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author | Arvid Ephraim Picciani <arvid.picciani@nokia.com> | 2010-09-01 09:30:20 (GMT) |
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committer | Arvid Ephraim Picciani <arvid.picciani@nokia.com> | 2010-09-01 11:16:23 (GMT) |
commit | b80e006058d3b73db8a583981e471c334f0e6b93 (patch) | |
tree | c10c0ce37394f9f99da88c33285ecf62599b9922 /src/corelib/plugin/qelfparser_p.cpp | |
parent | f6e8ff07243b693dfc45bdeb4882e4f52f90930a (diff) | |
download | Qt-b80e006058d3b73db8a583981e471c334f0e6b93.zip Qt-b80e006058d3b73db8a583981e471c334f0e6b93.tar.gz Qt-b80e006058d3b73db8a583981e471c334f0e6b93.tar.bz2 |
Optimize plugin loading on ELF platforms
This is equal to 3c2a43f91e0225bde8d6e6d6076dfe2cddbc2f8e
except the alignment checks have been relaxed.
Reviewed-by: janarve
Diffstat (limited to 'src/corelib/plugin/qelfparser_p.cpp')
-rw-r--r-- | src/corelib/plugin/qelfparser_p.cpp | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/src/corelib/plugin/qelfparser_p.cpp b/src/corelib/plugin/qelfparser_p.cpp new file mode 100644 index 0000000..2e77ae7 --- /dev/null +++ b/src/corelib/plugin/qelfparser_p.cpp @@ -0,0 +1,234 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qlibrary_p.h" +#include "qelfparser_p.h" +#include <qdebug.h> + +QT_BEGIN_NAMESPACE + +// #define QELFPARSER_DEBUG 1 + +const char *QElfParser::parseSectionHeader(const char *data, ElfSectionHeader *sh) +{ + sh->name = read<qelfword_t>(data); + data += sizeof(qelfword_t); // sh_name + sh->type = read<qelfword_t>(data); + data += sizeof(qelfword_t) // sh_type + + sizeof(qelfaddr_t) // sh_flags + + sizeof(qelfaddr_t); // sh_addr + sh->offset = read<qelfoff_t>(data); + data += sizeof(qelfoff_t); // sh_offset + sh->size = read<qelfword_t>(data); + data += sizeof(qelfword_t); // sh_size + return data; +} + +int QElfParser::parse(const char *dataStart, ulong fdlen, const QString &library, QLibraryPrivate *lib, long *pos, ulong *sectionlen) +{ +#if defined(QELFPARSER_DEBUG) + qDebug() << "QElfParser::parse " << library; +#endif + + if (fdlen < 64){ + if (lib) + lib->errorString = QLibrary::tr("'%1' is not an ELF object (%2)").arg(library).arg(QLatin1String("file too small")); + return NotElf; + } + const char *data = dataStart; + if (qstrncmp(data, "\177ELF", 4) != 0) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is not an ELF object").arg(library); + return NotElf; + } + // 32 or 64 bit + if (data[4] != 1 && data[4] != 2) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library).arg(QLatin1String("odd cpu architecture")); + return Corrupt; + } + m_bits = (data[4] << 5); + + /* If you remove this check, to read ELF objects of a different arch, please make sure you modify the typedefs + to match the _plugin_ architecture. + */ + if ((sizeof(void*) == 4 && m_bits != 32) || (sizeof(void*) == 8 && m_bits != 64)) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library).arg(QLatin1String("wrong cpu architecture")); + return Corrupt; + } + // endian + if (data[5] == 0) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library).arg(QLatin1String("odd endianess")); + return Corrupt; + } + m_endian = (data[5] == 1 ? ElfLittleEndian : ElfBigEndian); + + data += 16 // e_ident + + sizeof(qelfhalf_t) // e_type + + sizeof(qelfhalf_t) // e_machine + + sizeof(qelfword_t) // e_version + + sizeof(qelfaddr_t) // e_entry + + sizeof(qelfoff_t); // e_phoff + + qelfoff_t e_shoff = read<qelfoff_t> (data); + data += sizeof(qelfoff_t) // e_shoff + + sizeof(qelfword_t); // e_flags + + qelfhalf_t e_shsize = read<qelfhalf_t> (data); + + if (e_shsize > fdlen) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library).arg(QLatin1String("unexpected e_shsize")); + return Corrupt; + } + + data += sizeof(qelfhalf_t) // e_ehsize + + sizeof(qelfhalf_t) // e_phentsize + + sizeof(qelfhalf_t); // e_phnum + + qelfhalf_t e_shentsize = read<qelfhalf_t> (data); + + if (e_shentsize % 4){ + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library).arg(QLatin1String("unexpected e_shentsize")); + return Corrupt; + } + data += sizeof(qelfhalf_t); // e_shentsize + qelfhalf_t e_shnum = read<qelfhalf_t> (data); + data += sizeof(qelfhalf_t); // e_shnum + qelfhalf_t e_shtrndx = read<qelfhalf_t> (data); + data += sizeof(qelfhalf_t); // e_shtrndx + + if ((e_shnum * e_shentsize) > fdlen) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library) + .arg(QLatin1String("announced %2 sections, each %3 bytes, exceed file size")) + .arg(e_shnum).arg(e_shentsize); + return Corrupt; + } + +#if defined(QELFPARSER_DEBUG) + qDebug() << e_shnum << "sections starting at " << ("0x" + QByteArray::number(e_shoff, 16)).data() << "each" << e_shentsize << "bytes"; +#endif + + ElfSectionHeader strtab; + qulonglong soff = e_shoff + e_shentsize * (e_shtrndx); + + if ((soff + e_shentsize) > fdlen || soff % 4 || soff == 0) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library) + .arg(QLatin1String("shstrtab section header seems to be at %1")) + .arg(QString::number(soff, 16)); + return Corrupt; + } + + parseSectionHeader(dataStart + soff, &strtab); + m_stringTableFileOffset = strtab.offset; + + if ((m_stringTableFileOffset + e_shentsize) >= fdlen || m_stringTableFileOffset == 0) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library) + .arg(QLatin1String("string table seems to be at %1")) + .arg(QString::number(soff, 16)); + return Corrupt; + } + +#if defined(QELFPARSER_DEBUG) + qDebug(".shstrtab at 0x%s", QByteArray::number(m_stringTableFileOffset, 16).data()); +#endif + + const char *s = dataStart + e_shoff; + for (int i = 0; i < e_shnum; ++i) { + ElfSectionHeader sh; + parseSectionHeader(s, &sh); + if (sh.name == 0) { + s += e_shentsize; + continue; + } + const char *shnam = dataStart + m_stringTableFileOffset + sh.name; + + if (m_stringTableFileOffset + sh.name > fdlen) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library) + .arg(QLatin1String("section name %2 of %3 behind end of file")) + .arg(i).arg(e_shnum); + return Corrupt; + } + +#if defined(QELFPARSER_DEBUG) + qDebug() << "++++" << i << shnam; +#endif + + if (qstrcmp(shnam, ".qtplugin") == 0 || qstrcmp(shnam, ".rodata") == 0) { + if (!(sh.type & 0x1)) { + if (shnam[1] == 'r') { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library) + .arg(QLatin1String("empty .rodata. not a library.")); + return Corrupt; + } +#if defined(QELFPARSER_DEBUG) + qDebug()<<"section is not program data. skipped."; +#endif + s += e_shentsize; + continue; + } + + if (sh.offset == 0 || (sh.offset + sh.size) > fdlen) { + if (lib) + lib->errorString = QLibrary::tr("'%1' is an invalid ELF object (%2)").arg(library) + .arg(QLatin1String("missing section data. This is not a library.")); + return Corrupt; + } + *pos = sh.offset; + *sectionlen = sh.size - 1; + if (shnam[1] == 'q') + return Ok; + } + s += e_shentsize; + } + return NoQtSection; +} + +QT_END_NAMESPACE + |