1//===- PPC.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 "InputFiles.h"
10#include "OutputSections.h"
11#include "RelocScan.h"
12#include "Symbols.h"
13#include "SyntheticSections.h"
14#include "Target.h"
15#include "Thunks.h"
16
17using namespace llvm;
18using namespace llvm::support::endian;
19using namespace llvm::ELF;
20using namespace lld;
21using namespace lld::elf;
22
23// Undefine the macro predefined by GCC powerpc32.
24#undef PPC
25
26namespace {
27class PPC final : public TargetInfo {
28public:
29 PPC(Ctx &);
30 RelExpr getRelExpr(RelType type, const Symbol &s,
31 const uint8_t *loc) const override;
32 RelType getDynRel(RelType type) const override;
33 int64_t getImplicitAddend(const uint8_t *buf, RelType type) const override;
34 void writeGotHeader(uint8_t *buf) const override;
35 void writePltHeader(uint8_t *buf) const override {
36 llvm_unreachable("should call writePPC32GlinkSection() instead");
37 }
38 void writePlt(uint8_t *buf, const Symbol &sym,
39 uint64_t pltEntryAddr) const override {
40 llvm_unreachable("should call writePPC32GlinkSection() instead");
41 }
42 void writeIplt(uint8_t *buf, const Symbol &sym,
43 uint64_t pltEntryAddr) const override;
44 void writeGotPlt(uint8_t *buf, const Symbol &s) const override;
45 template <class ELFT, class RelTy>
46 void scanSectionImpl(InputSectionBase &, Relocs<RelTy>);
47 void scanSection(InputSectionBase &) override;
48 bool needsThunk(RelExpr expr, RelType relocType, const InputFile *file,
49 uint64_t branchAddr, const Symbol &s,
50 int64_t a) const override;
51 uint32_t getThunkSectionSpacing() const override;
52 bool inBranchRange(RelType type, uint64_t src, uint64_t dst) const override;
53 void relocate(uint8_t *loc, const Relocation &rel,
54 uint64_t val) const override;
55private:
56 void relaxTlsGdToIe(uint8_t *loc, const Relocation &rel, uint64_t val) const;
57 void relaxTlsGdToLe(uint8_t *loc, const Relocation &rel, uint64_t val) const;
58 void relaxTlsLdToLe(uint8_t *loc, const Relocation &rel, uint64_t val) const;
59 void relaxTlsIeToLe(uint8_t *loc, const Relocation &rel, uint64_t val) const;
60};
61} // namespace
62
63static uint16_t lo(uint32_t v) { return v; }
64static uint16_t ha(uint32_t v) { return (v + 0x8000) >> 16; }
65
66static uint32_t readFromHalf16(Ctx &ctx, const uint8_t *loc) {
67 return read32(ctx, p: ctx.arg.isLE ? loc : loc - 2);
68}
69
70static void writeFromHalf16(Ctx &ctx, uint8_t *loc, uint32_t insn) {
71 write32(ctx, p: ctx.arg.isLE ? loc : loc - 2, v: insn);
72}
73
74void elf::writePPC32GlinkSection(Ctx &ctx, uint8_t *buf, size_t numEntries) {
75 // Create canonical PLT entries for non-PIE code. Compilers don't generate
76 // non-GOT-non-PLT relocations referencing external functions for -fpie/-fPIE.
77 uint32_t glink = ctx.in.plt->getVA(); // VA of .glink
78 if (!ctx.arg.isPic) {
79 for (const Symbol *sym :
80 cast<PPC32GlinkSection>(Val&: *ctx.in.plt).canonical_plts) {
81 writePPC32PltCallStub(ctx, buf, gotPltVA: sym->getGotPltVA(ctx), file: nullptr, addend: 0);
82 buf += 16;
83 glink += 16;
84 }
85 }
86
87 // On PPC Secure PLT ABI, bl foo@plt jumps to a call stub, which loads an
88 // absolute address from a specific .plt slot (usually called .got.plt on
89 // other targets) and jumps there.
90 //
91 // a) With immediate binding (BIND_NOW), the .plt entry is resolved at load
92 // time. The .glink section is not used.
93 // b) With lazy binding, the .plt entry points to a `b PLTresolve`
94 // instruction in .glink, filled in by PPC::writeGotPlt().
95
96 // Write N `b PLTresolve` first.
97 for (size_t i = 0; i != numEntries; ++i)
98 write32(ctx, p: buf + 4 * i, v: 0x48000000 | 4 * (numEntries - i));
99 buf += 4 * numEntries;
100
101 // Then write PLTresolve(), which has two forms: PIC and non-PIC. PLTresolve()
102 // computes the PLT index (by computing the distance from the landing b to
103 // itself) and calls _dl_runtime_resolve() (in glibc).
104 uint32_t got = ctx.in.got->getVA();
105 const uint8_t *end = buf + 64;
106 if (ctx.arg.isPic) {
107 uint32_t afterBcl = 4 * ctx.in.plt->getNumEntries() + 12;
108 uint32_t gotBcl = got + 4 - (glink + afterBcl);
109 write32(ctx, p: buf + 0,
110 v: 0x3d6b0000 | ha(v: afterBcl)); // addis r11,r11,1f-glink@ha
111 write32(ctx, p: buf + 4, v: 0x7c0802a6); // mflr r0
112 write32(ctx, p: buf + 8, v: 0x429f0005); // bcl 20,30,.+4
113 write32(ctx, p: buf + 12,
114 v: 0x396b0000 | lo(v: afterBcl)); // 1: addi r11,r11,1b-glink@l
115 write32(ctx, p: buf + 16, v: 0x7d8802a6); // mflr r12
116 write32(ctx, p: buf + 20, v: 0x7c0803a6); // mtlr r0
117 write32(ctx, p: buf + 24, v: 0x7d6c5850); // sub r11,r11,r12
118 write32(ctx, p: buf + 28, v: 0x3d8c0000 | ha(v: gotBcl)); // addis 12,12,GOT+4-1b@ha
119 if (ha(v: gotBcl) == ha(v: gotBcl + 4)) {
120 write32(ctx, p: buf + 32,
121 v: 0x800c0000 | lo(v: gotBcl)); // lwz r0,r12,GOT+4-1b@l(r12)
122 write32(ctx, p: buf + 36,
123 v: 0x818c0000 | lo(v: gotBcl + 4)); // lwz r12,r12,GOT+8-1b@l(r12)
124 } else {
125 write32(ctx, p: buf + 32,
126 v: 0x840c0000 | lo(v: gotBcl)); // lwzu r0,r12,GOT+4-1b@l(r12)
127 write32(ctx, p: buf + 36, v: 0x818c0000 | 4); // lwz r12,r12,4(r12)
128 }
129 write32(ctx, p: buf + 40, v: 0x7c0903a6); // mtctr 0
130 write32(ctx, p: buf + 44, v: 0x7c0b5a14); // add r0,11,11
131 write32(ctx, p: buf + 48, v: 0x7d605a14); // add r11,0,11
132 write32(ctx, p: buf + 52, v: 0x4e800420); // bctr
133 buf += 56;
134 } else {
135 write32(ctx, p: buf + 0, v: 0x3d800000 | ha(v: got + 4)); // lis r12,GOT+4@ha
136 write32(ctx, p: buf + 4, v: 0x3d6b0000 | ha(v: -glink)); // addis r11,r11,-glink@ha
137 if (ha(v: got + 4) == ha(v: got + 8))
138 write32(ctx, p: buf + 8, v: 0x800c0000 | lo(v: got + 4)); // lwz r0,GOT+4@l(r12)
139 else
140 write32(ctx, p: buf + 8, v: 0x840c0000 | lo(v: got + 4)); // lwzu r0,GOT+4@l(r12)
141 write32(ctx, p: buf + 12, v: 0x396b0000 | lo(v: -glink)); // addi r11,r11,-glink@l
142 write32(ctx, p: buf + 16, v: 0x7c0903a6); // mtctr r0
143 write32(ctx, p: buf + 20, v: 0x7c0b5a14); // add r0,r11,r11
144 if (ha(v: got + 4) == ha(v: got + 8))
145 write32(ctx, p: buf + 24, v: 0x818c0000 | lo(v: got + 8)); // lwz r12,GOT+8@l(r12)
146 else
147 write32(ctx, p: buf + 24, v: 0x818c0000 | 4); // lwz r12,4(r12)
148 write32(ctx, p: buf + 28, v: 0x7d605a14); // add r11,r0,r11
149 write32(ctx, p: buf + 32, v: 0x4e800420); // bctr
150 buf += 36;
151 }
152
153 // Pad with nop. They should not be executed.
154 for (; buf < end; buf += 4)
155 write32(ctx, p: buf, v: 0x60000000);
156}
157
158PPC::PPC(Ctx &ctx) : TargetInfo(ctx) {
159 copyRel = R_PPC_COPY;
160 gotRel = R_PPC_GLOB_DAT;
161 pltRel = R_PPC_JMP_SLOT;
162 relativeRel = R_PPC_RELATIVE;
163 iRelativeRel = R_PPC_IRELATIVE;
164 symbolicRel = R_PPC_ADDR32;
165 gotHeaderEntriesNum = 3;
166 gotPltHeaderEntriesNum = 0;
167 pltHeaderSize = 0;
168 pltEntrySize = 4;
169 ipltEntrySize = 16;
170
171 needsThunks = true;
172
173 tlsModuleIndexRel = R_PPC_DTPMOD32;
174 tlsOffsetRel = R_PPC_DTPREL32;
175 tlsGotRel = R_PPC_TPREL32;
176
177 defaultMaxPageSize = 65536;
178 defaultImageBase = 0x10000000;
179
180 write32(ctx, p: trapInstr.data(), v: 0x7fe00008);
181}
182
183void PPC::writeIplt(uint8_t *buf, const Symbol &sym,
184 uint64_t /*pltEntryAddr*/) const {
185 // In -pie or -shared mode, assume r30 points to .got2+0x8000, and use a
186 // .got2.plt_pic32. thunk.
187 writePPC32PltCallStub(ctx, buf, gotPltVA: sym.getGotPltVA(ctx), file: sym.file, addend: 0x8000);
188}
189
190void PPC::writeGotHeader(uint8_t *buf) const {
191 // _GLOBAL_OFFSET_TABLE_[0] = _DYNAMIC
192 // glibc stores _dl_runtime_resolve in _GLOBAL_OFFSET_TABLE_[1],
193 // link_map in _GLOBAL_OFFSET_TABLE_[2].
194 write32(ctx, p: buf, v: ctx.mainPart->dynamic->getVA());
195}
196
197void PPC::writeGotPlt(uint8_t *buf, const Symbol &s) const {
198 // Address of the symbol resolver stub in .glink .
199 write32(ctx, p: buf,
200 v: ctx.in.plt->getVA() + ctx.in.plt->headerSize + 4 * s.getPltIdx(ctx));
201}
202
203bool PPC::needsThunk(RelExpr expr, RelType type, const InputFile *file,
204 uint64_t branchAddr, const Symbol &s, int64_t a) const {
205 if (type != R_PPC_LOCAL24PC && type != R_PPC_REL24 && type != R_PPC_PLTREL24)
206 return false;
207 if (s.isInPlt(ctx))
208 return true;
209 if (s.isUndefWeak())
210 return false;
211 return !PPC::inBranchRange(type, src: branchAddr, dst: s.getVA(ctx, addend: a));
212}
213
214uint32_t PPC::getThunkSectionSpacing() const { return 0x2000000; }
215
216bool PPC::inBranchRange(RelType type, uint64_t src, uint64_t dst) const {
217 uint64_t offset = dst - src;
218 if (type == R_PPC_LOCAL24PC || type == R_PPC_REL24 || type == R_PPC_PLTREL24)
219 return isInt<26>(x: offset);
220 llvm_unreachable("unsupported relocation type used in branch");
221}
222
223// Only needed to support relocations used by relocateNonAlloc and
224// preprocessRelocs.
225RelExpr PPC::getRelExpr(RelType type, const Symbol &s,
226 const uint8_t *loc) const {
227 switch (type) {
228 case R_PPC_NONE:
229 return R_NONE;
230 case R_PPC_ADDR32:
231 return R_ABS;
232 case R_PPC_DTPREL32:
233 return R_DTPREL;
234 case R_PPC_REL32:
235 return R_PC;
236 default:
237 Err(ctx) << getErrorLoc(ctx, loc) << "unknown relocation (" << type.v
238 << ") against symbol " << &s;
239 return R_NONE;
240 }
241}
242
243RelType PPC::getDynRel(RelType type) const {
244 if (type == R_PPC_ADDR32)
245 return type;
246 return R_PPC_NONE;
247}
248
249int64_t PPC::getImplicitAddend(const uint8_t *buf, RelType type) const {
250 switch (type) {
251 case R_PPC_NONE:
252 case R_PPC_GLOB_DAT:
253 case R_PPC_JMP_SLOT:
254 return 0;
255 case R_PPC_ADDR32:
256 case R_PPC_REL32:
257 case R_PPC_RELATIVE:
258 case R_PPC_IRELATIVE:
259 case R_PPC_DTPMOD32:
260 case R_PPC_DTPREL32:
261 case R_PPC_TPREL32:
262 return SignExtend64<32>(x: read32(ctx, p: buf));
263 default:
264 InternalErr(ctx, buf) << "cannot read addend for relocation " << type;
265 return 0;
266 }
267}
268
269template <class ELFT, class RelTy>
270void PPC::scanSectionImpl(InputSectionBase &sec, Relocs<RelTy> rels) {
271 RelocScan rs(ctx, &sec);
272 sec.relocations.reserve(N: rels.size());
273 for (auto it = rels.begin(); it != rels.end(); ++it) {
274 const RelTy &rel = *it;
275 uint32_t symIdx = rel.getSymbol(false);
276 Symbol &sym = sec.getFile<ELFT>()->getSymbol(symIdx);
277 uint64_t offset = rel.r_offset;
278 RelType type = rel.getType(false);
279 if (sym.isUndefined() && symIdx != 0 &&
280 rs.maybeReportUndefined(sym&: cast<Undefined>(Val&: sym), offset))
281 continue;
282 int64_t addend = rs.getAddend<ELFT>(rel, type);
283 RelExpr expr;
284 // Relocation types that only need a RelExpr set `expr` and break out of
285 // the switch to reach rs.process(). Types that need special handling
286 // (fast-path helpers, TLS) call a handler and use `continue`.
287 switch (type) {
288 case R_PPC_NONE:
289 continue;
290 // Absolute relocations:
291 case R_PPC_ADDR16_HA:
292 case R_PPC_ADDR16_HI:
293 case R_PPC_ADDR16_LO:
294 case R_PPC_ADDR24:
295 case R_PPC_ADDR32:
296 expr = R_ABS;
297 break;
298
299 // PC-relative relocations:
300 case R_PPC_REL14:
301 case R_PPC_REL32:
302 case R_PPC_REL16_LO:
303 case R_PPC_REL16_HI:
304 case R_PPC_REL16_HA:
305 rs.processR_PC(type, offset, addend, sym);
306 continue;
307
308 // GOT-generating relocation:
309 case R_PPC_GOT16:
310 expr = R_GOT_OFF;
311 break;
312
313 // PLT-generating relocations:
314 case R_PPC_LOCAL24PC:
315 case R_PPC_REL24:
316 rs.processR_PLT_PC(type, offset, addend, sym);
317 continue;
318 case R_PPC_PLTREL24:
319 ctx.in.got->hasGotOffRel.store(i: true, m: std::memory_order_relaxed);
320 if (LLVM_UNLIKELY(sym.isGnuIFunc())) {
321 rs.process(expr: RE_PPC32_PLTREL, type, offset, sym, addend);
322 } else if (sym.isPreemptible) {
323 sym.setFlags(NEEDS_PLT);
324 sec.addReloc(r: {.expr: RE_PPC32_PLTREL, .type: type, .offset: offset, .addend: addend, .sym: &sym});
325 } else {
326 // The 0x8000 bit of r_addend selects call stub type; mask it for direct
327 // calls.
328 addend &= ~0x8000;
329 rs.processAux(expr: R_PC, type, offset, sym, addend);
330 }
331 continue;
332
333 // TLS relocations:
334
335 // TLS LE:
336 case R_PPC_TPREL16:
337 case R_PPC_TPREL16_HA:
338 case R_PPC_TPREL16_LO:
339 case R_PPC_TPREL16_HI:
340 if (rs.checkTlsLe(offset, sym, type))
341 continue;
342 expr = R_TPREL;
343 break;
344
345 // TLS IE:
346 case R_PPC_GOT_TPREL16:
347 rs.handleTlsIe(ieExpr: R_GOT_OFF, type, offset, addend, sym);
348 continue;
349 case R_PPC_TLS:
350 if (!ctx.arg.shared && !sym.isPreemptible)
351 sec.addReloc(r: {.expr: R_TPREL, .type: type, .offset: offset, .addend: addend, .sym: &sym});
352 continue;
353
354 // TLS GD:
355 case R_PPC_GOT_TLSGD16:
356 rs.handleTlsGd(sharedExpr: R_TLSGD_GOT, ieExpr: R_GOT_OFF, leExpr: R_TPREL, type, offset, addend,
357 sym);
358 continue;
359 case R_PPC_TLSGD:
360 case R_PPC_TLSLD:
361 if (!ctx.arg.shared) {
362 sec.addReloc(r: {.expr: sym.isPreemptible ? R_GOT_OFF : R_TPREL, .type: type, .offset: offset,
363 .addend: addend, .sym: &sym});
364 ++it; // Skip REL24
365 }
366 continue;
367
368 // TLS LD:
369 case R_PPC_GOT_TLSLD16:
370 rs.handleTlsLd(sharedExpr: R_TLSLD_GOT, type, offset, addend, sym);
371 continue;
372 case R_PPC_DTPREL16:
373 case R_PPC_DTPREL16_HA:
374 case R_PPC_DTPREL16_HI:
375 case R_PPC_DTPREL16_LO:
376 case R_PPC_DTPREL32:
377 sec.addReloc(r: {.expr: R_DTPREL, .type: type, .offset: offset, .addend: addend, .sym: &sym});
378 continue;
379
380 default:
381 Err(ctx) << getErrorLoc(ctx, loc: sec.content().data() + offset)
382 << "unknown relocation (" << type.v << ") against symbol "
383 << &sym;
384 continue;
385 }
386 rs.process(expr, type, offset, sym, addend);
387 }
388}
389
390void PPC::scanSection(InputSectionBase &sec) {
391 if (ctx.arg.isLE)
392 elf::scanSection1<PPC, ELF32LE>(target&: *this, sec);
393 else
394 elf::scanSection1<PPC, ELF32BE>(target&: *this, sec);
395}
396
397static std::pair<RelType, uint64_t> fromDTPREL(RelType type, uint64_t val) {
398 uint64_t dtpBiasedVal = val - 0x8000;
399 switch (type) {
400 case R_PPC_DTPREL16:
401 return {R_PPC64_ADDR16, dtpBiasedVal};
402 case R_PPC_DTPREL16_HA:
403 return {R_PPC_ADDR16_HA, dtpBiasedVal};
404 case R_PPC_DTPREL16_HI:
405 return {R_PPC_ADDR16_HI, dtpBiasedVal};
406 case R_PPC_DTPREL16_LO:
407 return {R_PPC_ADDR16_LO, dtpBiasedVal};
408 case R_PPC_DTPREL32:
409 return {R_PPC_ADDR32, dtpBiasedVal};
410 default:
411 return {type, val};
412 }
413}
414
415void PPC::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
416 RelType newType;
417 std::tie(args&: newType, args&: val) = fromDTPREL(type: rel.type, val);
418 switch (newType) {
419 case R_PPC_ADDR16:
420 checkIntUInt(ctx, loc, v: val, n: 16, rel);
421 write16(ctx, p: loc, v: val);
422 break;
423 case R_PPC_GOT16:
424 case R_PPC_TPREL16:
425 checkInt(ctx, loc, v: val, n: 16, rel);
426 write16(ctx, p: loc, v: val);
427 break;
428 case R_PPC_GOT_TLSGD16:
429 if (rel.expr == R_TPREL)
430 relaxTlsGdToLe(loc, rel, val);
431 else if (rel.expr == R_GOT_OFF)
432 relaxTlsGdToIe(loc, rel, val);
433 else {
434 checkInt(ctx, loc, v: val, n: 16, rel);
435 write16(ctx, p: loc, v: val);
436 }
437 break;
438 case R_PPC_GOT_TLSLD16:
439 if (rel.expr == R_TPREL)
440 relaxTlsLdToLe(loc, rel, val);
441 else {
442 checkInt(ctx, loc, v: val, n: 16, rel);
443 write16(ctx, p: loc, v: val);
444 }
445 break;
446 case R_PPC_GOT_TPREL16:
447 if (rel.expr == R_TPREL)
448 relaxTlsIeToLe(loc, rel, val);
449 else {
450 checkInt(ctx, loc, v: val, n: 16, rel);
451 write16(ctx, p: loc, v: val);
452 }
453 break;
454 case R_PPC_ADDR16_HA:
455 case R_PPC_DTPREL16_HA:
456 case R_PPC_GOT_TLSGD16_HA:
457 case R_PPC_GOT_TLSLD16_HA:
458 case R_PPC_GOT_TPREL16_HA:
459 case R_PPC_REL16_HA:
460 case R_PPC_TPREL16_HA:
461 write16(ctx, p: loc, v: ha(v: val));
462 break;
463 case R_PPC_ADDR16_HI:
464 case R_PPC_DTPREL16_HI:
465 case R_PPC_GOT_TLSGD16_HI:
466 case R_PPC_GOT_TLSLD16_HI:
467 case R_PPC_GOT_TPREL16_HI:
468 case R_PPC_REL16_HI:
469 case R_PPC_TPREL16_HI:
470 write16(ctx, p: loc, v: val >> 16);
471 break;
472 case R_PPC_ADDR16_LO:
473 case R_PPC_DTPREL16_LO:
474 case R_PPC_GOT_TLSGD16_LO:
475 case R_PPC_GOT_TLSLD16_LO:
476 case R_PPC_GOT_TPREL16_LO:
477 case R_PPC_REL16_LO:
478 case R_PPC_TPREL16_LO:
479 write16(ctx, p: loc, v: val);
480 break;
481 case R_PPC_ADDR32:
482 case R_PPC_REL32:
483 write32(ctx, p: loc, v: val);
484 break;
485 case R_PPC_REL14: {
486 uint32_t mask = 0x0000FFFC;
487 checkInt(ctx, loc, v: val, n: 16, rel);
488 checkAlignment(ctx, loc, v: val, n: 4, rel);
489 write32(ctx, p: loc, v: (read32(ctx, p: loc) & ~mask) | (val & mask));
490 break;
491 }
492 case R_PPC_ADDR24:
493 case R_PPC_REL24:
494 case R_PPC_LOCAL24PC:
495 case R_PPC_PLTREL24: {
496 uint32_t mask = 0x03FFFFFC;
497 checkInt(ctx, loc, v: val, n: 26, rel);
498 checkAlignment(ctx, loc, v: val, n: 4, rel);
499 write32(ctx, p: loc, v: (read32(ctx, p: loc) & ~mask) | (val & mask));
500 break;
501 }
502 case R_PPC_TLSGD:
503 if (rel.expr == R_TPREL)
504 relaxTlsGdToLe(loc, rel, val);
505 else if (rel.expr == R_GOT_OFF)
506 relaxTlsGdToIe(loc, rel, val);
507 break;
508 case R_PPC_TLSLD:
509 if (rel.expr == R_TPREL)
510 relaxTlsLdToLe(loc, rel, val);
511 break;
512 case R_PPC_TLS:
513 if (rel.expr == R_TPREL)
514 relaxTlsIeToLe(loc, rel, val);
515 break;
516 default:
517 llvm_unreachable("unknown relocation");
518 }
519}
520
521void PPC::relaxTlsGdToIe(uint8_t *loc, const Relocation &rel,
522 uint64_t val) const {
523 switch (rel.type) {
524 case R_PPC_GOT_TLSGD16: {
525 // addi rT, rA, x@got@tlsgd --> lwz rT, x@got@tprel(rA)
526 uint32_t insn = readFromHalf16(ctx, loc);
527 writeFromHalf16(ctx, loc, insn: 0x80000000 | (insn & 0x03ff0000));
528 relocateNoSym(loc, type: R_PPC_GOT_TPREL16, val);
529 break;
530 }
531 case R_PPC_TLSGD:
532 // bl __tls_get_addr(x@tldgd) --> add r3, r3, r2
533 write32(ctx, p: loc, v: 0x7c631214);
534 break;
535 default:
536 llvm_unreachable("unsupported relocation for TLS GD to IE relaxation");
537 }
538}
539
540void PPC::relaxTlsGdToLe(uint8_t *loc, const Relocation &rel,
541 uint64_t val) const {
542 switch (rel.type) {
543 case R_PPC_GOT_TLSGD16:
544 // addi r3, r31, x@got@tlsgd --> addis r3, r2, x@tprel@ha
545 writeFromHalf16(ctx, loc, insn: 0x3c620000 | ha(v: val));
546 break;
547 case R_PPC_TLSGD:
548 // bl __tls_get_addr(x@tldgd) --> add r3, r3, x@tprel@l
549 write32(ctx, p: loc, v: 0x38630000 | lo(v: val));
550 break;
551 default:
552 llvm_unreachable("unsupported relocation for TLS GD to LE relaxation");
553 }
554}
555
556void PPC::relaxTlsLdToLe(uint8_t *loc, const Relocation &rel,
557 uint64_t val) const {
558 switch (rel.type) {
559 case R_PPC_GOT_TLSLD16:
560 // addi r3, rA, x@got@tlsgd --> addis r3, r2, 0
561 writeFromHalf16(ctx, loc, insn: 0x3c620000);
562 break;
563 case R_PPC_TLSLD:
564 // r3+x@dtprel computes r3+x-0x8000, while we want it to compute r3+x@tprel
565 // = r3+x-0x7000, so add 4096 to r3.
566 // bl __tls_get_addr(x@tlsld) --> addi r3, r3, 4096
567 write32(ctx, p: loc, v: 0x38631000);
568 break;
569 default:
570 llvm_unreachable("unsupported relocation for TLS LD to LE relaxation");
571 }
572}
573
574void PPC::relaxTlsIeToLe(uint8_t *loc, const Relocation &rel,
575 uint64_t val) const {
576 switch (rel.type) {
577 case R_PPC_GOT_TPREL16: {
578 // lwz rT, x@got@tprel(rA) --> addis rT, r2, x@tprel@ha
579 uint32_t rt = readFromHalf16(ctx, loc) & 0x03e00000;
580 writeFromHalf16(ctx, loc, insn: 0x3c020000 | rt | ha(v: val));
581 break;
582 }
583 case R_PPC_TLS: {
584 uint32_t insn = read32(ctx, p: loc);
585 if (insn >> 26 != 31)
586 ErrAlways(ctx) << "unrecognized instruction for IE to LE R_PPC_TLS";
587 // addi rT, rT, x@tls --> addi rT, rT, x@tprel@l
588 unsigned secondaryOp = (read32(ctx, p: loc) & 0x000007fe) >> 1;
589 uint32_t dFormOp = getPPCDFormOp(secondaryOp);
590 if (dFormOp == 0) { // Expecting a DS-Form instruction.
591 dFormOp = getPPCDSFormOp(secondaryOp);
592 if (dFormOp == 0)
593 ErrAlways(ctx) << "unrecognized instruction for IE to LE R_PPC_TLS";
594 }
595 write32(ctx, p: loc, v: (dFormOp | (insn & 0x03ff0000) | lo(v: val)));
596 break;
597 }
598 default:
599 llvm_unreachable("unsupported relocation for TLS IE to LE relaxation");
600 }
601}
602
603void elf::setPPCTargetInfo(Ctx &ctx) { ctx.target.reset(p: new PPC(ctx)); }
604