diff options
| -rw-r--r-- | lld/ELF/Target.cpp | 53 | ||||
| -rw-r--r-- | lld/test/ELF/mips-64-rels.s | 46 |
2 files changed, 85 insertions, 14 deletions
diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp index 1cfe1e3019a..ccb33132c69 100644 --- a/lld/ELF/Target.cpp +++ b/lld/ELF/Target.cpp @@ -1244,6 +1244,9 @@ template <class ELFT> MipsTargetInfo<ELFT>::MipsTargetInfo() { template <class ELFT> RelExpr MipsTargetInfo<ELFT>::getRelExpr(uint32_t Type, const SymbolBody &S) const { + if (ELFT::Is64Bits) + // See comment in the calculateMips64RelChain. + Type &= 0xff; switch (Type) { default: return R_ABS; @@ -1443,14 +1446,44 @@ uint64_t MipsTargetInfo<ELFT>::getImplicitAddend(const uint8_t *Buf, } } +static std::pair<uint32_t, uint64_t> calculateMips64RelChain(uint32_t Type, + uint64_t Val) { + // MIPS N64 ABI packs multiple relocations into the single relocation + // record. In general, all up to three relocations can have arbitrary + // types. In fact, Clang and GCC uses only a few combinations. For now, + // we support two of them. That is allow to pass at least all LLVM + // test suite cases. + // <any relocation> / R_MIPS_SUB / R_MIPS_HI16 | R_MIPS_LO16 + // <any relocation> / R_MIPS_64 / R_MIPS_NONE + // The first relocation is a 'real' relocation which is calculated + // using the corresponding symbol's value. The second and the third + // relocations used to modify result of the first one: extend it to + // 64-bit, extract high or low part etc. For details, see part 2.9 Relocation + // at the https://dmz-portal.mips.com/mw/images/8/82/007-4658-001.pdf + uint32_t Type2 = (Type >> 8) & 0xff; + uint32_t Type3 = (Type >> 16) & 0xff; + if (Type2 == R_MIPS_NONE && Type3 == R_MIPS_NONE) + return std::make_pair(Type, Val); + if (Type2 == R_MIPS_64 && Type3 == R_MIPS_NONE) + return std::make_pair(Type2, Val); + if (Type2 == R_MIPS_SUB && (Type3 == R_MIPS_HI16 || Type3 == R_MIPS_LO16)) + return std::make_pair(Type3, -Val); + error("unsupported relocations combination " + Twine(Type)); + return std::make_pair(Type & 0xff, Val); +} + template <class ELFT> void MipsTargetInfo<ELFT>::relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const { const endianness E = ELFT::TargetEndianness; // Thread pointer and DRP offsets from the start of TLS data area. // https://www.linux-mips.org/wiki/NPTL - const uint32_t TPOffset = 0x7000; - const uint32_t DTPOffset = 0x8000; + if (Type == R_MIPS_TLS_DTPREL_HI16 || Type == R_MIPS_TLS_DTPREL_LO16) + Val -= 0x8000; + else if (Type == R_MIPS_TLS_TPREL_HI16 || Type == R_MIPS_TLS_TPREL_LO16) + Val -= 0x7000; + if (ELFT::Is64Bits) + std::tie(Type, Val) = calculateMips64RelChain(Type, Val); switch (Type) { case R_MIPS_32: case R_MIPS_GPREL32: @@ -1472,10 +1505,14 @@ void MipsTargetInfo<ELFT>::relocateOne(uint8_t *Loc, uint32_t Type, case R_MIPS_GOT_OFST: case R_MIPS_LO16: case R_MIPS_PCLO16: + case R_MIPS_TLS_DTPREL_LO16: + case R_MIPS_TLS_TPREL_LO16: writeMipsLo16<E>(Loc, Val); break; case R_MIPS_HI16: case R_MIPS_PCHI16: + case R_MIPS_TLS_DTPREL_HI16: + case R_MIPS_TLS_TPREL_HI16: writeMipsHi16<E>(Loc, Val); break; case R_MIPS_JALR: @@ -1496,18 +1533,6 @@ void MipsTargetInfo<ELFT>::relocateOne(uint8_t *Loc, uint32_t Type, case R_MIPS_PC32: applyMipsPcReloc<E, 32, 0>(Loc, Type, Val); break; - case R_MIPS_TLS_DTPREL_HI16: - writeMipsHi16<E>(Loc, Val - DTPOffset); - break; - case R_MIPS_TLS_DTPREL_LO16: - writeMipsLo16<E>(Loc, Val - DTPOffset); - break; - case R_MIPS_TLS_TPREL_HI16: - writeMipsHi16<E>(Loc, Val - TPOffset); - break; - case R_MIPS_TLS_TPREL_LO16: - writeMipsLo16<E>(Loc, Val - TPOffset); - break; default: fatal("unrecognized reloc " + Twine(Type)); } diff --git a/lld/test/ELF/mips-64-rels.s b/lld/test/ELF/mips-64-rels.s new file mode 100644 index 00000000000..7126afc1e59 --- /dev/null +++ b/lld/test/ELF/mips-64-rels.s @@ -0,0 +1,46 @@ +# Check handling multiple MIPS N64 ABI relocations packed +# into the single relocation record. + +# RUN: llvm-mc -filetype=obj -triple=mips64-unknown-linux %s -o %t.o +# RUN: ld.lld %t.o -o %t.exe +# RUN: llvm-objdump -d -s -t %t.exe | FileCheck %s +# RUN: llvm-readobj -r %t.exe | FileCheck -check-prefix=REL %s + +# REQUIRES: mips + +# CHECK: __start: +# CHECK-NEXT: 20000: 3c 1c 00 01 lui $gp, 1 +# ^-- 0x20000 - 0x37ff0 +# ^-- 0 - 0xfffffffffffe8010 +# ^-- %hi(0x17ff0) +# CHECK: loc: +# CHECK-NEXT: 20004: 67 9c 7f f0 daddiu $gp, $gp, 32752 +# ^-- 0x20000 - 0x37ff0 +# ^-- 0 - 0xfffffffffffe8010 +# ^-- %lo(0x17ff0) + +# CHECK: Contents of section .rodata: +# CHECK-NEXT: 10190 ffffffff fffe8014 +# ^-- 0x20004 - 0x37ff0 = 0xfffffffffffe8014 + +# CHECK: 0000000000020004 .text 00000000 loc +# CHECK: 0000000000037ff0 .got 00000000 .hidden _gp +# CHECK: 0000000000020000 .text 00000000 __start + +# REL: Relocations [ +# REL-NEXT: ] + + .text + .global __start +__start: + lui $gp,%hi(%neg(%gp_rel(__start))) # R_MIPS_GPREL16 + # R_MIPS_SUB + # R_MIPS_HI16 +loc: + daddiu $gp,$gp,%lo(%neg(%gp_rel(__start))) # R_MIPS_GPREL16 + # R_MIPS_SUB + # R_MIPS_LO16 + + .section .rodata,"a",@progbits + .gpdword(loc) # R_MIPS_GPREL32 + # R_MIPS_64 |
