diff options
| author | Katie Hockman <katie@golang.org> | 2020-12-14 10:03:05 -0500 |
|---|---|---|
| committer | Katie Hockman <katie@golang.org> | 2020-12-14 10:06:13 -0500 |
| commit | 0345ede87ee12698988973884cfc0fd3d499dffd (patch) | |
| tree | 7123cff141ee5661208d2f5f437b8f5252ac7f6a /src/cmd/link/internal/arm64 | |
| parent | 4651d6b267818b0e0d128a5443289717c4bb8cbc (diff) | |
| parent | 0a02371b0576964e81c3b40d328db9a3ef3b031b (diff) | |
| download | go-0345ede87ee12698988973884cfc0fd3d499dffd.tar.xz | |
[dev.fuzz] all: merge master into dev.fuzz
Change-Id: I5d8c8329ccc9d747bd81ade6b1cb7cb8ae2e94b2
Diffstat (limited to 'src/cmd/link/internal/arm64')
| -rw-r--r-- | src/cmd/link/internal/arm64/asm.go | 188 | ||||
| -rw-r--r-- | src/cmd/link/internal/arm64/obj.go | 2 |
2 files changed, 181 insertions, 9 deletions
diff --git a/src/cmd/link/internal/arm64/asm.go b/src/cmd/link/internal/arm64/asm.go index 945b83822c..30819db4c6 100644 --- a/src/cmd/link/internal/arm64/asm.go +++ b/src/cmd/link/internal/arm64/asm.go @@ -71,13 +71,13 @@ func gentext(ctxt *ld.Link, ldr *loader.Loader) { } func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym, r loader.Reloc, rIdx int) bool { - targ := r.Sym() var targType sym.SymKind if targ != 0 { targType = ldr.SymType(targ) } + const pcrel = 1 switch r.Type() { default: if r.Type() >= objabi.ElfRelocOffset { @@ -177,6 +177,14 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade su.SetRelocType(rIdx, objabi.R_ARM64_LDST8) return true + case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST16_ABS_LO12_NC): + if targType == sym.SDYNIMPORT { + ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ)) + } + su := ldr.MakeSymbolUpdater(s) + su.SetRelocType(rIdx, objabi.R_ARM64_LDST16) + return true + case objabi.ElfRelocOffset + objabi.RelocType(elf.R_AARCH64_LDST32_ABS_LO12_NC): if targType == sym.SDYNIMPORT { ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ)) @@ -201,6 +209,75 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade su := ldr.MakeSymbolUpdater(s) su.SetRelocType(rIdx, objabi.R_ARM64_LDST128) return true + + // Handle relocations found in Mach-O object files. + case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_UNSIGNED*2: + if targType == sym.SDYNIMPORT { + ldr.Errorf(s, "unexpected reloc for dynamic symbol %s", ldr.SymName(targ)) + } + su := ldr.MakeSymbolUpdater(s) + su.SetRelocType(rIdx, objabi.R_ADDR) + if target.IsPIE() && target.IsInternal() { + // For internal linking PIE, this R_ADDR relocation cannot + // be resolved statically. We need to generate a dynamic + // relocation. Let the code below handle it. + break + } + return true + + case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_BRANCH26*2 + pcrel: + su := ldr.MakeSymbolUpdater(s) + su.SetRelocType(rIdx, objabi.R_CALLARM64) + if targType == sym.SDYNIMPORT { + addpltsym(target, ldr, syms, targ) + su.SetRelocSym(rIdx, syms.PLT) + su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ))) + } + return true + + case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_PAGE21*2 + pcrel, + objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_PAGEOFF12*2: + if targType == sym.SDYNIMPORT { + ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ)) + } + su := ldr.MakeSymbolUpdater(s) + su.SetRelocType(rIdx, objabi.R_ARM64_PCREL) + return true + + case objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGE21*2 + pcrel, + objabi.MachoRelocOffset + ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12*2: + if targType != sym.SDYNIMPORT { + // have symbol + // turn MOVD sym@GOT (adrp+ldr) into MOVD $sym (adrp+add) + data := ldr.Data(s) + off := r.Off() + if int(off+3) >= len(data) { + ldr.Errorf(s, "unexpected GOT_LOAD reloc for non-dynamic symbol %s", ldr.SymName(targ)) + return false + } + o := target.Arch.ByteOrder.Uint32(data[off:]) + su := ldr.MakeSymbolUpdater(s) + switch { + case (o>>24)&0x9f == 0x90: // adrp + // keep instruction unchanged, change relocation type below + case o>>24 == 0xf9: // ldr + // rewrite to add + o = (0x91 << 24) | (o & (1<<22 - 1)) + su.MakeWritable() + su.SetUint32(target.Arch, int64(off), o) + default: + ldr.Errorf(s, "unexpected GOT_LOAD reloc for non-dynamic symbol %s", ldr.SymName(targ)) + return false + } + su.SetRelocType(rIdx, objabi.R_ARM64_PCREL) + return true + } + ld.AddGotSym(target, ldr, syms, targ, 0) + su := ldr.MakeSymbolUpdater(s) + su.SetRelocType(rIdx, objabi.R_ARM64_GOT) + su.SetRelocSym(rIdx, syms.GOT) + su.SetRelocAdd(rIdx, int64(ldr.SymGot(targ))) + return true } // Reread the reloc to incorporate any changes in type above. @@ -219,6 +296,16 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade // External linker will do this relocation. return true } + // Internal linking. + if r.Add() != 0 { + ldr.Errorf(s, "PLT call with non-zero addend (%v)", r.Add()) + } + // Build a PLT entry and change the relocation target to that entry. + addpltsym(target, ldr, syms, targ) + su := ldr.MakeSymbolUpdater(s) + su.SetRelocSym(rIdx, syms.PLT) + su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ))) + return true case objabi.R_ADDR: if ldr.SymType(s) == sym.STEXT && target.IsElf() { @@ -302,7 +389,7 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade rela := ldr.MakeSymbolUpdater(syms.Rela) rela.AddAddrPlus(target.Arch, s, int64(r.Off())) if r.Siz() == 8 { - rela.AddUint64(target.Arch, ld.ELF64_R_INFO(0, uint32(elf.R_AARCH64_RELATIVE))) + rela.AddUint64(target.Arch, elf.R_INFO(0, uint32(elf.R_AARCH64_RELATIVE))) } else { ldr.Errorf(s, "unexpected relocation for dynamic symbol %s", ldr.SymName(targ)) } @@ -313,6 +400,18 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade // (e.g. go version). return true } + + if target.IsDarwin() { + // Mach-O relocations are a royal pain to lay out. + // They use a compact stateful bytecode representation. + // Here we record what are needed and encode them later. + ld.MachoAddRebase(s, int64(r.Off())) + // Not mark r done here. So we still apply it statically, + // so in the file content we'll also have the right offset + // to the relocation target. So it can be examined statically + // (e.g. go version). + return true + } } return false } @@ -364,6 +463,9 @@ func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, return true } +// sign-extends from 24-bit. +func signext24(x int64) int64 { return x << 40 >> 40 } + func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, sectoff int64) bool { var v uint32 @@ -371,7 +473,7 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy rt := r.Type siz := r.Size - if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_CALLARM64 || rt == objabi.R_ADDRARM64 { + if ldr.SymType(rs) == sym.SHOSTOBJ || rt == objabi.R_CALLARM64 || rt == objabi.R_ADDRARM64 || rt == objabi.R_ARM64_GOTPCREL { if ldr.SymDynid(rs) < 0 { ldr.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", rt, sym.RelocName(arch, rt), ldr.SymName(rs), ldr.SymType(rs), ldr.SymType(rs)) return false @@ -387,6 +489,10 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy } } + if r.Xadd != signext24(r.Xadd) { + ldr.Errorf(s, "relocation addend overflow: %s+0x%x", ldr.SymName(rs), r.Xadd) + } + switch rt { default: return false @@ -415,6 +521,22 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, ldr *loader.Loader, s loader.Sy } v |= 1 << 24 // pc-relative bit v |= ld.MACHO_ARM64_RELOC_PAGE21 << 28 + case objabi.R_ARM64_GOTPCREL: + siz = 4 + // Two relocation entries: MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12 MACHO_ARM64_RELOC_GOT_LOAD_PAGE21 + // if r.Xadd is non-zero, add two MACHO_ARM64_RELOC_ADDEND. + if r.Xadd != 0 { + out.Write32(uint32(sectoff + 4)) + out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff)) + } + out.Write32(uint32(sectoff + 4)) + out.Write32(v | (ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGEOFF12 << 28) | (2 << 25)) + if r.Xadd != 0 { + out.Write32(uint32(sectoff)) + out.Write32((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff)) + } + v |= 1 << 24 // pc-relative bit + v |= ld.MACHO_ARM64_RELOC_GOT_LOAD_PAGE21 << 28 } switch siz { @@ -457,7 +579,7 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade } nExtReloc = 2 // need two ELF/Mach-O relocations. see elfreloc1/machoreloc1 - if target.IsDarwin() && rt == objabi.R_ADDRARM64 && xadd != 0 { + if target.IsDarwin() && xadd != 0 { nExtReloc = 4 // need another two relocations for non-zero addend } @@ -633,14 +755,28 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade } o0 := (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5) return val | int64(o0), noExtReloc, isOk - } else if (val>>24)&0x91 == 0x91 { - // R_AARCH64_ADD_ABS_LO12_NC + } else if (val>>24)&0x9f == 0x91 { + // ELF R_AARCH64_ADD_ABS_LO12_NC or Mach-O ARM64_RELOC_PAGEOFF12 // patch instruction: add t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff) o1 := uint32(t&0xfff) << 10 return val | int64(o1), noExtReloc, isOk + } else if (val>>24)&0x3b == 0x39 { + // Mach-O ARM64_RELOC_PAGEOFF12 + // patch ldr/str(b/h/w/d/q) (integer or vector) instructions, which have different scaling factors. + // Mach-O uses same relocation type for them. + shift := uint32(val) >> 30 + if shift == 0 && (val>>20)&0x048 == 0x048 { // 128-bit vector load + shift = 4 + } + t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff) + if t&(1<<shift-1) != 0 { + ldr.Errorf(s, "invalid address: %x for relocation type: ARM64_RELOC_PAGEOFF12", t) + } + o1 := (uint32(t&0xfff) >> shift) << 10 + return val | int64(o1), noExtReloc, isOk } else { - ldr.Errorf(s, "unsupported instruction for %x R_PCRELARM64", val) + ldr.Errorf(s, "unsupported instruction for %x R_ARM64_PCREL", val) } case objabi.R_ARM64_LDST8: @@ -648,6 +784,14 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade o0 := uint32(t&0xfff) << 10 return val | int64(o0), noExtReloc, true + case objabi.R_ARM64_LDST16: + t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff) + if t&1 != 0 { + ldr.Errorf(s, "invalid address: %x for relocation type: R_AARCH64_LDST16_ABS_LO12_NC", t) + } + o0 := (uint32(t&0xfff) >> 1) << 10 + return val | int64(o0), noExtReloc, true + case objabi.R_ARM64_LDST32: t := ldr.SymAddr(rs) + r.Add() - ((ldr.SymValue(s) + int64(r.Off())) &^ 0xfff) if t&3 != 0 { @@ -792,10 +936,38 @@ func addpltsym(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade rela.AddAddrPlus(target.Arch, gotplt.Sym(), gotplt.Size()-8) sDynid := ldr.SymDynid(s) - rela.AddUint64(target.Arch, ld.ELF64_R_INFO(uint32(sDynid), uint32(elf.R_AARCH64_JUMP_SLOT))) + rela.AddUint64(target.Arch, elf.R_INFO(uint32(sDynid), uint32(elf.R_AARCH64_JUMP_SLOT))) rela.AddUint64(target.Arch, 0) ldr.SetPlt(s, int32(plt.Size()-16)) + } else if target.IsDarwin() { + ld.AddGotSym(target, ldr, syms, s, 0) + + sDynid := ldr.SymDynid(s) + lep := ldr.MakeSymbolUpdater(syms.LinkEditPLT) + lep.AddUint32(target.Arch, uint32(sDynid)) + + plt := ldr.MakeSymbolUpdater(syms.PLT) + ldr.SetPlt(s, int32(plt.Size())) + + // adrp x16, GOT + plt.AddUint32(target.Arch, 0x90000010) + r, _ := plt.AddRel(objabi.R_ARM64_GOT) + r.SetOff(int32(plt.Size() - 4)) + r.SetSiz(4) + r.SetSym(syms.GOT) + r.SetAdd(int64(ldr.SymGot(s))) + + // ldr x17, [x16, <offset>] + plt.AddUint32(target.Arch, 0xf9400211) + r, _ = plt.AddRel(objabi.R_ARM64_GOT) + r.SetOff(int32(plt.Size() - 4)) + r.SetSiz(4) + r.SetSym(syms.GOT) + r.SetAdd(int64(ldr.SymGot(s))) + + // br x17 + plt.AddUint32(target.Arch, 0xd61f0220) } else { ldr.Errorf(s, "addpltsym: unsupported binary format") } diff --git a/src/cmd/link/internal/arm64/obj.go b/src/cmd/link/internal/arm64/obj.go index a980cfee52..ab3dfd99f7 100644 --- a/src/cmd/link/internal/arm64/obj.go +++ b/src/cmd/link/internal/arm64/obj.go @@ -102,7 +102,7 @@ func archinit(ctxt *ld.Link) { case objabi.Hdarwin: /* apple MACH */ ld.HEADR = ld.INITIAL_MACHO_HEADR if *ld.FlagTextAddr == -1 { - *ld.FlagTextAddr = 4096 + int64(ld.HEADR) + *ld.FlagTextAddr = 1<<32 + int64(ld.HEADR) } if *ld.FlagRound == -1 { *ld.FlagRound = 16384 // 16K page alignment |
