bool QSharedMemoryPrivate::attach(QSharedMemory::AccessMode mode)
{
const QByteArray shmName = QFile::encodeName(makePlatformSafeKey(key));
const int oflag = (mode == QSharedMemory::ReadOnly ? O_RDONLY : O_RDWR);
const mode_t omode = (mode == QSharedMemory::ReadOnly ? 0400 : 0600);
#ifdef O_CLOEXEC
// First try with O_CLOEXEC flag, if that fails, fall back to normal flags
EINTR_LOOP(hand, ::shm_open(shmName.constData(), oflag | O_CLOEXEC, omode));
if (hand == -1)
EINTR_LOOP(hand, ::shm_open(shmName.constData(), oflag, omode));
#else
EINTR_LOOP(hand, ::shm_open(shmName.constData(), oflag, omode));
#endif
if (hand == -1) {
const int errorNumber = errno;
const QLatin1String function("QSharedMemory::attach (shm_open)");
switch (errorNumber) {
case ENAMETOOLONG:
case EINVAL:
errorString = QSharedMemory::tr("%1: bad name").arg(function);
error = QSharedMemory::KeyError;
break;
default:
setErrorString(function);
}
hand = -1;
return false;
}
// grab the size
QT_STATBUF st;
if (QT_FSTAT(hand, &st) == -1) {
setErrorString(QLatin1String("QSharedMemory::attach (fstat)"));
cleanHandle();
return false;
}
size = st.st_size;
// grab the memory
const int mprot = (mode == QSharedMemory::ReadOnly ? PROT_READ : PROT_READ | PROT_WRITE);
memory = QT_MMAP(0, size, mprot, MAP_SHARED, hand, 0);
if (memory == MAP_FAILED || !memory) {
setErrorString(QLatin1String("QSharedMemory::attach (mmap)"));
cleanHandle();
memory = 0;
size = 0;
return false;
}
#ifdef F_ADD_SEALS
// Make sure the shared memory region will not shrink
// otherwise someone could cause SIGBUS on us.
// (see http://lwn.net/Articles/594919/)
fcntl(hand, F_ADD_SEALS, F_SEAL_SHRINK);
#endif
return true;
}
uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size, QFile::MemoryMapFlags flags)
{
Q_Q(QFSFileEngine);
Q_UNUSED(flags);
if (openMode == QIODevice::NotOpen) {
q->setError(QFile::PermissionsError, qt_error_string(int(EACCES)));
return 0;
}
if (offset < 0 || offset != qint64(QT_OFF_T(offset))
|| size < 0 || quint64(size) > quint64(size_t(-1))) {
q->setError(QFile::UnspecifiedError, qt_error_string(int(EINVAL)));
return 0;
}
// If we know the mapping will extend beyond EOF, fail early to avoid
// undefined behavior. Otherwise, let mmap have its say.
if (doStat(QFileSystemMetaData::SizeAttribute)
&& (QT_OFF_T(size) > metaData.size() - QT_OFF_T(offset)))
qWarning("QFSFileEngine::map: Mapping a file beyond its size is not portable");
int access = 0;
if (openMode & QIODevice::ReadOnly) access |= PROT_READ;
if (openMode & QIODevice::WriteOnly) access |= PROT_WRITE;
#if defined(Q_OS_INTEGRITY)
int pageSize = sysconf(_SC_PAGESIZE);
#else
int pageSize = getpagesize();
#endif
int extra = offset % pageSize;
if (quint64(size + extra) > quint64((size_t)-1)) {
q->setError(QFile::UnspecifiedError, qt_error_string(int(EINVAL)));
return 0;
}
size_t realSize = (size_t)size + extra;
QT_OFF_T realOffset = QT_OFF_T(offset);
realOffset &= ~(QT_OFF_T(pageSize - 1));
#ifdef QT_SYMBIAN_USE_NATIVE_FILEMAP
TInt nativeMapError = KErrNone;
RFileMap mapping;
TUint mode(EFileMapRemovableMedia);
TUint64 nativeOffset = offset & ~(mapping.PageSizeInBytes() - 1);
//If the file was opened for write or read/write, then open the map for read/write
if (openMode & QIODevice::WriteOnly)
mode |= EFileMapWrite;
if (symbianFile.SubSessionHandle()) {
nativeMapError = mapping.Open(symbianFile, nativeOffset, size, mode);
} else {
//map file by name if we don't have a native handle
QString fn = QFileSystemEngine::absoluteName(fileEntry).nativeFilePath();
TUint filemode = EFileShareReadersOrWriters | EFileRead;
if (openMode & QIODevice::WriteOnly)
filemode |= EFileWrite;
nativeMapError = mapping.Open(qt_s60GetRFs(), qt_QString2TPtrC(fn), filemode, nativeOffset, size, mode);
}
if (nativeMapError == KErrNone) {
QScopedResource<RFileMap> ptr(mapping); //will call Close if adding to mapping throws an exception
uchar *address = mapping.Base() + (offset - nativeOffset);
maps[address] = mapping;
ptr.take();
return address;
}
QFile::FileError reportedError = QFile::UnspecifiedError;
switch (nativeMapError) {
case KErrAccessDenied:
case KErrPermissionDenied:
reportedError = QFile::PermissionsError;
break;
case KErrNoMemory:
reportedError = QFile::ResourceError;
break;
}
q->setError(reportedError, QSystemError(nativeMapError, QSystemError::NativeError).toString());
return 0;
#else
#ifdef Q_OS_SYMBIAN
//older phones & emulator don't support native mapping, so need to keep the open C way around for those.
void *mapAddress;
TRAPD(err, mapAddress = QT_MMAP((void*)0, realSize,
access, MAP_SHARED, getMapHandle(), realOffset));
if (err != KErrNone) {
qWarning("OpenC bug: leave from mmap %d", err);
mapAddress = MAP_FAILED;
errno = EINVAL;
}
#else
void *mapAddress = QT_MMAP((void*)0, realSize,
access, MAP_SHARED, nativeHandle(), realOffset);
#endif
if (MAP_FAILED != mapAddress) {
uchar *address = extra + static_cast<uchar*>(mapAddress);
maps[address] = QPair<int,size_t>(extra, realSize);
return address;
}
switch(errno) {
case EBADF:
q->setError(QFile::PermissionsError, qt_error_string(int(EACCES)));
break;
case ENFILE:
case ENOMEM:
q->setError(QFile::ResourceError, qt_error_string(int(errno)));
break;
case EINVAL:
// size are out of bounds
default:
q->setError(QFile::UnspecifiedError, qt_error_string(int(errno)));
break;
}
return 0;
#endif
}
uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size, QFile::MemoryMapFlags flags)
{
Q_Q(QFSFileEngine);
Q_UNUSED(flags);
if (openMode == QIODevice::NotOpen) {
q->setError(QFile::PermissionsError, qt_error_string(int(EACCES)));
return 0;
}
if (offset < 0 || offset != qint64(QT_OFF_T(offset))
|| size < 0 || quint64(size) > quint64(size_t(-1))) {
q->setError(QFile::UnspecifiedError, qt_error_string(int(EINVAL)));
return 0;
}
// If we know the mapping will extend beyond EOF, fail early to avoid
// undefined behavior. Otherwise, let mmap have its say.
if (doStat(QFileSystemMetaData::SizeAttribute)
&& (QT_OFF_T(size) > metaData.size() - QT_OFF_T(offset)))
qWarning("QFSFileEngine::map: Mapping a file beyond its size is not portable");
int access = 0;
if (openMode & QIODevice::ReadOnly) access |= PROT_READ;
if (openMode & QIODevice::WriteOnly) access |= PROT_WRITE;
int sharemode = MAP_SHARED;
if (flags & QFileDevice::MapPrivateOption) {
sharemode = MAP_PRIVATE;
access |= PROT_WRITE;
}
#if defined(Q_OS_INTEGRITY)
int pageSize = sysconf(_SC_PAGESIZE);
#else
int pageSize = getpagesize();
#endif
int extra = offset % pageSize;
if (quint64(size + extra) > quint64((size_t)-1)) {
q->setError(QFile::UnspecifiedError, qt_error_string(int(EINVAL)));
return 0;
}
size_t realSize = (size_t)size + extra;
QT_OFF_T realOffset = QT_OFF_T(offset);
realOffset &= ~(QT_OFF_T(pageSize - 1));
void *mapAddress = QT_MMAP((void*)0, realSize,
access, sharemode, nativeHandle(), realOffset);
if (MAP_FAILED != mapAddress) {
uchar *address = extra + static_cast<uchar*>(mapAddress);
maps[address] = QPair<int,size_t>(extra, realSize);
return address;
}
switch(errno) {
case EBADF:
q->setError(QFile::PermissionsError, qt_error_string(int(EACCES)));
break;
case ENFILE:
case ENOMEM:
q->setError(QFile::ResourceError, qt_error_string(int(errno)));
break;
case EINVAL:
// size are out of bounds
default:
q->setError(QFile::UnspecifiedError, qt_error_string(int(errno)));
break;
}
return 0;
}
