- add .eh_frame generation code except for building the actual CIE and FDE instructions

This commit is contained in:
Magnus Norddahl 2018-11-28 13:10:31 +01:00
parent fc7ca39927
commit 232c24e4de

View file

@ -46,6 +46,8 @@ static void *AllocJitMemory(size_t size)
}
}
#ifdef WIN32
#define UWOP_PUSH_NONVOL 0
#define UWOP_ALLOC_LARGE 1
#define UWOP_ALLOC_SMALL 2
@ -56,25 +58,7 @@ static void *AllocJitMemory(size_t size)
#define UWOP_SAVE_XMM128_FAR 9
#define UWOP_PUSH_MACHFRAME 10
void JitRelease()
{
#ifdef _WIN64
for (auto p : JitFrames)
{
RtlDeleteFunctionTable((PRUNTIME_FUNCTION)p);
}
#endif
for (auto p : JitBlocks)
{
asmjit::OSUtils::releaseVirtualMemory(p, 1024 * 1024);
}
JitFrames.Clear();
JitBlocks.Clear();
JitBlockPos = 0;
JitBlockSize = 0;
}
static TArray<uint16_t> CreateUnwindInfo(asmjit::CCFunc *func)
static TArray<uint16_t> CreateUnwindInfoWindows(asmjit::CCFunc *func)
{
using namespace asmjit;
FuncFrameLayout layout;
@ -255,7 +239,7 @@ void *AddJitFunction(asmjit::CodeHolder* code, asmjit::CCFunc *func)
return nullptr;
#ifdef _WIN64
TArray<uint16_t> unwindInfo = CreateUnwindInfo(func);
TArray<uint16_t> unwindInfo = CreateUnwindInfoWindows(func);
size_t unwindInfoSize = unwindInfo.Size() * sizeof(uint16_t);
size_t functionTableSize = sizeof(RUNTIME_FUNCTION);
#else
@ -296,3 +280,334 @@ void *AddJitFunction(asmjit::CodeHolder* code, asmjit::CCFunc *func)
return p;
}
#else
extern "C"
{
void __register_frame(const void*);
void __deregister_frame(const void*);
}
static void WriteLength(TArray<uint8_t> &stream, unsigned int pos, unsigned int v)
{
stream[pos] = v >> 24;
stream[pos + 1] = (v >> 16) & 0xff;
stream[pos + 2] = (v >> 8) & 0xff;
stream[pos + 3] = v & 0xff;
}
static void WriteUInt64(TArray<uint8_t> &stream, uint64_t v)
{
stream.Push(v >> 56);
stream.Push((v >> 48) & 0xff);
stream.Push((v >> 40) & 0xff);
stream.Push((v >> 32) & 0xff);
stream.Push((v >> 24) & 0xff);
stream.Push((v >> 16) & 0xff);
stream.Push((v >> 8) & 0xff);
stream.Push(v & 0xff);
}
static void WriteUInt32(TArray<uint8_t> &stream, uint32_t v)
{
stream.Push(v >> 24);
stream.Push((v >> 16) & 0xff);
stream.Push((v >> 8) & 0xff);
stream.Push(v & 0xff);
}
static void WriteUInt16(TArray<uint8_t> &stream, uint16_t v)
{
stream.Push((v >> 8) & 0xff);
stream.Push(v & 0xff);
}
static void WriteUInt8(TArray<uint8_t> &stream, uint8_t v)
{
stream.Push(v);
}
static void WriteULEB128(TArray<uint8_t> &stream, uint32_t v)
{
}
static void WriteSLEB128(TArray<uint8_t> &stream, int32_t v)
{
}
struct FrameDesc
{
int minInstAlignment = 4;
int dataAlignmentFactor = -4;
uint8_t returnAddressReg = 0;
uint32_t cieLocation = 0;
uint64_t functionStart = 0;
uint64_t functionSize = 0;
};
static void WriteCIE(TArray<uint8_t> &stream, const TArray<uint8_t> &cieInstructions, uint8_t returnAddressReg, int minInstAlignment, int dataAlignmentFactor)
{
unsigned int lengthPos = stream.Size();
WriteUInt32(stream, 0); // Length
WriteUInt32(stream, 0); // CIE ID
WriteUInt8(stream, 1); // CIE Version
WriteUInt8(stream, 'z');
WriteUInt8(stream, 'R');
WriteUInt8(stream, 0);
WriteULEB128(stream, minInstAlignment);
WriteSLEB128(stream, dataAlignmentFactor);
WriteUInt8(stream, returnAddressReg);
WriteULEB128(stream, 0);
for (unsigned int i = 0; i < cieInstructions.Size(); i++)
stream.Push(cieInstructions[i]);
// Padding and update length field
unsigned int length = stream.Size() - lengthPos;
int padding = stream.Size() % 4;
for (int i = 0; i <= padding; i++) WriteUInt8(stream, 0);
WriteLength(stream, lengthPos, length);
}
static void WriteFDE(TArray<uint8_t> &stream, const TArray<uint8_t> &fdeInstructions, uint32_t cieLocation, unsigned int &functionStart)
{
uint32_t offsetToCIE = stream.Size() - cieLocation;
unsigned int lengthPos = stream.Size();
WriteUInt32(stream, 0); // Length
WriteUInt32(stream, offsetToCIE);
functionStart = stream.Size();
WriteUInt64(stream, 0); // func start
WriteUInt64(stream, 0); // func size
for (unsigned int i = 0; i < fdeInstructions.Size(); i++)
stream.Push(fdeInstructions[i]);
// Padding and update length field
unsigned int length = stream.Size() - lengthPos;
int padding = stream.Size() % 4;
for (int i = 0; i <= padding; i++) WriteUInt8(stream, 0);
WriteLength(stream, lengthPos, length);
}
static TArray<uint8_t> CreateUnwindInfoUnix(asmjit::CCFunc *func, unsigned int &functionStart)
{
using namespace asmjit;
FuncFrameLayout layout;
Error error = layout.init(func->getDetail(), func->getFrameInfo());
if (error != kErrorOk)
I_FatalError("FuncFrameLayout.init failed");
// We need a dummy emitter for instruction size calculations
CodeHolder code;
code.init(GetHostCodeInfo());
X86Assembler assembler(&code);
X86Emitter *emitter = assembler.asEmitter();
// Build .eh_frame:
// To do: write CIE and FDE call frame instructions (see appendix D.6 "Call Frame Information Example" in the DWARF 5 spec)
TArray<uint8_t> cieInstructions;
TArray<uint8_t> fdeInstructions;
int minInstAlignment = 4; // To do: is this correct?
int dataAlignmentFactor = -4; // To do: is this correct?
uint8_t returnAddressReg = 0; // To do: get this from asmjit
// Note: this must match exactly what X86Internal::emitProlog does
X86Gp zsp = emitter->zsp(); // ESP|RSP register.
X86Gp zbp = emitter->zsp(); // EBP|RBP register.
zbp.setId(X86Gp::kIdBp);
X86Gp gpReg = emitter->zsp(); // General purpose register (temporary).
X86Gp saReg = emitter->zsp(); // Stack-arguments base register.
uint32_t gpSaved = layout.getSavedRegs(X86Reg::kKindGp);
if (layout.hasPreservedFP())
{
// Emit: 'push zbp'
// 'mov zbp, zsp'.
gpSaved &= ~Utils::mask(X86Gp::kIdBp);
emitter->push(zbp);
// WriteXX(cieInstructions, UWOP_PUSH_NONVOL);
// WriteXX(cieInstructions, X86Gp::kIdBp);
// WriteXX(cieInstructions, (uint32_t)assembler.getOffset());
emitter->mov(zbp, zsp);
}
if (gpSaved)
{
for (uint32_t i = gpSaved, regId = 0; i; i >>= 1, regId++)
{
if (!(i & 0x1)) continue;
// Emit: 'push gp' sequence.
gpReg.setId(regId);
emitter->push(gpReg);
// WriteXX(cieInstructions, UWOP_PUSH_NONVOL);
// WriteXX(cieInstructions, regId);
// WriteXX(cieInstructions, (uint32_t)assembler.getOffset());
}
}
uint32_t stackArgsRegId = layout.getStackArgsRegId();
if (stackArgsRegId != Globals::kInvalidRegId && stackArgsRegId != X86Gp::kIdSp)
{
saReg.setId(stackArgsRegId);
if (!(layout.hasPreservedFP() && stackArgsRegId == X86Gp::kIdBp))
{
// Emit: 'mov saReg, zsp'.
emitter->mov(saReg, zsp);
}
}
if (layout.hasDynamicAlignment())
{
// Emit: 'and zsp, StackAlignment'.
emitter->and_(zsp, -static_cast<int32_t>(layout.getStackAlignment()));
}
if (layout.hasStackAdjustment())
{
// Emit: 'sub zsp, StackAdjustment'.
emitter->sub(zsp, layout.getStackAdjustment());
uint32_t stackadjust = layout.getStackAdjustment();
// WriteXX(cieInstructions, UWOP_ALLOC);
// WriteXX(cieInstructions, stackadjust);
// WriteXX(cieInstructions, (uint32_t)assembler.getOffset());
}
if (layout.hasDynamicAlignment() && layout.hasDsaSlotUsed())
{
// Emit: 'mov [zsp + dsaSlot], saReg'.
X86Mem saMem = x86::ptr(zsp, layout._dsaSlot);
emitter->mov(saMem, saReg);
}
uint32_t xmmSaved = layout.getSavedRegs(X86Reg::kKindVec);
if (xmmSaved)
{
X86Mem vecBase = x86::ptr(zsp, layout.getVecStackOffset());
X86Reg vecReg = x86::xmm(0);
bool avx = layout.isAvxEnabled();
bool aligned = layout.hasAlignedVecSR();
uint32_t vecInst = aligned ? (avx ? X86Inst::kIdVmovaps : X86Inst::kIdMovaps) : (avx ? X86Inst::kIdVmovups : X86Inst::kIdMovups);
uint32_t vecSize = 16;
for (uint32_t i = xmmSaved, regId = 0; i; i >>= 1, regId++)
{
if (!(i & 0x1)) continue;
// Emit 'movaps|movups [zsp + X], xmm0..15'.
vecReg.setId(regId);
emitter->emit(vecInst, vecBase, vecReg);
vecBase.addOffsetLo32(static_cast<int32_t>(vecSize));
// WriteXX(cieInstructions, UWOP_SAVE_XMM128);
// WriteXX(cieInstructions, regId);
// WriteXX(cieInstructions, (uint32_t)assembler.getOffset());
}
}
TArray<uint8_t> stream;
WriteCIE(stream, cieInstructions, returnAddressReg, minInstAlignment, dataAlignmentFactor);
WriteFDE(stream, fdeInstructions, 0, functionStart);
WriteUInt32(stream, 0);
return stream;
}
void *AddJitFunction(asmjit::CodeHolder* code, asmjit::CCFunc *func)
{
using namespace asmjit;
size_t codeSize = code->getCodeSize();
if (codeSize == 0)
return nullptr;
unsigned int fdeFunctionStart = 0;
TArray<uint8_t> unwindInfo;// = CreateUnwindInfoUnix(func, fdeFunctionStart);
size_t unwindInfoSize = unwindInfo.Size();
codeSize = (codeSize + 15) / 16 * 16;
uint8_t *p = (uint8_t *)AllocJitMemory(codeSize + unwindInfoSize);
if (!p)
return nullptr;
size_t relocSize = code->relocate(p);
if (relocSize == 0)
return nullptr;
size_t unwindStart = relocSize;
unwindStart = (unwindStart + 15) / 16 * 16;
JitBlockPos -= codeSize - unwindStart;
uint8_t *baseaddr = JitBlocks.Last();
uint8_t *startaddr = p;
uint8_t *endaddr = p + relocSize;
uint8_t *unwindptr = p + unwindStart;
memcpy(unwindptr, &unwindInfo[0], unwindInfoSize);
if (unwindInfo.Size() > 0)
{
uint64_t *unwindfuncaddr = (uint64_t *)(unwindptr + fdeFunctionStart);
unwindfuncaddr[0] = (ptrdiff_t)startaddr;
unwindfuncaddr[1] = (ptrdiff_t)(endaddr - startaddr);
#ifdef __APPLE__
// On macOS __register_frame takes a single FDE as an argument
uint8_t *entry = unwindptr;
while (true)
{
uint32_t length = *((uint32_t *)entry);
if (length == 0)
break;
uint32_t offset = *((uint32_t *)(entry + 4));
if (offset != 0)
{
__register_frame(entry);
JitFrames.Push(entry);
}
}
#else
// On Linux it takes a pointer to the entire .eh_frame
__register_frame(unwindptr);
JitFrames.Push(unwindptr);
#endif
}
return p;
}
#endif
void JitRelease()
{
#ifdef _WIN64
for (auto p : JitFrames)
{
RtlDeleteFunctionTable((PRUNTIME_FUNCTION)p);
}
#else !defined(WIN32)
for (auto p : JitFrames)
{
__deregister_frame(p);
}
#endif
for (auto p : JitBlocks)
{
asmjit::OSUtils::releaseVirtualMemory(p, 1024 * 1024);
}
JitFrames.Clear();
JitBlocks.Clear();
JitBlockPos = 0;
JitBlockSize = 0;
}