interpreter/JSStack.cpp

   1 /*
   2  * Copyright (C) 2008, 2013, 2014 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  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "config.h"
  30 #include "JSStackInlines.h"
  31
  32 #include "ConservativeRoots.h"
  33 #include "Interpreter.h"
  34 #include "JSCInlines.h"
  35 #include "Options.h"
  36
  37 namespace JSC {
  38
  39 #if !ENABLE(JIT)
  40 static size_t committedBytesCount = 0;
  41
  42 static Mutex& stackStatisticsMutex()
  43 {
  44     DEPRECATED_DEFINE_STATIC_LOCAL(Mutex, staticMutex, ());
  45     return staticMutex;
  46 }
  47 #endif // !ENABLE(JIT)
  48
  49 JSStack::JSStack(VM& vm)
  50     : m_vm(vm)
  51     , m_topCallFrame(vm.topCallFrame)
  52 #if !ENABLE(JIT)
  53     , m_end(0)
  54     , m_reservedZoneSizeInRegisters(0)
  55 #endif
  56 {
  57 #if !ENABLE(JIT)
  58     size_t capacity = Options::maxPerThreadStackUsage();
  59     ASSERT(capacity && isPageAligned(capacity));
  60
  61     m_reservation = PageReservation::reserve(WTF::roundUpToMultipleOf(commitSize, capacity), OSAllocator::JSVMStackPages);
  62     setStackLimit(highAddress());
  63     m_commitTop = highAddress();
  64
  65     m_lastStackTop = baseOfStack();
  66 #endif // !ENABLE(JIT)
  67
  68     m_topCallFrame = 0;
  69 }
  70
  71 #if !ENABLE(JIT)
  72 JSStack::~JSStack()
  73 {
  74     ptrdiff_t sizeToDecommit = reinterpret_cast<char*>(highAddress()) - reinterpret_cast<char*>(m_commitTop);
  75     m_reservation.decommit(reinterpret_cast<void*>(m_commitTop), sizeToDecommit);
  76     addToCommittedByteCount(-sizeToDecommit);
  77     m_reservation.deallocate();
  78 }
  79
  80 bool JSStack::growSlowCase(Register* newTopOfStack)
  81 {
  82     Register* newTopOfStackWithReservedZone = newTopOfStack - m_reservedZoneSizeInRegisters;
  83
  84     // If we have already committed enough memory to satisfy this request,
  85     // just update the end pointer and return.
  86     if (newTopOfStackWithReservedZone >= m_commitTop) {
  87         setStackLimit(newTopOfStack);
  88         return true;
  89     }
  90
  91     // Compute the chunk size of additional memory to commit, and see if we
  92     // have it is still within our budget. If not, we'll fail to grow and
  93     // return false.
  94     ptrdiff_t delta = reinterpret_cast<char*>(m_commitTop) - reinterpret_cast<char*>(newTopOfStackWithReservedZone);
  95     delta = WTF::roundUpToMultipleOf(commitSize, delta);
  96     Register* newCommitTop = m_commitTop - (delta / sizeof(Register));
  97     if (newCommitTop < reservationTop())
  98         return false;
  99
 100     // Otherwise, the growth is still within our budget. Go ahead and commit
 101     // it and return true.
 102     m_reservation.commit(newCommitTop, delta);
 103     addToCommittedByteCount(delta);
 104     m_commitTop = newCommitTop;
 105     setStackLimit(newTopOfStack);
 106     return true;
 107 }
 108
 109 void JSStack::gatherConservativeRoots(ConservativeRoots& conservativeRoots)
 110 {
 111     conservativeRoots.add(topOfStack() + 1, highAddress());
 112 }
 113
 114 void JSStack::gatherConservativeRoots(ConservativeRoots& conservativeRoots, JITStubRoutineSet& jitStubRoutines, CodeBlockSet& codeBlocks)
 115 {
 116     conservativeRoots.add(topOfStack() + 1, highAddress(), jitStubRoutines, codeBlocks);
 117 }
 118
 119 void JSStack::sanitizeStack()
 120 {
 121 #if !defined(ADDRESS_SANITIZER)
 122     ASSERT(topOfStack() <= baseOfStack());
 123
 124     if (m_lastStackTop < topOfStack()) {
 125         char* begin = reinterpret_cast<char*>(m_lastStackTop + 1);
 126         char* end = reinterpret_cast<char*>(topOfStack() + 1);
 127         memset(begin, 0, end - begin);
 128     }
 129
 130     m_lastStackTop = topOfStack();
 131 #endif
 132 }
 133
 134 void JSStack::releaseExcessCapacity()
 135 {
 136     Register* highAddressWithReservedZone = highAddress() - m_reservedZoneSizeInRegisters;
 137     ptrdiff_t delta = reinterpret_cast<char*>(highAddressWithReservedZone) - reinterpret_cast<char*>(m_commitTop);
 138     m_reservation.decommit(m_commitTop, delta);
 139     addToCommittedByteCount(-delta);
 140     m_commitTop = highAddressWithReservedZone;
 141 }
 142
 143 void JSStack::initializeThreading()
 144 {
 145     stackStatisticsMutex();
 146 }
 147
 148 void JSStack::addToCommittedByteCount(long byteCount)
 149 {
 150     MutexLocker locker(stackStatisticsMutex());
 151     ASSERT(static_cast<long>(committedBytesCount) + byteCount > -1);
 152     committedBytesCount += byteCount;
 153 }
 154
 155 void JSStack::setReservedZoneSize(size_t reservedZoneSize)
 156 {
 157     m_reservedZoneSizeInRegisters = reservedZoneSize / sizeof(Register);
 158     if (m_commitTop >= (m_end + 1) - m_reservedZoneSizeInRegisters)
 159         growSlowCase(m_end + 1);
 160 }
 161 #endif // !ENABLE(JIT)
 162
 163 #if ENABLE(JIT)
 164 Register* JSStack::lowAddress() const
 165 {
 166     ASSERT(wtfThreadData().stack().isGrowingDownward());
 167     return reinterpret_cast<Register*>(m_vm.stackLimit());
 168 }
 169
 170 Register* JSStack::highAddress() const
 171 {
 172     ASSERT(wtfThreadData().stack().isGrowingDownward());
 173     return reinterpret_cast<Register*>(wtfThreadData().stack().origin());
 174 }
 175 #endif // ENABLE(JIT)
 176
 177 size_t JSStack::committedByteCount()
 178 {
 179 #if !ENABLE(JIT)
 180     MutexLocker locker(stackStatisticsMutex());
 181     return committedBytesCount;
 182 #else
 183     // When using the C stack, we don't know how many stack pages are actually
 184     // committed. So, we use the current stack usage as an estimate.
 185     ASSERT(wtfThreadData().stack().isGrowingDownward());
 186     int8_t* current = reinterpret_cast<int8_t*>(&current);
 187     int8_t* high = reinterpret_cast<int8_t*>(wtfThreadData().stack().origin());
 188     return high - current;
 189 #endif
 190 }
 191
 192 } // namespace JSC