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[SOL] Debug sections relocations #32

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Merged
merged 1 commit into from
Apr 21, 2022
Merged

[SOL] Debug sections relocations #32

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17 changes: 17 additions & 0 deletions lld/ELF/Arch/BPF.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,9 @@ RelExpr BPF::getRelExpr(RelType type, const Symbol &s,
switch (type) {
case R_BPF_64_32:
return R_PC;
case R_BPF_64_ABS32:
case R_BPF_64_NODYLD32:
case R_BPF_64_ABS64:
case R_BPF_64_64:
return R_ABS;
default:
Expand All @@ -68,6 +71,12 @@ void BPF::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
write32le(loc + 4, ((val - 8) / 8) & 0xFFFFFFFF);
break;
}
case R_BPF_64_ABS32:
case R_BPF_64_NODYLD32: {
// Relocation used by .BTF.ext and DWARF
write32le(loc, val & 0xFFFFFFFF);
break;
}
case R_BPF_64_64: {
// Relocation of a lddw instruction
// 64 bit address is divided into the imm of this and the following
Expand All @@ -76,6 +85,14 @@ void BPF::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
write32le(loc + 8 + 4, val >> 32);
break;
}
case R_BPF_64_ABS64: {
// The relocation type is used for normal 64-bit data. The
// actual to-be-relocated data is stored at r_offset and the
// read/write data bitsize is 64 (8 bytes). The relocation can
// be resolved with the symbol value plus implicit addend.
write64le(loc, val);
break;
}
default:
error(getErrorLocation(loc) + "unrecognized reloc " + toString(rel.type));
}
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6 changes: 6 additions & 0 deletions llvm/lib/MC/ELFObjectWriter.cpp
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Expand Up @@ -1455,6 +1455,12 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm,
return;

unsigned Type = TargetObjectWriter->getRelocType(Ctx, Target, Fixup, IsPCRel);

unsigned Flags = FixupSection.getFlags();
// Change R_BPF_64_64 relocations in .debug_* sections to R_BPF_64_ABS64
if (Ctx.getTargetTriple().isBPF() && !(Flags & ELF::SHF_ALLOC) && (Type==ELF::R_BPF_64_64))
Type = ELF::R_BPF_64_ABS64;

const auto *Parent = cast<MCSectionELF>(Fragment->getParent());
// Emiting relocation with sybmol for CG Profile to help with --cg-profile.
bool RelocateWithSymbol =
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3 changes: 1 addition & 2 deletions llvm/lib/Target/BPF/BPFTargetMachine.cpp
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Expand Up @@ -83,8 +83,7 @@ BPFTargetMachine::BPFTargetMachine(const Target &T, const Triple &TT,
BPFMCAsmInfo *MAI =
static_cast<BPFMCAsmInfo *>(const_cast<MCAsmInfo *>(AsmInfo.get()));
MAI->setDwarfUsesRelocationsAcrossSections(!Subtarget.getUseDwarfRIS());
bool IsSolana = TT.getArch() == Triple::sbf || FS.contains("solana");
MAI->setSupportsDebugInformation(!IsSolana);
MAI->setSupportsDebugInformation(true);
}

namespace {
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3 changes: 3 additions & 0 deletions llvm/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp
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Expand Up @@ -92,6 +92,9 @@ unsigned BPFELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target,
if ((Flags & ELF::SHF_ALLOC) && (Flags & ELF::SHF_WRITE))
return ELF::R_BPF_64_NODYLD32;
}
// .debug_* sections
if (!(Flags & ELF::SHF_ALLOC))
return ELF::R_BPF_64_ABS32;
}
}
return isSolana ? ELF::R_BPF_64_32 : ELF::R_BPF_64_ABS32;
Expand Down