jit/ExecutableAllocator.h

   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/PageAllocation.h>
  34 #include <wtf/PassRefPtr.h>
  35 #include <wtf/RefCounted.h>
  36 #include <wtf/UnusedParam.h>
  37 #include <wtf/Vector.h>
  38
  39 #if OS(IOS)
  40 #include <libkern/OSCacheControl.h>
  41 #endif
  42
  43 #if OS(IOS) || OS(QNX)
  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
  61 extern "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
  74 namespace JSC {
  75
  76 class JSGlobalData;
  77 void releaseExecutableMemory(JSGlobalData&);
  78
  79 inline size_t roundUpAllocationSize(size_t request, size_t granularity)
  80 {
  81     if ((std::numeric_limits<size_t>::max() - granularity) <= request)
  82         CRASH(); // Allocation is too large
  83
  84     // Round up to next page boundary
  85     size_t size = request + (granularity - 1);
  86     size = size & ~(granularity - 1);
  87     ASSERT(size >= request);
  88     return size;
  89 }
  90
  91 }
  92
  93 namespace JSC {
  94
  95 typedef WTF::MetaAllocatorHandle ExecutableMemoryHandle;
  96
  97 #if ENABLE(ASSEMBLER)
  98
  99 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
 100 class DemandExecutableAllocator;
 101 #endif
 102
 103 class ExecutableAllocator {
 104     enum ProtectionSetting { Writable, Executable };
 105
 106 public:
 107     ExecutableAllocator(JSGlobalData&);
 108     ~ExecutableAllocator();
 109
 110     static void initializeAllocator();
 111
 112     bool isValid() const;
 113
 114     static bool underMemoryPressure();
 115
 116     static double memoryPressureMultiplier(size_t addedMemoryUsage);
 117
 118 #if ENABLE(META_ALLOCATOR_PROFILE)
 119     static void dumpProfile();
 120 #else
 121     static void dumpProfile() { }
 122 #endif
 123
 124     PassRefPtr<ExecutableMemoryHandle> allocate(JSGlobalData&, size_t sizeInBytes, void* ownerUID, JITCompilationEffort);
 125
 126 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
 127     static void makeWritable(void* start, size_t size)
 128     {
 129         reprotectRegion(start, size, Writable);
 130     }
 131
 132     static void makeExecutable(void* start, size_t size)
 133     {
 134         reprotectRegion(start, size, Executable);
 135     }
 136 #else
 137     static void makeWritable(void*, size_t) {}
 138     static void makeExecutable(void*, size_t) {}
 139 #endif
 140
 141     static size_t committedByteCount();
 142
 143 private:
 144
 145 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
 146     static void reprotectRegion(void*, size_t, ProtectionSetting);
 147 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
 148     // We create a MetaAllocator for each JS global object.
 149     OwnPtr<DemandExecutableAllocator> m_allocator;
 150     DemandExecutableAllocator* allocator() { return m_allocator.get(); }
 151 #endif
 152 #endif
 153
 154 };
 155
 156
 157 #else
 158
 159
 160 class ExecutableAllocator {
 161 public:
 162     static size_t committedByteCount();
 163 };
 164
 165
 166 #endif // ENABLE(JIT) && ENABLE(ASSEMBLER)
 167
 168 } // namespace JSC
 169
 170 #endif // !defined(ExecutableAllocator)