Esempio n. 1
0
File: asm.go Progetto: achanda/go
func elfsetupplt(ctxt *ld.Link) {
	plt := ctxt.Syms.Lookup(".plt", 0)
	got := ctxt.Syms.Lookup(".got.plt", 0)
	if plt.Size == 0 {
		// pushl got+4
		ld.Adduint8(ctxt, plt, 0xff)

		ld.Adduint8(ctxt, plt, 0x35)
		ld.Addaddrplus(ctxt, plt, got, 4)

		// jmp *got+8
		ld.Adduint8(ctxt, plt, 0xff)

		ld.Adduint8(ctxt, plt, 0x25)
		ld.Addaddrplus(ctxt, plt, got, 8)

		// zero pad
		ld.Adduint32(ctxt, plt, 0)

		// assume got->size == 0 too
		ld.Addaddrplus(ctxt, got, ctxt.Syms.Lookup(".dynamic", 0), 0)

		ld.Adduint32(ctxt, got, 0)
		ld.Adduint32(ctxt, got, 0)
	}
}
Esempio n. 2
0
func elfsetupplt() {
	plt := ld.Linklookup(ld.Ctxt, ".plt", 0)
	got := ld.Linklookup(ld.Ctxt, ".got.plt", 0)
	if plt.Size == 0 {
		// pushl got+4
		ld.Adduint8(ld.Ctxt, plt, 0xff)

		ld.Adduint8(ld.Ctxt, plt, 0x35)
		ld.Addaddrplus(ld.Ctxt, plt, got, 4)

		// jmp *got+8
		ld.Adduint8(ld.Ctxt, plt, 0xff)

		ld.Adduint8(ld.Ctxt, plt, 0x25)
		ld.Addaddrplus(ld.Ctxt, plt, got, 8)

		// zero pad
		ld.Adduint32(ld.Ctxt, plt, 0)

		// assume got->size == 0 too
		ld.Addaddrplus(ld.Ctxt, got, ld.Linklookup(ld.Ctxt, ".dynamic", 0), 0)

		ld.Adduint32(ld.Ctxt, got, 0)
		ld.Adduint32(ld.Ctxt, got, 0)
	}
}
Esempio n. 3
0
File: asm.go Progetto: sreis/go
func elfsetupplt() {
	plt := ld.Linklookup(ld.Ctxt, ".plt", 0)
	got := ld.Linklookup(ld.Ctxt, ".got.plt", 0)
	if plt.Size == 0 {
		// pushq got+8(IP)
		ld.Adduint8(ld.Ctxt, plt, 0xff)

		ld.Adduint8(ld.Ctxt, plt, 0x35)
		ld.Addpcrelplus(ld.Ctxt, plt, got, 8)

		// jmpq got+16(IP)
		ld.Adduint8(ld.Ctxt, plt, 0xff)

		ld.Adduint8(ld.Ctxt, plt, 0x25)
		ld.Addpcrelplus(ld.Ctxt, plt, got, 16)

		// nopl 0(AX)
		ld.Adduint32(ld.Ctxt, plt, 0x00401f0f)

		// assume got->size == 0 too
		ld.Addaddrplus(ld.Ctxt, got, ld.Linklookup(ld.Ctxt, ".dynamic", 0), 0)

		ld.Adduint64(ld.Ctxt, got, 0)
		ld.Adduint64(ld.Ctxt, got, 0)
	}
}
Esempio n. 4
0
File: asm.go Progetto: hurkgu/go
// gentext generates assembly to append the local moduledata to the global
// moduledata linked list at initialization time. This is only done if the runtime
// is in a different module.
//
// <go.link.addmoduledata>:
// 	larl  %r2, <local.moduledata>
// 	jg    <runtime.addmoduledata@plt>
//	undef
//
// The job of appending the moduledata is delegated to runtime.addmoduledata.
func gentext(ctxt *ld.Link) {
	if !ld.DynlinkingGo() {
		return
	}
	addmoduledata := ld.Linklookup(ctxt, "runtime.addmoduledata", 0)
	if addmoduledata.Type == obj.STEXT {
		// we're linking a module containing the runtime -> no need for
		// an init function
		return
	}
	addmoduledata.Attr |= ld.AttrReachable
	initfunc := ld.Linklookup(ctxt, "go.link.addmoduledata", 0)
	initfunc.Type = obj.STEXT
	initfunc.Attr |= ld.AttrLocal
	initfunc.Attr |= ld.AttrReachable

	// larl %r2, <local.moduledata>
	ld.Adduint8(ctxt, initfunc, 0xc0)
	ld.Adduint8(ctxt, initfunc, 0x20)
	lmd := ld.Addrel(initfunc)
	lmd.Off = int32(initfunc.Size)
	lmd.Siz = 4
	lmd.Sym = ctxt.Moduledata
	lmd.Type = obj.R_PCREL
	lmd.Variant = ld.RV_390_DBL
	lmd.Add = 2 + int64(lmd.Siz)
	ld.Adduint32(ctxt, initfunc, 0)

	// jg <runtime.addmoduledata[@plt]>
	ld.Adduint8(ctxt, initfunc, 0xc0)
	ld.Adduint8(ctxt, initfunc, 0xf4)
	rel := ld.Addrel(initfunc)
	rel.Off = int32(initfunc.Size)
	rel.Siz = 4
	rel.Sym = ld.Linklookup(ctxt, "runtime.addmoduledata", 0)
	rel.Type = obj.R_CALL
	rel.Variant = ld.RV_390_DBL
	rel.Add = 2 + int64(rel.Siz)
	ld.Adduint32(ctxt, initfunc, 0)

	// undef (for debugging)
	ld.Adduint32(ctxt, initfunc, 0)

	ctxt.Textp = append(ctxt.Textp, initfunc)
	initarray_entry := ld.Linklookup(ctxt, "go.link.addmoduledatainit", 0)
	initarray_entry.Attr |= ld.AttrLocal
	initarray_entry.Attr |= ld.AttrReachable
	initarray_entry.Type = obj.SINITARR
	ld.Addaddr(ctxt, initarray_entry, initfunc)
}
Esempio n. 5
0
func gentext() {
	if !ld.DynlinkingGo() && ld.Buildmode != ld.BuildmodePIE {
		return
	}

	thunkfunc := ld.Linklookup(ld.Ctxt, "__x86.get_pc_thunk.cx", 0)
	thunkfunc.Type = obj.STEXT
	thunkfunc.Local = true
	thunkfunc.Reachable = true
	o := func(op ...uint8) {
		for _, op1 := range op {
			ld.Adduint8(ld.Ctxt, thunkfunc, op1)
		}
	}
	// 8b 0c 24	mov    (%esp),%ecx
	o(0x8b, 0x0c, 0x24)
	// c3		ret
	o(0xc3)

	if ld.Ctxt.Etextp != nil {
		ld.Ctxt.Etextp.Next = thunkfunc
	} else {
		ld.Ctxt.Textp = thunkfunc
	}
	ld.Ctxt.Etextp = thunkfunc
}
Esempio n. 6
0
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")
	}
}
Esempio n. 7
0
File: asm.go Progetto: sreis/go
func gentext() {
	if !ld.DynlinkingGo() {
		return
	}
	addmoduledata := ld.Linklookup(ld.Ctxt, "runtime.addmoduledata", 0)
	if addmoduledata.Type == obj.STEXT {
		// we're linking a module containing the runtime -> no need for
		// an init function
		return
	}
	addmoduledata.Reachable = true
	initfunc := ld.Linklookup(ld.Ctxt, "go.link.addmoduledata", 0)
	initfunc.Type = obj.STEXT
	initfunc.Local = true
	initfunc.Reachable = true
	o := func(op ...uint8) {
		for _, op1 := range op {
			ld.Adduint8(ld.Ctxt, initfunc, op1)
		}
	}
	// 0000000000000000 <local.dso_init>:
	//    0:	48 8d 3d 00 00 00 00 	lea    0x0(%rip),%rdi        # 7 <local.dso_init+0x7>
	// 			3: R_X86_64_PC32	runtime.firstmoduledata-0x4
	o(0x48, 0x8d, 0x3d)
	ld.Addpcrelplus(ld.Ctxt, initfunc, ld.Ctxt.Moduledata, 0)
	//    7:	e8 00 00 00 00       	callq  c <local.dso_init+0xc>
	// 			8: R_X86_64_PLT32	runtime.addmoduledata-0x4
	o(0xe8)
	Addcall(ld.Ctxt, initfunc, addmoduledata)
	//    c:	c3                   	retq
	o(0xc3)
	if ld.Ctxt.Etextp != nil {
		ld.Ctxt.Etextp.Next = initfunc
	} else {
		ld.Ctxt.Textp = initfunc
	}
	ld.Ctxt.Etextp = initfunc
	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
	initarray_entry.Reachable = true
	initarray_entry.Local = true
	initarray_entry.Type = obj.SINITARR
	ld.Addaddr(ld.Ctxt, initarray_entry, initfunc)
}
Esempio n. 8
0
File: asm.go Progetto: achanda/go
func gentext(ctxt *ld.Link) {
	if !ctxt.DynlinkingGo() {
		return
	}
	addmoduledata := ctxt.Syms.Lookup("runtime.addmoduledata", 0)
	if addmoduledata.Type == obj.STEXT && ld.Buildmode != ld.BuildmodePlugin {
		// we're linking a module containing the runtime -> no need for
		// an init function
		return
	}
	addmoduledata.Attr |= ld.AttrReachable
	initfunc := ctxt.Syms.Lookup("go.link.addmoduledata", 0)
	initfunc.Type = obj.STEXT
	initfunc.Attr |= ld.AttrLocal
	initfunc.Attr |= ld.AttrReachable
	o := func(op ...uint8) {
		for _, op1 := range op {
			ld.Adduint8(ctxt, initfunc, op1)
		}
	}
	// 0000000000000000 <local.dso_init>:
	//    0:	48 8d 3d 00 00 00 00 	lea    0x0(%rip),%rdi        # 7 <local.dso_init+0x7>
	// 			3: R_X86_64_PC32	runtime.firstmoduledata-0x4
	o(0x48, 0x8d, 0x3d)
	ld.Addpcrelplus(ctxt, initfunc, ctxt.Moduledata, 0)
	//    7:	e8 00 00 00 00       	callq  c <local.dso_init+0xc>
	// 			8: R_X86_64_PLT32	runtime.addmoduledata-0x4
	o(0xe8)
	Addcall(ctxt, initfunc, addmoduledata)
	//    c:	c3                   	retq
	o(0xc3)
	if ld.Buildmode == ld.BuildmodePlugin {
		ctxt.Textp = append(ctxt.Textp, addmoduledata)
	}
	ctxt.Textp = append(ctxt.Textp, initfunc)
	initarray_entry := ctxt.Syms.Lookup("go.link.addmoduledatainit", 0)
	initarray_entry.Attr |= ld.AttrReachable
	initarray_entry.Attr |= ld.AttrLocal
	initarray_entry.Type = obj.SINITARR
	ld.Addaddr(ctxt, initarray_entry, initfunc)
}
Esempio n. 9
0
File: asm.go Progetto: sreis/go
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")
	}
}
Esempio n. 10
0
File: asm.go Progetto: sreis/go
func gentext() {
	if !ld.DynlinkingGo() && ld.Buildmode != ld.BuildmodePIE && ld.Buildmode != ld.BuildmodeCShared {
		return
	}

	thunkfunc := ld.Linklookup(ld.Ctxt, "__x86.get_pc_thunk.cx", 0)
	thunkfunc.Type = obj.STEXT
	thunkfunc.Local = true
	thunkfunc.Reachable = true
	o := func(op ...uint8) {
		for _, op1 := range op {
			ld.Adduint8(ld.Ctxt, thunkfunc, op1)
		}
	}
	// 8b 0c 24	mov    (%esp),%ecx
	o(0x8b, 0x0c, 0x24)
	// c3		ret
	o(0xc3)

	if ld.Ctxt.Etextp != nil {
		ld.Ctxt.Etextp.Next = thunkfunc
	} else {
		ld.Ctxt.Textp = thunkfunc
	}
	ld.Ctxt.Etextp = thunkfunc

	addmoduledata := ld.Linklookup(ld.Ctxt, "runtime.addmoduledata", 0)
	if addmoduledata.Type == obj.STEXT {
		// we're linking a module containing the runtime -> no need for
		// an init function
		return
	}

	addmoduledata.Reachable = true

	initfunc := ld.Linklookup(ld.Ctxt, "go.link.addmoduledata", 0)
	initfunc.Type = obj.STEXT
	initfunc.Local = true
	initfunc.Reachable = true
	o = func(op ...uint8) {
		for _, op1 := range op {
			ld.Adduint8(ld.Ctxt, initfunc, op1)
		}
	}

	// go.link.addmoduledata:
	//      53                      push %ebx
	//      e8 00 00 00 00          call __x86.get_pc_thunk.cx + R_CALL __x86.get_pc_thunk.cx
	//      8d 81 00 00 00 00       lea 0x0(%ecx), %eax + R_PCREL ld.Ctxt.Moduledata
	//      8d 99 00 00 00 00       lea 0x0(%ecx), %ebx + R_GOTPC _GLOBAL_OFFSET_TABLE_
	//      e8 00 00 00 00          call runtime.addmoduledata@plt + R_CALL runtime.addmoduledata
	//      5b                      pop %ebx
	//      c3                      ret

	o(0x53)

	o(0xe8)
	addcall(ld.Ctxt, initfunc, ld.Linklookup(ld.Ctxt, "__x86.get_pc_thunk.cx", 0))

	o(0x8d, 0x81)
	ld.Addpcrelplus(ld.Ctxt, initfunc, ld.Ctxt.Moduledata, 6)

	o(0x8d, 0x99)
	i := initfunc.Size
	initfunc.Size += 4
	ld.Symgrow(ld.Ctxt, initfunc, initfunc.Size)
	r := ld.Addrel(initfunc)
	r.Sym = ld.Linklookup(ld.Ctxt, "_GLOBAL_OFFSET_TABLE_", 0)
	r.Off = int32(i)
	r.Type = obj.R_PCREL
	r.Add = 12
	r.Siz = 4

	o(0xe8)
	addcall(ld.Ctxt, initfunc, addmoduledata)

	o(0x5b)

	o(0xc3)

	ld.Ctxt.Etextp.Next = initfunc
	ld.Ctxt.Etextp = initfunc
	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
	initarray_entry.Reachable = true
	initarray_entry.Local = true
	initarray_entry.Type = obj.SINITARR
	ld.Addaddr(ld.Ctxt, initarray_entry, initfunc)
}
Esempio n. 11
0
File: asm.go Progetto: SpiderOak/go
func gentext(ctxt *ld.Link) {
	if !ld.DynlinkingGo() && ld.Buildmode != ld.BuildmodePIE && ld.Buildmode != ld.BuildmodeCShared {
		return
	}

	// Generate little thunks that load the PC of the next instruction into a register.
	for _, r := range [...]struct {
		name string
		num  uint8
	}{
		{"ax", 0},
		{"cx", 1},
		{"dx", 2},
		{"bx", 3},
		// sp
		{"bp", 5},
		{"si", 6},
		{"di", 7},
	} {
		thunkfunc := ld.Linklookup(ctxt, "__x86.get_pc_thunk."+r.name, 0)
		thunkfunc.Type = obj.STEXT
		thunkfunc.Attr |= ld.AttrLocal
		thunkfunc.Attr |= ld.AttrReachable //TODO: remove?
		o := func(op ...uint8) {
			for _, op1 := range op {
				ld.Adduint8(ctxt, thunkfunc, op1)
			}
		}
		// 8b 04 24	mov    (%esp),%eax
		// Destination register is in bits 3-5 of the middle byte, so add that in.
		o(0x8b, 0x04+r.num<<3, 0x24)
		// c3		ret
		o(0xc3)

		ctxt.Textp = append(ctxt.Textp, thunkfunc)
	}

	addmoduledata := ld.Linklookup(ctxt, "runtime.addmoduledata", 0)
	if addmoduledata.Type == obj.STEXT {
		// we're linking a module containing the runtime -> no need for
		// an init function
		return
	}

	addmoduledata.Attr |= ld.AttrReachable

	initfunc := ld.Linklookup(ctxt, "go.link.addmoduledata", 0)
	initfunc.Type = obj.STEXT
	initfunc.Attr |= ld.AttrLocal
	initfunc.Attr |= ld.AttrReachable
	o := func(op ...uint8) {
		for _, op1 := range op {
			ld.Adduint8(ctxt, initfunc, op1)
		}
	}

	// go.link.addmoduledata:
	//      53                      push %ebx
	//      e8 00 00 00 00          call __x86.get_pc_thunk.cx + R_CALL __x86.get_pc_thunk.cx
	//      8d 81 00 00 00 00       lea 0x0(%ecx), %eax + R_PCREL ctxt.Moduledata
	//      8d 99 00 00 00 00       lea 0x0(%ecx), %ebx + R_GOTPC _GLOBAL_OFFSET_TABLE_
	//      e8 00 00 00 00          call runtime.addmoduledata@plt + R_CALL runtime.addmoduledata
	//      5b                      pop %ebx
	//      c3                      ret

	o(0x53)

	o(0xe8)
	addcall(ctxt, initfunc, ld.Linklookup(ctxt, "__x86.get_pc_thunk.cx", 0))

	o(0x8d, 0x81)
	ld.Addpcrelplus(ctxt, initfunc, ctxt.Moduledata, 6)

	o(0x8d, 0x99)
	i := initfunc.Size
	initfunc.Size += 4
	ld.Symgrow(ctxt, initfunc, initfunc.Size)
	r := ld.Addrel(initfunc)
	r.Sym = ld.Linklookup(ctxt, "_GLOBAL_OFFSET_TABLE_", 0)
	r.Off = int32(i)
	r.Type = obj.R_PCREL
	r.Add = 12
	r.Siz = 4

	o(0xe8)
	addcall(ctxt, initfunc, addmoduledata)

	o(0x5b)

	o(0xc3)

	ctxt.Textp = append(ctxt.Textp, initfunc)
	initarray_entry := ld.Linklookup(ctxt, "go.link.addmoduledatainit", 0)
	initarray_entry.Attr |= ld.AttrReachable
	initarray_entry.Attr |= ld.AttrLocal
	initarray_entry.Type = obj.SINITARR
	ld.Addaddr(ctxt, initarray_entry, initfunc)
}
Esempio n. 12
0
File: asm.go Progetto: hurkgu/go
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)
		got := ld.Linklookup(ctxt, ".got", 0)
		rela := ld.Linklookup(ctxt, ".rela.plt", 0)
		if plt.Size == 0 {
			elfsetupplt(ctxt)
		}
		// larl    %r1,_GLOBAL_OFFSET_TABLE_+index

		ld.Adduint8(ctxt, plt, 0xc0)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Addpcrelplus(ctxt, plt, got, got.Size+6) // need variant?

		// add to got: pointer to current pos in plt
		ld.Addaddrplus(ctxt, got, plt, plt.Size+8) // weird but correct
		// lg      %r1,0(%r1)
		ld.Adduint8(ctxt, plt, 0xe3)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x04)
		// br      %r1
		ld.Adduint8(ctxt, plt, 0x07)
		ld.Adduint8(ctxt, plt, 0xf1)
		// basr    %r1,%r0
		ld.Adduint8(ctxt, plt, 0x0d)
		ld.Adduint8(ctxt, plt, 0x10)
		// lgf     %r1,12(%r1)
		ld.Adduint8(ctxt, plt, 0xe3)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x0c)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x14)
		// jg .plt
		ld.Adduint8(ctxt, plt, 0xc0)
		ld.Adduint8(ctxt, plt, 0xf4)

		ld.Adduint32(ctxt, plt, uint32(-((plt.Size - 2) >> 1))) // roll-your-own relocation
		//.plt index
		ld.Adduint32(ctxt, plt, uint32(rela.Size)) // rela size before current entry

		// rela
		ld.Addaddrplus(ctxt, rela, got, got.Size-8)

		ld.Adduint64(ctxt, rela, ld.ELF64_R_INFO(uint32(s.Dynid), ld.R_390_JMP_SLOT))
		ld.Adduint64(ctxt, rela, 0)

		s.Plt = int32(plt.Size - 32)

	} else {
		ctxt.Diag("addpltsym: unsupported binary format")
	}
}
Esempio n. 13
0
File: asm.go Progetto: hurkgu/go
func elfsetupplt(ctxt *ld.Link) {
	plt := ld.Linklookup(ctxt, ".plt", 0)
	got := ld.Linklookup(ctxt, ".got", 0)
	if plt.Size == 0 {
		// stg     %r1,56(%r15)
		ld.Adduint8(ctxt, plt, 0xe3)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0xf0)
		ld.Adduint8(ctxt, plt, 0x38)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x24)
		// larl    %r1,_GLOBAL_OFFSET_TABLE_
		ld.Adduint8(ctxt, plt, 0xc0)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Addpcrelplus(ctxt, plt, got, 6)
		// mvc     48(8,%r15),8(%r1)
		ld.Adduint8(ctxt, plt, 0xd2)
		ld.Adduint8(ctxt, plt, 0x07)
		ld.Adduint8(ctxt, plt, 0xf0)
		ld.Adduint8(ctxt, plt, 0x30)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x08)
		// lg      %r1,16(%r1)
		ld.Adduint8(ctxt, plt, 0xe3)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x10)
		ld.Adduint8(ctxt, plt, 0x00)
		ld.Adduint8(ctxt, plt, 0x04)
		// br      %r1
		ld.Adduint8(ctxt, plt, 0x07)
		ld.Adduint8(ctxt, plt, 0xf1)
		// nopr    %r0
		ld.Adduint8(ctxt, plt, 0x07)
		ld.Adduint8(ctxt, plt, 0x00)
		// nopr    %r0
		ld.Adduint8(ctxt, plt, 0x07)
		ld.Adduint8(ctxt, plt, 0x00)
		// nopr    %r0
		ld.Adduint8(ctxt, plt, 0x07)
		ld.Adduint8(ctxt, plt, 0x00)

		// assume got->size == 0 too
		ld.Addaddrplus(ctxt, got, ld.Linklookup(ctxt, ".dynamic", 0), 0)

		ld.Adduint64(ctxt, got, 0)
		ld.Adduint64(ctxt, got, 0)
	}
}
Esempio n. 14
0
func archinit() {
	// getgoextlinkenabled is based on GO_EXTLINK_ENABLED when
	// Go was built; see ../../make.bash.
	if ld.Linkmode == ld.LinkAuto && obj.Getgoextlinkenabled() == "0" {
		ld.Linkmode = ld.LinkInternal
	}

	switch ld.HEADTYPE {
	default:
		if ld.Linkmode == ld.LinkAuto {
			ld.Linkmode = ld.LinkInternal
		}
		if ld.Linkmode == ld.LinkExternal && obj.Getgoextlinkenabled() != "1" {
			log.Fatalf("cannot use -linkmode=external with -H %s", ld.Headstr(int(ld.HEADTYPE)))
		}

	case obj.Hlinux,
		obj.Hfreebsd,
		obj.Hnacl,
		obj.Hdarwin:
		break
	}

	switch ld.HEADTYPE {
	default:
		ld.Exitf("unknown -H option: %v", ld.HEADTYPE)

	case obj.Hplan9: /* plan 9 */
		ld.HEADR = 32

		if ld.INITTEXT == -1 {
			ld.INITTEXT = 4128
		}
		if ld.INITDAT == -1 {
			ld.INITDAT = 0
		}
		if ld.INITRND == -1 {
			ld.INITRND = 16384
		}

	case obj.Hlinux, /* arm elf */
		obj.Hfreebsd,
		obj.Hnetbsd,
		obj.Hopenbsd:
		ld.Debug['d'] = 0
		// with dynamic linking
		ld.Elfinit()
		ld.HEADR = ld.ELFRESERVE
		if ld.INITTEXT == -1 {
			ld.INITTEXT = 0x10000 + int64(ld.HEADR)
		}
		if ld.INITDAT == -1 {
			ld.INITDAT = 0
		}
		if ld.INITRND == -1 {
			ld.INITRND = 16384
		}

	case obj.Hnacl:
		ld.Elfinit()
		ld.HEADR = 0x10000
		ld.Funcalign = 16
		if ld.INITTEXT == -1 {
			ld.INITTEXT = 0x20000
		}
		if ld.INITDAT == -1 {
			ld.INITDAT = 0
		}
		if ld.INITRND == -1 {
			ld.INITRND = 0x10000
		}

	case obj.Hdarwin: /* apple MACH */
		ld.Debug['w'] = 1 // disable DWARF generataion
		ld.Machoinit()
		ld.HEADR = ld.INITIAL_MACHO_HEADR
		if ld.INITTEXT == -1 {
			ld.INITTEXT = 16384 + int64(ld.HEADR)
		}
		if ld.INITDAT == -1 {
			ld.INITDAT = 0
		}
		if ld.INITRND == -1 {
			ld.INITRND = 16384
		}
	}

	if ld.INITDAT != 0 && ld.INITRND != 0 {
		fmt.Printf("warning: -D0x%x is ignored because of -R0x%x\n", uint64(ld.INITDAT), uint32(ld.INITRND))
	}

	// embed goarm to runtime.goarm
	s := ld.Linklookup(ld.Ctxt, "runtime.goarm", 0)

	s.Type = obj.SRODATA
	ld.Adduint8(ld.Ctxt, s, uint8(ld.Ctxt.Goarm))
}