compute-runtime/elf/reader.cpp

115 lines
4.4 KiB
C++

/*
* Copyright (c) 2017 - 2018, Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include "reader.h"
#include <string.h>
namespace CLElfLib {
CElfReader::CElfReader(ElfBinaryStorage &elfBinary) {
validateElfBinary(elfBinary);
}
void CElfReader::validateElfBinary(ElfBinaryStorage &elfBinary) {
const char *nameTable = nullptr;
const char *end = nullptr;
size_t ourSize = 0u;
size_t entrySize = 0u;
size_t indexedSectionHeaderOffset = 0u;
beginBinary = elfBinary.data();
if (elfBinary.size() >= sizeof(SElf64Header)) {
// calculate a pointer to the end
end = beginBinary + elfBinary.size();
elf64Header = reinterpret_cast<const SElf64Header *>(elfBinary.data());
if (!((elf64Header->Identity[ELFConstants::idIdxMagic0] == ELFConstants::elfMag0) &&
(elf64Header->Identity[ELFConstants::idIdxMagic1] == ELFConstants::elfMag1) &&
(elf64Header->Identity[ELFConstants::idIdxMagic2] == ELFConstants::elfMag2) &&
(elf64Header->Identity[ELFConstants::idIdxMagic3] == ELFConstants::elfMag3) &&
(elf64Header->Identity[ELFConstants::idIdxClass] == static_cast<uint32_t>(E_EH_CLASS::EH_CLASS_64)))) {
throw ElfException();
}
ourSize += elf64Header->ElfHeaderSize;
} else {
throw ElfException();
}
entrySize = elf64Header->SectionHeaderEntrySize;
if (elf64Header->SectionNameTableIndex < elf64Header->NumSectionHeaderEntries) {
indexedSectionHeaderOffset = static_cast<size_t>(elf64Header->SectionHeadersOffset) + (elf64Header->SectionNameTableIndex * entrySize);
if ((beginBinary + indexedSectionHeaderOffset) <= end) {
nameTable = beginBinary + indexedSectionHeaderOffset;
}
}
for (uint16_t i = 0u; i < elf64Header->NumSectionHeaderEntries; ++i) {
indexedSectionHeaderOffset = static_cast<size_t>(elf64Header->SectionHeadersOffset) + (i * entrySize);
// check section header offset
if ((beginBinary + indexedSectionHeaderOffset) > end) {
throw ElfException();
}
const SElf64SectionHeader *sectionHeader = nullptr;
sectionHeader = reinterpret_cast<const SElf64SectionHeader *>(beginBinary + indexedSectionHeaderOffset);
// check section data
if ((beginBinary + sectionHeader->DataOffset + sectionHeader->DataSize) > end) {
throw ElfException();
}
// check section name index
if ((nameTable + sectionHeader->Name) > end) {
throw ElfException();
}
SElf64SectionHeader stringSectionHeader = {0};
stringSectionHeader.Type = sectionHeader->Type;
stringSectionHeader.Flags = sectionHeader->Flags;
stringSectionHeader.DataOffset = sectionHeader->DataOffset;
stringSectionHeader.DataSize = sectionHeader->DataSize;
stringSectionHeader.Name = sectionHeader->Name;
sectionHeaders.push_back(std::move(stringSectionHeader));
// tally up the sizes
ourSize += static_cast<size_t>(sectionHeader->DataSize);
ourSize += static_cast<size_t>(entrySize);
}
if (ourSize != elfBinary.size()) {
throw ElfException();
}
}
char *CElfReader::getSectionData(Elf64_Off dataOffset) {
return beginBinary + dataOffset;
}
const SElf64Header *CElfReader::getElfHeader() {
return elf64Header;
}
} // namespace CLElfLib