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/DebugInfo/DWARF/DWARFFormValue.h" 12 #include "llvm/Support/Errc.h" 13 #include "llvm/Support/Format.h" 14 #include "llvm/Support/raw_ostream.h" 15 #include <cassert> 16 #include <cinttypes> 17 #include <cstdint> 18 #include <cstring> 19 20 using namespace llvm; 21 22 void DWARFDebugArangeSet::Descriptor::dump(raw_ostream &OS, 23 uint32_t AddressSize) const { 24 OS << '['; 25 DWARFFormValue::dumpAddress(OS, AddressSize, Address); 26 OS << ", "; 27 DWARFFormValue::dumpAddress(OS, AddressSize, getEndAddress()); 28 OS << ')'; 29 } 30 31 void DWARFDebugArangeSet::clear() { 32 Offset = -1ULL; 33 std::memset(&HeaderData, 0, sizeof(Header)); 34 ArangeDescriptors.clear(); 35 } 36 37 Error DWARFDebugArangeSet::extract(DWARFDataExtractor data, 38 uint64_t *offset_ptr, 39 function_ref<void(Error)> WarningHandler) { 40 assert(data.isValidOffset(*offset_ptr)); 41 ArangeDescriptors.clear(); 42 Offset = *offset_ptr; 43 44 // 7.21 Address Range Table (extract) 45 // Each set of entries in the table of address ranges contained in 46 // the .debug_aranges section begins with a header containing: 47 // 1. unit_length (initial length) 48 // A 4-byte (32-bit DWARF) or 12-byte (64-bit DWARF) length containing 49 // the length of the set of entries for this compilation unit, 50 // not including the length field itself. 51 // 2. version (uhalf) 52 // The value in this field is 2. 53 // 3. debug_info_offset (section offset) 54 // A 4-byte (32-bit DWARF) or 8-byte (64-bit DWARF) offset into the 55 // .debug_info section of the compilation unit header. 56 // 4. address_size (ubyte) 57 // 5. segment_selector_size (ubyte) 58 // This header is followed by a series of tuples. Each tuple consists of 59 // a segment, an address and a length. The segment selector size is given by 60 // the segment_selector_size field of the header; the address and length 61 // size are each given by the address_size field of the header. Each set of 62 // tuples is terminated by a 0 for the segment, a 0 for the address and 0 63 // for the length. If the segment_selector_size field in the header is zero, 64 // the segment selectors are omitted from all tuples, including 65 // the terminating tuple. 66 67 Error Err = Error::success(); 68 std::tie(HeaderData.Length, HeaderData.Format) = 69 data.getInitialLength(offset_ptr, &Err); 70 HeaderData.Version = data.getU16(offset_ptr, &Err); 71 HeaderData.CuOffset = data.getUnsigned( 72 offset_ptr, dwarf::getDwarfOffsetByteSize(HeaderData.Format), &Err); 73 HeaderData.AddrSize = data.getU8(offset_ptr, &Err); 74 HeaderData.SegSize = data.getU8(offset_ptr, &Err); 75 if (Err) { 76 return createStringError(errc::invalid_argument, 77 "parsing address ranges table at offset 0x%" PRIx64 78 ": %s", 79 Offset, toString(std::move(Err)).c_str()); 80 } 81 82 // Perform basic validation of the header fields. 83 uint64_t full_length = 84 dwarf::getUnitLengthFieldByteSize(HeaderData.Format) + HeaderData.Length; 85 if (!data.isValidOffsetForDataOfSize(Offset, full_length)) 86 return createStringError(errc::invalid_argument, 87 "the length of address range table at offset " 88 "0x%" PRIx64 " exceeds section size", 89 Offset); 90 if (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8) 91 return createStringError(errc::invalid_argument, 92 "address range table at offset 0x%" PRIx64 93 " has unsupported address size: %d " 94 "(4 and 8 supported)", 95 Offset, HeaderData.AddrSize); 96 if (HeaderData.SegSize != 0) 97 return createStringError(errc::not_supported, 98 "non-zero segment selector size in address range " 99 "table at offset 0x%" PRIx64 " is not supported", 100 Offset); 101 102 // The first tuple following the header in each set begins at an offset that 103 // is a multiple of the size of a single tuple (that is, twice the size of 104 // an address because we do not support non-zero segment selector sizes). 105 // Therefore, the full length should also be a multiple of the tuple size. 106 const uint32_t tuple_size = HeaderData.AddrSize * 2; 107 if (full_length % tuple_size != 0) 108 return createStringError( 109 errc::invalid_argument, 110 "address range table at offset 0x%" PRIx64 111 " has length that is not a multiple of the tuple size", 112 Offset); 113 114 // The header is padded, if necessary, to the appropriate boundary. 115 const uint32_t header_size = *offset_ptr - Offset; 116 uint32_t first_tuple_offset = 0; 117 while (first_tuple_offset < header_size) 118 first_tuple_offset += tuple_size; 119 120 // There should be space for at least one tuple. 121 if (full_length <= first_tuple_offset) 122 return createStringError( 123 errc::invalid_argument, 124 "address range table at offset 0x%" PRIx64 125 " has an insufficient length to contain any entries", 126 Offset); 127 128 *offset_ptr = Offset + first_tuple_offset; 129 130 Descriptor arangeDescriptor; 131 132 static_assert(sizeof(arangeDescriptor.Address) == 133 sizeof(arangeDescriptor.Length), 134 "Different datatypes for addresses and sizes!"); 135 assert(sizeof(arangeDescriptor.Address) >= HeaderData.AddrSize); 136 137 uint64_t end_offset = Offset + full_length; 138 while (*offset_ptr < end_offset) { 139 uint64_t EntryOffset = *offset_ptr; 140 arangeDescriptor.Address = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 141 arangeDescriptor.Length = data.getUnsigned(offset_ptr, HeaderData.AddrSize); 142 143 // Each set of tuples is terminated by a 0 for the address and 0 144 // for the length. 145 if (arangeDescriptor.Length == 0 && arangeDescriptor.Address == 0) { 146 if (*offset_ptr == end_offset) 147 return ErrorSuccess(); 148 WarningHandler(createStringError( 149 errc::invalid_argument, 150 "address range table at offset 0x%" PRIx64 151 " has a premature terminator entry at offset 0x%" PRIx64, 152 Offset, EntryOffset)); 153 } 154 155 ArangeDescriptors.push_back(arangeDescriptor); 156 } 157 158 return createStringError(errc::invalid_argument, 159 "address range table at offset 0x%" PRIx64 160 " is not terminated by null entry", 161 Offset); 162 } 163 164 void DWARFDebugArangeSet::dump(raw_ostream &OS) const { 165 int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(HeaderData.Format); 166 OS << "Address Range Header: " 167 << format("length = 0x%0*" PRIx64 ", ", OffsetDumpWidth, HeaderData.Length) 168 << "format = " << dwarf::FormatString(HeaderData.Format) << ", " 169 << format("version = 0x%4.4x, ", HeaderData.Version) 170 << format("cu_offset = 0x%0*" PRIx64 ", ", OffsetDumpWidth, 171 HeaderData.CuOffset) 172 << format("addr_size = 0x%2.2x, ", HeaderData.AddrSize) 173 << format("seg_size = 0x%2.2x\n", HeaderData.SegSize); 174 175 for (const auto &Desc : ArangeDescriptors) { 176 Desc.dump(OS, HeaderData.AddrSize); 177 OS << '\n'; 178 } 179 } 180