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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
*
* Copyright 2014 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef wasm_signal_handlers_h
#define wasm_signal_handlers_h
#include "mozilla/Attributes.h"
#include "js/ProfilingFrameIterator.h"
#include "wasm/WasmProcess.h"
namespace js {
namespace wasm {
using RegisterState = JS::ProfilingFrameIterator::RegisterState;
// This function performs the low-overhead signal handler initialization that we
// want to do eagerly to ensure a more-deterministic global process state. This
// is especially relevant for signal handlers since handler ordering depends on
// installation order: the wasm signal handler must run *before* the other crash
// handlers (ds/MemoryProtectionExceptionHandler.h and breakpad) and since POSIX
// signal handlers work LIFO, this function needs to be called at the end of the
// startup process, after the other two handlers have been installed. Currently,
// this is achieved by having JSRuntime() call this function. There can be
// multiple JSRuntimes per process so this function can thus be called multiple
// times, having no effect after the first call.
void EnsureEagerProcessSignalHandlers();
// Assuming EnsureEagerProcessSignalHandlers() has already been called,
// this function performs the full installation of signal handlers which must
// be performed per-thread/JSContext. This operation may incur some overhead and
// so should be done only when needed to use wasm. Currently, this is done in
// wasm::HasPlatformSupport() which is called when deciding whether to expose
// the 'WebAssembly' object on the global object.
bool EnsureFullSignalHandlers(JSContext* cx);
// Return whether, with the given simulator register state, a memory access to
// 'addr' of size 'numBytes' needs to trap and, if so, where the simulator
// should redirect pc to.
bool MemoryAccessTraps(const RegisterState& regs, uint8_t* addr,
uint32_t numBytes, uint8_t** newPC);
// Return whether, with the given simulator register state, an illegal
// instruction fault is expected and, if so, the value of the next PC.
bool HandleIllegalInstruction(const RegisterState& regs, uint8_t** newPC);
} // namespace wasm
} // namespace js
#endif // wasm_signal_handlers_h