/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- * vim: set ts=8 sts=2 et sw=2 tw=80: * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "jit/Bailouts.h" #include "jit/BaselineFrame.h" #include "jit/CalleeToken.h" #include "jit/JitFrames.h" #include "jit/JitRuntime.h" #ifdef JS_ION_PERF # include "jit/PerfSpewer.h" #endif #include "jit/VMFunctions.h" #include "jit/x64/SharedICHelpers-x64.h" #ifdef MOZ_VTUNE # include "vtune/VTuneWrapper.h" #endif #include "vm/JitActivation.h" // js::jit::JitActivation #include "vm/JSContext.h" #include "jit/MacroAssembler-inl.h" using namespace js; using namespace js::jit; using mozilla::IsPowerOfTwo; // All registers to save and restore. This includes the stack pointer, since we // use the ability to reference register values on the stack by index. static const LiveRegisterSet AllRegs = LiveRegisterSet(GeneralRegisterSet(Registers::AllMask), FloatRegisterSet(FloatRegisters::AllMask)); // Generates a trampoline for calling Jit compiled code from a C++ function. // The trampoline use the EnterJitCode signature, with the standard x64 fastcall // calling convention. void JitRuntime::generateEnterJIT(JSContext* cx, MacroAssembler& masm) { enterJITOffset_ = startTrampolineCode(masm); masm.assertStackAlignment(ABIStackAlignment, -int32_t(sizeof(uintptr_t)) /* return address */); const Register reg_code = IntArgReg0; const Register reg_argc = IntArgReg1; const Register reg_argv = IntArgReg2; static_assert(OsrFrameReg == IntArgReg3); #if defined(_WIN64) const Address token = Address(rbp, 16 + ShadowStackSpace); const Operand scopeChain = Operand(rbp, 24 + ShadowStackSpace); const Operand numStackValuesAddr = Operand(rbp, 32 + ShadowStackSpace); const Operand result = Operand(rbp, 40 + ShadowStackSpace); #else const Register token = IntArgReg4; const Register scopeChain = IntArgReg5; const Operand numStackValuesAddr = Operand(rbp, 16 + ShadowStackSpace); const Operand result = Operand(rbp, 24 + ShadowStackSpace); #endif // Save old stack frame pointer, set new stack frame pointer. masm.push(rbp); masm.mov(rsp, rbp); // Save non-volatile registers. These must be saved by the trampoline, rather // than by the JIT'd code, because they are scanned by the conservative // scanner. masm.push(rbx); masm.push(r12); masm.push(r13); masm.push(r14); masm.push(r15); #if defined(_WIN64) masm.push(rdi); masm.push(rsi); // 16-byte aligment for vmovdqa masm.subq(Imm32(16 * 10 + 8), rsp); masm.vmovdqa(xmm6, Operand(rsp, 16 * 0)); masm.vmovdqa(xmm7, Operand(rsp, 16 * 1)); masm.vmovdqa(xmm8, Operand(rsp, 16 * 2)); masm.vmovdqa(xmm9, Operand(rsp, 16 * 3)); masm.vmovdqa(xmm10, Operand(rsp, 16 * 4)); masm.vmovdqa(xmm11, Operand(rsp, 16 * 5)); masm.vmovdqa(xmm12, Operand(rsp, 16 * 6)); masm.vmovdqa(xmm13, Operand(rsp, 16 * 7)); masm.vmovdqa(xmm14, Operand(rsp, 16 * 8)); masm.vmovdqa(xmm15, Operand(rsp, 16 * 9)); #endif // Save arguments passed in registers needed after function call. masm.push(result); // Remember stack depth without padding and arguments. masm.mov(rsp, r14); // Remember number of bytes occupied by argument vector masm.mov(reg_argc, r13); // if we are constructing, that also needs to include newTarget { Label noNewTarget; masm.branchTest32(Assembler::Zero, token, Imm32(CalleeToken_FunctionConstructing), &noNewTarget); masm.addq(Imm32(1), r13); masm.bind(&noNewTarget); } masm.shll(Imm32(3), r13); // r13 = argc * sizeof(Value) static_assert(sizeof(Value) == 1 << 3, "Constant is baked in assembly code"); // Guarantee stack alignment of Jit frames. // // This code compensates for the offset created by the copy of the vector of // arguments, such that the jit frame will be aligned once the return // address is pushed on the stack. // // In the computation of the offset, we omit the size of the JitFrameLayout // which is pushed on the stack, as the JitFrameLayout size is a multiple of // the JitStackAlignment. masm.mov(rsp, r12); masm.subq(r13, r12); static_assert( sizeof(JitFrameLayout) % JitStackAlignment == 0, "No need to consider the JitFrameLayout for aligning the stack"); masm.andl(Imm32(JitStackAlignment - 1), r12); masm.subq(r12, rsp); /*************************************************************** Loop over argv vector, push arguments onto stack in reverse order ***************************************************************/ // r13 still stores the number of bytes in the argument vector. masm.addq(reg_argv, r13); // r13 points above last argument or newTarget // while r13 > rdx, push arguments. { Label header, footer; masm.bind(&header); masm.cmpPtr(r13, reg_argv); masm.j(AssemblerX86Shared::BelowOrEqual, &footer); masm.subq(Imm32(8), r13); masm.push(Operand(r13, 0)); masm.jmp(&header); masm.bind(&footer); } // Push the number of actual arguments. |result| is used to store the // actual number of arguments without adding an extra argument to the enter // JIT. masm.movq(result, reg_argc); masm.unboxInt32(Operand(reg_argc, 0), reg_argc); masm.push(reg_argc); // Push the callee token. masm.push(token); /***************************************************************** Push the number of bytes we've pushed so far on the stack and call *****************************************************************/ masm.subq(rsp, r14); // Create a frame descriptor. masm.makeFrameDescriptor(r14, FrameType::CppToJSJit, JitFrameLayout::Size()); masm.push(r14); CodeLabel returnLabel; CodeLabel oomReturnLabel; { // Handle Interpreter -> Baseline OSR. AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All()); regs.takeUnchecked(OsrFrameReg); regs.take(rbp); regs.take(reg_code); // Ensure that |scratch| does not end up being JSReturnOperand. // Do takeUnchecked because on Win64/x64, reg_code (IntArgReg0) and // JSReturnOperand are the same (rcx). See bug 849398. regs.takeUnchecked(JSReturnOperand); Register scratch = regs.takeAny(); Label notOsr; masm.branchTestPtr(Assembler::Zero, OsrFrameReg, OsrFrameReg, ¬Osr); Register numStackValues = regs.takeAny(); masm.movq(numStackValuesAddr, numStackValues); // Push return address masm.mov(&returnLabel, scratch); masm.push(scratch); // Push previous frame pointer. masm.push(rbp); // Reserve frame. Register framePtr = rbp; masm.subPtr(Imm32(BaselineFrame::Size()), rsp); masm.touchFrameValues(numStackValues, scratch, framePtr); masm.mov(rsp, framePtr); // Reserve space for locals and stack values. Register valuesSize = regs.takeAny(); masm.mov(numStackValues, valuesSize); masm.shll(Imm32(3), valuesSize); masm.subPtr(valuesSize, rsp); // Enter exit frame. masm.addPtr( Imm32(BaselineFrame::Size() + BaselineFrame::FramePointerOffset), valuesSize); masm.makeFrameDescriptor(valuesSize, FrameType::BaselineJS, ExitFrameLayout::Size()); masm.push(valuesSize); masm.push(Imm32(0)); // Fake return address. // No GC things to mark, push a bare token. masm.loadJSContext(scratch); masm.enterFakeExitFrame(scratch, scratch, ExitFrameType::Bare); regs.add(valuesSize); masm.push(framePtr); masm.push(reg_code); using Fn = bool (*)(BaselineFrame * frame, InterpreterFrame * interpFrame, uint32_t numStackValues); masm.setupUnalignedABICall(scratch); masm.passABIArg(framePtr); // BaselineFrame masm.passABIArg(OsrFrameReg); // InterpreterFrame masm.passABIArg(numStackValues); masm.callWithABI( MoveOp::GENERAL, CheckUnsafeCallWithABI::DontCheckHasExitFrame); masm.pop(reg_code); masm.pop(framePtr); MOZ_ASSERT(reg_code != ReturnReg); Label error; masm.addPtr(Imm32(ExitFrameLayout::SizeWithFooter()), rsp); masm.addPtr(Imm32(BaselineFrame::Size()), framePtr); masm.branchIfFalseBool(ReturnReg, &error); // If OSR-ing, then emit instrumentation for setting lastProfilerFrame // if profiler instrumentation is enabled. { Label skipProfilingInstrumentation; Register realFramePtr = numStackValues; AbsoluteAddress addressOfEnabled( cx->runtime()->geckoProfiler().addressOfEnabled()); masm.branch32(Assembler::Equal, addressOfEnabled, Imm32(0), &skipProfilingInstrumentation); masm.lea(Operand(framePtr, sizeof(void*)), realFramePtr); masm.profilerEnterFrame(realFramePtr, scratch); masm.bind(&skipProfilingInstrumentation); } masm.jump(reg_code); // OOM: load error value, discard return address and previous frame // pointer and return. masm.bind(&error); masm.mov(framePtr, rsp); masm.addPtr(Imm32(2 * sizeof(uintptr_t)), rsp); masm.moveValue(MagicValue(JS_ION_ERROR), JSReturnOperand); masm.mov(&oomReturnLabel, scratch); masm.jump(scratch); masm.bind(¬Osr); masm.movq(scopeChain, R1.scratchReg()); } // The call will push the return address on the stack, thus we check that // the stack would be aligned once the call is complete. masm.assertStackAlignment(JitStackAlignment, sizeof(uintptr_t)); // Call function. masm.callJitNoProfiler(reg_code); { // Interpreter -> Baseline OSR will return here. masm.bind(&returnLabel); masm.addCodeLabel(returnLabel); masm.bind(&oomReturnLabel); masm.addCodeLabel(oomReturnLabel); } // Pop arguments and padding from stack. masm.pop(r14); // Pop and decode descriptor. masm.shrq(Imm32(FRAMESIZE_SHIFT), r14); masm.addq(r14, rsp); // Remove arguments. /***************************************************************** Place return value where it belongs, pop all saved registers *****************************************************************/ masm.pop(r12); // vp masm.storeValue(JSReturnOperand, Operand(r12, 0)); // Restore non-volatile registers. #if defined(_WIN64) masm.vmovdqa(Operand(rsp, 16 * 0), xmm6); masm.vmovdqa(Operand(rsp, 16 * 1), xmm7); masm.vmovdqa(Operand(rsp, 16 * 2), xmm8); masm.vmovdqa(Operand(rsp, 16 * 3), xmm9); masm.vmovdqa(Operand(rsp, 16 * 4), xmm10); masm.vmovdqa(Operand(rsp, 16 * 5), xmm11); masm.vmovdqa(Operand(rsp, 16 * 6), xmm12); masm.vmovdqa(Operand(rsp, 16 * 7), xmm13); masm.vmovdqa(Operand(rsp, 16 * 8), xmm14); masm.vmovdqa(Operand(rsp, 16 * 9), xmm15); masm.addq(Imm32(16 * 10 + 8), rsp); masm.pop(rsi); masm.pop(rdi); #endif masm.pop(r15); masm.pop(r14); masm.pop(r13); masm.pop(r12); masm.pop(rbx); // Restore frame pointer and return. masm.pop(rbp); masm.ret(); } // Push AllRegs in a way that is compatible with RegisterDump, regardless of // what PushRegsInMask might do to reduce the set size. static void DumpAllRegs(MacroAssembler& masm) { #ifdef ENABLE_WASM_SIMD masm.PushRegsInMask(AllRegs); #else // When SIMD isn't supported, PushRegsInMask reduces the set of float // registers to be double-sized, while the RegisterDump expects each of // the float registers to have the maximal possible size // (Simd128DataSize). To work around this, we just spill the double // registers by hand here, using the register dump offset directly. for (GeneralRegisterBackwardIterator iter(AllRegs.gprs()); iter.more(); ++iter) { masm.Push(*iter); } masm.reserveStack(sizeof(RegisterDump::FPUArray)); for (FloatRegisterBackwardIterator iter(AllRegs.fpus()); iter.more(); ++iter) { FloatRegister reg = *iter; Address spillAddress(StackPointer, reg.getRegisterDumpOffsetInBytes()); masm.storeDouble(reg, spillAddress); } #endif } void JitRuntime::generateInvalidator(MacroAssembler& masm, Label* bailoutTail) { // See explanatory comment in x86's JitRuntime::generateInvalidator. invalidatorOffset_ = startTrampolineCode(masm); // Push registers such that we can access them from [base + code]. DumpAllRegs(masm); masm.movq(rsp, rax); // Argument to jit::InvalidationBailout. // Make space for InvalidationBailout's frameSize outparam. masm.reserveStack(sizeof(size_t)); masm.movq(rsp, rbx); // Make space for InvalidationBailout's bailoutInfo outparam. masm.reserveStack(sizeof(void*)); masm.movq(rsp, r9); using Fn = bool (*)(InvalidationBailoutStack * sp, size_t * frameSizeOut, BaselineBailoutInfo * *info); masm.setupUnalignedABICall(rdx); masm.passABIArg(rax); masm.passABIArg(rbx); masm.passABIArg(r9); masm.callWithABI( MoveOp::GENERAL, CheckUnsafeCallWithABI::DontCheckOther); masm.pop(r9); // Get the bailoutInfo outparam. masm.pop(rbx); // Get the frameSize outparam. // Pop the machine state and the dead frame. masm.lea(Operand(rsp, rbx, TimesOne, sizeof(InvalidationBailoutStack)), rsp); // Jump to shared bailout tail. The BailoutInfo pointer has to be in r9. masm.jmp(bailoutTail); } void JitRuntime::generateArgumentsRectifier(MacroAssembler& masm, ArgumentsRectifierKind kind) { // Do not erase the frame pointer in this function. switch (kind) { case ArgumentsRectifierKind::Normal: argumentsRectifierOffset_ = startTrampolineCode(masm); break; case ArgumentsRectifierKind::TrialInlining: trialInliningArgumentsRectifierOffset_ = startTrampolineCode(masm); break; } // Caller: // [arg2] [arg1] [this] [[argc] [callee] [descr] [raddr]] <- rsp // Add |this|, in the counter of known arguments. masm.loadPtr(Address(rsp, RectifierFrameLayout::offsetOfNumActualArgs()), r8); masm.addl(Imm32(1), r8); // Load |nformals| into %rcx. masm.loadPtr(Address(rsp, RectifierFrameLayout::offsetOfCalleeToken()), rax); masm.mov(rax, rcx); masm.andq(Imm32(uint32_t(CalleeTokenMask)), rcx); masm.movzwl(Operand(rcx, JSFunction::offsetOfNargs()), rcx); // Stash another copy in r11, since we are going to do destructive operations // on rcx masm.mov(rcx, r11); static_assert( CalleeToken_FunctionConstructing == 1, "Ensure that we can use the constructing bit to count the value"); masm.mov(rax, rdx); masm.andq(Imm32(uint32_t(CalleeToken_FunctionConstructing)), rdx); // Including |this|, and |new.target|, there are (|nformals| + 1 + // isConstructing) arguments to push to the stack. Then we push a // JitFrameLayout. We compute the padding expressed in the number of extra // |undefined| values to push on the stack. static_assert( sizeof(JitFrameLayout) % JitStackAlignment == 0, "No need to consider the JitFrameLayout for aligning the stack"); static_assert( JitStackAlignment % sizeof(Value) == 0, "Ensure that we can pad the stack by pushing extra UndefinedValue"); static_assert(IsPowerOfTwo(JitStackValueAlignment), "must have power of two for masm.andl to do its job"); masm.addl( Imm32(JitStackValueAlignment - 1 /* for padding */ + 1 /* for |this| */), rcx); masm.addl(rdx, rcx); masm.andl(Imm32(~(JitStackValueAlignment - 1)), rcx); // Load the number of |undefined|s to push into %rcx. masm.subq(r8, rcx); // Caller: // [arg2] [arg1] [this] [ [argc] [callee] [descr] [raddr] ] <- rsp <- r9 // '------ #r8 -------' // // Rectifier frame: // [undef] [undef] [undef] [arg2] [arg1] [this] [ [argc] [callee] // [descr] [raddr] ] // '------- #rcx --------' '------ #r8 -------' // Copy the number of actual arguments into rdx. Use lea to subtract 1 for // |this|. masm.lea(Operand(r8, -1), rdx); masm.moveValue(UndefinedValue(), ValueOperand(r10)); masm.movq(rsp, r9); // Save %rsp. // Push undefined. (including the padding) { Label undefLoopTop; masm.bind(&undefLoopTop); masm.push(r10); masm.subl(Imm32(1), rcx); masm.j(Assembler::NonZero, &undefLoopTop); } // Get the topmost argument. static_assert(sizeof(Value) == 8, "TimesEight is used to skip arguments"); // | - sizeof(Value)| is used to put rcx such that we can read the last // argument, and not the value which is after. BaseIndex b(r9, r8, TimesEight, sizeof(RectifierFrameLayout) - sizeof(Value)); masm.lea(Operand(b), rcx); // Copy & Push arguments, |nargs| + 1 times (to include |this|). { Label copyLoopTop; masm.bind(©LoopTop); masm.push(Operand(rcx, 0x0)); masm.subq(Imm32(sizeof(Value)), rcx); masm.subl(Imm32(1), r8); masm.j(Assembler::NonZero, ©LoopTop); } // if constructing, copy newTarget { Label notConstructing; masm.branchTest32(Assembler::Zero, rax, Imm32(CalleeToken_FunctionConstructing), ¬Constructing); // thisFrame[numFormals] = prevFrame[argc] ValueOperand newTarget(r10); // +1 for |this|. We want vp[argc], so don't subtract 1 BaseIndex newTargetSrc(r9, rdx, TimesEight, sizeof(RectifierFrameLayout) + sizeof(Value)); masm.loadValue(newTargetSrc, newTarget); // Again, 1 for |this| BaseIndex newTargetDest(rsp, r11, TimesEight, sizeof(Value)); masm.storeValue(newTarget, newTargetDest); masm.bind(¬Constructing); } // Caller: // [arg2] [arg1] [this] [ [argc] [callee] [descr] [raddr] ] <- r9 // // // Rectifier frame: // [undef] [undef] [undef] [arg2] [arg1] [this] <- rsp [ [argc] [callee] // [descr] [raddr] ] // // Construct descriptor. masm.subq(rsp, r9); masm.makeFrameDescriptor(r9, FrameType::Rectifier, JitFrameLayout::Size()); // Construct JitFrameLayout. masm.push(rdx); // numActualArgs masm.push(rax); // callee token masm.push(r9); // descriptor // Call the target function. masm.andq(Imm32(uint32_t(CalleeTokenMask)), rax); switch (kind) { case ArgumentsRectifierKind::Normal: masm.loadJitCodeRaw(rax, rax); argumentsRectifierReturnOffset_ = masm.callJitNoProfiler(rax); break; case ArgumentsRectifierKind::TrialInlining: Label noBaselineScript, done; masm.loadBaselineJitCodeRaw(rax, rbx, &noBaselineScript); masm.callJitNoProfiler(rbx); masm.jump(&done); // See BaselineCacheIRCompiler::emitCallInlinedFunction. masm.bind(&noBaselineScript); masm.loadJitCodeRaw(rax, rax); masm.callJitNoProfiler(rax); masm.bind(&done); break; } // Remove the rectifier frame. masm.pop(r9); // r9 <- descriptor with FrameType. masm.shrq(Imm32(FRAMESIZE_SHIFT), r9); masm.pop(r11); // Discard calleeToken. masm.pop(r11); // Discard numActualArgs. masm.addq(r9, rsp); // Discard pushed arguments. masm.ret(); } static void PushBailoutFrame(MacroAssembler& masm, Register spArg) { // Push registers such that we can access them from [base + code]. DumpAllRegs(masm); // Get the stack pointer into a register, pre-alignment. masm.movq(rsp, spArg); } static void GenerateBailoutThunk(MacroAssembler& masm, uint32_t frameClass, Label* bailoutTail) { PushBailoutFrame(masm, r8); // Make space for Bailout's bailoutInfo outparam. masm.reserveStack(sizeof(void*)); masm.movq(rsp, r9); // Call the bailout function. using Fn = bool (*)(BailoutStack * sp, BaselineBailoutInfo * *info); masm.setupUnalignedABICall(rax); masm.passABIArg(r8); masm.passABIArg(r9); masm.callWithABI(MoveOp::GENERAL, CheckUnsafeCallWithABI::DontCheckOther); masm.pop(r9); // Get the bailoutInfo outparam. // Stack is: // [frame] // snapshotOffset // frameSize // [bailoutFrame] // // Remove both the bailout frame and the topmost Ion frame's stack. static const uint32_t BailoutDataSize = sizeof(RegisterDump); masm.addq(Imm32(BailoutDataSize), rsp); masm.pop(rcx); masm.lea(Operand(rsp, rcx, TimesOne, sizeof(void*)), rsp); // Jump to shared bailout tail. The BailoutInfo pointer has to be in r9. masm.jmp(bailoutTail); } JitRuntime::BailoutTable JitRuntime::generateBailoutTable(MacroAssembler& masm, Label* bailoutTail, uint32_t frameClass) { MOZ_CRASH("x64 does not use bailout tables"); } void JitRuntime::generateBailoutHandler(MacroAssembler& masm, Label* bailoutTail) { bailoutHandlerOffset_ = startTrampolineCode(masm); GenerateBailoutThunk(masm, NO_FRAME_SIZE_CLASS_ID, bailoutTail); } bool JitRuntime::generateVMWrapper(JSContext* cx, MacroAssembler& masm, const VMFunctionData& f, DynFn nativeFun, uint32_t* wrapperOffset) { *wrapperOffset = startTrampolineCode(masm); // Avoid conflicts with argument registers while discarding the result after // the function call. AllocatableGeneralRegisterSet regs(Register::Codes::WrapperMask); static_assert( (Register::Codes::VolatileMask & ~Register::Codes::WrapperMask) == 0, "Wrapper register set must be a superset of Volatile register set"); // The context is the first argument. Register cxreg = IntArgReg0; regs.take(cxreg); // Stack is: // ... frame ... // +12 [args] // +8 descriptor // +0 returnAddress // // We're aligned to an exit frame, so link it up. masm.loadJSContext(cxreg); masm.enterExitFrame(cxreg, regs.getAny(), &f); // Save the current stack pointer as the base for copying arguments. Register argsBase = InvalidReg; if (f.explicitArgs) { argsBase = r10; regs.take(argsBase); masm.lea(Operand(rsp, ExitFrameLayout::SizeWithFooter()), argsBase); } // Reserve space for the outparameter. Register outReg = InvalidReg; switch (f.outParam) { case Type_Value: outReg = regs.takeAny(); masm.reserveStack(sizeof(Value)); masm.movq(esp, outReg); break; case Type_Handle: outReg = regs.takeAny(); masm.PushEmptyRooted(f.outParamRootType); masm.movq(esp, outReg); break; case Type_Int32: case Type_Bool: case Type_Pointer: outReg = regs.takeAny(); masm.reserveStack(sizeof(uintptr_t)); masm.movq(esp, outReg); break; case Type_Double: outReg = regs.takeAny(); masm.reserveStack(sizeof(double)); masm.movq(esp, outReg); break; default: MOZ_ASSERT(f.outParam == Type_Void); break; } if (!generateTLEnterVM(masm, f)) { return false; } masm.setupUnalignedABICall(regs.getAny()); masm.passABIArg(cxreg); size_t argDisp = 0; // Copy arguments. for (uint32_t explicitArg = 0; explicitArg < f.explicitArgs; explicitArg++) { switch (f.argProperties(explicitArg)) { case VMFunctionData::WordByValue: if (f.argPassedInFloatReg(explicitArg)) { masm.passABIArg(MoveOperand(argsBase, argDisp), MoveOp::DOUBLE); } else { masm.passABIArg(MoveOperand(argsBase, argDisp), MoveOp::GENERAL); } argDisp += sizeof(void*); break; case VMFunctionData::WordByRef: masm.passABIArg( MoveOperand(argsBase, argDisp, MoveOperand::EFFECTIVE_ADDRESS), MoveOp::GENERAL); argDisp += sizeof(void*); break; case VMFunctionData::DoubleByValue: case VMFunctionData::DoubleByRef: MOZ_CRASH("NYI: x64 callVM should not be used with 128bits values."); } } // Copy the implicit outparam, if any. if (outReg != InvalidReg) { masm.passABIArg(outReg); } masm.callWithABI(nativeFun, MoveOp::GENERAL, CheckUnsafeCallWithABI::DontCheckHasExitFrame); if (!generateTLExitVM(masm, f)) { return false; } // Test for failure. switch (f.failType()) { case Type_Object: masm.branchTestPtr(Assembler::Zero, rax, rax, masm.failureLabel()); break; case Type_Bool: masm.testb(rax, rax); masm.j(Assembler::Zero, masm.failureLabel()); break; case Type_Void: break; default: MOZ_CRASH("unknown failure kind"); } // Load the outparam and free any allocated stack. switch (f.outParam) { case Type_Handle: masm.popRooted(f.outParamRootType, ReturnReg, JSReturnOperand); break; case Type_Value: masm.loadValue(Address(esp, 0), JSReturnOperand); masm.freeStack(sizeof(Value)); break; case Type_Int32: masm.load32(Address(esp, 0), ReturnReg); masm.freeStack(sizeof(uintptr_t)); break; case Type_Bool: masm.load8ZeroExtend(Address(esp, 0), ReturnReg); masm.freeStack(sizeof(uintptr_t)); break; case Type_Double: MOZ_ASSERT(JitOptions.supportsFloatingPoint); masm.loadDouble(Address(esp, 0), ReturnDoubleReg); masm.freeStack(sizeof(double)); break; case Type_Pointer: masm.loadPtr(Address(esp, 0), ReturnReg); masm.freeStack(sizeof(uintptr_t)); break; default: MOZ_ASSERT(f.outParam == Type_Void); break; } // Until C++ code is instrumented against Spectre, prevent speculative // execution from returning any private data. if (f.returnsData() && JitOptions.spectreJitToCxxCalls) { masm.speculationBarrier(); } masm.leaveExitFrame(); masm.retn(Imm32(sizeof(ExitFrameLayout) + f.explicitStackSlots() * sizeof(void*) + f.extraValuesToPop * sizeof(Value))); return true; } uint32_t JitRuntime::generatePreBarrier(JSContext* cx, MacroAssembler& masm, MIRType type) { uint32_t offset = startTrampolineCode(masm); static_assert(PreBarrierReg == rdx); Register temp1 = rax; Register temp2 = rbx; Register temp3 = rcx; masm.push(temp1); masm.push(temp2); masm.push(temp3); Label noBarrier; masm.emitPreBarrierFastPath(cx->runtime(), type, temp1, temp2, temp3, &noBarrier); // Call into C++ to mark this GC thing. masm.pop(temp3); masm.pop(temp2); masm.pop(temp1); LiveRegisterSet regs = LiveRegisterSet(GeneralRegisterSet(Registers::VolatileMask), FloatRegisterSet(FloatRegisters::VolatileMask)); masm.PushRegsInMask(regs); masm.mov(ImmPtr(cx->runtime()), rcx); masm.setupUnalignedABICall(rax); masm.passABIArg(rcx); masm.passABIArg(rdx); masm.callWithABI(JitMarkFunction(type)); masm.PopRegsInMask(regs); masm.ret(); masm.bind(&noBarrier); masm.pop(temp3); masm.pop(temp2); masm.pop(temp1); masm.ret(); return offset; } void JitRuntime::generateExceptionTailStub(MacroAssembler& masm, Label* profilerExitTail) { exceptionTailOffset_ = startTrampolineCode(masm); masm.bind(masm.failureLabel()); masm.handleFailureWithHandlerTail(profilerExitTail); } void JitRuntime::generateBailoutTailStub(MacroAssembler& masm, Label* bailoutTail) { bailoutTailOffset_ = startTrampolineCode(masm); masm.bind(bailoutTail); masm.generateBailoutTail(rdx, r9); } void JitRuntime::generateProfilerExitFrameTailStub(MacroAssembler& masm, Label* profilerExitTail) { profilerExitFrameTailOffset_ = startTrampolineCode(masm); masm.bind(profilerExitTail); Register scratch1 = r8; Register scratch2 = r9; Register scratch3 = r10; Register scratch4 = r11; // // The code generated below expects that the current stack pointer points // to an Ion or Baseline frame, at the state it would be immediately // before a ret(). Thus, after this stub's business is done, it executes // a ret() and returns directly to the caller script, on behalf of the // callee script that jumped to this code. // // Thus the expected stack is: // // StackPointer ----+ // v // ..., ActualArgc, CalleeToken, Descriptor, ReturnAddr // MEM-HI MEM-LOW // // // The generated jitcode is responsible for overwriting the // jitActivation->lastProfilingFrame field with a pointer to the previous // Ion or Baseline jit-frame that was pushed before this one. It is also // responsible for overwriting jitActivation->lastProfilingCallSite with // the return address into that frame. The frame could either be an // immediate "caller" frame, or it could be a frame in a previous // JitActivation (if the current frame was entered from C++, and the C++ // was entered by some caller jit-frame further down the stack). // // So this jitcode is responsible for "walking up" the jit stack, finding // the previous Ion or Baseline JS frame, and storing its address and the // return address into the appropriate fields on the current jitActivation. // // There are a fixed number of different path types that can lead to the // current frame, which is either a baseline or ion frame: // // // ^ // | // ^--- Ion // | // ^--- Baseline Stub <---- Baseline // | // ^--- Argument Rectifier // | ^ // | | // | ^--- Ion // | | // | ^--- Baseline Stub <---- Baseline // | // ^--- Entry Frame (From C++) // Register actReg = scratch4; masm.loadJSContext(actReg); masm.loadPtr(Address(actReg, offsetof(JSContext, profilingActivation_)), actReg); Address lastProfilingFrame(actReg, JitActivation::offsetOfLastProfilingFrame()); Address lastProfilingCallSite(actReg, JitActivation::offsetOfLastProfilingCallSite()); #ifdef DEBUG // Ensure that frame we are exiting is current lastProfilingFrame { masm.loadPtr(lastProfilingFrame, scratch1); Label checkOk; masm.branchPtr(Assembler::Equal, scratch1, ImmWord(0), &checkOk); masm.branchPtr(Assembler::Equal, StackPointer, scratch1, &checkOk); masm.assumeUnreachable( "Mismatch between stored lastProfilingFrame and current stack " "pointer."); masm.bind(&checkOk); } #endif // Load the frame descriptor into |scratch1|, figure out what to do depending // on its type. masm.loadPtr(Address(StackPointer, JitFrameLayout::offsetOfDescriptor()), scratch1); // Going into the conditionals, we will have: // FrameDescriptor.size in scratch1 // FrameDescriptor.type in scratch2 masm.movePtr(scratch1, scratch2); masm.rshiftPtr(Imm32(FRAMESIZE_SHIFT), scratch1); masm.and32(Imm32((1 << FRAMETYPE_BITS) - 1), scratch2); // Handling of each case is dependent on FrameDescriptor.type Label handle_IonJS; Label handle_BaselineStub; Label handle_Rectifier; Label handle_IonICCall; Label handle_Entry; Label end; masm.branch32(Assembler::Equal, scratch2, Imm32(FrameType::IonJS), &handle_IonJS); masm.branch32(Assembler::Equal, scratch2, Imm32(FrameType::BaselineJS), &handle_IonJS); masm.branch32(Assembler::Equal, scratch2, Imm32(FrameType::BaselineStub), &handle_BaselineStub); masm.branch32(Assembler::Equal, scratch2, Imm32(FrameType::Rectifier), &handle_Rectifier); masm.branch32(Assembler::Equal, scratch2, Imm32(FrameType::IonICCall), &handle_IonICCall); masm.branch32(Assembler::Equal, scratch2, Imm32(FrameType::CppToJSJit), &handle_Entry); // The WasmToJSJit is just another kind of entry masm.branch32(Assembler::Equal, scratch2, Imm32(FrameType::WasmToJSJit), &handle_Entry); masm.assumeUnreachable( "Invalid caller frame type when exiting from Ion frame."); // // FrameType::IonJS // // Stack layout: // ... // Ion-Descriptor // Prev-FP ---> Ion-ReturnAddr // ... previous frame data ... |- Descriptor.Size // ... arguments ... | // ActualArgc | // CalleeToken |- JitFrameLayout::Size() // Descriptor | // FP -----> ReturnAddr | // masm.bind(&handle_IonJS); { // returning directly to an IonJS frame. Store return addr to frame // in lastProfilingCallSite. masm.loadPtr(Address(StackPointer, JitFrameLayout::offsetOfReturnAddress()), scratch2); masm.storePtr(scratch2, lastProfilingCallSite); // Store return frame in lastProfilingFrame. // scratch2 := StackPointer + Descriptor.size*1 + JitFrameLayout::Size(); masm.lea(Operand(StackPointer, scratch1, TimesOne, JitFrameLayout::Size()), scratch2); masm.storePtr(scratch2, lastProfilingFrame); masm.ret(); } // // FrameType::BaselineStub // // Look past the stub and store the frame pointer to // the baselineJS frame prior to it. // // Stack layout: // ... // BL-Descriptor // Prev-FP ---> BL-ReturnAddr // +-----> BL-PrevFramePointer // | ... BL-FrameData ... // | BLStub-Descriptor // | BLStub-ReturnAddr // | BLStub-StubPointer | // +------ BLStub-SavedFramePointer |- Descriptor.Size // ... arguments ... | // ActualArgc | // CalleeToken |- JitFrameLayout::Size() // Descriptor | // FP -----> ReturnAddr | // // We take advantage of the fact that the stub frame saves the frame // pointer pointing to the baseline frame, so a bunch of calculation can // be avoided. // masm.bind(&handle_BaselineStub); { BaseIndex stubFrameReturnAddr( StackPointer, scratch1, TimesOne, JitFrameLayout::Size() + BaselineStubFrameLayout::offsetOfReturnAddress()); masm.loadPtr(stubFrameReturnAddr, scratch2); masm.storePtr(scratch2, lastProfilingCallSite); BaseIndex stubFrameSavedFramePtr( StackPointer, scratch1, TimesOne, JitFrameLayout::Size() - (2 * sizeof(void*))); masm.loadPtr(stubFrameSavedFramePtr, scratch2); masm.addPtr(Imm32(sizeof(void*)), scratch2); // Skip past BL-PrevFramePtr masm.storePtr(scratch2, lastProfilingFrame); masm.ret(); } // // FrameType::Rectifier // // The rectifier frame can be preceded by either an IonJS, a BaselineStub, // or a CppToJSJit/WasmToJSJit frame. // // Stack layout if caller of rectifier was Ion or CppToJSJit/WasmToJSJit: // // Ion-Descriptor // Ion-ReturnAddr // ... ion frame data ... |- Rect-Descriptor.Size // < COMMON LAYOUT > // // Stack layout if caller of rectifier was Baseline: // // BL-Descriptor // Prev-FP ---> BL-ReturnAddr // +-----> BL-SavedFramePointer // | ... baseline frame data ... // | BLStub-Descriptor // | BLStub-ReturnAddr // | BLStub-StubPointer | // +------ BLStub-SavedFramePointer |- Rect-Descriptor.Size // ... args to rectifier ... | // < COMMON LAYOUT > // // Common stack layout: // // ActualArgc | // CalleeToken |- IonRectitiferFrameLayout::Size() // Rect-Descriptor | // Rect-ReturnAddr | // ... rectifier data & args ... |- Descriptor.Size // ActualArgc | // CalleeToken |- JitFrameLayout::Size() // Descriptor | // FP -----> ReturnAddr | // masm.bind(&handle_Rectifier); { // scratch2 := StackPointer + Descriptor.size + JitFrameLayout::Size() masm.lea(Operand(StackPointer, scratch1, TimesOne, JitFrameLayout::Size()), scratch2); masm.loadPtr(Address(scratch2, RectifierFrameLayout::offsetOfDescriptor()), scratch3); masm.movePtr(scratch3, scratch1); masm.and32(Imm32((1 << FRAMETYPE_BITS) - 1), scratch3); masm.rshiftPtr(Imm32(FRAMESIZE_SHIFT), scratch1); // Now |scratch1| contains Rect-Descriptor.Size // and |scratch2| points to Rectifier frame // and |scratch3| contains Rect-Descriptor.Type masm.assertRectifierFrameParentType(scratch3); // Check for either Ion or something else frame. Label notIonFrame; masm.branch32(Assembler::NotEqual, scratch3, Imm32(FrameType::IonJS), ¬IonFrame); // Handle Rectifier <- IonJS // scratch3 := RectFrame[ReturnAddr] masm.loadPtr( Address(scratch2, RectifierFrameLayout::offsetOfReturnAddress()), scratch3); masm.storePtr(scratch3, lastProfilingCallSite); // scratch3 := RectFrame + Rect-Descriptor.Size + // RectifierFrameLayout::Size() masm.lea( Operand(scratch2, scratch1, TimesOne, RectifierFrameLayout::Size()), scratch3); masm.storePtr(scratch3, lastProfilingFrame); masm.ret(); masm.bind(¬IonFrame); // Check for either BaselineStub or a CppToJSJit/WasmToJSJit entry // frame. masm.branch32(Assembler::NotEqual, scratch3, Imm32(FrameType::BaselineStub), &handle_Entry); // Handle Rectifier <- BaselineStub <- BaselineJS BaseIndex stubFrameReturnAddr( scratch2, scratch1, TimesOne, RectifierFrameLayout::Size() + BaselineStubFrameLayout::offsetOfReturnAddress()); masm.loadPtr(stubFrameReturnAddr, scratch3); masm.storePtr(scratch3, lastProfilingCallSite); BaseIndex stubFrameSavedFramePtr( scratch2, scratch1, TimesOne, RectifierFrameLayout::Size() - (2 * sizeof(void*))); masm.loadPtr(stubFrameSavedFramePtr, scratch3); masm.addPtr(Imm32(sizeof(void*)), scratch3); masm.storePtr(scratch3, lastProfilingFrame); masm.ret(); } // FrameType::IonICCall // // The caller is always an IonJS frame. // // Ion-Descriptor // Ion-ReturnAddr // ... ion frame data ... |- CallFrame-Descriptor.Size // StubCode | // ICCallFrame-Descriptor |- IonICCallFrameLayout::Size() // ICCallFrame-ReturnAddr | // ... call frame data & args ... |- Descriptor.Size // ActualArgc | // CalleeToken |- JitFrameLayout::Size() // Descriptor | // FP -----> ReturnAddr | masm.bind(&handle_IonICCall); { // scratch2 := StackPointer + Descriptor.size + JitFrameLayout::Size() masm.lea(Operand(StackPointer, scratch1, TimesOne, JitFrameLayout::Size()), scratch2); // scratch3 := ICCallFrame-Descriptor.Size masm.loadPtr(Address(scratch2, IonICCallFrameLayout::offsetOfDescriptor()), scratch3); #ifdef DEBUG // Assert previous frame is an IonJS frame. masm.movePtr(scratch3, scratch1); masm.and32(Imm32((1 << FRAMETYPE_BITS) - 1), scratch1); { Label checkOk; masm.branch32(Assembler::Equal, scratch1, Imm32(FrameType::IonJS), &checkOk); masm.assumeUnreachable("IonICCall frame must be preceded by IonJS frame"); masm.bind(&checkOk); } #endif masm.rshiftPtr(Imm32(FRAMESIZE_SHIFT), scratch3); // lastProfilingCallSite := ICCallFrame-ReturnAddr masm.loadPtr( Address(scratch2, IonICCallFrameLayout::offsetOfReturnAddress()), scratch1); masm.storePtr(scratch1, lastProfilingCallSite); // lastProfilingFrame := ICCallFrame + ICCallFrame-Descriptor.Size + // IonICCallFrameLayout::Size() masm.lea( Operand(scratch2, scratch3, TimesOne, IonICCallFrameLayout::Size()), scratch1); masm.storePtr(scratch1, lastProfilingFrame); masm.ret(); } // // FrameType::CppToJSJit / FrameType::WasmToJSJit // // If at an entry frame, store null into both fields. // A fast-path wasm->jit transition frame is an entry frame from the point // of view of the JIT. // masm.bind(&handle_Entry); { masm.movePtr(ImmPtr(nullptr), scratch1); masm.storePtr(scratch1, lastProfilingCallSite); masm.storePtr(scratch1, lastProfilingFrame); masm.ret(); } }