blob: 6cad09001f3514180d4e299af4964454289a430f [file] [log] [blame]
/*
* Copyright (C) 2008-2019 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "ExecutableAllocator.h"
#if ENABLE(JIT)
#include "CodeProfiling.h"
#include "ExecutableAllocationFuzz.h"
#include "JSCInlines.h"
#include <wtf/FileSystem.h>
#include <wtf/MetaAllocator.h>
#include <wtf/PageReservation.h>
#include <wtf/ProcessID.h>
#include <wtf/SystemTracing.h>
#include <wtf/WorkQueue.h>
#if OS(DARWIN)
#include <mach/mach_time.h>
#include <sys/mman.h>
#endif
#if PLATFORM(IOS_FAMILY)
#include <wtf/cocoa/Entitlements.h>
#endif
#include "LinkBuffer.h"
#include "MacroAssembler.h"
#if PLATFORM(COCOA)
#define HAVE_REMAP_JIT 1
#endif
#if HAVE(REMAP_JIT)
#if CPU(ARM64) && PLATFORM(IOS_FAMILY)
#define USE_EXECUTE_ONLY_JIT_WRITE_FUNCTION 1
#endif
#endif
#if OS(DARWIN)
#include <mach/mach.h>
extern "C" {
/* Routine mach_vm_remap */
#ifdef mig_external
mig_external
#else
extern
#endif /* mig_external */
kern_return_t mach_vm_remap
(
vm_map_t target_task,
mach_vm_address_t *target_address,
mach_vm_size_t size,
mach_vm_offset_t mask,
int flags,
vm_map_t src_task,
mach_vm_address_t src_address,
boolean_t copy,
vm_prot_t *cur_protection,
vm_prot_t *max_protection,
vm_inherit_t inheritance
);
}
#endif
namespace JSC {
using namespace WTF;
#if defined(FIXED_EXECUTABLE_MEMORY_POOL_SIZE_IN_MB) && FIXED_EXECUTABLE_MEMORY_POOL_SIZE_IN_MB > 0
static constexpr size_t fixedExecutableMemoryPoolSize = FIXED_EXECUTABLE_MEMORY_POOL_SIZE_IN_MB * 1024 * 1024;
#elif CPU(ARM)
static constexpr size_t fixedExecutableMemoryPoolSize = 16 * 1024 * 1024;
#elif CPU(ARM64)
static constexpr size_t fixedExecutableMemoryPoolSize = 128 * 1024 * 1024;
#elif CPU(X86_64)
static constexpr size_t fixedExecutableMemoryPoolSize = 1024 * 1024 * 1024;
#else
static constexpr size_t fixedExecutableMemoryPoolSize = 32 * 1024 * 1024;
#endif
#if CPU(ARM)
static constexpr double executablePoolReservationFraction = 0.15;
#else
static constexpr double executablePoolReservationFraction = 0.25;
#endif
static bool isJITEnabled()
{
bool jitEnabled = !g_jscConfig.jitDisabled;
#if PLATFORM(IOS_FAMILY) && (CPU(ARM64) || CPU(ARM))
return processHasEntitlement("dynamic-codesigning") && jitEnabled;
#else
return jitEnabled;
#endif
}
void ExecutableAllocator::setJITEnabled(bool enabled)
{
bool jitEnabled = !g_jscConfig.jitDisabled;
ASSERT(!g_jscConfig.fixedVMPoolExecutableAllocator);
if (jitEnabled == enabled)
return;
g_jscConfig.jitDisabled = !enabled;
#if PLATFORM(IOS_FAMILY) && (CPU(ARM64) || CPU(ARM))
if (!enabled) {
// Because of an OS quirk, even after the JIT region has been unmapped,
// the OS thinks that region is reserved, and as such, can cause Gigacage
// allocation to fail. We work around this by initializing the Gigacage
// first.
// Note: when called, setJITEnabled() is always called extra early in the
// process bootstrap. Under normal operation (when setJITEnabled() isn't
// called at all), we will naturally initialize the Gigacage before we
// allocate the JIT region. Hence, this workaround is merely ensuring the
// same behavior of allocation ordering.
Gigacage::ensureGigacage();
constexpr size_t size = 1;
constexpr int protection = PROT_READ | PROT_WRITE | PROT_EXEC;
constexpr int flags = MAP_PRIVATE | MAP_ANON | MAP_JIT;
constexpr int fd = OSAllocator::JSJITCodePages;
void* allocation = mmap(nullptr, size, protection, flags, fd, 0);
const void* executableMemoryAllocationFailure = reinterpret_cast<void*>(-1);
RELEASE_ASSERT_WITH_MESSAGE(allocation && allocation != executableMemoryAllocationFailure, "We should not have allocated executable memory before disabling the JIT.");
RELEASE_ASSERT_WITH_MESSAGE(!munmap(allocation, size), "Unmapping executable memory should succeed so we do not have any executable memory in the address space");
RELEASE_ASSERT_WITH_MESSAGE(mmap(nullptr, size, protection, flags, fd, 0) == executableMemoryAllocationFailure, "Allocating executable memory should fail after setJITEnabled(false) is called.");
}
#endif
}
class FixedVMPoolExecutableAllocator final : public MetaAllocator {
WTF_MAKE_FAST_ALLOCATED;
public:
FixedVMPoolExecutableAllocator()
: MetaAllocator(jitAllocationGranule) // round up all allocations to 32 bytes
{
if (!isJITEnabled())
return;
size_t reservationSize;
if (Options::jitMemoryReservationSize())
reservationSize = Options::jitMemoryReservationSize();
else
reservationSize = fixedExecutableMemoryPoolSize;
reservationSize = std::max(roundUpToMultipleOf(pageSize(), reservationSize), pageSize() * 2);
auto tryCreatePageReservation = [] (size_t reservationSize) {
#if OS(LINUX)
// If we use uncommitted reservation, mmap operation is recorded with small page size in perf command's output.
// This makes the following JIT code logging broken and some of JIT code is not recorded correctly.
// To avoid this problem, we use committed reservation if we need perf JITDump logging.
if (Options::logJITCodeForPerf())
return PageReservation::reserveAndCommitWithGuardPages(reservationSize, OSAllocator::JSJITCodePages, EXECUTABLE_POOL_WRITABLE, true);
#endif
return PageReservation::reserveWithGuardPages(reservationSize, OSAllocator::JSJITCodePages, EXECUTABLE_POOL_WRITABLE, true);
};
m_reservation = tryCreatePageReservation(reservationSize);
if (m_reservation) {
ASSERT(m_reservation.size() == reservationSize);
void* reservationBase = m_reservation.base();
#if ENABLE(FAST_JIT_PERMISSIONS) && !ENABLE(SEPARATED_WX_HEAP)
RELEASE_ASSERT(os_thread_self_restrict_rwx_is_supported());
os_thread_self_restrict_rwx_to_rx();
#else // not ENABLE(FAST_JIT_PERMISSIONS) or ENABLE(SEPARATED_WX_HEAP)
#if ENABLE(FAST_JIT_PERMISSIONS)
if (os_thread_self_restrict_rwx_is_supported()) {
g_jscConfig.useFastPermisionsJITCopy = true;
os_thread_self_restrict_rwx_to_rx();
} else
#endif
if (Options::useSeparatedWXHeap()) {
// First page of our JIT allocation is reserved.
ASSERT(reservationSize >= pageSize() * 2);
reservationBase = (void*)((uintptr_t)reservationBase + pageSize());
reservationSize -= pageSize();
initializeSeparatedWXHeaps(m_reservation.base(), pageSize(), reservationBase, reservationSize);
}
#endif // not ENABLE(FAST_JIT_PERMISSIONS) or ENABLE(SEPARATED_WX_HEAP)
addFreshFreeSpace(reservationBase, reservationSize);
ASSERT(bytesReserved() == reservationSize); // Since our executable memory is fixed-sized, bytesReserved is never changed after initialization.
void* reservationEnd = reinterpret_cast<uint8_t*>(reservationBase) + reservationSize;
g_jscConfig.startExecutableMemory = tagCodePtr<ExecutableMemoryPtrTag>(reservationBase);
g_jscConfig.endExecutableMemory = tagCodePtr<ExecutableMemoryPtrTag>(reservationEnd);
}
}
virtual ~FixedVMPoolExecutableAllocator();
void* memoryStart() { return untagCodePtr<ExecutableMemoryPtrTag>(g_jscConfig.startExecutableMemory); }
void* memoryEnd() { return untagCodePtr<ExecutableMemoryPtrTag>(g_jscConfig.endExecutableMemory); }
bool isJITPC(void* pc) { return memoryStart() <= pc && pc < memoryEnd(); }
protected:
FreeSpacePtr allocateNewSpace(size_t&) override
{
// We're operating in a fixed pool, so new allocation is always prohibited.
return nullptr;
}
void notifyNeedPage(void* page, size_t count) override
{
#if USE(MADV_FREE_FOR_JIT_MEMORY)
UNUSED_PARAM(page);
UNUSED_PARAM(count);
#else
m_reservation.commit(page, pageSize() * count);
#endif
}
void notifyPageIsFree(void* page, size_t count) override
{
#if USE(MADV_FREE_FOR_JIT_MEMORY)
for (;;) {
int result = madvise(page, pageSize() * count, MADV_FREE);
if (!result)
return;
ASSERT(result == -1);
if (errno != EAGAIN) {
RELEASE_ASSERT_NOT_REACHED(); // In debug mode, this should be a hard failure.
break; // In release mode, we should just ignore the error - not returning memory to the OS is better than crashing, especially since we _will_ be able to reuse the memory internally anyway.
}
}
#else
m_reservation.decommit(page, pageSize() * count);
#endif
}
private:
#if OS(DARWIN) && HAVE(REMAP_JIT)
void initializeSeparatedWXHeaps(void* stubBase, size_t stubSize, void* jitBase, size_t jitSize)
{
mach_vm_address_t writableAddr = 0;
// Create a second mapping of the JIT region at a random address.
vm_prot_t cur, max;
int remapFlags = VM_FLAGS_ANYWHERE;
#if defined(VM_FLAGS_RANDOM_ADDR)
remapFlags |= VM_FLAGS_RANDOM_ADDR;
#endif
kern_return_t ret = mach_vm_remap(mach_task_self(), &writableAddr, jitSize, 0,
remapFlags,
mach_task_self(), (mach_vm_address_t)jitBase, FALSE,
&cur, &max, VM_INHERIT_DEFAULT);
bool remapSucceeded = (ret == KERN_SUCCESS);
if (!remapSucceeded)
return;
// Assemble a thunk that will serve as the means for writing into the JIT region.
MacroAssemblerCodeRef<JITThunkPtrTag> writeThunk = jitWriteThunkGenerator(reinterpret_cast<void*>(writableAddr), stubBase, stubSize);
int result = 0;
#if USE(EXECUTE_ONLY_JIT_WRITE_FUNCTION)
// Prevent reading the write thunk code.
result = vm_protect(mach_task_self(), reinterpret_cast<vm_address_t>(stubBase), stubSize, true, VM_PROT_EXECUTE);
RELEASE_ASSERT(!result);
#endif
// Prevent writing into the executable JIT mapping.
result = vm_protect(mach_task_self(), reinterpret_cast<vm_address_t>(jitBase), jitSize, true, VM_PROT_READ | VM_PROT_EXECUTE);
RELEASE_ASSERT(!result);
// Prevent execution in the writable JIT mapping.
result = vm_protect(mach_task_self(), static_cast<vm_address_t>(writableAddr), jitSize, true, VM_PROT_READ | VM_PROT_WRITE);
RELEASE_ASSERT(!result);
// Zero out writableAddr to avoid leaking the address of the writable mapping.
memset_s(&writableAddr, sizeof(writableAddr), 0, sizeof(writableAddr));
#if ENABLE(SEPARATED_WX_HEAP)
g_jscConfig.jitWriteSeparateHeaps = reinterpret_cast<JITWriteSeparateHeapsFunction>(writeThunk.code().executableAddress());
#endif
}
#if CPU(ARM64) && USE(EXECUTE_ONLY_JIT_WRITE_FUNCTION)
MacroAssemblerCodeRef<JITThunkPtrTag> jitWriteThunkGenerator(void* writableAddr, void* stubBase, size_t stubSize)
{
using namespace ARM64Registers;
using TrustedImm32 = MacroAssembler::TrustedImm32;
MacroAssembler jit;
jit.tagReturnAddress();
jit.move(MacroAssembler::TrustedImmPtr(writableAddr), x7);
jit.addPtr(x7, x0);
jit.move(x0, x3);
MacroAssembler::Jump smallCopy = jit.branch64(MacroAssembler::Below, x2, MacroAssembler::TrustedImm64(64));
jit.add64(TrustedImm32(32), x3);
jit.and64(TrustedImm32(-32), x3);
jit.loadPair64(x1, x12, x13);
jit.loadPair64(x1, TrustedImm32(16), x14, x15);
jit.sub64(x3, x0, x5);
jit.addPtr(x5, x1);
jit.loadPair64(x1, x8, x9);
jit.loadPair64(x1, TrustedImm32(16), x10, x11);
jit.add64(TrustedImm32(32), x1);
jit.sub64(x5, x2);
jit.storePair64(x12, x13, x0);
jit.storePair64(x14, x15, x0, TrustedImm32(16));
MacroAssembler::Jump cleanup = jit.branchSub64(MacroAssembler::BelowOrEqual, TrustedImm32(64), x2);
MacroAssembler::Label copyLoop = jit.label();
jit.storePair64WithNonTemporalAccess(x8, x9, x3);
jit.storePair64WithNonTemporalAccess(x10, x11, x3, TrustedImm32(16));
jit.add64(TrustedImm32(32), x3);
jit.loadPair64WithNonTemporalAccess(x1, x8, x9);
jit.loadPair64WithNonTemporalAccess(x1, TrustedImm32(16), x10, x11);
jit.add64(TrustedImm32(32), x1);
jit.branchSub64(MacroAssembler::Above, TrustedImm32(32), x2).linkTo(copyLoop, &jit);
cleanup.link(&jit);
jit.add64(x2, x1);
jit.loadPair64(x1, x12, x13);
jit.loadPair64(x1, TrustedImm32(16), x14, x15);
jit.storePair64(x8, x9, x3);
jit.storePair64(x10, x11, x3, TrustedImm32(16));
jit.addPtr(x2, x3);
jit.storePair64(x12, x13, x3, TrustedImm32(32));
jit.storePair64(x14, x15, x3, TrustedImm32(48));
jit.ret();
MacroAssembler::Label local0 = jit.label();
jit.load64(x1, PostIndex(8), x6);
jit.store64(x6, x3, PostIndex(8));
smallCopy.link(&jit);
jit.branchSub64(MacroAssembler::AboveOrEqual, TrustedImm32(8), x2).linkTo(local0, &jit);
MacroAssembler::Jump local2 = jit.branchAdd64(MacroAssembler::Equal, TrustedImm32(8), x2);
MacroAssembler::Label local1 = jit.label();
jit.load8(x1, PostIndex(1), x6);
jit.store8(x6, x3, PostIndex(1));
jit.branchSub64(MacroAssembler::NotEqual, TrustedImm32(1), x2).linkTo(local1, &jit);
local2.link(&jit);
jit.ret();
auto stubBaseCodePtr = MacroAssemblerCodePtr<LinkBufferPtrTag>(tagCodePtr<LinkBufferPtrTag>(stubBase));
LinkBuffer linkBuffer(jit, stubBaseCodePtr, stubSize);
// We don't use FINALIZE_CODE() for two reasons.
// The first is that we don't want the writeable address, as disassembled instructions,
// to appear in the console or anywhere in memory, via the PrintStream buffer.
// The second is we can't guarantee that the code is readable when using the
// asyncDisassembly option as our caller will set our pages execute only.
return linkBuffer.finalizeCodeWithoutDisassembly<JITThunkPtrTag>();
}
#else // not CPU(ARM64) && USE(EXECUTE_ONLY_JIT_WRITE_FUNCTION)
static void genericWriteToJITRegion(off_t offset, const void* data, size_t dataSize)
{
memcpy((void*)(g_jscConfig.startOfFixedWritableMemoryPool + offset), data, dataSize);
}
MacroAssemblerCodeRef<JITThunkPtrTag> jitWriteThunkGenerator(void* address, void*, size_t)
{
g_jscConfig.startOfFixedWritableMemoryPool = reinterpret_cast<uintptr_t>(address);
void* function = reinterpret_cast<void*>(&genericWriteToJITRegion);
#if CPU(ARM_THUMB2)
// Handle thumb offset
uintptr_t functionAsInt = reinterpret_cast<uintptr_t>(function);
functionAsInt -= 1;
function = reinterpret_cast<void*>(functionAsInt);
#endif
auto codePtr = MacroAssemblerCodePtr<JITThunkPtrTag>(tagCFunctionPtr<JITThunkPtrTag>(function));
return MacroAssemblerCodeRef<JITThunkPtrTag>::createSelfManagedCodeRef(codePtr);
}
#endif // CPU(ARM64) && USE(EXECUTE_ONLY_JIT_WRITE_FUNCTION)
#else // OS(DARWIN) && HAVE(REMAP_JIT)
void initializeSeparatedWXHeaps(void*, size_t, void*, size_t)
{
}
#endif
private:
PageReservation m_reservation;
};
FixedVMPoolExecutableAllocator::~FixedVMPoolExecutableAllocator()
{
m_reservation.deallocate();
}
// Keep this pointer in a mutable global variable to help Leaks find it.
// But we do not use this pointer.
static FixedVMPoolExecutableAllocator* globalFixedVMPoolExecutableAllocatorToWorkAroundLeaks = nullptr;
void ExecutableAllocator::initializeUnderlyingAllocator()
{
RELEASE_ASSERT(!g_jscConfig.fixedVMPoolExecutableAllocator);
g_jscConfig.fixedVMPoolExecutableAllocator = new FixedVMPoolExecutableAllocator();
globalFixedVMPoolExecutableAllocatorToWorkAroundLeaks = g_jscConfig.fixedVMPoolExecutableAllocator;
CodeProfiling::notifyAllocator(g_jscConfig.fixedVMPoolExecutableAllocator);
}
bool ExecutableAllocator::isValid() const
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return Base::isValid();
return !!allocator->bytesReserved();
}
bool ExecutableAllocator::underMemoryPressure()
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return Base::underMemoryPressure();
return allocator->bytesAllocated() > allocator->bytesReserved() / 2;
}
double ExecutableAllocator::memoryPressureMultiplier(size_t addedMemoryUsage)
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return Base::memoryPressureMultiplier(addedMemoryUsage);
ASSERT(allocator->bytesAllocated() <= allocator->bytesReserved());
size_t bytesAllocated = allocator->bytesAllocated() + addedMemoryUsage;
size_t bytesAvailable = static_cast<size_t>(
allocator->bytesReserved() * (1 - executablePoolReservationFraction));
if (bytesAllocated >= bytesAvailable)
bytesAllocated = bytesAvailable;
double result = 1.0;
size_t divisor = bytesAvailable - bytesAllocated;
if (divisor)
result = static_cast<double>(bytesAvailable) / divisor;
if (result < 1.0)
result = 1.0;
return result;
}
RefPtr<ExecutableMemoryHandle> ExecutableAllocator::allocate(size_t sizeInBytes, void* ownerUID, JITCompilationEffort effort)
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return Base::allocate(sizeInBytes, ownerUID, effort);
if (Options::logExecutableAllocation()) {
MetaAllocator::Statistics stats = allocator->currentStatistics();
dataLog("Allocating ", sizeInBytes, " bytes of executable memory with ", stats.bytesAllocated, " bytes allocated, ", stats.bytesReserved, " bytes reserved, and ", stats.bytesCommitted, " committed.\n");
}
if (effort != JITCompilationCanFail && Options::reportMustSucceedExecutableAllocations()) {
dataLog("Allocating ", sizeInBytes, " bytes of executable memory with JITCompilationMustSucceed.\n");
WTFReportBacktrace();
}
if (effort == JITCompilationCanFail
&& doExecutableAllocationFuzzingIfEnabled() == PretendToFailExecutableAllocation)
return nullptr;
if (effort == JITCompilationCanFail) {
// Don't allow allocations if we are down to reserve.
size_t bytesAllocated = allocator->bytesAllocated() + sizeInBytes;
size_t bytesAvailable = static_cast<size_t>(
allocator->bytesReserved() * (1 - executablePoolReservationFraction));
if (bytesAllocated > bytesAvailable) {
if (Options::logExecutableAllocation())
dataLog("Allocation failed because bytes allocated ", bytesAllocated, " > ", bytesAvailable, " bytes available.\n");
return nullptr;
}
}
RefPtr<ExecutableMemoryHandle> result = allocator->allocate(sizeInBytes, ownerUID);
if (!result) {
if (effort != JITCompilationCanFail) {
dataLog("Ran out of executable memory while allocating ", sizeInBytes, " bytes.\n");
CRASH();
}
return nullptr;
}
void* start = allocator->memoryStart();
void* end = allocator->memoryEnd();
void* resultStart = result->start().untaggedPtr();
void* resultEnd = result->end().untaggedPtr();
RELEASE_ASSERT(start <= resultStart && resultStart < end);
RELEASE_ASSERT(start < resultEnd && resultEnd <= end);
return result;
}
bool ExecutableAllocator::isValidExecutableMemory(const AbstractLocker& locker, void* address)
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return Base::isValidExecutableMemory(locker, address);
return allocator->isInAllocatedMemory(locker, address);
}
Lock& ExecutableAllocator::getLock() const
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return Base::getLock();
return allocator->getLock();
}
size_t ExecutableAllocator::committedByteCount()
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return Base::committedByteCount();
return allocator->bytesCommitted();
}
#if ENABLE(META_ALLOCATOR_PROFILE)
void ExecutableAllocator::dumpProfile()
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return;
allocator->dumpProfile();
}
#endif
void* startOfFixedExecutableMemoryPoolImpl()
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return nullptr;
return allocator->memoryStart();
}
void* endOfFixedExecutableMemoryPoolImpl()
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
if (!allocator)
return nullptr;
return allocator->memoryEnd();
}
bool isJITPC(void* pc)
{
auto* allocator = g_jscConfig.fixedVMPoolExecutableAllocator;
return allocator && allocator->isJITPC(pc);
}
void dumpJITMemory(const void* dst, const void* src, size_t size)
{
RELEASE_ASSERT(Options::dumpJITMemoryPath());
#if OS(DARWIN)
static int fd = -1;
static uint8_t* buffer;
static constexpr size_t bufferSize = fixedExecutableMemoryPoolSize;
static size_t offset = 0;
static Lock dumpJITMemoryLock;
static bool needsToFlush = false;
static auto flush = [](const AbstractLocker&) {
if (fd == -1) {
String path = Options::dumpJITMemoryPath();
path = path.replace("%pid", String::number(getCurrentProcessID()));
fd = open(FileSystem::fileSystemRepresentation(path).data(), O_CREAT | O_TRUNC | O_APPEND | O_WRONLY | O_EXLOCK | O_NONBLOCK, 0666);
RELEASE_ASSERT(fd != -1);
}
write(fd, buffer, offset);
offset = 0;
needsToFlush = false;
};
static std::once_flag once;
static LazyNeverDestroyed<Ref<WorkQueue>> flushQueue;
std::call_once(once, [] {
buffer = bitwise_cast<uint8_t*>(malloc(bufferSize));
flushQueue.construct(WorkQueue::create("jsc.dumpJITMemory.queue", WorkQueue::Type::Serial, WorkQueue::QOS::Background));
std::atexit([] {
LockHolder locker(dumpJITMemoryLock);
flush(locker);
close(fd);
fd = -1;
});
});
static auto enqueueFlush = [](const AbstractLocker&) {
if (needsToFlush)
return;
needsToFlush = true;
flushQueue.get()->dispatchAfter(Seconds(Options::dumpJITMemoryFlushInterval()), [] {
LockHolder locker(dumpJITMemoryLock);
if (!needsToFlush)
return;
flush(locker);
});
};
static auto write = [](const AbstractLocker& locker, const void* src, size_t size) {
if (UNLIKELY(offset + size > bufferSize))
flush(locker);
memcpy(buffer + offset, src, size);
offset += size;
enqueueFlush(locker);
};
LockHolder locker(dumpJITMemoryLock);
uint64_t time = mach_absolute_time();
uint64_t dst64 = bitwise_cast<uintptr_t>(dst);
uint64_t size64 = size;
TraceScope(DumpJITMemoryStart, DumpJITMemoryStop, time, dst64, size64);
write(locker, &time, sizeof(time));
write(locker, &dst64, sizeof(dst64));
write(locker, &size64, sizeof(size64));
write(locker, src, size);
#else
UNUSED_PARAM(dst);
UNUSED_PARAM(src);
UNUSED_PARAM(size);
RELEASE_ASSERT_NOT_REACHED();
#endif
}
} // namespace JSC
#endif // ENABLE(JIT)
namespace JSC {
// Keep this pointer in a mutable global variable to help Leaks find it.
// But we do not use this pointer.
static ExecutableAllocator* globalExecutableAllocatorToWorkAroundLeaks = nullptr;
void ExecutableAllocator::initialize()
{
g_jscConfig.executableAllocator = new ExecutableAllocator;
globalExecutableAllocatorToWorkAroundLeaks = g_jscConfig.executableAllocator;
}
ExecutableAllocator& ExecutableAllocator::singleton()
{
ASSERT(g_jscConfig.executableAllocator);
return *g_jscConfig.executableAllocator;
}
} // namespace JSC