Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/OSAllocatorPosix.cpp

-/*
- * Copyright (C) 2010 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. AND ITS CONTRIBUTORS ``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 ITS 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 "OSAllocator.h"
-
-#if OS(UNIX)
-
-#include "PageAllocation.h"
-#include <errno.h>
-#include <sys/mman.h>
-#include <wtf/Assertions.h>
-#include <wtf/UnusedParam.h>
-
-namespace WTF {
-
-void* OSAllocator::reserveUncommitted(size_t bytes, Usage usage, bool writable, bool executable, bool includesGuardPages)
-{
-#if OS(QNX)
-    // Reserve memory with PROT_NONE and MAP_LAZY so it isn't committed now.
-    void* result = mmap(0, bytes, PROT_NONE, MAP_LAZY | MAP_PRIVATE | MAP_ANON, -1, 0);
-    if (result == MAP_FAILED)
-        CRASH();
-#elif OS(LINUX)
-    UNUSED_PARAM(usage);
-    UNUSED_PARAM(writable);
-    UNUSED_PARAM(executable);
-    UNUSED_PARAM(includesGuardPages);
-
-    void* result = mmap(0, bytes, PROT_NONE, MAP_NORESERVE | MAP_PRIVATE | MAP_ANON, -1, 0);
-    if (result == MAP_FAILED)
-        CRASH();
-    madvise(result, bytes, MADV_DONTNEED);
-#else
-    void* result = reserveAndCommit(bytes, usage, writable, executable, includesGuardPages);
-#if HAVE(MADV_FREE_REUSE)
-    // To support the "reserve then commit" model, we have to initially decommit.
-    while (madvise(result, bytes, MADV_FREE_REUSABLE) == -1 && errno == EAGAIN) { }
-#endif
-
-#endif // OS(QNX)
-
-    return result;
-}
-
-void* OSAllocator::reserveAndCommit(size_t bytes, Usage usage, bool writable, bool executable, bool includesGuardPages)
-{
-    // All POSIX reservations start out logically committed.
-    int protection = PROT_READ;
-    if (writable)
-        protection |= PROT_WRITE;
-    if (executable)
-        protection |= PROT_EXEC;
-
-    int flags = MAP_PRIVATE | MAP_ANON;
-
-#if OS(DARWIN)
-    int fd = usage;
-#else
-    UNUSED_PARAM(usage);
-    int fd = -1;
-#endif
-
-    void* result = 0;
-#if (OS(DARWIN) && CPU(X86_64))
-    if (executable) {
-        ASSERT(includesGuardPages);
-        // Cook up an address to allocate at, using the following recipe:
-        //   17 bits of zero, stay in userspace kids.
-        //   26 bits of randomness for ASLR.
-        //   21 bits of zero, at least stay aligned within one level of the pagetables.
-        //
-        // But! - as a temporary workaround for some plugin problems (rdar://problem/6812854),
-        // for now instead of 2^26 bits of ASLR lets stick with 25 bits of randomization plus
-        // 2^24, which should put up somewhere in the middle of userspace (in the address range
-        // 0x200000000000 .. 0x5fffffffffff).
-        intptr_t randomLocation = 0;
-        randomLocation = arc4random() & ((1 << 25) - 1);
-        randomLocation += (1 << 24);
-        randomLocation <<= 21;
-        result = reinterpret_cast<void*>(randomLocation);
-    }
-#endif
-
-    result = mmap(result, bytes, protection, flags, fd, 0);
-    if (result == MAP_FAILED) {
-#if ENABLE(LLINT)
-        if (executable)
-            result = 0;
-        else
-#endif
-            CRASH();
-    }
-    if (result && includesGuardPages) {
-        // We use mmap to remap the guardpages rather than using mprotect as
-        // mprotect results in multiple references to the code region.  This
-        // breaks the madvise based mechanism we use to return physical memory
-        // to the OS.
-        mmap(result, pageSize(), PROT_NONE, MAP_FIXED | MAP_PRIVATE | MAP_ANON, fd, 0);
-        mmap(static_cast<char*>(result) + bytes - pageSize(), pageSize(), PROT_NONE, MAP_FIXED | MAP_PRIVATE | MAP_ANON, fd, 0);
-    }
-    return result;
-}
-
-void OSAllocator::commit(void* address, size_t bytes, bool writable, bool executable)
-{
-#if OS(QNX)
-    int protection = PROT_READ;
-    if (writable)
-        protection |= PROT_WRITE;
-    if (executable)
-        protection |= PROT_EXEC;
-    if (MAP_FAILED == mmap(address, bytes, protection, MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0))
-        CRASH();
-#elif OS(LINUX)
-    int protection = PROT_READ;
-    if (writable)
-        protection |= PROT_WRITE;
-    if (executable)
-        protection |= PROT_EXEC;
-    if (mprotect(address, bytes, protection))
-        CRASH();
-    madvise(address, bytes, MADV_WILLNEED);
-#elif HAVE(MADV_FREE_REUSE)
-    UNUSED_PARAM(writable);
-    UNUSED_PARAM(executable);
-    while (madvise(address, bytes, MADV_FREE_REUSE) == -1 && errno == EAGAIN) { }
-#else
-    // Non-MADV_FREE_REUSE reservations automatically commit on demand.
-    UNUSED_PARAM(address);
-    UNUSED_PARAM(bytes);
-    UNUSED_PARAM(writable);
-    UNUSED_PARAM(executable);
-#endif
-}
-
-void OSAllocator::decommit(void* address, size_t bytes)
-{
-#if OS(QNX)
-    // Use PROT_NONE and MAP_LAZY to decommit the pages.
-    mmap(address, bytes, PROT_NONE, MAP_FIXED | MAP_LAZY | MAP_PRIVATE | MAP_ANON, -1, 0);
-#elif OS(LINUX)
-    madvise(address, bytes, MADV_DONTNEED);
-    if (mprotect(address, bytes, PROT_NONE))
-        CRASH();
-#elif HAVE(MADV_FREE_REUSE)
-    while (madvise(address, bytes, MADV_FREE_REUSABLE) == -1 && errno == EAGAIN) { }
-#elif HAVE(MADV_FREE)
-    while (madvise(address, bytes, MADV_FREE) == -1 && errno == EAGAIN) { }
-#elif HAVE(MADV_DONTNEED)
-    while (madvise(address, bytes, MADV_DONTNEED) == -1 && errno == EAGAIN) { }
-#else
-    UNUSED_PARAM(address);
-    UNUSED_PARAM(bytes);
-#endif
-}
-
-void OSAllocator::releaseDecommitted(void* address, size_t bytes)
-{
-    int result = munmap(address, bytes);
-    if (result == -1)
-        CRASH();
-}
-
-} // namespace WTF
-
-#endif // OS(UNIX)