diff options
| -rw-r--r-- | lld/ELF/Relocations.cpp | 60 |
1 files changed, 34 insertions, 26 deletions
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp index c041399bb27..b3e293d839c 100644 --- a/lld/ELF/Relocations.cpp +++ b/lld/ELF/Relocations.cpp @@ -80,24 +80,25 @@ static std::string getLocation(InputSectionBase &S, const SymbolBody &Sym, return Msg + S.getObjMsg<ELFT>(Off); } -static bool isPreemptible(const SymbolBody &Body, RelType Type) { - // In case of MIPS GP-relative relocations always resolve to a definition - // in a regular input file, ignoring the one-definition rule. So we, - // for example, should not attempt to create a dynamic relocation even - // if the target symbol is preemptible. There are two two MIPS GP-relative - // relocations R_MIPS_GPREL16 and R_MIPS_GPREL32. But only R_MIPS_GPREL16 - // can be against a preemptible symbol. - // To get MIPS relocation type we apply 0xff mask. In case of O32 ABI all - // relocation types occupy eight bit. In case of N64 ABI we extract first - // relocation from 3-in-1 packet because only the first relocation can - // be against a real symbol. - if (Config->EMachine == EM_MIPS) { - Type &= 0xff; - if (Type == R_MIPS_GPREL16 || Type == R_MICROMIPS_GPREL16 || - Type == R_MICROMIPS_GPREL7_S2) - return false; - } - return Body.IsPreemptible; +// This is a MIPS-specific rule. +// +// In case of MIPS GP-relative relocations always resolve to a definition +// in a regular input file, ignoring the one-definition rule. So we, +// for example, should not attempt to create a dynamic relocation even +// if the target symbol is preemptible. There are two two MIPS GP-relative +// relocations R_MIPS_GPREL16 and R_MIPS_GPREL32. But only R_MIPS_GPREL16 +// can be against a preemptible symbol. +// +// To get MIPS relocation type we apply 0xff mask. In case of O32 ABI all +// relocation types occupy eight bit. In case of N64 ABI we extract first +// relocation from 3-in-1 packet because only the first relocation can +// be against a real symbol. +static bool isMipsGprel(RelType Type) { + if (Config->EMachine != EM_MIPS) + return false; + Type &= 0xff; + return Type == R_MIPS_GPREL16 || Type == R_MICROMIPS_GPREL16 || + Type == R_MICROMIPS_GPREL7_S2; } // This function is similar to the `handleTlsRelocation`. MIPS does not @@ -209,13 +210,12 @@ handleTlsRelocation(RelType Type, SymbolBody &Body, InputSectionBase &C, if (Config->EMachine == EM_MIPS) return handleMipsTlsRelocation<ELFT>(Type, Body, C, Offset, Addend, Expr); - bool IsPreemptible = isPreemptible(Body, Type); if (isRelExprOneOf<R_TLSDESC, R_TLSDESC_PAGE, R_TLSDESC_CALL>(Expr) && Config->Shared) { if (InX::Got->addDynTlsEntry(Body)) { uint64_t Off = InX::Got->getGlobalDynOffset(Body); In<ELFT>::RelaDyn->addReloc( - {Target->TlsDescRel, InX::Got, Off, !IsPreemptible, &Body, 0}); + {Target->TlsDescRel, InX::Got, Off, !Body.IsPreemptible, &Body, 0}); } if (Expr != R_TLSDESC_CALL) C.Relocations.push_back({Expr, Type, Offset, Addend, &Body}); @@ -255,7 +255,7 @@ handleTlsRelocation(RelType Type, SymbolBody &Body, InputSectionBase &C, // If the symbol is preemptible we need the dynamic linker to write // the offset too. uint64_t OffsetOff = Off + Config->Wordsize; - if (IsPreemptible) + if (Body.IsPreemptible) In<ELFT>::RelaDyn->addReloc( {Target->TlsOffsetRel, InX::Got, OffsetOff, false, &Body, 0}); else @@ -268,7 +268,7 @@ handleTlsRelocation(RelType Type, SymbolBody &Body, InputSectionBase &C, // Global-Dynamic relocs can be relaxed to Initial-Exec or Local-Exec // depending on the symbol being locally defined or not. - if (IsPreemptible) { + if (Body.IsPreemptible) { C.Relocations.push_back( {Target->adjustRelaxExpr(Type, nullptr, R_RELAX_TLS_GD_TO_IE), Type, Offset, Addend, &Body}); @@ -288,7 +288,7 @@ handleTlsRelocation(RelType Type, SymbolBody &Body, InputSectionBase &C, // Initial-Exec relocs can be relaxed to Local-Exec if the symbol is locally // defined. if (isRelExprOneOf<R_GOT, R_GOT_FROM_END, R_GOT_PC, R_GOT_PAGE_PC>(Expr) && - !Config->Shared && !IsPreemptible) { + !Config->Shared && !Body.IsPreemptible) { C.Relocations.push_back( {R_RELAX_TLS_IE_TO_LE, Type, Offset, Addend, &Body}); return 1; @@ -377,7 +377,7 @@ static bool isStaticLinkTimeConstant(RelExpr E, RelType Type, if (E == R_GOT || E == R_PLT || E == R_TLSDESC) return Target->usesOnlyLowPageBits(Type) || !Config->Pic; - if (isPreemptible(Body, Type)) + if (Body.IsPreemptible) return false; if (!Config->Pic) return true; @@ -858,7 +858,15 @@ static void scanRelocs(InputSectionBase &Sec, ArrayRef<RelTy> Rels) { if (isRelExprOneOf<R_HINT, R_NONE>(Expr)) continue; - bool Preemptible = isPreemptible(Body, Type); + // Handle yet another MIPS-ness. + if (isMipsGprel(Type)) { + int64_t Addend = computeAddend<ELFT>(Rel, Sec.Data.data()) + + computeMipsAddend<ELFT>(Rel, Sec, Expr, Body, End); + Sec.Relocations.push_back({R_MIPS_GOTREL, Type, Offset, Addend, &Body}); + continue; + } + + bool Preemptible = Body.IsPreemptible; // Strenghten or relax a PLT access. // @@ -931,7 +939,7 @@ static void scanRelocs(InputSectionBase &Sec, ArrayRef<RelTy> Rels) { } } - if (!needsPlt(Expr) && !needsGot(Expr) && isPreemptible(Body, Type)) { + if (!needsPlt(Expr) && !needsGot(Expr) && Body.IsPreemptible) { // We don't know anything about the finaly symbol. Just ask the dynamic // linker to handle the relocation for us. if (!Target->isPicRel(Type)) |
