1 //===-- ObjectFileELF.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 "ObjectFileELF.h"
10
11 #include <algorithm>
12 #include <cassert>
13 #include <optional>
14 #include <unordered_map>
15
16 #include "lldb/Core/Module.h"
17 #include "lldb/Core/ModuleSpec.h"
18 #include "lldb/Core/PluginManager.h"
19 #include "lldb/Core/Progress.h"
20 #include "lldb/Core/Section.h"
21 #include "lldb/Host/FileSystem.h"
22 #include "lldb/Host/LZMA.h"
23 #include "lldb/Symbol/DWARFCallFrameInfo.h"
24 #include "lldb/Symbol/SymbolContext.h"
25 #include "lldb/Target/SectionLoadList.h"
26 #include "lldb/Target/Target.h"
27 #include "lldb/Utility/ArchSpec.h"
28 #include "lldb/Utility/DataBufferHeap.h"
29 #include "lldb/Utility/FileSpecList.h"
30 #include "lldb/Utility/LLDBLog.h"
31 #include "lldb/Utility/Log.h"
32 #include "lldb/Utility/RangeMap.h"
33 #include "lldb/Utility/Status.h"
34 #include "lldb/Utility/Stream.h"
35 #include "lldb/Utility/Timer.h"
36 #include "llvm/ADT/IntervalMap.h"
37 #include "llvm/ADT/PointerUnion.h"
38 #include "llvm/ADT/StringRef.h"
39 #include "llvm/BinaryFormat/ELF.h"
40 #include "llvm/Object/Decompressor.h"
41 #include "llvm/Support/ARMBuildAttributes.h"
42 #include "llvm/Support/CRC.h"
43 #include "llvm/Support/FormatVariadic.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/MemoryBuffer.h"
46 #include "llvm/Support/MipsABIFlags.h"
47
48 #define CASE_AND_STREAM(s, def, width) \
49 case def: \
50 s->Printf("%-*s", width, #def); \
51 break;
52
53 using namespace lldb;
54 using namespace lldb_private;
55 using namespace elf;
56 using namespace llvm::ELF;
57
58 LLDB_PLUGIN_DEFINE(ObjectFileELF)
59
60 // ELF note owner definitions
61 static const char *const LLDB_NT_OWNER_FREEBSD = "FreeBSD";
62 static const char *const LLDB_NT_OWNER_GNU = "GNU";
63 static const char *const LLDB_NT_OWNER_NETBSD = "NetBSD";
64 static const char *const LLDB_NT_OWNER_NETBSDCORE = "NetBSD-CORE";
65 static const char *const LLDB_NT_OWNER_OPENBSD = "OpenBSD";
66 static const char *const LLDB_NT_OWNER_ANDROID = "Android";
67 static const char *const LLDB_NT_OWNER_CORE = "CORE";
68 static const char *const LLDB_NT_OWNER_LINUX = "LINUX";
69
70 // ELF note type definitions
71 static const elf_word LLDB_NT_FREEBSD_ABI_TAG = 0x01;
72 static const elf_word LLDB_NT_FREEBSD_ABI_SIZE = 4;
73
74 static const elf_word LLDB_NT_GNU_ABI_TAG = 0x01;
75 static const elf_word LLDB_NT_GNU_ABI_SIZE = 16;
76
77 static const elf_word LLDB_NT_GNU_BUILD_ID_TAG = 0x03;
78
79 static const elf_word LLDB_NT_NETBSD_IDENT_TAG = 1;
80 static const elf_word LLDB_NT_NETBSD_IDENT_DESCSZ = 4;
81 static const elf_word LLDB_NT_NETBSD_IDENT_NAMESZ = 7;
82 static const elf_word LLDB_NT_NETBSD_PROCINFO = 1;
83
84 // GNU ABI note OS constants
85 static const elf_word LLDB_NT_GNU_ABI_OS_LINUX = 0x00;
86 static const elf_word LLDB_NT_GNU_ABI_OS_HURD = 0x01;
87 static const elf_word LLDB_NT_GNU_ABI_OS_SOLARIS = 0x02;
88
89 namespace {
90
91 //===----------------------------------------------------------------------===//
92 /// \class ELFRelocation
93 /// Generic wrapper for ELFRel and ELFRela.
94 ///
95 /// This helper class allows us to parse both ELFRel and ELFRela relocation
96 /// entries in a generic manner.
97 class ELFRelocation {
98 public:
99 /// Constructs an ELFRelocation entry with a personality as given by @p
100 /// type.
101 ///
102 /// \param type Either DT_REL or DT_RELA. Any other value is invalid.
103 ELFRelocation(unsigned type);
104
105 ~ELFRelocation();
106
107 bool Parse(const lldb_private::DataExtractor &data, lldb::offset_t *offset);
108
109 static unsigned RelocType32(const ELFRelocation &rel);
110
111 static unsigned RelocType64(const ELFRelocation &rel);
112
113 static unsigned RelocSymbol32(const ELFRelocation &rel);
114
115 static unsigned RelocSymbol64(const ELFRelocation &rel);
116
117 static elf_addr RelocOffset32(const ELFRelocation &rel);
118
119 static elf_addr RelocOffset64(const ELFRelocation &rel);
120
121 static elf_sxword RelocAddend32(const ELFRelocation &rel);
122
123 static elf_sxword RelocAddend64(const ELFRelocation &rel);
124
IsRela()125 bool IsRela() { return (reloc.is<ELFRela *>()); }
126
127 private:
128 typedef llvm::PointerUnion<ELFRel *, ELFRela *> RelocUnion;
129
130 RelocUnion reloc;
131 };
132 } // end anonymous namespace
133
ELFRelocation(unsigned type)134 ELFRelocation::ELFRelocation(unsigned type) {
135 if (type == DT_REL || type == SHT_REL)
136 reloc = new ELFRel();
137 else if (type == DT_RELA || type == SHT_RELA)
138 reloc = new ELFRela();
139 else {
140 assert(false && "unexpected relocation type");
141 reloc = static_cast<ELFRel *>(nullptr);
142 }
143 }
144
~ELFRelocation()145 ELFRelocation::~ELFRelocation() {
146 if (reloc.is<ELFRel *>())
147 delete reloc.get<ELFRel *>();
148 else
149 delete reloc.get<ELFRela *>();
150 }
151
Parse(const lldb_private::DataExtractor & data,lldb::offset_t * offset)152 bool ELFRelocation::Parse(const lldb_private::DataExtractor &data,
153 lldb::offset_t *offset) {
154 if (reloc.is<ELFRel *>())
155 return reloc.get<ELFRel *>()->Parse(data, offset);
156 else
157 return reloc.get<ELFRela *>()->Parse(data, offset);
158 }
159
RelocType32(const ELFRelocation & rel)160 unsigned ELFRelocation::RelocType32(const ELFRelocation &rel) {
161 if (rel.reloc.is<ELFRel *>())
162 return ELFRel::RelocType32(*rel.reloc.get<ELFRel *>());
163 else
164 return ELFRela::RelocType32(*rel.reloc.get<ELFRela *>());
165 }
166
RelocType64(const ELFRelocation & rel)167 unsigned ELFRelocation::RelocType64(const ELFRelocation &rel) {
168 if (rel.reloc.is<ELFRel *>())
169 return ELFRel::RelocType64(*rel.reloc.get<ELFRel *>());
170 else
171 return ELFRela::RelocType64(*rel.reloc.get<ELFRela *>());
172 }
173
RelocSymbol32(const ELFRelocation & rel)174 unsigned ELFRelocation::RelocSymbol32(const ELFRelocation &rel) {
175 if (rel.reloc.is<ELFRel *>())
176 return ELFRel::RelocSymbol32(*rel.reloc.get<ELFRel *>());
177 else
178 return ELFRela::RelocSymbol32(*rel.reloc.get<ELFRela *>());
179 }
180
RelocSymbol64(const ELFRelocation & rel)181 unsigned ELFRelocation::RelocSymbol64(const ELFRelocation &rel) {
182 if (rel.reloc.is<ELFRel *>())
183 return ELFRel::RelocSymbol64(*rel.reloc.get<ELFRel *>());
184 else
185 return ELFRela::RelocSymbol64(*rel.reloc.get<ELFRela *>());
186 }
187
RelocOffset32(const ELFRelocation & rel)188 elf_addr ELFRelocation::RelocOffset32(const ELFRelocation &rel) {
189 if (rel.reloc.is<ELFRel *>())
190 return rel.reloc.get<ELFRel *>()->r_offset;
191 else
192 return rel.reloc.get<ELFRela *>()->r_offset;
193 }
194
RelocOffset64(const ELFRelocation & rel)195 elf_addr ELFRelocation::RelocOffset64(const ELFRelocation &rel) {
196 if (rel.reloc.is<ELFRel *>())
197 return rel.reloc.get<ELFRel *>()->r_offset;
198 else
199 return rel.reloc.get<ELFRela *>()->r_offset;
200 }
201
RelocAddend32(const ELFRelocation & rel)202 elf_sxword ELFRelocation::RelocAddend32(const ELFRelocation &rel) {
203 if (rel.reloc.is<ELFRel *>())
204 return 0;
205 else
206 return rel.reloc.get<ELFRela *>()->r_addend;
207 }
208
RelocAddend64(const ELFRelocation & rel)209 elf_sxword ELFRelocation::RelocAddend64(const ELFRelocation &rel) {
210 if (rel.reloc.is<ELFRel *>())
211 return 0;
212 else
213 return rel.reloc.get<ELFRela *>()->r_addend;
214 }
215
SegmentID(size_t PHdrIndex)216 static user_id_t SegmentID(size_t PHdrIndex) {
217 return ~user_id_t(PHdrIndex);
218 }
219
Parse(const DataExtractor & data,lldb::offset_t * offset)220 bool ELFNote::Parse(const DataExtractor &data, lldb::offset_t *offset) {
221 // Read all fields.
222 if (data.GetU32(offset, &n_namesz, 3) == nullptr)
223 return false;
224
225 // The name field is required to be nul-terminated, and n_namesz includes the
226 // terminating nul in observed implementations (contrary to the ELF-64 spec).
227 // A special case is needed for cores generated by some older Linux versions,
228 // which write a note named "CORE" without a nul terminator and n_namesz = 4.
229 if (n_namesz == 4) {
230 char buf[4];
231 if (data.ExtractBytes(*offset, 4, data.GetByteOrder(), buf) != 4)
232 return false;
233 if (strncmp(buf, "CORE", 4) == 0) {
234 n_name = "CORE";
235 *offset += 4;
236 return true;
237 }
238 }
239
240 const char *cstr = data.GetCStr(offset, llvm::alignTo(n_namesz, 4));
241 if (cstr == nullptr) {
242 Log *log = GetLog(LLDBLog::Symbols);
243 LLDB_LOGF(log, "Failed to parse note name lacking nul terminator");
244
245 return false;
246 }
247 n_name = cstr;
248 return true;
249 }
250
mipsVariantFromElfFlags(const elf::ELFHeader & header)251 static uint32_t mipsVariantFromElfFlags (const elf::ELFHeader &header) {
252 const uint32_t mips_arch = header.e_flags & llvm::ELF::EF_MIPS_ARCH;
253 uint32_t endian = header.e_ident[EI_DATA];
254 uint32_t arch_variant = ArchSpec::eMIPSSubType_unknown;
255 uint32_t fileclass = header.e_ident[EI_CLASS];
256
257 // If there aren't any elf flags available (e.g core elf file) then return
258 // default
259 // 32 or 64 bit arch (without any architecture revision) based on object file's class.
260 if (header.e_type == ET_CORE) {
261 switch (fileclass) {
262 case llvm::ELF::ELFCLASS32:
263 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32el
264 : ArchSpec::eMIPSSubType_mips32;
265 case llvm::ELF::ELFCLASS64:
266 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64el
267 : ArchSpec::eMIPSSubType_mips64;
268 default:
269 return arch_variant;
270 }
271 }
272
273 switch (mips_arch) {
274 case llvm::ELF::EF_MIPS_ARCH_1:
275 case llvm::ELF::EF_MIPS_ARCH_2:
276 case llvm::ELF::EF_MIPS_ARCH_32:
277 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32el
278 : ArchSpec::eMIPSSubType_mips32;
279 case llvm::ELF::EF_MIPS_ARCH_32R2:
280 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32r2el
281 : ArchSpec::eMIPSSubType_mips32r2;
282 case llvm::ELF::EF_MIPS_ARCH_32R6:
283 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips32r6el
284 : ArchSpec::eMIPSSubType_mips32r6;
285 case llvm::ELF::EF_MIPS_ARCH_3:
286 case llvm::ELF::EF_MIPS_ARCH_4:
287 case llvm::ELF::EF_MIPS_ARCH_5:
288 case llvm::ELF::EF_MIPS_ARCH_64:
289 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64el
290 : ArchSpec::eMIPSSubType_mips64;
291 case llvm::ELF::EF_MIPS_ARCH_64R2:
292 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64r2el
293 : ArchSpec::eMIPSSubType_mips64r2;
294 case llvm::ELF::EF_MIPS_ARCH_64R6:
295 return (endian == ELFDATA2LSB) ? ArchSpec::eMIPSSubType_mips64r6el
296 : ArchSpec::eMIPSSubType_mips64r6;
297 default:
298 break;
299 }
300
301 return arch_variant;
302 }
303
riscvVariantFromElfFlags(const elf::ELFHeader & header)304 static uint32_t riscvVariantFromElfFlags(const elf::ELFHeader &header) {
305 uint32_t fileclass = header.e_ident[EI_CLASS];
306 switch (fileclass) {
307 case llvm::ELF::ELFCLASS32:
308 return ArchSpec::eRISCVSubType_riscv32;
309 case llvm::ELF::ELFCLASS64:
310 return ArchSpec::eRISCVSubType_riscv64;
311 default:
312 return ArchSpec::eRISCVSubType_unknown;
313 }
314 }
315
ppc64VariantFromElfFlags(const elf::ELFHeader & header)316 static uint32_t ppc64VariantFromElfFlags(const elf::ELFHeader &header) {
317 uint32_t endian = header.e_ident[EI_DATA];
318 if (endian == ELFDATA2LSB)
319 return ArchSpec::eCore_ppc64le_generic;
320 else
321 return ArchSpec::eCore_ppc64_generic;
322 }
323
loongarchVariantFromElfFlags(const elf::ELFHeader & header)324 static uint32_t loongarchVariantFromElfFlags(const elf::ELFHeader &header) {
325 uint32_t fileclass = header.e_ident[EI_CLASS];
326 switch (fileclass) {
327 case llvm::ELF::ELFCLASS32:
328 return ArchSpec::eLoongArchSubType_loongarch32;
329 case llvm::ELF::ELFCLASS64:
330 return ArchSpec::eLoongArchSubType_loongarch64;
331 default:
332 return ArchSpec::eLoongArchSubType_unknown;
333 }
334 }
335
subTypeFromElfHeader(const elf::ELFHeader & header)336 static uint32_t subTypeFromElfHeader(const elf::ELFHeader &header) {
337 if (header.e_machine == llvm::ELF::EM_MIPS)
338 return mipsVariantFromElfFlags(header);
339 else if (header.e_machine == llvm::ELF::EM_PPC64)
340 return ppc64VariantFromElfFlags(header);
341 else if (header.e_machine == llvm::ELF::EM_RISCV)
342 return riscvVariantFromElfFlags(header);
343 else if (header.e_machine == llvm::ELF::EM_LOONGARCH)
344 return loongarchVariantFromElfFlags(header);
345
346 return LLDB_INVALID_CPUTYPE;
347 }
348
349 char ObjectFileELF::ID;
350
351 // Arbitrary constant used as UUID prefix for core files.
352 const uint32_t ObjectFileELF::g_core_uuid_magic(0xE210C);
353
354 // Static methods.
Initialize()355 void ObjectFileELF::Initialize() {
356 PluginManager::RegisterPlugin(GetPluginNameStatic(),
357 GetPluginDescriptionStatic(), CreateInstance,
358 CreateMemoryInstance, GetModuleSpecifications);
359 }
360
Terminate()361 void ObjectFileELF::Terminate() {
362 PluginManager::UnregisterPlugin(CreateInstance);
363 }
364
CreateInstance(const lldb::ModuleSP & module_sp,DataBufferSP data_sp,lldb::offset_t data_offset,const lldb_private::FileSpec * file,lldb::offset_t file_offset,lldb::offset_t length)365 ObjectFile *ObjectFileELF::CreateInstance(const lldb::ModuleSP &module_sp,
366 DataBufferSP data_sp,
367 lldb::offset_t data_offset,
368 const lldb_private::FileSpec *file,
369 lldb::offset_t file_offset,
370 lldb::offset_t length) {
371 bool mapped_writable = false;
372 if (!data_sp) {
373 data_sp = MapFileDataWritable(*file, length, file_offset);
374 if (!data_sp)
375 return nullptr;
376 data_offset = 0;
377 mapped_writable = true;
378 }
379
380 assert(data_sp);
381
382 if (data_sp->GetByteSize() <= (llvm::ELF::EI_NIDENT + data_offset))
383 return nullptr;
384
385 const uint8_t *magic = data_sp->GetBytes() + data_offset;
386 if (!ELFHeader::MagicBytesMatch(magic))
387 return nullptr;
388
389 // Update the data to contain the entire file if it doesn't already
390 if (data_sp->GetByteSize() < length) {
391 data_sp = MapFileDataWritable(*file, length, file_offset);
392 if (!data_sp)
393 return nullptr;
394 data_offset = 0;
395 mapped_writable = true;
396 magic = data_sp->GetBytes();
397 }
398
399 // If we didn't map the data as writable take ownership of the buffer.
400 if (!mapped_writable) {
401 data_sp = std::make_shared<DataBufferHeap>(data_sp->GetBytes(),
402 data_sp->GetByteSize());
403 data_offset = 0;
404 magic = data_sp->GetBytes();
405 }
406
407 unsigned address_size = ELFHeader::AddressSizeInBytes(magic);
408 if (address_size == 4 || address_size == 8) {
409 std::unique_ptr<ObjectFileELF> objfile_up(new ObjectFileELF(
410 module_sp, data_sp, data_offset, file, file_offset, length));
411 ArchSpec spec = objfile_up->GetArchitecture();
412 if (spec && objfile_up->SetModulesArchitecture(spec))
413 return objfile_up.release();
414 }
415
416 return nullptr;
417 }
418
CreateMemoryInstance(const lldb::ModuleSP & module_sp,WritableDataBufferSP data_sp,const lldb::ProcessSP & process_sp,lldb::addr_t header_addr)419 ObjectFile *ObjectFileELF::CreateMemoryInstance(
420 const lldb::ModuleSP &module_sp, WritableDataBufferSP data_sp,
421 const lldb::ProcessSP &process_sp, lldb::addr_t header_addr) {
422 if (data_sp && data_sp->GetByteSize() > (llvm::ELF::EI_NIDENT)) {
423 const uint8_t *magic = data_sp->GetBytes();
424 if (ELFHeader::MagicBytesMatch(magic)) {
425 unsigned address_size = ELFHeader::AddressSizeInBytes(magic);
426 if (address_size == 4 || address_size == 8) {
427 std::unique_ptr<ObjectFileELF> objfile_up(
428 new ObjectFileELF(module_sp, data_sp, process_sp, header_addr));
429 ArchSpec spec = objfile_up->GetArchitecture();
430 if (spec && objfile_up->SetModulesArchitecture(spec))
431 return objfile_up.release();
432 }
433 }
434 }
435 return nullptr;
436 }
437
MagicBytesMatch(DataBufferSP & data_sp,lldb::addr_t data_offset,lldb::addr_t data_length)438 bool ObjectFileELF::MagicBytesMatch(DataBufferSP &data_sp,
439 lldb::addr_t data_offset,
440 lldb::addr_t data_length) {
441 if (data_sp &&
442 data_sp->GetByteSize() > (llvm::ELF::EI_NIDENT + data_offset)) {
443 const uint8_t *magic = data_sp->GetBytes() + data_offset;
444 return ELFHeader::MagicBytesMatch(magic);
445 }
446 return false;
447 }
448
calc_crc32(uint32_t init,const DataExtractor & data)449 static uint32_t calc_crc32(uint32_t init, const DataExtractor &data) {
450 return llvm::crc32(init,
451 llvm::ArrayRef(data.GetDataStart(), data.GetByteSize()));
452 }
453
CalculateELFNotesSegmentsCRC32(const ProgramHeaderColl & program_headers,DataExtractor & object_data)454 uint32_t ObjectFileELF::CalculateELFNotesSegmentsCRC32(
455 const ProgramHeaderColl &program_headers, DataExtractor &object_data) {
456
457 uint32_t core_notes_crc = 0;
458
459 for (const ELFProgramHeader &H : program_headers) {
460 if (H.p_type == llvm::ELF::PT_NOTE) {
461 const elf_off ph_offset = H.p_offset;
462 const size_t ph_size = H.p_filesz;
463
464 DataExtractor segment_data;
465 if (segment_data.SetData(object_data, ph_offset, ph_size) != ph_size) {
466 // The ELF program header contained incorrect data, probably corefile
467 // is incomplete or corrupted.
468 break;
469 }
470
471 core_notes_crc = calc_crc32(core_notes_crc, segment_data);
472 }
473 }
474
475 return core_notes_crc;
476 }
477
OSABIAsCString(unsigned char osabi_byte)478 static const char *OSABIAsCString(unsigned char osabi_byte) {
479 #define _MAKE_OSABI_CASE(x) \
480 case x: \
481 return #x
482 switch (osabi_byte) {
483 _MAKE_OSABI_CASE(ELFOSABI_NONE);
484 _MAKE_OSABI_CASE(ELFOSABI_HPUX);
485 _MAKE_OSABI_CASE(ELFOSABI_NETBSD);
486 _MAKE_OSABI_CASE(ELFOSABI_GNU);
487 _MAKE_OSABI_CASE(ELFOSABI_HURD);
488 _MAKE_OSABI_CASE(ELFOSABI_SOLARIS);
489 _MAKE_OSABI_CASE(ELFOSABI_AIX);
490 _MAKE_OSABI_CASE(ELFOSABI_IRIX);
491 _MAKE_OSABI_CASE(ELFOSABI_FREEBSD);
492 _MAKE_OSABI_CASE(ELFOSABI_TRU64);
493 _MAKE_OSABI_CASE(ELFOSABI_MODESTO);
494 _MAKE_OSABI_CASE(ELFOSABI_OPENBSD);
495 _MAKE_OSABI_CASE(ELFOSABI_OPENVMS);
496 _MAKE_OSABI_CASE(ELFOSABI_NSK);
497 _MAKE_OSABI_CASE(ELFOSABI_AROS);
498 _MAKE_OSABI_CASE(ELFOSABI_FENIXOS);
499 _MAKE_OSABI_CASE(ELFOSABI_C6000_ELFABI);
500 _MAKE_OSABI_CASE(ELFOSABI_C6000_LINUX);
501 _MAKE_OSABI_CASE(ELFOSABI_ARM);
502 _MAKE_OSABI_CASE(ELFOSABI_STANDALONE);
503 default:
504 return "<unknown-osabi>";
505 }
506 #undef _MAKE_OSABI_CASE
507 }
508
509 //
510 // WARNING : This function is being deprecated
511 // It's functionality has moved to ArchSpec::SetArchitecture This function is
512 // only being kept to validate the move.
513 //
514 // TODO : Remove this function
GetOsFromOSABI(unsigned char osabi_byte,llvm::Triple::OSType & ostype)515 static bool GetOsFromOSABI(unsigned char osabi_byte,
516 llvm::Triple::OSType &ostype) {
517 switch (osabi_byte) {
518 case ELFOSABI_AIX:
519 ostype = llvm::Triple::OSType::AIX;
520 break;
521 case ELFOSABI_FREEBSD:
522 ostype = llvm::Triple::OSType::FreeBSD;
523 break;
524 case ELFOSABI_GNU:
525 ostype = llvm::Triple::OSType::Linux;
526 break;
527 case ELFOSABI_NETBSD:
528 ostype = llvm::Triple::OSType::NetBSD;
529 break;
530 case ELFOSABI_OPENBSD:
531 ostype = llvm::Triple::OSType::OpenBSD;
532 break;
533 case ELFOSABI_SOLARIS:
534 ostype = llvm::Triple::OSType::Solaris;
535 break;
536 default:
537 ostype = llvm::Triple::OSType::UnknownOS;
538 }
539 return ostype != llvm::Triple::OSType::UnknownOS;
540 }
541
GetModuleSpecifications(const lldb_private::FileSpec & file,lldb::DataBufferSP & data_sp,lldb::offset_t data_offset,lldb::offset_t file_offset,lldb::offset_t length,lldb_private::ModuleSpecList & specs)542 size_t ObjectFileELF::GetModuleSpecifications(
543 const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
544 lldb::offset_t data_offset, lldb::offset_t file_offset,
545 lldb::offset_t length, lldb_private::ModuleSpecList &specs) {
546 Log *log = GetLog(LLDBLog::Modules);
547
548 const size_t initial_count = specs.GetSize();
549
550 if (ObjectFileELF::MagicBytesMatch(data_sp, 0, data_sp->GetByteSize())) {
551 DataExtractor data;
552 data.SetData(data_sp);
553 elf::ELFHeader header;
554 lldb::offset_t header_offset = data_offset;
555 if (header.Parse(data, &header_offset)) {
556 if (data_sp) {
557 ModuleSpec spec(file);
558 // In Android API level 23 and above, bionic dynamic linker is able to
559 // load .so file directly from zip file. In that case, .so file is
560 // page aligned and uncompressed, and this module spec should retain the
561 // .so file offset and file size to pass through the information from
562 // lldb-server to LLDB. For normal file, file_offset should be 0,
563 // length should be the size of the file.
564 spec.SetObjectOffset(file_offset);
565 spec.SetObjectSize(length);
566
567 const uint32_t sub_type = subTypeFromElfHeader(header);
568 spec.GetArchitecture().SetArchitecture(
569 eArchTypeELF, header.e_machine, sub_type, header.e_ident[EI_OSABI]);
570
571 if (spec.GetArchitecture().IsValid()) {
572 llvm::Triple::OSType ostype;
573 llvm::Triple::VendorType vendor;
574 llvm::Triple::OSType spec_ostype =
575 spec.GetArchitecture().GetTriple().getOS();
576
577 LLDB_LOGF(log, "ObjectFileELF::%s file '%s' module OSABI: %s",
578 __FUNCTION__, file.GetPath().c_str(),
579 OSABIAsCString(header.e_ident[EI_OSABI]));
580
581 // SetArchitecture should have set the vendor to unknown
582 vendor = spec.GetArchitecture().GetTriple().getVendor();
583 assert(vendor == llvm::Triple::UnknownVendor);
584 UNUSED_IF_ASSERT_DISABLED(vendor);
585
586 //
587 // Validate it is ok to remove GetOsFromOSABI
588 GetOsFromOSABI(header.e_ident[EI_OSABI], ostype);
589 assert(spec_ostype == ostype);
590 if (spec_ostype != llvm::Triple::OSType::UnknownOS) {
591 LLDB_LOGF(log,
592 "ObjectFileELF::%s file '%s' set ELF module OS type "
593 "from ELF header OSABI.",
594 __FUNCTION__, file.GetPath().c_str());
595 }
596
597 // When ELF file does not contain GNU build ID, the later code will
598 // calculate CRC32 with this data_sp file_offset and length. It is
599 // important for Android zip .so file, which is a slice of a file,
600 // to not access the outside of the file slice range.
601 if (data_sp->GetByteSize() < length)
602 data_sp = MapFileData(file, length, file_offset);
603 if (data_sp)
604 data.SetData(data_sp);
605 // In case there is header extension in the section #0, the header we
606 // parsed above could have sentinel values for e_phnum, e_shnum, and
607 // e_shstrndx. In this case we need to reparse the header with a
608 // bigger data source to get the actual values.
609 if (header.HasHeaderExtension()) {
610 lldb::offset_t header_offset = data_offset;
611 header.Parse(data, &header_offset);
612 }
613
614 uint32_t gnu_debuglink_crc = 0;
615 std::string gnu_debuglink_file;
616 SectionHeaderColl section_headers;
617 lldb_private::UUID &uuid = spec.GetUUID();
618
619 GetSectionHeaderInfo(section_headers, data, header, uuid,
620 gnu_debuglink_file, gnu_debuglink_crc,
621 spec.GetArchitecture());
622
623 llvm::Triple &spec_triple = spec.GetArchitecture().GetTriple();
624
625 LLDB_LOGF(log,
626 "ObjectFileELF::%s file '%s' module set to triple: %s "
627 "(architecture %s)",
628 __FUNCTION__, file.GetPath().c_str(),
629 spec_triple.getTriple().c_str(),
630 spec.GetArchitecture().GetArchitectureName());
631
632 if (!uuid.IsValid()) {
633 uint32_t core_notes_crc = 0;
634
635 if (!gnu_debuglink_crc) {
636 LLDB_SCOPED_TIMERF(
637 "Calculating module crc32 %s with size %" PRIu64 " KiB",
638 file.GetFilename().AsCString(),
639 (length - file_offset) / 1024);
640
641 // For core files - which usually don't happen to have a
642 // gnu_debuglink, and are pretty bulky - calculating whole
643 // contents crc32 would be too much of luxury. Thus we will need
644 // to fallback to something simpler.
645 if (header.e_type == llvm::ELF::ET_CORE) {
646 ProgramHeaderColl program_headers;
647 GetProgramHeaderInfo(program_headers, data, header);
648
649 core_notes_crc =
650 CalculateELFNotesSegmentsCRC32(program_headers, data);
651 } else {
652 gnu_debuglink_crc = calc_crc32(0, data);
653 }
654 }
655 using u32le = llvm::support::ulittle32_t;
656 if (gnu_debuglink_crc) {
657 // Use 4 bytes of crc from the .gnu_debuglink section.
658 u32le data(gnu_debuglink_crc);
659 uuid = UUID(&data, sizeof(data));
660 } else if (core_notes_crc) {
661 // Use 8 bytes - first 4 bytes for *magic* prefix, mainly to make
662 // it look different form .gnu_debuglink crc followed by 4 bytes
663 // of note segments crc.
664 u32le data[] = {u32le(g_core_uuid_magic), u32le(core_notes_crc)};
665 uuid = UUID(data, sizeof(data));
666 }
667 }
668
669 specs.Append(spec);
670 }
671 }
672 }
673 }
674
675 return specs.GetSize() - initial_count;
676 }
677
678 // ObjectFile protocol
679
ObjectFileELF(const lldb::ModuleSP & module_sp,DataBufferSP data_sp,lldb::offset_t data_offset,const FileSpec * file,lldb::offset_t file_offset,lldb::offset_t length)680 ObjectFileELF::ObjectFileELF(const lldb::ModuleSP &module_sp,
681 DataBufferSP data_sp, lldb::offset_t data_offset,
682 const FileSpec *file, lldb::offset_t file_offset,
683 lldb::offset_t length)
684 : ObjectFile(module_sp, file, file_offset, length, data_sp, data_offset) {
685 if (file)
686 m_file = *file;
687 }
688
ObjectFileELF(const lldb::ModuleSP & module_sp,DataBufferSP header_data_sp,const lldb::ProcessSP & process_sp,addr_t header_addr)689 ObjectFileELF::ObjectFileELF(const lldb::ModuleSP &module_sp,
690 DataBufferSP header_data_sp,
691 const lldb::ProcessSP &process_sp,
692 addr_t header_addr)
693 : ObjectFile(module_sp, process_sp, header_addr, header_data_sp) {}
694
IsExecutable() const695 bool ObjectFileELF::IsExecutable() const {
696 return ((m_header.e_type & ET_EXEC) != 0) || (m_header.e_entry != 0);
697 }
698
SetLoadAddress(Target & target,lldb::addr_t value,bool value_is_offset)699 bool ObjectFileELF::SetLoadAddress(Target &target, lldb::addr_t value,
700 bool value_is_offset) {
701 ModuleSP module_sp = GetModule();
702 if (module_sp) {
703 size_t num_loaded_sections = 0;
704 SectionList *section_list = GetSectionList();
705 if (section_list) {
706 if (!value_is_offset) {
707 addr_t base = GetBaseAddress().GetFileAddress();
708 if (base == LLDB_INVALID_ADDRESS)
709 return false;
710 value -= base;
711 }
712
713 const size_t num_sections = section_list->GetSize();
714 size_t sect_idx = 0;
715
716 for (sect_idx = 0; sect_idx < num_sections; ++sect_idx) {
717 // Iterate through the object file sections to find all of the sections
718 // that have SHF_ALLOC in their flag bits.
719 SectionSP section_sp(section_list->GetSectionAtIndex(sect_idx));
720
721 // PT_TLS segments can have the same p_vaddr and p_paddr as other
722 // PT_LOAD segments so we shouldn't load them. If we do load them, then
723 // the SectionLoadList will incorrectly fill in the instance variable
724 // SectionLoadList::m_addr_to_sect with the same address as a PT_LOAD
725 // segment and we won't be able to resolve addresses in the PT_LOAD
726 // segment whose p_vaddr entry matches that of the PT_TLS. Any variables
727 // that appear in the PT_TLS segments get resolved by the DWARF
728 // expressions. If this ever changes we will need to fix all object
729 // file plug-ins, but until then, we don't want PT_TLS segments to
730 // remove the entry from SectionLoadList::m_addr_to_sect when we call
731 // SetSectionLoadAddress() below.
732 if (section_sp->IsThreadSpecific())
733 continue;
734 if (section_sp->Test(SHF_ALLOC) ||
735 section_sp->GetType() == eSectionTypeContainer) {
736 lldb::addr_t load_addr = section_sp->GetFileAddress();
737 // We don't want to update the load address of a section with type
738 // eSectionTypeAbsoluteAddress as they already have the absolute load
739 // address already specified
740 if (section_sp->GetType() != eSectionTypeAbsoluteAddress)
741 load_addr += value;
742
743 // On 32-bit systems the load address have to fit into 4 bytes. The
744 // rest of the bytes are the overflow from the addition.
745 if (GetAddressByteSize() == 4)
746 load_addr &= 0xFFFFFFFF;
747
748 if (target.GetSectionLoadList().SetSectionLoadAddress(section_sp,
749 load_addr))
750 ++num_loaded_sections;
751 }
752 }
753 return num_loaded_sections > 0;
754 }
755 }
756 return false;
757 }
758
GetByteOrder() const759 ByteOrder ObjectFileELF::GetByteOrder() const {
760 if (m_header.e_ident[EI_DATA] == ELFDATA2MSB)
761 return eByteOrderBig;
762 if (m_header.e_ident[EI_DATA] == ELFDATA2LSB)
763 return eByteOrderLittle;
764 return eByteOrderInvalid;
765 }
766
GetAddressByteSize() const767 uint32_t ObjectFileELF::GetAddressByteSize() const {
768 return m_data.GetAddressByteSize();
769 }
770
GetAddressClass(addr_t file_addr)771 AddressClass ObjectFileELF::GetAddressClass(addr_t file_addr) {
772 Symtab *symtab = GetSymtab();
773 if (!symtab)
774 return AddressClass::eUnknown;
775
776 // The address class is determined based on the symtab. Ask it from the
777 // object file what contains the symtab information.
778 ObjectFile *symtab_objfile = symtab->GetObjectFile();
779 if (symtab_objfile != nullptr && symtab_objfile != this)
780 return symtab_objfile->GetAddressClass(file_addr);
781
782 auto res = ObjectFile::GetAddressClass(file_addr);
783 if (res != AddressClass::eCode)
784 return res;
785
786 auto ub = m_address_class_map.upper_bound(file_addr);
787 if (ub == m_address_class_map.begin()) {
788 // No entry in the address class map before the address. Return default
789 // address class for an address in a code section.
790 return AddressClass::eCode;
791 }
792
793 // Move iterator to the address class entry preceding address
794 --ub;
795
796 return ub->second;
797 }
798
SectionIndex(const SectionHeaderCollIter & I)799 size_t ObjectFileELF::SectionIndex(const SectionHeaderCollIter &I) {
800 return std::distance(m_section_headers.begin(), I);
801 }
802
SectionIndex(const SectionHeaderCollConstIter & I) const803 size_t ObjectFileELF::SectionIndex(const SectionHeaderCollConstIter &I) const {
804 return std::distance(m_section_headers.begin(), I);
805 }
806
ParseHeader()807 bool ObjectFileELF::ParseHeader() {
808 lldb::offset_t offset = 0;
809 return m_header.Parse(m_data, &offset);
810 }
811
GetUUID()812 UUID ObjectFileELF::GetUUID() {
813 // Need to parse the section list to get the UUIDs, so make sure that's been
814 // done.
815 if (!ParseSectionHeaders() && GetType() != ObjectFile::eTypeCoreFile)
816 return UUID();
817
818 if (!m_uuid) {
819 using u32le = llvm::support::ulittle32_t;
820 if (GetType() == ObjectFile::eTypeCoreFile) {
821 uint32_t core_notes_crc = 0;
822
823 if (!ParseProgramHeaders())
824 return UUID();
825
826 core_notes_crc =
827 CalculateELFNotesSegmentsCRC32(m_program_headers, m_data);
828
829 if (core_notes_crc) {
830 // Use 8 bytes - first 4 bytes for *magic* prefix, mainly to make it
831 // look different form .gnu_debuglink crc - followed by 4 bytes of note
832 // segments crc.
833 u32le data[] = {u32le(g_core_uuid_magic), u32le(core_notes_crc)};
834 m_uuid = UUID(data, sizeof(data));
835 }
836 } else {
837 if (!m_gnu_debuglink_crc)
838 m_gnu_debuglink_crc = calc_crc32(0, m_data);
839 if (m_gnu_debuglink_crc) {
840 // Use 4 bytes of crc from the .gnu_debuglink section.
841 u32le data(m_gnu_debuglink_crc);
842 m_uuid = UUID(&data, sizeof(data));
843 }
844 }
845 }
846
847 return m_uuid;
848 }
849
GetDebugLink()850 std::optional<FileSpec> ObjectFileELF::GetDebugLink() {
851 if (m_gnu_debuglink_file.empty())
852 return std::nullopt;
853 return FileSpec(m_gnu_debuglink_file);
854 }
855
GetDependentModules(FileSpecList & files)856 uint32_t ObjectFileELF::GetDependentModules(FileSpecList &files) {
857 size_t num_modules = ParseDependentModules();
858 uint32_t num_specs = 0;
859
860 for (unsigned i = 0; i < num_modules; ++i) {
861 if (files.AppendIfUnique(m_filespec_up->GetFileSpecAtIndex(i)))
862 num_specs++;
863 }
864
865 return num_specs;
866 }
867
GetImageInfoAddress(Target * target)868 Address ObjectFileELF::GetImageInfoAddress(Target *target) {
869 if (!ParseDynamicSymbols())
870 return Address();
871
872 SectionList *section_list = GetSectionList();
873 if (!section_list)
874 return Address();
875
876 // Find the SHT_DYNAMIC (.dynamic) section.
877 SectionSP dynsym_section_sp(
878 section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true));
879 if (!dynsym_section_sp)
880 return Address();
881 assert(dynsym_section_sp->GetObjectFile() == this);
882
883 user_id_t dynsym_id = dynsym_section_sp->GetID();
884 const ELFSectionHeaderInfo *dynsym_hdr = GetSectionHeaderByIndex(dynsym_id);
885 if (!dynsym_hdr)
886 return Address();
887
888 for (size_t i = 0; i < m_dynamic_symbols.size(); ++i) {
889 ELFDynamic &symbol = m_dynamic_symbols[i];
890
891 if (symbol.d_tag == DT_DEBUG) {
892 // Compute the offset as the number of previous entries plus the size of
893 // d_tag.
894 addr_t offset = i * dynsym_hdr->sh_entsize + GetAddressByteSize();
895 return Address(dynsym_section_sp, offset);
896 }
897 // MIPS executables uses DT_MIPS_RLD_MAP_REL to support PIE. DT_MIPS_RLD_MAP
898 // exists in non-PIE.
899 else if ((symbol.d_tag == DT_MIPS_RLD_MAP ||
900 symbol.d_tag == DT_MIPS_RLD_MAP_REL) &&
901 target) {
902 addr_t offset = i * dynsym_hdr->sh_entsize + GetAddressByteSize();
903 addr_t dyn_base = dynsym_section_sp->GetLoadBaseAddress(target);
904 if (dyn_base == LLDB_INVALID_ADDRESS)
905 return Address();
906
907 Status error;
908 if (symbol.d_tag == DT_MIPS_RLD_MAP) {
909 // DT_MIPS_RLD_MAP tag stores an absolute address of the debug pointer.
910 Address addr;
911 if (target->ReadPointerFromMemory(dyn_base + offset, error, addr, true))
912 return addr;
913 }
914 if (symbol.d_tag == DT_MIPS_RLD_MAP_REL) {
915 // DT_MIPS_RLD_MAP_REL tag stores the offset to the debug pointer,
916 // relative to the address of the tag.
917 uint64_t rel_offset;
918 rel_offset = target->ReadUnsignedIntegerFromMemory(
919 dyn_base + offset, GetAddressByteSize(), UINT64_MAX, error, true);
920 if (error.Success() && rel_offset != UINT64_MAX) {
921 Address addr;
922 addr_t debug_ptr_address =
923 dyn_base + (offset - GetAddressByteSize()) + rel_offset;
924 addr.SetOffset(debug_ptr_address);
925 return addr;
926 }
927 }
928 }
929 }
930
931 return Address();
932 }
933
GetEntryPointAddress()934 lldb_private::Address ObjectFileELF::GetEntryPointAddress() {
935 if (m_entry_point_address.IsValid())
936 return m_entry_point_address;
937
938 if (!ParseHeader() || !IsExecutable())
939 return m_entry_point_address;
940
941 SectionList *section_list = GetSectionList();
942 addr_t offset = m_header.e_entry;
943
944 if (!section_list)
945 m_entry_point_address.SetOffset(offset);
946 else
947 m_entry_point_address.ResolveAddressUsingFileSections(offset, section_list);
948 return m_entry_point_address;
949 }
950
GetBaseAddress()951 Address ObjectFileELF::GetBaseAddress() {
952 if (GetType() == ObjectFile::eTypeObjectFile) {
953 for (SectionHeaderCollIter I = std::next(m_section_headers.begin());
954 I != m_section_headers.end(); ++I) {
955 const ELFSectionHeaderInfo &header = *I;
956 if (header.sh_flags & SHF_ALLOC)
957 return Address(GetSectionList()->FindSectionByID(SectionIndex(I)), 0);
958 }
959 return LLDB_INVALID_ADDRESS;
960 }
961
962 for (const auto &EnumPHdr : llvm::enumerate(ProgramHeaders())) {
963 const ELFProgramHeader &H = EnumPHdr.value();
964 if (H.p_type != PT_LOAD)
965 continue;
966
967 return Address(
968 GetSectionList()->FindSectionByID(SegmentID(EnumPHdr.index())), 0);
969 }
970 return LLDB_INVALID_ADDRESS;
971 }
972
973 // ParseDependentModules
ParseDependentModules()974 size_t ObjectFileELF::ParseDependentModules() {
975 if (m_filespec_up)
976 return m_filespec_up->GetSize();
977
978 m_filespec_up = std::make_unique<FileSpecList>();
979
980 if (!ParseSectionHeaders())
981 return 0;
982
983 SectionList *section_list = GetSectionList();
984 if (!section_list)
985 return 0;
986
987 // Find the SHT_DYNAMIC section.
988 Section *dynsym =
989 section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true)
990 .get();
991 if (!dynsym)
992 return 0;
993 assert(dynsym->GetObjectFile() == this);
994
995 const ELFSectionHeaderInfo *header = GetSectionHeaderByIndex(dynsym->GetID());
996 if (!header)
997 return 0;
998 // sh_link: section header index of string table used by entries in the
999 // section.
1000 Section *dynstr = section_list->FindSectionByID(header->sh_link).get();
1001 if (!dynstr)
1002 return 0;
1003
1004 DataExtractor dynsym_data;
1005 DataExtractor dynstr_data;
1006 if (ReadSectionData(dynsym, dynsym_data) &&
1007 ReadSectionData(dynstr, dynstr_data)) {
1008 ELFDynamic symbol;
1009 const lldb::offset_t section_size = dynsym_data.GetByteSize();
1010 lldb::offset_t offset = 0;
1011
1012 // The only type of entries we are concerned with are tagged DT_NEEDED,
1013 // yielding the name of a required library.
1014 while (offset < section_size) {
1015 if (!symbol.Parse(dynsym_data, &offset))
1016 break;
1017
1018 if (symbol.d_tag != DT_NEEDED)
1019 continue;
1020
1021 uint32_t str_index = static_cast<uint32_t>(symbol.d_val);
1022 const char *lib_name = dynstr_data.PeekCStr(str_index);
1023 FileSpec file_spec(lib_name);
1024 FileSystem::Instance().Resolve(file_spec);
1025 m_filespec_up->Append(file_spec);
1026 }
1027 }
1028
1029 return m_filespec_up->GetSize();
1030 }
1031
1032 // GetProgramHeaderInfo
GetProgramHeaderInfo(ProgramHeaderColl & program_headers,DataExtractor & object_data,const ELFHeader & header)1033 size_t ObjectFileELF::GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
1034 DataExtractor &object_data,
1035 const ELFHeader &header) {
1036 // We have already parsed the program headers
1037 if (!program_headers.empty())
1038 return program_headers.size();
1039
1040 // If there are no program headers to read we are done.
1041 if (header.e_phnum == 0)
1042 return 0;
1043
1044 program_headers.resize(header.e_phnum);
1045 if (program_headers.size() != header.e_phnum)
1046 return 0;
1047
1048 const size_t ph_size = header.e_phnum * header.e_phentsize;
1049 const elf_off ph_offset = header.e_phoff;
1050 DataExtractor data;
1051 if (data.SetData(object_data, ph_offset, ph_size) != ph_size)
1052 return 0;
1053
1054 uint32_t idx;
1055 lldb::offset_t offset;
1056 for (idx = 0, offset = 0; idx < header.e_phnum; ++idx) {
1057 if (!program_headers[idx].Parse(data, &offset))
1058 break;
1059 }
1060
1061 if (idx < program_headers.size())
1062 program_headers.resize(idx);
1063
1064 return program_headers.size();
1065 }
1066
1067 // ParseProgramHeaders
ParseProgramHeaders()1068 bool ObjectFileELF::ParseProgramHeaders() {
1069 return GetProgramHeaderInfo(m_program_headers, m_data, m_header) != 0;
1070 }
1071
1072 lldb_private::Status
RefineModuleDetailsFromNote(lldb_private::DataExtractor & data,lldb_private::ArchSpec & arch_spec,lldb_private::UUID & uuid)1073 ObjectFileELF::RefineModuleDetailsFromNote(lldb_private::DataExtractor &data,
1074 lldb_private::ArchSpec &arch_spec,
1075 lldb_private::UUID &uuid) {
1076 Log *log = GetLog(LLDBLog::Modules);
1077 Status error;
1078
1079 lldb::offset_t offset = 0;
1080
1081 while (true) {
1082 // Parse the note header. If this fails, bail out.
1083 const lldb::offset_t note_offset = offset;
1084 ELFNote note = ELFNote();
1085 if (!note.Parse(data, &offset)) {
1086 // We're done.
1087 return error;
1088 }
1089
1090 LLDB_LOGF(log, "ObjectFileELF::%s parsing note name='%s', type=%" PRIu32,
1091 __FUNCTION__, note.n_name.c_str(), note.n_type);
1092
1093 // Process FreeBSD ELF notes.
1094 if ((note.n_name == LLDB_NT_OWNER_FREEBSD) &&
1095 (note.n_type == LLDB_NT_FREEBSD_ABI_TAG) &&
1096 (note.n_descsz == LLDB_NT_FREEBSD_ABI_SIZE)) {
1097 // Pull out the min version info.
1098 uint32_t version_info;
1099 if (data.GetU32(&offset, &version_info, 1) == nullptr) {
1100 error.SetErrorString("failed to read FreeBSD ABI note payload");
1101 return error;
1102 }
1103
1104 // Convert the version info into a major/minor number.
1105 const uint32_t version_major = version_info / 100000;
1106 const uint32_t version_minor = (version_info / 1000) % 100;
1107
1108 char os_name[32];
1109 snprintf(os_name, sizeof(os_name), "freebsd%" PRIu32 ".%" PRIu32,
1110 version_major, version_minor);
1111
1112 // Set the elf OS version to FreeBSD. Also clear the vendor.
1113 arch_spec.GetTriple().setOSName(os_name);
1114 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1115
1116 LLDB_LOGF(log,
1117 "ObjectFileELF::%s detected FreeBSD %" PRIu32 ".%" PRIu32
1118 ".%" PRIu32,
1119 __FUNCTION__, version_major, version_minor,
1120 static_cast<uint32_t>(version_info % 1000));
1121 }
1122 // Process GNU ELF notes.
1123 else if (note.n_name == LLDB_NT_OWNER_GNU) {
1124 switch (note.n_type) {
1125 case LLDB_NT_GNU_ABI_TAG:
1126 if (note.n_descsz == LLDB_NT_GNU_ABI_SIZE) {
1127 // Pull out the min OS version supporting the ABI.
1128 uint32_t version_info[4];
1129 if (data.GetU32(&offset, &version_info[0], note.n_descsz / 4) ==
1130 nullptr) {
1131 error.SetErrorString("failed to read GNU ABI note payload");
1132 return error;
1133 }
1134
1135 // Set the OS per the OS field.
1136 switch (version_info[0]) {
1137 case LLDB_NT_GNU_ABI_OS_LINUX:
1138 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1139 arch_spec.GetTriple().setVendor(
1140 llvm::Triple::VendorType::UnknownVendor);
1141 LLDB_LOGF(log,
1142 "ObjectFileELF::%s detected Linux, min version %" PRIu32
1143 ".%" PRIu32 ".%" PRIu32,
1144 __FUNCTION__, version_info[1], version_info[2],
1145 version_info[3]);
1146 // FIXME we have the minimal version number, we could be propagating
1147 // that. version_info[1] = OS Major, version_info[2] = OS Minor,
1148 // version_info[3] = Revision.
1149 break;
1150 case LLDB_NT_GNU_ABI_OS_HURD:
1151 arch_spec.GetTriple().setOS(llvm::Triple::OSType::UnknownOS);
1152 arch_spec.GetTriple().setVendor(
1153 llvm::Triple::VendorType::UnknownVendor);
1154 LLDB_LOGF(log,
1155 "ObjectFileELF::%s detected Hurd (unsupported), min "
1156 "version %" PRIu32 ".%" PRIu32 ".%" PRIu32,
1157 __FUNCTION__, version_info[1], version_info[2],
1158 version_info[3]);
1159 break;
1160 case LLDB_NT_GNU_ABI_OS_SOLARIS:
1161 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Solaris);
1162 arch_spec.GetTriple().setVendor(
1163 llvm::Triple::VendorType::UnknownVendor);
1164 LLDB_LOGF(log,
1165 "ObjectFileELF::%s detected Solaris, min version %" PRIu32
1166 ".%" PRIu32 ".%" PRIu32,
1167 __FUNCTION__, version_info[1], version_info[2],
1168 version_info[3]);
1169 break;
1170 default:
1171 LLDB_LOGF(log,
1172 "ObjectFileELF::%s unrecognized OS in note, id %" PRIu32
1173 ", min version %" PRIu32 ".%" PRIu32 ".%" PRIu32,
1174 __FUNCTION__, version_info[0], version_info[1],
1175 version_info[2], version_info[3]);
1176 break;
1177 }
1178 }
1179 break;
1180
1181 case LLDB_NT_GNU_BUILD_ID_TAG:
1182 // Only bother processing this if we don't already have the uuid set.
1183 if (!uuid.IsValid()) {
1184 // 16 bytes is UUID|MD5, 20 bytes is SHA1. Other linkers may produce a
1185 // build-id of a different length. Accept it as long as it's at least
1186 // 4 bytes as it will be better than our own crc32.
1187 if (note.n_descsz >= 4) {
1188 if (const uint8_t *buf = data.PeekData(offset, note.n_descsz)) {
1189 // Save the build id as the UUID for the module.
1190 uuid = UUID(buf, note.n_descsz);
1191 } else {
1192 error.SetErrorString("failed to read GNU_BUILD_ID note payload");
1193 return error;
1194 }
1195 }
1196 }
1197 break;
1198 }
1199 if (arch_spec.IsMIPS() &&
1200 arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS)
1201 // The note.n_name == LLDB_NT_OWNER_GNU is valid for Linux platform
1202 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1203 }
1204 // Process NetBSD ELF executables and shared libraries
1205 else if ((note.n_name == LLDB_NT_OWNER_NETBSD) &&
1206 (note.n_type == LLDB_NT_NETBSD_IDENT_TAG) &&
1207 (note.n_descsz == LLDB_NT_NETBSD_IDENT_DESCSZ) &&
1208 (note.n_namesz == LLDB_NT_NETBSD_IDENT_NAMESZ)) {
1209 // Pull out the version info.
1210 uint32_t version_info;
1211 if (data.GetU32(&offset, &version_info, 1) == nullptr) {
1212 error.SetErrorString("failed to read NetBSD ABI note payload");
1213 return error;
1214 }
1215 // Convert the version info into a major/minor/patch number.
1216 // #define __NetBSD_Version__ MMmmrrpp00
1217 //
1218 // M = major version
1219 // m = minor version; a minor number of 99 indicates current.
1220 // r = 0 (since NetBSD 3.0 not used)
1221 // p = patchlevel
1222 const uint32_t version_major = version_info / 100000000;
1223 const uint32_t version_minor = (version_info % 100000000) / 1000000;
1224 const uint32_t version_patch = (version_info % 10000) / 100;
1225 // Set the elf OS version to NetBSD. Also clear the vendor.
1226 arch_spec.GetTriple().setOSName(
1227 llvm::formatv("netbsd{0}.{1}.{2}", version_major, version_minor,
1228 version_patch).str());
1229 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1230 }
1231 // Process NetBSD ELF core(5) notes
1232 else if ((note.n_name == LLDB_NT_OWNER_NETBSDCORE) &&
1233 (note.n_type == LLDB_NT_NETBSD_PROCINFO)) {
1234 // Set the elf OS version to NetBSD. Also clear the vendor.
1235 arch_spec.GetTriple().setOS(llvm::Triple::OSType::NetBSD);
1236 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1237 }
1238 // Process OpenBSD ELF notes.
1239 else if (note.n_name == LLDB_NT_OWNER_OPENBSD) {
1240 // Set the elf OS version to OpenBSD. Also clear the vendor.
1241 arch_spec.GetTriple().setOS(llvm::Triple::OSType::OpenBSD);
1242 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1243 } else if (note.n_name == LLDB_NT_OWNER_ANDROID) {
1244 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1245 arch_spec.GetTriple().setEnvironment(
1246 llvm::Triple::EnvironmentType::Android);
1247 } else if (note.n_name == LLDB_NT_OWNER_LINUX) {
1248 // This is sometimes found in core files and usually contains extended
1249 // register info
1250 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1251 } else if (note.n_name == LLDB_NT_OWNER_CORE) {
1252 // Parse the NT_FILE to look for stuff in paths to shared libraries
1253 // The contents look like this in a 64 bit ELF core file:
1254 //
1255 // count = 0x000000000000000a (10)
1256 // page_size = 0x0000000000001000 (4096)
1257 // Index start end file_ofs path
1258 // ===== ------------------ ------------------ ------------------ -------------------------------------
1259 // [ 0] 0x0000000000401000 0x0000000000000000 /tmp/a.out
1260 // [ 1] 0x0000000000600000 0x0000000000601000 0x0000000000000000 /tmp/a.out
1261 // [ 2] 0x0000000000601000 0x0000000000602000 0x0000000000000001 /tmp/a.out
1262 // [ 3] 0x00007fa79c9ed000 0x00007fa79cba8000 0x0000000000000000 /lib/x86_64-linux-gnu/libc-2.19.so
1263 // [ 4] 0x00007fa79cba8000 0x00007fa79cda7000 0x00000000000001bb /lib/x86_64-linux-gnu/libc-2.19.so
1264 // [ 5] 0x00007fa79cda7000 0x00007fa79cdab000 0x00000000000001ba /lib/x86_64-linux-gnu/libc-2.19.so
1265 // [ 6] 0x00007fa79cdab000 0x00007fa79cdad000 0x00000000000001be /lib/x86_64-linux-gnu/libc-2.19.so
1266 // [ 7] 0x00007fa79cdb2000 0x00007fa79cdd5000 0x0000000000000000 /lib/x86_64-linux-gnu/ld-2.19.so
1267 // [ 8] 0x00007fa79cfd4000 0x00007fa79cfd5000 0x0000000000000022 /lib/x86_64-linux-gnu/ld-2.19.so
1268 // [ 9] 0x00007fa79cfd5000 0x00007fa79cfd6000 0x0000000000000023 /lib/x86_64-linux-gnu/ld-2.19.so
1269 //
1270 // In the 32 bit ELFs the count, page_size, start, end, file_ofs are
1271 // uint32_t.
1272 //
1273 // For reference: see readelf source code (in binutils).
1274 if (note.n_type == NT_FILE) {
1275 uint64_t count = data.GetAddress(&offset);
1276 const char *cstr;
1277 data.GetAddress(&offset); // Skip page size
1278 offset += count * 3 *
1279 data.GetAddressByteSize(); // Skip all start/end/file_ofs
1280 for (size_t i = 0; i < count; ++i) {
1281 cstr = data.GetCStr(&offset);
1282 if (cstr == nullptr) {
1283 error.SetErrorStringWithFormat("ObjectFileELF::%s trying to read "
1284 "at an offset after the end "
1285 "(GetCStr returned nullptr)",
1286 __FUNCTION__);
1287 return error;
1288 }
1289 llvm::StringRef path(cstr);
1290 if (path.contains("/lib/x86_64-linux-gnu") || path.contains("/lib/i386-linux-gnu")) {
1291 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1292 break;
1293 }
1294 }
1295 if (arch_spec.IsMIPS() &&
1296 arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS)
1297 // In case of MIPSR6, the LLDB_NT_OWNER_GNU note is missing for some
1298 // cases (e.g. compile with -nostdlib) Hence set OS to Linux
1299 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1300 }
1301 }
1302
1303 // Calculate the offset of the next note just in case "offset" has been
1304 // used to poke at the contents of the note data
1305 offset = note_offset + note.GetByteSize();
1306 }
1307
1308 return error;
1309 }
1310
ParseARMAttributes(DataExtractor & data,uint64_t length,ArchSpec & arch_spec)1311 void ObjectFileELF::ParseARMAttributes(DataExtractor &data, uint64_t length,
1312 ArchSpec &arch_spec) {
1313 lldb::offset_t Offset = 0;
1314
1315 uint8_t FormatVersion = data.GetU8(&Offset);
1316 if (FormatVersion != llvm::ELFAttrs::Format_Version)
1317 return;
1318
1319 Offset = Offset + sizeof(uint32_t); // Section Length
1320 llvm::StringRef VendorName = data.GetCStr(&Offset);
1321
1322 if (VendorName != "aeabi")
1323 return;
1324
1325 if (arch_spec.GetTriple().getEnvironment() ==
1326 llvm::Triple::UnknownEnvironment)
1327 arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
1328
1329 while (Offset < length) {
1330 uint8_t Tag = data.GetU8(&Offset);
1331 uint32_t Size = data.GetU32(&Offset);
1332
1333 if (Tag != llvm::ARMBuildAttrs::File || Size == 0)
1334 continue;
1335
1336 while (Offset < length) {
1337 uint64_t Tag = data.GetULEB128(&Offset);
1338 switch (Tag) {
1339 default:
1340 if (Tag < 32)
1341 data.GetULEB128(&Offset);
1342 else if (Tag % 2 == 0)
1343 data.GetULEB128(&Offset);
1344 else
1345 data.GetCStr(&Offset);
1346
1347 break;
1348
1349 case llvm::ARMBuildAttrs::CPU_raw_name:
1350 case llvm::ARMBuildAttrs::CPU_name:
1351 data.GetCStr(&Offset);
1352
1353 break;
1354
1355 case llvm::ARMBuildAttrs::ABI_VFP_args: {
1356 uint64_t VFPArgs = data.GetULEB128(&Offset);
1357
1358 if (VFPArgs == llvm::ARMBuildAttrs::BaseAAPCS) {
1359 if (arch_spec.GetTriple().getEnvironment() ==
1360 llvm::Triple::UnknownEnvironment ||
1361 arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABIHF)
1362 arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
1363
1364 arch_spec.SetFlags(ArchSpec::eARM_abi_soft_float);
1365 } else if (VFPArgs == llvm::ARMBuildAttrs::HardFPAAPCS) {
1366 if (arch_spec.GetTriple().getEnvironment() ==
1367 llvm::Triple::UnknownEnvironment ||
1368 arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABI)
1369 arch_spec.GetTriple().setEnvironment(llvm::Triple::EABIHF);
1370
1371 arch_spec.SetFlags(ArchSpec::eARM_abi_hard_float);
1372 }
1373
1374 break;
1375 }
1376 }
1377 }
1378 }
1379 }
1380
1381 // GetSectionHeaderInfo
GetSectionHeaderInfo(SectionHeaderColl & section_headers,DataExtractor & object_data,const elf::ELFHeader & header,lldb_private::UUID & uuid,std::string & gnu_debuglink_file,uint32_t & gnu_debuglink_crc,ArchSpec & arch_spec)1382 size_t ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl §ion_headers,
1383 DataExtractor &object_data,
1384 const elf::ELFHeader &header,
1385 lldb_private::UUID &uuid,
1386 std::string &gnu_debuglink_file,
1387 uint32_t &gnu_debuglink_crc,
1388 ArchSpec &arch_spec) {
1389 // Don't reparse the section headers if we already did that.
1390 if (!section_headers.empty())
1391 return section_headers.size();
1392
1393 // Only initialize the arch_spec to okay defaults if they're not already set.
1394 // We'll refine this with note data as we parse the notes.
1395 if (arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS) {
1396 llvm::Triple::OSType ostype;
1397 llvm::Triple::OSType spec_ostype;
1398 const uint32_t sub_type = subTypeFromElfHeader(header);
1399 arch_spec.SetArchitecture(eArchTypeELF, header.e_machine, sub_type,
1400 header.e_ident[EI_OSABI]);
1401
1402 // Validate if it is ok to remove GetOsFromOSABI. Note, that now the OS is
1403 // determined based on EI_OSABI flag and the info extracted from ELF notes
1404 // (see RefineModuleDetailsFromNote). However in some cases that still
1405 // might be not enough: for example a shared library might not have any
1406 // notes at all and have EI_OSABI flag set to System V, as result the OS
1407 // will be set to UnknownOS.
1408 GetOsFromOSABI(header.e_ident[EI_OSABI], ostype);
1409 spec_ostype = arch_spec.GetTriple().getOS();
1410 assert(spec_ostype == ostype);
1411 UNUSED_IF_ASSERT_DISABLED(spec_ostype);
1412 }
1413
1414 if (arch_spec.GetMachine() == llvm::Triple::mips ||
1415 arch_spec.GetMachine() == llvm::Triple::mipsel ||
1416 arch_spec.GetMachine() == llvm::Triple::mips64 ||
1417 arch_spec.GetMachine() == llvm::Triple::mips64el) {
1418 switch (header.e_flags & llvm::ELF::EF_MIPS_ARCH_ASE) {
1419 case llvm::ELF::EF_MIPS_MICROMIPS:
1420 arch_spec.SetFlags(ArchSpec::eMIPSAse_micromips);
1421 break;
1422 case llvm::ELF::EF_MIPS_ARCH_ASE_M16:
1423 arch_spec.SetFlags(ArchSpec::eMIPSAse_mips16);
1424 break;
1425 case llvm::ELF::EF_MIPS_ARCH_ASE_MDMX:
1426 arch_spec.SetFlags(ArchSpec::eMIPSAse_mdmx);
1427 break;
1428 default:
1429 break;
1430 }
1431 }
1432
1433 if (arch_spec.GetMachine() == llvm::Triple::arm ||
1434 arch_spec.GetMachine() == llvm::Triple::thumb) {
1435 if (header.e_flags & llvm::ELF::EF_ARM_SOFT_FLOAT)
1436 arch_spec.SetFlags(ArchSpec::eARM_abi_soft_float);
1437 else if (header.e_flags & llvm::ELF::EF_ARM_VFP_FLOAT)
1438 arch_spec.SetFlags(ArchSpec::eARM_abi_hard_float);
1439 }
1440
1441 if (arch_spec.GetMachine() == llvm::Triple::riscv32 ||
1442 arch_spec.GetMachine() == llvm::Triple::riscv64) {
1443 uint32_t flags = arch_spec.GetFlags();
1444
1445 if (header.e_flags & llvm::ELF::EF_RISCV_RVC)
1446 flags |= ArchSpec::eRISCV_rvc;
1447 if (header.e_flags & llvm::ELF::EF_RISCV_RVE)
1448 flags |= ArchSpec::eRISCV_rve;
1449
1450 if ((header.e_flags & llvm::ELF::EF_RISCV_FLOAT_ABI_SINGLE) ==
1451 llvm::ELF::EF_RISCV_FLOAT_ABI_SINGLE)
1452 flags |= ArchSpec::eRISCV_float_abi_single;
1453 else if ((header.e_flags & llvm::ELF::EF_RISCV_FLOAT_ABI_DOUBLE) ==
1454 llvm::ELF::EF_RISCV_FLOAT_ABI_DOUBLE)
1455 flags |= ArchSpec::eRISCV_float_abi_double;
1456 else if ((header.e_flags & llvm::ELF::EF_RISCV_FLOAT_ABI_QUAD) ==
1457 llvm::ELF::EF_RISCV_FLOAT_ABI_QUAD)
1458 flags |= ArchSpec::eRISCV_float_abi_quad;
1459
1460 arch_spec.SetFlags(flags);
1461 }
1462
1463 // If there are no section headers we are done.
1464 if (header.e_shnum == 0)
1465 return 0;
1466
1467 Log *log = GetLog(LLDBLog::Modules);
1468
1469 section_headers.resize(header.e_shnum);
1470 if (section_headers.size() != header.e_shnum)
1471 return 0;
1472
1473 const size_t sh_size = header.e_shnum * header.e_shentsize;
1474 const elf_off sh_offset = header.e_shoff;
1475 DataExtractor sh_data;
1476 if (sh_data.SetData(object_data, sh_offset, sh_size) != sh_size)
1477 return 0;
1478
1479 uint32_t idx;
1480 lldb::offset_t offset;
1481 for (idx = 0, offset = 0; idx < header.e_shnum; ++idx) {
1482 if (!section_headers[idx].Parse(sh_data, &offset))
1483 break;
1484 }
1485 if (idx < section_headers.size())
1486 section_headers.resize(idx);
1487
1488 const unsigned strtab_idx = header.e_shstrndx;
1489 if (strtab_idx && strtab_idx < section_headers.size()) {
1490 const ELFSectionHeaderInfo &sheader = section_headers[strtab_idx];
1491 const size_t byte_size = sheader.sh_size;
1492 const Elf64_Off offset = sheader.sh_offset;
1493 lldb_private::DataExtractor shstr_data;
1494
1495 if (shstr_data.SetData(object_data, offset, byte_size) == byte_size) {
1496 for (SectionHeaderCollIter I = section_headers.begin();
1497 I != section_headers.end(); ++I) {
1498 static ConstString g_sect_name_gnu_debuglink(".gnu_debuglink");
1499 const ELFSectionHeaderInfo &sheader = *I;
1500 const uint64_t section_size =
1501 sheader.sh_type == SHT_NOBITS ? 0 : sheader.sh_size;
1502 ConstString name(shstr_data.PeekCStr(I->sh_name));
1503
1504 I->section_name = name;
1505
1506 if (arch_spec.IsMIPS()) {
1507 uint32_t arch_flags = arch_spec.GetFlags();
1508 DataExtractor data;
1509 if (sheader.sh_type == SHT_MIPS_ABIFLAGS) {
1510
1511 if (section_size && (data.SetData(object_data, sheader.sh_offset,
1512 section_size) == section_size)) {
1513 // MIPS ASE Mask is at offset 12 in MIPS.abiflags section
1514 lldb::offset_t offset = 12; // MIPS ABI Flags Version: 0
1515 arch_flags |= data.GetU32(&offset);
1516
1517 // The floating point ABI is at offset 7
1518 offset = 7;
1519 switch (data.GetU8(&offset)) {
1520 case llvm::Mips::Val_GNU_MIPS_ABI_FP_ANY:
1521 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_ANY;
1522 break;
1523 case llvm::Mips::Val_GNU_MIPS_ABI_FP_DOUBLE:
1524 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_DOUBLE;
1525 break;
1526 case llvm::Mips::Val_GNU_MIPS_ABI_FP_SINGLE:
1527 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_SINGLE;
1528 break;
1529 case llvm::Mips::Val_GNU_MIPS_ABI_FP_SOFT:
1530 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_SOFT;
1531 break;
1532 case llvm::Mips::Val_GNU_MIPS_ABI_FP_OLD_64:
1533 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_OLD_64;
1534 break;
1535 case llvm::Mips::Val_GNU_MIPS_ABI_FP_XX:
1536 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_XX;
1537 break;
1538 case llvm::Mips::Val_GNU_MIPS_ABI_FP_64:
1539 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_64;
1540 break;
1541 case llvm::Mips::Val_GNU_MIPS_ABI_FP_64A:
1542 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_64A;
1543 break;
1544 }
1545 }
1546 }
1547 // Settings appropriate ArchSpec ABI Flags
1548 switch (header.e_flags & llvm::ELF::EF_MIPS_ABI) {
1549 case llvm::ELF::EF_MIPS_ABI_O32:
1550 arch_flags |= lldb_private::ArchSpec::eMIPSABI_O32;
1551 break;
1552 case EF_MIPS_ABI_O64:
1553 arch_flags |= lldb_private::ArchSpec::eMIPSABI_O64;
1554 break;
1555 case EF_MIPS_ABI_EABI32:
1556 arch_flags |= lldb_private::ArchSpec::eMIPSABI_EABI32;
1557 break;
1558 case EF_MIPS_ABI_EABI64:
1559 arch_flags |= lldb_private::ArchSpec::eMIPSABI_EABI64;
1560 break;
1561 default:
1562 // ABI Mask doesn't cover N32 and N64 ABI.
1563 if (header.e_ident[EI_CLASS] == llvm::ELF::ELFCLASS64)
1564 arch_flags |= lldb_private::ArchSpec::eMIPSABI_N64;
1565 else if (header.e_flags & llvm::ELF::EF_MIPS_ABI2)
1566 arch_flags |= lldb_private::ArchSpec::eMIPSABI_N32;
1567 break;
1568 }
1569 arch_spec.SetFlags(arch_flags);
1570 }
1571
1572 if (arch_spec.GetMachine() == llvm::Triple::arm ||
1573 arch_spec.GetMachine() == llvm::Triple::thumb) {
1574 DataExtractor data;
1575
1576 if (sheader.sh_type == SHT_ARM_ATTRIBUTES && section_size != 0 &&
1577 data.SetData(object_data, sheader.sh_offset, section_size) == section_size)
1578 ParseARMAttributes(data, section_size, arch_spec);
1579 }
1580
1581 if (name == g_sect_name_gnu_debuglink) {
1582 DataExtractor data;
1583 if (section_size && (data.SetData(object_data, sheader.sh_offset,
1584 section_size) == section_size)) {
1585 lldb::offset_t gnu_debuglink_offset = 0;
1586 gnu_debuglink_file = data.GetCStr(&gnu_debuglink_offset);
1587 gnu_debuglink_offset = llvm::alignTo(gnu_debuglink_offset, 4);
1588 data.GetU32(&gnu_debuglink_offset, &gnu_debuglink_crc, 1);
1589 }
1590 }
1591
1592 // Process ELF note section entries.
1593 bool is_note_header = (sheader.sh_type == SHT_NOTE);
1594
1595 // The section header ".note.android.ident" is stored as a
1596 // PROGBITS type header but it is actually a note header.
1597 static ConstString g_sect_name_android_ident(".note.android.ident");
1598 if (!is_note_header && name == g_sect_name_android_ident)
1599 is_note_header = true;
1600
1601 if (is_note_header) {
1602 // Allow notes to refine module info.
1603 DataExtractor data;
1604 if (section_size && (data.SetData(object_data, sheader.sh_offset,
1605 section_size) == section_size)) {
1606 Status error = RefineModuleDetailsFromNote(data, arch_spec, uuid);
1607 if (error.Fail()) {
1608 LLDB_LOGF(log, "ObjectFileELF::%s ELF note processing failed: %s",
1609 __FUNCTION__, error.AsCString());
1610 }
1611 }
1612 }
1613 }
1614
1615 // Make any unknown triple components to be unspecified unknowns.
1616 if (arch_spec.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
1617 arch_spec.GetTriple().setVendorName(llvm::StringRef());
1618 if (arch_spec.GetTriple().getOS() == llvm::Triple::UnknownOS)
1619 arch_spec.GetTriple().setOSName(llvm::StringRef());
1620
1621 return section_headers.size();
1622 }
1623 }
1624
1625 section_headers.clear();
1626 return 0;
1627 }
1628
1629 llvm::StringRef
StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const1630 ObjectFileELF::StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const {
1631 size_t pos = symbol_name.find('@');
1632 return symbol_name.substr(0, pos);
1633 }
1634
1635 // ParseSectionHeaders
ParseSectionHeaders()1636 size_t ObjectFileELF::ParseSectionHeaders() {
1637 return GetSectionHeaderInfo(m_section_headers, m_data, m_header, m_uuid,
1638 m_gnu_debuglink_file, m_gnu_debuglink_crc,
1639 m_arch_spec);
1640 }
1641
1642 const ObjectFileELF::ELFSectionHeaderInfo *
GetSectionHeaderByIndex(lldb::user_id_t id)1643 ObjectFileELF::GetSectionHeaderByIndex(lldb::user_id_t id) {
1644 if (!ParseSectionHeaders())
1645 return nullptr;
1646
1647 if (id < m_section_headers.size())
1648 return &m_section_headers[id];
1649
1650 return nullptr;
1651 }
1652
GetSectionIndexByName(const char * name)1653 lldb::user_id_t ObjectFileELF::GetSectionIndexByName(const char *name) {
1654 if (!name || !name[0] || !ParseSectionHeaders())
1655 return 0;
1656 for (size_t i = 1; i < m_section_headers.size(); ++i)
1657 if (m_section_headers[i].section_name == ConstString(name))
1658 return i;
1659 return 0;
1660 }
1661
GetSectionTypeFromName(llvm::StringRef Name)1662 static SectionType GetSectionTypeFromName(llvm::StringRef Name) {
1663 if (Name.consume_front(".debug_")) {
1664 return llvm::StringSwitch<SectionType>(Name)
1665 .Case("abbrev", eSectionTypeDWARFDebugAbbrev)
1666 .Case("abbrev.dwo", eSectionTypeDWARFDebugAbbrevDwo)
1667 .Case("addr", eSectionTypeDWARFDebugAddr)
1668 .Case("aranges", eSectionTypeDWARFDebugAranges)
1669 .Case("cu_index", eSectionTypeDWARFDebugCuIndex)
1670 .Case("frame", eSectionTypeDWARFDebugFrame)
1671 .Case("info", eSectionTypeDWARFDebugInfo)
1672 .Case("info.dwo", eSectionTypeDWARFDebugInfoDwo)
1673 .Cases("line", "line.dwo", eSectionTypeDWARFDebugLine)
1674 .Cases("line_str", "line_str.dwo", eSectionTypeDWARFDebugLineStr)
1675 .Case("loc", eSectionTypeDWARFDebugLoc)
1676 .Case("loc.dwo", eSectionTypeDWARFDebugLocDwo)
1677 .Case("loclists", eSectionTypeDWARFDebugLocLists)
1678 .Case("loclists.dwo", eSectionTypeDWARFDebugLocListsDwo)
1679 .Case("macinfo", eSectionTypeDWARFDebugMacInfo)
1680 .Cases("macro", "macro.dwo", eSectionTypeDWARFDebugMacro)
1681 .Case("names", eSectionTypeDWARFDebugNames)
1682 .Case("pubnames", eSectionTypeDWARFDebugPubNames)
1683 .Case("pubtypes", eSectionTypeDWARFDebugPubTypes)
1684 .Case("ranges", eSectionTypeDWARFDebugRanges)
1685 .Case("rnglists", eSectionTypeDWARFDebugRngLists)
1686 .Case("rnglists.dwo", eSectionTypeDWARFDebugRngListsDwo)
1687 .Case("str", eSectionTypeDWARFDebugStr)
1688 .Case("str.dwo", eSectionTypeDWARFDebugStrDwo)
1689 .Case("str_offsets", eSectionTypeDWARFDebugStrOffsets)
1690 .Case("str_offsets.dwo", eSectionTypeDWARFDebugStrOffsetsDwo)
1691 .Case("tu_index", eSectionTypeDWARFDebugTuIndex)
1692 .Case("types", eSectionTypeDWARFDebugTypes)
1693 .Case("types.dwo", eSectionTypeDWARFDebugTypesDwo)
1694 .Default(eSectionTypeOther);
1695 }
1696 return llvm::StringSwitch<SectionType>(Name)
1697 .Case(".ARM.exidx", eSectionTypeARMexidx)
1698 .Case(".ARM.extab", eSectionTypeARMextab)
1699 .Case(".ctf", eSectionTypeDebug)
1700 .Cases(".data", ".tdata", eSectionTypeData)
1701 .Case(".eh_frame", eSectionTypeEHFrame)
1702 .Case(".gnu_debugaltlink", eSectionTypeDWARFGNUDebugAltLink)
1703 .Case(".gosymtab", eSectionTypeGoSymtab)
1704 .Case(".text", eSectionTypeCode)
1705 .Case(".swift_ast", eSectionTypeSwiftModules)
1706 .Default(eSectionTypeOther);
1707 }
1708
GetSectionType(const ELFSectionHeaderInfo & H) const1709 SectionType ObjectFileELF::GetSectionType(const ELFSectionHeaderInfo &H) const {
1710 switch (H.sh_type) {
1711 case SHT_PROGBITS:
1712 if (H.sh_flags & SHF_EXECINSTR)
1713 return eSectionTypeCode;
1714 break;
1715 case SHT_NOBITS:
1716 if (H.sh_flags & SHF_ALLOC)
1717 return eSectionTypeZeroFill;
1718 break;
1719 case SHT_SYMTAB:
1720 return eSectionTypeELFSymbolTable;
1721 case SHT_DYNSYM:
1722 return eSectionTypeELFDynamicSymbols;
1723 case SHT_RELA:
1724 case SHT_REL:
1725 return eSectionTypeELFRelocationEntries;
1726 case SHT_DYNAMIC:
1727 return eSectionTypeELFDynamicLinkInfo;
1728 }
1729 return GetSectionTypeFromName(H.section_name.GetStringRef());
1730 }
1731
GetTargetByteSize(SectionType Type,const ArchSpec & arch)1732 static uint32_t GetTargetByteSize(SectionType Type, const ArchSpec &arch) {
1733 switch (Type) {
1734 case eSectionTypeData:
1735 case eSectionTypeZeroFill:
1736 return arch.GetDataByteSize();
1737 case eSectionTypeCode:
1738 return arch.GetCodeByteSize();
1739 default:
1740 return 1;
1741 }
1742 }
1743
GetPermissions(const ELFSectionHeader & H)1744 static Permissions GetPermissions(const ELFSectionHeader &H) {
1745 Permissions Perm = Permissions(0);
1746 if (H.sh_flags & SHF_ALLOC)
1747 Perm |= ePermissionsReadable;
1748 if (H.sh_flags & SHF_WRITE)
1749 Perm |= ePermissionsWritable;
1750 if (H.sh_flags & SHF_EXECINSTR)
1751 Perm |= ePermissionsExecutable;
1752 return Perm;
1753 }
1754
GetPermissions(const ELFProgramHeader & H)1755 static Permissions GetPermissions(const ELFProgramHeader &H) {
1756 Permissions Perm = Permissions(0);
1757 if (H.p_flags & PF_R)
1758 Perm |= ePermissionsReadable;
1759 if (H.p_flags & PF_W)
1760 Perm |= ePermissionsWritable;
1761 if (H.p_flags & PF_X)
1762 Perm |= ePermissionsExecutable;
1763 return Perm;
1764 }
1765
1766 namespace {
1767
1768 using VMRange = lldb_private::Range<addr_t, addr_t>;
1769
1770 struct SectionAddressInfo {
1771 SectionSP Segment;
1772 VMRange Range;
1773 };
1774
1775 // (Unlinked) ELF object files usually have 0 for every section address, meaning
1776 // we need to compute synthetic addresses in order for "file addresses" from
1777 // different sections to not overlap. This class handles that logic.
1778 class VMAddressProvider {
1779 using VMMap = llvm::IntervalMap<addr_t, SectionSP, 4,
1780 llvm::IntervalMapHalfOpenInfo<addr_t>>;
1781
1782 ObjectFile::Type ObjectType;
1783 addr_t NextVMAddress = 0;
1784 VMMap::Allocator Alloc;
1785 VMMap Segments{Alloc};
1786 VMMap Sections{Alloc};
1787 lldb_private::Log *Log = GetLog(LLDBLog::Modules);
1788 size_t SegmentCount = 0;
1789 std::string SegmentName;
1790
GetVMRange(const ELFSectionHeader & H)1791 VMRange GetVMRange(const ELFSectionHeader &H) {
1792 addr_t Address = H.sh_addr;
1793 addr_t Size = H.sh_flags & SHF_ALLOC ? H.sh_size : 0;
1794
1795 // When this is a debug file for relocatable file, the address is all zero
1796 // and thus needs to use accumulate method
1797 if ((ObjectType == ObjectFile::Type::eTypeObjectFile ||
1798 (ObjectType == ObjectFile::Type::eTypeDebugInfo && H.sh_addr == 0)) &&
1799 Segments.empty() && (H.sh_flags & SHF_ALLOC)) {
1800 NextVMAddress =
1801 llvm::alignTo(NextVMAddress, std::max<addr_t>(H.sh_addralign, 1));
1802 Address = NextVMAddress;
1803 NextVMAddress += Size;
1804 }
1805 return VMRange(Address, Size);
1806 }
1807
1808 public:
VMAddressProvider(ObjectFile::Type Type,llvm::StringRef SegmentName)1809 VMAddressProvider(ObjectFile::Type Type, llvm::StringRef SegmentName)
1810 : ObjectType(Type), SegmentName(std::string(SegmentName)) {}
1811
GetNextSegmentName() const1812 std::string GetNextSegmentName() const {
1813 return llvm::formatv("{0}[{1}]", SegmentName, SegmentCount).str();
1814 }
1815
GetAddressInfo(const ELFProgramHeader & H)1816 std::optional<VMRange> GetAddressInfo(const ELFProgramHeader &H) {
1817 if (H.p_memsz == 0) {
1818 LLDB_LOG(Log, "Ignoring zero-sized {0} segment. Corrupt object file?",
1819 SegmentName);
1820 return std::nullopt;
1821 }
1822
1823 if (Segments.overlaps(H.p_vaddr, H.p_vaddr + H.p_memsz)) {
1824 LLDB_LOG(Log, "Ignoring overlapping {0} segment. Corrupt object file?",
1825 SegmentName);
1826 return std::nullopt;
1827 }
1828 return VMRange(H.p_vaddr, H.p_memsz);
1829 }
1830
GetAddressInfo(const ELFSectionHeader & H)1831 std::optional<SectionAddressInfo> GetAddressInfo(const ELFSectionHeader &H) {
1832 VMRange Range = GetVMRange(H);
1833 SectionSP Segment;
1834 auto It = Segments.find(Range.GetRangeBase());
1835 if ((H.sh_flags & SHF_ALLOC) && It.valid()) {
1836 addr_t MaxSize;
1837 if (It.start() <= Range.GetRangeBase()) {
1838 MaxSize = It.stop() - Range.GetRangeBase();
1839 Segment = *It;
1840 } else
1841 MaxSize = It.start() - Range.GetRangeBase();
1842 if (Range.GetByteSize() > MaxSize) {
1843 LLDB_LOG(Log, "Shortening section crossing segment boundaries. "
1844 "Corrupt object file?");
1845 Range.SetByteSize(MaxSize);
1846 }
1847 }
1848 if (Range.GetByteSize() > 0 &&
1849 Sections.overlaps(Range.GetRangeBase(), Range.GetRangeEnd())) {
1850 LLDB_LOG(Log, "Ignoring overlapping section. Corrupt object file?");
1851 return std::nullopt;
1852 }
1853 if (Segment)
1854 Range.Slide(-Segment->GetFileAddress());
1855 return SectionAddressInfo{Segment, Range};
1856 }
1857
AddSegment(const VMRange & Range,SectionSP Seg)1858 void AddSegment(const VMRange &Range, SectionSP Seg) {
1859 Segments.insert(Range.GetRangeBase(), Range.GetRangeEnd(), std::move(Seg));
1860 ++SegmentCount;
1861 }
1862
AddSection(SectionAddressInfo Info,SectionSP Sect)1863 void AddSection(SectionAddressInfo Info, SectionSP Sect) {
1864 if (Info.Range.GetByteSize() == 0)
1865 return;
1866 if (Info.Segment)
1867 Info.Range.Slide(Info.Segment->GetFileAddress());
1868 Sections.insert(Info.Range.GetRangeBase(), Info.Range.GetRangeEnd(),
1869 std::move(Sect));
1870 }
1871 };
1872 }
1873
1874 // We have to do this because ELF doesn't have section IDs, and also
1875 // doesn't require section names to be unique. (We use the section index
1876 // for section IDs, but that isn't guaranteed to be the same in separate
1877 // debug images.)
FindMatchingSection(const SectionList & section_list,SectionSP section)1878 static SectionSP FindMatchingSection(const SectionList §ion_list,
1879 SectionSP section) {
1880 SectionSP sect_sp;
1881
1882 addr_t vm_addr = section->GetFileAddress();
1883 ConstString name = section->GetName();
1884 offset_t byte_size = section->GetByteSize();
1885 bool thread_specific = section->IsThreadSpecific();
1886 uint32_t permissions = section->GetPermissions();
1887 uint32_t alignment = section->GetLog2Align();
1888
1889 for (auto sect : section_list) {
1890 if (sect->GetName() == name &&
1891 sect->IsThreadSpecific() == thread_specific &&
1892 sect->GetPermissions() == permissions &&
1893 sect->GetByteSize() == byte_size && sect->GetFileAddress() == vm_addr &&
1894 sect->GetLog2Align() == alignment) {
1895 sect_sp = sect;
1896 break;
1897 } else {
1898 sect_sp = FindMatchingSection(sect->GetChildren(), section);
1899 if (sect_sp)
1900 break;
1901 }
1902 }
1903
1904 return sect_sp;
1905 }
1906
CreateSections(SectionList & unified_section_list)1907 void ObjectFileELF::CreateSections(SectionList &unified_section_list) {
1908 if (m_sections_up)
1909 return;
1910
1911 m_sections_up = std::make_unique<SectionList>();
1912 VMAddressProvider regular_provider(GetType(), "PT_LOAD");
1913 VMAddressProvider tls_provider(GetType(), "PT_TLS");
1914
1915 for (const auto &EnumPHdr : llvm::enumerate(ProgramHeaders())) {
1916 const ELFProgramHeader &PHdr = EnumPHdr.value();
1917 if (PHdr.p_type != PT_LOAD && PHdr.p_type != PT_TLS)
1918 continue;
1919
1920 VMAddressProvider &provider =
1921 PHdr.p_type == PT_TLS ? tls_provider : regular_provider;
1922 auto InfoOr = provider.GetAddressInfo(PHdr);
1923 if (!InfoOr)
1924 continue;
1925
1926 uint32_t Log2Align = llvm::Log2_64(std::max<elf_xword>(PHdr.p_align, 1));
1927 SectionSP Segment = std::make_shared<Section>(
1928 GetModule(), this, SegmentID(EnumPHdr.index()),
1929 ConstString(provider.GetNextSegmentName()), eSectionTypeContainer,
1930 InfoOr->GetRangeBase(), InfoOr->GetByteSize(), PHdr.p_offset,
1931 PHdr.p_filesz, Log2Align, /*flags*/ 0);
1932 Segment->SetPermissions(GetPermissions(PHdr));
1933 Segment->SetIsThreadSpecific(PHdr.p_type == PT_TLS);
1934 m_sections_up->AddSection(Segment);
1935
1936 provider.AddSegment(*InfoOr, std::move(Segment));
1937 }
1938
1939 ParseSectionHeaders();
1940 if (m_section_headers.empty())
1941 return;
1942
1943 for (SectionHeaderCollIter I = std::next(m_section_headers.begin());
1944 I != m_section_headers.end(); ++I) {
1945 const ELFSectionHeaderInfo &header = *I;
1946
1947 ConstString &name = I->section_name;
1948 const uint64_t file_size =
1949 header.sh_type == SHT_NOBITS ? 0 : header.sh_size;
1950
1951 VMAddressProvider &provider =
1952 header.sh_flags & SHF_TLS ? tls_provider : regular_provider;
1953 auto InfoOr = provider.GetAddressInfo(header);
1954 if (!InfoOr)
1955 continue;
1956
1957 SectionType sect_type = GetSectionType(header);
1958
1959 const uint32_t target_bytes_size =
1960 GetTargetByteSize(sect_type, m_arch_spec);
1961
1962 elf::elf_xword log2align =
1963 (header.sh_addralign == 0) ? 0 : llvm::Log2_64(header.sh_addralign);
1964
1965 SectionSP section_sp(new Section(
1966 InfoOr->Segment, GetModule(), // Module to which this section belongs.
1967 this, // ObjectFile to which this section belongs and should
1968 // read section data from.
1969 SectionIndex(I), // Section ID.
1970 name, // Section name.
1971 sect_type, // Section type.
1972 InfoOr->Range.GetRangeBase(), // VM address.
1973 InfoOr->Range.GetByteSize(), // VM size in bytes of this section.
1974 header.sh_offset, // Offset of this section in the file.
1975 file_size, // Size of the section as found in the file.
1976 log2align, // Alignment of the section
1977 header.sh_flags, // Flags for this section.
1978 target_bytes_size)); // Number of host bytes per target byte
1979
1980 section_sp->SetPermissions(GetPermissions(header));
1981 section_sp->SetIsThreadSpecific(header.sh_flags & SHF_TLS);
1982 (InfoOr->Segment ? InfoOr->Segment->GetChildren() : *m_sections_up)
1983 .AddSection(section_sp);
1984 provider.AddSection(std::move(*InfoOr), std::move(section_sp));
1985 }
1986
1987 // For eTypeDebugInfo files, the Symbol Vendor will take care of updating the
1988 // unified section list.
1989 if (GetType() != eTypeDebugInfo)
1990 unified_section_list = *m_sections_up;
1991
1992 // If there's a .gnu_debugdata section, we'll try to read the .symtab that's
1993 // embedded in there and replace the one in the original object file (if any).
1994 // If there's none in the orignal object file, we add it to it.
1995 if (auto gdd_obj_file = GetGnuDebugDataObjectFile()) {
1996 if (auto gdd_objfile_section_list = gdd_obj_file->GetSectionList()) {
1997 if (SectionSP symtab_section_sp =
1998 gdd_objfile_section_list->FindSectionByType(
1999 eSectionTypeELFSymbolTable, true)) {
2000 SectionSP module_section_sp = unified_section_list.FindSectionByType(
2001 eSectionTypeELFSymbolTable, true);
2002 if (module_section_sp)
2003 unified_section_list.ReplaceSection(module_section_sp->GetID(),
2004 symtab_section_sp);
2005 else
2006 unified_section_list.AddSection(symtab_section_sp);
2007 }
2008 }
2009 }
2010 }
2011
GetGnuDebugDataObjectFile()2012 std::shared_ptr<ObjectFileELF> ObjectFileELF::GetGnuDebugDataObjectFile() {
2013 if (m_gnu_debug_data_object_file != nullptr)
2014 return m_gnu_debug_data_object_file;
2015
2016 SectionSP section =
2017 GetSectionList()->FindSectionByName(ConstString(".gnu_debugdata"));
2018 if (!section)
2019 return nullptr;
2020
2021 if (!lldb_private::lzma::isAvailable()) {
2022 GetModule()->ReportWarning(
2023 "No LZMA support found for reading .gnu_debugdata section");
2024 return nullptr;
2025 }
2026
2027 // Uncompress the data
2028 DataExtractor data;
2029 section->GetSectionData(data);
2030 llvm::SmallVector<uint8_t, 0> uncompressedData;
2031 auto err = lldb_private::lzma::uncompress(data.GetData(), uncompressedData);
2032 if (err) {
2033 GetModule()->ReportWarning(
2034 "An error occurred while decompression the section {0}: {1}",
2035 section->GetName().AsCString(), llvm::toString(std::move(err)).c_str());
2036 return nullptr;
2037 }
2038
2039 // Construct ObjectFileELF object from decompressed buffer
2040 DataBufferSP gdd_data_buf(
2041 new DataBufferHeap(uncompressedData.data(), uncompressedData.size()));
2042 auto fspec = GetFileSpec().CopyByAppendingPathComponent(
2043 llvm::StringRef("gnu_debugdata"));
2044 m_gnu_debug_data_object_file.reset(new ObjectFileELF(
2045 GetModule(), gdd_data_buf, 0, &fspec, 0, gdd_data_buf->GetByteSize()));
2046
2047 // This line is essential; otherwise a breakpoint can be set but not hit.
2048 m_gnu_debug_data_object_file->SetType(ObjectFile::eTypeDebugInfo);
2049
2050 ArchSpec spec = m_gnu_debug_data_object_file->GetArchitecture();
2051 if (spec && m_gnu_debug_data_object_file->SetModulesArchitecture(spec))
2052 return m_gnu_debug_data_object_file;
2053
2054 return nullptr;
2055 }
2056
2057 // Find the arm/aarch64 mapping symbol character in the given symbol name.
2058 // Mapping symbols have the form of "$<char>[.<any>]*". Additionally we
2059 // recognize cases when the mapping symbol prefixed by an arbitrary string
2060 // because if a symbol prefix added to each symbol in the object file with
2061 // objcopy then the mapping symbols are also prefixed.
FindArmAarch64MappingSymbol(const char * symbol_name)2062 static char FindArmAarch64MappingSymbol(const char *symbol_name) {
2063 if (!symbol_name)
2064 return '\0';
2065
2066 const char *dollar_pos = ::strchr(symbol_name, '$');
2067 if (!dollar_pos || dollar_pos[1] == '\0')
2068 return '\0';
2069
2070 if (dollar_pos[2] == '\0' || dollar_pos[2] == '.')
2071 return dollar_pos[1];
2072 return '\0';
2073 }
2074
2075 #define STO_MIPS_ISA (3 << 6)
2076 #define STO_MICROMIPS (2 << 6)
2077 #define IS_MICROMIPS(ST_OTHER) (((ST_OTHER)&STO_MIPS_ISA) == STO_MICROMIPS)
2078
2079 // private
2080 std::pair<unsigned, ObjectFileELF::FileAddressToAddressClassMap>
ParseSymbols(Symtab * symtab,user_id_t start_id,SectionList * section_list,const size_t num_symbols,const DataExtractor & symtab_data,const DataExtractor & strtab_data)2081 ObjectFileELF::ParseSymbols(Symtab *symtab, user_id_t start_id,
2082 SectionList *section_list, const size_t num_symbols,
2083 const DataExtractor &symtab_data,
2084 const DataExtractor &strtab_data) {
2085 ELFSymbol symbol;
2086 lldb::offset_t offset = 0;
2087 // The changes these symbols would make to the class map. We will also update
2088 // m_address_class_map but need to tell the caller what changed because the
2089 // caller may be another object file.
2090 FileAddressToAddressClassMap address_class_map;
2091
2092 static ConstString text_section_name(".text");
2093 static ConstString init_section_name(".init");
2094 static ConstString fini_section_name(".fini");
2095 static ConstString ctors_section_name(".ctors");
2096 static ConstString dtors_section_name(".dtors");
2097
2098 static ConstString data_section_name(".data");
2099 static ConstString rodata_section_name(".rodata");
2100 static ConstString rodata1_section_name(".rodata1");
2101 static ConstString data2_section_name(".data1");
2102 static ConstString bss_section_name(".bss");
2103 static ConstString opd_section_name(".opd"); // For ppc64
2104
2105 // On Android the oatdata and the oatexec symbols in the oat and odex files
2106 // covers the full .text section what causes issues with displaying unusable
2107 // symbol name to the user and very slow unwinding speed because the
2108 // instruction emulation based unwind plans try to emulate all instructions
2109 // in these symbols. Don't add these symbols to the symbol list as they have
2110 // no use for the debugger and they are causing a lot of trouble. Filtering
2111 // can't be restricted to Android because this special object file don't
2112 // contain the note section specifying the environment to Android but the
2113 // custom extension and file name makes it highly unlikely that this will
2114 // collide with anything else.
2115 llvm::StringRef file_extension = m_file.GetFileNameExtension();
2116 bool skip_oatdata_oatexec =
2117 file_extension == ".oat" || file_extension == ".odex";
2118
2119 ArchSpec arch = GetArchitecture();
2120 ModuleSP module_sp(GetModule());
2121 SectionList *module_section_list =
2122 module_sp ? module_sp->GetSectionList() : nullptr;
2123
2124 // We might have debug information in a separate object, in which case
2125 // we need to map the sections from that object to the sections in the
2126 // main object during symbol lookup. If we had to compare the sections
2127 // for every single symbol, that would be expensive, so this map is
2128 // used to accelerate the process.
2129 std::unordered_map<lldb::SectionSP, lldb::SectionSP> section_map;
2130
2131 unsigned i;
2132 for (i = 0; i < num_symbols; ++i) {
2133 if (!symbol.Parse(symtab_data, &offset))
2134 break;
2135
2136 const char *symbol_name = strtab_data.PeekCStr(symbol.st_name);
2137 if (!symbol_name)
2138 symbol_name = "";
2139
2140 // No need to add non-section symbols that have no names
2141 if (symbol.getType() != STT_SECTION &&
2142 (symbol_name == nullptr || symbol_name[0] == '\0'))
2143 continue;
2144
2145 // Skipping oatdata and oatexec sections if it is requested. See details
2146 // above the definition of skip_oatdata_oatexec for the reasons.
2147 if (skip_oatdata_oatexec && (::strcmp(symbol_name, "oatdata") == 0 ||
2148 ::strcmp(symbol_name, "oatexec") == 0))
2149 continue;
2150
2151 SectionSP symbol_section_sp;
2152 SymbolType symbol_type = eSymbolTypeInvalid;
2153 Elf64_Half shndx = symbol.st_shndx;
2154
2155 switch (shndx) {
2156 case SHN_ABS:
2157 symbol_type = eSymbolTypeAbsolute;
2158 break;
2159 case SHN_UNDEF:
2160 symbol_type = eSymbolTypeUndefined;
2161 break;
2162 default:
2163 symbol_section_sp = section_list->FindSectionByID(shndx);
2164 break;
2165 }
2166
2167 // If a symbol is undefined do not process it further even if it has a STT
2168 // type
2169 if (symbol_type != eSymbolTypeUndefined) {
2170 switch (symbol.getType()) {
2171 default:
2172 case STT_NOTYPE:
2173 // The symbol's type is not specified.
2174 break;
2175
2176 case STT_OBJECT:
2177 // The symbol is associated with a data object, such as a variable, an
2178 // array, etc.
2179 symbol_type = eSymbolTypeData;
2180 break;
2181
2182 case STT_FUNC:
2183 // The symbol is associated with a function or other executable code.
2184 symbol_type = eSymbolTypeCode;
2185 break;
2186
2187 case STT_SECTION:
2188 // The symbol is associated with a section. Symbol table entries of
2189 // this type exist primarily for relocation and normally have STB_LOCAL
2190 // binding.
2191 break;
2192
2193 case STT_FILE:
2194 // Conventionally, the symbol's name gives the name of the source file
2195 // associated with the object file. A file symbol has STB_LOCAL
2196 // binding, its section index is SHN_ABS, and it precedes the other
2197 // STB_LOCAL symbols for the file, if it is present.
2198 symbol_type = eSymbolTypeSourceFile;
2199 break;
2200
2201 case STT_GNU_IFUNC:
2202 // The symbol is associated with an indirect function. The actual
2203 // function will be resolved if it is referenced.
2204 symbol_type = eSymbolTypeResolver;
2205 break;
2206 }
2207 }
2208
2209 if (symbol_type == eSymbolTypeInvalid && symbol.getType() != STT_SECTION) {
2210 if (symbol_section_sp) {
2211 ConstString sect_name = symbol_section_sp->GetName();
2212 if (sect_name == text_section_name || sect_name == init_section_name ||
2213 sect_name == fini_section_name || sect_name == ctors_section_name ||
2214 sect_name == dtors_section_name) {
2215 symbol_type = eSymbolTypeCode;
2216 } else if (sect_name == data_section_name ||
2217 sect_name == data2_section_name ||
2218 sect_name == rodata_section_name ||
2219 sect_name == rodata1_section_name ||
2220 sect_name == bss_section_name) {
2221 symbol_type = eSymbolTypeData;
2222 }
2223 }
2224 }
2225
2226 int64_t symbol_value_offset = 0;
2227 uint32_t additional_flags = 0;
2228
2229 if (arch.IsValid()) {
2230 if (arch.GetMachine() == llvm::Triple::arm) {
2231 if (symbol.getBinding() == STB_LOCAL) {
2232 char mapping_symbol = FindArmAarch64MappingSymbol(symbol_name);
2233 if (symbol_type == eSymbolTypeCode) {
2234 switch (mapping_symbol) {
2235 case 'a':
2236 // $a[.<any>]* - marks an ARM instruction sequence
2237 address_class_map[symbol.st_value] = AddressClass::eCode;
2238 break;
2239 case 'b':
2240 case 't':
2241 // $b[.<any>]* - marks a THUMB BL instruction sequence
2242 // $t[.<any>]* - marks a THUMB instruction sequence
2243 address_class_map[symbol.st_value] =
2244 AddressClass::eCodeAlternateISA;
2245 break;
2246 case 'd':
2247 // $d[.<any>]* - marks a data item sequence (e.g. lit pool)
2248 address_class_map[symbol.st_value] = AddressClass::eData;
2249 break;
2250 }
2251 }
2252 if (mapping_symbol)
2253 continue;
2254 }
2255 } else if (arch.GetMachine() == llvm::Triple::aarch64) {
2256 if (symbol.getBinding() == STB_LOCAL) {
2257 char mapping_symbol = FindArmAarch64MappingSymbol(symbol_name);
2258 if (symbol_type == eSymbolTypeCode) {
2259 switch (mapping_symbol) {
2260 case 'x':
2261 // $x[.<any>]* - marks an A64 instruction sequence
2262 address_class_map[symbol.st_value] = AddressClass::eCode;
2263 break;
2264 case 'd':
2265 // $d[.<any>]* - marks a data item sequence (e.g. lit pool)
2266 address_class_map[symbol.st_value] = AddressClass::eData;
2267 break;
2268 }
2269 }
2270 if (mapping_symbol)
2271 continue;
2272 }
2273 }
2274
2275 if (arch.GetMachine() == llvm::Triple::arm) {
2276 if (symbol_type == eSymbolTypeCode) {
2277 if (symbol.st_value & 1) {
2278 // Subtracting 1 from the address effectively unsets the low order
2279 // bit, which results in the address actually pointing to the
2280 // beginning of the symbol. This delta will be used below in
2281 // conjunction with symbol.st_value to produce the final
2282 // symbol_value that we store in the symtab.
2283 symbol_value_offset = -1;
2284 address_class_map[symbol.st_value ^ 1] =
2285 AddressClass::eCodeAlternateISA;
2286 } else {
2287 // This address is ARM
2288 address_class_map[symbol.st_value] = AddressClass::eCode;
2289 }
2290 }
2291 }
2292
2293 /*
2294 * MIPS:
2295 * The bit #0 of an address is used for ISA mode (1 for microMIPS, 0 for
2296 * MIPS).
2297 * This allows processor to switch between microMIPS and MIPS without any
2298 * need
2299 * for special mode-control register. However, apart from .debug_line,
2300 * none of
2301 * the ELF/DWARF sections set the ISA bit (for symbol or section). Use
2302 * st_other
2303 * flag to check whether the symbol is microMIPS and then set the address
2304 * class
2305 * accordingly.
2306 */
2307 if (arch.IsMIPS()) {
2308 if (IS_MICROMIPS(symbol.st_other))
2309 address_class_map[symbol.st_value] = AddressClass::eCodeAlternateISA;
2310 else if ((symbol.st_value & 1) && (symbol_type == eSymbolTypeCode)) {
2311 symbol.st_value = symbol.st_value & (~1ull);
2312 address_class_map[symbol.st_value] = AddressClass::eCodeAlternateISA;
2313 } else {
2314 if (symbol_type == eSymbolTypeCode)
2315 address_class_map[symbol.st_value] = AddressClass::eCode;
2316 else if (symbol_type == eSymbolTypeData)
2317 address_class_map[symbol.st_value] = AddressClass::eData;
2318 else
2319 address_class_map[symbol.st_value] = AddressClass::eUnknown;
2320 }
2321 }
2322 }
2323
2324 // symbol_value_offset may contain 0 for ARM symbols or -1 for THUMB
2325 // symbols. See above for more details.
2326 uint64_t symbol_value = symbol.st_value + symbol_value_offset;
2327
2328 if (symbol_section_sp &&
2329 CalculateType() != ObjectFile::Type::eTypeObjectFile)
2330 symbol_value -= symbol_section_sp->GetFileAddress();
2331
2332 if (symbol_section_sp && module_section_list &&
2333 module_section_list != section_list) {
2334 auto section_it = section_map.find(symbol_section_sp);
2335 if (section_it == section_map.end()) {
2336 section_it = section_map
2337 .emplace(symbol_section_sp,
2338 FindMatchingSection(*module_section_list,
2339 symbol_section_sp))
2340 .first;
2341 }
2342 if (section_it->second)
2343 symbol_section_sp = section_it->second;
2344 }
2345
2346 bool is_global = symbol.getBinding() == STB_GLOBAL;
2347 uint32_t flags = symbol.st_other << 8 | symbol.st_info | additional_flags;
2348 llvm::StringRef symbol_ref(symbol_name);
2349
2350 // Symbol names may contain @VERSION suffixes. Find those and strip them
2351 // temporarily.
2352 size_t version_pos = symbol_ref.find('@');
2353 bool has_suffix = version_pos != llvm::StringRef::npos;
2354 llvm::StringRef symbol_bare = symbol_ref.substr(0, version_pos);
2355 Mangled mangled(symbol_bare);
2356
2357 // Now append the suffix back to mangled and unmangled names. Only do it if
2358 // the demangling was successful (string is not empty).
2359 if (has_suffix) {
2360 llvm::StringRef suffix = symbol_ref.substr(version_pos);
2361
2362 llvm::StringRef mangled_name = mangled.GetMangledName().GetStringRef();
2363 if (!mangled_name.empty())
2364 mangled.SetMangledName(ConstString((mangled_name + suffix).str()));
2365
2366 ConstString demangled = mangled.GetDemangledName();
2367 llvm::StringRef demangled_name = demangled.GetStringRef();
2368 if (!demangled_name.empty())
2369 mangled.SetDemangledName(ConstString((demangled_name + suffix).str()));
2370 }
2371
2372 // In ELF all symbol should have a valid size but it is not true for some
2373 // function symbols coming from hand written assembly. As none of the
2374 // function symbol should have 0 size we try to calculate the size for
2375 // these symbols in the symtab with saying that their original size is not
2376 // valid.
2377 bool symbol_size_valid =
2378 symbol.st_size != 0 || symbol.getType() != STT_FUNC;
2379
2380 bool is_trampoline = false;
2381 if (arch.IsValid() && (arch.GetMachine() == llvm::Triple::aarch64)) {
2382 // On AArch64, trampolines are registered as code.
2383 // If we detect a trampoline (which starts with __AArch64ADRPThunk_ or
2384 // __AArch64AbsLongThunk_) we register the symbol as a trampoline. This
2385 // way we will be able to detect the trampoline when we step in a function
2386 // and step through the trampoline.
2387 if (symbol_type == eSymbolTypeCode) {
2388 llvm::StringRef trampoline_name = mangled.GetName().GetStringRef();
2389 if (trampoline_name.starts_with("__AArch64ADRPThunk_") ||
2390 trampoline_name.starts_with("__AArch64AbsLongThunk_")) {
2391 symbol_type = eSymbolTypeTrampoline;
2392 is_trampoline = true;
2393 }
2394 }
2395 }
2396
2397 Symbol dc_symbol(
2398 i + start_id, // ID is the original symbol table index.
2399 mangled,
2400 symbol_type, // Type of this symbol
2401 is_global, // Is this globally visible?
2402 false, // Is this symbol debug info?
2403 is_trampoline, // Is this symbol a trampoline?
2404 false, // Is this symbol artificial?
2405 AddressRange(symbol_section_sp, // Section in which this symbol is
2406 // defined or null.
2407 symbol_value, // Offset in section or symbol value.
2408 symbol.st_size), // Size in bytes of this symbol.
2409 symbol_size_valid, // Symbol size is valid
2410 has_suffix, // Contains linker annotations?
2411 flags); // Symbol flags.
2412 if (symbol.getBinding() == STB_WEAK)
2413 dc_symbol.SetIsWeak(true);
2414 symtab->AddSymbol(dc_symbol);
2415 }
2416
2417 m_address_class_map.merge(address_class_map);
2418 return {i, address_class_map};
2419 }
2420
2421 std::pair<unsigned, ObjectFileELF::FileAddressToAddressClassMap>
ParseSymbolTable(Symtab * symbol_table,user_id_t start_id,lldb_private::Section * symtab)2422 ObjectFileELF::ParseSymbolTable(Symtab *symbol_table, user_id_t start_id,
2423 lldb_private::Section *symtab) {
2424 if (symtab->GetObjectFile() != this) {
2425 // If the symbol table section is owned by a different object file, have it
2426 // do the parsing.
2427 ObjectFileELF *obj_file_elf =
2428 static_cast<ObjectFileELF *>(symtab->GetObjectFile());
2429 auto [num_symbols, address_class_map] =
2430 obj_file_elf->ParseSymbolTable(symbol_table, start_id, symtab);
2431
2432 // The other object file returned the changes it made to its address
2433 // class map, make the same changes to ours.
2434 m_address_class_map.merge(address_class_map);
2435
2436 return {num_symbols, address_class_map};
2437 }
2438
2439 // Get section list for this object file.
2440 SectionList *section_list = m_sections_up.get();
2441 if (!section_list)
2442 return {};
2443
2444 user_id_t symtab_id = symtab->GetID();
2445 const ELFSectionHeaderInfo *symtab_hdr = GetSectionHeaderByIndex(symtab_id);
2446 assert(symtab_hdr->sh_type == SHT_SYMTAB ||
2447 symtab_hdr->sh_type == SHT_DYNSYM);
2448
2449 // sh_link: section header index of associated string table.
2450 user_id_t strtab_id = symtab_hdr->sh_link;
2451 Section *strtab = section_list->FindSectionByID(strtab_id).get();
2452
2453 if (symtab && strtab) {
2454 assert(symtab->GetObjectFile() == this);
2455 assert(strtab->GetObjectFile() == this);
2456
2457 DataExtractor symtab_data;
2458 DataExtractor strtab_data;
2459 if (ReadSectionData(symtab, symtab_data) &&
2460 ReadSectionData(strtab, strtab_data)) {
2461 size_t num_symbols = symtab_data.GetByteSize() / symtab_hdr->sh_entsize;
2462
2463 return ParseSymbols(symbol_table, start_id, section_list, num_symbols,
2464 symtab_data, strtab_data);
2465 }
2466 }
2467
2468 return {0, {}};
2469 }
2470
ParseDynamicSymbols()2471 size_t ObjectFileELF::ParseDynamicSymbols() {
2472 if (m_dynamic_symbols.size())
2473 return m_dynamic_symbols.size();
2474
2475 SectionList *section_list = GetSectionList();
2476 if (!section_list)
2477 return 0;
2478
2479 // Find the SHT_DYNAMIC section.
2480 Section *dynsym =
2481 section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true)
2482 .get();
2483 if (!dynsym)
2484 return 0;
2485 assert(dynsym->GetObjectFile() == this);
2486
2487 ELFDynamic symbol;
2488 DataExtractor dynsym_data;
2489 if (ReadSectionData(dynsym, dynsym_data)) {
2490 const lldb::offset_t section_size = dynsym_data.GetByteSize();
2491 lldb::offset_t cursor = 0;
2492
2493 while (cursor < section_size) {
2494 if (!symbol.Parse(dynsym_data, &cursor))
2495 break;
2496
2497 m_dynamic_symbols.push_back(symbol);
2498 }
2499 }
2500
2501 return m_dynamic_symbols.size();
2502 }
2503
FindDynamicSymbol(unsigned tag)2504 const ELFDynamic *ObjectFileELF::FindDynamicSymbol(unsigned tag) {
2505 if (!ParseDynamicSymbols())
2506 return nullptr;
2507
2508 DynamicSymbolCollIter I = m_dynamic_symbols.begin();
2509 DynamicSymbolCollIter E = m_dynamic_symbols.end();
2510 for (; I != E; ++I) {
2511 ELFDynamic *symbol = &*I;
2512
2513 if (symbol->d_tag == tag)
2514 return symbol;
2515 }
2516
2517 return nullptr;
2518 }
2519
PLTRelocationType()2520 unsigned ObjectFileELF::PLTRelocationType() {
2521 // DT_PLTREL
2522 // This member specifies the type of relocation entry to which the
2523 // procedure linkage table refers. The d_val member holds DT_REL or
2524 // DT_RELA, as appropriate. All relocations in a procedure linkage table
2525 // must use the same relocation.
2526 const ELFDynamic *symbol = FindDynamicSymbol(DT_PLTREL);
2527
2528 if (symbol)
2529 return symbol->d_val;
2530
2531 return 0;
2532 }
2533
2534 // Returns the size of the normal plt entries and the offset of the first
2535 // normal plt entry. The 0th entry in the plt table is usually a resolution
2536 // entry which have different size in some architectures then the rest of the
2537 // plt entries.
2538 static std::pair<uint64_t, uint64_t>
GetPltEntrySizeAndOffset(const ELFSectionHeader * rel_hdr,const ELFSectionHeader * plt_hdr)2539 GetPltEntrySizeAndOffset(const ELFSectionHeader *rel_hdr,
2540 const ELFSectionHeader *plt_hdr) {
2541 const elf_xword num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2542
2543 // Clang 3.3 sets entsize to 4 for 32-bit binaries, but the plt entries are
2544 // 16 bytes. So round the entsize up by the alignment if addralign is set.
2545 elf_xword plt_entsize =
2546 plt_hdr->sh_addralign
2547 ? llvm::alignTo(plt_hdr->sh_entsize, plt_hdr->sh_addralign)
2548 : plt_hdr->sh_entsize;
2549
2550 // Some linkers e.g ld for arm, fill plt_hdr->sh_entsize field incorrectly.
2551 // PLT entries relocation code in general requires multiple instruction and
2552 // should be greater than 4 bytes in most cases. Try to guess correct size
2553 // just in case.
2554 if (plt_entsize <= 4) {
2555 // The linker haven't set the plt_hdr->sh_entsize field. Try to guess the
2556 // size of the plt entries based on the number of entries and the size of
2557 // the plt section with the assumption that the size of the 0th entry is at
2558 // least as big as the size of the normal entries and it isn't much bigger
2559 // then that.
2560 if (plt_hdr->sh_addralign)
2561 plt_entsize = plt_hdr->sh_size / plt_hdr->sh_addralign /
2562 (num_relocations + 1) * plt_hdr->sh_addralign;
2563 else
2564 plt_entsize = plt_hdr->sh_size / (num_relocations + 1);
2565 }
2566
2567 elf_xword plt_offset = plt_hdr->sh_size - num_relocations * plt_entsize;
2568
2569 return std::make_pair(plt_entsize, plt_offset);
2570 }
2571
ParsePLTRelocations(Symtab * symbol_table,user_id_t start_id,unsigned rel_type,const ELFHeader * hdr,const ELFSectionHeader * rel_hdr,const ELFSectionHeader * plt_hdr,const ELFSectionHeader * sym_hdr,const lldb::SectionSP & plt_section_sp,DataExtractor & rel_data,DataExtractor & symtab_data,DataExtractor & strtab_data)2572 static unsigned ParsePLTRelocations(
2573 Symtab *symbol_table, user_id_t start_id, unsigned rel_type,
2574 const ELFHeader *hdr, const ELFSectionHeader *rel_hdr,
2575 const ELFSectionHeader *plt_hdr, const ELFSectionHeader *sym_hdr,
2576 const lldb::SectionSP &plt_section_sp, DataExtractor &rel_data,
2577 DataExtractor &symtab_data, DataExtractor &strtab_data) {
2578 ELFRelocation rel(rel_type);
2579 ELFSymbol symbol;
2580 lldb::offset_t offset = 0;
2581
2582 uint64_t plt_offset, plt_entsize;
2583 std::tie(plt_entsize, plt_offset) =
2584 GetPltEntrySizeAndOffset(rel_hdr, plt_hdr);
2585 const elf_xword num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2586
2587 typedef unsigned (*reloc_info_fn)(const ELFRelocation &rel);
2588 reloc_info_fn reloc_type;
2589 reloc_info_fn reloc_symbol;
2590
2591 if (hdr->Is32Bit()) {
2592 reloc_type = ELFRelocation::RelocType32;
2593 reloc_symbol = ELFRelocation::RelocSymbol32;
2594 } else {
2595 reloc_type = ELFRelocation::RelocType64;
2596 reloc_symbol = ELFRelocation::RelocSymbol64;
2597 }
2598
2599 unsigned slot_type = hdr->GetRelocationJumpSlotType();
2600 unsigned i;
2601 for (i = 0; i < num_relocations; ++i) {
2602 if (!rel.Parse(rel_data, &offset))
2603 break;
2604
2605 if (reloc_type(rel) != slot_type)
2606 continue;
2607
2608 lldb::offset_t symbol_offset = reloc_symbol(rel) * sym_hdr->sh_entsize;
2609 if (!symbol.Parse(symtab_data, &symbol_offset))
2610 break;
2611
2612 const char *symbol_name = strtab_data.PeekCStr(symbol.st_name);
2613 uint64_t plt_index = plt_offset + i * plt_entsize;
2614
2615 Symbol jump_symbol(
2616 i + start_id, // Symbol table index
2617 symbol_name, // symbol name.
2618 eSymbolTypeTrampoline, // Type of this symbol
2619 false, // Is this globally visible?
2620 false, // Is this symbol debug info?
2621 true, // Is this symbol a trampoline?
2622 true, // Is this symbol artificial?
2623 plt_section_sp, // Section in which this symbol is defined or null.
2624 plt_index, // Offset in section or symbol value.
2625 plt_entsize, // Size in bytes of this symbol.
2626 true, // Size is valid
2627 false, // Contains linker annotations?
2628 0); // Symbol flags.
2629
2630 symbol_table->AddSymbol(jump_symbol);
2631 }
2632
2633 return i;
2634 }
2635
2636 unsigned
ParseTrampolineSymbols(Symtab * symbol_table,user_id_t start_id,const ELFSectionHeaderInfo * rel_hdr,user_id_t rel_id)2637 ObjectFileELF::ParseTrampolineSymbols(Symtab *symbol_table, user_id_t start_id,
2638 const ELFSectionHeaderInfo *rel_hdr,
2639 user_id_t rel_id) {
2640 assert(rel_hdr->sh_type == SHT_RELA || rel_hdr->sh_type == SHT_REL);
2641
2642 // The link field points to the associated symbol table.
2643 user_id_t symtab_id = rel_hdr->sh_link;
2644
2645 // If the link field doesn't point to the appropriate symbol name table then
2646 // try to find it by name as some compiler don't fill in the link fields.
2647 if (!symtab_id)
2648 symtab_id = GetSectionIndexByName(".dynsym");
2649
2650 // Get PLT section. We cannot use rel_hdr->sh_info, since current linkers
2651 // point that to the .got.plt or .got section instead of .plt.
2652 user_id_t plt_id = GetSectionIndexByName(".plt");
2653
2654 if (!symtab_id || !plt_id)
2655 return 0;
2656
2657 const ELFSectionHeaderInfo *plt_hdr = GetSectionHeaderByIndex(plt_id);
2658 if (!plt_hdr)
2659 return 0;
2660
2661 const ELFSectionHeaderInfo *sym_hdr = GetSectionHeaderByIndex(symtab_id);
2662 if (!sym_hdr)
2663 return 0;
2664
2665 SectionList *section_list = m_sections_up.get();
2666 if (!section_list)
2667 return 0;
2668
2669 Section *rel_section = section_list->FindSectionByID(rel_id).get();
2670 if (!rel_section)
2671 return 0;
2672
2673 SectionSP plt_section_sp(section_list->FindSectionByID(plt_id));
2674 if (!plt_section_sp)
2675 return 0;
2676
2677 Section *symtab = section_list->FindSectionByID(symtab_id).get();
2678 if (!symtab)
2679 return 0;
2680
2681 // sh_link points to associated string table.
2682 Section *strtab = section_list->FindSectionByID(sym_hdr->sh_link).get();
2683 if (!strtab)
2684 return 0;
2685
2686 DataExtractor rel_data;
2687 if (!ReadSectionData(rel_section, rel_data))
2688 return 0;
2689
2690 DataExtractor symtab_data;
2691 if (!ReadSectionData(symtab, symtab_data))
2692 return 0;
2693
2694 DataExtractor strtab_data;
2695 if (!ReadSectionData(strtab, strtab_data))
2696 return 0;
2697
2698 unsigned rel_type = PLTRelocationType();
2699 if (!rel_type)
2700 return 0;
2701
2702 return ParsePLTRelocations(symbol_table, start_id, rel_type, &m_header,
2703 rel_hdr, plt_hdr, sym_hdr, plt_section_sp,
2704 rel_data, symtab_data, strtab_data);
2705 }
2706
ApplyELF64ABS64Relocation(Symtab * symtab,ELFRelocation & rel,DataExtractor & debug_data,Section * rel_section)2707 static void ApplyELF64ABS64Relocation(Symtab *symtab, ELFRelocation &rel,
2708 DataExtractor &debug_data,
2709 Section *rel_section) {
2710 Symbol *symbol = symtab->FindSymbolByID(ELFRelocation::RelocSymbol64(rel));
2711 if (symbol) {
2712 addr_t value = symbol->GetAddressRef().GetFileAddress();
2713 DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2714 // ObjectFileELF creates a WritableDataBuffer in CreateInstance.
2715 WritableDataBuffer *data_buffer =
2716 llvm::cast<WritableDataBuffer>(data_buffer_sp.get());
2717 uint64_t *dst = reinterpret_cast<uint64_t *>(
2718 data_buffer->GetBytes() + rel_section->GetFileOffset() +
2719 ELFRelocation::RelocOffset64(rel));
2720 uint64_t val_offset = value + ELFRelocation::RelocAddend64(rel);
2721 memcpy(dst, &val_offset, sizeof(uint64_t));
2722 }
2723 }
2724
ApplyELF64ABS32Relocation(Symtab * symtab,ELFRelocation & rel,DataExtractor & debug_data,Section * rel_section,bool is_signed)2725 static void ApplyELF64ABS32Relocation(Symtab *symtab, ELFRelocation &rel,
2726 DataExtractor &debug_data,
2727 Section *rel_section, bool is_signed) {
2728 Symbol *symbol = symtab->FindSymbolByID(ELFRelocation::RelocSymbol64(rel));
2729 if (symbol) {
2730 addr_t value = symbol->GetAddressRef().GetFileAddress();
2731 value += ELFRelocation::RelocAddend32(rel);
2732 if ((!is_signed && (value > UINT32_MAX)) ||
2733 (is_signed &&
2734 ((int64_t)value > INT32_MAX || (int64_t)value < INT32_MIN))) {
2735 Log *log = GetLog(LLDBLog::Modules);
2736 LLDB_LOGF(log, "Failed to apply debug info relocations");
2737 return;
2738 }
2739 uint32_t truncated_addr = (value & 0xFFFFFFFF);
2740 DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2741 // ObjectFileELF creates a WritableDataBuffer in CreateInstance.
2742 WritableDataBuffer *data_buffer =
2743 llvm::cast<WritableDataBuffer>(data_buffer_sp.get());
2744 uint32_t *dst = reinterpret_cast<uint32_t *>(
2745 data_buffer->GetBytes() + rel_section->GetFileOffset() +
2746 ELFRelocation::RelocOffset32(rel));
2747 memcpy(dst, &truncated_addr, sizeof(uint32_t));
2748 }
2749 }
2750
ApplyELF32ABS32RelRelocation(Symtab * symtab,ELFRelocation & rel,DataExtractor & debug_data,Section * rel_section)2751 static void ApplyELF32ABS32RelRelocation(Symtab *symtab, ELFRelocation &rel,
2752 DataExtractor &debug_data,
2753 Section *rel_section) {
2754 Log *log = GetLog(LLDBLog::Modules);
2755 Symbol *symbol = symtab->FindSymbolByID(ELFRelocation::RelocSymbol32(rel));
2756 if (symbol) {
2757 addr_t value = symbol->GetAddressRef().GetFileAddress();
2758 if (value == LLDB_INVALID_ADDRESS) {
2759 const char *name = symbol->GetName().GetCString();
2760 LLDB_LOGF(log, "Debug info symbol invalid: %s", name);
2761 return;
2762 }
2763 assert(llvm::isUInt<32>(value) && "Valid addresses are 32-bit");
2764 DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2765 // ObjectFileELF creates a WritableDataBuffer in CreateInstance.
2766 WritableDataBuffer *data_buffer =
2767 llvm::cast<WritableDataBuffer>(data_buffer_sp.get());
2768 uint8_t *dst = data_buffer->GetBytes() + rel_section->GetFileOffset() +
2769 ELFRelocation::RelocOffset32(rel);
2770 // Implicit addend is stored inline as a signed value.
2771 int32_t addend;
2772 memcpy(&addend, dst, sizeof(int32_t));
2773 // The sum must be positive. This extra check prevents UB from overflow in
2774 // the actual range check below.
2775 if (addend < 0 && static_cast<uint32_t>(-addend) > value) {
2776 LLDB_LOGF(log, "Debug info relocation overflow: 0x%" PRIx64,
2777 static_cast<int64_t>(value) + addend);
2778 return;
2779 }
2780 if (!llvm::isUInt<32>(value + addend)) {
2781 LLDB_LOGF(log, "Debug info relocation out of range: 0x%" PRIx64, value);
2782 return;
2783 }
2784 uint32_t addr = value + addend;
2785 memcpy(dst, &addr, sizeof(uint32_t));
2786 }
2787 }
2788
ApplyRelocations(Symtab * symtab,const ELFHeader * hdr,const ELFSectionHeader * rel_hdr,const ELFSectionHeader * symtab_hdr,const ELFSectionHeader * debug_hdr,DataExtractor & rel_data,DataExtractor & symtab_data,DataExtractor & debug_data,Section * rel_section)2789 unsigned ObjectFileELF::ApplyRelocations(
2790 Symtab *symtab, const ELFHeader *hdr, const ELFSectionHeader *rel_hdr,
2791 const ELFSectionHeader *symtab_hdr, const ELFSectionHeader *debug_hdr,
2792 DataExtractor &rel_data, DataExtractor &symtab_data,
2793 DataExtractor &debug_data, Section *rel_section) {
2794 ELFRelocation rel(rel_hdr->sh_type);
2795 lldb::addr_t offset = 0;
2796 const unsigned num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2797 typedef unsigned (*reloc_info_fn)(const ELFRelocation &rel);
2798 reloc_info_fn reloc_type;
2799 reloc_info_fn reloc_symbol;
2800
2801 if (hdr->Is32Bit()) {
2802 reloc_type = ELFRelocation::RelocType32;
2803 reloc_symbol = ELFRelocation::RelocSymbol32;
2804 } else {
2805 reloc_type = ELFRelocation::RelocType64;
2806 reloc_symbol = ELFRelocation::RelocSymbol64;
2807 }
2808
2809 for (unsigned i = 0; i < num_relocations; ++i) {
2810 if (!rel.Parse(rel_data, &offset)) {
2811 GetModule()->ReportError(".rel{0}[{1:d}] failed to parse relocation",
2812 rel_section->GetName().AsCString(), i);
2813 break;
2814 }
2815 Symbol *symbol = nullptr;
2816
2817 if (hdr->Is32Bit()) {
2818 switch (hdr->e_machine) {
2819 case llvm::ELF::EM_ARM:
2820 switch (reloc_type(rel)) {
2821 case R_ARM_ABS32:
2822 ApplyELF32ABS32RelRelocation(symtab, rel, debug_data, rel_section);
2823 break;
2824 case R_ARM_REL32:
2825 GetModule()->ReportError("unsupported AArch32 relocation:"
2826 " .rel{0}[{1}], type {2}",
2827 rel_section->GetName().AsCString(), i,
2828 reloc_type(rel));
2829 break;
2830 default:
2831 assert(false && "unexpected relocation type");
2832 }
2833 break;
2834 case llvm::ELF::EM_386:
2835 switch (reloc_type(rel)) {
2836 case R_386_32:
2837 symbol = symtab->FindSymbolByID(reloc_symbol(rel));
2838 if (symbol) {
2839 addr_t f_offset =
2840 rel_section->GetFileOffset() + ELFRelocation::RelocOffset32(rel);
2841 DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2842 // ObjectFileELF creates a WritableDataBuffer in CreateInstance.
2843 WritableDataBuffer *data_buffer =
2844 llvm::cast<WritableDataBuffer>(data_buffer_sp.get());
2845 uint32_t *dst = reinterpret_cast<uint32_t *>(
2846 data_buffer->GetBytes() + f_offset);
2847
2848 addr_t value = symbol->GetAddressRef().GetFileAddress();
2849 if (rel.IsRela()) {
2850 value += ELFRelocation::RelocAddend32(rel);
2851 } else {
2852 value += *dst;
2853 }
2854 *dst = value;
2855 } else {
2856 GetModule()->ReportError(".rel{0}[{1}] unknown symbol id: {2:d}",
2857 rel_section->GetName().AsCString(), i,
2858 reloc_symbol(rel));
2859 }
2860 break;
2861 case R_386_NONE:
2862 case R_386_PC32:
2863 GetModule()->ReportError("unsupported i386 relocation:"
2864 " .rel{0}[{1}], type {2}",
2865 rel_section->GetName().AsCString(), i,
2866 reloc_type(rel));
2867 break;
2868 default:
2869 assert(false && "unexpected relocation type");
2870 break;
2871 }
2872 break;
2873 default:
2874 GetModule()->ReportError("unsupported 32-bit ELF machine arch: {0}", hdr->e_machine);
2875 break;
2876 }
2877 } else {
2878 switch (hdr->e_machine) {
2879 case llvm::ELF::EM_AARCH64:
2880 switch (reloc_type(rel)) {
2881 case R_AARCH64_ABS64:
2882 ApplyELF64ABS64Relocation(symtab, rel, debug_data, rel_section);
2883 break;
2884 case R_AARCH64_ABS32:
2885 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section, true);
2886 break;
2887 default:
2888 assert(false && "unexpected relocation type");
2889 }
2890 break;
2891 case llvm::ELF::EM_LOONGARCH:
2892 switch (reloc_type(rel)) {
2893 case R_LARCH_64:
2894 ApplyELF64ABS64Relocation(symtab, rel, debug_data, rel_section);
2895 break;
2896 case R_LARCH_32:
2897 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section, true);
2898 break;
2899 default:
2900 assert(false && "unexpected relocation type");
2901 }
2902 break;
2903 case llvm::ELF::EM_X86_64:
2904 switch (reloc_type(rel)) {
2905 case R_X86_64_64:
2906 ApplyELF64ABS64Relocation(symtab, rel, debug_data, rel_section);
2907 break;
2908 case R_X86_64_32:
2909 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section,
2910 false);
2911 break;
2912 case R_X86_64_32S:
2913 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section, true);
2914 break;
2915 case R_X86_64_PC32:
2916 default:
2917 assert(false && "unexpected relocation type");
2918 }
2919 break;
2920 default:
2921 GetModule()->ReportError("unsupported 64-bit ELF machine arch: {0}", hdr->e_machine);
2922 break;
2923 }
2924 }
2925 }
2926
2927 return 0;
2928 }
2929
RelocateDebugSections(const ELFSectionHeader * rel_hdr,user_id_t rel_id,lldb_private::Symtab * thetab)2930 unsigned ObjectFileELF::RelocateDebugSections(const ELFSectionHeader *rel_hdr,
2931 user_id_t rel_id,
2932 lldb_private::Symtab *thetab) {
2933 assert(rel_hdr->sh_type == SHT_RELA || rel_hdr->sh_type == SHT_REL);
2934
2935 // Parse in the section list if needed.
2936 SectionList *section_list = GetSectionList();
2937 if (!section_list)
2938 return 0;
2939
2940 user_id_t symtab_id = rel_hdr->sh_link;
2941 user_id_t debug_id = rel_hdr->sh_info;
2942
2943 const ELFSectionHeader *symtab_hdr = GetSectionHeaderByIndex(symtab_id);
2944 if (!symtab_hdr)
2945 return 0;
2946
2947 const ELFSectionHeader *debug_hdr = GetSectionHeaderByIndex(debug_id);
2948 if (!debug_hdr)
2949 return 0;
2950
2951 Section *rel = section_list->FindSectionByID(rel_id).get();
2952 if (!rel)
2953 return 0;
2954
2955 Section *symtab = section_list->FindSectionByID(symtab_id).get();
2956 if (!symtab)
2957 return 0;
2958
2959 Section *debug = section_list->FindSectionByID(debug_id).get();
2960 if (!debug)
2961 return 0;
2962
2963 DataExtractor rel_data;
2964 DataExtractor symtab_data;
2965 DataExtractor debug_data;
2966
2967 if (GetData(rel->GetFileOffset(), rel->GetFileSize(), rel_data) &&
2968 GetData(symtab->GetFileOffset(), symtab->GetFileSize(), symtab_data) &&
2969 GetData(debug->GetFileOffset(), debug->GetFileSize(), debug_data)) {
2970 ApplyRelocations(thetab, &m_header, rel_hdr, symtab_hdr, debug_hdr,
2971 rel_data, symtab_data, debug_data, debug);
2972 }
2973
2974 return 0;
2975 }
2976
ParseSymtab(Symtab & lldb_symtab)2977 void ObjectFileELF::ParseSymtab(Symtab &lldb_symtab) {
2978 ModuleSP module_sp(GetModule());
2979 if (!module_sp)
2980 return;
2981
2982 Progress progress("Parsing symbol table",
2983 m_file.GetFilename().AsCString("<Unknown>"));
2984 ElapsedTime elapsed(module_sp->GetSymtabParseTime());
2985
2986 // We always want to use the main object file so we (hopefully) only have one
2987 // cached copy of our symtab, dynamic sections, etc.
2988 ObjectFile *module_obj_file = module_sp->GetObjectFile();
2989 if (module_obj_file && module_obj_file != this)
2990 return module_obj_file->ParseSymtab(lldb_symtab);
2991
2992 SectionList *section_list = module_sp->GetSectionList();
2993 if (!section_list)
2994 return;
2995
2996 uint64_t symbol_id = 0;
2997
2998 // Sharable objects and dynamic executables usually have 2 distinct symbol
2999 // tables, one named ".symtab", and the other ".dynsym". The dynsym is a
3000 // smaller version of the symtab that only contains global symbols. The
3001 // information found in the dynsym is therefore also found in the symtab,
3002 // while the reverse is not necessarily true.
3003 Section *symtab =
3004 section_list->FindSectionByType(eSectionTypeELFSymbolTable, true).get();
3005 if (symtab) {
3006 auto [num_symbols, address_class_map] =
3007 ParseSymbolTable(&lldb_symtab, symbol_id, symtab);
3008 m_address_class_map.merge(address_class_map);
3009 symbol_id += num_symbols;
3010 }
3011
3012 // The symtab section is non-allocable and can be stripped, while the
3013 // .dynsym section which should always be always be there. To support the
3014 // minidebuginfo case we parse .dynsym when there's a .gnu_debuginfo
3015 // section, nomatter if .symtab was already parsed or not. This is because
3016 // minidebuginfo normally removes the .symtab symbols which have their
3017 // matching .dynsym counterparts.
3018 if (!symtab ||
3019 GetSectionList()->FindSectionByName(ConstString(".gnu_debugdata"))) {
3020 Section *dynsym =
3021 section_list->FindSectionByType(eSectionTypeELFDynamicSymbols, true)
3022 .get();
3023 if (dynsym) {
3024 auto [num_symbols, address_class_map] =
3025 ParseSymbolTable(&lldb_symtab, symbol_id, dynsym);
3026 symbol_id += num_symbols;
3027 m_address_class_map.merge(address_class_map);
3028 }
3029 }
3030
3031 // DT_JMPREL
3032 // If present, this entry's d_ptr member holds the address of
3033 // relocation
3034 // entries associated solely with the procedure linkage table.
3035 // Separating
3036 // these relocation entries lets the dynamic linker ignore them during
3037 // process initialization, if lazy binding is enabled. If this entry is
3038 // present, the related entries of types DT_PLTRELSZ and DT_PLTREL must
3039 // also be present.
3040 const ELFDynamic *symbol = FindDynamicSymbol(DT_JMPREL);
3041 if (symbol) {
3042 // Synthesize trampoline symbols to help navigate the PLT.
3043 addr_t addr = symbol->d_ptr;
3044 Section *reloc_section =
3045 section_list->FindSectionContainingFileAddress(addr).get();
3046 if (reloc_section) {
3047 user_id_t reloc_id = reloc_section->GetID();
3048 const ELFSectionHeaderInfo *reloc_header =
3049 GetSectionHeaderByIndex(reloc_id);
3050 if (reloc_header)
3051 ParseTrampolineSymbols(&lldb_symtab, symbol_id, reloc_header, reloc_id);
3052 }
3053 }
3054
3055 if (DWARFCallFrameInfo *eh_frame =
3056 GetModule()->GetUnwindTable().GetEHFrameInfo()) {
3057 ParseUnwindSymbols(&lldb_symtab, eh_frame);
3058 }
3059
3060 // In the event that there's no symbol entry for the entry point we'll
3061 // artificially create one. We delegate to the symtab object the figuring
3062 // out of the proper size, this will usually make it span til the next
3063 // symbol it finds in the section. This means that if there are missing
3064 // symbols the entry point might span beyond its function definition.
3065 // We're fine with this as it doesn't make it worse than not having a
3066 // symbol entry at all.
3067 if (CalculateType() == eTypeExecutable) {
3068 ArchSpec arch = GetArchitecture();
3069 auto entry_point_addr = GetEntryPointAddress();
3070 bool is_valid_entry_point =
3071 entry_point_addr.IsValid() && entry_point_addr.IsSectionOffset();
3072 addr_t entry_point_file_addr = entry_point_addr.GetFileAddress();
3073 if (is_valid_entry_point && !lldb_symtab.FindSymbolContainingFileAddress(
3074 entry_point_file_addr)) {
3075 uint64_t symbol_id = lldb_symtab.GetNumSymbols();
3076 // Don't set the name for any synthetic symbols, the Symbol
3077 // object will generate one if needed when the name is accessed
3078 // via accessors.
3079 SectionSP section_sp = entry_point_addr.GetSection();
3080 Symbol symbol(
3081 /*symID=*/symbol_id,
3082 /*name=*/llvm::StringRef(), // Name will be auto generated.
3083 /*type=*/eSymbolTypeCode,
3084 /*external=*/true,
3085 /*is_debug=*/false,
3086 /*is_trampoline=*/false,
3087 /*is_artificial=*/true,
3088 /*section_sp=*/section_sp,
3089 /*offset=*/0,
3090 /*size=*/0, // FDE can span multiple symbols so don't use its size.
3091 /*size_is_valid=*/false,
3092 /*contains_linker_annotations=*/false,
3093 /*flags=*/0);
3094 // When the entry point is arm thumb we need to explicitly set its
3095 // class address to reflect that. This is important because expression
3096 // evaluation relies on correctly setting a breakpoint at this
3097 // address.
3098 if (arch.GetMachine() == llvm::Triple::arm &&
3099 (entry_point_file_addr & 1)) {
3100 symbol.GetAddressRef().SetOffset(entry_point_addr.GetOffset() ^ 1);
3101 m_address_class_map[entry_point_file_addr ^ 1] =
3102 AddressClass::eCodeAlternateISA;
3103 } else {
3104 m_address_class_map[entry_point_file_addr] = AddressClass::eCode;
3105 }
3106 lldb_symtab.AddSymbol(symbol);
3107 }
3108 }
3109 }
3110
RelocateSection(lldb_private::Section * section)3111 void ObjectFileELF::RelocateSection(lldb_private::Section *section)
3112 {
3113 static const char *debug_prefix = ".debug";
3114
3115 // Set relocated bit so we stop getting called, regardless of whether we
3116 // actually relocate.
3117 section->SetIsRelocated(true);
3118
3119 // We only relocate in ELF relocatable files
3120 if (CalculateType() != eTypeObjectFile)
3121 return;
3122
3123 const char *section_name = section->GetName().GetCString();
3124 // Can't relocate that which can't be named
3125 if (section_name == nullptr)
3126 return;
3127
3128 // We don't relocate non-debug sections at the moment
3129 if (strncmp(section_name, debug_prefix, strlen(debug_prefix)))
3130 return;
3131
3132 // Relocation section names to look for
3133 std::string needle = std::string(".rel") + section_name;
3134 std::string needlea = std::string(".rela") + section_name;
3135
3136 for (SectionHeaderCollIter I = m_section_headers.begin();
3137 I != m_section_headers.end(); ++I) {
3138 if (I->sh_type == SHT_RELA || I->sh_type == SHT_REL) {
3139 const char *hay_name = I->section_name.GetCString();
3140 if (hay_name == nullptr)
3141 continue;
3142 if (needle == hay_name || needlea == hay_name) {
3143 const ELFSectionHeader &reloc_header = *I;
3144 user_id_t reloc_id = SectionIndex(I);
3145 RelocateDebugSections(&reloc_header, reloc_id, GetSymtab());
3146 break;
3147 }
3148 }
3149 }
3150 }
3151
ParseUnwindSymbols(Symtab * symbol_table,DWARFCallFrameInfo * eh_frame)3152 void ObjectFileELF::ParseUnwindSymbols(Symtab *symbol_table,
3153 DWARFCallFrameInfo *eh_frame) {
3154 SectionList *section_list = GetSectionList();
3155 if (!section_list)
3156 return;
3157
3158 // First we save the new symbols into a separate list and add them to the
3159 // symbol table after we collected all symbols we want to add. This is
3160 // neccessary because adding a new symbol invalidates the internal index of
3161 // the symtab what causing the next lookup to be slow because it have to
3162 // recalculate the index first.
3163 std::vector<Symbol> new_symbols;
3164
3165 size_t num_symbols = symbol_table->GetNumSymbols();
3166 uint64_t last_symbol_id =
3167 num_symbols ? symbol_table->SymbolAtIndex(num_symbols - 1)->GetID() : 0;
3168 eh_frame->ForEachFDEEntries([&](lldb::addr_t file_addr, uint32_t size,
3169 dw_offset_t) {
3170 Symbol *symbol = symbol_table->FindSymbolAtFileAddress(file_addr);
3171 if (symbol) {
3172 if (!symbol->GetByteSizeIsValid()) {
3173 symbol->SetByteSize(size);
3174 symbol->SetSizeIsSynthesized(true);
3175 }
3176 } else {
3177 SectionSP section_sp =
3178 section_list->FindSectionContainingFileAddress(file_addr);
3179 if (section_sp) {
3180 addr_t offset = file_addr - section_sp->GetFileAddress();
3181 uint64_t symbol_id = ++last_symbol_id;
3182 // Don't set the name for any synthetic symbols, the Symbol
3183 // object will generate one if needed when the name is accessed
3184 // via accessors.
3185 Symbol eh_symbol(
3186 /*symID=*/symbol_id,
3187 /*name=*/llvm::StringRef(), // Name will be auto generated.
3188 /*type=*/eSymbolTypeCode,
3189 /*external=*/true,
3190 /*is_debug=*/false,
3191 /*is_trampoline=*/false,
3192 /*is_artificial=*/true,
3193 /*section_sp=*/section_sp,
3194 /*offset=*/offset,
3195 /*size=*/0, // FDE can span multiple symbols so don't use its size.
3196 /*size_is_valid=*/false,
3197 /*contains_linker_annotations=*/false,
3198 /*flags=*/0);
3199 new_symbols.push_back(eh_symbol);
3200 }
3201 }
3202 return true;
3203 });
3204
3205 for (const Symbol &s : new_symbols)
3206 symbol_table->AddSymbol(s);
3207 }
3208
IsStripped()3209 bool ObjectFileELF::IsStripped() {
3210 // TODO: determine this for ELF
3211 return false;
3212 }
3213
3214 //===----------------------------------------------------------------------===//
3215 // Dump
3216 //
3217 // Dump the specifics of the runtime file container (such as any headers
3218 // segments, sections, etc).
Dump(Stream * s)3219 void ObjectFileELF::Dump(Stream *s) {
3220 ModuleSP module_sp(GetModule());
3221 if (!module_sp) {
3222 return;
3223 }
3224
3225 std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
3226 s->Printf("%p: ", static_cast<void *>(this));
3227 s->Indent();
3228 s->PutCString("ObjectFileELF");
3229
3230 ArchSpec header_arch = GetArchitecture();
3231
3232 *s << ", file = '" << m_file
3233 << "', arch = " << header_arch.GetArchitectureName() << "\n";
3234
3235 DumpELFHeader(s, m_header);
3236 s->EOL();
3237 DumpELFProgramHeaders(s);
3238 s->EOL();
3239 DumpELFSectionHeaders(s);
3240 s->EOL();
3241 SectionList *section_list = GetSectionList();
3242 if (section_list)
3243 section_list->Dump(s->AsRawOstream(), s->GetIndentLevel(), nullptr, true,
3244 UINT32_MAX);
3245 Symtab *symtab = GetSymtab();
3246 if (symtab)
3247 symtab->Dump(s, nullptr, eSortOrderNone);
3248 s->EOL();
3249 DumpDependentModules(s);
3250 s->EOL();
3251 }
3252
3253 // DumpELFHeader
3254 //
3255 // Dump the ELF header to the specified output stream
DumpELFHeader(Stream * s,const ELFHeader & header)3256 void ObjectFileELF::DumpELFHeader(Stream *s, const ELFHeader &header) {
3257 s->PutCString("ELF Header\n");
3258 s->Printf("e_ident[EI_MAG0 ] = 0x%2.2x\n", header.e_ident[EI_MAG0]);
3259 s->Printf("e_ident[EI_MAG1 ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG1],
3260 header.e_ident[EI_MAG1]);
3261 s->Printf("e_ident[EI_MAG2 ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG2],
3262 header.e_ident[EI_MAG2]);
3263 s->Printf("e_ident[EI_MAG3 ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG3],
3264 header.e_ident[EI_MAG3]);
3265
3266 s->Printf("e_ident[EI_CLASS ] = 0x%2.2x\n", header.e_ident[EI_CLASS]);
3267 s->Printf("e_ident[EI_DATA ] = 0x%2.2x ", header.e_ident[EI_DATA]);
3268 DumpELFHeader_e_ident_EI_DATA(s, header.e_ident[EI_DATA]);
3269 s->Printf("\ne_ident[EI_VERSION] = 0x%2.2x\n", header.e_ident[EI_VERSION]);
3270 s->Printf("e_ident[EI_PAD ] = 0x%2.2x\n", header.e_ident[EI_PAD]);
3271
3272 s->Printf("e_type = 0x%4.4x ", header.e_type);
3273 DumpELFHeader_e_type(s, header.e_type);
3274 s->Printf("\ne_machine = 0x%4.4x\n", header.e_machine);
3275 s->Printf("e_version = 0x%8.8x\n", header.e_version);
3276 s->Printf("e_entry = 0x%8.8" PRIx64 "\n", header.e_entry);
3277 s->Printf("e_phoff = 0x%8.8" PRIx64 "\n", header.e_phoff);
3278 s->Printf("e_shoff = 0x%8.8" PRIx64 "\n", header.e_shoff);
3279 s->Printf("e_flags = 0x%8.8x\n", header.e_flags);
3280 s->Printf("e_ehsize = 0x%4.4x\n", header.e_ehsize);
3281 s->Printf("e_phentsize = 0x%4.4x\n", header.e_phentsize);
3282 s->Printf("e_phnum = 0x%8.8x\n", header.e_phnum);
3283 s->Printf("e_shentsize = 0x%4.4x\n", header.e_shentsize);
3284 s->Printf("e_shnum = 0x%8.8x\n", header.e_shnum);
3285 s->Printf("e_shstrndx = 0x%8.8x\n", header.e_shstrndx);
3286 }
3287
3288 // DumpELFHeader_e_type
3289 //
3290 // Dump an token value for the ELF header member e_type
DumpELFHeader_e_type(Stream * s,elf_half e_type)3291 void ObjectFileELF::DumpELFHeader_e_type(Stream *s, elf_half e_type) {
3292 switch (e_type) {
3293 case ET_NONE:
3294 *s << "ET_NONE";
3295 break;
3296 case ET_REL:
3297 *s << "ET_REL";
3298 break;
3299 case ET_EXEC:
3300 *s << "ET_EXEC";
3301 break;
3302 case ET_DYN:
3303 *s << "ET_DYN";
3304 break;
3305 case ET_CORE:
3306 *s << "ET_CORE";
3307 break;
3308 default:
3309 break;
3310 }
3311 }
3312
3313 // DumpELFHeader_e_ident_EI_DATA
3314 //
3315 // Dump an token value for the ELF header member e_ident[EI_DATA]
DumpELFHeader_e_ident_EI_DATA(Stream * s,unsigned char ei_data)3316 void ObjectFileELF::DumpELFHeader_e_ident_EI_DATA(Stream *s,
3317 unsigned char ei_data) {
3318 switch (ei_data) {
3319 case ELFDATANONE:
3320 *s << "ELFDATANONE";
3321 break;
3322 case ELFDATA2LSB:
3323 *s << "ELFDATA2LSB - Little Endian";
3324 break;
3325 case ELFDATA2MSB:
3326 *s << "ELFDATA2MSB - Big Endian";
3327 break;
3328 default:
3329 break;
3330 }
3331 }
3332
3333 // DumpELFProgramHeader
3334 //
3335 // Dump a single ELF program header to the specified output stream
DumpELFProgramHeader(Stream * s,const ELFProgramHeader & ph)3336 void ObjectFileELF::DumpELFProgramHeader(Stream *s,
3337 const ELFProgramHeader &ph) {
3338 DumpELFProgramHeader_p_type(s, ph.p_type);
3339 s->Printf(" %8.8" PRIx64 " %8.8" PRIx64 " %8.8" PRIx64, ph.p_offset,
3340 ph.p_vaddr, ph.p_paddr);
3341 s->Printf(" %8.8" PRIx64 " %8.8" PRIx64 " %8.8x (", ph.p_filesz, ph.p_memsz,
3342 ph.p_flags);
3343
3344 DumpELFProgramHeader_p_flags(s, ph.p_flags);
3345 s->Printf(") %8.8" PRIx64, ph.p_align);
3346 }
3347
3348 // DumpELFProgramHeader_p_type
3349 //
3350 // Dump an token value for the ELF program header member p_type which describes
3351 // the type of the program header
DumpELFProgramHeader_p_type(Stream * s,elf_word p_type)3352 void ObjectFileELF::DumpELFProgramHeader_p_type(Stream *s, elf_word p_type) {
3353 const int kStrWidth = 15;
3354 switch (p_type) {
3355 CASE_AND_STREAM(s, PT_NULL, kStrWidth);
3356 CASE_AND_STREAM(s, PT_LOAD, kStrWidth);
3357 CASE_AND_STREAM(s, PT_DYNAMIC, kStrWidth);
3358 CASE_AND_STREAM(s, PT_INTERP, kStrWidth);
3359 CASE_AND_STREAM(s, PT_NOTE, kStrWidth);
3360 CASE_AND_STREAM(s, PT_SHLIB, kStrWidth);
3361 CASE_AND_STREAM(s, PT_PHDR, kStrWidth);
3362 CASE_AND_STREAM(s, PT_TLS, kStrWidth);
3363 CASE_AND_STREAM(s, PT_GNU_EH_FRAME, kStrWidth);
3364 default:
3365 s->Printf("0x%8.8x%*s", p_type, kStrWidth - 10, "");
3366 break;
3367 }
3368 }
3369
3370 // DumpELFProgramHeader_p_flags
3371 //
3372 // Dump an token value for the ELF program header member p_flags
DumpELFProgramHeader_p_flags(Stream * s,elf_word p_flags)3373 void ObjectFileELF::DumpELFProgramHeader_p_flags(Stream *s, elf_word p_flags) {
3374 *s << ((p_flags & PF_X) ? "PF_X" : " ")
3375 << (((p_flags & PF_X) && (p_flags & PF_W)) ? '+' : ' ')
3376 << ((p_flags & PF_W) ? "PF_W" : " ")
3377 << (((p_flags & PF_W) && (p_flags & PF_R)) ? '+' : ' ')
3378 << ((p_flags & PF_R) ? "PF_R" : " ");
3379 }
3380
3381 // DumpELFProgramHeaders
3382 //
3383 // Dump all of the ELF program header to the specified output stream
DumpELFProgramHeaders(Stream * s)3384 void ObjectFileELF::DumpELFProgramHeaders(Stream *s) {
3385 if (!ParseProgramHeaders())
3386 return;
3387
3388 s->PutCString("Program Headers\n");
3389 s->PutCString("IDX p_type p_offset p_vaddr p_paddr "
3390 "p_filesz p_memsz p_flags p_align\n");
3391 s->PutCString("==== --------------- -------- -------- -------- "
3392 "-------- -------- ------------------------- --------\n");
3393
3394 for (const auto &H : llvm::enumerate(m_program_headers)) {
3395 s->Format("[{0,2}] ", H.index());
3396 ObjectFileELF::DumpELFProgramHeader(s, H.value());
3397 s->EOL();
3398 }
3399 }
3400
3401 // DumpELFSectionHeader
3402 //
3403 // Dump a single ELF section header to the specified output stream
DumpELFSectionHeader(Stream * s,const ELFSectionHeaderInfo & sh)3404 void ObjectFileELF::DumpELFSectionHeader(Stream *s,
3405 const ELFSectionHeaderInfo &sh) {
3406 s->Printf("%8.8x ", sh.sh_name);
3407 DumpELFSectionHeader_sh_type(s, sh.sh_type);
3408 s->Printf(" %8.8" PRIx64 " (", sh.sh_flags);
3409 DumpELFSectionHeader_sh_flags(s, sh.sh_flags);
3410 s->Printf(") %8.8" PRIx64 " %8.8" PRIx64 " %8.8" PRIx64, sh.sh_addr,
3411 sh.sh_offset, sh.sh_size);
3412 s->Printf(" %8.8x %8.8x", sh.sh_link, sh.sh_info);
3413 s->Printf(" %8.8" PRIx64 " %8.8" PRIx64, sh.sh_addralign, sh.sh_entsize);
3414 }
3415
3416 // DumpELFSectionHeader_sh_type
3417 //
3418 // Dump an token value for the ELF section header member sh_type which
3419 // describes the type of the section
DumpELFSectionHeader_sh_type(Stream * s,elf_word sh_type)3420 void ObjectFileELF::DumpELFSectionHeader_sh_type(Stream *s, elf_word sh_type) {
3421 const int kStrWidth = 12;
3422 switch (sh_type) {
3423 CASE_AND_STREAM(s, SHT_NULL, kStrWidth);
3424 CASE_AND_STREAM(s, SHT_PROGBITS, kStrWidth);
3425 CASE_AND_STREAM(s, SHT_SYMTAB, kStrWidth);
3426 CASE_AND_STREAM(s, SHT_STRTAB, kStrWidth);
3427 CASE_AND_STREAM(s, SHT_RELA, kStrWidth);
3428 CASE_AND_STREAM(s, SHT_HASH, kStrWidth);
3429 CASE_AND_STREAM(s, SHT_DYNAMIC, kStrWidth);
3430 CASE_AND_STREAM(s, SHT_NOTE, kStrWidth);
3431 CASE_AND_STREAM(s, SHT_NOBITS, kStrWidth);
3432 CASE_AND_STREAM(s, SHT_REL, kStrWidth);
3433 CASE_AND_STREAM(s, SHT_SHLIB, kStrWidth);
3434 CASE_AND_STREAM(s, SHT_DYNSYM, kStrWidth);
3435 CASE_AND_STREAM(s, SHT_LOPROC, kStrWidth);
3436 CASE_AND_STREAM(s, SHT_HIPROC, kStrWidth);
3437 CASE_AND_STREAM(s, SHT_LOUSER, kStrWidth);
3438 CASE_AND_STREAM(s, SHT_HIUSER, kStrWidth);
3439 default:
3440 s->Printf("0x%8.8x%*s", sh_type, kStrWidth - 10, "");
3441 break;
3442 }
3443 }
3444
3445 // DumpELFSectionHeader_sh_flags
3446 //
3447 // Dump an token value for the ELF section header member sh_flags
DumpELFSectionHeader_sh_flags(Stream * s,elf_xword sh_flags)3448 void ObjectFileELF::DumpELFSectionHeader_sh_flags(Stream *s,
3449 elf_xword sh_flags) {
3450 *s << ((sh_flags & SHF_WRITE) ? "WRITE" : " ")
3451 << (((sh_flags & SHF_WRITE) && (sh_flags & SHF_ALLOC)) ? '+' : ' ')
3452 << ((sh_flags & SHF_ALLOC) ? "ALLOC" : " ")
3453 << (((sh_flags & SHF_ALLOC) && (sh_flags & SHF_EXECINSTR)) ? '+' : ' ')
3454 << ((sh_flags & SHF_EXECINSTR) ? "EXECINSTR" : " ");
3455 }
3456
3457 // DumpELFSectionHeaders
3458 //
3459 // Dump all of the ELF section header to the specified output stream
DumpELFSectionHeaders(Stream * s)3460 void ObjectFileELF::DumpELFSectionHeaders(Stream *s) {
3461 if (!ParseSectionHeaders())
3462 return;
3463
3464 s->PutCString("Section Headers\n");
3465 s->PutCString("IDX name type flags "
3466 "addr offset size link info addralgn "
3467 "entsize Name\n");
3468 s->PutCString("==== -------- ------------ -------------------------------- "
3469 "-------- -------- -------- -------- -------- -------- "
3470 "-------- ====================\n");
3471
3472 uint32_t idx = 0;
3473 for (SectionHeaderCollConstIter I = m_section_headers.begin();
3474 I != m_section_headers.end(); ++I, ++idx) {
3475 s->Printf("[%2u] ", idx);
3476 ObjectFileELF::DumpELFSectionHeader(s, *I);
3477 const char *section_name = I->section_name.AsCString("");
3478 if (section_name)
3479 *s << ' ' << section_name << "\n";
3480 }
3481 }
3482
DumpDependentModules(lldb_private::Stream * s)3483 void ObjectFileELF::DumpDependentModules(lldb_private::Stream *s) {
3484 size_t num_modules = ParseDependentModules();
3485
3486 if (num_modules > 0) {
3487 s->PutCString("Dependent Modules:\n");
3488 for (unsigned i = 0; i < num_modules; ++i) {
3489 const FileSpec &spec = m_filespec_up->GetFileSpecAtIndex(i);
3490 s->Printf(" %s\n", spec.GetFilename().GetCString());
3491 }
3492 }
3493 }
3494
GetArchitecture()3495 ArchSpec ObjectFileELF::GetArchitecture() {
3496 if (!ParseHeader())
3497 return ArchSpec();
3498
3499 if (m_section_headers.empty()) {
3500 // Allow elf notes to be parsed which may affect the detected architecture.
3501 ParseSectionHeaders();
3502 }
3503
3504 if (CalculateType() == eTypeCoreFile &&
3505 !m_arch_spec.TripleOSWasSpecified()) {
3506 // Core files don't have section headers yet they have PT_NOTE program
3507 // headers that might shed more light on the architecture
3508 for (const elf::ELFProgramHeader &H : ProgramHeaders()) {
3509 if (H.p_type != PT_NOTE || H.p_offset == 0 || H.p_filesz == 0)
3510 continue;
3511 DataExtractor data;
3512 if (data.SetData(m_data, H.p_offset, H.p_filesz) == H.p_filesz) {
3513 UUID uuid;
3514 RefineModuleDetailsFromNote(data, m_arch_spec, uuid);
3515 }
3516 }
3517 }
3518 return m_arch_spec;
3519 }
3520
CalculateType()3521 ObjectFile::Type ObjectFileELF::CalculateType() {
3522 switch (m_header.e_type) {
3523 case llvm::ELF::ET_NONE:
3524 // 0 - No file type
3525 return eTypeUnknown;
3526
3527 case llvm::ELF::ET_REL:
3528 // 1 - Relocatable file
3529 return eTypeObjectFile;
3530
3531 case llvm::ELF::ET_EXEC:
3532 // 2 - Executable file
3533 return eTypeExecutable;
3534
3535 case llvm::ELF::ET_DYN:
3536 // 3 - Shared object file
3537 return eTypeSharedLibrary;
3538
3539 case ET_CORE:
3540 // 4 - Core file
3541 return eTypeCoreFile;
3542
3543 default:
3544 break;
3545 }
3546 return eTypeUnknown;
3547 }
3548
CalculateStrata()3549 ObjectFile::Strata ObjectFileELF::CalculateStrata() {
3550 switch (m_header.e_type) {
3551 case llvm::ELF::ET_NONE:
3552 // 0 - No file type
3553 return eStrataUnknown;
3554
3555 case llvm::ELF::ET_REL:
3556 // 1 - Relocatable file
3557 return eStrataUnknown;
3558
3559 case llvm::ELF::ET_EXEC:
3560 // 2 - Executable file
3561 {
3562 SectionList *section_list = GetSectionList();
3563 if (section_list) {
3564 static ConstString loader_section_name(".interp");
3565 SectionSP loader_section =
3566 section_list->FindSectionByName(loader_section_name);
3567 if (loader_section) {
3568 char buffer[256];
3569 size_t read_size =
3570 ReadSectionData(loader_section.get(), 0, buffer, sizeof(buffer));
3571
3572 // We compare the content of .interp section
3573 // It will contains \0 when counting read_size, so the size needs to
3574 // decrease by one
3575 llvm::StringRef loader_name(buffer, read_size - 1);
3576 llvm::StringRef freebsd_kernel_loader_name("/red/herring");
3577 if (loader_name == freebsd_kernel_loader_name)
3578 return eStrataKernel;
3579 }
3580 }
3581 return eStrataUser;
3582 }
3583
3584 case llvm::ELF::ET_DYN:
3585 // 3 - Shared object file
3586 // TODO: is there any way to detect that an shared library is a kernel
3587 // related executable by inspecting the program headers, section headers,
3588 // symbols, or any other flag bits???
3589 return eStrataUnknown;
3590
3591 case ET_CORE:
3592 // 4 - Core file
3593 // TODO: is there any way to detect that an core file is a kernel
3594 // related executable by inspecting the program headers, section headers,
3595 // symbols, or any other flag bits???
3596 return eStrataUnknown;
3597
3598 default:
3599 break;
3600 }
3601 return eStrataUnknown;
3602 }
3603
ReadSectionData(Section * section,lldb::offset_t section_offset,void * dst,size_t dst_len)3604 size_t ObjectFileELF::ReadSectionData(Section *section,
3605 lldb::offset_t section_offset, void *dst,
3606 size_t dst_len) {
3607 // If some other objectfile owns this data, pass this to them.
3608 if (section->GetObjectFile() != this)
3609 return section->GetObjectFile()->ReadSectionData(section, section_offset,
3610 dst, dst_len);
3611
3612 if (!section->Test(SHF_COMPRESSED))
3613 return ObjectFile::ReadSectionData(section, section_offset, dst, dst_len);
3614
3615 // For compressed sections we need to read to full data to be able to
3616 // decompress.
3617 DataExtractor data;
3618 ReadSectionData(section, data);
3619 return data.CopyData(section_offset, dst_len, dst);
3620 }
3621
ReadSectionData(Section * section,DataExtractor & section_data)3622 size_t ObjectFileELF::ReadSectionData(Section *section,
3623 DataExtractor §ion_data) {
3624 // If some other objectfile owns this data, pass this to them.
3625 if (section->GetObjectFile() != this)
3626 return section->GetObjectFile()->ReadSectionData(section, section_data);
3627
3628 size_t result = ObjectFile::ReadSectionData(section, section_data);
3629 if (result == 0 || !(section->Get() & llvm::ELF::SHF_COMPRESSED))
3630 return result;
3631
3632 auto Decompressor = llvm::object::Decompressor::create(
3633 section->GetName().GetStringRef(),
3634 {reinterpret_cast<const char *>(section_data.GetDataStart()),
3635 size_t(section_data.GetByteSize())},
3636 GetByteOrder() == eByteOrderLittle, GetAddressByteSize() == 8);
3637 if (!Decompressor) {
3638 GetModule()->ReportWarning(
3639 "Unable to initialize decompressor for section '{0}': {1}",
3640 section->GetName().GetCString(),
3641 llvm::toString(Decompressor.takeError()).c_str());
3642 section_data.Clear();
3643 return 0;
3644 }
3645
3646 auto buffer_sp =
3647 std::make_shared<DataBufferHeap>(Decompressor->getDecompressedSize(), 0);
3648 if (auto error = Decompressor->decompress(
3649 {buffer_sp->GetBytes(), size_t(buffer_sp->GetByteSize())})) {
3650 GetModule()->ReportWarning("Decompression of section '{0}' failed: {1}",
3651 section->GetName().GetCString(),
3652 llvm::toString(std::move(error)).c_str());
3653 section_data.Clear();
3654 return 0;
3655 }
3656
3657 section_data.SetData(buffer_sp);
3658 return buffer_sp->GetByteSize();
3659 }
3660
ProgramHeaders()3661 llvm::ArrayRef<ELFProgramHeader> ObjectFileELF::ProgramHeaders() {
3662 ParseProgramHeaders();
3663 return m_program_headers;
3664 }
3665
GetSegmentData(const ELFProgramHeader & H)3666 DataExtractor ObjectFileELF::GetSegmentData(const ELFProgramHeader &H) {
3667 return DataExtractor(m_data, H.p_offset, H.p_filesz);
3668 }
3669
AnySegmentHasPhysicalAddress()3670 bool ObjectFileELF::AnySegmentHasPhysicalAddress() {
3671 for (const ELFProgramHeader &H : ProgramHeaders()) {
3672 if (H.p_paddr != 0)
3673 return true;
3674 }
3675 return false;
3676 }
3677
3678 std::vector<ObjectFile::LoadableData>
GetLoadableData(Target & target)3679 ObjectFileELF::GetLoadableData(Target &target) {
3680 // Create a list of loadable data from loadable segments, using physical
3681 // addresses if they aren't all null
3682 std::vector<LoadableData> loadables;
3683 bool should_use_paddr = AnySegmentHasPhysicalAddress();
3684 for (const ELFProgramHeader &H : ProgramHeaders()) {
3685 LoadableData loadable;
3686 if (H.p_type != llvm::ELF::PT_LOAD)
3687 continue;
3688 loadable.Dest = should_use_paddr ? H.p_paddr : H.p_vaddr;
3689 if (loadable.Dest == LLDB_INVALID_ADDRESS)
3690 continue;
3691 if (H.p_filesz == 0)
3692 continue;
3693 auto segment_data = GetSegmentData(H);
3694 loadable.Contents = llvm::ArrayRef<uint8_t>(segment_data.GetDataStart(),
3695 segment_data.GetByteSize());
3696 loadables.push_back(loadable);
3697 }
3698 return loadables;
3699 }
3700
3701 lldb::WritableDataBufferSP
MapFileDataWritable(const FileSpec & file,uint64_t Size,uint64_t Offset)3702 ObjectFileELF::MapFileDataWritable(const FileSpec &file, uint64_t Size,
3703 uint64_t Offset) {
3704 return FileSystem::Instance().CreateWritableDataBuffer(file.GetPath(), Size,
3705 Offset);
3706 }
3707