1/*
2 * Copyright (C) 2019 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#include "JSCConfig.h"
28
29#include <wtf/ResourceUsage.h>
30#include <wtf/StdLibExtras.h>
31
32#if OS(DARWIN)
33#include <mach/mach.h>
34#elif OS(LINUX)
35#include <sys/mman.h>
36#endif
37
38namespace JSC {
39
40alignas(PageSize) JS_EXPORT_PRIVATE Config g_jscConfig;
41
42void Config::disableFreezingForTesting()
43{
44 RELEASE_ASSERT(!g_jscConfig.isPermanentlyFrozen);
45 g_jscConfig.disabledFreezingForTesting = true;
46}
47
48void Config::enableRestrictedOptions()
49{
50 RELEASE_ASSERT(!g_jscConfig.isPermanentlyFrozen);
51 g_jscConfig.restrictedOptionsEnabled = true;
52}
53
54void Config::permanentlyFreeze()
55{
56#if PLATFORM(COCOA)
57 RELEASE_ASSERT(roundUpToMultipleOf(vmPageSize(), ConfigSizeToProtect) == ConfigSizeToProtect);
58#endif
59
60 if (!g_jscConfig.isPermanentlyFrozen)
61 g_jscConfig.isPermanentlyFrozen = true;
62
63 int result = 0;
64#if OS(DARWIN)
65 enum {
66 AllowPermissionChangesAfterThis = false,
67 DisallowPermissionChangesAfterThis = true
68 };
69
70 // There's no going back now!
71 result = vm_protect(mach_task_self(), reinterpret_cast<vm_address_t>(&g_jscConfig), ConfigSizeToProtect, DisallowPermissionChangesAfterThis, VM_PROT_READ);
72#elif OS(LINUX)
73 result = mprotect(&g_jscConfig, ConfigSizeToProtect, PROT_READ);
74#elif OS(WINDOWS)
75 // FIXME: Implement equivalent, maybe with VirtualProtect.
76 // Also need to fix WebKitTestRunner.
77#endif
78 RELEASE_ASSERT(!result);
79 RELEASE_ASSERT(g_jscConfig.isPermanentlyFrozen);
80}
81
82} // namespace JSC
83