/* * Copyright (C) 2016-2018 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 "WasmBinding.h" #if ENABLE(WEBASSEMBLY) #include "CCallHelpers.h" #include "JSCInlines.h" #include "LinkBuffer.h" #include "WasmInstance.h" namespace JSC { namespace Wasm { using JIT = CCallHelpers; Expected<MacroAssemblerCodeRef<WasmEntryPtrTag>, BindingFailure> wasmToWasm(unsigned importIndex) { // FIXME: Consider uniquify the stubs based on signature + index to see if this saves memory. // https://bugs.webkit.org/show_bug.cgi?id=184157 const PinnedRegisterInfo& pinnedRegs = PinnedRegisterInfo::get(); JIT jit; GPRReg scratch = GPRInfo::nonPreservedNonArgumentGPR0; GPRReg baseMemory = pinnedRegs.baseMemoryPointer; ASSERT(baseMemory != scratch); const auto& sizeRegs = pinnedRegs.sizeRegisters; ASSERT(sizeRegs.size() >= 1); ASSERT(sizeRegs[0].sizeRegister != baseMemory); ASSERT(sizeRegs[0].sizeRegister != scratch); GPRReg sizeRegAsScratch = sizeRegs[0].sizeRegister; // B3's call codegen ensures that the JSCell is a WebAssemblyFunction. jit.loadWasmContextInstance(sizeRegAsScratch); // Old Instance* // Get the callee's Wasm::Instance and set it as WasmContext's instance. The caller will take care of restoring its own Instance. jit.loadPtr(JIT::Address(sizeRegAsScratch, Instance::offsetOfTargetInstance(importIndex)), baseMemory); // Instance*. // While we're accessing that cacheline, also get the wasm entrypoint so we can tail call to it below. jit.loadPtr(JIT::Address(sizeRegAsScratch, Instance::offsetOfWasmEntrypointLoadLocation(importIndex)), scratch); jit.storeWasmContextInstance(baseMemory); jit.loadPtr(JIT::Address(sizeRegAsScratch, Instance::offsetOfCachedStackLimit()), sizeRegAsScratch); jit.storePtr(sizeRegAsScratch, JIT::Address(baseMemory, Instance::offsetOfCachedStackLimit())); // FIXME the following code assumes that all Wasm::Instance have the same pinned registers. https://bugs.webkit.org/show_bug.cgi?id=162952 // Set up the callee's baseMemory register as well as the memory size registers. ASSERT(!sizeRegs[0].sizeOffset); // The following code assumes we start at 0, and calculates subsequent size registers relative to 0. jit.loadPtr(JIT::Address(baseMemory, Wasm::Instance::offsetOfCachedMemorySize()), sizeRegs[0].sizeRegister); // Memory size. jit.loadPtr(JIT::Address(baseMemory, Wasm::Instance::offsetOfCachedMemory()), baseMemory); // Wasm::Memory::void*. for (unsigned i = 1; i < sizeRegs.size(); ++i) { ASSERT(sizeRegs[i].sizeRegister != baseMemory); ASSERT(sizeRegs[i].sizeRegister != scratch); jit.add64(JIT::TrustedImm32(-sizeRegs[i].sizeOffset), sizeRegs[0].sizeRegister, sizeRegs[i].sizeRegister); } // Tail call into the callee WebAssembly function. jit.loadPtr(scratch, scratch); if (Options::usePoisoning()) jit.xorPtr(JIT::TrustedImmPtr(g_JITCodePoison), scratch); jit.jump(scratch, WasmEntryPtrTag); LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID, JITCompilationCanFail); if (UNLIKELY(patchBuffer.didFailToAllocate())) return makeUnexpected(BindingFailure::OutOfMemory); return FINALIZE_CODE(patchBuffer, WasmEntryPtrTag, "WebAssembly->WebAssembly import[%i]", importIndex); } } } // namespace JSC::Wasm #endif // ENABLE(WEBASSEMBLY)