| 862 | |
| 863 | |
| 864 | void MachoView::RebaseThreadStarts(BinaryReader& virtualReader, vector<uint32_t>& threadStarts, uint64_t stepMultiplier) |
| 865 | { |
| 866 | std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now(); |
| 867 | |
| 868 | // create a dummy relocation to handle tagged pointers |
| 869 | BNRelocationInfo reloc; |
| 870 | memset(&reloc, 0, sizeof(BNRelocationInfo)); |
| 871 | reloc.type = StandardRelocationType; |
| 872 | reloc.size = 8; |
| 873 | reloc.nativeType = BINARYNINJA_MANUAL_RELOCATION; |
| 874 | |
| 875 | size_t numReg = 0; |
| 876 | size_t numAuth = 0; |
| 877 | uint64_t imageBase = GetStart(); |
| 878 | for (auto threadStart : threadStarts) |
| 879 | { |
| 880 | if (threadStart == 0xffffffff) |
| 881 | break; |
| 882 | |
| 883 | m_logger->LogDebug("Rebasing thread chain start: 0x%x", threadStart); |
| 884 | try |
| 885 | { |
| 886 | uint64_t curAddr = imageBase + threadStart; |
| 887 | virtualReader.Seek(curAddr); |
| 888 | while (true) |
| 889 | { |
| 890 | if (!IsOffsetBackedByFile(virtualReader.GetOffset())) |
| 891 | { |
| 892 | m_logger->LogError("Chained address: 0x%" PRIx64 " in thread start: 0x%x not backed by file!", virtualReader.GetOffset(), threadStart); |
| 893 | break; |
| 894 | } |
| 895 | |
| 896 | // read tagged pointer |
| 897 | uint64_t val = virtualReader.Read64(); |
| 898 | bool isAuthenticated = (val & (1ULL << 63)) != 0; |
| 899 | bool isRebase = (val & (1ULL << 62)) == 0; |
| 900 | if (isRebase) |
| 901 | { |
| 902 | // calculate new target value |
| 903 | uint64_t tgtVal; |
| 904 | if (isAuthenticated) |
| 905 | { |
| 906 | numAuth++; |
| 907 | tgtVal = (val & 0xFFFFFFFF) + imageBase; |
| 908 | } |
| 909 | else |
| 910 | { |
| 911 | numReg++; |
| 912 | uint64_t top8Bits = val & 0x0007F80000000000ULL; |
| 913 | uint64_t bottom43Bits = val & 0x000007FFFFFFFFFFULL; |
| 914 | tgtVal = (top8Bits << 13) | (((int64_t)(bottom43Bits << 21) >> 21) & 0x00FFFFFFFFFFFFFF); |
| 915 | tgtVal += m_imageBaseAdjustment; |
| 916 | } |
| 917 | |
| 918 | reloc.address = curAddr; |
| 919 | DefineRelocation(m_arch, reloc, tgtVal, reloc.address); |
| 920 | } |
| 921 | |