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/MetaAllocator.h>
  34 #include <wtf/PageAllocation.h>
  35 #include <wtf/RefCounted.h>
  36 #include <wtf/Vector.h>
  37
  38 #if OS(IOS)
  39 #include <libkern/OSCacheControl.h>
  40 #endif
  41
  42 #if OS(IOS)
  43 #include <sys/mman.h>
  44 #endif
  45
  46 #if CPU(MIPS) && OS(LINUX)
  47 #include <sys/cachectl.h>
  48 #endif
  49
  50 #if CPU(SH4) && OS(LINUX)
  51 #include <asm/cachectl.h>
  52 #include <asm/unistd.h>
  53 #include <sys/syscall.h>
  54 #include <unistd.h>
  55 #endif
  56
  57 #define JIT_ALLOCATOR_LARGE_ALLOC_SIZE (pageSize() * 4)
  58
  59 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
  60 #define PROTECTION_FLAGS_RW (PROT_READ | PROT_WRITE)
  61 #define PROTECTION_FLAGS_RX (PROT_READ | PROT_EXEC)
  62 #define EXECUTABLE_POOL_WRITABLE false
  63 #else
  64 #define EXECUTABLE_POOL_WRITABLE true
  65 #endif
  66
  67 namespace JSC {
  68
  69 class VM;
  70 void releaseExecutableMemory(VM&);
  71
  72 static const unsigned jitAllocationGranule = 32;
  73
  74 typedef WTF::MetaAllocatorHandle ExecutableMemoryHandle;
  75
  76 #if ENABLE(ASSEMBLER)
  77
  78 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
  79 class DemandExecutableAllocator;
  80 #endif
  81
  82 #if ENABLE(EXECUTABLE_ALLOCATOR_FIXED)
  83 #if CPU(ARM)
  84 static const size_t fixedExecutableMemoryPoolSize = 16 * 1024 * 1024;
  85 #elif CPU(ARM64)
  86 static const size_t fixedExecutableMemoryPoolSize = 32 * 1024 * 1024;
  87 #elif CPU(X86_64)
  88 static const size_t fixedExecutableMemoryPoolSize = 1024 * 1024 * 1024;
  89 #else
  90 static const size_t fixedExecutableMemoryPoolSize = 32 * 1024 * 1024;
  91 #endif
  92 static const double executablePoolReservationFraction = 0.25;
  93
  94 extern uintptr_t startOfFixedExecutableMemoryPool;
  95 #endif
  96
  97 class ExecutableAllocator {
  98     enum ProtectionSetting { Writable, Executable };
  99
 100 public:
 101     ExecutableAllocator(VM&);
 102     ~ExecutableAllocator();
 103
 104     static void initializeAllocator();
 105
 106     bool isValid() const;
 107
 108     static bool underMemoryPressure();
 109
 110     static double memoryPressureMultiplier(size_t addedMemoryUsage);
 111
 112 #if ENABLE(META_ALLOCATOR_PROFILE)
 113     static void dumpProfile();
 114 #else
 115     static void dumpProfile() { }
 116 #endif
 117
 118     RefPtr<ExecutableMemoryHandle> allocate(VM&, size_t sizeInBytes, void* ownerUID, JITCompilationEffort);
 119
 120 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
 121     static void makeWritable(void* start, size_t size)
 122     {
 123         reprotectRegion(start, size, Writable);
 124     }
 125
 126     static void makeExecutable(void* start, size_t size)
 127     {
 128         reprotectRegion(start, size, Executable);
 129     }
 130 #else
 131     static void makeWritable(void*, size_t) {}
 132     static void makeExecutable(void*, size_t) {}
 133 #endif
 134
 135     static size_t committedByteCount();
 136
 137 private:
 138
 139 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE)
 140     static void reprotectRegion(void*, size_t, ProtectionSetting);
 141 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND)
 142     // We create a MetaAllocator for each JS global object.
 143     std::unique_ptr<DemandExecutableAllocator> m_allocator;
 144     DemandExecutableAllocator* allocator() { return m_allocator.get(); }
 145 #endif
 146 #endif
 147
 148 };
 149
 150 #endif // ENABLE(JIT) && ENABLE(ASSEMBLER)
 151
 152 } // namespace JSC
 153
 154 #endif // !defined(ExecutableAllocator)