| // Inferno utils/5l/asm.c |
| // https://bitbucket.org/inferno-os/inferno-os/src/master/utils/5l/asm.c |
| // |
| // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. |
| // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) |
| // Portions Copyright © 1997-1999 Vita Nuova Limited |
| // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) |
| // Portions Copyright © 2004,2006 Bruce Ellis |
| // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) |
| // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others |
| // Portions Copyright © 2009 The Go Authors. All rights reserved. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| package mips64 |
| |
| import ( |
| "cmd/internal/objabi" |
| "cmd/internal/sys" |
| "cmd/link/internal/ld" |
| "cmd/link/internal/loader" |
| "cmd/link/internal/sym" |
| "debug/elf" |
| ) |
| |
| var ( |
| // dtOffsets contains offsets for entries within the .dynamic section. |
| // These are used to fix up symbol values once they are known. |
| dtOffsets map[elf.DynTag]int64 |
| |
| // dynSymCount contains the number of entries in the .dynsym section. |
| // This is used to populate the DT_MIPS_SYMTABNO entry in the .dynamic |
| // section. |
| dynSymCount uint64 |
| |
| // gotLocalCount contains the number of local global offset table |
| // entries. This is used to populate the DT_MIPS_LOCAL_GOTNO entry in |
| // the .dynamic section. |
| gotLocalCount uint64 |
| |
| // gotSymIndex contains the index of the first dynamic symbol table |
| // entry that corresponds to an entry in the global offset table. |
| // This is used to populate the DT_MIPS_GOTSYM entry in the .dynamic |
| // section. |
| gotSymIndex uint64 |
| ) |
| |
| func gentext(ctxt *ld.Link, ldr *loader.Loader) { |
| if *ld.FlagD || ctxt.Target.IsExternal() { |
| return |
| } |
| |
| dynamic := ldr.MakeSymbolUpdater(ctxt.ArchSyms.Dynamic) |
| |
| ld.Elfwritedynent(ctxt.Arch, dynamic, elf.DT_MIPS_RLD_VERSION, 1) |
| ld.Elfwritedynent(ctxt.Arch, dynamic, elf.DT_MIPS_BASE_ADDRESS, 0) |
| |
| // elfsetupplt should have been called and gotLocalCount should now |
| // have its correct value. |
| if gotLocalCount == 0 { |
| ctxt.Errorf(0, "internal error: elfsetupplt has not been called") |
| } |
| ld.Elfwritedynent(ctxt.Arch, dynamic, elf.DT_MIPS_LOCAL_GOTNO, gotLocalCount) |
| |
| // DT_* entries have to exist prior to elfdynhash(), which finalises the |
| // table by adding DT_NULL. However, the values for the following entries |
| // are not know until after dynreloc() has completed. Add the symbols now, |
| // then update their values prior to code generation. |
| dts := []elf.DynTag{ |
| elf.DT_MIPS_SYMTABNO, |
| elf.DT_MIPS_GOTSYM, |
| } |
| dtOffsets = make(map[elf.DynTag]int64) |
| for _, dt := range dts { |
| ld.Elfwritedynent(ctxt.Arch, dynamic, dt, 0) |
| dtOffsets[dt] = dynamic.Size() - 8 |
| } |
| } |
| |
| 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) |
| } |
| |
| if r.Type() >= objabi.ElfRelocOffset { |
| ldr.Errorf(s, "unexpected relocation type %d (%s)", r.Type(), sym.RelocName(target.Arch, r.Type())) |
| return false |
| } |
| |
| switch r.Type() { |
| case objabi.R_CALLMIPS, objabi.R_JMPMIPS: |
| if targType != sym.SDYNIMPORT { |
| // Nothing to do, the relocation will be laid out in reloc |
| return true |
| } |
| if target.IsExternal() { |
| // External linker will do this relocation. |
| return true |
| } |
| |
| // Internal linking, build a PLT entry and change the relocation |
| // target to that entry. |
| if r.Add() != 0 { |
| ldr.Errorf(s, "PLT call with non-zero addend (%v)", r.Add()) |
| } |
| addpltsym(target, ldr, syms, targ) |
| su := ldr.MakeSymbolUpdater(s) |
| su.SetRelocSym(rIdx, syms.PLT) |
| su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ))) |
| return true |
| } |
| |
| return false |
| } |
| |
| func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym, r loader.ExtReloc, ri int, sectoff int64) bool { |
| |
| // mips64 ELF relocation (endian neutral) |
| // offset uint64 |
| // sym uint32 |
| // ssym uint8 |
| // type3 uint8 |
| // type2 uint8 |
| // type uint8 |
| // addend int64 |
| |
| addend := r.Xadd |
| |
| out.Write64(uint64(sectoff)) |
| |
| elfsym := ld.ElfSymForReloc(ctxt, r.Xsym) |
| out.Write32(uint32(elfsym)) |
| out.Write8(0) |
| out.Write8(0) |
| out.Write8(0) |
| switch r.Type { |
| default: |
| return false |
| case objabi.R_ADDR, objabi.R_DWARFSECREF: |
| switch r.Size { |
| case 4: |
| out.Write8(uint8(elf.R_MIPS_32)) |
| case 8: |
| out.Write8(uint8(elf.R_MIPS_64)) |
| default: |
| return false |
| } |
| case objabi.R_ADDRMIPS: |
| out.Write8(uint8(elf.R_MIPS_LO16)) |
| case objabi.R_ADDRMIPSU: |
| out.Write8(uint8(elf.R_MIPS_HI16)) |
| case objabi.R_ADDRMIPSTLS: |
| out.Write8(uint8(elf.R_MIPS_TLS_TPREL_LO16)) |
| if ctxt.Target.IsOpenbsd() { |
| // OpenBSD mips64 does not currently offset TLS by 0x7000, |
| // as such we need to add this back to get the correct offset |
| // via the external linker. |
| addend += 0x7000 |
| } |
| case objabi.R_CALLMIPS, |
| objabi.R_JMPMIPS: |
| out.Write8(uint8(elf.R_MIPS_26)) |
| } |
| out.Write64(uint64(addend)) |
| |
| return true |
| } |
| |
| func elfsetupplt(ctxt *ld.Link, ldr *loader.Loader, plt, gotplt *loader.SymbolBuilder, dynamic loader.Sym) { |
| if plt.Size() != 0 { |
| return |
| } |
| |
| // Load resolver address from got[0] into r25. |
| plt.AddSymRef(ctxt.Arch, gotplt.Sym(), 0, objabi.R_ADDRMIPSU, 4) |
| plt.SetUint32(ctxt.Arch, plt.Size()-4, 0x3c0e0000) // lui $14, %hi(&GOTPLT[0]) |
| plt.AddSymRef(ctxt.Arch, gotplt.Sym(), 0, objabi.R_ADDRMIPS, 4) |
| plt.SetUint32(ctxt.Arch, plt.Size()-4, 0xddd90000) // ld $25, %lo(&GOTPLT[0])($14) |
| |
| // Load return address into r15, the index of the got.plt entry into r24, then |
| // JALR to the resolver. The address of the got.plt entry is currently in r24, |
| // which we have to turn into an index. |
| plt.AddSymRef(ctxt.Arch, gotplt.Sym(), 0, objabi.R_ADDRMIPS, 4) |
| plt.SetUint32(ctxt.Arch, plt.Size()-4, 0x25ce0000) // addiu $14, $14, %lo(&GOTPLT[0]) |
| plt.AddUint32(ctxt.Arch, 0x030ec023) // subu $24, $24, $14 |
| plt.AddUint32(ctxt.Arch, 0x03e07825) // move $15, $31 |
| plt.AddUint32(ctxt.Arch, 0x0018c0c2) // srl $24, $24, 3 |
| plt.AddUint32(ctxt.Arch, 0x0320f809) // jalr $25 |
| plt.AddUint32(ctxt.Arch, 0x2718fffe) // subu $24, $24, 2 |
| |
| if gotplt.Size() != 0 { |
| ctxt.Errorf(gotplt.Sym(), "got.plt is not empty") |
| } |
| |
| // Reserve got[0] for resolver address (populated by dynamic loader). |
| gotplt.AddUint32(ctxt.Arch, 0) |
| gotplt.AddUint32(ctxt.Arch, 0) |
| gotLocalCount++ |
| |
| // Reserve got[1] for ELF object pointer (populated by dynamic loader). |
| gotplt.AddUint32(ctxt.Arch, 0) |
| gotplt.AddUint32(ctxt.Arch, 0) |
| gotLocalCount++ |
| } |
| |
| func addpltsym(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loader.Sym) { |
| if ldr.SymPlt(s) >= 0 { |
| return |
| } |
| |
| dynamic := ldr.MakeSymbolUpdater(syms.Dynamic) |
| |
| const dynSymEntrySize = 20 |
| if gotSymIndex == 0 { |
| // Compute and update GOT symbol index. |
| gotSymIndex = uint64(ldr.SymSize(syms.DynSym) / dynSymEntrySize) |
| dynamic.SetUint(target.Arch, dtOffsets[elf.DT_MIPS_GOTSYM], gotSymIndex) |
| } |
| if dynSymCount == 0 { |
| dynSymCount = uint64(ldr.SymSize(syms.DynSym) / dynSymEntrySize) |
| } |
| |
| ld.Adddynsym(ldr, target, syms, s) |
| dynSymCount++ |
| |
| if !target.IsElf() { |
| ldr.Errorf(s, "addpltsym: unsupported binary format") |
| } |
| |
| plt := ldr.MakeSymbolUpdater(syms.PLT) |
| gotplt := ldr.MakeSymbolUpdater(syms.GOTPLT) |
| if plt.Size() == 0 { |
| panic("plt is not set up") |
| } |
| |
| // Load got.plt entry into r25. |
| plt.AddSymRef(target.Arch, gotplt.Sym(), gotplt.Size(), objabi.R_ADDRMIPSU, 4) |
| plt.SetUint32(target.Arch, plt.Size()-4, 0x3c0f0000) // lui $15, %hi(.got.plt entry) |
| plt.AddSymRef(target.Arch, gotplt.Sym(), gotplt.Size(), objabi.R_ADDRMIPS, 4) |
| plt.SetUint32(target.Arch, plt.Size()-4, 0xddf90000) // ld $25, %lo(.got.plt entry)($15) |
| |
| // Load address of got.plt entry into r24 and JALR to address in r25. |
| plt.AddUint32(target.Arch, 0x03200008) // jr $25 |
| plt.AddSymRef(target.Arch, gotplt.Sym(), gotplt.Size(), objabi.R_ADDRMIPS, 4) |
| plt.SetUint32(target.Arch, plt.Size()-4, 0x65f80000) // daddiu $24, $15, %lo(.got.plt entry) |
| |
| // Add pointer to plt[0] to got.plt |
| gotplt.AddAddrPlus(target.Arch, plt.Sym(), 0) |
| |
| ldr.SetPlt(s, int32(plt.Size()-16)) |
| |
| // Update dynamic symbol count. |
| dynamic.SetUint(target.Arch, dtOffsets[elf.DT_MIPS_SYMTABNO], dynSymCount) |
| } |
| |
| func machoreloc1(*sys.Arch, *ld.OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int64) bool { |
| return false |
| } |
| |
| func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loader.Reloc, s loader.Sym, val int64) (o int64, nExtReloc int, ok bool) { |
| if target.IsExternal() { |
| switch r.Type() { |
| default: |
| return val, 0, false |
| |
| case objabi.R_ADDRMIPS, |
| objabi.R_ADDRMIPSU, |
| objabi.R_ADDRMIPSTLS, |
| objabi.R_CALLMIPS, |
| objabi.R_JMPMIPS: |
| return val, 1, true |
| } |
| } |
| |
| const isOk = true |
| const noExtReloc = 0 |
| rs := r.Sym() |
| switch r.Type() { |
| case objabi.R_ADDRMIPS, |
| objabi.R_ADDRMIPSU: |
| t := ldr.SymValue(rs) + r.Add() |
| if r.Type() == objabi.R_ADDRMIPS { |
| return int64(val&0xffff0000 | t&0xffff), noExtReloc, isOk |
| } |
| return int64(val&0xffff0000 | ((t+1<<15)>>16)&0xffff), noExtReloc, isOk |
| case objabi.R_ADDRMIPSTLS: |
| // thread pointer is at 0x7000 offset from the start of TLS data area |
| t := ldr.SymValue(rs) + r.Add() - 0x7000 |
| if target.IsOpenbsd() { |
| // OpenBSD mips64 does not currently offset TLS by 0x7000, |
| // as such we need to add this back to get the correct offset. |
| t += 0x7000 |
| } |
| if t < -32768 || t >= 32678 { |
| ldr.Errorf(s, "TLS offset out of range %d", t) |
| } |
| return int64(val&0xffff0000 | t&0xffff), noExtReloc, isOk |
| case objabi.R_CALLMIPS, |
| objabi.R_JMPMIPS: |
| // Low 26 bits = (S + A) >> 2 |
| t := ldr.SymValue(rs) + r.Add() |
| return int64(val&0xfc000000 | (t>>2)&^0xfc000000), noExtReloc, isOk |
| } |
| |
| return val, 0, false |
| } |
| |
| func archrelocvariant(*ld.Target, *loader.Loader, loader.Reloc, sym.RelocVariant, loader.Sym, int64, []byte) int64 { |
| return -1 |
| } |
| |
| func extreloc(target *ld.Target, ldr *loader.Loader, r loader.Reloc, s loader.Sym) (loader.ExtReloc, bool) { |
| switch r.Type() { |
| case objabi.R_ADDRMIPS, |
| objabi.R_ADDRMIPSU: |
| return ld.ExtrelocViaOuterSym(ldr, r, s), true |
| |
| case objabi.R_ADDRMIPSTLS, |
| objabi.R_CALLMIPS, |
| objabi.R_JMPMIPS: |
| return ld.ExtrelocSimple(ldr, r), true |
| } |
| return loader.ExtReloc{}, false |
| } |
