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#ifndef ExecutableAllocator_h
27#define ExecutableAllocator_h
28#include "JITCompilationEffort.h"
29#include <stddef.h> // for ptrdiff_t
30#include <limits>
31#include <wtf/Assertions.h>
32#include <wtf/MetaAllocatorHandle.h>
33#include <wtf/MetaAllocator.h>
34#include <wtf/PageAllocation.h>
35#include <wtf/PassRefPtr.h>
36#include <wtf/RefCounted.h>
37#include <wtf/Vector.h>
38
39#if OS(IOS)
40#include <libkern/OSCacheControl.h>
41#endif
42
43#if OS(IOS)
44#include <sys/mman.h>
45#endif
46
47#if CPU(MIPS) && OS(LINUX)
48#include <sys/cachectl.h>
49#endif
50
51#if CPU(SH4) && OS(LINUX)
52#include <asm/cachectl.h>
53#include <asm/unistd.h>
54#include <sys/syscall.h>
55#include <unistd.h>
56#endif
57
58#if OS(WINCE)
59// From pkfuncs.h (private header file from the Platform Builder)
60#define CACHE_SYNC_ALL 0x07F
61extern "C" __declspec(dllimport) void CacheRangeFlush(LPVOID pAddr, DWORD dwLength, DWORD dwFlags);
62#endif
63
64#define JIT_ALLOCATOR_LARGE_ALLOC_SIZE (pageSize() * 4)
65
66#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
67#define PROTECTION_FLAGS_RW (PROT_READ | PROT_WRITE)
68#define PROTECTION_FLAGS_RX (PROT_READ | PROT_EXEC)
69#define EXECUTABLE_POOL_WRITABLE false
70#else
71#define EXECUTABLE_POOL_WRITABLE true
72#endif
73
74namespace JSC {
75
76class VM;
77void releaseExecutableMemory(VM&);
78
79static const unsigned jitAllocationGranule = 32;
80
81typedef WTF::MetaAllocatorHandle ExecutableMemoryHandle;
82
83#if ENABLE(ASSEMBLER)
84
85#if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
86class DemandExecutableAllocator;
87#endif
88
89#if ENABLE(EXECUTABLE_ALLOCATOR_FIXED)
90#if CPU(ARM) || CPU(ARM64)
91static const size_t fixedExecutableMemoryPoolSize = 16 * 1024 * 1024;
92#elif CPU(X86_64)
93static const size_t fixedExecutableMemoryPoolSize = 1024 * 1024 * 1024;
94#else
95static const size_t fixedExecutableMemoryPoolSize = 32 * 1024 * 1024;
96#endif
97
98extern uintptr_t startOfFixedExecutableMemoryPool;
99#endif
100
101class ExecutableAllocator {
102    enum ProtectionSetting { Writable, Executable };
103
104public:
105    ExecutableAllocator(VM&);
106    ~ExecutableAllocator();
107
108    static void initializeAllocator();
109
110    bool isValid() const;
111
112    static bool underMemoryPressure();
113
114    static double memoryPressureMultiplier(size_t addedMemoryUsage);
115
116#if ENABLE(META_ALLOCATOR_PROFILE)
117    static void dumpProfile();
118#else
119    static void dumpProfile() { }
120#endif
121
122    PassRefPtr<ExecutableMemoryHandle> allocate(VM&, size_t sizeInBytes, void* ownerUID, JITCompilationEffort);
123
124#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
125    static void makeWritable(void* start, size_t size)
126    {
127        reprotectRegion(start, size, Writable);
128    }
129
130    static void makeExecutable(void* start, size_t size)
131    {
132        reprotectRegion(start, size, Executable);
133    }
134#else
135    static void makeWritable(void*, size_t) {}
136    static void makeExecutable(void*, size_t) {}
137#endif
138
139    static size_t committedByteCount();
140
141private:
142
143#if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
144    static void reprotectRegion(void*, size_t, ProtectionSetting);
145#if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
146    // We create a MetaAllocator for each JS global object.
147    OwnPtr<DemandExecutableAllocator> m_allocator;
148    DemandExecutableAllocator* allocator() { return m_allocator.get(); }
149#endif
150#endif
151
152};
153
154#endif // ENABLE(JIT) && ENABLE(ASSEMBLER)
155
156} // namespace JSC
157
158#endif // !defined(ExecutableAllocator)
159