func machoreloc1(r *ld.Reloc, sectoff int64) int {
var v uint32
rs := r.Xsym
if rs.Type == obj.SHOSTOBJ || r.Type == obj.R_PCREL {
if rs.Dynid < 0 {
ld.Diag("reloc %d to non-macho symbol %s type=%d", r.Type, rs.Name, rs.Type)
return -1
}
v = uint32(rs.Dynid)
v |= 1 << 27 // external relocation
} else {
v = uint32(rs.Sect.Extnum)
if v == 0 {
ld.Diag("reloc %d to symbol %s in non-macho section %s type=%d", r.Type, rs.Name, rs.Sect.Name, rs.Type)
return -1
}
}
switch r.Type {
default:
return -1
case obj.R_ADDR:
v |= ld.MACHO_X86_64_RELOC_UNSIGNED << 28
case obj.R_CALL:
v |= 1 << 24 // pc-relative bit
v |= ld.MACHO_X86_64_RELOC_BRANCH << 28
// NOTE: Only works with 'external' relocation. Forced above.
case obj.R_PCREL:
v |= 1 << 24 // pc-relative bit
v |= ld.MACHO_X86_64_RELOC_SIGNED << 28
}
switch r.Siz {
default:
return -1
case 1:
v |= 0 << 25
case 2:
v |= 1 << 25
case 4:
v |= 2 << 25
case 8:
v |= 3 << 25
}
ld.Thearch.Lput(uint32(sectoff))
ld.Thearch.Lput(v)
return 0
}
func machoreloc1(r *ld.Reloc, sectoff int64) int {
var v uint32
rs := r.Xsym
if rs.Type == obj.SHOSTOBJ {
if rs.Dynid < 0 {
ld.Diag("reloc %d to non-macho symbol %s type=%d", r.Type, rs.Name, rs.Type)
return -1
}
v = uint32(rs.Dynid)
v |= 1 << 27 // external relocation
} else {
v = uint32(rs.Sect.Extnum)
if v == 0 {
ld.Diag("reloc %d to symbol %s in non-macho section %s type=%d", r.Type, rs.Name, rs.Sect.Name, rs.Type)
return -1
}
}
switch r.Type {
default:
return -1
case obj.R_ADDR:
v |= ld.MACHO_GENERIC_RELOC_VANILLA << 28
case obj.R_CALL,
obj.R_PCREL:
v |= 1 << 24 // pc-relative bit
v |= ld.MACHO_GENERIC_RELOC_VANILLA << 28
}
switch r.Siz {
default:
return -1
case 1:
v |= 0 << 25
case 2:
v |= 1 << 25
case 4:
v |= 2 << 25
case 8:
v |= 3 << 25
}
ld.Thearch.Lput(uint32(sectoff))
ld.Thearch.Lput(v)
return 0
}
func archrelocaddr(r *ld.Reloc, s *ld.LSym, val *int64) int {
var o1, o2 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o1 = uint32(*val >> 32)
o2 = uint32(*val)
} else {
o1 = uint32(*val)
o2 = uint32(*val >> 32)
}
// We are inserting an address into two instructions: adrp and
// then either addi or a load.
address := ld.Symaddr(r.Sym) + r.Add
pgaddress := (address &^ 0xfff) - ((s.Value + int64(r.Off)) &^ 0xfff)
if pgaddress < -1<<31 || pgaddress >= 1<<31 {
ld.Ctxt.Diag("relocation for %s is too big (>=2G): %d", s.Name, pgaddress)
}
pgoff := uint32(address & 0xfff)
o1 |= uint32((((pgaddress >> 12) & 3) << 29) | (((pgaddress >> 12 >> 2) & 0x7ffff) << 5))
switch r.Type {
case obj.R_ADDRARM64, obj.R_ARM64_LOAD8:
o2 |= pgoff << 10
case obj.R_ARM64_LOAD16:
if pgoff&0x1 != 0 {
ld.Diag("offset for 16-byte load/store has unaligned value %d", pgoff)
}
o2 |= pgoff << 9
case obj.R_ARM64_LOAD32:
if pgoff&0x3 != 0 {
ld.Diag("offset for 32-byte load/store has unaligned value %d", pgoff)
}
o2 |= pgoff << 8
case obj.R_ARM64_LOAD64:
if pgoff&0x7 != 0 {
ld.Diag("offset for 64-byte load/store has unaligned value %d", pgoff)
}
o2 |= pgoff << 7
default:
return -1
}
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o1)<<32 | int64(o2)
} else {
*val = int64(o2)<<32 | int64(o1)
}
return 0
}
func pereloc1(r *ld.Reloc, sectoff int64) bool {
var v uint32
rs := r.Xsym
if rs.Dynid < 0 {
ld.Diag("reloc %d to non-coff symbol %s type=%d", r.Type, rs.Name, rs.Type)
return false
}
ld.Thearch.Lput(uint32(sectoff))
ld.Thearch.Lput(uint32(rs.Dynid))
switch r.Type {
default:
return false
case obj.R_ADDR:
v = ld.IMAGE_REL_I386_DIR32
case obj.R_CALL,
obj.R_PCREL:
v = ld.IMAGE_REL_I386_REL32
}
ld.Thearch.Wput(uint16(v))
return true
}
func archrelocvariant(r *ld.Reloc, s *ld.Symbol, t int64) int64 {
switch r.Variant & ld.RV_TYPE_MASK {
default:
ld.Diag("unexpected relocation variant %d", r.Variant)
return t
case ld.RV_NONE:
return t
case ld.RV_390_DBL:
if (t & 1) != 0 {
ld.Diag("%s+%v is not 2-byte aligned", r.Sym.Name, r.Sym.Value)
}
return t >> 1
}
}
func addpltsym(ctxt *ld.Link, s *ld.LSym) {
if s.Plt >= 0 {
return
}
ld.Adddynsym(ctxt, s)
if ld.Iself {
plt := ld.Linklookup(ctxt, ".plt", 0)
got := ld.Linklookup(ctxt, ".got.plt", 0)
rel := ld.Linklookup(ctxt, ".rel.plt", 0)
if plt.Size == 0 {
elfsetupplt()
}
// jmpq *got+size
ld.Adduint8(ctxt, plt, 0xff)
ld.Adduint8(ctxt, plt, 0x25)
ld.Addaddrplus(ctxt, plt, got, got.Size)
// add to got: pointer to current pos in plt
ld.Addaddrplus(ctxt, got, plt, plt.Size)
// pushl $x
ld.Adduint8(ctxt, plt, 0x68)
ld.Adduint32(ctxt, plt, uint32(rel.Size))
// jmp .plt
ld.Adduint8(ctxt, plt, 0xe9)
ld.Adduint32(ctxt, plt, uint32(-(plt.Size + 4)))
// rel
ld.Addaddrplus(ctxt, rel, got, got.Size-4)
ld.Adduint32(ctxt, rel, ld.ELF32_R_INFO(uint32(s.Dynid), ld.R_386_JMP_SLOT))
s.Plt = int32(plt.Size - 16)
} else if ld.HEADTYPE == obj.Hdarwin {
// Same laziness as in 6l.
plt := ld.Linklookup(ctxt, ".plt", 0)
addgotsym(ctxt, s)
ld.Adduint32(ctxt, ld.Linklookup(ctxt, ".linkedit.plt", 0), uint32(s.Dynid))
// jmpq *got+size(IP)
s.Plt = int32(plt.Size)
ld.Adduint8(ctxt, plt, 0xff)
ld.Adduint8(ctxt, plt, 0x25)
ld.Addaddrplus(ctxt, plt, ld.Linklookup(ctxt, ".got", 0), int64(s.Got))
} else {
ld.Diag("addpltsym: unsupported binary format")
}
}
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
// TODO(minux): translate R_ADDRPOWER and R_CALLPOWER into standard ELF relocations.
// R_ADDRPOWER corresponds to R_PPC_ADDR16_HA and R_PPC_ADDR16_LO.
// R_CALLPOWER corresponds to R_PPC_REL24.
return -1
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
case obj.R_ADDRPOWER, obj.R_ADDRPOWER_DS:
return archrelocaddr(r, s, val)
case obj.R_CALLPOWER:
// Bits 6 through 29 = (S + A - P) >> 2
t := ld.Symaddr(r.Sym) + r.Add - (s.Value + int64(r.Off))
if t&3 != 0 {
ld.Ctxt.Diag("relocation for %s+%d is not aligned: %d", r.Sym.Name, r.Off, t)
}
if int64(int32(t<<6)>>6) != t {
// TODO(austin) This can happen if text > 32M.
// Add a call trampoline to .text in that case.
ld.Ctxt.Diag("relocation for %s+%d is too big: %d", r.Sym.Name, r.Off, t)
}
*val |= int64(uint32(t) &^ 0xfc000003)
return 0
case obj.R_POWER_TOC: // S + A - .TOC.
*val = ld.Symaddr(r.Sym) + r.Add - symtoc(s)
return 0
case obj.R_POWER_TLS_LE:
// The thread pointer points 0x7000 bytes after the start of the the
// thread local storage area as documented in section "3.7.2 TLS
// Runtime Handling" of "Power Architecture 64-Bit ELF V2 ABI
// Specification".
v := r.Sym.Value - 0x7000
if int64(int16(v)) != v {
ld.Diag("TLS offset out of range %d", v)
}
*val = (*val &^ 0xffff) | (v & 0xffff)
return 0
}
return -1
}
func addgotsyminternal(ctxt *ld.Link, s *ld.LSym) {
if s.Got >= 0 {
return
}
got := ld.Linklookup(ctxt, ".got", 0)
s.Got = int32(got.Size)
ld.Addaddrplus(ctxt, got, s, 0)
if ld.Iself {
} else {
ld.Diag("addgotsyminternal: unsupported binary format")
}
}
// Return the value of .TOC. for symbol s
func symtoc(s *ld.Symbol) int64 {
var toc *ld.Symbol
if s.Outer != nil {
toc = ld.Linkrlookup(ld.Ctxt, ".TOC.", int(s.Outer.Version))
} else {
toc = ld.Linkrlookup(ld.Ctxt, ".TOC.", int(s.Version))
}
if toc == nil {
ld.Diag("TOC-relative relocation in object without .TOC.")
return 0
}
return toc.Value
}
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
return -1
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
case obj.R_ADDRMIPS:
t := ld.Symaddr(r.Sym) + r.Add
if t >= 1<<32 || t < -1<<32 {
ld.Diag("program too large, address relocation = %v", t)
}
// the first instruction is always at the lower address, this is endian neutral;
// but note that o1 and o2 should still use the target endian.
o1 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off:])
o2 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off+4:])
o1 = o1&0xffff0000 | uint32(t>>16)&0xffff
o2 = o2&0xffff0000 | uint32(t)&0xffff
// when laid out, the instruction order must always be o1, o2.
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o1)<<32 | int64(o2)
} else {
*val = int64(o2)<<32 | int64(o1)
}
return 0
case obj.R_CALLMIPS,
obj.R_JMPMIPS:
// Low 26 bits = (S + A) >> 2
t := ld.Symaddr(r.Sym) + r.Add
o1 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off:])
*val = int64(o1&0xfc000000 | uint32(t>>2)&^0xfc000000)
return 0
}
return -1
}
func addgotsym(ctxt *ld.Link, s *ld.LSym) {
if s.Got >= 0 {
return
}
ld.Adddynsym(ctxt, s)
got := ld.Linklookup(ctxt, ".got", 0)
s.Got = int32(got.Size)
ld.Adduint32(ctxt, got, 0)
if ld.Iself {
rel := ld.Linklookup(ctxt, ".rel", 0)
ld.Addaddrplus(ctxt, rel, got, int64(s.Got))
ld.Adduint32(ctxt, rel, ld.ELF32_R_INFO(uint32(s.Dynid), ld.R_ARM_GLOB_DAT))
} else {
ld.Diag("addgotsym: unsupported binary format")
}
}
func addpltsym(ctxt *ld.Link, s *ld.Symbol) {
if s.Plt >= 0 {
return
}
ld.Adddynsym(ctxt, s)
if ld.Iself {
plt := ld.Linklookup(ctxt, ".plt", 0)
rela := ld.Linklookup(ctxt, ".rela.plt", 0)
if plt.Size == 0 {
elfsetupplt()
}
// Create the glink resolver if necessary
glink := ensureglinkresolver()
// Write symbol resolver stub (just a branch to the
// glink resolver stub)
r := ld.Addrel(glink)
r.Sym = glink
r.Off = int32(glink.Size)
r.Siz = 4
r.Type = obj.R_CALLPOWER
ld.Adduint32(ctxt, glink, 0x48000000) // b .glink
// In the ppc64 ABI, the dynamic linker is responsible
// for writing the entire PLT. We just need to
// reserve 8 bytes for each PLT entry and generate a
// JMP_SLOT dynamic relocation for it.
//
// TODO(austin): ABI v1 is different
s.Plt = int32(plt.Size)
plt.Size += 8
ld.Addaddrplus(ctxt, rela, plt, int64(s.Plt))
ld.Adduint64(ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_PPC64_JMP_SLOT))
ld.Adduint64(ctxt, rela, 0)
} else {
ld.Diag("addpltsym: unsupported binary format")
}
}
func addgotsym(s *ld.Symbol) {
if s.Got >= 0 {
return
}
ld.Adddynsym(ld.Ctxt, s)
got := ld.Linklookup(ld.Ctxt, ".got", 0)
s.Got = int32(got.Size)
ld.Adduint64(ld.Ctxt, got, 0)
if ld.Iself {
rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
ld.Addaddrplus(ld.Ctxt, rela, got, int64(s.Got))
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_390_GLOB_DAT))
ld.Adduint64(ld.Ctxt, rela, 0)
} else {
ld.Diag("addgotsym: unsupported binary format")
}
}
func addgotsym(ctxt *ld.Link, s *ld.Symbol) {
if s.Got >= 0 {
return
}
ld.Adddynsym(ctxt, s)
got := ld.Linklookup(ctxt, ".got", 0)
s.Got = int32(got.Size)
ld.Adduint32(ctxt, got, 0)
if ld.Iself {
rel := ld.Linklookup(ctxt, ".rel", 0)
ld.Addaddrplus(ctxt, rel, got, int64(s.Got))
ld.Adduint32(ctxt, rel, ld.ELF32_R_INFO(uint32(s.Dynid), ld.R_386_GLOB_DAT))
} else if ld.HEADTYPE == obj.Hdarwin {
ld.Adduint32(ctxt, ld.Linklookup(ctxt, ".linkedit.got", 0), uint32(s.Dynid))
} else {
ld.Diag("addgotsym: unsupported binary format")
}
}
func addgotsym(s *ld.LSym) {
if s.Got >= 0 {
return
}
ld.Adddynsym(ld.Ctxt, s)
got := ld.Linklookup(ld.Ctxt, ".got", 0)
s.Got = int32(got.Size)
ld.Adduint64(ld.Ctxt, got, 0)
if ld.Iself {
rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
ld.Addaddrplus(ld.Ctxt, rela, got, int64(s.Got))
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_X86_64_GLOB_DAT))
ld.Adduint64(ld.Ctxt, rela, 0)
} else if ld.HEADTYPE == obj.Hdarwin {
ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.got", 0), uint32(s.Dynid))
} else {
ld.Diag("addgotsym: unsupported binary format")
}
}
func addpltsym(ctxt *ld.Link, s *ld.LSym) {
if s.Plt >= 0 {
return
}
ld.Adddynsym(ctxt, s)
if ld.Iself {
plt := ld.Linklookup(ctxt, ".plt", 0)
got := ld.Linklookup(ctxt, ".got.plt", 0)
rel := ld.Linklookup(ctxt, ".rel.plt", 0)
if plt.Size == 0 {
elfsetupplt()
}
// .got entry
s.Got = int32(got.Size)
// In theory, all GOT should point to the first PLT entry,
// Linux/ARM's dynamic linker will do that for us, but FreeBSD/ARM's
// dynamic linker won't, so we'd better do it ourselves.
ld.Addaddrplus(ctxt, got, plt, 0)
// .plt entry, this depends on the .got entry
s.Plt = int32(plt.Size)
addpltreloc(ctxt, plt, got, s, obj.R_PLT0) // add lr, pc, #0xXX00000
addpltreloc(ctxt, plt, got, s, obj.R_PLT1) // add lr, lr, #0xYY000
addpltreloc(ctxt, plt, got, s, obj.R_PLT2) // ldr pc, [lr, #0xZZZ]!
// rel
ld.Addaddrplus(ctxt, rel, got, int64(s.Got))
ld.Adduint32(ctxt, rel, ld.ELF32_R_INFO(uint32(s.Dynid), ld.R_ARM_JUMP_SLOT))
} else {
ld.Diag("addpltsym: unsupported binary format")
}
}
func adddynrel(s *ld.LSym, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_386_PC32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_386_PC32 relocation for dynamic symbol %s", targ.Name)
}
if targ.Type == 0 || targ.Type == obj.SXREF {
ld.Diag("unknown symbol %s in pcrel", targ.Name)
}
r.Type = obj.R_PCREL
r.Add += 4
return
case 256 + ld.R_386_PLT32:
r.Type = obj.R_PCREL
r.Add += 4
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add += int64(targ.Plt)
}
return
case 256 + ld.R_386_GOT32, 256 + ld.R_386_GOT32X:
if targ.Type != obj.SDYNIMPORT {
// have symbol
if r.Off >= 2 && s.P[r.Off-2] == 0x8b {
// turn MOVL of GOT entry into LEAL of symbol address, relative to GOT.
s.P[r.Off-2] = 0x8d
r.Type = obj.R_GOTOFF
return
}
if r.Off >= 2 && s.P[r.Off-2] == 0xff && s.P[r.Off-1] == 0xb3 {
// turn PUSHL of GOT entry into PUSHL of symbol itself.
// use unnecessary SS prefix to keep instruction same length.
s.P[r.Off-2] = 0x36
s.P[r.Off-1] = 0x68
r.Type = obj.R_ADDR
return
}
ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
return
}
addgotsym(ld.Ctxt, targ)
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
r.Add += int64(targ.Got)
return
case 256 + ld.R_386_GOTOFF:
r.Type = obj.R_GOTOFF
return
case 256 + ld.R_386_GOTPC:
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += 4
return
case 256 + ld.R_386_32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_386_32 relocation for dynamic symbol %s", targ.Name)
}
r.Type = obj.R_ADDR
return
case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 0:
r.Type = obj.R_ADDR
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected reloc for dynamic symbol %s", targ.Name)
}
return
case 512 + ld.MACHO_GENERIC_RELOC_VANILLA*2 + 1:
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
r.Type = obj.R_PCREL
return
}
r.Type = obj.R_PCREL
return
case 512 + ld.MACHO_FAKE_GOTPCREL:
if targ.Type != obj.SDYNIMPORT {
// have symbol
// turn MOVL of GOT entry into LEAL of symbol itself
if r.Off < 2 || s.P[r.Off-2] != 0x8b {
ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
return
}
s.P[r.Off-2] = 0x8d
r.Type = obj.R_PCREL
return
}
addgotsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got)
r.Type = obj.R_PCREL
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
switch r.Type {
case obj.R_CALL,
obj.R_PCREL:
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
return
case obj.R_ADDR:
if s.Type != obj.SDATA {
break
}
if ld.Iself {
ld.Adddynsym(ld.Ctxt, targ)
rel := ld.Linklookup(ld.Ctxt, ".rel", 0)
ld.Addaddrplus(ld.Ctxt, rel, s, int64(r.Off))
ld.Adduint32(ld.Ctxt, rel, ld.ELF32_R_INFO(uint32(targ.Dynid), ld.R_386_32))
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
return
}
if ld.HEADTYPE == obj.Hdarwin && s.Size == PtrSize && r.Off == 0 {
// Mach-O relocations are a royal pain to lay out.
// They use a compact stateful bytecode representation
// that is too much bother to deal with.
// Instead, interpret the C declaration
// void *_Cvar_stderr = &stderr;
// as making _Cvar_stderr the name of a GOT entry
// for stderr. This is separate from the usual GOT entry,
// just in case the C code assigns to the variable,
// and of course it only works for single pointers,
// but we only need to support cgo and that's all it needs.
ld.Adddynsym(ld.Ctxt, targ)
got := ld.Linklookup(ld.Ctxt, ".got", 0)
s.Type = got.Type | obj.SSUB
s.Outer = got
s.Sub = got.Sub
got.Sub = s
s.Value = got.Size
ld.Adduint32(ld.Ctxt, got, 0)
ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.got", 0), uint32(targ.Dynid))
r.Type = 256 // ignore during relocsym
return
}
if ld.HEADTYPE == obj.Hwindows && s.Size == PtrSize {
// nothing to do, the relocation will be laid out in pereloc1
return
}
}
ld.Ctxt.Cursym = s
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
switch r.Type {
default:
return -1
case obj.R_ADDRARM64:
r.Done = 0
// set up addend for eventual relocation via outer symbol.
rs := r.Sym
r.Xadd = r.Add
for rs.Outer != nil {
r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
rs = rs.Outer
}
if rs.Type != obj.SHOSTOBJ && rs.Sect == nil {
ld.Diag("missing section for %s", rs.Name)
}
r.Xsym = rs
// the first instruction is always at the lower address, this is endian neutral;
// but note that o0 and o1 should still use the target endian.
o0 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off : r.Off+4])
o1 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off+4 : r.Off+8])
// Note: ld64 currently has a bug that any non-zero addend for BR26 relocation
// will make the linking fail because it thinks the code is not PIC even though
// the BR26 relocation should be fully resolved at link time.
// That is the reason why the next if block is disabled. When the bug in ld64
// is fixed, we can enable this block and also enable duff's device in cmd/7g.
if false && ld.HEADTYPE == obj.Hdarwin {
// Mach-O wants the addend to be encoded in the instruction
// Note that although Mach-O supports ARM64_RELOC_ADDEND, it
// can only encode 24-bit of signed addend, but the instructions
// supports 33-bit of signed addend, so we always encode the
// addend in place.
o0 |= (uint32((r.Xadd>>12)&3) << 29) | (uint32((r.Xadd>>12>>2)&0x7ffff) << 5)
o1 |= uint32(r.Xadd&0xfff) << 10
r.Xadd = 0
}
// when laid out, the instruction order must always be o1, o2.
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o0)<<32 | int64(o1)
} else {
*val = int64(o1)<<32 | int64(o0)
}
return 0
case obj.R_CALLARM64:
r.Done = 0
r.Xsym = r.Sym
*val = int64(0xfc000000 & uint32(r.Add))
r.Xadd = int64((uint32(r.Add) &^ 0xfc000000) * 4)
r.Add = 0
return 0
}
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
case obj.R_ADDRARM64:
t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
if t >= 1<<32 || t < -1<<32 {
ld.Diag("program too large, address relocation distance = %d", t)
}
// the first instruction is always at the lower address, this is endian neutral;
// but note that o0 and o1 should still use the target endian.
o0 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off : r.Off+4])
o1 := ld.Thelinkarch.ByteOrder.Uint32(s.P[r.Off+4 : r.Off+8])
o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
o1 |= uint32(t&0xfff) << 10
// when laid out, the instruction order must always be o1, o2.
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o0)<<32 | int64(o1)
} else {
*val = int64(o1)<<32 | int64(o0)
}
return 0
case obj.R_CALLARM64:
*val = int64((0xfc000000 & uint32(r.Add)) | uint32((ld.Symaddr(r.Sym)+r.Add*4-(s.Value+int64(r.Off)))/4))
return 0
}
return -1
}
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
switch r.Type {
case obj.R_CALLARM:
r.Done = 0
// set up addend for eventual relocation via outer symbol.
rs := r.Sym
r.Xadd = r.Add
if r.Xadd&0x800000 != 0 {
r.Xadd |= ^0xffffff
}
r.Xadd *= 4
for rs.Outer != nil {
r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
rs = rs.Outer
}
if rs.Type != obj.SHOSTOBJ && rs.Sect == nil {
ld.Diag("missing section for %s", rs.Name)
}
r.Xsym = rs
// ld64 for arm seems to want the symbol table to contain offset
// into the section rather than pseudo virtual address that contains
// the section load address.
// we need to compensate that by removing the instruction's address
// from addend.
if ld.HEADTYPE == obj.Hdarwin {
r.Xadd -= ld.Symaddr(s) + int64(r.Off)
}
*val = int64(braddoff(int32(0xff000000&uint32(r.Add)), int32(0xffffff&uint32(r.Xadd/4))))
return 0
}
return -1
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
// The following three arch specific relocations are only for generation of
// Linux/ARM ELF's PLT entry (3 assembler instruction)
case obj.R_PLT0: // add ip, pc, #0xXX00000
if ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got.plt", 0)) < ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0)) {
ld.Diag(".got.plt should be placed after .plt section.")
}
*val = 0xe28fc600 + (0xff & (int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0))+int64(r.Off))+r.Add)) >> 20))
return 0
case obj.R_PLT1: // add ip, ip, #0xYY000
*val = 0xe28cca00 + (0xff & (int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0))+int64(r.Off))+r.Add+4)) >> 12))
return 0
case obj.R_PLT2: // ldr pc, [ip, #0xZZZ]!
*val = 0xe5bcf000 + (0xfff & int64(uint32(ld.Symaddr(r.Sym)-(ld.Symaddr(ld.Linklookup(ld.Ctxt, ".plt", 0))+int64(r.Off))+r.Add+8)))
return 0
case obj.R_CALLARM: // bl XXXXXX or b YYYYYY
*val = int64(braddoff(int32(0xff000000&uint32(r.Add)), int32(0xffffff&uint32((ld.Symaddr(r.Sym)+int64((uint32(r.Add))*4)-(s.Value+int64(r.Off)))/4))))
return 0
}
return -1
}
func adddynrel(s *ld.LSym, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_ARM_PLT32:
r.Type = obj.R_CALLARM
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
}
return
case 256 + ld.R_ARM_THM_PC22: // R_ARM_THM_CALL
ld.Exitf("R_ARM_THM_CALL, are you using -marm?")
return
case 256 + ld.R_ARM_GOT32: // R_ARM_GOT_BREL
if targ.Type != obj.SDYNIMPORT {
addgotsyminternal(ld.Ctxt, targ)
} else {
addgotsym(ld.Ctxt, targ)
}
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
r.Add += int64(targ.Got)
return
case 256 + ld.R_ARM_GOT_PREL: // GOT(nil) + A - nil
if targ.Type != obj.SDYNIMPORT {
addgotsyminternal(ld.Ctxt, targ)
} else {
addgotsym(ld.Ctxt, targ)
}
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got) + 4
return
case 256 + ld.R_ARM_GOTOFF: // R_ARM_GOTOFF32
r.Type = obj.R_GOTOFF
return
case 256 + ld.R_ARM_GOTPC: // R_ARM_BASE_PREL
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += 4
return
case 256 + ld.R_ARM_CALL:
r.Type = obj.R_CALLARM
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
}
return
case 256 + ld.R_ARM_REL32: // R_ARM_REL32
r.Type = obj.R_PCREL
r.Add += 4
return
case 256 + ld.R_ARM_ABS32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_ARM_ABS32 relocation for dynamic symbol %s", targ.Name)
}
r.Type = obj.R_ADDR
return
// we can just ignore this, because we are targeting ARM V5+ anyway
case 256 + ld.R_ARM_V4BX:
if r.Sym != nil {
// R_ARM_V4BX is ABS relocation, so this symbol is a dummy symbol, ignore it
r.Sym.Type = 0
}
r.Sym = nil
return
case 256 + ld.R_ARM_PC24,
256 + ld.R_ARM_JUMP24:
r.Type = obj.R_CALLARM
if targ.Type == obj.SDYNIMPORT {
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(braddoff(int32(r.Add), targ.Plt/4))
}
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
switch r.Type {
case obj.R_CALLARM:
addpltsym(ld.Ctxt, targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
return
case obj.R_ADDR:
if s.Type != obj.SDATA {
break
}
if ld.Iself {
ld.Adddynsym(ld.Ctxt, targ)
rel := ld.Linklookup(ld.Ctxt, ".rel", 0)
ld.Addaddrplus(ld.Ctxt, rel, s, int64(r.Off))
ld.Adduint32(ld.Ctxt, rel, ld.ELF32_R_INFO(uint32(targ.Dynid), ld.R_ARM_GLOB_DAT)) // we need a nil + A dynamic reloc
r.Type = obj.R_CONST // write r->add during relocsym
r.Sym = nil
return
}
}
ld.Ctxt.Cursym = s
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
func archrelocvariant(r *ld.Reloc, s *ld.Symbol, t int64) int64 {
switch r.Variant & ld.RV_TYPE_MASK {
default:
ld.Diag("unexpected relocation variant %d", r.Variant)
fallthrough
case ld.RV_NONE:
return t
case ld.RV_POWER_LO:
if r.Variant&ld.RV_CHECK_OVERFLOW != 0 {
// Whether to check for signed or unsigned
// overflow depends on the instruction
var o1 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o1 = ld.Be32(s.P[r.Off-2:])
} else {
o1 = ld.Le32(s.P[r.Off:])
}
switch o1 >> 26 {
case 24, // ori
26, // xori
28: // andi
if t>>16 != 0 {
goto overflow
}
default:
if int64(int16(t)) != t {
goto overflow
}
}
}
return int64(int16(t))
case ld.RV_POWER_HA:
t += 0x8000
fallthrough
// Fallthrough
case ld.RV_POWER_HI:
t >>= 16
if r.Variant&ld.RV_CHECK_OVERFLOW != 0 {
// Whether to check for signed or unsigned
// overflow depends on the instruction
var o1 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o1 = ld.Be32(s.P[r.Off-2:])
} else {
o1 = ld.Le32(s.P[r.Off:])
}
switch o1 >> 26 {
case 25, // oris
27, // xoris
29: // andis
if t>>16 != 0 {
goto overflow
}
default:
if int64(int16(t)) != t {
goto overflow
}
}
}
return int64(int16(t))
case ld.RV_POWER_DS:
var o1 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o1 = uint32(ld.Be16(s.P[r.Off:]))
} else {
o1 = uint32(ld.Le16(s.P[r.Off:]))
}
if t&3 != 0 {
ld.Diag("relocation for %s+%d is not aligned: %d", r.Sym.Name, r.Off, t)
}
if (r.Variant&ld.RV_CHECK_OVERFLOW != 0) && int64(int16(t)) != t {
goto overflow
}
return int64(o1)&0x3 | int64(int16(t))
}
overflow:
ld.Diag("relocation for %s+%d is too big: %d", r.Sym.Name, r.Off, t)
return t
}
func archreloc(r *ld.Reloc, s *ld.Symbol, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
switch r.Type {
default:
return -1
case obj.R_POWER_TLS, obj.R_POWER_TLS_LE, obj.R_POWER_TLS_IE:
r.Done = 0
// check Outer is nil, Type is TLSBSS?
r.Xadd = r.Add
r.Xsym = r.Sym
return 0
case obj.R_ADDRPOWER,
obj.R_ADDRPOWER_DS,
obj.R_ADDRPOWER_TOCREL,
obj.R_ADDRPOWER_TOCREL_DS,
obj.R_ADDRPOWER_GOT,
obj.R_ADDRPOWER_PCREL:
r.Done = 0
// set up addend for eventual relocation via outer symbol.
rs := r.Sym
r.Xadd = r.Add
for rs.Outer != nil {
r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
rs = rs.Outer
}
if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
ld.Diag("missing section for %s", rs.Name)
}
r.Xsym = rs
return 0
case obj.R_CALLPOWER:
r.Done = 0
r.Xsym = r.Sym
r.Xadd = r.Add
return 0
}
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
case obj.R_ADDRPOWER, obj.R_ADDRPOWER_DS:
return archrelocaddr(r, s, val)
case obj.R_CALLPOWER:
// Bits 6 through 29 = (S + A - P) >> 2
t := ld.Symaddr(r.Sym) + r.Add - (s.Value + int64(r.Off))
if t&3 != 0 {
ld.Ctxt.Diag("relocation for %s+%d is not aligned: %d", r.Sym.Name, r.Off, t)
}
if int64(int32(t<<6)>>6) != t {
// TODO(austin) This can happen if text > 32M.
// Add a call trampoline to .text in that case.
ld.Ctxt.Diag("relocation for %s+%d is too big: %d", r.Sym.Name, r.Off, t)
}
*val |= int64(uint32(t) &^ 0xfc000003)
return 0
case obj.R_POWER_TOC: // S + A - .TOC.
*val = ld.Symaddr(r.Sym) + r.Add - symtoc(s)
return 0
case obj.R_POWER_TLS_LE:
// The thread pointer points 0x7000 bytes after the start of the the
// thread local storage area as documented in section "3.7.2 TLS
// Runtime Handling" of "Power Architecture 64-Bit ELF V2 ABI
// Specification".
v := r.Sym.Value - 0x7000
if int64(int16(v)) != v {
ld.Diag("TLS offset out of range %d", v)
}
*val = (*val &^ 0xffff) | (v & 0xffff)
return 0
}
return -1
}
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
switch r.Type {
default:
return -1
case obj.R_ADDRARM64:
r.Done = 0
// set up addend for eventual relocation via outer symbol.
rs := r.Sym
r.Xadd = r.Add
for rs.Outer != nil {
r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
rs = rs.Outer
}
if rs.Type != obj.SHOSTOBJ && rs.Sect == nil {
ld.Diag("missing section for %s", rs.Name)
}
r.Xsym = rs
// Note: ld64 currently has a bug that any non-zero addend for BR26 relocation
// will make the linking fail because it thinks the code is not PIC even though
// the BR26 relocation should be fully resolved at link time.
// That is the reason why the next if block is disabled. When the bug in ld64
// is fixed, we can enable this block and also enable duff's device in cmd/7g.
if false && ld.HEADTYPE == obj.Hdarwin {
var o0, o1 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o0 = uint32(*val >> 32)
o1 = uint32(*val)
} else {
o0 = uint32(*val)
o1 = uint32(*val >> 32)
}
// Mach-O wants the addend to be encoded in the instruction
// Note that although Mach-O supports ARM64_RELOC_ADDEND, it
// can only encode 24-bit of signed addend, but the instructions
// supports 33-bit of signed addend, so we always encode the
// addend in place.
o0 |= (uint32((r.Xadd>>12)&3) << 29) | (uint32((r.Xadd>>12>>2)&0x7ffff) << 5)
o1 |= uint32(r.Xadd&0xfff) << 10
r.Xadd = 0
// when laid out, the instruction order must always be o1, o2.
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o0)<<32 | int64(o1)
} else {
*val = int64(o1)<<32 | int64(o0)
}
}
return 0
case obj.R_CALLARM64,
obj.R_ARM64_TLS_LE,
obj.R_ARM64_TLS_IE:
r.Done = 0
r.Xsym = r.Sym
r.Xadd = r.Add
return 0
}
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
case obj.R_ADDRARM64:
t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
if t >= 1<<32 || t < -1<<32 {
ld.Diag("program too large, address relocation distance = %d", t)
}
var o0, o1 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o0 = uint32(*val >> 32)
o1 = uint32(*val)
} else {
o0 = uint32(*val)
o1 = uint32(*val >> 32)
}
o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
o1 |= uint32(t&0xfff) << 10
// when laid out, the instruction order must always be o1, o2.
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o0)<<32 | int64(o1)
} else {
*val = int64(o1)<<32 | int64(o0)
}
return 0
case obj.R_ARM64_TLS_LE:
r.Done = 0
if ld.HEADTYPE != obj.Hlinux {
ld.Diag("TLS reloc on unsupported OS %s", ld.Headstr(int(ld.HEADTYPE)))
}
// The TCB is two pointers. This is not documented anywhere, but is
// de facto part of the ABI.
v := r.Sym.Value + int64(2*ld.Thearch.Ptrsize)
if v < 0 || v >= 32678 {
ld.Diag("TLS offset out of range %d", v)
}
*val |= v << 5
return 0
case obj.R_CALLARM64:
t := (ld.Symaddr(r.Sym) + r.Add) - (s.Value + int64(r.Off))
if t >= 1<<27 || t < -1<<27 {
ld.Diag("program too large, call relocation distance = %d", t)
}
*val |= (t >> 2) & 0x03ffffff
return 0
}
return -1
}
func adddynrel(s *ld.Symbol, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_PPC64_REL24:
r.Type = obj.R_CALLPOWER
// This is a local call, so the caller isn't setting
// up r12 and r2 is the same for the caller and
// callee. Hence, we need to go to the local entry
// point. (If we don't do this, the callee will try
// to use r12 to compute r2.)
r.Add += int64(r.Sym.Localentry) * 4
if targ.Type == obj.SDYNIMPORT {
// Should have been handled in elfsetupplt
ld.Diag("unexpected R_PPC64_REL24 for dyn import")
}
return
case 256 + ld.R_PPC_REL32:
r.Type = obj.R_PCREL
r.Add += 4
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_PPC_REL32 for dyn import")
}
return
case 256 + ld.R_PPC64_ADDR64:
r.Type = obj.R_ADDR
if targ.Type == obj.SDYNIMPORT {
// These happen in .toc sections
ld.Adddynsym(ld.Ctxt, targ)
rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
ld.Addaddrplus(ld.Ctxt, rela, s, int64(r.Off))
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_PPC64_ADDR64))
ld.Adduint64(ld.Ctxt, rela, uint64(r.Add))
r.Type = 256 // ignore during relocsym
}
return
case 256 + ld.R_PPC64_TOC16:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_LO | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_LO:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_LO
return
case 256 + ld.R_PPC64_TOC16_HA:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_HA | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_HI:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_HI | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_DS:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_DS | ld.RV_CHECK_OVERFLOW
return
case 256 + ld.R_PPC64_TOC16_LO_DS:
r.Type = obj.R_POWER_TOC
r.Variant = ld.RV_POWER_DS
return
case 256 + ld.R_PPC64_REL16_LO:
r.Type = obj.R_PCREL
r.Variant = ld.RV_POWER_LO
r.Add += 2 // Compensate for relocation size of 2
return
case 256 + ld.R_PPC64_REL16_HI:
r.Type = obj.R_PCREL
r.Variant = ld.RV_POWER_HI | ld.RV_CHECK_OVERFLOW
r.Add += 2
return
case 256 + ld.R_PPC64_REL16_HA:
r.Type = obj.R_PCREL
r.Variant = ld.RV_POWER_HA | ld.RV_CHECK_OVERFLOW
r.Add += 2
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
// TODO(austin): Translate our relocations to ELF
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}
func archreloc(r *ld.Reloc, s *ld.LSym, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
switch r.Type {
default:
return -1
case obj.R_ARM64_GOTPCREL:
var o1, o2 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o1 = uint32(*val >> 32)
o2 = uint32(*val)
} else {
o1 = uint32(*val)
o2 = uint32(*val >> 32)
}
// Any relocation against a function symbol is redirected to
// be against a local symbol instead (see putelfsym in
// symtab.go) but unfortunately the system linker was buggy
// when confronted with a R_AARCH64_ADR_GOT_PAGE relocation
// against a local symbol until May 2015
// (https://sourceware.org/bugzilla/show_bug.cgi?id=18270). So
// we convert the adrp; ld64 + R_ARM64_GOTPCREL into adrp;
// add + R_ADDRARM64.
if !(r.Sym.Version != 0 || (r.Sym.Type&obj.SHIDDEN != 0) || r.Sym.Attr.Local()) && r.Sym.Type == obj.STEXT && ld.DynlinkingGo() {
if o2&0xffc00000 != 0xf9400000 {
ld.Ctxt.Diag("R_ARM64_GOTPCREL against unexpected instruction %x", o2)
}
o2 = 0x91000000 | (o2 & 0x000003ff)
r.Type = obj.R_ADDRARM64
}
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o1)<<32 | int64(o2)
} else {
*val = int64(o2)<<32 | int64(o1)
}
fallthrough
case obj.R_ADDRARM64:
r.Done = 0
// set up addend for eventual relocation via outer symbol.
rs := r.Sym
r.Xadd = r.Add
for rs.Outer != nil {
r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
rs = rs.Outer
}
if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
ld.Diag("missing section for %s", rs.Name)
}
r.Xsym = rs
// Note: ld64 currently has a bug that any non-zero addend for BR26 relocation
// will make the linking fail because it thinks the code is not PIC even though
// the BR26 relocation should be fully resolved at link time.
// That is the reason why the next if block is disabled. When the bug in ld64
// is fixed, we can enable this block and also enable duff's device in cmd/7g.
if false && ld.HEADTYPE == obj.Hdarwin {
var o0, o1 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o0 = uint32(*val >> 32)
o1 = uint32(*val)
} else {
o0 = uint32(*val)
o1 = uint32(*val >> 32)
}
// Mach-O wants the addend to be encoded in the instruction
// Note that although Mach-O supports ARM64_RELOC_ADDEND, it
// can only encode 24-bit of signed addend, but the instructions
// supports 33-bit of signed addend, so we always encode the
// addend in place.
o0 |= (uint32((r.Xadd>>12)&3) << 29) | (uint32((r.Xadd>>12>>2)&0x7ffff) << 5)
o1 |= uint32(r.Xadd&0xfff) << 10
r.Xadd = 0
// when laid out, the instruction order must always be o1, o2.
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o0)<<32 | int64(o1)
} else {
*val = int64(o1)<<32 | int64(o0)
}
}
return 0
case obj.R_CALLARM64,
obj.R_ARM64_TLS_LE,
obj.R_ARM64_TLS_IE:
r.Done = 0
r.Xsym = r.Sym
r.Xadd = r.Add
return 0
}
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
case obj.R_ADDRARM64:
t := ld.Symaddr(r.Sym) + r.Add - ((s.Value + int64(r.Off)) &^ 0xfff)
if t >= 1<<32 || t < -1<<32 {
ld.Diag("program too large, address relocation distance = %d", t)
}
var o0, o1 uint32
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
o0 = uint32(*val >> 32)
o1 = uint32(*val)
} else {
o0 = uint32(*val)
o1 = uint32(*val >> 32)
}
o0 |= (uint32((t>>12)&3) << 29) | (uint32((t>>12>>2)&0x7ffff) << 5)
o1 |= uint32(t&0xfff) << 10
// when laid out, the instruction order must always be o1, o2.
if ld.Ctxt.Arch.ByteOrder == binary.BigEndian {
*val = int64(o0)<<32 | int64(o1)
} else {
*val = int64(o1)<<32 | int64(o0)
}
return 0
case obj.R_ARM64_TLS_LE:
r.Done = 0
if ld.HEADTYPE != obj.Hlinux {
ld.Diag("TLS reloc on unsupported OS %s", ld.Headstr(int(ld.HEADTYPE)))
}
// The TCB is two pointers. This is not documented anywhere, but is
// de facto part of the ABI.
v := r.Sym.Value + int64(2*ld.Thearch.Ptrsize)
if v < 0 || v >= 32678 {
ld.Diag("TLS offset out of range %d", v)
}
*val |= v << 5
return 0
case obj.R_CALLARM64:
t := (ld.Symaddr(r.Sym) + r.Add) - (s.Value + int64(r.Off))
if t >= 1<<27 || t < -1<<27 {
ld.Diag("program too large, call relocation distance = %d", t)
}
*val |= (t >> 2) & 0x03ffffff
return 0
}
return -1
}
func machoreloc1(r *ld.Reloc, sectoff int64) int {
var v uint32
rs := r.Xsym
// ld64 has a bug handling MACHO_ARM64_RELOC_UNSIGNED with !extern relocation.
// see cmd/internal/ld/data.go for details. The workaround is that don't use !extern
// UNSIGNED relocation at all.
if rs.Type == obj.SHOSTOBJ || r.Type == obj.R_CALLARM64 || r.Type == obj.R_ADDRARM64 || r.Type == obj.R_ADDR {
if rs.Dynid < 0 {
ld.Diag("reloc %d to non-macho symbol %s type=%d", r.Type, rs.Name, rs.Type)
return -1
}
v = uint32(rs.Dynid)
v |= 1 << 27 // external relocation
} else {
v = uint32(rs.Sect.Extnum)
if v == 0 {
ld.Diag("reloc %d to symbol %s in non-macho section %s type=%d", r.Type, rs.Name, rs.Sect.Name, rs.Type)
return -1
}
}
switch r.Type {
default:
return -1
case obj.R_ADDR:
v |= ld.MACHO_ARM64_RELOC_UNSIGNED << 28
case obj.R_CALLARM64:
if r.Xadd != 0 {
ld.Diag("ld64 doesn't allow BR26 reloc with non-zero addend: %s+%d", rs.Name, r.Xadd)
}
v |= 1 << 24 // pc-relative bit
v |= ld.MACHO_ARM64_RELOC_BRANCH26 << 28
case obj.R_ADDRARM64:
r.Siz = 4
// Two relocation entries: MACHO_ARM64_RELOC_PAGEOFF12 MACHO_ARM64_RELOC_PAGE21
// if r.Xadd is non-zero, add two MACHO_ARM64_RELOC_ADDEND.
if r.Xadd != 0 {
ld.Thearch.Lput(uint32(sectoff + 4))
ld.Thearch.Lput((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
}
ld.Thearch.Lput(uint32(sectoff + 4))
ld.Thearch.Lput(v | (ld.MACHO_ARM64_RELOC_PAGEOFF12 << 28) | (2 << 25))
if r.Xadd != 0 {
ld.Thearch.Lput(uint32(sectoff))
ld.Thearch.Lput((ld.MACHO_ARM64_RELOC_ADDEND << 28) | (2 << 25) | uint32(r.Xadd&0xffffff))
}
v |= 1 << 24 // pc-relative bit
v |= ld.MACHO_ARM64_RELOC_PAGE21 << 28
}
switch r.Siz {
default:
return -1
case 1:
v |= 0 << 25
case 2:
v |= 1 << 25
case 4:
v |= 2 << 25
case 8:
v |= 3 << 25
}
ld.Thearch.Lput(uint32(sectoff))
ld.Thearch.Lput(v)
return 0
}
func asmb() {
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f asmb\n", obj.Cputime())
}
ld.Bso.Flush()
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f codeblk\n", obj.Cputime())
}
ld.Bso.Flush()
if ld.Iself {
ld.Asmbelfsetup()
}
sect := ld.Segtext.Sect
ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
ld.Codeblk(int64(sect.Vaddr), int64(sect.Length))
for sect = sect.Next; sect != nil; sect = sect.Next {
ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff))
ld.Datblk(int64(sect.Vaddr), int64(sect.Length))
}
if ld.Segrodata.Filelen > 0 {
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f rodatblk\n", obj.Cputime())
}
ld.Bso.Flush()
ld.Cseek(int64(ld.Segrodata.Fileoff))
ld.Datblk(int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen))
}
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f datblk\n", obj.Cputime())
}
ld.Bso.Flush()
ld.Cseek(int64(ld.Segdata.Fileoff))
ld.Datblk(int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen))
machlink := int64(0)
if ld.HEADTYPE == obj.Hdarwin {
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f dwarf\n", obj.Cputime())
}
dwarfoff := ld.Rnd(int64(uint64(ld.HEADR)+ld.Segtext.Length), int64(ld.INITRND)) + ld.Rnd(int64(ld.Segdata.Filelen), int64(ld.INITRND))
ld.Cseek(dwarfoff)
ld.Segdwarf.Fileoff = uint64(ld.Cpos())
ld.Dwarfemitdebugsections()
ld.Segdwarf.Filelen = uint64(ld.Cpos()) - ld.Segdwarf.Fileoff
machlink = ld.Domacholink()
}
switch ld.HEADTYPE {
default:
ld.Diag("unknown header type %d", ld.HEADTYPE)
fallthrough
case obj.Hplan9,
obj.Helf:
break
case obj.Hdarwin:
ld.Debug['8'] = 1 /* 64-bit addresses */
case obj.Hlinux,
obj.Hfreebsd,
obj.Hnetbsd,
obj.Hopenbsd,
obj.Hdragonfly,
obj.Hsolaris:
ld.Debug['8'] = 1 /* 64-bit addresses */
case obj.Hnacl,
obj.Hwindows:
break
}
ld.Symsize = 0
ld.Spsize = 0
ld.Lcsize = 0
symo := int64(0)
if ld.Debug['s'] == 0 {
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f sym\n", obj.Cputime())
}
ld.Bso.Flush()
switch ld.HEADTYPE {
default:
case obj.Hplan9,
obj.Helf:
ld.Debug['s'] = 1
symo = int64(ld.Segdata.Fileoff + ld.Segdata.Filelen)
case obj.Hdarwin:
symo = int64(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(ld.INITRND))) + uint64(machlink))
case obj.Hlinux,
obj.Hfreebsd,
obj.Hnetbsd,
obj.Hopenbsd,
obj.Hdragonfly,
obj.Hsolaris,
obj.Hnacl:
symo = int64(ld.Segdata.Fileoff + ld.Segdata.Filelen)
symo = ld.Rnd(symo, int64(ld.INITRND))
case obj.Hwindows:
symo = int64(ld.Segdata.Fileoff + ld.Segdata.Filelen)
symo = ld.Rnd(symo, ld.PEFILEALIGN)
}
ld.Cseek(symo)
switch ld.HEADTYPE {
default:
if ld.Iself {
ld.Cseek(symo)
ld.Asmelfsym()
ld.Cflush()
ld.Cwrite(ld.Elfstrdat)
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f dwarf\n", obj.Cputime())
}
ld.Dwarfemitdebugsections()
if ld.Linkmode == ld.LinkExternal {
ld.Elfemitreloc()
}
}
case obj.Hplan9:
ld.Asmplan9sym()
ld.Cflush()
sym := ld.Linklookup(ld.Ctxt, "pclntab", 0)
if sym != nil {
ld.Lcsize = int32(len(sym.P))
for i := 0; int32(i) < ld.Lcsize; i++ {
ld.Cput(uint8(sym.P[i]))
}
ld.Cflush()
}
case obj.Hwindows:
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f dwarf\n", obj.Cputime())
}
ld.Dwarfemitdebugsections()
case obj.Hdarwin:
if ld.Linkmode == ld.LinkExternal {
ld.Machoemitreloc()
}
}
}
if ld.Debug['v'] != 0 {
fmt.Fprintf(&ld.Bso, "%5.2f headr\n", obj.Cputime())
}
ld.Bso.Flush()
ld.Cseek(0)
switch ld.HEADTYPE {
default:
case obj.Hplan9: /* plan9 */
magic := int32(4*26*26 + 7)
magic |= 0x00008000 /* fat header */
ld.Lputb(uint32(magic)) /* magic */
ld.Lputb(uint32(ld.Segtext.Filelen)) /* sizes */
ld.Lputb(uint32(ld.Segdata.Filelen))
ld.Lputb(uint32(ld.Segdata.Length - ld.Segdata.Filelen))
ld.Lputb(uint32(ld.Symsize)) /* nsyms */
vl := ld.Entryvalue()
ld.Lputb(PADDR(uint32(vl))) /* va of entry */
ld.Lputb(uint32(ld.Spsize)) /* sp offsets */
ld.Lputb(uint32(ld.Lcsize)) /* line offsets */
ld.Vputb(uint64(vl)) /* va of entry */
case obj.Hdarwin:
ld.Asmbmacho()
case obj.Hlinux,
obj.Hfreebsd,
obj.Hnetbsd,
obj.Hopenbsd,
obj.Hdragonfly,
obj.Hsolaris,
obj.Hnacl:
ld.Asmbelf(symo)
case obj.Hwindows:
ld.Asmbpe()
}
ld.Cflush()
}
func addpltsym(s *ld.LSym) {
if s.Plt >= 0 {
return
}
ld.Adddynsym(ld.Ctxt, s)
if ld.Iself {
plt := ld.Linklookup(ld.Ctxt, ".plt", 0)
got := ld.Linklookup(ld.Ctxt, ".got.plt", 0)
rela := ld.Linklookup(ld.Ctxt, ".rela.plt", 0)
if plt.Size == 0 {
elfsetupplt()
}
// jmpq *got+size(IP)
ld.Adduint8(ld.Ctxt, plt, 0xff)
ld.Adduint8(ld.Ctxt, plt, 0x25)
ld.Addpcrelplus(ld.Ctxt, plt, got, got.Size)
// add to got: pointer to current pos in plt
ld.Addaddrplus(ld.Ctxt, got, plt, plt.Size)
// pushq $x
ld.Adduint8(ld.Ctxt, plt, 0x68)
ld.Adduint32(ld.Ctxt, plt, uint32((got.Size-24-8)/8))
// jmpq .plt
ld.Adduint8(ld.Ctxt, plt, 0xe9)
ld.Adduint32(ld.Ctxt, plt, uint32(-(plt.Size + 4)))
// rela
ld.Addaddrplus(ld.Ctxt, rela, got, got.Size-8)
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_X86_64_JMP_SLOT))
ld.Adduint64(ld.Ctxt, rela, 0)
s.Plt = int32(plt.Size - 16)
} else if ld.HEADTYPE == obj.Hdarwin {
// To do lazy symbol lookup right, we're supposed
// to tell the dynamic loader which library each
// symbol comes from and format the link info
// section just so. I'm too lazy (ha!) to do that
// so for now we'll just use non-lazy pointers,
// which don't need to be told which library to use.
//
// http://networkpx.blogspot.com/2009/09/about-lcdyldinfoonly-command.html
// has details about what we're avoiding.
addgotsym(s)
plt := ld.Linklookup(ld.Ctxt, ".plt", 0)
ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.plt", 0), uint32(s.Dynid))
// jmpq *got+size(IP)
s.Plt = int32(plt.Size)
ld.Adduint8(ld.Ctxt, plt, 0xff)
ld.Adduint8(ld.Ctxt, plt, 0x25)
ld.Addpcrelplus(ld.Ctxt, plt, ld.Linklookup(ld.Ctxt, ".got", 0), int64(s.Got))
} else {
ld.Diag("addpltsym: unsupported binary format")
}
}
func archreloc(r *ld.Reloc, s *ld.Symbol, val *int64) int {
if ld.Linkmode == ld.LinkExternal {
switch r.Type {
default:
return -1
case obj.R_ADDRMIPS,
obj.R_ADDRMIPSU:
r.Done = 0
// set up addend for eventual relocation via outer symbol.
rs := r.Sym
r.Xadd = r.Add
for rs.Outer != nil {
r.Xadd += ld.Symaddr(rs) - ld.Symaddr(rs.Outer)
rs = rs.Outer
}
if rs.Type != obj.SHOSTOBJ && rs.Type != obj.SDYNIMPORT && rs.Sect == nil {
ld.Diag("missing section for %s", rs.Name)
}
r.Xsym = rs
return 0
case obj.R_ADDRMIPSTLS,
obj.R_CALLMIPS,
obj.R_JMPMIPS:
r.Done = 0
r.Xsym = r.Sym
r.Xadd = r.Add
return 0
}
}
switch r.Type {
case obj.R_CONST:
*val = r.Add
return 0
case obj.R_GOTOFF:
*val = ld.Symaddr(r.Sym) + r.Add - ld.Symaddr(ld.Linklookup(ld.Ctxt, ".got", 0))
return 0
case obj.R_ADDRMIPS,
obj.R_ADDRMIPSU:
t := ld.Symaddr(r.Sym) + r.Add
o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
if r.Type == obj.R_ADDRMIPS {
*val = int64(o1&0xffff0000 | uint32(t)&0xffff)
} else {
*val = int64(o1&0xffff0000 | uint32((t+1<<15)>>16)&0xffff)
}
return 0
case obj.R_ADDRMIPSTLS:
// thread pointer is at 0x7000 offset from the start of TLS data area
t := ld.Symaddr(r.Sym) + r.Add - 0x7000
if t < -32768 || t >= 32678 {
ld.Diag("TLS offset out of range %d", t)
}
o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
*val = int64(o1&0xffff0000 | uint32(t)&0xffff)
return 0
case obj.R_CALLMIPS,
obj.R_JMPMIPS:
// Low 26 bits = (S + A) >> 2
t := ld.Symaddr(r.Sym) + r.Add
o1 := ld.SysArch.ByteOrder.Uint32(s.P[r.Off:])
*val = int64(o1&0xfc000000 | uint32(t>>2)&^0xfc000000)
return 0
}
return -1
}
func adddynrel(s *ld.LSym, r *ld.Reloc) {
targ := r.Sym
ld.Ctxt.Cursym = s
switch r.Type {
default:
if r.Type >= 256 {
ld.Diag("unexpected relocation type %d", r.Type)
return
}
// Handle relocations found in ELF object files.
case 256 + ld.R_X86_64_PC32:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_X86_64_PC32 relocation for dynamic symbol %s", targ.Name)
}
if targ.Type == 0 || targ.Type == obj.SXREF {
ld.Diag("unknown symbol %s in pcrel", targ.Name)
}
r.Type = obj.R_PCREL
r.Add += 4
return
case 256 + ld.R_X86_64_PLT32:
r.Type = obj.R_PCREL
r.Add += 4
if targ.Type == obj.SDYNIMPORT {
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add += int64(targ.Plt)
}
return
case 256 + ld.R_X86_64_GOTPCREL, 256 + ld.R_X86_64_GOTPCRELX, 256 + ld.R_X86_64_REX_GOTPCRELX:
if targ.Type != obj.SDYNIMPORT {
// have symbol
if r.Off >= 2 && s.P[r.Off-2] == 0x8b {
// turn MOVQ of GOT entry into LEAQ of symbol itself
s.P[r.Off-2] = 0x8d
r.Type = obj.R_PCREL
r.Add += 4
return
}
}
// fall back to using GOT and hope for the best (CMOV*)
// TODO: just needs relocation, no need to put in .dynsym
addgotsym(targ)
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += 4
r.Add += int64(targ.Got)
return
case 256 + ld.R_X86_64_64:
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected R_X86_64_64 relocation for dynamic symbol %s", targ.Name)
}
r.Type = obj.R_ADDR
return
// Handle relocations found in Mach-O object files.
case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 0,
512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 0,
512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 0:
// TODO: What is the difference between all these?
r.Type = obj.R_ADDR
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected reloc for dynamic symbol %s", targ.Name)
}
return
case 512 + ld.MACHO_X86_64_RELOC_BRANCH*2 + 1:
if targ.Type == obj.SDYNIMPORT {
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
r.Type = obj.R_PCREL
return
}
fallthrough
// fall through
case 512 + ld.MACHO_X86_64_RELOC_UNSIGNED*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED_1*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED_2*2 + 1,
512 + ld.MACHO_X86_64_RELOC_SIGNED_4*2 + 1:
r.Type = obj.R_PCREL
if targ.Type == obj.SDYNIMPORT {
ld.Diag("unexpected pc-relative reloc for dynamic symbol %s", targ.Name)
}
return
case 512 + ld.MACHO_X86_64_RELOC_GOT_LOAD*2 + 1:
if targ.Type != obj.SDYNIMPORT {
// have symbol
// turn MOVQ of GOT entry into LEAQ of symbol itself
if r.Off < 2 || s.P[r.Off-2] != 0x8b {
ld.Diag("unexpected GOT_LOAD reloc for non-dynamic symbol %s", targ.Name)
return
}
s.P[r.Off-2] = 0x8d
r.Type = obj.R_PCREL
return
}
fallthrough
// fall through
case 512 + ld.MACHO_X86_64_RELOC_GOT*2 + 1:
if targ.Type != obj.SDYNIMPORT {
ld.Diag("unexpected GOT reloc for non-dynamic symbol %s", targ.Name)
}
addgotsym(targ)
r.Type = obj.R_PCREL
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got)
return
}
// Handle references to ELF symbols from our own object files.
if targ.Type != obj.SDYNIMPORT {
return
}
switch r.Type {
case obj.R_CALL,
obj.R_PCREL:
if ld.HEADTYPE == obj.Hwindows {
// nothing to do, the relocation will be laid out in pereloc1
return
} else {
// for both ELF and Mach-O
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add = int64(targ.Plt)
return
}
case obj.R_ADDR:
if s.Type == obj.STEXT && ld.Iself {
if ld.HEADTYPE == obj.Hsolaris {
addpltsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".plt", 0)
r.Add += int64(targ.Plt)
return
}
// The code is asking for the address of an external
// function. We provide it with the address of the
// correspondent GOT symbol.
addgotsym(targ)
r.Sym = ld.Linklookup(ld.Ctxt, ".got", 0)
r.Add += int64(targ.Got)
return
}
if s.Type != obj.SDATA {
break
}
if ld.Iself {
ld.Adddynsym(ld.Ctxt, targ)
rela := ld.Linklookup(ld.Ctxt, ".rela", 0)
ld.Addaddrplus(ld.Ctxt, rela, s, int64(r.Off))
if r.Siz == 8 {
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_X86_64_64))
} else {
ld.Adduint64(ld.Ctxt, rela, ld.ELF64_R_INFO(uint32(targ.Dynid), ld.R_X86_64_32))
}
ld.Adduint64(ld.Ctxt, rela, uint64(r.Add))
r.Type = 256 // ignore during relocsym
return
}
if ld.HEADTYPE == obj.Hdarwin && s.Size == int64(ld.Thearch.Ptrsize) && r.Off == 0 {
// Mach-O relocations are a royal pain to lay out.
// They use a compact stateful bytecode representation
// that is too much bother to deal with.
// Instead, interpret the C declaration
// void *_Cvar_stderr = &stderr;
// as making _Cvar_stderr the name of a GOT entry
// for stderr. This is separate from the usual GOT entry,
// just in case the C code assigns to the variable,
// and of course it only works for single pointers,
// but we only need to support cgo and that's all it needs.
ld.Adddynsym(ld.Ctxt, targ)
got := ld.Linklookup(ld.Ctxt, ".got", 0)
s.Type = got.Type | obj.SSUB
s.Outer = got
s.Sub = got.Sub
got.Sub = s
s.Value = got.Size
ld.Adduint64(ld.Ctxt, got, 0)
ld.Adduint32(ld.Ctxt, ld.Linklookup(ld.Ctxt, ".linkedit.got", 0), uint32(targ.Dynid))
r.Type = 256 // ignore during relocsym
return
}
if ld.HEADTYPE == obj.Hwindows {
// nothing to do, the relocation will be laid out in pereloc1
return
}
}
ld.Ctxt.Cursym = s
ld.Diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ.Name, r.Type, targ.Type)
}