diff options
Diffstat (limited to 'src/corelib/io/qfsfileengine_unix.cpp')
| -rw-r--r-- | src/corelib/io/qfsfileengine_unix.cpp | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/src/corelib/io/qfsfileengine_unix.cpp b/src/corelib/io/qfsfileengine_unix.cpp index ff77278dc1..4be4e893b3 100644 --- a/src/corelib/io/qfsfileengine_unix.cpp +++ b/src/corelib/io/qfsfileengine_unix.cpp @@ -688,6 +688,19 @@ QDateTime QFSFileEngine::fileTime(FileTime time) const uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size, QFile::MemoryMapFlags flags) { +#if (defined(Q_OS_LINUX) || defined(Q_OS_ANDROID)) && Q_PROCESSOR_WORDSIZE == 4 + // The Linux mmap2 system call on 32-bit takes a page-shifted 32-bit + // integer so the maximum offset is 1 << (32+12) (the shift is always 12, + // regardless of the actual page size). Unfortunately, the mmap64() + // function is known to be broken in all Linux libcs (glibc, uclibc, musl + // and Bionic): all of them do the right shift, but don't confirm that the + // result fits into the 32-bit parameter to the kernel. + + static qint64 MaxFileOffset = (Q_INT64_C(1) << (32+12)) - 1; +#else + static qint64 MaxFileOffset = std::numeric_limits<QT_OFF_T>::max(); +#endif + Q_Q(QFSFileEngine); Q_UNUSED(flags); if (openMode == QIODevice::NotOpen) { @@ -695,7 +708,7 @@ uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size, QFile::MemoryMapFla return 0; } - if (offset < 0 || offset != qint64(QT_OFF_T(offset)) + if (offset < 0 || offset > MaxFileOffset || size < 0 || quint64(size) > quint64(size_t(-1))) { q->setError(QFile::UnspecifiedError, qt_error_string(int(EINVAL))); return 0; |