWIND_ARM_EHABI
#endif
}
// update info based on new PC
if (result == UNW_STEP_SUCCESS) {
this->setInfoBasedOnIPRegister(true);
if (_unwindInfoMissing)
return UNW_STEP_END;
}
return result;
}
template <typename A, typename R>
void UnwindCursor<A, R>::getInfo(unw_proc_info_t *info) {
if (_unwindInfoMissing)
memset(info, 0, sizeof(*info));
else
*info = _info;
}
template <typename A, typename R>
bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
unw_word_t *offset) {
return _addressSpace.findFunctionName((pint_t)this->getReg(UNW_REG_IP),
buf, bufLen, offset);
}
#if defined(_LIBUNWIND_USE_CET)
extern "C" void *__libunwind_cet_get_registers(unw_cursor_t *cursor) {
AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
return co->get_registers();
}
#endif
} // namespace libunwind
#endif // __UNWINDCURSOR_HPP__
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