| 1 | //===- SystemZ.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 "OutputSections.h" |
| 10 | #include "Symbols.h" |
| 11 | #include "SyntheticSections.h" |
| 12 | #include "Target.h" |
| 13 | #include "llvm/BinaryFormat/ELF.h" |
| 14 | #include "llvm/Support/Endian.h" |
| 15 | |
| 16 | using namespace llvm; |
| 17 | using namespace llvm::support::endian; |
| 18 | using namespace llvm::ELF; |
| 19 | using namespace lld; |
| 20 | using namespace lld::elf; |
| 21 | |
| 22 | namespace { |
| 23 | class SystemZ : public TargetInfo { |
| 24 | public: |
| 25 | SystemZ(Ctx &); |
| 26 | int getTlsGdRelaxSkip(RelType type) const override; |
| 27 | RelExpr getRelExpr(RelType type, const Symbol &s, |
| 28 | const uint8_t *loc) const override; |
| 29 | RelType getDynRel(RelType type) const override; |
| 30 | void writeGotHeader(uint8_t *buf) const override; |
| 31 | void writeGotPlt(uint8_t *buf, const Symbol &s) const override; |
| 32 | void writeIgotPlt(uint8_t *buf, const Symbol &s) const override; |
| 33 | void writePltHeader(uint8_t *buf) const override; |
| 34 | void addPltHeaderSymbols(InputSection &isd) const override; |
| 35 | void writePlt(uint8_t *buf, const Symbol &sym, |
| 36 | uint64_t pltEntryAddr) const override; |
| 37 | RelExpr adjustTlsExpr(RelType type, RelExpr expr) const override; |
| 38 | RelExpr adjustGotPcExpr(RelType type, int64_t addend, |
| 39 | const uint8_t *loc) const override; |
| 40 | bool relaxOnce(int pass) const override; |
| 41 | void relocate(uint8_t *loc, const Relocation &rel, |
| 42 | uint64_t val) const override; |
| 43 | int64_t getImplicitAddend(const uint8_t *buf, RelType type) const override; |
| 44 | |
| 45 | private: |
| 46 | void relaxGot(uint8_t *loc, const Relocation &rel, uint64_t val) const; |
| 47 | void relaxTlsGdToIe(uint8_t *loc, const Relocation &rel, uint64_t val) const; |
| 48 | void relaxTlsGdToLe(uint8_t *loc, const Relocation &rel, uint64_t val) const; |
| 49 | void relaxTlsLdToLe(uint8_t *loc, const Relocation &rel, uint64_t val) const; |
| 50 | }; |
| 51 | } // namespace |
| 52 | |
| 53 | SystemZ::SystemZ(Ctx &ctx) : TargetInfo(ctx) { |
| 54 | copyRel = R_390_COPY; |
| 55 | gotRel = R_390_GLOB_DAT; |
| 56 | pltRel = R_390_JMP_SLOT; |
| 57 | relativeRel = R_390_RELATIVE; |
| 58 | iRelativeRel = R_390_IRELATIVE; |
| 59 | symbolicRel = R_390_64; |
| 60 | tlsGotRel = R_390_TLS_TPOFF; |
| 61 | tlsModuleIndexRel = R_390_TLS_DTPMOD; |
| 62 | tlsOffsetRel = R_390_TLS_DTPOFF; |
| 63 | gotHeaderEntriesNum = 3; |
| 64 | gotPltHeaderEntriesNum = 0; |
| 65 | gotEntrySize = 8; |
| 66 | pltHeaderSize = 32; |
| 67 | pltEntrySize = 32; |
| 68 | ipltEntrySize = 32; |
| 69 | |
| 70 | // This "trap instruction" is used to fill gaps between sections. |
| 71 | // On SystemZ, the behavior of the GNU ld is to fill those gaps |
| 72 | // with nop instructions instead - and unfortunately the default |
| 73 | // glibc crt object files (used to) rely on that behavior since |
| 74 | // they use an alignment on the .init section fragments that causes |
| 75 | // gaps which must be filled with nops as they are being executed. |
| 76 | // Therefore, we provide a nop instruction as "trapInstr" here. |
| 77 | trapInstr = {0x07, 0x07, 0x07, 0x07}; |
| 78 | |
| 79 | defaultImageBase = 0x1000000; |
| 80 | } |
| 81 | |
| 82 | RelExpr SystemZ::getRelExpr(RelType type, const Symbol &s, |
| 83 | const uint8_t *loc) const { |
| 84 | switch (type) { |
| 85 | case R_390_NONE: |
| 86 | return R_NONE; |
| 87 | // Relocations targeting the symbol value. |
| 88 | case R_390_8: |
| 89 | case R_390_12: |
| 90 | case R_390_16: |
| 91 | case R_390_20: |
| 92 | case R_390_32: |
| 93 | case R_390_64: |
| 94 | return R_ABS; |
| 95 | case R_390_PC16: |
| 96 | case R_390_PC32: |
| 97 | case R_390_PC64: |
| 98 | case R_390_PC12DBL: |
| 99 | case R_390_PC16DBL: |
| 100 | case R_390_PC24DBL: |
| 101 | case R_390_PC32DBL: |
| 102 | return R_PC; |
| 103 | case R_390_GOTOFF16: |
| 104 | case R_390_GOTOFF: // a.k.a. R_390_GOTOFF32 |
| 105 | case R_390_GOTOFF64: |
| 106 | return R_GOTREL; |
| 107 | // Relocations targeting the PLT associated with the symbol. |
| 108 | case R_390_PLT32: |
| 109 | case R_390_PLT64: |
| 110 | case R_390_PLT12DBL: |
| 111 | case R_390_PLT16DBL: |
| 112 | case R_390_PLT24DBL: |
| 113 | case R_390_PLT32DBL: |
| 114 | return R_PLT_PC; |
| 115 | case R_390_PLTOFF16: |
| 116 | case R_390_PLTOFF32: |
| 117 | case R_390_PLTOFF64: |
| 118 | return R_PLT_GOTREL; |
| 119 | // Relocations targeting the GOT entry associated with the symbol. |
| 120 | case R_390_GOTENT: |
| 121 | return R_GOT_PC; |
| 122 | case R_390_GOT12: |
| 123 | case R_390_GOT16: |
| 124 | case R_390_GOT20: |
| 125 | case R_390_GOT32: |
| 126 | case R_390_GOT64: |
| 127 | return R_GOT_OFF; |
| 128 | // Relocations targeting the GOTPLT entry associated with the symbol. |
| 129 | case R_390_GOTPLTENT: |
| 130 | return R_GOTPLT_PC; |
| 131 | case R_390_GOTPLT12: |
| 132 | case R_390_GOTPLT16: |
| 133 | case R_390_GOTPLT20: |
| 134 | case R_390_GOTPLT32: |
| 135 | case R_390_GOTPLT64: |
| 136 | return R_GOTPLT_GOTREL; |
| 137 | // Relocations targeting _GLOBAL_OFFSET_TABLE_. |
| 138 | case R_390_GOTPC: |
| 139 | case R_390_GOTPCDBL: |
| 140 | return R_GOTONLY_PC; |
| 141 | // TLS-related relocations. |
| 142 | case R_390_TLS_LOAD: |
| 143 | return R_NONE; |
| 144 | case R_390_TLS_GDCALL: |
| 145 | return R_TLSGD_PC; |
| 146 | case R_390_TLS_LDCALL: |
| 147 | return R_TLSLD_PC; |
| 148 | case R_390_TLS_GD32: |
| 149 | case R_390_TLS_GD64: |
| 150 | return R_TLSGD_GOT; |
| 151 | case R_390_TLS_LDM32: |
| 152 | case R_390_TLS_LDM64: |
| 153 | return R_TLSLD_GOT; |
| 154 | case R_390_TLS_LDO32: |
| 155 | case R_390_TLS_LDO64: |
| 156 | return R_DTPREL; |
| 157 | case R_390_TLS_LE32: |
| 158 | case R_390_TLS_LE64: |
| 159 | return R_TPREL; |
| 160 | case R_390_TLS_IE32: |
| 161 | case R_390_TLS_IE64: |
| 162 | return R_GOT; |
| 163 | case R_390_TLS_GOTIE12: |
| 164 | case R_390_TLS_GOTIE20: |
| 165 | case R_390_TLS_GOTIE32: |
| 166 | case R_390_TLS_GOTIE64: |
| 167 | return R_GOT_OFF; |
| 168 | case R_390_TLS_IEENT: |
| 169 | return R_GOT_PC; |
| 170 | |
| 171 | default: |
| 172 | Err(ctx) << getErrorLoc(ctx, loc) << "unknown relocation (" << type.v |
| 173 | << ") against symbol " << &s; |
| 174 | return R_NONE; |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | void SystemZ::(uint8_t *buf) const { |
| 179 | // _GLOBAL_OFFSET_TABLE_[0] holds the value of _DYNAMIC. |
| 180 | // _GLOBAL_OFFSET_TABLE_[1] and [2] are reserved. |
| 181 | write64be(P: buf, V: ctx.mainPart->dynamic->getVA()); |
| 182 | } |
| 183 | |
| 184 | void SystemZ::writeGotPlt(uint8_t *buf, const Symbol &s) const { |
| 185 | write64be(P: buf, V: s.getPltVA(ctx) + 14); |
| 186 | } |
| 187 | |
| 188 | void SystemZ::writeIgotPlt(uint8_t *buf, const Symbol &s) const { |
| 189 | if (ctx.arg.writeAddends) |
| 190 | write64be(P: buf, V: s.getVA(ctx)); |
| 191 | } |
| 192 | |
| 193 | void SystemZ::(uint8_t *buf) const { |
| 194 | const uint8_t pltData[] = { |
| 195 | 0xe3, 0x10, 0xf0, 0x38, 0x00, 0x24, // stg %r1,56(%r15) |
| 196 | 0xc0, 0x10, 0x00, 0x00, 0x00, 0x00, // larl %r1,_GLOBAL_OFFSET_TABLE_ |
| 197 | 0xd2, 0x07, 0xf0, 0x30, 0x10, 0x08, // mvc 48(8,%r15),8(%r1) |
| 198 | 0xe3, 0x10, 0x10, 0x10, 0x00, 0x04, // lg %r1,16(%r1) |
| 199 | 0x07, 0xf1, // br %r1 |
| 200 | 0x07, 0x00, // nopr |
| 201 | 0x07, 0x00, // nopr |
| 202 | 0x07, 0x00, // nopr |
| 203 | }; |
| 204 | memcpy(dest: buf, src: pltData, n: sizeof(pltData)); |
| 205 | uint64_t got = ctx.in.got->getVA(); |
| 206 | uint64_t plt = ctx.in.plt->getVA(); |
| 207 | write32be(P: buf + 8, V: (got - plt - 6) >> 1); |
| 208 | } |
| 209 | |
| 210 | void SystemZ::(InputSection &isec) const { |
| 211 | // The PLT header needs a reference to _GLOBAL_OFFSET_TABLE_, so we |
| 212 | // must ensure the .got section is created even if otherwise unused. |
| 213 | ctx.in.got->hasGotOffRel.store(i: true, m: std::memory_order_relaxed); |
| 214 | } |
| 215 | |
| 216 | void SystemZ::writePlt(uint8_t *buf, const Symbol &sym, |
| 217 | uint64_t pltEntryAddr) const { |
| 218 | const uint8_t inst[] = { |
| 219 | 0xc0, 0x10, 0x00, 0x00, 0x00, 0x00, // larl %r1,<.got.plt slot> |
| 220 | 0xe3, 0x10, 0x10, 0x00, 0x00, 0x04, // lg %r1,0(%r1) |
| 221 | 0x07, 0xf1, // br %r1 |
| 222 | 0x0d, 0x10, // basr %r1,%r0 |
| 223 | 0xe3, 0x10, 0x10, 0x0c, 0x00, 0x14, // lgf %r1,12(%r1) |
| 224 | 0xc0, 0xf4, 0x00, 0x00, 0x00, 0x00, // jg <plt header> |
| 225 | 0x00, 0x00, 0x00, 0x00, // <relocation offset> |
| 226 | }; |
| 227 | memcpy(dest: buf, src: inst, n: sizeof(inst)); |
| 228 | |
| 229 | write32be(P: buf + 2, V: (sym.getGotPltVA(ctx) - pltEntryAddr) >> 1); |
| 230 | write32be(P: buf + 24, V: (ctx.in.plt->getVA() - pltEntryAddr - 22) >> 1); |
| 231 | write32be(P: buf + 28, V: ctx.in.relaPlt->entsize * sym.getPltIdx(ctx)); |
| 232 | } |
| 233 | |
| 234 | int64_t SystemZ::getImplicitAddend(const uint8_t *buf, RelType type) const { |
| 235 | switch (type) { |
| 236 | case R_390_8: |
| 237 | return SignExtend64<8>(x: *buf); |
| 238 | case R_390_16: |
| 239 | case R_390_PC16: |
| 240 | return SignExtend64<16>(x: read16be(P: buf)); |
| 241 | case R_390_PC16DBL: |
| 242 | return SignExtend64<16>(x: read16be(P: buf)) << 1; |
| 243 | case R_390_32: |
| 244 | case R_390_PC32: |
| 245 | return SignExtend64<32>(x: read32be(P: buf)); |
| 246 | case R_390_PC32DBL: |
| 247 | return SignExtend64<32>(x: read32be(P: buf)) << 1; |
| 248 | case R_390_64: |
| 249 | case R_390_PC64: |
| 250 | case R_390_TLS_DTPMOD: |
| 251 | case R_390_TLS_DTPOFF: |
| 252 | case R_390_TLS_TPOFF: |
| 253 | case R_390_GLOB_DAT: |
| 254 | case R_390_RELATIVE: |
| 255 | case R_390_IRELATIVE: |
| 256 | return read64be(P: buf); |
| 257 | case R_390_COPY: |
| 258 | case R_390_JMP_SLOT: |
| 259 | case R_390_NONE: |
| 260 | // These relocations are defined as not having an implicit addend. |
| 261 | return 0; |
| 262 | default: |
| 263 | InternalErr(ctx, buf) << "cannot read addend for relocation " << type; |
| 264 | return 0; |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | RelType SystemZ::getDynRel(RelType type) const { |
| 269 | if (type == R_390_64 || type == R_390_PC64) |
| 270 | return type; |
| 271 | return R_390_NONE; |
| 272 | } |
| 273 | |
| 274 | RelExpr SystemZ::adjustTlsExpr(RelType type, RelExpr expr) const { |
| 275 | if (expr == R_RELAX_TLS_GD_TO_IE) |
| 276 | return R_RELAX_TLS_GD_TO_IE_GOT_OFF; |
| 277 | return expr; |
| 278 | } |
| 279 | |
| 280 | int SystemZ::getTlsGdRelaxSkip(RelType type) const { |
| 281 | // A __tls_get_offset call instruction is marked with 2 relocations: |
| 282 | // |
| 283 | // R_390_TLS_GDCALL / R_390_TLS_LDCALL: marker relocation |
| 284 | // R_390_PLT32DBL: __tls_get_offset |
| 285 | // |
| 286 | // After the relaxation we no longer call __tls_get_offset and should skip |
| 287 | // both relocations to not create a false dependence on __tls_get_offset |
| 288 | // being defined. |
| 289 | // |
| 290 | // Note that this mechanism only works correctly if the R_390_TLS_[GL]DCALL |
| 291 | // is seen immediately *before* the R_390_PLT32DBL. Unfortunately, current |
| 292 | // compilers on the platform will typically generate the inverse sequence. |
| 293 | // To fix this, we sort relocations by offset in RelocationScanner::scan; |
| 294 | // this ensures the correct sequence as the R_390_TLS_[GL]DCALL applies to |
| 295 | // the first byte of the brasl instruction, while the R_390_PLT32DBL applies |
| 296 | // to its third byte (the relative displacement). |
| 297 | |
| 298 | if (type == R_390_TLS_GDCALL || type == R_390_TLS_LDCALL) |
| 299 | return 2; |
| 300 | return 1; |
| 301 | } |
| 302 | |
| 303 | void SystemZ::relaxTlsGdToIe(uint8_t *loc, const Relocation &rel, |
| 304 | uint64_t val) const { |
| 305 | // The general-dynamic code sequence for a global `x`: |
| 306 | // |
| 307 | // Instruction Relocation Symbol |
| 308 | // ear %rX,%a0 |
| 309 | // sllg %rX,%rX,32 |
| 310 | // ear %rX,%a1 |
| 311 | // larl %r12,_GLOBAL_OFFSET_TABLE_ R_390_GOTPCDBL _GLOBAL_OFFSET_TABLE_ |
| 312 | // lgrl %r2,.LC0 R_390_PC32DBL .LC0 |
| 313 | // brasl %r14,__tls_get_offset@plt R_390_TLS_GDCALL x |
| 314 | // :tls_gdcall:x R_390_PLT32DBL __tls_get_offset |
| 315 | // la %r2,0(%r2,%rX) |
| 316 | // |
| 317 | // .LC0: |
| 318 | // .quad x@TLSGD R_390_TLS_GD64 x |
| 319 | // |
| 320 | // Relaxing to initial-exec entails: |
| 321 | // 1) Replacing the call by a load from the GOT. |
| 322 | // 2) Replacing the relocation on the constant LC0 by R_390_TLS_GOTIE64. |
| 323 | |
| 324 | switch (rel.type) { |
| 325 | case R_390_TLS_GDCALL: |
| 326 | // brasl %r14,__tls_get_offset@plt -> lg %r2,0(%r2,%r12) |
| 327 | write16be(P: loc, V: 0xe322); |
| 328 | write32be(P: loc + 2, V: 0xc0000004); |
| 329 | break; |
| 330 | case R_390_TLS_GD64: |
| 331 | relocateNoSym(loc, type: R_390_TLS_GOTIE64, val); |
| 332 | break; |
| 333 | default: |
| 334 | llvm_unreachable("unsupported relocation for TLS GD to IE relaxation" ); |
| 335 | } |
| 336 | } |
| 337 | |
| 338 | void SystemZ::relaxTlsGdToLe(uint8_t *loc, const Relocation &rel, |
| 339 | uint64_t val) const { |
| 340 | // The general-dynamic code sequence for a global `x`: |
| 341 | // |
| 342 | // Instruction Relocation Symbol |
| 343 | // ear %rX,%a0 |
| 344 | // sllg %rX,%rX,32 |
| 345 | // ear %rX,%a1 |
| 346 | // larl %r12,_GLOBAL_OFFSET_TABLE_ R_390_GOTPCDBL _GLOBAL_OFFSET_TABLE_ |
| 347 | // lgrl %r2,.LC0 R_390_PC32DBL .LC0 |
| 348 | // brasl %r14,__tls_get_offset@plt R_390_TLS_GDCALL x |
| 349 | // :tls_gdcall:x R_390_PLT32DBL __tls_get_offset |
| 350 | // la %r2,0(%r2,%rX) |
| 351 | // |
| 352 | // .LC0: |
| 353 | // .quad x@tlsgd R_390_TLS_GD64 x |
| 354 | // |
| 355 | // Relaxing to local-exec entails: |
| 356 | // 1) Replacing the call by a nop. |
| 357 | // 2) Replacing the relocation on the constant LC0 by R_390_TLS_LE64. |
| 358 | |
| 359 | switch (rel.type) { |
| 360 | case R_390_TLS_GDCALL: |
| 361 | // brasl %r14,__tls_get_offset@plt -> brcl 0,. |
| 362 | write16be(P: loc, V: 0xc004); |
| 363 | write32be(P: loc + 2, V: 0x00000000); |
| 364 | break; |
| 365 | case R_390_TLS_GD64: |
| 366 | relocateNoSym(loc, type: R_390_TLS_LE64, val); |
| 367 | break; |
| 368 | default: |
| 369 | llvm_unreachable("unsupported relocation for TLS GD to LE relaxation" ); |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | void SystemZ::relaxTlsLdToLe(uint8_t *loc, const Relocation &rel, |
| 374 | uint64_t val) const { |
| 375 | // The local-dynamic code sequence for a global `x`: |
| 376 | // |
| 377 | // Instruction Relocation Symbol |
| 378 | // ear %rX,%a0 |
| 379 | // sllg %rX,%rX,32 |
| 380 | // ear %rX,%a1 |
| 381 | // larl %r12,_GLOBAL_OFFSET_TABLE_ R_390_GOTPCDBL _GLOBAL_OFFSET_TABLE_ |
| 382 | // lgrl %r2,.LC0 R_390_PC32DBL .LC0 |
| 383 | // brasl %r14,__tls_get_offset@plt R_390_TLS_LDCALL <sym> |
| 384 | // :tls_ldcall:<sym> R_390_PLT32DBL __tls_get_offset |
| 385 | // la %r2,0(%r2,%rX) |
| 386 | // lgrl %rY,.LC1 R_390_PC32DBL .LC1 |
| 387 | // la %r2,0(%r2,%rY) |
| 388 | // |
| 389 | // .LC0: |
| 390 | // .quad <sym>@tlsldm R_390_TLS_LDM64 <sym> |
| 391 | // .LC1: |
| 392 | // .quad x@dtpoff R_390_TLS_LDO64 x |
| 393 | // |
| 394 | // Relaxing to local-exec entails: |
| 395 | // 1) Replacing the call by a nop. |
| 396 | // 2) Replacing the constant LC0 by 0 (i.e. ignoring the relocation). |
| 397 | // 3) Replacing the relocation on the constant LC1 by R_390_TLS_LE64. |
| 398 | |
| 399 | switch (rel.type) { |
| 400 | case R_390_TLS_LDCALL: |
| 401 | // brasl %r14,__tls_get_offset@plt -> brcl 0,. |
| 402 | write16be(P: loc, V: 0xc004); |
| 403 | write32be(P: loc + 2, V: 0x00000000); |
| 404 | break; |
| 405 | case R_390_TLS_LDM64: |
| 406 | break; |
| 407 | case R_390_TLS_LDO64: |
| 408 | relocateNoSym(loc, type: R_390_TLS_LE64, val); |
| 409 | break; |
| 410 | default: |
| 411 | llvm_unreachable("unsupported relocation for TLS LD to LE relaxation" ); |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | RelExpr SystemZ::adjustGotPcExpr(RelType type, int64_t addend, |
| 416 | const uint8_t *loc) const { |
| 417 | // Only R_390_GOTENT with addend 2 can be relaxed. |
| 418 | if (!ctx.arg.relax || addend != 2 || type != R_390_GOTENT) |
| 419 | return R_GOT_PC; |
| 420 | const uint16_t op = read16be(P: loc - 2); |
| 421 | |
| 422 | // lgrl rx,sym@GOTENT -> larl rx, sym |
| 423 | // This relaxation is legal if "sym" binds locally (which was already |
| 424 | // verified by our caller) and is in-range and properly aligned for a |
| 425 | // LARL instruction. We cannot verify the latter constraint here, so |
| 426 | // we assume it is true and revert the decision later on in relaxOnce |
| 427 | // if necessary. |
| 428 | if ((op & 0xff0f) == 0xc408) |
| 429 | return R_RELAX_GOT_PC; |
| 430 | |
| 431 | return R_GOT_PC; |
| 432 | } |
| 433 | |
| 434 | bool SystemZ::relaxOnce(int pass) const { |
| 435 | // If we decided in adjustGotPcExpr to relax a R_390_GOTENT, |
| 436 | // we need to validate the target symbol is in-range and aligned. |
| 437 | SmallVector<InputSection *, 0> storage; |
| 438 | bool changed = false; |
| 439 | for (OutputSection *osec : ctx.outputSections) { |
| 440 | if (!(osec->flags & SHF_EXECINSTR)) |
| 441 | continue; |
| 442 | for (InputSection *sec : getInputSections(os: *osec, storage)) { |
| 443 | for (Relocation &rel : sec->relocs()) { |
| 444 | if (rel.expr != R_RELAX_GOT_PC) |
| 445 | continue; |
| 446 | |
| 447 | uint64_t v = sec->getRelocTargetVA( |
| 448 | ctx, r: rel, p: sec->getOutputSection()->addr + rel.offset); |
| 449 | if (isInt<33>(x: v) && !(v & 1)) |
| 450 | continue; |
| 451 | if (rel.sym->auxIdx == 0) { |
| 452 | rel.sym->allocateAux(ctx); |
| 453 | addGotEntry(ctx, sym&: *rel.sym); |
| 454 | changed = true; |
| 455 | } |
| 456 | rel.expr = R_GOT_PC; |
| 457 | } |
| 458 | } |
| 459 | } |
| 460 | return changed; |
| 461 | } |
| 462 | |
| 463 | void SystemZ::relaxGot(uint8_t *loc, const Relocation &rel, |
| 464 | uint64_t val) const { |
| 465 | assert(isInt<33>(val) && |
| 466 | "R_390_GOTENT should not have been relaxed if it overflows" ); |
| 467 | assert(!(val & 1) && |
| 468 | "R_390_GOTENT should not have been relaxed if it is misaligned" ); |
| 469 | const uint16_t op = read16be(P: loc - 2); |
| 470 | |
| 471 | // lgrl rx,sym@GOTENT -> larl rx, sym |
| 472 | if ((op & 0xff0f) == 0xc408) { |
| 473 | write16be(P: loc - 2, V: 0xc000 | (op & 0x00f0)); |
| 474 | write32be(P: loc, V: val >> 1); |
| 475 | } |
| 476 | } |
| 477 | |
| 478 | void SystemZ::relocate(uint8_t *loc, const Relocation &rel, |
| 479 | uint64_t val) const { |
| 480 | switch (rel.expr) { |
| 481 | case R_RELAX_GOT_PC: |
| 482 | return relaxGot(loc, rel, val); |
| 483 | case R_RELAX_TLS_GD_TO_IE_GOT_OFF: |
| 484 | return relaxTlsGdToIe(loc, rel, val); |
| 485 | case R_RELAX_TLS_GD_TO_LE: |
| 486 | return relaxTlsGdToLe(loc, rel, val); |
| 487 | case R_RELAX_TLS_LD_TO_LE: |
| 488 | return relaxTlsLdToLe(loc, rel, val); |
| 489 | default: |
| 490 | break; |
| 491 | } |
| 492 | switch (rel.type) { |
| 493 | case R_390_8: |
| 494 | checkIntUInt(ctx, loc, v: val, n: 8, rel); |
| 495 | *loc = val; |
| 496 | break; |
| 497 | case R_390_12: |
| 498 | case R_390_GOT12: |
| 499 | case R_390_GOTPLT12: |
| 500 | case R_390_TLS_GOTIE12: |
| 501 | checkUInt(ctx, loc, v: val, n: 12, rel); |
| 502 | write16be(P: loc, V: (read16be(P: loc) & 0xF000) | val); |
| 503 | break; |
| 504 | case R_390_PC12DBL: |
| 505 | case R_390_PLT12DBL: |
| 506 | checkInt(ctx, loc, v: val, n: 13, rel); |
| 507 | checkAlignment(ctx, loc, v: val, n: 2, rel); |
| 508 | write16be(P: loc, V: (read16be(P: loc) & 0xF000) | ((val >> 1) & 0x0FFF)); |
| 509 | break; |
| 510 | case R_390_16: |
| 511 | case R_390_GOT16: |
| 512 | case R_390_GOTPLT16: |
| 513 | case R_390_GOTOFF16: |
| 514 | case R_390_PLTOFF16: |
| 515 | checkIntUInt(ctx, loc, v: val, n: 16, rel); |
| 516 | write16be(P: loc, V: val); |
| 517 | break; |
| 518 | case R_390_PC16: |
| 519 | checkInt(ctx, loc, v: val, n: 16, rel); |
| 520 | write16be(P: loc, V: val); |
| 521 | break; |
| 522 | case R_390_PC16DBL: |
| 523 | case R_390_PLT16DBL: |
| 524 | checkInt(ctx, loc, v: val, n: 17, rel); |
| 525 | checkAlignment(ctx, loc, v: val, n: 2, rel); |
| 526 | write16be(P: loc, V: val >> 1); |
| 527 | break; |
| 528 | case R_390_20: |
| 529 | case R_390_GOT20: |
| 530 | case R_390_GOTPLT20: |
| 531 | case R_390_TLS_GOTIE20: |
| 532 | checkInt(ctx, loc, v: val, n: 20, rel); |
| 533 | write32be(P: loc, V: (read32be(P: loc) & 0xF00000FF) | ((val & 0xFFF) << 16) | |
| 534 | ((val & 0xFF000) >> 4)); |
| 535 | break; |
| 536 | case R_390_PC24DBL: |
| 537 | case R_390_PLT24DBL: |
| 538 | checkInt(ctx, loc, v: val, n: 25, rel); |
| 539 | checkAlignment(ctx, loc, v: val, n: 2, rel); |
| 540 | loc[0] = val >> 17; |
| 541 | loc[1] = val >> 9; |
| 542 | loc[2] = val >> 1; |
| 543 | break; |
| 544 | case R_390_32: |
| 545 | case R_390_GOT32: |
| 546 | case R_390_GOTPLT32: |
| 547 | case R_390_GOTOFF: |
| 548 | case R_390_PLTOFF32: |
| 549 | case R_390_TLS_IE32: |
| 550 | case R_390_TLS_GOTIE32: |
| 551 | case R_390_TLS_GD32: |
| 552 | case R_390_TLS_LDM32: |
| 553 | case R_390_TLS_LDO32: |
| 554 | case R_390_TLS_LE32: |
| 555 | checkIntUInt(ctx, loc, v: val, n: 32, rel); |
| 556 | write32be(P: loc, V: val); |
| 557 | break; |
| 558 | case R_390_PC32: |
| 559 | case R_390_PLT32: |
| 560 | checkInt(ctx, loc, v: val, n: 32, rel); |
| 561 | write32be(P: loc, V: val); |
| 562 | break; |
| 563 | case R_390_PC32DBL: |
| 564 | case R_390_PLT32DBL: |
| 565 | case R_390_GOTPCDBL: |
| 566 | case R_390_GOTENT: |
| 567 | case R_390_GOTPLTENT: |
| 568 | case R_390_TLS_IEENT: |
| 569 | checkInt(ctx, loc, v: val, n: 33, rel); |
| 570 | checkAlignment(ctx, loc, v: val, n: 2, rel); |
| 571 | write32be(P: loc, V: val >> 1); |
| 572 | break; |
| 573 | case R_390_64: |
| 574 | case R_390_PC64: |
| 575 | case R_390_PLT64: |
| 576 | case R_390_GOT64: |
| 577 | case R_390_GOTPLT64: |
| 578 | case R_390_GOTOFF64: |
| 579 | case R_390_PLTOFF64: |
| 580 | case R_390_GOTPC: |
| 581 | case R_390_TLS_IE64: |
| 582 | case R_390_TLS_GOTIE64: |
| 583 | case R_390_TLS_GD64: |
| 584 | case R_390_TLS_LDM64: |
| 585 | case R_390_TLS_LDO64: |
| 586 | case R_390_TLS_LE64: |
| 587 | case R_390_TLS_DTPMOD: |
| 588 | case R_390_TLS_DTPOFF: |
| 589 | case R_390_TLS_TPOFF: |
| 590 | write64be(P: loc, V: val); |
| 591 | break; |
| 592 | case R_390_TLS_LOAD: |
| 593 | case R_390_TLS_GDCALL: |
| 594 | case R_390_TLS_LDCALL: |
| 595 | break; |
| 596 | default: |
| 597 | llvm_unreachable("unknown relocation" ); |
| 598 | } |
| 599 | } |
| 600 | |
| 601 | void elf::setSystemZTargetInfo(Ctx &ctx) { ctx.target.reset(p: new SystemZ(ctx)); } |
| 602 | |