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