FEX-Emu/FEX
1
0
Fork 0
mirror of https://github.com/FEX-Emu/FEX.git synced 2025-02-22 07:42:03 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

ARM64EC: Rethrow exceptions from within the JIT

Browse Source 
As the exception dispatcher is initially invoked on the emulator stack,
control needs to be transferred to the dispatcher on the guest stack
after recovering the x86 RSP to allow for invoking x86 exception
handlers.
This commit is contained in:
Billy Laws 2024-07-12 00:23:27 +01:00
parent f964a5187e
commit 3c19e634b3
1 changed files with 109 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

113
Source/Windows/ARM64EC/Module.cpp
View File

@ -111,8 +111,8 @@ bool IsDispatcherAddress(uint64_t Address) {
return Address >= Config.DispatcherBegin && Address < Config.DispatcherEnd;
}
// GetProcAddress on ARM64EC returns a pointer to an x64 fast forward sequence to allow for redirecting to the JIT if functions are hotpatched.
// This looks up the procedure address of the native code even if the fast forward sequence has been patched.
// GetProcAddress on ARM64EC returns a pointer to an x64 fast forward sequence to allow for redirecting to the JIT if functions are
// hotpatched. This looks up the procedure address of the native code even if the fast forward sequence has been patched.
uintptr_t GetRedirectedProcAddress(HMODULE Module, const char* ProcName) {
const uintptr_t Proc = reinterpret_cast<uintptr_t>(GetProcAddress(Module, ProcName));
if (!Proc) {
@ -138,6 +138,7 @@ uintptr_t GetRedirectedProcAddress(HMODULE Module, const char* ProcName) {
namespace Exception {
static std::optional<FEX::Windows::TSOHandlerConfig> HandlerConfig;
static uintptr_t KiUserExceptionDispatcher;
static bool HandleUnalignedAccess(ARM64_NT_CONTEXT& Context) {
if (!CTX->IsAddressInCodeBuffer(GetCPUArea().ThreadState(), Context.Pc)) {
@ -207,6 +208,101 @@ static void LoadStateFromECContext(FEXCore::Core::InternalThreadState* Thread, C
State.flags[FEXCore::X86State::X87FLAG_TOP_LOC] = (Context.FltSave.StatusWord >> 11) & 0b111;
State.AbridgedFTW = Context.FltSave.TagWord;
}
static void ReconstructThreadState(ARM64_NT_CONTEXT& Context) {
const auto& Config = SignalDelegator->GetConfig();
auto* Thread = GetCPUArea().ThreadState();
auto& State = Thread->CurrentFrame->State;
State.rip = CTX->RestoreRIPFromHostPC(Thread, Context.Pc);
// Spill all SRA GPRs
for (size_t i = 0; i < Config.SRAGPRCount; i++) {
State.gregs[i] = Context.X[Config.SRAGPRMapping[i]];
}
// Spill all SRA FPRs
for (size_t i = 0; i < Config.SRAFPRCount; i++) {
memcpy(State.xmm.sse.data[i], &Context.V[Config.SRAFPRMapping[i]], sizeof(__uint128_t));
}
}
// Reconstructs an x64 context from the input context within the JIT, packed into a regular ARM64 context following the ARM64EC register mapping
static ARM64_NT_CONTEXT ReconstructPackedECContext(ARM64_NT_CONTEXT& Context) {
ReconstructThreadState(Context);
ARM64_NT_CONTEXT ECContext {};
ECContext.ContextFlags = CONTEXT_ARM64_CONTROL | CONTEXT_ARM64_INTEGER | CONTEXT_ARM64_FLOATING_POINT;
auto* Thread = GetCPUArea().ThreadState();
auto& State = Thread->CurrentFrame->State;
ECContext.X8 = State.gregs[FEXCore::X86State::REG_RAX];
ECContext.X0 = State.gregs[FEXCore::X86State::REG_RCX];
ECContext.X1 = State.gregs[FEXCore::X86State::REG_RDX];
ECContext.X27 = State.gregs[FEXCore::X86State::REG_RBX];
ECContext.Sp = State.gregs[FEXCore::X86State::REG_RSP];
ECContext.Fp = State.gregs[FEXCore::X86State::REG_RBP];
ECContext.X25 = State.gregs[FEXCore::X86State::REG_RSI];
ECContext.X26 = State.gregs[FEXCore::X86State::REG_RDI];
ECContext.X2 = State.gregs[FEXCore::X86State::REG_R8];
ECContext.X3 = State.gregs[FEXCore::X86State::REG_R9];
ECContext.X4 = State.gregs[FEXCore::X86State::REG_R10];
ECContext.X5 = State.gregs[FEXCore::X86State::REG_R11];
ECContext.X19 = State.gregs[FEXCore::X86State::REG_R12];
ECContext.X20 = State.gregs[FEXCore::X86State::REG_R13];
ECContext.X21 = State.gregs[FEXCore::X86State::REG_R14];
ECContext.X22 = State.gregs[FEXCore::X86State::REG_R15];
ECContext.Pc = State.rip;
CTX->ReconstructXMMRegisters(Thread, reinterpret_cast<__uint128_t*>(&ECContext.V[0]), nullptr);
ECContext.Lr = State.mm[0][0];
ECContext.X6 = State.mm[1][0];
ECContext.X7 = State.mm[2][0];
ECContext.X9 = State.mm[3][0];
ECContext.X16 = (State.mm[3][1] & 0xffff) << 48 | (State.mm[2][1] & 0xffff) << 32 | (State.mm[1][1] & 0xffff) << 16 | (State.mm[0][1] & 0xffff);
ECContext.X10 = State.mm[4][0];
ECContext.X11 = State.mm[5][0];
ECContext.X12 = State.mm[6][0];
ECContext.X15 = State.mm[7][0];
ECContext.X17 = (State.mm[7][1] & 0xffff) << 48 | (State.mm[6][1] & 0xffff) << 32 | (State.mm[5][1] & 0xffff) << 16 | (State.mm[4][1] & 0xffff);
// Zero all disallowed registers
ECContext.X13 = 0;
ECContext.X14 = 0;
ECContext.X18 = 0;
ECContext.X23 = 0;
ECContext.X24 = 0;
ECContext.X28 = 0;
// NZCV will be converted into EFlags by ntdll, the rest are lost during exception handling.
// See HandleGuestException
ECContext.Cpsr = Context.Cpsr;
ECContext.Fpcr = Context.Fpcr;
ECContext.Fpsr = Context.Fpsr;
return ECContext;
}
static void RethrowGuestException(const EXCEPTION_RECORD& Rec, ARM64_NT_CONTEXT& Context) {
const auto& Config = SignalDelegator->GetConfig();
uint64_t GuestSp = Context.X[Config.SRAGPRMapping[static_cast<size_t>(FEXCore::X86State::REG_RSP)]];
struct DispatchArgs {
ARM64_NT_CONTEXT Context;
EXCEPTION_RECORD Rec;
uint64_t Align;
uint64_t Redzone[2];
}* Args = reinterpret_cast<DispatchArgs*>(FEXCore::AlignDown(GuestSp, 64)) - 1;
LogMan::Msg::DFmt("Reconstructing context");
Args->Context = ReconstructPackedECContext(Context);
LogMan::Msg::DFmt("pc: {:X} rip: {:X}", Context.Pc, Args->Context.Pc);
Args->Rec = *Ptrs->ExceptionRecord;
Context.Sp = reinterpret_cast<uint64_t>(Args);
Context.Pc = KiUserExceptionDispatcher;
}
} // namespace Exception
namespace Logging {
@ -283,6 +379,8 @@ void ProcessInit() {
X64ReturnInstr = ::VirtualAlloc(nullptr, FEXCore::Utils::FEX_PAGE_SIZE, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
*reinterpret_cast<uint8_t*>(X64ReturnInstr) = 0xc3;
Exception::KiUserExceptionDispatcher = GetRedirectedProcAddress(GetModuleHandle("ntdll.dll"), "KiUserExceptionDispatcher");
}
void ProcessTerm() {}
@ -331,9 +429,16 @@ NTSTATUS ResetToConsistentState(EXCEPTION_POINTERS* Ptrs, ARM64_NT_CONTEXT* Cont
return STATUS_SUCCESS;
}
LogMan::Msg::EFmt("Exception rethrow is unimplemented");
return STATUS_SUCCESS;
if (IsEmulatorStackAddress(reinterpret_cast<uint64_t>(__builtin_frame_address(0)))) {
Exception::RethrowGuestException(*Exception, *Context);
LogMan::Msg::DFmt("Rethrowing onto guest stack: {:X}", Context->Sp);
*Continue = true;
return STATUS_SUCCESS;
} else {
LogMan::Msg::EFmt("Unexpected exception in JIT code on guest stack");
return STATUS_SUCCESS;
}
}
void NotifyMemoryAlloc(void* Address, SIZE_T Size, ULONG Type, ULONG Prot) {