1 //===- DWARFVerifier.h ----------------------------------------------------===// 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 #ifndef LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H 10 #define LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H 11 12 #include "llvm/ADT/Optional.h" 13 #include "llvm/DebugInfo/DIContext.h" 14 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h" 15 #include "llvm/DebugInfo/DWARF/DWARFDie.h" 16 #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h" 17 #include <cstdint> 18 #include <map> 19 #include <set> 20 21 namespace llvm { 22 class raw_ostream; 23 struct DWARFAddressRange; 24 struct DWARFAttribute; 25 class DWARFContext; 26 class DWARFDataExtractor; 27 class DWARFDebugAbbrev; 28 class DataExtractor; 29 struct DWARFSection; 30 class DWARFUnit; 31 32 /// A class that verifies DWARF debug information given a DWARF Context. 33 class DWARFVerifier { 34 public: 35 /// A class that keeps the address range information for a single DIE. 36 struct DieRangeInfo { 37 DWARFDie Die; 38 39 /// Sorted DWARFAddressRanges. 40 std::vector<DWARFAddressRange> Ranges; 41 42 /// Sorted DWARFAddressRangeInfo. 43 std::set<DieRangeInfo> Children; 44 45 DieRangeInfo() = default; DieRangeInfoDieRangeInfo46 DieRangeInfo(DWARFDie Die) : Die(Die) {} 47 48 /// Used for unit testing. DieRangeInfoDieRangeInfo49 DieRangeInfo(std::vector<DWARFAddressRange> Ranges) 50 : Ranges(std::move(Ranges)) {} 51 52 typedef std::vector<DWARFAddressRange>::const_iterator 53 address_range_iterator; 54 typedef std::set<DieRangeInfo>::const_iterator die_range_info_iterator; 55 56 /// Inserts the address range. If the range overlaps with an existing 57 /// range, the range that it overlaps with will be returned and the two 58 /// address ranges will be unioned together in "Ranges". 59 /// 60 /// This is used for finding overlapping ranges in the DW_AT_ranges 61 /// attribute of a DIE. It is also used as a set of address ranges that 62 /// children address ranges must all be contained in. 63 Optional<DWARFAddressRange> insert(const DWARFAddressRange &R); 64 65 /// Finds an address range in the sorted vector of ranges. findRangeDieRangeInfo66 address_range_iterator findRange(const DWARFAddressRange &R) const { 67 auto Begin = Ranges.begin(); 68 auto End = Ranges.end(); 69 auto Iter = std::upper_bound(Begin, End, R); 70 if (Iter != Begin) 71 --Iter; 72 return Iter; 73 } 74 75 /// Inserts the address range info. If any of its ranges overlaps with a 76 /// range in an existing range info, the range info is *not* added and an 77 /// iterator to the overlapping range info. 78 /// 79 /// This is used for finding overlapping children of the same DIE. 80 die_range_info_iterator insert(const DieRangeInfo &RI); 81 82 /// Return true if ranges in this object contains all ranges within RHS. 83 bool contains(const DieRangeInfo &RHS) const; 84 85 /// Return true if any range in this object intersects with any range in 86 /// RHS. 87 bool intersects(const DieRangeInfo &RHS) const; 88 }; 89 90 private: 91 raw_ostream &OS; 92 DWARFContext &DCtx; 93 DIDumpOptions DumpOpts; 94 /// A map that tracks all references (converted absolute references) so we 95 /// can verify each reference points to a valid DIE and not an offset that 96 /// lies between to valid DIEs. 97 std::map<uint64_t, std::set<uint64_t>> ReferenceToDIEOffsets; 98 uint32_t NumDebugLineErrors = 0; 99 // Used to relax some checks that do not currently work portably 100 bool IsObjectFile; 101 bool IsMachOObject; 102 103 raw_ostream &error() const; 104 raw_ostream &warn() const; 105 raw_ostream ¬e() const; 106 raw_ostream &dump(const DWARFDie &Die, unsigned indent = 0) const; 107 108 /// Verifies the abbreviations section. 109 /// 110 /// This function currently checks that: 111 /// --No abbreviation declaration has more than one attributes with the same 112 /// name. 113 /// 114 /// \param Abbrev Pointer to the abbreviations section we are verifying 115 /// Abbrev can be a pointer to either .debug_abbrev or debug_abbrev.dwo. 116 /// 117 /// \returns The number of errors that occurred during verification. 118 unsigned verifyAbbrevSection(const DWARFDebugAbbrev *Abbrev); 119 120 /// Verifies the header of a unit in a .debug_info or .debug_types section. 121 /// 122 /// This function currently checks for: 123 /// - Unit is in 32-bit DWARF format. The function can be modified to 124 /// support 64-bit format. 125 /// - The DWARF version is valid 126 /// - The unit type is valid (if unit is in version >=5) 127 /// - The unit doesn't extend beyond the containing section 128 /// - The address size is valid 129 /// - The offset in the .debug_abbrev section is valid 130 /// 131 /// \param DebugInfoData The section data 132 /// \param Offset A reference to the offset start of the unit. The offset will 133 /// be updated to point to the next unit in the section 134 /// \param UnitIndex The index of the unit to be verified 135 /// \param UnitType A reference to the type of the unit 136 /// \param isUnitDWARF64 A reference to a flag that shows whether the unit is 137 /// in 64-bit format. 138 /// 139 /// \returns true if the header is verified successfully, false otherwise. 140 bool verifyUnitHeader(const DWARFDataExtractor DebugInfoData, 141 uint64_t *Offset, unsigned UnitIndex, uint8_t &UnitType, 142 bool &isUnitDWARF64); 143 144 /// Verifies the header of a unit in a .debug_info or .debug_types section. 145 /// 146 /// This function currently verifies: 147 /// - The debug info attributes. 148 /// - The debug info form=s. 149 /// - The presence of a root DIE. 150 /// - That the root DIE is a unit DIE. 151 /// - If a unit type is provided, that the unit DIE matches the unit type. 152 /// - The DIE ranges. 153 /// - That call site entries are only nested within subprograms with a 154 /// DW_AT_call attribute. 155 /// 156 /// \param Unit The DWARF Unit to verify. 157 /// 158 /// \returns The number of errors that occurred during verification. 159 unsigned verifyUnitContents(DWARFUnit &Unit); 160 161 /// Verifies the unit headers and contents in a .debug_info or .debug_types 162 /// section. 163 /// 164 /// \param S The DWARF Section to verify. 165 /// \param SectionKind The object-file section kind that S comes from. 166 /// 167 /// \returns The number of errors that occurred during verification. 168 unsigned verifyUnitSection(const DWARFSection &S, 169 DWARFSectionKind SectionKind); 170 171 /// Verifies that a call site entry is nested within a subprogram with a 172 /// DW_AT_call attribute. 173 /// 174 /// \returns Number of errors that occurred during verification. 175 unsigned verifyDebugInfoCallSite(const DWARFDie &Die); 176 177 /// Verify that all Die ranges are valid. 178 /// 179 /// This function currently checks for: 180 /// - cases in which lowPC >= highPC 181 /// 182 /// \returns Number of errors that occurred during verification. 183 unsigned verifyDieRanges(const DWARFDie &Die, DieRangeInfo &ParentRI); 184 185 /// Verifies the attribute's DWARF attribute and its value. 186 /// 187 /// This function currently checks for: 188 /// - DW_AT_ranges values is a valid .debug_ranges offset 189 /// - DW_AT_stmt_list is a valid .debug_line offset 190 /// 191 /// \param Die The DWARF DIE that owns the attribute value 192 /// \param AttrValue The DWARF attribute value to check 193 /// 194 /// \returns NumErrors The number of errors occurred during verification of 195 /// attributes' values in a unit 196 unsigned verifyDebugInfoAttribute(const DWARFDie &Die, 197 DWARFAttribute &AttrValue); 198 199 /// Verifies the attribute's DWARF form. 200 /// 201 /// This function currently checks for: 202 /// - All DW_FORM_ref values that are CU relative have valid CU offsets 203 /// - All DW_FORM_ref_addr values have valid section offsets 204 /// - All DW_FORM_strp values have valid .debug_str offsets 205 /// 206 /// \param Die The DWARF DIE that owns the attribute value 207 /// \param AttrValue The DWARF attribute value to check 208 /// 209 /// \returns NumErrors The number of errors occurred during verification of 210 /// attributes' forms in a unit 211 unsigned verifyDebugInfoForm(const DWARFDie &Die, DWARFAttribute &AttrValue); 212 213 /// Verifies the all valid references that were found when iterating through 214 /// all of the DIE attributes. 215 /// 216 /// This function will verify that all references point to DIEs whose DIE 217 /// offset matches. This helps to ensure if a DWARF link phase moved things 218 /// around, that it doesn't create invalid references by failing to relocate 219 /// CU relative and absolute references. 220 /// 221 /// \returns NumErrors The number of errors occurred during verification of 222 /// references for the .debug_info and .debug_types sections 223 unsigned verifyDebugInfoReferences(); 224 225 /// Verify the DW_AT_stmt_list encoding and value and ensure that no 226 /// compile units that have the same DW_AT_stmt_list value. 227 void verifyDebugLineStmtOffsets(); 228 229 /// Verify that all of the rows in the line table are valid. 230 /// 231 /// This function currently checks for: 232 /// - addresses within a sequence that decrease in value 233 /// - invalid file indexes 234 void verifyDebugLineRows(); 235 236 /// Verify that an Apple-style accelerator table is valid. 237 /// 238 /// This function currently checks that: 239 /// - The fixed part of the header fits in the section 240 /// - The size of the section is as large as what the header describes 241 /// - There is at least one atom 242 /// - The form for each atom is valid 243 /// - The tag for each DIE in the table is valid 244 /// - The buckets have a valid index, or they are empty 245 /// - Each hashdata offset is valid 246 /// - Each DIE is valid 247 /// 248 /// \param AccelSection pointer to the section containing the acceleration table 249 /// \param StrData pointer to the string section 250 /// \param SectionName the name of the table we're verifying 251 /// 252 /// \returns The number of errors occurred during verification 253 unsigned verifyAppleAccelTable(const DWARFSection *AccelSection, 254 DataExtractor *StrData, 255 const char *SectionName); 256 257 unsigned verifyDebugNamesCULists(const DWARFDebugNames &AccelTable); 258 unsigned verifyNameIndexBuckets(const DWARFDebugNames::NameIndex &NI, 259 const DataExtractor &StrData); 260 unsigned verifyNameIndexAbbrevs(const DWARFDebugNames::NameIndex &NI); 261 unsigned verifyNameIndexAttribute(const DWARFDebugNames::NameIndex &NI, 262 const DWARFDebugNames::Abbrev &Abbr, 263 DWARFDebugNames::AttributeEncoding AttrEnc); 264 unsigned verifyNameIndexEntries(const DWARFDebugNames::NameIndex &NI, 265 const DWARFDebugNames::NameTableEntry &NTE); 266 unsigned verifyNameIndexCompleteness(const DWARFDie &Die, 267 const DWARFDebugNames::NameIndex &NI); 268 269 /// Verify that the DWARF v5 accelerator table is valid. 270 /// 271 /// This function currently checks that: 272 /// - Headers individual Name Indices fit into the section and can be parsed. 273 /// - Abbreviation tables can be parsed and contain valid index attributes 274 /// with correct form encodings. 275 /// - The CU lists reference existing compile units. 276 /// - The buckets have a valid index, or they are empty. 277 /// - All names are reachable via the hash table (they have the correct hash, 278 /// and the hash is in the correct bucket). 279 /// - Information in the index entries is complete (all required entries are 280 /// present) and consistent with the debug_info section DIEs. 281 /// 282 /// \param AccelSection section containing the acceleration table 283 /// \param StrData string section 284 /// 285 /// \returns The number of errors occurred during verification 286 unsigned verifyDebugNames(const DWARFSection &AccelSection, 287 const DataExtractor &StrData); 288 289 public: 290 DWARFVerifier(raw_ostream &S, DWARFContext &D, 291 DIDumpOptions DumpOpts = DIDumpOptions::getForSingleDIE()); 292 293 /// Verify the information in any of the following sections, if available: 294 /// .debug_abbrev, debug_abbrev.dwo 295 /// 296 /// Any errors are reported to the stream that was this object was 297 /// constructed with. 298 /// 299 /// \returns true if .debug_abbrev and .debug_abbrev.dwo verify successfully, 300 /// false otherwise. 301 bool handleDebugAbbrev(); 302 303 /// Verify the information in the .debug_info and .debug_types sections. 304 /// 305 /// Any errors are reported to the stream that this object was 306 /// constructed with. 307 /// 308 /// \returns true if all sections verify successfully, false otherwise. 309 bool handleDebugInfo(); 310 311 /// Verify the information in the .debug_line section. 312 /// 313 /// Any errors are reported to the stream that was this object was 314 /// constructed with. 315 /// 316 /// \returns true if the .debug_line verifies successfully, false otherwise. 317 bool handleDebugLine(); 318 319 /// Verify the information in accelerator tables, if they exist. 320 /// 321 /// Any errors are reported to the stream that was this object was 322 /// constructed with. 323 /// 324 /// \returns true if the existing Apple-style accelerator tables verify 325 /// successfully, false otherwise. 326 bool handleAccelTables(); 327 }; 328 329 static inline bool operator<(const DWARFVerifier::DieRangeInfo &LHS, 330 const DWARFVerifier::DieRangeInfo &RHS) { 331 return std::tie(LHS.Ranges, LHS.Die) < std::tie(RHS.Ranges, RHS.Die); 332 } 333 334 } // end namespace llvm 335 336 #endif // LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H 337