1affc150dc44fab1911775a49636d0ce85333b634Zonr Chang//===- EhFrameHdr.cpp -----------------------------------------------------===// 2affc150dc44fab1911775a49636d0ce85333b634Zonr Chang// 3affc150dc44fab1911775a49636d0ce85333b634Zonr Chang// The MCLinker Project 4affc150dc44fab1911775a49636d0ce85333b634Zonr Chang// 5affc150dc44fab1911775a49636d0ce85333b634Zonr Chang// This file is distributed under the University of Illinois Open Source 6affc150dc44fab1911775a49636d0ce85333b634Zonr Chang// License. See LICENSE.TXT for details. 7affc150dc44fab1911775a49636d0ce85333b634Zonr Chang// 8affc150dc44fab1911775a49636d0ce85333b634Zonr Chang//===----------------------------------------------------------------------===// 937b74a387bb3993387029859c2d9d051c41c724eStephen Hines#include "mcld/LD/EhFrameHdr.h" 10affc150dc44fab1911775a49636d0ce85333b634Zonr Chang 1137b74a387bb3993387029859c2d9d051c41c724eStephen Hines#include "mcld/LD/EhFrame.h" 1237b74a387bb3993387029859c2d9d051c41c724eStephen Hines#include "mcld/LD/LDSection.h" 1322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 1422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao#include <llvm/Support/Dwarf.h> 1522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao#include <llvm/Support/DataTypes.h> 1622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 1722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao#include <algorithm> 1822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao#include <cstring> 1922add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 2037b74a387bb3993387029859c2d9d051c41c724eStephen Hinesnamespace mcld { 21affc150dc44fab1911775a49636d0ce85333b634Zonr Chang 2222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao//===----------------------------------------------------------------------===// 2322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao// Helper Function 2422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao//===----------------------------------------------------------------------===// 2522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liaonamespace bit32 { 2622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 2722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liaotypedef std::pair<SizeTraits<32>::Address, SizeTraits<32>::Address> Entry; 2822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 2937b74a387bb3993387029859c2d9d051c41c724eStephen Hinesbool EntryCompare(const Entry& pX, const Entry& pY) { 3037b74a387bb3993387029859c2d9d051c41c724eStephen Hines return (pX.first < pY.first); 3137b74a387bb3993387029859c2d9d051c41c724eStephen Hines} 3222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 3337b74a387bb3993387029859c2d9d051c41c724eStephen Hines} // namespace bit32 3422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 3522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao//===----------------------------------------------------------------------===// 3622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao// Template Specification Functions 3722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao//===----------------------------------------------------------------------===// 3822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao/// emitOutput<32> - write out eh_frame_hdr 3937b74a387bb3993387029859c2d9d051c41c724eStephen Hinestemplate <> 4037b74a387bb3993387029859c2d9d051c41c724eStephen Hinesvoid EhFrameHdr::emitOutput<32>(FileOutputBuffer& pOutput) { 4137b74a387bb3993387029859c2d9d051c41c724eStephen Hines MemoryRegion ehframehdr_region = 4237b74a387bb3993387029859c2d9d051c41c724eStephen Hines pOutput.request(m_EhFrameHdr.offset(), m_EhFrameHdr.size()); 4322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 4437b74a387bb3993387029859c2d9d051c41c724eStephen Hines MemoryRegion ehframe_region = 4537b74a387bb3993387029859c2d9d051c41c724eStephen Hines pOutput.request(m_EhFrame.offset(), m_EhFrame.size()); 4622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 47f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines uint8_t* data = ehframehdr_region.begin(); 4822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // version 4922add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao data[0] = 1; 5022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // eh_frame_ptr_enc 5137b74a387bb3993387029859c2d9d051c41c724eStephen Hines data[1] = llvm::dwarf::DW_EH_PE_pcrel | llvm::dwarf::DW_EH_PE_sdata4; 5222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 5322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // eh_frame_ptr 5437b74a387bb3993387029859c2d9d051c41c724eStephen Hines uint32_t* eh_frame_ptr = reinterpret_cast<uint32_t*>(data + 4); 5522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao *eh_frame_ptr = m_EhFrame.addr() - (m_EhFrameHdr.addr() + 4); 5622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 5722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // fde_count 5837b74a387bb3993387029859c2d9d051c41c724eStephen Hines uint32_t* fde_count = reinterpret_cast<uint32_t*>(data + 8); 5922add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao if (m_EhFrame.hasEhFrame()) 6022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao *fde_count = m_EhFrame.getEhFrame()->numOfFDEs(); 61f7ac0f19a1c8d0ad14bcf6456ce368b830fea886Stephen Hines else 62f7ac0f19a1c8d0ad14bcf6456ce368b830fea886Stephen Hines *fde_count = 0; 6322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 6437b74a387bb3993387029859c2d9d051c41c724eStephen Hines if (*fde_count == 0) { 6522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // fde_count_enc 6637b74a387bb3993387029859c2d9d051c41c724eStephen Hines data[2] = llvm::dwarf::DW_EH_PE_omit; 6722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // table_enc 6837b74a387bb3993387029859c2d9d051c41c724eStephen Hines data[3] = llvm::dwarf::DW_EH_PE_omit; 6937b74a387bb3993387029859c2d9d051c41c724eStephen Hines } else { 7022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // fde_count_enc 7137b74a387bb3993387029859c2d9d051c41c724eStephen Hines data[2] = llvm::dwarf::DW_EH_PE_udata4; 7222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // table_enc 7337b74a387bb3993387029859c2d9d051c41c724eStephen Hines data[3] = llvm::dwarf::DW_EH_PE_datarel | llvm::dwarf::DW_EH_PE_sdata4; 7422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 7522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // prepare the binary search table 7622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao typedef std::vector<bit32::Entry> SearchTableType; 7722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao SearchTableType search_table; 78f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines 79f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines for (EhFrame::const_cie_iterator i = m_EhFrame.getEhFrame()->cie_begin(), 8037b74a387bb3993387029859c2d9d051c41c724eStephen Hines e = m_EhFrame.getEhFrame()->cie_end(); 8137b74a387bb3993387029859c2d9d051c41c724eStephen Hines i != e; 8237b74a387bb3993387029859c2d9d051c41c724eStephen Hines ++i) { 83f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines EhFrame::CIE& cie = **i; 84f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines for (EhFrame::const_fde_iterator fi = cie.begin(), fe = cie.end(); 8537b74a387bb3993387029859c2d9d051c41c724eStephen Hines fi != fe; 8637b74a387bb3993387029859c2d9d051c41c724eStephen Hines ++fi) { 87f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines EhFrame::FDE& fde = **fi; 88f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines SizeTraits<32>::Offset offset; 89f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines SizeTraits<32>::Address fde_pc; 90f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines SizeTraits<32>::Address fde_addr; 91f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines offset = fde.getOffset(); 92f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines fde_pc = computePCBegin(fde, ehframe_region); 93f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines fde_addr = m_EhFrame.addr() + offset; 94f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines search_table.push_back(std::make_pair(fde_pc, fde_addr)); 95f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines } 9622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao } 9722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 9822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao std::sort(search_table.begin(), search_table.end(), bit32::EntryCompare); 9922add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 10022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // write out the binary search table 10137b74a387bb3993387029859c2d9d051c41c724eStephen Hines uint32_t* bst = reinterpret_cast<uint32_t*>(data + 12); 10222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao SearchTableType::const_iterator entry, entry_end = search_table.end(); 10322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao size_t id = 0; 10422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao for (entry = search_table.begin(); entry != entry_end; ++entry) { 10522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao bst[id++] = (*entry).first - m_EhFrameHdr.addr(); 10622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao bst[id++] = (*entry).second - m_EhFrameHdr.addr(); 10722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao } 10822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao } 10922add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao} 11022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 11122add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao//===----------------------------------------------------------------------===// 11222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao// EhFrameHdr 11322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao//===----------------------------------------------------------------------===// 11422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 11522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei LiaoEhFrameHdr::EhFrameHdr(LDSection& pEhFrameHdr, const LDSection& pEhFrame) 11637b74a387bb3993387029859c2d9d051c41c724eStephen Hines : m_EhFrameHdr(pEhFrameHdr), m_EhFrame(pEhFrame) { 117affc150dc44fab1911775a49636d0ce85333b634Zonr Chang} 118affc150dc44fab1911775a49636d0ce85333b634Zonr Chang 11937b74a387bb3993387029859c2d9d051c41c724eStephen HinesEhFrameHdr::~EhFrameHdr() { 120affc150dc44fab1911775a49636d0ce85333b634Zonr Chang} 121affc150dc44fab1911775a49636d0ce85333b634Zonr Chang 122affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// @ref lsb core generic 4.1 123affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// .eh_frame_hdr section format 124affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// uint8_t : version 125affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// uint8_t : eh_frame_ptr_enc 126affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// uint8_t : fde_count_enc 127affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// uint8_t : table_enc 128affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// uint32_t : eh_frame_ptr 129affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// uint32_t : fde_count 130affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// __________________________ when fde_count > 0 131affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// <uint32_t, uint32_t>+ : binary search table 132affc150dc44fab1911775a49636d0ce85333b634Zonr Chang/// sizeOutput - base on the fde count to size output 13337b74a387bb3993387029859c2d9d051c41c724eStephen Hinesvoid EhFrameHdr::sizeOutput() { 134affc150dc44fab1911775a49636d0ce85333b634Zonr Chang size_t size = 12; 13522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao if (m_EhFrame.hasEhFrame()) 13622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao size += 8 * m_EhFrame.getEhFrame()->numOfFDEs(); 13722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao m_EhFrameHdr.setSize(size); 138affc150dc44fab1911775a49636d0ce85333b634Zonr Chang} 139affc150dc44fab1911775a49636d0ce85333b634Zonr Chang 14022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao/// computePCBegin - return the address of FDE's pc 14122add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liaouint32_t EhFrameHdr::computePCBegin(const EhFrame::FDE& pFDE, 14237b74a387bb3993387029859c2d9d051c41c724eStephen Hines const MemoryRegion& pEhFrameRegion) { 14322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao uint8_t fde_encoding = pFDE.getCIE().getFDEEncode(); 14422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao unsigned int eh_value = fde_encoding & 0x7; 14522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 14622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // check the size to read in 14722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao if (eh_value == llvm::dwarf::DW_EH_PE_absptr) { 14837b74a387bb3993387029859c2d9d051c41c724eStephen Hines eh_value = llvm::dwarf::DW_EH_PE_udata4; 14922add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao } 15022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 15122add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao size_t pc_size = 0x0; 15222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao switch (eh_value) { 15337b74a387bb3993387029859c2d9d051c41c724eStephen Hines case llvm::dwarf::DW_EH_PE_udata2: 15422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao pc_size = 2; 15522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 15637b74a387bb3993387029859c2d9d051c41c724eStephen Hines case llvm::dwarf::DW_EH_PE_udata4: 15722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao pc_size = 4; 15822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 15937b74a387bb3993387029859c2d9d051c41c724eStephen Hines case llvm::dwarf::DW_EH_PE_udata8: 16022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao pc_size = 8; 16122add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 16222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao default: 16322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // TODO 16422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 16522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao } 16622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 16722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao SizeTraits<32>::Address pc = 0x0; 16837b74a387bb3993387029859c2d9d051c41c724eStephen Hines const uint8_t* offset = (const uint8_t*)pEhFrameRegion.begin() + 16937b74a387bb3993387029859c2d9d051c41c724eStephen Hines pFDE.getOffset() + EhFrame::getDataStartOffset<32>(); 17022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao std::memcpy(&pc, offset, pc_size); 17122add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 17222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // adjust the signed value 17322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao bool is_signed = (fde_encoding & llvm::dwarf::DW_EH_PE_signed) != 0x0; 17437b74a387bb3993387029859c2d9d051c41c724eStephen Hines if (llvm::dwarf::DW_EH_PE_udata2 == eh_value && is_signed) 17522add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao pc = (pc ^ 0x8000) - 0x8000; 17622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao 17722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // handle eh application 17837b74a387bb3993387029859c2d9d051c41c724eStephen Hines switch (fde_encoding & 0x70) { 17937b74a387bb3993387029859c2d9d051c41c724eStephen Hines case llvm::dwarf::DW_EH_PE_absptr: 18022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 18137b74a387bb3993387029859c2d9d051c41c724eStephen Hines case llvm::dwarf::DW_EH_PE_pcrel: 182f33f6de54db174aa679a4b6d1e040d37e95541c0Stephen Hines pc += m_EhFrame.addr() + pFDE.getOffset() + 18337b74a387bb3993387029859c2d9d051c41c724eStephen Hines EhFrame::getDataStartOffset<32>(); 18422add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 18537b74a387bb3993387029859c2d9d051c41c724eStephen Hines case llvm::dwarf::DW_EH_PE_datarel: 18622add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // TODO 18722add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 18822add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao default: 18922add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao // TODO 19022add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao break; 19122add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao } 19222add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao return pc; 19322add6ff3426df1a85089fe6a6e1597ee3b6f300Shih-wei Liao} 19437b74a387bb3993387029859c2d9d051c41c724eStephen Hines 19537b74a387bb3993387029859c2d9d051c41c724eStephen Hines} // namespace mcld 196