blob: 0e99f11deb1c79a834a5a26cb69bf60f3126be25 [file] [log] [blame]
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
*
* Copyright (C) 2008 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 "mozilla/DebugOnly.h"
#include "mozilla/TaggedAnonymousMemory.h"
#include <errno.h>
#include <sys/mman.h>
#include <unistd.h>
#include "jit/ExecutableAllocator.h"
#include "js/Utility.h"
using namespace js::jit;
// TODO: Starboardize.
size_t
ExecutableAllocator::determinePageSize()
{
return getpagesize();
}
// TODO: Starboardize. PROT_READ, etc. flags are not defined in Starboard.
void*
js::jit::AllocateExecutableMemory(void* addr, size_t bytes, unsigned permissions, const char* tag,
size_t pageSize)
{
MOZ_ASSERT(bytes % pageSize == 0);
void* p = MozTaggedAnonymousMmap(addr, bytes, permissions, MAP_PRIVATE | MAP_ANON, -1, 0, tag);
return p == MAP_FAILED ? nullptr : p;
}
// TODO: Starboardize.
void
js::jit::DeallocateExecutableMemory(void* addr, size_t bytes, size_t pageSize)
{
MOZ_ASSERT(bytes % pageSize == 0);
mozilla::DebugOnly<int> result = munmap(addr, bytes);
MOZ_ASSERT(!result || errno == ENOMEM);
}
ExecutablePool::Allocation
ExecutableAllocator::systemAlloc(size_t n)
{
void* allocation = AllocateExecutableMemory(nullptr, n, initialProtectionFlags(Executable),
"js-jit-code", pageSize);
ExecutablePool::Allocation alloc = { reinterpret_cast<char*>(allocation), n };
return alloc;
}
void
ExecutableAllocator::systemRelease(const ExecutablePool::Allocation& alloc)
{
DeallocateExecutableMemory(alloc.pages, alloc.size, pageSize);
}
// TODO: Starboardize. PROT_READ, etc. flags are not defined in Starboard.
static const unsigned FLAGS_RW = PROT_READ | PROT_WRITE;
static const unsigned FLAGS_RX = PROT_READ | PROT_EXEC;
// TODO: Starboardize.
void
ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSetting setting)
{
MOZ_ASSERT(nonWritableJitCode);
MOZ_ASSERT(pageSize);
// Calculate the start of the page containing this region,
// and account for this extra memory within size.
intptr_t startPtr = reinterpret_cast<intptr_t>(start);
intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
void* pageStart = reinterpret_cast<void*>(pageStartPtr);
size += (startPtr - pageStartPtr);
// Round size up
size += (pageSize - 1);
size &= ~(pageSize - 1);
mprotect(pageStart, size, (setting == Writable) ? FLAGS_RW : FLAGS_RX);
}
// TODO: Starboardize.
/* static */ unsigned
ExecutableAllocator::initialProtectionFlags(ProtectionSetting protection)
{
if (!nonWritableJitCode)
return FLAGS_RW | FLAGS_RX;
return (protection == Writable) ? FLAGS_RW : FLAGS_RX;
}