1 //===- ELFObjectFile.cpp - ELF object file implementation -----------------===//
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 // Part of the ELFObjectFile class implementation.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/Object/ELFObjectFile.h"
14 #include "llvm/ADT/Triple.h"
15 #include "llvm/BinaryFormat/ELF.h"
16 #include "llvm/MC/MCInstrAnalysis.h"
17 #include "llvm/MC/SubtargetFeature.h"
18 #include "llvm/MC/TargetRegistry.h"
19 #include "llvm/Object/ELF.h"
20 #include "llvm/Object/ELFTypes.h"
21 #include "llvm/Object/Error.h"
22 #include "llvm/Support/ARMAttributeParser.h"
23 #include "llvm/Support/ARMBuildAttributes.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/MathExtras.h"
26 #include "llvm/Support/RISCVAttributeParser.h"
27 #include "llvm/Support/RISCVAttributes.h"
28 #include "llvm/Support/RISCVISAInfo.h"
29 #include <algorithm>
30 #include <cstddef>
31 #include <cstdint>
32 #include <memory>
33 #include <optional>
34 #include <string>
35 #include <utility>
36
37 using namespace llvm;
38 using namespace object;
39
40 const EnumEntry<unsigned> llvm::object::ElfSymbolTypes[NumElfSymbolTypes] = {
41 {"None", "NOTYPE", ELF::STT_NOTYPE},
42 {"Object", "OBJECT", ELF::STT_OBJECT},
43 {"Function", "FUNC", ELF::STT_FUNC},
44 {"Section", "SECTION", ELF::STT_SECTION},
45 {"File", "FILE", ELF::STT_FILE},
46 {"Common", "COMMON", ELF::STT_COMMON},
47 {"TLS", "TLS", ELF::STT_TLS},
48 {"Unknown", "<unknown>: 7", 7},
49 {"Unknown", "<unknown>: 8", 8},
50 {"Unknown", "<unknown>: 9", 9},
51 {"GNU_IFunc", "IFUNC", ELF::STT_GNU_IFUNC},
52 {"OS Specific", "<OS specific>: 11", 11},
53 {"OS Specific", "<OS specific>: 12", 12},
54 {"Proc Specific", "<processor specific>: 13", 13},
55 {"Proc Specific", "<processor specific>: 14", 14},
56 {"Proc Specific", "<processor specific>: 15", 15}
57 };
58
ELFObjectFileBase(unsigned int Type,MemoryBufferRef Source)59 ELFObjectFileBase::ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source)
60 : ObjectFile(Type, Source) {}
61
62 template <class ELFT>
63 static Expected<std::unique_ptr<ELFObjectFile<ELFT>>>
createPtr(MemoryBufferRef Object,bool InitContent)64 createPtr(MemoryBufferRef Object, bool InitContent) {
65 auto Ret = ELFObjectFile<ELFT>::create(Object, InitContent);
66 if (Error E = Ret.takeError())
67 return std::move(E);
68 return std::make_unique<ELFObjectFile<ELFT>>(std::move(*Ret));
69 }
70
71 Expected<std::unique_ptr<ObjectFile>>
createELFObjectFile(MemoryBufferRef Obj,bool InitContent)72 ObjectFile::createELFObjectFile(MemoryBufferRef Obj, bool InitContent) {
73 std::pair<unsigned char, unsigned char> Ident =
74 getElfArchType(Obj.getBuffer());
75 std::size_t MaxAlignment =
76 1ULL << countTrailingZeros(
77 reinterpret_cast<uintptr_t>(Obj.getBufferStart()));
78
79 if (MaxAlignment < 2)
80 return createError("Insufficient alignment");
81
82 if (Ident.first == ELF::ELFCLASS32) {
83 if (Ident.second == ELF::ELFDATA2LSB)
84 return createPtr<ELF32LE>(Obj, InitContent);
85 else if (Ident.second == ELF::ELFDATA2MSB)
86 return createPtr<ELF32BE>(Obj, InitContent);
87 else
88 return createError("Invalid ELF data");
89 } else if (Ident.first == ELF::ELFCLASS64) {
90 if (Ident.second == ELF::ELFDATA2LSB)
91 return createPtr<ELF64LE>(Obj, InitContent);
92 else if (Ident.second == ELF::ELFDATA2MSB)
93 return createPtr<ELF64BE>(Obj, InitContent);
94 else
95 return createError("Invalid ELF data");
96 }
97 return createError("Invalid ELF class");
98 }
99
getMIPSFeatures() const100 SubtargetFeatures ELFObjectFileBase::getMIPSFeatures() const {
101 SubtargetFeatures Features;
102 unsigned PlatformFlags = getPlatformFlags();
103
104 switch (PlatformFlags & ELF::EF_MIPS_ARCH) {
105 case ELF::EF_MIPS_ARCH_1:
106 break;
107 case ELF::EF_MIPS_ARCH_2:
108 Features.AddFeature("mips2");
109 break;
110 case ELF::EF_MIPS_ARCH_3:
111 Features.AddFeature("mips3");
112 break;
113 case ELF::EF_MIPS_ARCH_4:
114 Features.AddFeature("mips4");
115 break;
116 case ELF::EF_MIPS_ARCH_5:
117 Features.AddFeature("mips5");
118 break;
119 case ELF::EF_MIPS_ARCH_32:
120 Features.AddFeature("mips32");
121 break;
122 case ELF::EF_MIPS_ARCH_64:
123 Features.AddFeature("mips64");
124 break;
125 case ELF::EF_MIPS_ARCH_32R2:
126 Features.AddFeature("mips32r2");
127 break;
128 case ELF::EF_MIPS_ARCH_64R2:
129 Features.AddFeature("mips64r2");
130 break;
131 case ELF::EF_MIPS_ARCH_32R6:
132 Features.AddFeature("mips32r6");
133 break;
134 case ELF::EF_MIPS_ARCH_64R6:
135 Features.AddFeature("mips64r6");
136 break;
137 default:
138 llvm_unreachable("Unknown EF_MIPS_ARCH value");
139 }
140
141 switch (PlatformFlags & ELF::EF_MIPS_MACH) {
142 case ELF::EF_MIPS_MACH_NONE:
143 // No feature associated with this value.
144 break;
145 case ELF::EF_MIPS_MACH_OCTEON:
146 Features.AddFeature("cnmips");
147 break;
148 default:
149 llvm_unreachable("Unknown EF_MIPS_ARCH value");
150 }
151
152 if (PlatformFlags & ELF::EF_MIPS_ARCH_ASE_M16)
153 Features.AddFeature("mips16");
154 if (PlatformFlags & ELF::EF_MIPS_MICROMIPS)
155 Features.AddFeature("micromips");
156
157 return Features;
158 }
159
getARMFeatures() const160 SubtargetFeatures ELFObjectFileBase::getARMFeatures() const {
161 SubtargetFeatures Features;
162 ARMAttributeParser Attributes;
163 if (Error E = getBuildAttributes(Attributes)) {
164 consumeError(std::move(E));
165 return SubtargetFeatures();
166 }
167
168 // both ARMv7-M and R have to support thumb hardware div
169 bool isV7 = false;
170 std::optional<unsigned> Attr =
171 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch);
172 if (Attr)
173 isV7 = *Attr == ARMBuildAttrs::v7;
174
175 Attr = Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile);
176 if (Attr) {
177 switch (*Attr) {
178 case ARMBuildAttrs::ApplicationProfile:
179 Features.AddFeature("aclass");
180 break;
181 case ARMBuildAttrs::RealTimeProfile:
182 Features.AddFeature("rclass");
183 if (isV7)
184 Features.AddFeature("hwdiv");
185 break;
186 case ARMBuildAttrs::MicroControllerProfile:
187 Features.AddFeature("mclass");
188 if (isV7)
189 Features.AddFeature("hwdiv");
190 break;
191 }
192 }
193
194 Attr = Attributes.getAttributeValue(ARMBuildAttrs::THUMB_ISA_use);
195 if (Attr) {
196 switch (*Attr) {
197 default:
198 break;
199 case ARMBuildAttrs::Not_Allowed:
200 Features.AddFeature("thumb", false);
201 Features.AddFeature("thumb2", false);
202 break;
203 case ARMBuildAttrs::AllowThumb32:
204 Features.AddFeature("thumb2");
205 break;
206 }
207 }
208
209 Attr = Attributes.getAttributeValue(ARMBuildAttrs::FP_arch);
210 if (Attr) {
211 switch (*Attr) {
212 default:
213 break;
214 case ARMBuildAttrs::Not_Allowed:
215 Features.AddFeature("vfp2sp", false);
216 Features.AddFeature("vfp3d16sp", false);
217 Features.AddFeature("vfp4d16sp", false);
218 break;
219 case ARMBuildAttrs::AllowFPv2:
220 Features.AddFeature("vfp2");
221 break;
222 case ARMBuildAttrs::AllowFPv3A:
223 case ARMBuildAttrs::AllowFPv3B:
224 Features.AddFeature("vfp3");
225 break;
226 case ARMBuildAttrs::AllowFPv4A:
227 case ARMBuildAttrs::AllowFPv4B:
228 Features.AddFeature("vfp4");
229 break;
230 }
231 }
232
233 Attr = Attributes.getAttributeValue(ARMBuildAttrs::Advanced_SIMD_arch);
234 if (Attr) {
235 switch (*Attr) {
236 default:
237 break;
238 case ARMBuildAttrs::Not_Allowed:
239 Features.AddFeature("neon", false);
240 Features.AddFeature("fp16", false);
241 break;
242 case ARMBuildAttrs::AllowNeon:
243 Features.AddFeature("neon");
244 break;
245 case ARMBuildAttrs::AllowNeon2:
246 Features.AddFeature("neon");
247 Features.AddFeature("fp16");
248 break;
249 }
250 }
251
252 Attr = Attributes.getAttributeValue(ARMBuildAttrs::MVE_arch);
253 if (Attr) {
254 switch (*Attr) {
255 default:
256 break;
257 case ARMBuildAttrs::Not_Allowed:
258 Features.AddFeature("mve", false);
259 Features.AddFeature("mve.fp", false);
260 break;
261 case ARMBuildAttrs::AllowMVEInteger:
262 Features.AddFeature("mve.fp", false);
263 Features.AddFeature("mve");
264 break;
265 case ARMBuildAttrs::AllowMVEIntegerAndFloat:
266 Features.AddFeature("mve.fp");
267 break;
268 }
269 }
270
271 Attr = Attributes.getAttributeValue(ARMBuildAttrs::DIV_use);
272 if (Attr) {
273 switch (*Attr) {
274 default:
275 break;
276 case ARMBuildAttrs::DisallowDIV:
277 Features.AddFeature("hwdiv", false);
278 Features.AddFeature("hwdiv-arm", false);
279 break;
280 case ARMBuildAttrs::AllowDIVExt:
281 Features.AddFeature("hwdiv");
282 Features.AddFeature("hwdiv-arm");
283 break;
284 }
285 }
286
287 return Features;
288 }
289
getRISCVFeatures() const290 Expected<SubtargetFeatures> ELFObjectFileBase::getRISCVFeatures() const {
291 SubtargetFeatures Features;
292 unsigned PlatformFlags = getPlatformFlags();
293
294 if (PlatformFlags & ELF::EF_RISCV_RVC) {
295 Features.AddFeature("c");
296 }
297
298 RISCVAttributeParser Attributes;
299 if (Error E = getBuildAttributes(Attributes)) {
300 return std::move(E);
301 }
302
303 std::optional<StringRef> Attr =
304 Attributes.getAttributeString(RISCVAttrs::ARCH);
305 if (Attr) {
306 // Suppress version checking for experimental extensions to prevent erroring
307 // when getting any unknown version of experimental extension.
308 auto ParseResult = RISCVISAInfo::parseArchString(
309 *Attr, /*EnableExperimentalExtension=*/true,
310 /*ExperimentalExtensionVersionCheck=*/false,
311 /*IgnoreUnknown=*/true);
312 if (!ParseResult)
313 return ParseResult.takeError();
314 auto &ISAInfo = *ParseResult;
315
316 if (ISAInfo->getXLen() == 32)
317 Features.AddFeature("64bit", false);
318 else if (ISAInfo->getXLen() == 64)
319 Features.AddFeature("64bit");
320 else
321 llvm_unreachable("XLEN should be 32 or 64.");
322
323 Features.addFeaturesVector(ISAInfo->toFeatureVector());
324 }
325
326 return Features;
327 }
328
getLoongArchFeatures() const329 SubtargetFeatures ELFObjectFileBase::getLoongArchFeatures() const {
330 SubtargetFeatures Features;
331
332 switch (getPlatformFlags() & ELF::EF_LOONGARCH_ABI_MODIFIER_MASK) {
333 case ELF::EF_LOONGARCH_ABI_SOFT_FLOAT:
334 break;
335 case ELF::EF_LOONGARCH_ABI_DOUBLE_FLOAT:
336 Features.AddFeature("d");
337 // D implies F according to LoongArch ISA spec.
338 [[fallthrough]];
339 case ELF::EF_LOONGARCH_ABI_SINGLE_FLOAT:
340 Features.AddFeature("f");
341 break;
342 }
343
344 return Features;
345 }
346
getFeatures() const347 Expected<SubtargetFeatures> ELFObjectFileBase::getFeatures() const {
348 switch (getEMachine()) {
349 case ELF::EM_MIPS:
350 return getMIPSFeatures();
351 case ELF::EM_ARM:
352 return getARMFeatures();
353 case ELF::EM_RISCV:
354 return getRISCVFeatures();
355 case ELF::EM_LOONGARCH:
356 return getLoongArchFeatures();
357 default:
358 return SubtargetFeatures();
359 }
360 }
361
tryGetCPUName() const362 std::optional<StringRef> ELFObjectFileBase::tryGetCPUName() const {
363 switch (getEMachine()) {
364 case ELF::EM_AMDGPU:
365 return getAMDGPUCPUName();
366 case ELF::EM_PPC64:
367 return StringRef("future");
368 default:
369 return std::nullopt;
370 }
371 }
372
getAMDGPUCPUName() const373 StringRef ELFObjectFileBase::getAMDGPUCPUName() const {
374 assert(getEMachine() == ELF::EM_AMDGPU);
375 unsigned CPU = getPlatformFlags() & ELF::EF_AMDGPU_MACH;
376
377 switch (CPU) {
378 // Radeon HD 2000/3000 Series (R600).
379 case ELF::EF_AMDGPU_MACH_R600_R600:
380 return "r600";
381 case ELF::EF_AMDGPU_MACH_R600_R630:
382 return "r630";
383 case ELF::EF_AMDGPU_MACH_R600_RS880:
384 return "rs880";
385 case ELF::EF_AMDGPU_MACH_R600_RV670:
386 return "rv670";
387
388 // Radeon HD 4000 Series (R700).
389 case ELF::EF_AMDGPU_MACH_R600_RV710:
390 return "rv710";
391 case ELF::EF_AMDGPU_MACH_R600_RV730:
392 return "rv730";
393 case ELF::EF_AMDGPU_MACH_R600_RV770:
394 return "rv770";
395
396 // Radeon HD 5000 Series (Evergreen).
397 case ELF::EF_AMDGPU_MACH_R600_CEDAR:
398 return "cedar";
399 case ELF::EF_AMDGPU_MACH_R600_CYPRESS:
400 return "cypress";
401 case ELF::EF_AMDGPU_MACH_R600_JUNIPER:
402 return "juniper";
403 case ELF::EF_AMDGPU_MACH_R600_REDWOOD:
404 return "redwood";
405 case ELF::EF_AMDGPU_MACH_R600_SUMO:
406 return "sumo";
407
408 // Radeon HD 6000 Series (Northern Islands).
409 case ELF::EF_AMDGPU_MACH_R600_BARTS:
410 return "barts";
411 case ELF::EF_AMDGPU_MACH_R600_CAICOS:
412 return "caicos";
413 case ELF::EF_AMDGPU_MACH_R600_CAYMAN:
414 return "cayman";
415 case ELF::EF_AMDGPU_MACH_R600_TURKS:
416 return "turks";
417
418 // AMDGCN GFX6.
419 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX600:
420 return "gfx600";
421 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX601:
422 return "gfx601";
423 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX602:
424 return "gfx602";
425
426 // AMDGCN GFX7.
427 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX700:
428 return "gfx700";
429 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX701:
430 return "gfx701";
431 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX702:
432 return "gfx702";
433 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX703:
434 return "gfx703";
435 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX704:
436 return "gfx704";
437 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX705:
438 return "gfx705";
439
440 // AMDGCN GFX8.
441 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX801:
442 return "gfx801";
443 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX802:
444 return "gfx802";
445 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX803:
446 return "gfx803";
447 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX805:
448 return "gfx805";
449 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX810:
450 return "gfx810";
451
452 // AMDGCN GFX9.
453 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX900:
454 return "gfx900";
455 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX902:
456 return "gfx902";
457 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX904:
458 return "gfx904";
459 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX906:
460 return "gfx906";
461 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX908:
462 return "gfx908";
463 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX909:
464 return "gfx909";
465 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90A:
466 return "gfx90a";
467 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90C:
468 return "gfx90c";
469 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX940:
470 return "gfx940";
471
472 // AMDGCN GFX10.
473 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1010:
474 return "gfx1010";
475 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1011:
476 return "gfx1011";
477 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1012:
478 return "gfx1012";
479 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1013:
480 return "gfx1013";
481 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1030:
482 return "gfx1030";
483 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1031:
484 return "gfx1031";
485 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1032:
486 return "gfx1032";
487 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1033:
488 return "gfx1033";
489 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1034:
490 return "gfx1034";
491 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1035:
492 return "gfx1035";
493 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1036:
494 return "gfx1036";
495
496 // AMDGCN GFX11.
497 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1100:
498 return "gfx1100";
499 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1101:
500 return "gfx1101";
501 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1102:
502 return "gfx1102";
503 case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1103:
504 return "gfx1103";
505 default:
506 llvm_unreachable("Unknown EF_AMDGPU_MACH value");
507 }
508 }
509
510 // FIXME Encode from a tablegen description or target parser.
setARMSubArch(Triple & TheTriple) const511 void ELFObjectFileBase::setARMSubArch(Triple &TheTriple) const {
512 if (TheTriple.getSubArch() != Triple::NoSubArch)
513 return;
514
515 ARMAttributeParser Attributes;
516 if (Error E = getBuildAttributes(Attributes)) {
517 // TODO Propagate Error.
518 consumeError(std::move(E));
519 return;
520 }
521
522 std::string Triple;
523 // Default to ARM, but use the triple if it's been set.
524 if (TheTriple.isThumb())
525 Triple = "thumb";
526 else
527 Triple = "arm";
528
529 std::optional<unsigned> Attr =
530 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch);
531 if (Attr) {
532 switch (*Attr) {
533 case ARMBuildAttrs::v4:
534 Triple += "v4";
535 break;
536 case ARMBuildAttrs::v4T:
537 Triple += "v4t";
538 break;
539 case ARMBuildAttrs::v5T:
540 Triple += "v5t";
541 break;
542 case ARMBuildAttrs::v5TE:
543 Triple += "v5te";
544 break;
545 case ARMBuildAttrs::v5TEJ:
546 Triple += "v5tej";
547 break;
548 case ARMBuildAttrs::v6:
549 Triple += "v6";
550 break;
551 case ARMBuildAttrs::v6KZ:
552 Triple += "v6kz";
553 break;
554 case ARMBuildAttrs::v6T2:
555 Triple += "v6t2";
556 break;
557 case ARMBuildAttrs::v6K:
558 Triple += "v6k";
559 break;
560 case ARMBuildAttrs::v7: {
561 std::optional<unsigned> ArchProfileAttr =
562 Attributes.getAttributeValue(ARMBuildAttrs::CPU_arch_profile);
563 if (ArchProfileAttr &&
564 *ArchProfileAttr == ARMBuildAttrs::MicroControllerProfile)
565 Triple += "v7m";
566 else
567 Triple += "v7";
568 break;
569 }
570 case ARMBuildAttrs::v6_M:
571 Triple += "v6m";
572 break;
573 case ARMBuildAttrs::v6S_M:
574 Triple += "v6sm";
575 break;
576 case ARMBuildAttrs::v7E_M:
577 Triple += "v7em";
578 break;
579 case ARMBuildAttrs::v8_A:
580 Triple += "v8a";
581 break;
582 case ARMBuildAttrs::v8_R:
583 Triple += "v8r";
584 break;
585 case ARMBuildAttrs::v8_M_Base:
586 Triple += "v8m.base";
587 break;
588 case ARMBuildAttrs::v8_M_Main:
589 Triple += "v8m.main";
590 break;
591 case ARMBuildAttrs::v8_1_M_Main:
592 Triple += "v8.1m.main";
593 break;
594 case ARMBuildAttrs::v9_A:
595 Triple += "v9a";
596 break;
597 }
598 }
599 if (!isLittleEndian())
600 Triple += "eb";
601
602 TheTriple.setArchName(Triple);
603 }
604
605 std::vector<std::pair<std::optional<DataRefImpl>, uint64_t>>
getPltAddresses() const606 ELFObjectFileBase::getPltAddresses() const {
607 std::string Err;
608 const auto Triple = makeTriple();
609 const auto *T = TargetRegistry::lookupTarget(Triple.str(), Err);
610 if (!T)
611 return {};
612 uint64_t JumpSlotReloc = 0;
613 switch (Triple.getArch()) {
614 case Triple::x86:
615 JumpSlotReloc = ELF::R_386_JUMP_SLOT;
616 break;
617 case Triple::x86_64:
618 JumpSlotReloc = ELF::R_X86_64_JUMP_SLOT;
619 break;
620 case Triple::aarch64:
621 case Triple::aarch64_be:
622 JumpSlotReloc = ELF::R_AARCH64_JUMP_SLOT;
623 break;
624 default:
625 return {};
626 }
627 std::unique_ptr<const MCInstrInfo> MII(T->createMCInstrInfo());
628 std::unique_ptr<const MCInstrAnalysis> MIA(
629 T->createMCInstrAnalysis(MII.get()));
630 if (!MIA)
631 return {};
632 std::optional<SectionRef> Plt, RelaPlt, GotPlt;
633 for (const SectionRef &Section : sections()) {
634 Expected<StringRef> NameOrErr = Section.getName();
635 if (!NameOrErr) {
636 consumeError(NameOrErr.takeError());
637 continue;
638 }
639 StringRef Name = *NameOrErr;
640
641 if (Name == ".plt")
642 Plt = Section;
643 else if (Name == ".rela.plt" || Name == ".rel.plt")
644 RelaPlt = Section;
645 else if (Name == ".got.plt")
646 GotPlt = Section;
647 }
648 if (!Plt || !RelaPlt || !GotPlt)
649 return {};
650 Expected<StringRef> PltContents = Plt->getContents();
651 if (!PltContents) {
652 consumeError(PltContents.takeError());
653 return {};
654 }
655 auto PltEntries = MIA->findPltEntries(Plt->getAddress(),
656 arrayRefFromStringRef(*PltContents),
657 GotPlt->getAddress(), Triple);
658 // Build a map from GOT entry virtual address to PLT entry virtual address.
659 DenseMap<uint64_t, uint64_t> GotToPlt;
660 for (const auto &Entry : PltEntries)
661 GotToPlt.insert(std::make_pair(Entry.second, Entry.first));
662 // Find the relocations in the dynamic relocation table that point to
663 // locations in the GOT for which we know the corresponding PLT entry.
664 std::vector<std::pair<std::optional<DataRefImpl>, uint64_t>> Result;
665 for (const auto &Relocation : RelaPlt->relocations()) {
666 if (Relocation.getType() != JumpSlotReloc)
667 continue;
668 auto PltEntryIter = GotToPlt.find(Relocation.getOffset());
669 if (PltEntryIter != GotToPlt.end()) {
670 symbol_iterator Sym = Relocation.getSymbol();
671 if (Sym == symbol_end())
672 Result.emplace_back(std::nullopt, PltEntryIter->second);
673 else
674 Result.emplace_back(Sym->getRawDataRefImpl(), PltEntryIter->second);
675 }
676 }
677 return Result;
678 }
679
680 template <class ELFT>
readBBAddrMapImpl(const ELFFile<ELFT> & EF,std::optional<unsigned> TextSectionIndex)681 Expected<std::vector<BBAddrMap>> static readBBAddrMapImpl(
682 const ELFFile<ELFT> &EF, std::optional<unsigned> TextSectionIndex) {
683 using Elf_Shdr = typename ELFT::Shdr;
684 std::vector<BBAddrMap> BBAddrMaps;
685 const auto &Sections = cantFail(EF.sections());
686 for (const Elf_Shdr &Sec : Sections) {
687 if (Sec.sh_type != ELF::SHT_LLVM_BB_ADDR_MAP &&
688 Sec.sh_type != ELF::SHT_LLVM_BB_ADDR_MAP_V0)
689 continue;
690 if (TextSectionIndex) {
691 Expected<const Elf_Shdr *> TextSecOrErr = EF.getSection(Sec.sh_link);
692 if (!TextSecOrErr)
693 return createError("unable to get the linked-to section for " +
694 describe(EF, Sec) + ": " +
695 toString(TextSecOrErr.takeError()));
696 if (*TextSectionIndex != std::distance(Sections.begin(), *TextSecOrErr))
697 continue;
698 }
699 Expected<std::vector<BBAddrMap>> BBAddrMapOrErr = EF.decodeBBAddrMap(Sec);
700 if (!BBAddrMapOrErr)
701 return createError("unable to read " + describe(EF, Sec) + ": " +
702 toString(BBAddrMapOrErr.takeError()));
703 std::move(BBAddrMapOrErr->begin(), BBAddrMapOrErr->end(),
704 std::back_inserter(BBAddrMaps));
705 }
706 return BBAddrMaps;
707 }
708
709 template <class ELFT>
710 static Expected<std::vector<VersionEntry>>
readDynsymVersionsImpl(const ELFFile<ELFT> & EF,ELFObjectFileBase::elf_symbol_iterator_range Symbols)711 readDynsymVersionsImpl(const ELFFile<ELFT> &EF,
712 ELFObjectFileBase::elf_symbol_iterator_range Symbols) {
713 using Elf_Shdr = typename ELFT::Shdr;
714 const Elf_Shdr *VerSec = nullptr;
715 const Elf_Shdr *VerNeedSec = nullptr;
716 const Elf_Shdr *VerDefSec = nullptr;
717 // The user should ensure sections() can't fail here.
718 for (const Elf_Shdr &Sec : cantFail(EF.sections())) {
719 if (Sec.sh_type == ELF::SHT_GNU_versym)
720 VerSec = &Sec;
721 else if (Sec.sh_type == ELF::SHT_GNU_verdef)
722 VerDefSec = &Sec;
723 else if (Sec.sh_type == ELF::SHT_GNU_verneed)
724 VerNeedSec = &Sec;
725 }
726 if (!VerSec)
727 return std::vector<VersionEntry>();
728
729 Expected<SmallVector<std::optional<VersionEntry>, 0>> MapOrErr =
730 EF.loadVersionMap(VerNeedSec, VerDefSec);
731 if (!MapOrErr)
732 return MapOrErr.takeError();
733
734 std::vector<VersionEntry> Ret;
735 size_t I = 0;
736 for (const ELFSymbolRef &Sym : Symbols) {
737 ++I;
738 Expected<const typename ELFT::Versym *> VerEntryOrErr =
739 EF.template getEntry<typename ELFT::Versym>(*VerSec, I);
740 if (!VerEntryOrErr)
741 return createError("unable to read an entry with index " + Twine(I) +
742 " from " + describe(EF, *VerSec) + ": " +
743 toString(VerEntryOrErr.takeError()));
744
745 Expected<uint32_t> FlagsOrErr = Sym.getFlags();
746 if (!FlagsOrErr)
747 return createError("unable to read flags for symbol with index " +
748 Twine(I) + ": " + toString(FlagsOrErr.takeError()));
749
750 bool IsDefault;
751 Expected<StringRef> VerOrErr = EF.getSymbolVersionByIndex(
752 (*VerEntryOrErr)->vs_index, IsDefault, *MapOrErr,
753 (*FlagsOrErr) & SymbolRef::SF_Undefined);
754 if (!VerOrErr)
755 return createError("unable to get a version for entry " + Twine(I) +
756 " of " + describe(EF, *VerSec) + ": " +
757 toString(VerOrErr.takeError()));
758
759 Ret.push_back({(*VerOrErr).str(), IsDefault});
760 }
761
762 return Ret;
763 }
764
765 Expected<std::vector<VersionEntry>>
readDynsymVersions() const766 ELFObjectFileBase::readDynsymVersions() const {
767 elf_symbol_iterator_range Symbols = getDynamicSymbolIterators();
768 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(this))
769 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols);
770 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(this))
771 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols);
772 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(this))
773 return readDynsymVersionsImpl(Obj->getELFFile(), Symbols);
774 return readDynsymVersionsImpl(cast<ELF64BEObjectFile>(this)->getELFFile(),
775 Symbols);
776 }
777
readBBAddrMap(std::optional<unsigned> TextSectionIndex) const778 Expected<std::vector<BBAddrMap>> ELFObjectFileBase::readBBAddrMap(
779 std::optional<unsigned> TextSectionIndex) const {
780 if (const auto *Obj = dyn_cast<ELF32LEObjectFile>(this))
781 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
782 if (const auto *Obj = dyn_cast<ELF64LEObjectFile>(this))
783 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
784 if (const auto *Obj = dyn_cast<ELF32BEObjectFile>(this))
785 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
786 if (const auto *Obj = cast<ELF64BEObjectFile>(this))
787 return readBBAddrMapImpl(Obj->getELFFile(), TextSectionIndex);
788 else
789 llvm_unreachable("Unsupported binary format");
790 }
791