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/FileSpecList.h"
17 #include "lldb/Core/Module.h"
18 #include "lldb/Core/ModuleSpec.h"
19 #include "lldb/Core/PluginManager.h"
20 #include "lldb/Core/Progress.h"
21 #include "lldb/Core/Section.h"
22 #include "lldb/Host/FileSystem.h"
23 #include "lldb/Host/LZMA.h"
24 #include "lldb/Symbol/DWARFCallFrameInfo.h"
25 #include "lldb/Symbol/SymbolContext.h"
26 #include "lldb/Target/SectionLoadList.h"
27 #include "lldb/Target/Target.h"
28 #include "lldb/Utility/ArchSpec.h"
29 #include "lldb/Utility/DataBufferHeap.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
559 const uint32_t sub_type = subTypeFromElfHeader(header);
560 spec.GetArchitecture().SetArchitecture(
561 eArchTypeELF, header.e_machine, sub_type, header.e_ident[EI_OSABI]);
562
563 if (spec.GetArchitecture().IsValid()) {
564 llvm::Triple::OSType ostype;
565 llvm::Triple::VendorType vendor;
566 llvm::Triple::OSType spec_ostype =
567 spec.GetArchitecture().GetTriple().getOS();
568
569 LLDB_LOGF(log, "ObjectFileELF::%s file '%s' module OSABI: %s",
570 __FUNCTION__, file.GetPath().c_str(),
571 OSABIAsCString(header.e_ident[EI_OSABI]));
572
573 // SetArchitecture should have set the vendor to unknown
574 vendor = spec.GetArchitecture().GetTriple().getVendor();
575 assert(vendor == llvm::Triple::UnknownVendor);
576 UNUSED_IF_ASSERT_DISABLED(vendor);
577
578 //
579 // Validate it is ok to remove GetOsFromOSABI
580 GetOsFromOSABI(header.e_ident[EI_OSABI], ostype);
581 assert(spec_ostype == ostype);
582 if (spec_ostype != llvm::Triple::OSType::UnknownOS) {
583 LLDB_LOGF(log,
584 "ObjectFileELF::%s file '%s' set ELF module OS type "
585 "from ELF header OSABI.",
586 __FUNCTION__, file.GetPath().c_str());
587 }
588
589 if (data_sp->GetByteSize() < length)
590 data_sp = MapFileData(file, -1, file_offset);
591 if (data_sp)
592 data.SetData(data_sp);
593 // In case there is header extension in the section #0, the header we
594 // parsed above could have sentinel values for e_phnum, e_shnum, and
595 // e_shstrndx. In this case we need to reparse the header with a
596 // bigger data source to get the actual values.
597 if (header.HasHeaderExtension()) {
598 lldb::offset_t header_offset = data_offset;
599 header.Parse(data, &header_offset);
600 }
601
602 uint32_t gnu_debuglink_crc = 0;
603 std::string gnu_debuglink_file;
604 SectionHeaderColl section_headers;
605 lldb_private::UUID &uuid = spec.GetUUID();
606
607 GetSectionHeaderInfo(section_headers, data, header, uuid,
608 gnu_debuglink_file, gnu_debuglink_crc,
609 spec.GetArchitecture());
610
611 llvm::Triple &spec_triple = spec.GetArchitecture().GetTriple();
612
613 LLDB_LOGF(log,
614 "ObjectFileELF::%s file '%s' module set to triple: %s "
615 "(architecture %s)",
616 __FUNCTION__, file.GetPath().c_str(),
617 spec_triple.getTriple().c_str(),
618 spec.GetArchitecture().GetArchitectureName());
619
620 if (!uuid.IsValid()) {
621 uint32_t core_notes_crc = 0;
622
623 if (!gnu_debuglink_crc) {
624 LLDB_SCOPED_TIMERF(
625 "Calculating module crc32 %s with size %" PRIu64 " KiB",
626 file.GetLastPathComponent().AsCString(),
627 (length - file_offset) / 1024);
628
629 // For core files - which usually don't happen to have a
630 // gnu_debuglink, and are pretty bulky - calculating whole
631 // contents crc32 would be too much of luxury. Thus we will need
632 // to fallback to something simpler.
633 if (header.e_type == llvm::ELF::ET_CORE) {
634 ProgramHeaderColl program_headers;
635 GetProgramHeaderInfo(program_headers, data, header);
636
637 core_notes_crc =
638 CalculateELFNotesSegmentsCRC32(program_headers, data);
639 } else {
640 gnu_debuglink_crc = calc_crc32(0, data);
641 }
642 }
643 using u32le = llvm::support::ulittle32_t;
644 if (gnu_debuglink_crc) {
645 // Use 4 bytes of crc from the .gnu_debuglink section.
646 u32le data(gnu_debuglink_crc);
647 uuid = UUID(&data, sizeof(data));
648 } else if (core_notes_crc) {
649 // Use 8 bytes - first 4 bytes for *magic* prefix, mainly to make
650 // it look different form .gnu_debuglink crc followed by 4 bytes
651 // of note segments crc.
652 u32le data[] = {u32le(g_core_uuid_magic), u32le(core_notes_crc)};
653 uuid = UUID(data, sizeof(data));
654 }
655 }
656
657 specs.Append(spec);
658 }
659 }
660 }
661 }
662
663 return specs.GetSize() - initial_count;
664 }
665
666 // ObjectFile protocol
667
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)668 ObjectFileELF::ObjectFileELF(const lldb::ModuleSP &module_sp,
669 DataBufferSP data_sp, lldb::offset_t data_offset,
670 const FileSpec *file, lldb::offset_t file_offset,
671 lldb::offset_t length)
672 : ObjectFile(module_sp, file, file_offset, length, data_sp, data_offset) {
673 if (file)
674 m_file = *file;
675 }
676
ObjectFileELF(const lldb::ModuleSP & module_sp,DataBufferSP header_data_sp,const lldb::ProcessSP & process_sp,addr_t header_addr)677 ObjectFileELF::ObjectFileELF(const lldb::ModuleSP &module_sp,
678 DataBufferSP header_data_sp,
679 const lldb::ProcessSP &process_sp,
680 addr_t header_addr)
681 : ObjectFile(module_sp, process_sp, header_addr, header_data_sp) {}
682
IsExecutable() const683 bool ObjectFileELF::IsExecutable() const {
684 return ((m_header.e_type & ET_EXEC) != 0) || (m_header.e_entry != 0);
685 }
686
SetLoadAddress(Target & target,lldb::addr_t value,bool value_is_offset)687 bool ObjectFileELF::SetLoadAddress(Target &target, lldb::addr_t value,
688 bool value_is_offset) {
689 ModuleSP module_sp = GetModule();
690 if (module_sp) {
691 size_t num_loaded_sections = 0;
692 SectionList *section_list = GetSectionList();
693 if (section_list) {
694 if (!value_is_offset) {
695 addr_t base = GetBaseAddress().GetFileAddress();
696 if (base == LLDB_INVALID_ADDRESS)
697 return false;
698 value -= base;
699 }
700
701 const size_t num_sections = section_list->GetSize();
702 size_t sect_idx = 0;
703
704 for (sect_idx = 0; sect_idx < num_sections; ++sect_idx) {
705 // Iterate through the object file sections to find all of the sections
706 // that have SHF_ALLOC in their flag bits.
707 SectionSP section_sp(section_list->GetSectionAtIndex(sect_idx));
708 if (section_sp->Test(SHF_ALLOC) ||
709 section_sp->GetType() == eSectionTypeContainer) {
710 lldb::addr_t load_addr = section_sp->GetFileAddress();
711 // We don't want to update the load address of a section with type
712 // eSectionTypeAbsoluteAddress as they already have the absolute load
713 // address already specified
714 if (section_sp->GetType() != eSectionTypeAbsoluteAddress)
715 load_addr += value;
716
717 // On 32-bit systems the load address have to fit into 4 bytes. The
718 // rest of the bytes are the overflow from the addition.
719 if (GetAddressByteSize() == 4)
720 load_addr &= 0xFFFFFFFF;
721
722 if (target.GetSectionLoadList().SetSectionLoadAddress(section_sp,
723 load_addr))
724 ++num_loaded_sections;
725 }
726 }
727 return num_loaded_sections > 0;
728 }
729 }
730 return false;
731 }
732
GetByteOrder() const733 ByteOrder ObjectFileELF::GetByteOrder() const {
734 if (m_header.e_ident[EI_DATA] == ELFDATA2MSB)
735 return eByteOrderBig;
736 if (m_header.e_ident[EI_DATA] == ELFDATA2LSB)
737 return eByteOrderLittle;
738 return eByteOrderInvalid;
739 }
740
GetAddressByteSize() const741 uint32_t ObjectFileELF::GetAddressByteSize() const {
742 return m_data.GetAddressByteSize();
743 }
744
GetAddressClass(addr_t file_addr)745 AddressClass ObjectFileELF::GetAddressClass(addr_t file_addr) {
746 Symtab *symtab = GetSymtab();
747 if (!symtab)
748 return AddressClass::eUnknown;
749
750 // The address class is determined based on the symtab. Ask it from the
751 // object file what contains the symtab information.
752 ObjectFile *symtab_objfile = symtab->GetObjectFile();
753 if (symtab_objfile != nullptr && symtab_objfile != this)
754 return symtab_objfile->GetAddressClass(file_addr);
755
756 auto res = ObjectFile::GetAddressClass(file_addr);
757 if (res != AddressClass::eCode)
758 return res;
759
760 auto ub = m_address_class_map.upper_bound(file_addr);
761 if (ub == m_address_class_map.begin()) {
762 // No entry in the address class map before the address. Return default
763 // address class for an address in a code section.
764 return AddressClass::eCode;
765 }
766
767 // Move iterator to the address class entry preceding address
768 --ub;
769
770 return ub->second;
771 }
772
SectionIndex(const SectionHeaderCollIter & I)773 size_t ObjectFileELF::SectionIndex(const SectionHeaderCollIter &I) {
774 return std::distance(m_section_headers.begin(), I);
775 }
776
SectionIndex(const SectionHeaderCollConstIter & I) const777 size_t ObjectFileELF::SectionIndex(const SectionHeaderCollConstIter &I) const {
778 return std::distance(m_section_headers.begin(), I);
779 }
780
ParseHeader()781 bool ObjectFileELF::ParseHeader() {
782 lldb::offset_t offset = 0;
783 return m_header.Parse(m_data, &offset);
784 }
785
GetUUID()786 UUID ObjectFileELF::GetUUID() {
787 // Need to parse the section list to get the UUIDs, so make sure that's been
788 // done.
789 if (!ParseSectionHeaders() && GetType() != ObjectFile::eTypeCoreFile)
790 return UUID();
791
792 if (!m_uuid) {
793 using u32le = llvm::support::ulittle32_t;
794 if (GetType() == ObjectFile::eTypeCoreFile) {
795 uint32_t core_notes_crc = 0;
796
797 if (!ParseProgramHeaders())
798 return UUID();
799
800 core_notes_crc =
801 CalculateELFNotesSegmentsCRC32(m_program_headers, m_data);
802
803 if (core_notes_crc) {
804 // Use 8 bytes - first 4 bytes for *magic* prefix, mainly to make it
805 // look different form .gnu_debuglink crc - followed by 4 bytes of note
806 // segments crc.
807 u32le data[] = {u32le(g_core_uuid_magic), u32le(core_notes_crc)};
808 m_uuid = UUID(data, sizeof(data));
809 }
810 } else {
811 if (!m_gnu_debuglink_crc)
812 m_gnu_debuglink_crc = calc_crc32(0, m_data);
813 if (m_gnu_debuglink_crc) {
814 // Use 4 bytes of crc from the .gnu_debuglink section.
815 u32le data(m_gnu_debuglink_crc);
816 m_uuid = UUID(&data, sizeof(data));
817 }
818 }
819 }
820
821 return m_uuid;
822 }
823
GetDebugLink()824 std::optional<FileSpec> ObjectFileELF::GetDebugLink() {
825 if (m_gnu_debuglink_file.empty())
826 return std::nullopt;
827 return FileSpec(m_gnu_debuglink_file);
828 }
829
GetDependentModules(FileSpecList & files)830 uint32_t ObjectFileELF::GetDependentModules(FileSpecList &files) {
831 size_t num_modules = ParseDependentModules();
832 uint32_t num_specs = 0;
833
834 for (unsigned i = 0; i < num_modules; ++i) {
835 if (files.AppendIfUnique(m_filespec_up->GetFileSpecAtIndex(i)))
836 num_specs++;
837 }
838
839 return num_specs;
840 }
841
GetImageInfoAddress(Target * target)842 Address ObjectFileELF::GetImageInfoAddress(Target *target) {
843 if (!ParseDynamicSymbols())
844 return Address();
845
846 SectionList *section_list = GetSectionList();
847 if (!section_list)
848 return Address();
849
850 // Find the SHT_DYNAMIC (.dynamic) section.
851 SectionSP dynsym_section_sp(
852 section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true));
853 if (!dynsym_section_sp)
854 return Address();
855 assert(dynsym_section_sp->GetObjectFile() == this);
856
857 user_id_t dynsym_id = dynsym_section_sp->GetID();
858 const ELFSectionHeaderInfo *dynsym_hdr = GetSectionHeaderByIndex(dynsym_id);
859 if (!dynsym_hdr)
860 return Address();
861
862 for (size_t i = 0; i < m_dynamic_symbols.size(); ++i) {
863 ELFDynamic &symbol = m_dynamic_symbols[i];
864
865 if (symbol.d_tag == DT_DEBUG) {
866 // Compute the offset as the number of previous entries plus the size of
867 // d_tag.
868 addr_t offset = i * dynsym_hdr->sh_entsize + GetAddressByteSize();
869 return Address(dynsym_section_sp, offset);
870 }
871 // MIPS executables uses DT_MIPS_RLD_MAP_REL to support PIE. DT_MIPS_RLD_MAP
872 // exists in non-PIE.
873 else if ((symbol.d_tag == DT_MIPS_RLD_MAP ||
874 symbol.d_tag == DT_MIPS_RLD_MAP_REL) &&
875 target) {
876 addr_t offset = i * dynsym_hdr->sh_entsize + GetAddressByteSize();
877 addr_t dyn_base = dynsym_section_sp->GetLoadBaseAddress(target);
878 if (dyn_base == LLDB_INVALID_ADDRESS)
879 return Address();
880
881 Status error;
882 if (symbol.d_tag == DT_MIPS_RLD_MAP) {
883 // DT_MIPS_RLD_MAP tag stores an absolute address of the debug pointer.
884 Address addr;
885 if (target->ReadPointerFromMemory(dyn_base + offset, error, addr, true))
886 return addr;
887 }
888 if (symbol.d_tag == DT_MIPS_RLD_MAP_REL) {
889 // DT_MIPS_RLD_MAP_REL tag stores the offset to the debug pointer,
890 // relative to the address of the tag.
891 uint64_t rel_offset;
892 rel_offset = target->ReadUnsignedIntegerFromMemory(
893 dyn_base + offset, GetAddressByteSize(), UINT64_MAX, error, true);
894 if (error.Success() && rel_offset != UINT64_MAX) {
895 Address addr;
896 addr_t debug_ptr_address =
897 dyn_base + (offset - GetAddressByteSize()) + rel_offset;
898 addr.SetOffset(debug_ptr_address);
899 return addr;
900 }
901 }
902 }
903 }
904
905 return Address();
906 }
907
GetEntryPointAddress()908 lldb_private::Address ObjectFileELF::GetEntryPointAddress() {
909 if (m_entry_point_address.IsValid())
910 return m_entry_point_address;
911
912 if (!ParseHeader() || !IsExecutable())
913 return m_entry_point_address;
914
915 SectionList *section_list = GetSectionList();
916 addr_t offset = m_header.e_entry;
917
918 if (!section_list)
919 m_entry_point_address.SetOffset(offset);
920 else
921 m_entry_point_address.ResolveAddressUsingFileSections(offset, section_list);
922 return m_entry_point_address;
923 }
924
GetBaseAddress()925 Address ObjectFileELF::GetBaseAddress() {
926 for (const auto &EnumPHdr : llvm::enumerate(ProgramHeaders())) {
927 const ELFProgramHeader &H = EnumPHdr.value();
928 if (H.p_type != PT_LOAD)
929 continue;
930
931 return Address(
932 GetSectionList()->FindSectionByID(SegmentID(EnumPHdr.index())), 0);
933 }
934 return LLDB_INVALID_ADDRESS;
935 }
936
937 // ParseDependentModules
ParseDependentModules()938 size_t ObjectFileELF::ParseDependentModules() {
939 if (m_filespec_up)
940 return m_filespec_up->GetSize();
941
942 m_filespec_up = std::make_unique<FileSpecList>();
943
944 if (!ParseSectionHeaders())
945 return 0;
946
947 SectionList *section_list = GetSectionList();
948 if (!section_list)
949 return 0;
950
951 // Find the SHT_DYNAMIC section.
952 Section *dynsym =
953 section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true)
954 .get();
955 if (!dynsym)
956 return 0;
957 assert(dynsym->GetObjectFile() == this);
958
959 const ELFSectionHeaderInfo *header = GetSectionHeaderByIndex(dynsym->GetID());
960 if (!header)
961 return 0;
962 // sh_link: section header index of string table used by entries in the
963 // section.
964 Section *dynstr = section_list->FindSectionByID(header->sh_link).get();
965 if (!dynstr)
966 return 0;
967
968 DataExtractor dynsym_data;
969 DataExtractor dynstr_data;
970 if (ReadSectionData(dynsym, dynsym_data) &&
971 ReadSectionData(dynstr, dynstr_data)) {
972 ELFDynamic symbol;
973 const lldb::offset_t section_size = dynsym_data.GetByteSize();
974 lldb::offset_t offset = 0;
975
976 // The only type of entries we are concerned with are tagged DT_NEEDED,
977 // yielding the name of a required library.
978 while (offset < section_size) {
979 if (!symbol.Parse(dynsym_data, &offset))
980 break;
981
982 if (symbol.d_tag != DT_NEEDED)
983 continue;
984
985 uint32_t str_index = static_cast<uint32_t>(symbol.d_val);
986 const char *lib_name = dynstr_data.PeekCStr(str_index);
987 FileSpec file_spec(lib_name);
988 FileSystem::Instance().Resolve(file_spec);
989 m_filespec_up->Append(file_spec);
990 }
991 }
992
993 return m_filespec_up->GetSize();
994 }
995
996 // GetProgramHeaderInfo
GetProgramHeaderInfo(ProgramHeaderColl & program_headers,DataExtractor & object_data,const ELFHeader & header)997 size_t ObjectFileELF::GetProgramHeaderInfo(ProgramHeaderColl &program_headers,
998 DataExtractor &object_data,
999 const ELFHeader &header) {
1000 // We have already parsed the program headers
1001 if (!program_headers.empty())
1002 return program_headers.size();
1003
1004 // If there are no program headers to read we are done.
1005 if (header.e_phnum == 0)
1006 return 0;
1007
1008 program_headers.resize(header.e_phnum);
1009 if (program_headers.size() != header.e_phnum)
1010 return 0;
1011
1012 const size_t ph_size = header.e_phnum * header.e_phentsize;
1013 const elf_off ph_offset = header.e_phoff;
1014 DataExtractor data;
1015 if (data.SetData(object_data, ph_offset, ph_size) != ph_size)
1016 return 0;
1017
1018 uint32_t idx;
1019 lldb::offset_t offset;
1020 for (idx = 0, offset = 0; idx < header.e_phnum; ++idx) {
1021 if (!program_headers[idx].Parse(data, &offset))
1022 break;
1023 }
1024
1025 if (idx < program_headers.size())
1026 program_headers.resize(idx);
1027
1028 return program_headers.size();
1029 }
1030
1031 // ParseProgramHeaders
ParseProgramHeaders()1032 bool ObjectFileELF::ParseProgramHeaders() {
1033 return GetProgramHeaderInfo(m_program_headers, m_data, m_header) != 0;
1034 }
1035
1036 lldb_private::Status
RefineModuleDetailsFromNote(lldb_private::DataExtractor & data,lldb_private::ArchSpec & arch_spec,lldb_private::UUID & uuid)1037 ObjectFileELF::RefineModuleDetailsFromNote(lldb_private::DataExtractor &data,
1038 lldb_private::ArchSpec &arch_spec,
1039 lldb_private::UUID &uuid) {
1040 Log *log = GetLog(LLDBLog::Modules);
1041 Status error;
1042
1043 lldb::offset_t offset = 0;
1044
1045 while (true) {
1046 // Parse the note header. If this fails, bail out.
1047 const lldb::offset_t note_offset = offset;
1048 ELFNote note = ELFNote();
1049 if (!note.Parse(data, &offset)) {
1050 // We're done.
1051 return error;
1052 }
1053
1054 LLDB_LOGF(log, "ObjectFileELF::%s parsing note name='%s', type=%" PRIu32,
1055 __FUNCTION__, note.n_name.c_str(), note.n_type);
1056
1057 // Process FreeBSD ELF notes.
1058 if ((note.n_name == LLDB_NT_OWNER_FREEBSD) &&
1059 (note.n_type == LLDB_NT_FREEBSD_ABI_TAG) &&
1060 (note.n_descsz == LLDB_NT_FREEBSD_ABI_SIZE)) {
1061 // Pull out the min version info.
1062 uint32_t version_info;
1063 if (data.GetU32(&offset, &version_info, 1) == nullptr) {
1064 error.SetErrorString("failed to read FreeBSD ABI note payload");
1065 return error;
1066 }
1067
1068 // Convert the version info into a major/minor number.
1069 const uint32_t version_major = version_info / 100000;
1070 const uint32_t version_minor = (version_info / 1000) % 100;
1071
1072 char os_name[32];
1073 snprintf(os_name, sizeof(os_name), "freebsd%" PRIu32 ".%" PRIu32,
1074 version_major, version_minor);
1075
1076 // Set the elf OS version to FreeBSD. Also clear the vendor.
1077 arch_spec.GetTriple().setOSName(os_name);
1078 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1079
1080 LLDB_LOGF(log,
1081 "ObjectFileELF::%s detected FreeBSD %" PRIu32 ".%" PRIu32
1082 ".%" PRIu32,
1083 __FUNCTION__, version_major, version_minor,
1084 static_cast<uint32_t>(version_info % 1000));
1085 }
1086 // Process GNU ELF notes.
1087 else if (note.n_name == LLDB_NT_OWNER_GNU) {
1088 switch (note.n_type) {
1089 case LLDB_NT_GNU_ABI_TAG:
1090 if (note.n_descsz == LLDB_NT_GNU_ABI_SIZE) {
1091 // Pull out the min OS version supporting the ABI.
1092 uint32_t version_info[4];
1093 if (data.GetU32(&offset, &version_info[0], note.n_descsz / 4) ==
1094 nullptr) {
1095 error.SetErrorString("failed to read GNU ABI note payload");
1096 return error;
1097 }
1098
1099 // Set the OS per the OS field.
1100 switch (version_info[0]) {
1101 case LLDB_NT_GNU_ABI_OS_LINUX:
1102 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1103 arch_spec.GetTriple().setVendor(
1104 llvm::Triple::VendorType::UnknownVendor);
1105 LLDB_LOGF(log,
1106 "ObjectFileELF::%s detected Linux, min version %" PRIu32
1107 ".%" PRIu32 ".%" PRIu32,
1108 __FUNCTION__, version_info[1], version_info[2],
1109 version_info[3]);
1110 // FIXME we have the minimal version number, we could be propagating
1111 // that. version_info[1] = OS Major, version_info[2] = OS Minor,
1112 // version_info[3] = Revision.
1113 break;
1114 case LLDB_NT_GNU_ABI_OS_HURD:
1115 arch_spec.GetTriple().setOS(llvm::Triple::OSType::UnknownOS);
1116 arch_spec.GetTriple().setVendor(
1117 llvm::Triple::VendorType::UnknownVendor);
1118 LLDB_LOGF(log,
1119 "ObjectFileELF::%s detected Hurd (unsupported), min "
1120 "version %" PRIu32 ".%" PRIu32 ".%" PRIu32,
1121 __FUNCTION__, version_info[1], version_info[2],
1122 version_info[3]);
1123 break;
1124 case LLDB_NT_GNU_ABI_OS_SOLARIS:
1125 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Solaris);
1126 arch_spec.GetTriple().setVendor(
1127 llvm::Triple::VendorType::UnknownVendor);
1128 LLDB_LOGF(log,
1129 "ObjectFileELF::%s detected Solaris, min version %" PRIu32
1130 ".%" PRIu32 ".%" PRIu32,
1131 __FUNCTION__, version_info[1], version_info[2],
1132 version_info[3]);
1133 break;
1134 default:
1135 LLDB_LOGF(log,
1136 "ObjectFileELF::%s unrecognized OS in note, id %" PRIu32
1137 ", min version %" PRIu32 ".%" PRIu32 ".%" PRIu32,
1138 __FUNCTION__, version_info[0], version_info[1],
1139 version_info[2], version_info[3]);
1140 break;
1141 }
1142 }
1143 break;
1144
1145 case LLDB_NT_GNU_BUILD_ID_TAG:
1146 // Only bother processing this if we don't already have the uuid set.
1147 if (!uuid.IsValid()) {
1148 // 16 bytes is UUID|MD5, 20 bytes is SHA1. Other linkers may produce a
1149 // build-id of a different length. Accept it as long as it's at least
1150 // 4 bytes as it will be better than our own crc32.
1151 if (note.n_descsz >= 4) {
1152 if (const uint8_t *buf = data.PeekData(offset, note.n_descsz)) {
1153 // Save the build id as the UUID for the module.
1154 uuid = UUID(buf, note.n_descsz);
1155 } else {
1156 error.SetErrorString("failed to read GNU_BUILD_ID note payload");
1157 return error;
1158 }
1159 }
1160 }
1161 break;
1162 }
1163 if (arch_spec.IsMIPS() &&
1164 arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS)
1165 // The note.n_name == LLDB_NT_OWNER_GNU is valid for Linux platform
1166 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1167 }
1168 // Process NetBSD ELF executables and shared libraries
1169 else if ((note.n_name == LLDB_NT_OWNER_NETBSD) &&
1170 (note.n_type == LLDB_NT_NETBSD_IDENT_TAG) &&
1171 (note.n_descsz == LLDB_NT_NETBSD_IDENT_DESCSZ) &&
1172 (note.n_namesz == LLDB_NT_NETBSD_IDENT_NAMESZ)) {
1173 // Pull out the version info.
1174 uint32_t version_info;
1175 if (data.GetU32(&offset, &version_info, 1) == nullptr) {
1176 error.SetErrorString("failed to read NetBSD ABI note payload");
1177 return error;
1178 }
1179 // Convert the version info into a major/minor/patch number.
1180 // #define __NetBSD_Version__ MMmmrrpp00
1181 //
1182 // M = major version
1183 // m = minor version; a minor number of 99 indicates current.
1184 // r = 0 (since NetBSD 3.0 not used)
1185 // p = patchlevel
1186 const uint32_t version_major = version_info / 100000000;
1187 const uint32_t version_minor = (version_info % 100000000) / 1000000;
1188 const uint32_t version_patch = (version_info % 10000) / 100;
1189 // Set the elf OS version to NetBSD. Also clear the vendor.
1190 arch_spec.GetTriple().setOSName(
1191 llvm::formatv("netbsd{0}.{1}.{2}", version_major, version_minor,
1192 version_patch).str());
1193 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1194 }
1195 // Process NetBSD ELF core(5) notes
1196 else if ((note.n_name == LLDB_NT_OWNER_NETBSDCORE) &&
1197 (note.n_type == LLDB_NT_NETBSD_PROCINFO)) {
1198 // Set the elf OS version to NetBSD. Also clear the vendor.
1199 arch_spec.GetTriple().setOS(llvm::Triple::OSType::NetBSD);
1200 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1201 }
1202 // Process OpenBSD ELF notes.
1203 else if (note.n_name == LLDB_NT_OWNER_OPENBSD) {
1204 // Set the elf OS version to OpenBSD. Also clear the vendor.
1205 arch_spec.GetTriple().setOS(llvm::Triple::OSType::OpenBSD);
1206 arch_spec.GetTriple().setVendor(llvm::Triple::VendorType::UnknownVendor);
1207 } else if (note.n_name == LLDB_NT_OWNER_ANDROID) {
1208 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1209 arch_spec.GetTriple().setEnvironment(
1210 llvm::Triple::EnvironmentType::Android);
1211 } else if (note.n_name == LLDB_NT_OWNER_LINUX) {
1212 // This is sometimes found in core files and usually contains extended
1213 // register info
1214 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1215 } else if (note.n_name == LLDB_NT_OWNER_CORE) {
1216 // Parse the NT_FILE to look for stuff in paths to shared libraries
1217 // The contents look like this in a 64 bit ELF core file:
1218 //
1219 // count = 0x000000000000000a (10)
1220 // page_size = 0x0000000000001000 (4096)
1221 // Index start end file_ofs path
1222 // ===== ------------------ ------------------ ------------------ -------------------------------------
1223 // [ 0] 0x0000000000401000 0x0000000000000000 /tmp/a.out
1224 // [ 1] 0x0000000000600000 0x0000000000601000 0x0000000000000000 /tmp/a.out
1225 // [ 2] 0x0000000000601000 0x0000000000602000 0x0000000000000001 /tmp/a.out
1226 // [ 3] 0x00007fa79c9ed000 0x00007fa79cba8000 0x0000000000000000 /lib/x86_64-linux-gnu/libc-2.19.so
1227 // [ 4] 0x00007fa79cba8000 0x00007fa79cda7000 0x00000000000001bb /lib/x86_64-linux-gnu/libc-2.19.so
1228 // [ 5] 0x00007fa79cda7000 0x00007fa79cdab000 0x00000000000001ba /lib/x86_64-linux-gnu/libc-2.19.so
1229 // [ 6] 0x00007fa79cdab000 0x00007fa79cdad000 0x00000000000001be /lib/x86_64-linux-gnu/libc-2.19.so
1230 // [ 7] 0x00007fa79cdb2000 0x00007fa79cdd5000 0x0000000000000000 /lib/x86_64-linux-gnu/ld-2.19.so
1231 // [ 8] 0x00007fa79cfd4000 0x00007fa79cfd5000 0x0000000000000022 /lib/x86_64-linux-gnu/ld-2.19.so
1232 // [ 9] 0x00007fa79cfd5000 0x00007fa79cfd6000 0x0000000000000023 /lib/x86_64-linux-gnu/ld-2.19.so
1233 //
1234 // In the 32 bit ELFs the count, page_size, start, end, file_ofs are
1235 // uint32_t.
1236 //
1237 // For reference: see readelf source code (in binutils).
1238 if (note.n_type == NT_FILE) {
1239 uint64_t count = data.GetAddress(&offset);
1240 const char *cstr;
1241 data.GetAddress(&offset); // Skip page size
1242 offset += count * 3 *
1243 data.GetAddressByteSize(); // Skip all start/end/file_ofs
1244 for (size_t i = 0; i < count; ++i) {
1245 cstr = data.GetCStr(&offset);
1246 if (cstr == nullptr) {
1247 error.SetErrorStringWithFormat("ObjectFileELF::%s trying to read "
1248 "at an offset after the end "
1249 "(GetCStr returned nullptr)",
1250 __FUNCTION__);
1251 return error;
1252 }
1253 llvm::StringRef path(cstr);
1254 if (path.contains("/lib/x86_64-linux-gnu") || path.contains("/lib/i386-linux-gnu")) {
1255 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1256 break;
1257 }
1258 }
1259 if (arch_spec.IsMIPS() &&
1260 arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS)
1261 // In case of MIPSR6, the LLDB_NT_OWNER_GNU note is missing for some
1262 // cases (e.g. compile with -nostdlib) Hence set OS to Linux
1263 arch_spec.GetTriple().setOS(llvm::Triple::OSType::Linux);
1264 }
1265 }
1266
1267 // Calculate the offset of the next note just in case "offset" has been
1268 // used to poke at the contents of the note data
1269 offset = note_offset + note.GetByteSize();
1270 }
1271
1272 return error;
1273 }
1274
ParseARMAttributes(DataExtractor & data,uint64_t length,ArchSpec & arch_spec)1275 void ObjectFileELF::ParseARMAttributes(DataExtractor &data, uint64_t length,
1276 ArchSpec &arch_spec) {
1277 lldb::offset_t Offset = 0;
1278
1279 uint8_t FormatVersion = data.GetU8(&Offset);
1280 if (FormatVersion != llvm::ELFAttrs::Format_Version)
1281 return;
1282
1283 Offset = Offset + sizeof(uint32_t); // Section Length
1284 llvm::StringRef VendorName = data.GetCStr(&Offset);
1285
1286 if (VendorName != "aeabi")
1287 return;
1288
1289 if (arch_spec.GetTriple().getEnvironment() ==
1290 llvm::Triple::UnknownEnvironment)
1291 arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
1292
1293 while (Offset < length) {
1294 uint8_t Tag = data.GetU8(&Offset);
1295 uint32_t Size = data.GetU32(&Offset);
1296
1297 if (Tag != llvm::ARMBuildAttrs::File || Size == 0)
1298 continue;
1299
1300 while (Offset < length) {
1301 uint64_t Tag = data.GetULEB128(&Offset);
1302 switch (Tag) {
1303 default:
1304 if (Tag < 32)
1305 data.GetULEB128(&Offset);
1306 else if (Tag % 2 == 0)
1307 data.GetULEB128(&Offset);
1308 else
1309 data.GetCStr(&Offset);
1310
1311 break;
1312
1313 case llvm::ARMBuildAttrs::CPU_raw_name:
1314 case llvm::ARMBuildAttrs::CPU_name:
1315 data.GetCStr(&Offset);
1316
1317 break;
1318
1319 case llvm::ARMBuildAttrs::ABI_VFP_args: {
1320 uint64_t VFPArgs = data.GetULEB128(&Offset);
1321
1322 if (VFPArgs == llvm::ARMBuildAttrs::BaseAAPCS) {
1323 if (arch_spec.GetTriple().getEnvironment() ==
1324 llvm::Triple::UnknownEnvironment ||
1325 arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABIHF)
1326 arch_spec.GetTriple().setEnvironment(llvm::Triple::EABI);
1327
1328 arch_spec.SetFlags(ArchSpec::eARM_abi_soft_float);
1329 } else if (VFPArgs == llvm::ARMBuildAttrs::HardFPAAPCS) {
1330 if (arch_spec.GetTriple().getEnvironment() ==
1331 llvm::Triple::UnknownEnvironment ||
1332 arch_spec.GetTriple().getEnvironment() == llvm::Triple::EABI)
1333 arch_spec.GetTriple().setEnvironment(llvm::Triple::EABIHF);
1334
1335 arch_spec.SetFlags(ArchSpec::eARM_abi_hard_float);
1336 }
1337
1338 break;
1339 }
1340 }
1341 }
1342 }
1343 }
1344
1345 // 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)1346 size_t ObjectFileELF::GetSectionHeaderInfo(SectionHeaderColl §ion_headers,
1347 DataExtractor &object_data,
1348 const elf::ELFHeader &header,
1349 lldb_private::UUID &uuid,
1350 std::string &gnu_debuglink_file,
1351 uint32_t &gnu_debuglink_crc,
1352 ArchSpec &arch_spec) {
1353 // Don't reparse the section headers if we already did that.
1354 if (!section_headers.empty())
1355 return section_headers.size();
1356
1357 // Only initialize the arch_spec to okay defaults if they're not already set.
1358 // We'll refine this with note data as we parse the notes.
1359 if (arch_spec.GetTriple().getOS() == llvm::Triple::OSType::UnknownOS) {
1360 llvm::Triple::OSType ostype;
1361 llvm::Triple::OSType spec_ostype;
1362 const uint32_t sub_type = subTypeFromElfHeader(header);
1363 arch_spec.SetArchitecture(eArchTypeELF, header.e_machine, sub_type,
1364 header.e_ident[EI_OSABI]);
1365
1366 // Validate if it is ok to remove GetOsFromOSABI. Note, that now the OS is
1367 // determined based on EI_OSABI flag and the info extracted from ELF notes
1368 // (see RefineModuleDetailsFromNote). However in some cases that still
1369 // might be not enough: for example a shared library might not have any
1370 // notes at all and have EI_OSABI flag set to System V, as result the OS
1371 // will be set to UnknownOS.
1372 GetOsFromOSABI(header.e_ident[EI_OSABI], ostype);
1373 spec_ostype = arch_spec.GetTriple().getOS();
1374 assert(spec_ostype == ostype);
1375 UNUSED_IF_ASSERT_DISABLED(spec_ostype);
1376 }
1377
1378 if (arch_spec.GetMachine() == llvm::Triple::mips ||
1379 arch_spec.GetMachine() == llvm::Triple::mipsel ||
1380 arch_spec.GetMachine() == llvm::Triple::mips64 ||
1381 arch_spec.GetMachine() == llvm::Triple::mips64el) {
1382 switch (header.e_flags & llvm::ELF::EF_MIPS_ARCH_ASE) {
1383 case llvm::ELF::EF_MIPS_MICROMIPS:
1384 arch_spec.SetFlags(ArchSpec::eMIPSAse_micromips);
1385 break;
1386 case llvm::ELF::EF_MIPS_ARCH_ASE_M16:
1387 arch_spec.SetFlags(ArchSpec::eMIPSAse_mips16);
1388 break;
1389 case llvm::ELF::EF_MIPS_ARCH_ASE_MDMX:
1390 arch_spec.SetFlags(ArchSpec::eMIPSAse_mdmx);
1391 break;
1392 default:
1393 break;
1394 }
1395 }
1396
1397 if (arch_spec.GetMachine() == llvm::Triple::arm ||
1398 arch_spec.GetMachine() == llvm::Triple::thumb) {
1399 if (header.e_flags & llvm::ELF::EF_ARM_SOFT_FLOAT)
1400 arch_spec.SetFlags(ArchSpec::eARM_abi_soft_float);
1401 else if (header.e_flags & llvm::ELF::EF_ARM_VFP_FLOAT)
1402 arch_spec.SetFlags(ArchSpec::eARM_abi_hard_float);
1403 }
1404
1405 if (arch_spec.GetMachine() == llvm::Triple::riscv32 ||
1406 arch_spec.GetMachine() == llvm::Triple::riscv64) {
1407 uint32_t flags = arch_spec.GetFlags();
1408
1409 if (header.e_flags & llvm::ELF::EF_RISCV_RVC)
1410 flags |= ArchSpec::eRISCV_rvc;
1411 if (header.e_flags & llvm::ELF::EF_RISCV_RVE)
1412 flags |= ArchSpec::eRISCV_rve;
1413
1414 if ((header.e_flags & llvm::ELF::EF_RISCV_FLOAT_ABI_SINGLE) ==
1415 llvm::ELF::EF_RISCV_FLOAT_ABI_SINGLE)
1416 flags |= ArchSpec::eRISCV_float_abi_single;
1417 else if ((header.e_flags & llvm::ELF::EF_RISCV_FLOAT_ABI_DOUBLE) ==
1418 llvm::ELF::EF_RISCV_FLOAT_ABI_DOUBLE)
1419 flags |= ArchSpec::eRISCV_float_abi_double;
1420 else if ((header.e_flags & llvm::ELF::EF_RISCV_FLOAT_ABI_QUAD) ==
1421 llvm::ELF::EF_RISCV_FLOAT_ABI_QUAD)
1422 flags |= ArchSpec::eRISCV_float_abi_quad;
1423
1424 arch_spec.SetFlags(flags);
1425 }
1426
1427 // If there are no section headers we are done.
1428 if (header.e_shnum == 0)
1429 return 0;
1430
1431 Log *log = GetLog(LLDBLog::Modules);
1432
1433 section_headers.resize(header.e_shnum);
1434 if (section_headers.size() != header.e_shnum)
1435 return 0;
1436
1437 const size_t sh_size = header.e_shnum * header.e_shentsize;
1438 const elf_off sh_offset = header.e_shoff;
1439 DataExtractor sh_data;
1440 if (sh_data.SetData(object_data, sh_offset, sh_size) != sh_size)
1441 return 0;
1442
1443 uint32_t idx;
1444 lldb::offset_t offset;
1445 for (idx = 0, offset = 0; idx < header.e_shnum; ++idx) {
1446 if (!section_headers[idx].Parse(sh_data, &offset))
1447 break;
1448 }
1449 if (idx < section_headers.size())
1450 section_headers.resize(idx);
1451
1452 const unsigned strtab_idx = header.e_shstrndx;
1453 if (strtab_idx && strtab_idx < section_headers.size()) {
1454 const ELFSectionHeaderInfo &sheader = section_headers[strtab_idx];
1455 const size_t byte_size = sheader.sh_size;
1456 const Elf64_Off offset = sheader.sh_offset;
1457 lldb_private::DataExtractor shstr_data;
1458
1459 if (shstr_data.SetData(object_data, offset, byte_size) == byte_size) {
1460 for (SectionHeaderCollIter I = section_headers.begin();
1461 I != section_headers.end(); ++I) {
1462 static ConstString g_sect_name_gnu_debuglink(".gnu_debuglink");
1463 const ELFSectionHeaderInfo &sheader = *I;
1464 const uint64_t section_size =
1465 sheader.sh_type == SHT_NOBITS ? 0 : sheader.sh_size;
1466 ConstString name(shstr_data.PeekCStr(I->sh_name));
1467
1468 I->section_name = name;
1469
1470 if (arch_spec.IsMIPS()) {
1471 uint32_t arch_flags = arch_spec.GetFlags();
1472 DataExtractor data;
1473 if (sheader.sh_type == SHT_MIPS_ABIFLAGS) {
1474
1475 if (section_size && (data.SetData(object_data, sheader.sh_offset,
1476 section_size) == section_size)) {
1477 // MIPS ASE Mask is at offset 12 in MIPS.abiflags section
1478 lldb::offset_t offset = 12; // MIPS ABI Flags Version: 0
1479 arch_flags |= data.GetU32(&offset);
1480
1481 // The floating point ABI is at offset 7
1482 offset = 7;
1483 switch (data.GetU8(&offset)) {
1484 case llvm::Mips::Val_GNU_MIPS_ABI_FP_ANY:
1485 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_ANY;
1486 break;
1487 case llvm::Mips::Val_GNU_MIPS_ABI_FP_DOUBLE:
1488 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_DOUBLE;
1489 break;
1490 case llvm::Mips::Val_GNU_MIPS_ABI_FP_SINGLE:
1491 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_SINGLE;
1492 break;
1493 case llvm::Mips::Val_GNU_MIPS_ABI_FP_SOFT:
1494 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_SOFT;
1495 break;
1496 case llvm::Mips::Val_GNU_MIPS_ABI_FP_OLD_64:
1497 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_OLD_64;
1498 break;
1499 case llvm::Mips::Val_GNU_MIPS_ABI_FP_XX:
1500 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_XX;
1501 break;
1502 case llvm::Mips::Val_GNU_MIPS_ABI_FP_64:
1503 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_64;
1504 break;
1505 case llvm::Mips::Val_GNU_MIPS_ABI_FP_64A:
1506 arch_flags |= lldb_private::ArchSpec::eMIPS_ABI_FP_64A;
1507 break;
1508 }
1509 }
1510 }
1511 // Settings appropriate ArchSpec ABI Flags
1512 switch (header.e_flags & llvm::ELF::EF_MIPS_ABI) {
1513 case llvm::ELF::EF_MIPS_ABI_O32:
1514 arch_flags |= lldb_private::ArchSpec::eMIPSABI_O32;
1515 break;
1516 case EF_MIPS_ABI_O64:
1517 arch_flags |= lldb_private::ArchSpec::eMIPSABI_O64;
1518 break;
1519 case EF_MIPS_ABI_EABI32:
1520 arch_flags |= lldb_private::ArchSpec::eMIPSABI_EABI32;
1521 break;
1522 case EF_MIPS_ABI_EABI64:
1523 arch_flags |= lldb_private::ArchSpec::eMIPSABI_EABI64;
1524 break;
1525 default:
1526 // ABI Mask doesn't cover N32 and N64 ABI.
1527 if (header.e_ident[EI_CLASS] == llvm::ELF::ELFCLASS64)
1528 arch_flags |= lldb_private::ArchSpec::eMIPSABI_N64;
1529 else if (header.e_flags & llvm::ELF::EF_MIPS_ABI2)
1530 arch_flags |= lldb_private::ArchSpec::eMIPSABI_N32;
1531 break;
1532 }
1533 arch_spec.SetFlags(arch_flags);
1534 }
1535
1536 if (arch_spec.GetMachine() == llvm::Triple::arm ||
1537 arch_spec.GetMachine() == llvm::Triple::thumb) {
1538 DataExtractor data;
1539
1540 if (sheader.sh_type == SHT_ARM_ATTRIBUTES && section_size != 0 &&
1541 data.SetData(object_data, sheader.sh_offset, section_size) == section_size)
1542 ParseARMAttributes(data, section_size, arch_spec);
1543 }
1544
1545 if (name == g_sect_name_gnu_debuglink) {
1546 DataExtractor data;
1547 if (section_size && (data.SetData(object_data, sheader.sh_offset,
1548 section_size) == section_size)) {
1549 lldb::offset_t gnu_debuglink_offset = 0;
1550 gnu_debuglink_file = data.GetCStr(&gnu_debuglink_offset);
1551 gnu_debuglink_offset = llvm::alignTo(gnu_debuglink_offset, 4);
1552 data.GetU32(&gnu_debuglink_offset, &gnu_debuglink_crc, 1);
1553 }
1554 }
1555
1556 // Process ELF note section entries.
1557 bool is_note_header = (sheader.sh_type == SHT_NOTE);
1558
1559 // The section header ".note.android.ident" is stored as a
1560 // PROGBITS type header but it is actually a note header.
1561 static ConstString g_sect_name_android_ident(".note.android.ident");
1562 if (!is_note_header && name == g_sect_name_android_ident)
1563 is_note_header = true;
1564
1565 if (is_note_header) {
1566 // Allow notes to refine module info.
1567 DataExtractor data;
1568 if (section_size && (data.SetData(object_data, sheader.sh_offset,
1569 section_size) == section_size)) {
1570 Status error = RefineModuleDetailsFromNote(data, arch_spec, uuid);
1571 if (error.Fail()) {
1572 LLDB_LOGF(log, "ObjectFileELF::%s ELF note processing failed: %s",
1573 __FUNCTION__, error.AsCString());
1574 }
1575 }
1576 }
1577 }
1578
1579 // Make any unknown triple components to be unspecified unknowns.
1580 if (arch_spec.GetTriple().getVendor() == llvm::Triple::UnknownVendor)
1581 arch_spec.GetTriple().setVendorName(llvm::StringRef());
1582 if (arch_spec.GetTriple().getOS() == llvm::Triple::UnknownOS)
1583 arch_spec.GetTriple().setOSName(llvm::StringRef());
1584
1585 return section_headers.size();
1586 }
1587 }
1588
1589 section_headers.clear();
1590 return 0;
1591 }
1592
1593 llvm::StringRef
StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const1594 ObjectFileELF::StripLinkerSymbolAnnotations(llvm::StringRef symbol_name) const {
1595 size_t pos = symbol_name.find('@');
1596 return symbol_name.substr(0, pos);
1597 }
1598
1599 // ParseSectionHeaders
ParseSectionHeaders()1600 size_t ObjectFileELF::ParseSectionHeaders() {
1601 return GetSectionHeaderInfo(m_section_headers, m_data, m_header, m_uuid,
1602 m_gnu_debuglink_file, m_gnu_debuglink_crc,
1603 m_arch_spec);
1604 }
1605
1606 const ObjectFileELF::ELFSectionHeaderInfo *
GetSectionHeaderByIndex(lldb::user_id_t id)1607 ObjectFileELF::GetSectionHeaderByIndex(lldb::user_id_t id) {
1608 if (!ParseSectionHeaders())
1609 return nullptr;
1610
1611 if (id < m_section_headers.size())
1612 return &m_section_headers[id];
1613
1614 return nullptr;
1615 }
1616
GetSectionIndexByName(const char * name)1617 lldb::user_id_t ObjectFileELF::GetSectionIndexByName(const char *name) {
1618 if (!name || !name[0] || !ParseSectionHeaders())
1619 return 0;
1620 for (size_t i = 1; i < m_section_headers.size(); ++i)
1621 if (m_section_headers[i].section_name == ConstString(name))
1622 return i;
1623 return 0;
1624 }
1625
GetSectionTypeFromName(llvm::StringRef Name)1626 static SectionType GetSectionTypeFromName(llvm::StringRef Name) {
1627 if (Name.consume_front(".debug_")) {
1628 return llvm::StringSwitch<SectionType>(Name)
1629 .Case("abbrev", eSectionTypeDWARFDebugAbbrev)
1630 .Case("abbrev.dwo", eSectionTypeDWARFDebugAbbrevDwo)
1631 .Case("addr", eSectionTypeDWARFDebugAddr)
1632 .Case("aranges", eSectionTypeDWARFDebugAranges)
1633 .Case("cu_index", eSectionTypeDWARFDebugCuIndex)
1634 .Case("frame", eSectionTypeDWARFDebugFrame)
1635 .Case("info", eSectionTypeDWARFDebugInfo)
1636 .Case("info.dwo", eSectionTypeDWARFDebugInfoDwo)
1637 .Cases("line", "line.dwo", eSectionTypeDWARFDebugLine)
1638 .Cases("line_str", "line_str.dwo", eSectionTypeDWARFDebugLineStr)
1639 .Case("loc", eSectionTypeDWARFDebugLoc)
1640 .Case("loc.dwo", eSectionTypeDWARFDebugLocDwo)
1641 .Case("loclists", eSectionTypeDWARFDebugLocLists)
1642 .Case("loclists.dwo", eSectionTypeDWARFDebugLocListsDwo)
1643 .Case("macinfo", eSectionTypeDWARFDebugMacInfo)
1644 .Cases("macro", "macro.dwo", eSectionTypeDWARFDebugMacro)
1645 .Case("names", eSectionTypeDWARFDebugNames)
1646 .Case("pubnames", eSectionTypeDWARFDebugPubNames)
1647 .Case("pubtypes", eSectionTypeDWARFDebugPubTypes)
1648 .Case("ranges", eSectionTypeDWARFDebugRanges)
1649 .Case("rnglists", eSectionTypeDWARFDebugRngLists)
1650 .Case("rnglists.dwo", eSectionTypeDWARFDebugRngListsDwo)
1651 .Case("str", eSectionTypeDWARFDebugStr)
1652 .Case("str.dwo", eSectionTypeDWARFDebugStrDwo)
1653 .Case("str_offsets", eSectionTypeDWARFDebugStrOffsets)
1654 .Case("str_offsets.dwo", eSectionTypeDWARFDebugStrOffsetsDwo)
1655 .Case("tu_index", eSectionTypeDWARFDebugTuIndex)
1656 .Case("types", eSectionTypeDWARFDebugTypes)
1657 .Case("types.dwo", eSectionTypeDWARFDebugTypesDwo)
1658 .Default(eSectionTypeOther);
1659 }
1660 return llvm::StringSwitch<SectionType>(Name)
1661 .Case(".ARM.exidx", eSectionTypeARMexidx)
1662 .Case(".ARM.extab", eSectionTypeARMextab)
1663 .Cases(".bss", ".tbss", eSectionTypeZeroFill)
1664 .Cases(".data", ".tdata", eSectionTypeData)
1665 .Case(".eh_frame", eSectionTypeEHFrame)
1666 .Case(".gnu_debugaltlink", eSectionTypeDWARFGNUDebugAltLink)
1667 .Case(".gosymtab", eSectionTypeGoSymtab)
1668 .Case(".text", eSectionTypeCode)
1669 .Default(eSectionTypeOther);
1670 }
1671
GetSectionType(const ELFSectionHeaderInfo & H) const1672 SectionType ObjectFileELF::GetSectionType(const ELFSectionHeaderInfo &H) const {
1673 switch (H.sh_type) {
1674 case SHT_PROGBITS:
1675 if (H.sh_flags & SHF_EXECINSTR)
1676 return eSectionTypeCode;
1677 break;
1678 case SHT_SYMTAB:
1679 return eSectionTypeELFSymbolTable;
1680 case SHT_DYNSYM:
1681 return eSectionTypeELFDynamicSymbols;
1682 case SHT_RELA:
1683 case SHT_REL:
1684 return eSectionTypeELFRelocationEntries;
1685 case SHT_DYNAMIC:
1686 return eSectionTypeELFDynamicLinkInfo;
1687 }
1688 return GetSectionTypeFromName(H.section_name.GetStringRef());
1689 }
1690
GetTargetByteSize(SectionType Type,const ArchSpec & arch)1691 static uint32_t GetTargetByteSize(SectionType Type, const ArchSpec &arch) {
1692 switch (Type) {
1693 case eSectionTypeData:
1694 case eSectionTypeZeroFill:
1695 return arch.GetDataByteSize();
1696 case eSectionTypeCode:
1697 return arch.GetCodeByteSize();
1698 default:
1699 return 1;
1700 }
1701 }
1702
GetPermissions(const ELFSectionHeader & H)1703 static Permissions GetPermissions(const ELFSectionHeader &H) {
1704 Permissions Perm = Permissions(0);
1705 if (H.sh_flags & SHF_ALLOC)
1706 Perm |= ePermissionsReadable;
1707 if (H.sh_flags & SHF_WRITE)
1708 Perm |= ePermissionsWritable;
1709 if (H.sh_flags & SHF_EXECINSTR)
1710 Perm |= ePermissionsExecutable;
1711 return Perm;
1712 }
1713
GetPermissions(const ELFProgramHeader & H)1714 static Permissions GetPermissions(const ELFProgramHeader &H) {
1715 Permissions Perm = Permissions(0);
1716 if (H.p_flags & PF_R)
1717 Perm |= ePermissionsReadable;
1718 if (H.p_flags & PF_W)
1719 Perm |= ePermissionsWritable;
1720 if (H.p_flags & PF_X)
1721 Perm |= ePermissionsExecutable;
1722 return Perm;
1723 }
1724
1725 namespace {
1726
1727 using VMRange = lldb_private::Range<addr_t, addr_t>;
1728
1729 struct SectionAddressInfo {
1730 SectionSP Segment;
1731 VMRange Range;
1732 };
1733
1734 // (Unlinked) ELF object files usually have 0 for every section address, meaning
1735 // we need to compute synthetic addresses in order for "file addresses" from
1736 // different sections to not overlap. This class handles that logic.
1737 class VMAddressProvider {
1738 using VMMap = llvm::IntervalMap<addr_t, SectionSP, 4,
1739 llvm::IntervalMapHalfOpenInfo<addr_t>>;
1740
1741 ObjectFile::Type ObjectType;
1742 addr_t NextVMAddress = 0;
1743 VMMap::Allocator Alloc;
1744 VMMap Segments{Alloc};
1745 VMMap Sections{Alloc};
1746 lldb_private::Log *Log = GetLog(LLDBLog::Modules);
1747 size_t SegmentCount = 0;
1748 std::string SegmentName;
1749
GetVMRange(const ELFSectionHeader & H)1750 VMRange GetVMRange(const ELFSectionHeader &H) {
1751 addr_t Address = H.sh_addr;
1752 addr_t Size = H.sh_flags & SHF_ALLOC ? H.sh_size : 0;
1753 if (ObjectType == ObjectFile::Type::eTypeObjectFile && Segments.empty() && (H.sh_flags & SHF_ALLOC)) {
1754 NextVMAddress =
1755 llvm::alignTo(NextVMAddress, std::max<addr_t>(H.sh_addralign, 1));
1756 Address = NextVMAddress;
1757 NextVMAddress += Size;
1758 }
1759 return VMRange(Address, Size);
1760 }
1761
1762 public:
VMAddressProvider(ObjectFile::Type Type,llvm::StringRef SegmentName)1763 VMAddressProvider(ObjectFile::Type Type, llvm::StringRef SegmentName)
1764 : ObjectType(Type), SegmentName(std::string(SegmentName)) {}
1765
GetNextSegmentName() const1766 std::string GetNextSegmentName() const {
1767 return llvm::formatv("{0}[{1}]", SegmentName, SegmentCount).str();
1768 }
1769
GetAddressInfo(const ELFProgramHeader & H)1770 std::optional<VMRange> GetAddressInfo(const ELFProgramHeader &H) {
1771 if (H.p_memsz == 0) {
1772 LLDB_LOG(Log, "Ignoring zero-sized {0} segment. Corrupt object file?",
1773 SegmentName);
1774 return std::nullopt;
1775 }
1776
1777 if (Segments.overlaps(H.p_vaddr, H.p_vaddr + H.p_memsz)) {
1778 LLDB_LOG(Log, "Ignoring overlapping {0} segment. Corrupt object file?",
1779 SegmentName);
1780 return std::nullopt;
1781 }
1782 return VMRange(H.p_vaddr, H.p_memsz);
1783 }
1784
GetAddressInfo(const ELFSectionHeader & H)1785 std::optional<SectionAddressInfo> GetAddressInfo(const ELFSectionHeader &H) {
1786 VMRange Range = GetVMRange(H);
1787 SectionSP Segment;
1788 auto It = Segments.find(Range.GetRangeBase());
1789 if ((H.sh_flags & SHF_ALLOC) && It.valid()) {
1790 addr_t MaxSize;
1791 if (It.start() <= Range.GetRangeBase()) {
1792 MaxSize = It.stop() - Range.GetRangeBase();
1793 Segment = *It;
1794 } else
1795 MaxSize = It.start() - Range.GetRangeBase();
1796 if (Range.GetByteSize() > MaxSize) {
1797 LLDB_LOG(Log, "Shortening section crossing segment boundaries. "
1798 "Corrupt object file?");
1799 Range.SetByteSize(MaxSize);
1800 }
1801 }
1802 if (Range.GetByteSize() > 0 &&
1803 Sections.overlaps(Range.GetRangeBase(), Range.GetRangeEnd())) {
1804 LLDB_LOG(Log, "Ignoring overlapping section. Corrupt object file?");
1805 return std::nullopt;
1806 }
1807 if (Segment)
1808 Range.Slide(-Segment->GetFileAddress());
1809 return SectionAddressInfo{Segment, Range};
1810 }
1811
AddSegment(const VMRange & Range,SectionSP Seg)1812 void AddSegment(const VMRange &Range, SectionSP Seg) {
1813 Segments.insert(Range.GetRangeBase(), Range.GetRangeEnd(), std::move(Seg));
1814 ++SegmentCount;
1815 }
1816
AddSection(SectionAddressInfo Info,SectionSP Sect)1817 void AddSection(SectionAddressInfo Info, SectionSP Sect) {
1818 if (Info.Range.GetByteSize() == 0)
1819 return;
1820 if (Info.Segment)
1821 Info.Range.Slide(Info.Segment->GetFileAddress());
1822 Sections.insert(Info.Range.GetRangeBase(), Info.Range.GetRangeEnd(),
1823 std::move(Sect));
1824 }
1825 };
1826 }
1827
CreateSections(SectionList & unified_section_list)1828 void ObjectFileELF::CreateSections(SectionList &unified_section_list) {
1829 if (m_sections_up)
1830 return;
1831
1832 m_sections_up = std::make_unique<SectionList>();
1833 VMAddressProvider regular_provider(GetType(), "PT_LOAD");
1834 VMAddressProvider tls_provider(GetType(), "PT_TLS");
1835
1836 for (const auto &EnumPHdr : llvm::enumerate(ProgramHeaders())) {
1837 const ELFProgramHeader &PHdr = EnumPHdr.value();
1838 if (PHdr.p_type != PT_LOAD && PHdr.p_type != PT_TLS)
1839 continue;
1840
1841 VMAddressProvider &provider =
1842 PHdr.p_type == PT_TLS ? tls_provider : regular_provider;
1843 auto InfoOr = provider.GetAddressInfo(PHdr);
1844 if (!InfoOr)
1845 continue;
1846
1847 uint32_t Log2Align = llvm::Log2_64(std::max<elf_xword>(PHdr.p_align, 1));
1848 SectionSP Segment = std::make_shared<Section>(
1849 GetModule(), this, SegmentID(EnumPHdr.index()),
1850 ConstString(provider.GetNextSegmentName()), eSectionTypeContainer,
1851 InfoOr->GetRangeBase(), InfoOr->GetByteSize(), PHdr.p_offset,
1852 PHdr.p_filesz, Log2Align, /*flags*/ 0);
1853 Segment->SetPermissions(GetPermissions(PHdr));
1854 Segment->SetIsThreadSpecific(PHdr.p_type == PT_TLS);
1855 m_sections_up->AddSection(Segment);
1856
1857 provider.AddSegment(*InfoOr, std::move(Segment));
1858 }
1859
1860 ParseSectionHeaders();
1861 if (m_section_headers.empty())
1862 return;
1863
1864 for (SectionHeaderCollIter I = std::next(m_section_headers.begin());
1865 I != m_section_headers.end(); ++I) {
1866 const ELFSectionHeaderInfo &header = *I;
1867
1868 ConstString &name = I->section_name;
1869 const uint64_t file_size =
1870 header.sh_type == SHT_NOBITS ? 0 : header.sh_size;
1871
1872 VMAddressProvider &provider =
1873 header.sh_flags & SHF_TLS ? tls_provider : regular_provider;
1874 auto InfoOr = provider.GetAddressInfo(header);
1875 if (!InfoOr)
1876 continue;
1877
1878 SectionType sect_type = GetSectionType(header);
1879
1880 const uint32_t target_bytes_size =
1881 GetTargetByteSize(sect_type, m_arch_spec);
1882
1883 elf::elf_xword log2align =
1884 (header.sh_addralign == 0) ? 0 : llvm::Log2_64(header.sh_addralign);
1885
1886 SectionSP section_sp(new Section(
1887 InfoOr->Segment, GetModule(), // Module to which this section belongs.
1888 this, // ObjectFile to which this section belongs and should
1889 // read section data from.
1890 SectionIndex(I), // Section ID.
1891 name, // Section name.
1892 sect_type, // Section type.
1893 InfoOr->Range.GetRangeBase(), // VM address.
1894 InfoOr->Range.GetByteSize(), // VM size in bytes of this section.
1895 header.sh_offset, // Offset of this section in the file.
1896 file_size, // Size of the section as found in the file.
1897 log2align, // Alignment of the section
1898 header.sh_flags, // Flags for this section.
1899 target_bytes_size)); // Number of host bytes per target byte
1900
1901 section_sp->SetPermissions(GetPermissions(header));
1902 section_sp->SetIsThreadSpecific(header.sh_flags & SHF_TLS);
1903 (InfoOr->Segment ? InfoOr->Segment->GetChildren() : *m_sections_up)
1904 .AddSection(section_sp);
1905 provider.AddSection(std::move(*InfoOr), std::move(section_sp));
1906 }
1907
1908 // For eTypeDebugInfo files, the Symbol Vendor will take care of updating the
1909 // unified section list.
1910 if (GetType() != eTypeDebugInfo)
1911 unified_section_list = *m_sections_up;
1912
1913 // If there's a .gnu_debugdata section, we'll try to read the .symtab that's
1914 // embedded in there and replace the one in the original object file (if any).
1915 // If there's none in the orignal object file, we add it to it.
1916 if (auto gdd_obj_file = GetGnuDebugDataObjectFile()) {
1917 if (auto gdd_objfile_section_list = gdd_obj_file->GetSectionList()) {
1918 if (SectionSP symtab_section_sp =
1919 gdd_objfile_section_list->FindSectionByType(
1920 eSectionTypeELFSymbolTable, true)) {
1921 SectionSP module_section_sp = unified_section_list.FindSectionByType(
1922 eSectionTypeELFSymbolTable, true);
1923 if (module_section_sp)
1924 unified_section_list.ReplaceSection(module_section_sp->GetID(),
1925 symtab_section_sp);
1926 else
1927 unified_section_list.AddSection(symtab_section_sp);
1928 }
1929 }
1930 }
1931 }
1932
GetGnuDebugDataObjectFile()1933 std::shared_ptr<ObjectFileELF> ObjectFileELF::GetGnuDebugDataObjectFile() {
1934 if (m_gnu_debug_data_object_file != nullptr)
1935 return m_gnu_debug_data_object_file;
1936
1937 SectionSP section =
1938 GetSectionList()->FindSectionByName(ConstString(".gnu_debugdata"));
1939 if (!section)
1940 return nullptr;
1941
1942 if (!lldb_private::lzma::isAvailable()) {
1943 GetModule()->ReportWarning(
1944 "No LZMA support found for reading .gnu_debugdata section");
1945 return nullptr;
1946 }
1947
1948 // Uncompress the data
1949 DataExtractor data;
1950 section->GetSectionData(data);
1951 llvm::SmallVector<uint8_t, 0> uncompressedData;
1952 auto err = lldb_private::lzma::uncompress(data.GetData(), uncompressedData);
1953 if (err) {
1954 GetModule()->ReportWarning(
1955 "An error occurred while decompression the section {0}: {1}",
1956 section->GetName().AsCString(), llvm::toString(std::move(err)).c_str());
1957 return nullptr;
1958 }
1959
1960 // Construct ObjectFileELF object from decompressed buffer
1961 DataBufferSP gdd_data_buf(
1962 new DataBufferHeap(uncompressedData.data(), uncompressedData.size()));
1963 auto fspec = GetFileSpec().CopyByAppendingPathComponent(
1964 llvm::StringRef("gnu_debugdata"));
1965 m_gnu_debug_data_object_file.reset(new ObjectFileELF(
1966 GetModule(), gdd_data_buf, 0, &fspec, 0, gdd_data_buf->GetByteSize()));
1967
1968 // This line is essential; otherwise a breakpoint can be set but not hit.
1969 m_gnu_debug_data_object_file->SetType(ObjectFile::eTypeDebugInfo);
1970
1971 ArchSpec spec = m_gnu_debug_data_object_file->GetArchitecture();
1972 if (spec && m_gnu_debug_data_object_file->SetModulesArchitecture(spec))
1973 return m_gnu_debug_data_object_file;
1974
1975 return nullptr;
1976 }
1977
1978 // Find the arm/aarch64 mapping symbol character in the given symbol name.
1979 // Mapping symbols have the form of "$<char>[.<any>]*". Additionally we
1980 // recognize cases when the mapping symbol prefixed by an arbitrary string
1981 // because if a symbol prefix added to each symbol in the object file with
1982 // objcopy then the mapping symbols are also prefixed.
FindArmAarch64MappingSymbol(const char * symbol_name)1983 static char FindArmAarch64MappingSymbol(const char *symbol_name) {
1984 if (!symbol_name)
1985 return '\0';
1986
1987 const char *dollar_pos = ::strchr(symbol_name, '$');
1988 if (!dollar_pos || dollar_pos[1] == '\0')
1989 return '\0';
1990
1991 if (dollar_pos[2] == '\0' || dollar_pos[2] == '.')
1992 return dollar_pos[1];
1993 return '\0';
1994 }
1995
1996 #define STO_MIPS_ISA (3 << 6)
1997 #define STO_MICROMIPS (2 << 6)
1998 #define IS_MICROMIPS(ST_OTHER) (((ST_OTHER)&STO_MIPS_ISA) == STO_MICROMIPS)
1999
2000 // private
ParseSymbols(Symtab * symtab,user_id_t start_id,SectionList * section_list,const size_t num_symbols,const DataExtractor & symtab_data,const DataExtractor & strtab_data)2001 unsigned ObjectFileELF::ParseSymbols(Symtab *symtab, user_id_t start_id,
2002 SectionList *section_list,
2003 const size_t num_symbols,
2004 const DataExtractor &symtab_data,
2005 const DataExtractor &strtab_data) {
2006 ELFSymbol symbol;
2007 lldb::offset_t offset = 0;
2008
2009 static ConstString text_section_name(".text");
2010 static ConstString init_section_name(".init");
2011 static ConstString fini_section_name(".fini");
2012 static ConstString ctors_section_name(".ctors");
2013 static ConstString dtors_section_name(".dtors");
2014
2015 static ConstString data_section_name(".data");
2016 static ConstString rodata_section_name(".rodata");
2017 static ConstString rodata1_section_name(".rodata1");
2018 static ConstString data2_section_name(".data1");
2019 static ConstString bss_section_name(".bss");
2020 static ConstString opd_section_name(".opd"); // For ppc64
2021
2022 // On Android the oatdata and the oatexec symbols in the oat and odex files
2023 // covers the full .text section what causes issues with displaying unusable
2024 // symbol name to the user and very slow unwinding speed because the
2025 // instruction emulation based unwind plans try to emulate all instructions
2026 // in these symbols. Don't add these symbols to the symbol list as they have
2027 // no use for the debugger and they are causing a lot of trouble. Filtering
2028 // can't be restricted to Android because this special object file don't
2029 // contain the note section specifying the environment to Android but the
2030 // custom extension and file name makes it highly unlikely that this will
2031 // collide with anything else.
2032 ConstString file_extension = m_file.GetFileNameExtension();
2033 bool skip_oatdata_oatexec =
2034 file_extension == ".oat" || file_extension == ".odex";
2035
2036 ArchSpec arch = GetArchitecture();
2037 ModuleSP module_sp(GetModule());
2038 SectionList *module_section_list =
2039 module_sp ? module_sp->GetSectionList() : nullptr;
2040
2041 // Local cache to avoid doing a FindSectionByName for each symbol. The "const
2042 // char*" key must came from a ConstString object so they can be compared by
2043 // pointer
2044 std::unordered_map<const char *, lldb::SectionSP> section_name_to_section;
2045
2046 unsigned i;
2047 for (i = 0; i < num_symbols; ++i) {
2048 if (!symbol.Parse(symtab_data, &offset))
2049 break;
2050
2051 const char *symbol_name = strtab_data.PeekCStr(symbol.st_name);
2052 if (!symbol_name)
2053 symbol_name = "";
2054
2055 // No need to add non-section symbols that have no names
2056 if (symbol.getType() != STT_SECTION &&
2057 (symbol_name == nullptr || symbol_name[0] == '\0'))
2058 continue;
2059
2060 // Skipping oatdata and oatexec sections if it is requested. See details
2061 // above the definition of skip_oatdata_oatexec for the reasons.
2062 if (skip_oatdata_oatexec && (::strcmp(symbol_name, "oatdata") == 0 ||
2063 ::strcmp(symbol_name, "oatexec") == 0))
2064 continue;
2065
2066 SectionSP symbol_section_sp;
2067 SymbolType symbol_type = eSymbolTypeInvalid;
2068 Elf64_Half shndx = symbol.st_shndx;
2069
2070 switch (shndx) {
2071 case SHN_ABS:
2072 symbol_type = eSymbolTypeAbsolute;
2073 break;
2074 case SHN_UNDEF:
2075 symbol_type = eSymbolTypeUndefined;
2076 break;
2077 default:
2078 symbol_section_sp = section_list->FindSectionByID(shndx);
2079 break;
2080 }
2081
2082 // If a symbol is undefined do not process it further even if it has a STT
2083 // type
2084 if (symbol_type != eSymbolTypeUndefined) {
2085 switch (symbol.getType()) {
2086 default:
2087 case STT_NOTYPE:
2088 // The symbol's type is not specified.
2089 break;
2090
2091 case STT_OBJECT:
2092 // The symbol is associated with a data object, such as a variable, an
2093 // array, etc.
2094 symbol_type = eSymbolTypeData;
2095 break;
2096
2097 case STT_FUNC:
2098 // The symbol is associated with a function or other executable code.
2099 symbol_type = eSymbolTypeCode;
2100 break;
2101
2102 case STT_SECTION:
2103 // The symbol is associated with a section. Symbol table entries of
2104 // this type exist primarily for relocation and normally have STB_LOCAL
2105 // binding.
2106 break;
2107
2108 case STT_FILE:
2109 // Conventionally, the symbol's name gives the name of the source file
2110 // associated with the object file. A file symbol has STB_LOCAL
2111 // binding, its section index is SHN_ABS, and it precedes the other
2112 // STB_LOCAL symbols for the file, if it is present.
2113 symbol_type = eSymbolTypeSourceFile;
2114 break;
2115
2116 case STT_GNU_IFUNC:
2117 // The symbol is associated with an indirect function. The actual
2118 // function will be resolved if it is referenced.
2119 symbol_type = eSymbolTypeResolver;
2120 break;
2121 }
2122 }
2123
2124 if (symbol_type == eSymbolTypeInvalid && symbol.getType() != STT_SECTION) {
2125 if (symbol_section_sp) {
2126 ConstString sect_name = symbol_section_sp->GetName();
2127 if (sect_name == text_section_name || sect_name == init_section_name ||
2128 sect_name == fini_section_name || sect_name == ctors_section_name ||
2129 sect_name == dtors_section_name) {
2130 symbol_type = eSymbolTypeCode;
2131 } else if (sect_name == data_section_name ||
2132 sect_name == data2_section_name ||
2133 sect_name == rodata_section_name ||
2134 sect_name == rodata1_section_name ||
2135 sect_name == bss_section_name) {
2136 symbol_type = eSymbolTypeData;
2137 }
2138 }
2139 }
2140
2141 int64_t symbol_value_offset = 0;
2142 uint32_t additional_flags = 0;
2143
2144 if (arch.IsValid()) {
2145 if (arch.GetMachine() == llvm::Triple::arm) {
2146 if (symbol.getBinding() == STB_LOCAL) {
2147 char mapping_symbol = FindArmAarch64MappingSymbol(symbol_name);
2148 if (symbol_type == eSymbolTypeCode) {
2149 switch (mapping_symbol) {
2150 case 'a':
2151 // $a[.<any>]* - marks an ARM instruction sequence
2152 m_address_class_map[symbol.st_value] = AddressClass::eCode;
2153 break;
2154 case 'b':
2155 case 't':
2156 // $b[.<any>]* - marks a THUMB BL instruction sequence
2157 // $t[.<any>]* - marks a THUMB instruction sequence
2158 m_address_class_map[symbol.st_value] =
2159 AddressClass::eCodeAlternateISA;
2160 break;
2161 case 'd':
2162 // $d[.<any>]* - marks a data item sequence (e.g. lit pool)
2163 m_address_class_map[symbol.st_value] = AddressClass::eData;
2164 break;
2165 }
2166 }
2167 if (mapping_symbol)
2168 continue;
2169 }
2170 } else if (arch.GetMachine() == llvm::Triple::aarch64) {
2171 if (symbol.getBinding() == STB_LOCAL) {
2172 char mapping_symbol = FindArmAarch64MappingSymbol(symbol_name);
2173 if (symbol_type == eSymbolTypeCode) {
2174 switch (mapping_symbol) {
2175 case 'x':
2176 // $x[.<any>]* - marks an A64 instruction sequence
2177 m_address_class_map[symbol.st_value] = AddressClass::eCode;
2178 break;
2179 case 'd':
2180 // $d[.<any>]* - marks a data item sequence (e.g. lit pool)
2181 m_address_class_map[symbol.st_value] = AddressClass::eData;
2182 break;
2183 }
2184 }
2185 if (mapping_symbol)
2186 continue;
2187 }
2188 }
2189
2190 if (arch.GetMachine() == llvm::Triple::arm) {
2191 if (symbol_type == eSymbolTypeCode) {
2192 if (symbol.st_value & 1) {
2193 // Subtracting 1 from the address effectively unsets the low order
2194 // bit, which results in the address actually pointing to the
2195 // beginning of the symbol. This delta will be used below in
2196 // conjunction with symbol.st_value to produce the final
2197 // symbol_value that we store in the symtab.
2198 symbol_value_offset = -1;
2199 m_address_class_map[symbol.st_value ^ 1] =
2200 AddressClass::eCodeAlternateISA;
2201 } else {
2202 // This address is ARM
2203 m_address_class_map[symbol.st_value] = AddressClass::eCode;
2204 }
2205 }
2206 }
2207
2208 /*
2209 * MIPS:
2210 * The bit #0 of an address is used for ISA mode (1 for microMIPS, 0 for
2211 * MIPS).
2212 * This allows processor to switch between microMIPS and MIPS without any
2213 * need
2214 * for special mode-control register. However, apart from .debug_line,
2215 * none of
2216 * the ELF/DWARF sections set the ISA bit (for symbol or section). Use
2217 * st_other
2218 * flag to check whether the symbol is microMIPS and then set the address
2219 * class
2220 * accordingly.
2221 */
2222 if (arch.IsMIPS()) {
2223 if (IS_MICROMIPS(symbol.st_other))
2224 m_address_class_map[symbol.st_value] = AddressClass::eCodeAlternateISA;
2225 else if ((symbol.st_value & 1) && (symbol_type == eSymbolTypeCode)) {
2226 symbol.st_value = symbol.st_value & (~1ull);
2227 m_address_class_map[symbol.st_value] = AddressClass::eCodeAlternateISA;
2228 } else {
2229 if (symbol_type == eSymbolTypeCode)
2230 m_address_class_map[symbol.st_value] = AddressClass::eCode;
2231 else if (symbol_type == eSymbolTypeData)
2232 m_address_class_map[symbol.st_value] = AddressClass::eData;
2233 else
2234 m_address_class_map[symbol.st_value] = AddressClass::eUnknown;
2235 }
2236 }
2237 }
2238
2239 // symbol_value_offset may contain 0 for ARM symbols or -1 for THUMB
2240 // symbols. See above for more details.
2241 uint64_t symbol_value = symbol.st_value + symbol_value_offset;
2242
2243 if (symbol_section_sp &&
2244 CalculateType() != ObjectFile::Type::eTypeObjectFile)
2245 symbol_value -= symbol_section_sp->GetFileAddress();
2246
2247 if (symbol_section_sp && module_section_list &&
2248 module_section_list != section_list) {
2249 ConstString sect_name = symbol_section_sp->GetName();
2250 auto section_it = section_name_to_section.find(sect_name.GetCString());
2251 if (section_it == section_name_to_section.end())
2252 section_it =
2253 section_name_to_section
2254 .emplace(sect_name.GetCString(),
2255 module_section_list->FindSectionByName(sect_name))
2256 .first;
2257 if (section_it->second)
2258 symbol_section_sp = section_it->second;
2259 }
2260
2261 bool is_global = symbol.getBinding() == STB_GLOBAL;
2262 uint32_t flags = symbol.st_other << 8 | symbol.st_info | additional_flags;
2263 llvm::StringRef symbol_ref(symbol_name);
2264
2265 // Symbol names may contain @VERSION suffixes. Find those and strip them
2266 // temporarily.
2267 size_t version_pos = symbol_ref.find('@');
2268 bool has_suffix = version_pos != llvm::StringRef::npos;
2269 llvm::StringRef symbol_bare = symbol_ref.substr(0, version_pos);
2270 Mangled mangled(symbol_bare);
2271
2272 // Now append the suffix back to mangled and unmangled names. Only do it if
2273 // the demangling was successful (string is not empty).
2274 if (has_suffix) {
2275 llvm::StringRef suffix = symbol_ref.substr(version_pos);
2276
2277 llvm::StringRef mangled_name = mangled.GetMangledName().GetStringRef();
2278 if (!mangled_name.empty())
2279 mangled.SetMangledName(ConstString((mangled_name + suffix).str()));
2280
2281 ConstString demangled = mangled.GetDemangledName();
2282 llvm::StringRef demangled_name = demangled.GetStringRef();
2283 if (!demangled_name.empty())
2284 mangled.SetDemangledName(ConstString((demangled_name + suffix).str()));
2285 }
2286
2287 // In ELF all symbol should have a valid size but it is not true for some
2288 // function symbols coming from hand written assembly. As none of the
2289 // function symbol should have 0 size we try to calculate the size for
2290 // these symbols in the symtab with saying that their original size is not
2291 // valid.
2292 bool symbol_size_valid =
2293 symbol.st_size != 0 || symbol.getType() != STT_FUNC;
2294
2295 Symbol dc_symbol(
2296 i + start_id, // ID is the original symbol table index.
2297 mangled,
2298 symbol_type, // Type of this symbol
2299 is_global, // Is this globally visible?
2300 false, // Is this symbol debug info?
2301 false, // Is this symbol a trampoline?
2302 false, // Is this symbol artificial?
2303 AddressRange(symbol_section_sp, // Section in which this symbol is
2304 // defined or null.
2305 symbol_value, // Offset in section or symbol value.
2306 symbol.st_size), // Size in bytes of this symbol.
2307 symbol_size_valid, // Symbol size is valid
2308 has_suffix, // Contains linker annotations?
2309 flags); // Symbol flags.
2310 if (symbol.getBinding() == STB_WEAK)
2311 dc_symbol.SetIsWeak(true);
2312 symtab->AddSymbol(dc_symbol);
2313 }
2314 return i;
2315 }
2316
ParseSymbolTable(Symtab * symbol_table,user_id_t start_id,lldb_private::Section * symtab)2317 unsigned ObjectFileELF::ParseSymbolTable(Symtab *symbol_table,
2318 user_id_t start_id,
2319 lldb_private::Section *symtab) {
2320 if (symtab->GetObjectFile() != this) {
2321 // If the symbol table section is owned by a different object file, have it
2322 // do the parsing.
2323 ObjectFileELF *obj_file_elf =
2324 static_cast<ObjectFileELF *>(symtab->GetObjectFile());
2325 return obj_file_elf->ParseSymbolTable(symbol_table, start_id, symtab);
2326 }
2327
2328 // Get section list for this object file.
2329 SectionList *section_list = m_sections_up.get();
2330 if (!section_list)
2331 return 0;
2332
2333 user_id_t symtab_id = symtab->GetID();
2334 const ELFSectionHeaderInfo *symtab_hdr = GetSectionHeaderByIndex(symtab_id);
2335 assert(symtab_hdr->sh_type == SHT_SYMTAB ||
2336 symtab_hdr->sh_type == SHT_DYNSYM);
2337
2338 // sh_link: section header index of associated string table.
2339 user_id_t strtab_id = symtab_hdr->sh_link;
2340 Section *strtab = section_list->FindSectionByID(strtab_id).get();
2341
2342 if (symtab && strtab) {
2343 assert(symtab->GetObjectFile() == this);
2344 assert(strtab->GetObjectFile() == this);
2345
2346 DataExtractor symtab_data;
2347 DataExtractor strtab_data;
2348 if (ReadSectionData(symtab, symtab_data) &&
2349 ReadSectionData(strtab, strtab_data)) {
2350 size_t num_symbols = symtab_data.GetByteSize() / symtab_hdr->sh_entsize;
2351
2352 return ParseSymbols(symbol_table, start_id, section_list, num_symbols,
2353 symtab_data, strtab_data);
2354 }
2355 }
2356
2357 return 0;
2358 }
2359
ParseDynamicSymbols()2360 size_t ObjectFileELF::ParseDynamicSymbols() {
2361 if (m_dynamic_symbols.size())
2362 return m_dynamic_symbols.size();
2363
2364 SectionList *section_list = GetSectionList();
2365 if (!section_list)
2366 return 0;
2367
2368 // Find the SHT_DYNAMIC section.
2369 Section *dynsym =
2370 section_list->FindSectionByType(eSectionTypeELFDynamicLinkInfo, true)
2371 .get();
2372 if (!dynsym)
2373 return 0;
2374 assert(dynsym->GetObjectFile() == this);
2375
2376 ELFDynamic symbol;
2377 DataExtractor dynsym_data;
2378 if (ReadSectionData(dynsym, dynsym_data)) {
2379 const lldb::offset_t section_size = dynsym_data.GetByteSize();
2380 lldb::offset_t cursor = 0;
2381
2382 while (cursor < section_size) {
2383 if (!symbol.Parse(dynsym_data, &cursor))
2384 break;
2385
2386 m_dynamic_symbols.push_back(symbol);
2387 }
2388 }
2389
2390 return m_dynamic_symbols.size();
2391 }
2392
FindDynamicSymbol(unsigned tag)2393 const ELFDynamic *ObjectFileELF::FindDynamicSymbol(unsigned tag) {
2394 if (!ParseDynamicSymbols())
2395 return nullptr;
2396
2397 DynamicSymbolCollIter I = m_dynamic_symbols.begin();
2398 DynamicSymbolCollIter E = m_dynamic_symbols.end();
2399 for (; I != E; ++I) {
2400 ELFDynamic *symbol = &*I;
2401
2402 if (symbol->d_tag == tag)
2403 return symbol;
2404 }
2405
2406 return nullptr;
2407 }
2408
PLTRelocationType()2409 unsigned ObjectFileELF::PLTRelocationType() {
2410 // DT_PLTREL
2411 // This member specifies the type of relocation entry to which the
2412 // procedure linkage table refers. The d_val member holds DT_REL or
2413 // DT_RELA, as appropriate. All relocations in a procedure linkage table
2414 // must use the same relocation.
2415 const ELFDynamic *symbol = FindDynamicSymbol(DT_PLTREL);
2416
2417 if (symbol)
2418 return symbol->d_val;
2419
2420 return 0;
2421 }
2422
2423 // Returns the size of the normal plt entries and the offset of the first
2424 // normal plt entry. The 0th entry in the plt table is usually a resolution
2425 // entry which have different size in some architectures then the rest of the
2426 // plt entries.
2427 static std::pair<uint64_t, uint64_t>
GetPltEntrySizeAndOffset(const ELFSectionHeader * rel_hdr,const ELFSectionHeader * plt_hdr)2428 GetPltEntrySizeAndOffset(const ELFSectionHeader *rel_hdr,
2429 const ELFSectionHeader *plt_hdr) {
2430 const elf_xword num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2431
2432 // Clang 3.3 sets entsize to 4 for 32-bit binaries, but the plt entries are
2433 // 16 bytes. So round the entsize up by the alignment if addralign is set.
2434 elf_xword plt_entsize =
2435 plt_hdr->sh_addralign
2436 ? llvm::alignTo(plt_hdr->sh_entsize, plt_hdr->sh_addralign)
2437 : plt_hdr->sh_entsize;
2438
2439 // Some linkers e.g ld for arm, fill plt_hdr->sh_entsize field incorrectly.
2440 // PLT entries relocation code in general requires multiple instruction and
2441 // should be greater than 4 bytes in most cases. Try to guess correct size
2442 // just in case.
2443 if (plt_entsize <= 4) {
2444 // The linker haven't set the plt_hdr->sh_entsize field. Try to guess the
2445 // size of the plt entries based on the number of entries and the size of
2446 // the plt section with the assumption that the size of the 0th entry is at
2447 // least as big as the size of the normal entries and it isn't much bigger
2448 // then that.
2449 if (plt_hdr->sh_addralign)
2450 plt_entsize = plt_hdr->sh_size / plt_hdr->sh_addralign /
2451 (num_relocations + 1) * plt_hdr->sh_addralign;
2452 else
2453 plt_entsize = plt_hdr->sh_size / (num_relocations + 1);
2454 }
2455
2456 elf_xword plt_offset = plt_hdr->sh_size - num_relocations * plt_entsize;
2457
2458 return std::make_pair(plt_entsize, plt_offset);
2459 }
2460
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)2461 static unsigned ParsePLTRelocations(
2462 Symtab *symbol_table, user_id_t start_id, unsigned rel_type,
2463 const ELFHeader *hdr, const ELFSectionHeader *rel_hdr,
2464 const ELFSectionHeader *plt_hdr, const ELFSectionHeader *sym_hdr,
2465 const lldb::SectionSP &plt_section_sp, DataExtractor &rel_data,
2466 DataExtractor &symtab_data, DataExtractor &strtab_data) {
2467 ELFRelocation rel(rel_type);
2468 ELFSymbol symbol;
2469 lldb::offset_t offset = 0;
2470
2471 uint64_t plt_offset, plt_entsize;
2472 std::tie(plt_entsize, plt_offset) =
2473 GetPltEntrySizeAndOffset(rel_hdr, plt_hdr);
2474 const elf_xword num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2475
2476 typedef unsigned (*reloc_info_fn)(const ELFRelocation &rel);
2477 reloc_info_fn reloc_type;
2478 reloc_info_fn reloc_symbol;
2479
2480 if (hdr->Is32Bit()) {
2481 reloc_type = ELFRelocation::RelocType32;
2482 reloc_symbol = ELFRelocation::RelocSymbol32;
2483 } else {
2484 reloc_type = ELFRelocation::RelocType64;
2485 reloc_symbol = ELFRelocation::RelocSymbol64;
2486 }
2487
2488 unsigned slot_type = hdr->GetRelocationJumpSlotType();
2489 unsigned i;
2490 for (i = 0; i < num_relocations; ++i) {
2491 if (!rel.Parse(rel_data, &offset))
2492 break;
2493
2494 if (reloc_type(rel) != slot_type)
2495 continue;
2496
2497 lldb::offset_t symbol_offset = reloc_symbol(rel) * sym_hdr->sh_entsize;
2498 if (!symbol.Parse(symtab_data, &symbol_offset))
2499 break;
2500
2501 const char *symbol_name = strtab_data.PeekCStr(symbol.st_name);
2502 uint64_t plt_index = plt_offset + i * plt_entsize;
2503
2504 Symbol jump_symbol(
2505 i + start_id, // Symbol table index
2506 symbol_name, // symbol name.
2507 eSymbolTypeTrampoline, // Type of this symbol
2508 false, // Is this globally visible?
2509 false, // Is this symbol debug info?
2510 true, // Is this symbol a trampoline?
2511 true, // Is this symbol artificial?
2512 plt_section_sp, // Section in which this symbol is defined or null.
2513 plt_index, // Offset in section or symbol value.
2514 plt_entsize, // Size in bytes of this symbol.
2515 true, // Size is valid
2516 false, // Contains linker annotations?
2517 0); // Symbol flags.
2518
2519 symbol_table->AddSymbol(jump_symbol);
2520 }
2521
2522 return i;
2523 }
2524
2525 unsigned
ParseTrampolineSymbols(Symtab * symbol_table,user_id_t start_id,const ELFSectionHeaderInfo * rel_hdr,user_id_t rel_id)2526 ObjectFileELF::ParseTrampolineSymbols(Symtab *symbol_table, user_id_t start_id,
2527 const ELFSectionHeaderInfo *rel_hdr,
2528 user_id_t rel_id) {
2529 assert(rel_hdr->sh_type == SHT_RELA || rel_hdr->sh_type == SHT_REL);
2530
2531 // The link field points to the associated symbol table.
2532 user_id_t symtab_id = rel_hdr->sh_link;
2533
2534 // If the link field doesn't point to the appropriate symbol name table then
2535 // try to find it by name as some compiler don't fill in the link fields.
2536 if (!symtab_id)
2537 symtab_id = GetSectionIndexByName(".dynsym");
2538
2539 // Get PLT section. We cannot use rel_hdr->sh_info, since current linkers
2540 // point that to the .got.plt or .got section instead of .plt.
2541 user_id_t plt_id = GetSectionIndexByName(".plt");
2542
2543 if (!symtab_id || !plt_id)
2544 return 0;
2545
2546 const ELFSectionHeaderInfo *plt_hdr = GetSectionHeaderByIndex(plt_id);
2547 if (!plt_hdr)
2548 return 0;
2549
2550 const ELFSectionHeaderInfo *sym_hdr = GetSectionHeaderByIndex(symtab_id);
2551 if (!sym_hdr)
2552 return 0;
2553
2554 SectionList *section_list = m_sections_up.get();
2555 if (!section_list)
2556 return 0;
2557
2558 Section *rel_section = section_list->FindSectionByID(rel_id).get();
2559 if (!rel_section)
2560 return 0;
2561
2562 SectionSP plt_section_sp(section_list->FindSectionByID(plt_id));
2563 if (!plt_section_sp)
2564 return 0;
2565
2566 Section *symtab = section_list->FindSectionByID(symtab_id).get();
2567 if (!symtab)
2568 return 0;
2569
2570 // sh_link points to associated string table.
2571 Section *strtab = section_list->FindSectionByID(sym_hdr->sh_link).get();
2572 if (!strtab)
2573 return 0;
2574
2575 DataExtractor rel_data;
2576 if (!ReadSectionData(rel_section, rel_data))
2577 return 0;
2578
2579 DataExtractor symtab_data;
2580 if (!ReadSectionData(symtab, symtab_data))
2581 return 0;
2582
2583 DataExtractor strtab_data;
2584 if (!ReadSectionData(strtab, strtab_data))
2585 return 0;
2586
2587 unsigned rel_type = PLTRelocationType();
2588 if (!rel_type)
2589 return 0;
2590
2591 return ParsePLTRelocations(symbol_table, start_id, rel_type, &m_header,
2592 rel_hdr, plt_hdr, sym_hdr, plt_section_sp,
2593 rel_data, symtab_data, strtab_data);
2594 }
2595
ApplyELF64ABS64Relocation(Symtab * symtab,ELFRelocation & rel,DataExtractor & debug_data,Section * rel_section)2596 static void ApplyELF64ABS64Relocation(Symtab *symtab, ELFRelocation &rel,
2597 DataExtractor &debug_data,
2598 Section *rel_section) {
2599 Symbol *symbol = symtab->FindSymbolByID(ELFRelocation::RelocSymbol64(rel));
2600 if (symbol) {
2601 addr_t value = symbol->GetAddressRef().GetFileAddress();
2602 DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2603 // ObjectFileELF creates a WritableDataBuffer in CreateInstance.
2604 WritableDataBuffer *data_buffer =
2605 llvm::cast<WritableDataBuffer>(data_buffer_sp.get());
2606 uint64_t *dst = reinterpret_cast<uint64_t *>(
2607 data_buffer->GetBytes() + rel_section->GetFileOffset() +
2608 ELFRelocation::RelocOffset64(rel));
2609 uint64_t val_offset = value + ELFRelocation::RelocAddend64(rel);
2610 memcpy(dst, &val_offset, sizeof(uint64_t));
2611 }
2612 }
2613
ApplyELF64ABS32Relocation(Symtab * symtab,ELFRelocation & rel,DataExtractor & debug_data,Section * rel_section,bool is_signed)2614 static void ApplyELF64ABS32Relocation(Symtab *symtab, ELFRelocation &rel,
2615 DataExtractor &debug_data,
2616 Section *rel_section, bool is_signed) {
2617 Symbol *symbol = symtab->FindSymbolByID(ELFRelocation::RelocSymbol64(rel));
2618 if (symbol) {
2619 addr_t value = symbol->GetAddressRef().GetFileAddress();
2620 value += ELFRelocation::RelocAddend32(rel);
2621 if ((!is_signed && (value > UINT32_MAX)) ||
2622 (is_signed &&
2623 ((int64_t)value > INT32_MAX || (int64_t)value < INT32_MIN))) {
2624 Log *log = GetLog(LLDBLog::Modules);
2625 LLDB_LOGF(log, "Failed to apply debug info relocations");
2626 return;
2627 }
2628 uint32_t truncated_addr = (value & 0xFFFFFFFF);
2629 DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2630 // ObjectFileELF creates a WritableDataBuffer in CreateInstance.
2631 WritableDataBuffer *data_buffer =
2632 llvm::cast<WritableDataBuffer>(data_buffer_sp.get());
2633 uint32_t *dst = reinterpret_cast<uint32_t *>(
2634 data_buffer->GetBytes() + rel_section->GetFileOffset() +
2635 ELFRelocation::RelocOffset32(rel));
2636 memcpy(dst, &truncated_addr, sizeof(uint32_t));
2637 }
2638 }
2639
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)2640 unsigned ObjectFileELF::ApplyRelocations(
2641 Symtab *symtab, const ELFHeader *hdr, const ELFSectionHeader *rel_hdr,
2642 const ELFSectionHeader *symtab_hdr, const ELFSectionHeader *debug_hdr,
2643 DataExtractor &rel_data, DataExtractor &symtab_data,
2644 DataExtractor &debug_data, Section *rel_section) {
2645 ELFRelocation rel(rel_hdr->sh_type);
2646 lldb::addr_t offset = 0;
2647 const unsigned num_relocations = rel_hdr->sh_size / rel_hdr->sh_entsize;
2648 typedef unsigned (*reloc_info_fn)(const ELFRelocation &rel);
2649 reloc_info_fn reloc_type;
2650 reloc_info_fn reloc_symbol;
2651
2652 if (hdr->Is32Bit()) {
2653 reloc_type = ELFRelocation::RelocType32;
2654 reloc_symbol = ELFRelocation::RelocSymbol32;
2655 } else {
2656 reloc_type = ELFRelocation::RelocType64;
2657 reloc_symbol = ELFRelocation::RelocSymbol64;
2658 }
2659
2660 for (unsigned i = 0; i < num_relocations; ++i) {
2661 if (!rel.Parse(rel_data, &offset)) {
2662 GetModule()->ReportError(".rel{0}[{1:d}] failed to parse relocation",
2663 rel_section->GetName().AsCString(), i);
2664 break;
2665 }
2666 Symbol *symbol = nullptr;
2667
2668 if (hdr->Is32Bit()) {
2669 switch (reloc_type(rel)) {
2670 case R_386_32:
2671 symbol = symtab->FindSymbolByID(reloc_symbol(rel));
2672 if (symbol) {
2673 addr_t f_offset =
2674 rel_section->GetFileOffset() + ELFRelocation::RelocOffset32(rel);
2675 DataBufferSP &data_buffer_sp = debug_data.GetSharedDataBuffer();
2676 // ObjectFileELF creates a WritableDataBuffer in CreateInstance.
2677 WritableDataBuffer *data_buffer =
2678 llvm::cast<WritableDataBuffer>(data_buffer_sp.get());
2679 uint32_t *dst = reinterpret_cast<uint32_t *>(
2680 data_buffer->GetBytes() + f_offset);
2681
2682 addr_t value = symbol->GetAddressRef().GetFileAddress();
2683 if (rel.IsRela()) {
2684 value += ELFRelocation::RelocAddend32(rel);
2685 } else {
2686 value += *dst;
2687 }
2688 *dst = value;
2689 } else {
2690 GetModule()->ReportError(".rel{0}[{1}] unknown symbol id: {2:d}",
2691 rel_section->GetName().AsCString(), i,
2692 reloc_symbol(rel));
2693 }
2694 break;
2695 case R_386_PC32:
2696 default:
2697 GetModule()->ReportError("unsupported 32-bit relocation:"
2698 " .rel{0}[{1}], type {2}",
2699 rel_section->GetName().AsCString(), i,
2700 reloc_type(rel));
2701 }
2702 } else {
2703 switch (hdr->e_machine) {
2704 case llvm::ELF::EM_AARCH64:
2705 switch (reloc_type(rel)) {
2706 case R_AARCH64_ABS64:
2707 ApplyELF64ABS64Relocation(symtab, rel, debug_data, rel_section);
2708 break;
2709 case R_AARCH64_ABS32:
2710 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section, true);
2711 break;
2712 default:
2713 assert(false && "unexpected relocation type");
2714 }
2715 break;
2716 case llvm::ELF::EM_LOONGARCH:
2717 switch (reloc_type(rel)) {
2718 case R_LARCH_64:
2719 ApplyELF64ABS64Relocation(symtab, rel, debug_data, rel_section);
2720 break;
2721 case R_LARCH_32:
2722 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section, true);
2723 break;
2724 default:
2725 assert(false && "unexpected relocation type");
2726 }
2727 break;
2728 case llvm::ELF::EM_X86_64:
2729 switch (reloc_type(rel)) {
2730 case R_X86_64_64:
2731 ApplyELF64ABS64Relocation(symtab, rel, debug_data, rel_section);
2732 break;
2733 case R_X86_64_32:
2734 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section,
2735 false);
2736 break;
2737 case R_X86_64_32S:
2738 ApplyELF64ABS32Relocation(symtab, rel, debug_data, rel_section, true);
2739 break;
2740 case R_X86_64_PC32:
2741 default:
2742 assert(false && "unexpected relocation type");
2743 }
2744 break;
2745 default:
2746 assert(false && "unsupported machine");
2747 }
2748 }
2749 }
2750
2751 return 0;
2752 }
2753
RelocateDebugSections(const ELFSectionHeader * rel_hdr,user_id_t rel_id,lldb_private::Symtab * thetab)2754 unsigned ObjectFileELF::RelocateDebugSections(const ELFSectionHeader *rel_hdr,
2755 user_id_t rel_id,
2756 lldb_private::Symtab *thetab) {
2757 assert(rel_hdr->sh_type == SHT_RELA || rel_hdr->sh_type == SHT_REL);
2758
2759 // Parse in the section list if needed.
2760 SectionList *section_list = GetSectionList();
2761 if (!section_list)
2762 return 0;
2763
2764 user_id_t symtab_id = rel_hdr->sh_link;
2765 user_id_t debug_id = rel_hdr->sh_info;
2766
2767 const ELFSectionHeader *symtab_hdr = GetSectionHeaderByIndex(symtab_id);
2768 if (!symtab_hdr)
2769 return 0;
2770
2771 const ELFSectionHeader *debug_hdr = GetSectionHeaderByIndex(debug_id);
2772 if (!debug_hdr)
2773 return 0;
2774
2775 Section *rel = section_list->FindSectionByID(rel_id).get();
2776 if (!rel)
2777 return 0;
2778
2779 Section *symtab = section_list->FindSectionByID(symtab_id).get();
2780 if (!symtab)
2781 return 0;
2782
2783 Section *debug = section_list->FindSectionByID(debug_id).get();
2784 if (!debug)
2785 return 0;
2786
2787 DataExtractor rel_data;
2788 DataExtractor symtab_data;
2789 DataExtractor debug_data;
2790
2791 if (GetData(rel->GetFileOffset(), rel->GetFileSize(), rel_data) &&
2792 GetData(symtab->GetFileOffset(), symtab->GetFileSize(), symtab_data) &&
2793 GetData(debug->GetFileOffset(), debug->GetFileSize(), debug_data)) {
2794 ApplyRelocations(thetab, &m_header, rel_hdr, symtab_hdr, debug_hdr,
2795 rel_data, symtab_data, debug_data, debug);
2796 }
2797
2798 return 0;
2799 }
2800
ParseSymtab(Symtab & lldb_symtab)2801 void ObjectFileELF::ParseSymtab(Symtab &lldb_symtab) {
2802 ModuleSP module_sp(GetModule());
2803 if (!module_sp)
2804 return;
2805
2806 Progress progress(
2807 llvm::formatv("Parsing symbol table for {0}",
2808 m_file.GetFilename().AsCString("<Unknown>")));
2809 ElapsedTime elapsed(module_sp->GetSymtabParseTime());
2810
2811 // We always want to use the main object file so we (hopefully) only have one
2812 // cached copy of our symtab, dynamic sections, etc.
2813 ObjectFile *module_obj_file = module_sp->GetObjectFile();
2814 if (module_obj_file && module_obj_file != this)
2815 return module_obj_file->ParseSymtab(lldb_symtab);
2816
2817 SectionList *section_list = module_sp->GetSectionList();
2818 if (!section_list)
2819 return;
2820
2821 uint64_t symbol_id = 0;
2822
2823 // Sharable objects and dynamic executables usually have 2 distinct symbol
2824 // tables, one named ".symtab", and the other ".dynsym". The dynsym is a
2825 // smaller version of the symtab that only contains global symbols. The
2826 // information found in the dynsym is therefore also found in the symtab,
2827 // while the reverse is not necessarily true.
2828 Section *symtab =
2829 section_list->FindSectionByType(eSectionTypeELFSymbolTable, true).get();
2830 if (symtab)
2831 symbol_id += ParseSymbolTable(&lldb_symtab, symbol_id, symtab);
2832
2833 // The symtab section is non-allocable and can be stripped, while the
2834 // .dynsym section which should always be always be there. To support the
2835 // minidebuginfo case we parse .dynsym when there's a .gnu_debuginfo
2836 // section, nomatter if .symtab was already parsed or not. This is because
2837 // minidebuginfo normally removes the .symtab symbols which have their
2838 // matching .dynsym counterparts.
2839 if (!symtab ||
2840 GetSectionList()->FindSectionByName(ConstString(".gnu_debugdata"))) {
2841 Section *dynsym =
2842 section_list->FindSectionByType(eSectionTypeELFDynamicSymbols, true)
2843 .get();
2844 if (dynsym)
2845 symbol_id += ParseSymbolTable(&lldb_symtab, symbol_id, dynsym);
2846 }
2847
2848 // DT_JMPREL
2849 // If present, this entry's d_ptr member holds the address of
2850 // relocation
2851 // entries associated solely with the procedure linkage table.
2852 // Separating
2853 // these relocation entries lets the dynamic linker ignore them during
2854 // process initialization, if lazy binding is enabled. If this entry is
2855 // present, the related entries of types DT_PLTRELSZ and DT_PLTREL must
2856 // also be present.
2857 const ELFDynamic *symbol = FindDynamicSymbol(DT_JMPREL);
2858 if (symbol) {
2859 const ELFDynamic *pltrelsz = FindDynamicSymbol(DT_PLTRELSZ);
2860 assert(pltrelsz != NULL);
2861 // Synthesize trampoline symbols to help navigate the PLT.
2862 addr_t addr = symbol->d_ptr;
2863 Section *reloc_section =
2864 section_list->FindSectionContainingFileAddress(addr).get();
2865 if (reloc_section && pltrelsz->d_val > 0) {
2866 user_id_t reloc_id = reloc_section->GetID();
2867 const ELFSectionHeaderInfo *reloc_header =
2868 GetSectionHeaderByIndex(reloc_id);
2869 if (reloc_header)
2870 ParseTrampolineSymbols(&lldb_symtab, symbol_id, reloc_header, reloc_id);
2871 }
2872 }
2873
2874 if (DWARFCallFrameInfo *eh_frame =
2875 GetModule()->GetUnwindTable().GetEHFrameInfo()) {
2876 ParseUnwindSymbols(&lldb_symtab, eh_frame);
2877 }
2878
2879 // In the event that there's no symbol entry for the entry point we'll
2880 // artificially create one. We delegate to the symtab object the figuring
2881 // out of the proper size, this will usually make it span til the next
2882 // symbol it finds in the section. This means that if there are missing
2883 // symbols the entry point might span beyond its function definition.
2884 // We're fine with this as it doesn't make it worse than not having a
2885 // symbol entry at all.
2886 if (CalculateType() == eTypeExecutable) {
2887 ArchSpec arch = GetArchitecture();
2888 auto entry_point_addr = GetEntryPointAddress();
2889 bool is_valid_entry_point =
2890 entry_point_addr.IsValid() && entry_point_addr.IsSectionOffset();
2891 addr_t entry_point_file_addr = entry_point_addr.GetFileAddress();
2892 if (is_valid_entry_point && !lldb_symtab.FindSymbolContainingFileAddress(
2893 entry_point_file_addr)) {
2894 uint64_t symbol_id = lldb_symtab.GetNumSymbols();
2895 // Don't set the name for any synthetic symbols, the Symbol
2896 // object will generate one if needed when the name is accessed
2897 // via accessors.
2898 SectionSP section_sp = entry_point_addr.GetSection();
2899 Symbol symbol(
2900 /*symID=*/symbol_id,
2901 /*name=*/llvm::StringRef(), // Name will be auto generated.
2902 /*type=*/eSymbolTypeCode,
2903 /*external=*/true,
2904 /*is_debug=*/false,
2905 /*is_trampoline=*/false,
2906 /*is_artificial=*/true,
2907 /*section_sp=*/section_sp,
2908 /*offset=*/0,
2909 /*size=*/0, // FDE can span multiple symbols so don't use its size.
2910 /*size_is_valid=*/false,
2911 /*contains_linker_annotations=*/false,
2912 /*flags=*/0);
2913 // When the entry point is arm thumb we need to explicitly set its
2914 // class address to reflect that. This is important because expression
2915 // evaluation relies on correctly setting a breakpoint at this
2916 // address.
2917 if (arch.GetMachine() == llvm::Triple::arm &&
2918 (entry_point_file_addr & 1)) {
2919 symbol.GetAddressRef().SetOffset(entry_point_addr.GetOffset() ^ 1);
2920 m_address_class_map[entry_point_file_addr ^ 1] =
2921 AddressClass::eCodeAlternateISA;
2922 } else {
2923 m_address_class_map[entry_point_file_addr] = AddressClass::eCode;
2924 }
2925 lldb_symtab.AddSymbol(symbol);
2926 }
2927 }
2928 }
2929
RelocateSection(lldb_private::Section * section)2930 void ObjectFileELF::RelocateSection(lldb_private::Section *section)
2931 {
2932 static const char *debug_prefix = ".debug";
2933
2934 // Set relocated bit so we stop getting called, regardless of whether we
2935 // actually relocate.
2936 section->SetIsRelocated(true);
2937
2938 // We only relocate in ELF relocatable files
2939 if (CalculateType() != eTypeObjectFile)
2940 return;
2941
2942 const char *section_name = section->GetName().GetCString();
2943 // Can't relocate that which can't be named
2944 if (section_name == nullptr)
2945 return;
2946
2947 // We don't relocate non-debug sections at the moment
2948 if (strncmp(section_name, debug_prefix, strlen(debug_prefix)))
2949 return;
2950
2951 // Relocation section names to look for
2952 std::string needle = std::string(".rel") + section_name;
2953 std::string needlea = std::string(".rela") + section_name;
2954
2955 for (SectionHeaderCollIter I = m_section_headers.begin();
2956 I != m_section_headers.end(); ++I) {
2957 if (I->sh_type == SHT_RELA || I->sh_type == SHT_REL) {
2958 const char *hay_name = I->section_name.GetCString();
2959 if (hay_name == nullptr)
2960 continue;
2961 if (needle == hay_name || needlea == hay_name) {
2962 const ELFSectionHeader &reloc_header = *I;
2963 user_id_t reloc_id = SectionIndex(I);
2964 RelocateDebugSections(&reloc_header, reloc_id, GetSymtab());
2965 break;
2966 }
2967 }
2968 }
2969 }
2970
ParseUnwindSymbols(Symtab * symbol_table,DWARFCallFrameInfo * eh_frame)2971 void ObjectFileELF::ParseUnwindSymbols(Symtab *symbol_table,
2972 DWARFCallFrameInfo *eh_frame) {
2973 SectionList *section_list = GetSectionList();
2974 if (!section_list)
2975 return;
2976
2977 // First we save the new symbols into a separate list and add them to the
2978 // symbol table after we collected all symbols we want to add. This is
2979 // neccessary because adding a new symbol invalidates the internal index of
2980 // the symtab what causing the next lookup to be slow because it have to
2981 // recalculate the index first.
2982 std::vector<Symbol> new_symbols;
2983
2984 size_t num_symbols = symbol_table->GetNumSymbols();
2985 uint64_t last_symbol_id =
2986 num_symbols ? symbol_table->SymbolAtIndex(num_symbols - 1)->GetID() : 0;
2987 eh_frame->ForEachFDEEntries([&](lldb::addr_t file_addr, uint32_t size,
2988 dw_offset_t) {
2989 Symbol *symbol = symbol_table->FindSymbolAtFileAddress(file_addr);
2990 if (symbol) {
2991 if (!symbol->GetByteSizeIsValid()) {
2992 symbol->SetByteSize(size);
2993 symbol->SetSizeIsSynthesized(true);
2994 }
2995 } else {
2996 SectionSP section_sp =
2997 section_list->FindSectionContainingFileAddress(file_addr);
2998 if (section_sp) {
2999 addr_t offset = file_addr - section_sp->GetFileAddress();
3000 uint64_t symbol_id = ++last_symbol_id;
3001 // Don't set the name for any synthetic symbols, the Symbol
3002 // object will generate one if needed when the name is accessed
3003 // via accessors.
3004 Symbol eh_symbol(
3005 /*symID=*/symbol_id,
3006 /*name=*/llvm::StringRef(), // Name will be auto generated.
3007 /*type=*/eSymbolTypeCode,
3008 /*external=*/true,
3009 /*is_debug=*/false,
3010 /*is_trampoline=*/false,
3011 /*is_artificial=*/true,
3012 /*section_sp=*/section_sp,
3013 /*offset=*/offset,
3014 /*size=*/0, // FDE can span multiple symbols so don't use its size.
3015 /*size_is_valid=*/false,
3016 /*contains_linker_annotations=*/false,
3017 /*flags=*/0);
3018 new_symbols.push_back(eh_symbol);
3019 }
3020 }
3021 return true;
3022 });
3023
3024 for (const Symbol &s : new_symbols)
3025 symbol_table->AddSymbol(s);
3026 }
3027
IsStripped()3028 bool ObjectFileELF::IsStripped() {
3029 // TODO: determine this for ELF
3030 return false;
3031 }
3032
3033 //===----------------------------------------------------------------------===//
3034 // Dump
3035 //
3036 // Dump the specifics of the runtime file container (such as any headers
3037 // segments, sections, etc).
Dump(Stream * s)3038 void ObjectFileELF::Dump(Stream *s) {
3039 ModuleSP module_sp(GetModule());
3040 if (!module_sp) {
3041 return;
3042 }
3043
3044 std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
3045 s->Printf("%p: ", static_cast<void *>(this));
3046 s->Indent();
3047 s->PutCString("ObjectFileELF");
3048
3049 ArchSpec header_arch = GetArchitecture();
3050
3051 *s << ", file = '" << m_file
3052 << "', arch = " << header_arch.GetArchitectureName() << "\n";
3053
3054 DumpELFHeader(s, m_header);
3055 s->EOL();
3056 DumpELFProgramHeaders(s);
3057 s->EOL();
3058 DumpELFSectionHeaders(s);
3059 s->EOL();
3060 SectionList *section_list = GetSectionList();
3061 if (section_list)
3062 section_list->Dump(s->AsRawOstream(), s->GetIndentLevel(), nullptr, true,
3063 UINT32_MAX);
3064 Symtab *symtab = GetSymtab();
3065 if (symtab)
3066 symtab->Dump(s, nullptr, eSortOrderNone);
3067 s->EOL();
3068 DumpDependentModules(s);
3069 s->EOL();
3070 }
3071
3072 // DumpELFHeader
3073 //
3074 // Dump the ELF header to the specified output stream
DumpELFHeader(Stream * s,const ELFHeader & header)3075 void ObjectFileELF::DumpELFHeader(Stream *s, const ELFHeader &header) {
3076 s->PutCString("ELF Header\n");
3077 s->Printf("e_ident[EI_MAG0 ] = 0x%2.2x\n", header.e_ident[EI_MAG0]);
3078 s->Printf("e_ident[EI_MAG1 ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG1],
3079 header.e_ident[EI_MAG1]);
3080 s->Printf("e_ident[EI_MAG2 ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG2],
3081 header.e_ident[EI_MAG2]);
3082 s->Printf("e_ident[EI_MAG3 ] = 0x%2.2x '%c'\n", header.e_ident[EI_MAG3],
3083 header.e_ident[EI_MAG3]);
3084
3085 s->Printf("e_ident[EI_CLASS ] = 0x%2.2x\n", header.e_ident[EI_CLASS]);
3086 s->Printf("e_ident[EI_DATA ] = 0x%2.2x ", header.e_ident[EI_DATA]);
3087 DumpELFHeader_e_ident_EI_DATA(s, header.e_ident[EI_DATA]);
3088 s->Printf("\ne_ident[EI_VERSION] = 0x%2.2x\n", header.e_ident[EI_VERSION]);
3089 s->Printf("e_ident[EI_PAD ] = 0x%2.2x\n", header.e_ident[EI_PAD]);
3090
3091 s->Printf("e_type = 0x%4.4x ", header.e_type);
3092 DumpELFHeader_e_type(s, header.e_type);
3093 s->Printf("\ne_machine = 0x%4.4x\n", header.e_machine);
3094 s->Printf("e_version = 0x%8.8x\n", header.e_version);
3095 s->Printf("e_entry = 0x%8.8" PRIx64 "\n", header.e_entry);
3096 s->Printf("e_phoff = 0x%8.8" PRIx64 "\n", header.e_phoff);
3097 s->Printf("e_shoff = 0x%8.8" PRIx64 "\n", header.e_shoff);
3098 s->Printf("e_flags = 0x%8.8x\n", header.e_flags);
3099 s->Printf("e_ehsize = 0x%4.4x\n", header.e_ehsize);
3100 s->Printf("e_phentsize = 0x%4.4x\n", header.e_phentsize);
3101 s->Printf("e_phnum = 0x%8.8x\n", header.e_phnum);
3102 s->Printf("e_shentsize = 0x%4.4x\n", header.e_shentsize);
3103 s->Printf("e_shnum = 0x%8.8x\n", header.e_shnum);
3104 s->Printf("e_shstrndx = 0x%8.8x\n", header.e_shstrndx);
3105 }
3106
3107 // DumpELFHeader_e_type
3108 //
3109 // Dump an token value for the ELF header member e_type
DumpELFHeader_e_type(Stream * s,elf_half e_type)3110 void ObjectFileELF::DumpELFHeader_e_type(Stream *s, elf_half e_type) {
3111 switch (e_type) {
3112 case ET_NONE:
3113 *s << "ET_NONE";
3114 break;
3115 case ET_REL:
3116 *s << "ET_REL";
3117 break;
3118 case ET_EXEC:
3119 *s << "ET_EXEC";
3120 break;
3121 case ET_DYN:
3122 *s << "ET_DYN";
3123 break;
3124 case ET_CORE:
3125 *s << "ET_CORE";
3126 break;
3127 default:
3128 break;
3129 }
3130 }
3131
3132 // DumpELFHeader_e_ident_EI_DATA
3133 //
3134 // Dump an token value for the ELF header member e_ident[EI_DATA]
DumpELFHeader_e_ident_EI_DATA(Stream * s,unsigned char ei_data)3135 void ObjectFileELF::DumpELFHeader_e_ident_EI_DATA(Stream *s,
3136 unsigned char ei_data) {
3137 switch (ei_data) {
3138 case ELFDATANONE:
3139 *s << "ELFDATANONE";
3140 break;
3141 case ELFDATA2LSB:
3142 *s << "ELFDATA2LSB - Little Endian";
3143 break;
3144 case ELFDATA2MSB:
3145 *s << "ELFDATA2MSB - Big Endian";
3146 break;
3147 default:
3148 break;
3149 }
3150 }
3151
3152 // DumpELFProgramHeader
3153 //
3154 // Dump a single ELF program header to the specified output stream
DumpELFProgramHeader(Stream * s,const ELFProgramHeader & ph)3155 void ObjectFileELF::DumpELFProgramHeader(Stream *s,
3156 const ELFProgramHeader &ph) {
3157 DumpELFProgramHeader_p_type(s, ph.p_type);
3158 s->Printf(" %8.8" PRIx64 " %8.8" PRIx64 " %8.8" PRIx64, ph.p_offset,
3159 ph.p_vaddr, ph.p_paddr);
3160 s->Printf(" %8.8" PRIx64 " %8.8" PRIx64 " %8.8x (", ph.p_filesz, ph.p_memsz,
3161 ph.p_flags);
3162
3163 DumpELFProgramHeader_p_flags(s, ph.p_flags);
3164 s->Printf(") %8.8" PRIx64, ph.p_align);
3165 }
3166
3167 // DumpELFProgramHeader_p_type
3168 //
3169 // Dump an token value for the ELF program header member p_type which describes
3170 // the type of the program header
DumpELFProgramHeader_p_type(Stream * s,elf_word p_type)3171 void ObjectFileELF::DumpELFProgramHeader_p_type(Stream *s, elf_word p_type) {
3172 const int kStrWidth = 15;
3173 switch (p_type) {
3174 CASE_AND_STREAM(s, PT_NULL, kStrWidth);
3175 CASE_AND_STREAM(s, PT_LOAD, kStrWidth);
3176 CASE_AND_STREAM(s, PT_DYNAMIC, kStrWidth);
3177 CASE_AND_STREAM(s, PT_INTERP, kStrWidth);
3178 CASE_AND_STREAM(s, PT_NOTE, kStrWidth);
3179 CASE_AND_STREAM(s, PT_SHLIB, kStrWidth);
3180 CASE_AND_STREAM(s, PT_PHDR, kStrWidth);
3181 CASE_AND_STREAM(s, PT_TLS, kStrWidth);
3182 CASE_AND_STREAM(s, PT_GNU_EH_FRAME, kStrWidth);
3183 default:
3184 s->Printf("0x%8.8x%*s", p_type, kStrWidth - 10, "");
3185 break;
3186 }
3187 }
3188
3189 // DumpELFProgramHeader_p_flags
3190 //
3191 // Dump an token value for the ELF program header member p_flags
DumpELFProgramHeader_p_flags(Stream * s,elf_word p_flags)3192 void ObjectFileELF::DumpELFProgramHeader_p_flags(Stream *s, elf_word p_flags) {
3193 *s << ((p_flags & PF_X) ? "PF_X" : " ")
3194 << (((p_flags & PF_X) && (p_flags & PF_W)) ? '+' : ' ')
3195 << ((p_flags & PF_W) ? "PF_W" : " ")
3196 << (((p_flags & PF_W) && (p_flags & PF_R)) ? '+' : ' ')
3197 << ((p_flags & PF_R) ? "PF_R" : " ");
3198 }
3199
3200 // DumpELFProgramHeaders
3201 //
3202 // Dump all of the ELF program header to the specified output stream
DumpELFProgramHeaders(Stream * s)3203 void ObjectFileELF::DumpELFProgramHeaders(Stream *s) {
3204 if (!ParseProgramHeaders())
3205 return;
3206
3207 s->PutCString("Program Headers\n");
3208 s->PutCString("IDX p_type p_offset p_vaddr p_paddr "
3209 "p_filesz p_memsz p_flags p_align\n");
3210 s->PutCString("==== --------------- -------- -------- -------- "
3211 "-------- -------- ------------------------- --------\n");
3212
3213 for (const auto &H : llvm::enumerate(m_program_headers)) {
3214 s->Format("[{0,2}] ", H.index());
3215 ObjectFileELF::DumpELFProgramHeader(s, H.value());
3216 s->EOL();
3217 }
3218 }
3219
3220 // DumpELFSectionHeader
3221 //
3222 // Dump a single ELF section header to the specified output stream
DumpELFSectionHeader(Stream * s,const ELFSectionHeaderInfo & sh)3223 void ObjectFileELF::DumpELFSectionHeader(Stream *s,
3224 const ELFSectionHeaderInfo &sh) {
3225 s->Printf("%8.8x ", sh.sh_name);
3226 DumpELFSectionHeader_sh_type(s, sh.sh_type);
3227 s->Printf(" %8.8" PRIx64 " (", sh.sh_flags);
3228 DumpELFSectionHeader_sh_flags(s, sh.sh_flags);
3229 s->Printf(") %8.8" PRIx64 " %8.8" PRIx64 " %8.8" PRIx64, sh.sh_addr,
3230 sh.sh_offset, sh.sh_size);
3231 s->Printf(" %8.8x %8.8x", sh.sh_link, sh.sh_info);
3232 s->Printf(" %8.8" PRIx64 " %8.8" PRIx64, sh.sh_addralign, sh.sh_entsize);
3233 }
3234
3235 // DumpELFSectionHeader_sh_type
3236 //
3237 // Dump an token value for the ELF section header member sh_type which
3238 // describes the type of the section
DumpELFSectionHeader_sh_type(Stream * s,elf_word sh_type)3239 void ObjectFileELF::DumpELFSectionHeader_sh_type(Stream *s, elf_word sh_type) {
3240 const int kStrWidth = 12;
3241 switch (sh_type) {
3242 CASE_AND_STREAM(s, SHT_NULL, kStrWidth);
3243 CASE_AND_STREAM(s, SHT_PROGBITS, kStrWidth);
3244 CASE_AND_STREAM(s, SHT_SYMTAB, kStrWidth);
3245 CASE_AND_STREAM(s, SHT_STRTAB, kStrWidth);
3246 CASE_AND_STREAM(s, SHT_RELA, kStrWidth);
3247 CASE_AND_STREAM(s, SHT_HASH, kStrWidth);
3248 CASE_AND_STREAM(s, SHT_DYNAMIC, kStrWidth);
3249 CASE_AND_STREAM(s, SHT_NOTE, kStrWidth);
3250 CASE_AND_STREAM(s, SHT_NOBITS, kStrWidth);
3251 CASE_AND_STREAM(s, SHT_REL, kStrWidth);
3252 CASE_AND_STREAM(s, SHT_SHLIB, kStrWidth);
3253 CASE_AND_STREAM(s, SHT_DYNSYM, kStrWidth);
3254 CASE_AND_STREAM(s, SHT_LOPROC, kStrWidth);
3255 CASE_AND_STREAM(s, SHT_HIPROC, kStrWidth);
3256 CASE_AND_STREAM(s, SHT_LOUSER, kStrWidth);
3257 CASE_AND_STREAM(s, SHT_HIUSER, kStrWidth);
3258 default:
3259 s->Printf("0x%8.8x%*s", sh_type, kStrWidth - 10, "");
3260 break;
3261 }
3262 }
3263
3264 // DumpELFSectionHeader_sh_flags
3265 //
3266 // Dump an token value for the ELF section header member sh_flags
DumpELFSectionHeader_sh_flags(Stream * s,elf_xword sh_flags)3267 void ObjectFileELF::DumpELFSectionHeader_sh_flags(Stream *s,
3268 elf_xword sh_flags) {
3269 *s << ((sh_flags & SHF_WRITE) ? "WRITE" : " ")
3270 << (((sh_flags & SHF_WRITE) && (sh_flags & SHF_ALLOC)) ? '+' : ' ')
3271 << ((sh_flags & SHF_ALLOC) ? "ALLOC" : " ")
3272 << (((sh_flags & SHF_ALLOC) && (sh_flags & SHF_EXECINSTR)) ? '+' : ' ')
3273 << ((sh_flags & SHF_EXECINSTR) ? "EXECINSTR" : " ");
3274 }
3275
3276 // DumpELFSectionHeaders
3277 //
3278 // Dump all of the ELF section header to the specified output stream
DumpELFSectionHeaders(Stream * s)3279 void ObjectFileELF::DumpELFSectionHeaders(Stream *s) {
3280 if (!ParseSectionHeaders())
3281 return;
3282
3283 s->PutCString("Section Headers\n");
3284 s->PutCString("IDX name type flags "
3285 "addr offset size link info addralgn "
3286 "entsize Name\n");
3287 s->PutCString("==== -------- ------------ -------------------------------- "
3288 "-------- -------- -------- -------- -------- -------- "
3289 "-------- ====================\n");
3290
3291 uint32_t idx = 0;
3292 for (SectionHeaderCollConstIter I = m_section_headers.begin();
3293 I != m_section_headers.end(); ++I, ++idx) {
3294 s->Printf("[%2u] ", idx);
3295 ObjectFileELF::DumpELFSectionHeader(s, *I);
3296 const char *section_name = I->section_name.AsCString("");
3297 if (section_name)
3298 *s << ' ' << section_name << "\n";
3299 }
3300 }
3301
DumpDependentModules(lldb_private::Stream * s)3302 void ObjectFileELF::DumpDependentModules(lldb_private::Stream *s) {
3303 size_t num_modules = ParseDependentModules();
3304
3305 if (num_modules > 0) {
3306 s->PutCString("Dependent Modules:\n");
3307 for (unsigned i = 0; i < num_modules; ++i) {
3308 const FileSpec &spec = m_filespec_up->GetFileSpecAtIndex(i);
3309 s->Printf(" %s\n", spec.GetFilename().GetCString());
3310 }
3311 }
3312 }
3313
GetArchitecture()3314 ArchSpec ObjectFileELF::GetArchitecture() {
3315 if (!ParseHeader())
3316 return ArchSpec();
3317
3318 if (m_section_headers.empty()) {
3319 // Allow elf notes to be parsed which may affect the detected architecture.
3320 ParseSectionHeaders();
3321 }
3322
3323 if (CalculateType() == eTypeCoreFile &&
3324 !m_arch_spec.TripleOSWasSpecified()) {
3325 // Core files don't have section headers yet they have PT_NOTE program
3326 // headers that might shed more light on the architecture
3327 for (const elf::ELFProgramHeader &H : ProgramHeaders()) {
3328 if (H.p_type != PT_NOTE || H.p_offset == 0 || H.p_filesz == 0)
3329 continue;
3330 DataExtractor data;
3331 if (data.SetData(m_data, H.p_offset, H.p_filesz) == H.p_filesz) {
3332 UUID uuid;
3333 RefineModuleDetailsFromNote(data, m_arch_spec, uuid);
3334 }
3335 }
3336 }
3337 return m_arch_spec;
3338 }
3339
CalculateType()3340 ObjectFile::Type ObjectFileELF::CalculateType() {
3341 switch (m_header.e_type) {
3342 case llvm::ELF::ET_NONE:
3343 // 0 - No file type
3344 return eTypeUnknown;
3345
3346 case llvm::ELF::ET_REL:
3347 // 1 - Relocatable file
3348 return eTypeObjectFile;
3349
3350 case llvm::ELF::ET_EXEC:
3351 // 2 - Executable file
3352 return eTypeExecutable;
3353
3354 case llvm::ELF::ET_DYN:
3355 // 3 - Shared object file
3356 return eTypeSharedLibrary;
3357
3358 case ET_CORE:
3359 // 4 - Core file
3360 return eTypeCoreFile;
3361
3362 default:
3363 break;
3364 }
3365 return eTypeUnknown;
3366 }
3367
CalculateStrata()3368 ObjectFile::Strata ObjectFileELF::CalculateStrata() {
3369 switch (m_header.e_type) {
3370 case llvm::ELF::ET_NONE:
3371 // 0 - No file type
3372 return eStrataUnknown;
3373
3374 case llvm::ELF::ET_REL:
3375 // 1 - Relocatable file
3376 return eStrataUnknown;
3377
3378 case llvm::ELF::ET_EXEC:
3379 // 2 - Executable file
3380 // TODO: is there any way to detect that an executable is a kernel
3381 // related executable by inspecting the program headers, section headers,
3382 // symbols, or any other flag bits???
3383 return eStrataUser;
3384
3385 case llvm::ELF::ET_DYN:
3386 // 3 - Shared object file
3387 // TODO: is there any way to detect that an shared library is a kernel
3388 // related executable by inspecting the program headers, section headers,
3389 // symbols, or any other flag bits???
3390 return eStrataUnknown;
3391
3392 case ET_CORE:
3393 // 4 - Core file
3394 // TODO: is there any way to detect that an core file is a kernel
3395 // related executable by inspecting the program headers, section headers,
3396 // symbols, or any other flag bits???
3397 return eStrataUnknown;
3398
3399 default:
3400 break;
3401 }
3402 return eStrataUnknown;
3403 }
3404
ReadSectionData(Section * section,lldb::offset_t section_offset,void * dst,size_t dst_len)3405 size_t ObjectFileELF::ReadSectionData(Section *section,
3406 lldb::offset_t section_offset, void *dst,
3407 size_t dst_len) {
3408 // If some other objectfile owns this data, pass this to them.
3409 if (section->GetObjectFile() != this)
3410 return section->GetObjectFile()->ReadSectionData(section, section_offset,
3411 dst, dst_len);
3412
3413 if (!section->Test(SHF_COMPRESSED))
3414 return ObjectFile::ReadSectionData(section, section_offset, dst, dst_len);
3415
3416 // For compressed sections we need to read to full data to be able to
3417 // decompress.
3418 DataExtractor data;
3419 ReadSectionData(section, data);
3420 return data.CopyData(section_offset, dst_len, dst);
3421 }
3422
ReadSectionData(Section * section,DataExtractor & section_data)3423 size_t ObjectFileELF::ReadSectionData(Section *section,
3424 DataExtractor §ion_data) {
3425 // If some other objectfile owns this data, pass this to them.
3426 if (section->GetObjectFile() != this)
3427 return section->GetObjectFile()->ReadSectionData(section, section_data);
3428
3429 size_t result = ObjectFile::ReadSectionData(section, section_data);
3430 if (result == 0 || !(section->Get() & llvm::ELF::SHF_COMPRESSED))
3431 return result;
3432
3433 auto Decompressor = llvm::object::Decompressor::create(
3434 section->GetName().GetStringRef(),
3435 {reinterpret_cast<const char *>(section_data.GetDataStart()),
3436 size_t(section_data.GetByteSize())},
3437 GetByteOrder() == eByteOrderLittle, GetAddressByteSize() == 8);
3438 if (!Decompressor) {
3439 GetModule()->ReportWarning(
3440 "Unable to initialize decompressor for section '{0}': {1}",
3441 section->GetName().GetCString(),
3442 llvm::toString(Decompressor.takeError()).c_str());
3443 section_data.Clear();
3444 return 0;
3445 }
3446
3447 auto buffer_sp =
3448 std::make_shared<DataBufferHeap>(Decompressor->getDecompressedSize(), 0);
3449 if (auto error = Decompressor->decompress(
3450 {buffer_sp->GetBytes(), size_t(buffer_sp->GetByteSize())})) {
3451 GetModule()->ReportWarning("Decompression of section '{0}' failed: {1}",
3452 section->GetName().GetCString(),
3453 llvm::toString(std::move(error)).c_str());
3454 section_data.Clear();
3455 return 0;
3456 }
3457
3458 section_data.SetData(buffer_sp);
3459 return buffer_sp->GetByteSize();
3460 }
3461
ProgramHeaders()3462 llvm::ArrayRef<ELFProgramHeader> ObjectFileELF::ProgramHeaders() {
3463 ParseProgramHeaders();
3464 return m_program_headers;
3465 }
3466
GetSegmentData(const ELFProgramHeader & H)3467 DataExtractor ObjectFileELF::GetSegmentData(const ELFProgramHeader &H) {
3468 return DataExtractor(m_data, H.p_offset, H.p_filesz);
3469 }
3470
AnySegmentHasPhysicalAddress()3471 bool ObjectFileELF::AnySegmentHasPhysicalAddress() {
3472 for (const ELFProgramHeader &H : ProgramHeaders()) {
3473 if (H.p_paddr != 0)
3474 return true;
3475 }
3476 return false;
3477 }
3478
3479 std::vector<ObjectFile::LoadableData>
GetLoadableData(Target & target)3480 ObjectFileELF::GetLoadableData(Target &target) {
3481 // Create a list of loadable data from loadable segments, using physical
3482 // addresses if they aren't all null
3483 std::vector<LoadableData> loadables;
3484 bool should_use_paddr = AnySegmentHasPhysicalAddress();
3485 for (const ELFProgramHeader &H : ProgramHeaders()) {
3486 LoadableData loadable;
3487 if (H.p_type != llvm::ELF::PT_LOAD)
3488 continue;
3489 loadable.Dest = should_use_paddr ? H.p_paddr : H.p_vaddr;
3490 if (loadable.Dest == LLDB_INVALID_ADDRESS)
3491 continue;
3492 if (H.p_filesz == 0)
3493 continue;
3494 auto segment_data = GetSegmentData(H);
3495 loadable.Contents = llvm::ArrayRef<uint8_t>(segment_data.GetDataStart(),
3496 segment_data.GetByteSize());
3497 loadables.push_back(loadable);
3498 }
3499 return loadables;
3500 }
3501
3502 lldb::WritableDataBufferSP
MapFileDataWritable(const FileSpec & file,uint64_t Size,uint64_t Offset)3503 ObjectFileELF::MapFileDataWritable(const FileSpec &file, uint64_t Size,
3504 uint64_t Offset) {
3505 return FileSystem::Instance().CreateWritableDataBuffer(file.GetPath(), Size,
3506 Offset);
3507 }
3508