1 //===- DWARFDebugArangeSet.cpp --------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h" 10 #include "llvm/BinaryFormat/Dwarf.h" 11 #include "llvm/Support/Errc.h" 12 #include "llvm/Support/Format.h" 13 #include "llvm/Support/raw_ostream.h" 14 #include <cassert> 15 #include <cinttypes> 16 #include <cstdint> 17 #include <cstring> 18 19 using namespace llvm; 20 21 void DWARFDebugArangeSet::Descriptor::dump(raw_ostream &OS, 22 uint32_t AddressSize) const { 23 OS << format("[0x%*.*" PRIx64 ", ", AddressSize * 2, AddressSize * 2, Address) 24 << format(" 0x%*.*" PRIx64 ")", AddressSize * 2, AddressSize * 2, 25 getEndAddress()); 26 } 27 28 void DWARFDebugArangeSet::clear() { 29 Offset = -1ULL; 30 std::memset(&HeaderData, 0, sizeof(Header)); 31 ArangeDescriptors.clear(); 32 } 33 34 Error DWARFDebugArangeSet::extract(DWARFDataExtractor data, 35 uint64_t *offset_ptr, 36 function_ref<void(Error)> WarningHandler) { 37 assert(data.isValidOffset(*offset_ptr)); 38 ArangeDescriptors.clear(); 39 Offset = *offset_ptr; 40 41 // 7.21 Address Range Table (extract) 42 // Each set of entries in the table of address ranges contained in 43 // the .debug_aranges section begins with a header containing: 44 // 1. unit_length (initial length) 45 // A 4-byte (32-bit DWARF) or 12-byte (64-bit DWARF) length containing 46 // the length of the set of entries for this compilation unit, 47 // not including the length field itself. 48 // 2. version (uhalf) 49 // The value in this field is 2. 50 // 3. debug_info_offset (section offset) 51 // A 4-byte (32-bit DWARF) or 8-byte (64-bit DWARF) offset into the 52 // .debug_info section of the compilation unit header. 53 // 4. address_size (ubyte) 54 // 5. segment_selector_size (ubyte) 55 // This header is followed by a series of tuples. Each tuple consists of 56 // a segment, an address and a length. The segment selector size is given by 57 // the segment_selector_size field of the header; the address and length 58 // size are each given by the address_size field of the header. Each set of 59 // tuples is terminated by a 0 for the segment, a 0 for the address and 0 60 // for the length. If the segment_selector_size field in the header is zero, 61 // the segment selectors are omitted from all tuples, including 62 // the terminating tuple. 63 64 Error Err = Error::success(); 65 std::tie(HeaderData.Length, HeaderData.Format) = 66 data.getInitialLength(offset_ptr, &Err); 67 HeaderData.Version = data.getU16(offset_ptr, &Err); 68 HeaderData.CuOffset = data.getUnsigned( 69 offset_ptr, dwarf::getDwarfOffsetByteSize(HeaderData.Format), &Err); 70 HeaderData.AddrSize = data.getU8(offset_ptr, &Err); 71 HeaderData.SegSize = data.getU8(offset_ptr, &Err); 72 if (Err) { 73 return createStringError(errc::invalid_argument, 74 "parsing address ranges table at offset 0x%" PRIx64 75 ": %s", 76 Offset, toString(std::move(Err)).c_str()); 77 } 78 79 // Perform basic validation of the header fields. 80 uint64_t full_length = 81 dwarf::getUnitLengthFieldByteSize(HeaderData.Format) + HeaderData.Length; 82 if (!data.isValidOffsetForDataOfSize(Offset, full_length)) 83 return createStringError(errc::invalid_argument, 84 "the length of address range table at offset " 85 "0x%" PRIx64 " exceeds section size", 86 Offset); 87 if (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8) 88 return createStringError(errc::invalid_argument, 89 "address range table at offset 0x%" PRIx64 90 " has unsupported address size: %d " 91 "(4 and 8 supported)", 92 Offset, HeaderData.AddrSize); 93 if (HeaderData.SegSize != 0) 94 return createStringError(errc::not_supported, 95 "non-zero segment selector size in address range " 96 "table at offset 0x%" PRIx64 " is not supported", 97 Offset); 98 99 // The first tuple following the header in each set begins at an offset that 100 // is a multiple of the size of a single tuple (that is, twice the size of 101 // an address because we do not support non-zero segment selector sizes). 102 // Therefore, the full length should also be a multiple of the tuple size. 103 const uint32_t tuple_size = HeaderData.AddrSize * 2; 104 if (full_length % tuple_size != 0) 105 return createStringError( 106 errc::invalid_argument, 107 "address range table at offset 0x%" PRIx64 108 " has length that is not a multiple of the tuple size", 109 Offset); 110 111 // The header is padded, if necessary, to the appropriate boundary. 112 const uint32_t header_size = *offset_ptr - Offset; 113 uint32_t first_tuple_offset = 0; 114 while (first_tuple_offset < header_size) 115 first_tuple_offset += tuple_size; 116 117 // There should be space for at least one tuple. 118 if (full_length <= first_tuple_offset) 119 return createStringError( 120 errc::invalid_argument, 121 "address range table at offset 0x%" PRIx64 122 " has an insufficient length to contain any entries", 123 Offset); 124 125 *offset_ptr = Offset + first_tuple_offset; 126 127 Descriptor arangeDescriptor; 128 129 static_assert(sizeof(arangeDescriptor.Address) == 130 sizeof(arangeDescriptor.Length), 131 "Different datatypes for addresses and sizes!"); 132 assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize); 133 134 uint64_t end_offset = Offset + full_length; 135 while (*offset_ptr < end_offset) { 136 uint64_t EntryOffset = *offset_ptr; 137 arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 138 arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 139 140 // Each set of tuples is terminated by a 0 for the address and 0 141 // for the length. 142 if (arangeDescriptor.Length == 0 && arangeDescriptor.Address == 0) { 143 if (*offset_ptr == end_offset) 144 return ErrorSuccess(); 145 WarningHandler(createStringError( 146 errc::invalid_argument, 147 "address range table at offset 0x%" PRIx64 148 " has a premature terminator entry at offset 0x%" PRIx64, 149 Offset, EntryOffset)); 150 } 151 152 ArangeDescriptors.push_back(arangeDescriptor); 153 } 154 155 return createStringError(errc::invalid_argument, 156 "address range table at offset 0x%" PRIx64 157 " is not terminated by null entry", 158 Offset); 159 } 160 161 void DWARFDebugArangeSet::dump(raw_ostream &OS) const { 162 int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(HeaderData.Format); 163 OS << "Address Range Header: " 164 << format("length = 0x%0*" PRIx64 ", ", OffsetDumpWidth, HeaderData.Length) 165 << "format = " << dwarf::FormatString(HeaderData.Format) << ", " 166 << format("version = 0x%4.4x, ", HeaderData.Version) 167 << format("cu_offset = 0x%0*" PRIx64 ", ", OffsetDumpWidth, 168 HeaderData.CuOffset) 169 << format("addr_size = 0x%2.2x, ", HeaderData.AddrSize) 170 << format("seg_size = 0x%2.2x\n", HeaderData.SegSize); 171 172 for (const auto &Desc : ArangeDescriptors) { 173 Desc.dump(OS, HeaderData.AddrSize); 174 OS << '\n'; 175 } 176 } 177