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/*
* Copyright (C) 2017 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "WasmThunks.h"
#if ENABLE(WEBASSEMBLY)
#include "CCallHelpers.h"
#include "FrameTracers.h"
#include "HeapCellInlines.h"
#include "JITExceptions.h"
#include "JSWebAssemblyInstance.h"
#include "JSWebAssemblyRuntimeError.h"
#include "LinkBuffer.h"
#include "ScratchRegisterAllocator.h"
#include "WasmContext.h"
#include "WasmExceptionType.h"
#include "WasmOMGPlan.h"
namespace JSC { namespace Wasm {
MacroAssemblerCodeRef throwExceptionFromWasmThunkGenerator(const AbstractLocker&)
{
CCallHelpers jit;
// The thing that jumps here must move ExceptionType into the argumentGPR1 before jumping here.
// We're allowed to use temp registers here. We are not allowed to use callee saves.
jit.loadWasmContext(GPRInfo::argumentGPR2);
jit.loadPtr(CCallHelpers::Address(GPRInfo::argumentGPR2, Context::offsetOfVM()), GPRInfo::argumentGPR0);
jit.copyCalleeSavesToVMEntryFrameCalleeSavesBuffer(GPRInfo::argumentGPR0);
jit.move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
CCallHelpers::Call call = jit.call();
jit.jump(GPRInfo::returnValueGPR);
jit.breakpoint(); // We should not reach this.
void* (*throwWasmException)(ExecState*, Wasm::ExceptionType, Wasm::Context*) = [] (ExecState* exec, Wasm::ExceptionType type, Wasm::Context* wasmContext) -> void* {
VM* vm = wasmContext->vm();
NativeCallFrameTracer tracer(vm, exec);
{
auto throwScope = DECLARE_THROW_SCOPE(*vm);
JSGlobalObject* globalObject = wasmContext->globalObject();
JSObject* error;
if (type == ExceptionType::StackOverflow)
error = createStackOverflowError(exec, globalObject);
else
error = JSWebAssemblyRuntimeError::create(exec, *vm, globalObject->WebAssemblyRuntimeErrorStructure(), Wasm::errorMessageForExceptionType(type));
throwException(exec, throwScope, error);
}
genericUnwind(vm, exec);
ASSERT(!!vm->callFrameForCatch);
ASSERT(!!vm->targetMachinePCForThrow);
// FIXME: We could make this better:
// This is a total hack, but the llint (both op_catch and handleUncaughtException)
// require a cell in the callee field to load the VM. (The baseline JIT does not require
// this since it is compiled with a constant VM pointer.) We could make the calling convention
// for exceptions first load callFrameForCatch info call frame register before jumping
// to the exception handler. If we did this, we could remove this terrible hack.
// https://bugs.webkit.org/show_bug.cgi?id=170440
bitwise_cast<uint64_t*>(exec)[CallFrameSlot::callee] = bitwise_cast<uint64_t>(wasmContext->webAssemblyToJSCallee());
return vm->targetMachinePCForThrow;
};
LinkBuffer linkBuffer(jit, GLOBAL_THUNK_ID);
linkBuffer.link(call, throwWasmException);
return FINALIZE_CODE(linkBuffer, ("Throw exception from Wasm"));
}
MacroAssemblerCodeRef throwStackOverflowFromWasmThunkGenerator(const AbstractLocker& locker)
{
CCallHelpers jit;
int32_t stackSpace = WTF::roundUpToMultipleOf(stackAlignmentBytes(), RegisterSet::calleeSaveRegisters().numberOfSetRegisters() * sizeof(Register));
ASSERT(static_cast<unsigned>(stackSpace) < Options::softReservedZoneSize());
jit.addPtr(CCallHelpers::TrustedImm32(-stackSpace), GPRInfo::callFrameRegister, MacroAssembler::stackPointerRegister);
jit.move(CCallHelpers::TrustedImm32(static_cast<uint32_t>(ExceptionType::StackOverflow)), GPRInfo::argumentGPR1);
auto jumpToExceptionHandler = jit.jump();
LinkBuffer linkBuffer(jit, GLOBAL_THUNK_ID);
linkBuffer.link(jumpToExceptionHandler, CodeLocationLabel(Thunks::singleton().stub(locker, throwExceptionFromWasmThunkGenerator).code()));
return FINALIZE_CODE(linkBuffer, ("Throw stack overflow from Wasm"));
}
MacroAssemblerCodeRef triggerOMGTierUpThunkGenerator(const AbstractLocker&)
{
// We expect that the user has already put the function index into GPRInfo::argumentGPR1
CCallHelpers jit;
const unsigned extraPaddingBytes = 0;
RegisterSet registersToSpill = RegisterSet::allRegisters();
registersToSpill.exclude(RegisterSet::registersToNotSaveForCCall());
#if CPU(ARM64)
// We also want to spill x30 since that holds our return pc.
registersToSpill.set(ARM64Registers::x30);
#endif
unsigned numberOfStackBytesUsedForRegisterPreservation = ScratchRegisterAllocator::preserveRegistersToStackForCall(jit, registersToSpill, extraPaddingBytes);
jit.loadWasmContext(GPRInfo::argumentGPR0);
jit.move(MacroAssembler::TrustedImmPtr(reinterpret_cast<void*>(runOMGPlanForIndex)), GPRInfo::argumentGPR2);
jit.call(GPRInfo::argumentGPR2);
ScratchRegisterAllocator::restoreRegistersFromStackForCall(jit, registersToSpill, RegisterSet(), numberOfStackBytesUsedForRegisterPreservation, extraPaddingBytes);
jit.ret();
LinkBuffer linkBuffer(jit, GLOBAL_THUNK_ID);
return FINALIZE_CODE(linkBuffer, ("Trigger OMG tier up"));
}
static Thunks* thunks;
void Thunks::initialize()
{
thunks = new Thunks;
}
Thunks& Thunks::singleton()
{
ASSERT(thunks);
return *thunks;
}
MacroAssemblerCodeRef Thunks::stub(ThunkGenerator generator)
{
auto locker = holdLock(m_lock);
return stub(locker, generator);
}
MacroAssemblerCodeRef Thunks::stub(const AbstractLocker& locker, ThunkGenerator generator)
{
ASSERT(!!generator);
{
auto addResult = m_stubs.add(generator, MacroAssemblerCodeRef());
if (!addResult.isNewEntry)
return addResult.iterator->value;
}
MacroAssemblerCodeRef code = generator(locker);
// We specifically don't use the iterator here to allow generator to recursively change m_stubs.
m_stubs.set(generator, code);
return code;
}
MacroAssemblerCodeRef Thunks::existingStub(ThunkGenerator generator)
{
auto locker = holdLock(m_lock);
auto iter = m_stubs.find(generator);
if (iter != m_stubs.end())
return iter->value;
return MacroAssemblerCodeRef();
}
} } // namespace JSC::Wasm
#endif // ENABLE(WEBASSEMBLY)
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