1/*
2 * Copyright (C) 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27
28#include "ExecutableAllocator.h"
29
30#if ENABLE(ASSEMBLER)
31
32namespace JSC {
33
34size_t ExecutableAllocator::pageSize = 0;
35
36#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
37void ExecutableAllocator::reprotectRegion(void* start, size_t size, ProtectionSeting setting)
38{
39 if (!pageSize)
40 intializePageSize();
41
42 // Calculate the start of the page containing this region,
43 // and account for this extra memory within size.
44 intptr_t startPtr = reinterpret_cast<intptr_t>(start);
45 intptr_t pageStartPtr = startPtr & ~(pageSize - 1);
46 void* pageStart = reinterpret_cast<void*>(pageStartPtr);
47 size += (startPtr - pageStartPtr);
48
49 // Round size up
50 size += (pageSize - 1);
51 size &= ~(pageSize - 1);
52
53 mprotect(pageStart, size, (setting == Writable) ? PROTECTION_FLAGS_RW : PROTECTION_FLAGS_RX);
54}
55#endif
56
57}
58
59#endif // HAVE(ASSEMBLER)
60

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/jit/ExecutableAllocator.cpp