/
elf.go
2391 lines (2084 loc) · 57.8 KB
/
elf.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ld
import (
"cmd/internal/objabi"
"cmd/internal/sys"
"cmd/link/internal/sym"
"crypto/sha1"
"encoding/binary"
"encoding/hex"
"io"
"path/filepath"
"sort"
"strings"
)
/*
* Derived from:
* $FreeBSD: src/sys/sys/elf32.h,v 1.8.14.1 2005/12/30 22:13:58 marcel Exp $
* $FreeBSD: src/sys/sys/elf64.h,v 1.10.14.1 2005/12/30 22:13:58 marcel Exp $
* $FreeBSD: src/sys/sys/elf_common.h,v 1.15.8.1 2005/12/30 22:13:58 marcel Exp $
* $FreeBSD: src/sys/alpha/include/elf.h,v 1.14 2003/09/25 01:10:22 peter Exp $
* $FreeBSD: src/sys/amd64/include/elf.h,v 1.18 2004/08/03 08:21:48 dfr Exp $
* $FreeBSD: src/sys/arm/include/elf.h,v 1.5.2.1 2006/06/30 21:42:52 cognet Exp $
* $FreeBSD: src/sys/i386/include/elf.h,v 1.16 2004/08/02 19:12:17 dfr Exp $
* $FreeBSD: src/sys/powerpc/include/elf.h,v 1.7 2004/11/02 09:47:01 ssouhlal Exp $
* $FreeBSD: src/sys/sparc64/include/elf.h,v 1.12 2003/09/25 01:10:26 peter Exp $
*
* Copyright (c) 1996-1998 John D. Polstra. All rights reserved.
* Copyright (c) 2001 David E. O'Brien
* Portions Copyright 2009 The Go Authors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/*
* ELF definitions that are independent of architecture or word size.
*/
/*
* Note header. The ".note" section contains an array of notes. Each
* begins with this header, aligned to a word boundary. Immediately
* following the note header is n_namesz bytes of name, padded to the
* next word boundary. Then comes n_descsz bytes of descriptor, again
* padded to a word boundary. The values of n_namesz and n_descsz do
* not include the padding.
*/
type elfNote struct {
nNamesz uint32
nDescsz uint32
nType uint32
}
const (
EI_MAG0 = 0
EI_MAG1 = 1
EI_MAG2 = 2
EI_MAG3 = 3
EI_CLASS = 4
EI_DATA = 5
EI_VERSION = 6
EI_OSABI = 7
EI_ABIVERSION = 8
OLD_EI_BRAND = 8
EI_PAD = 9
EI_NIDENT = 16
ELFMAG0 = 0x7f
ELFMAG1 = 'E'
ELFMAG2 = 'L'
ELFMAG3 = 'F'
SELFMAG = 4
EV_NONE = 0
EV_CURRENT = 1
ELFCLASSNONE = 0
ELFCLASS32 = 1
ELFCLASS64 = 2
ELFDATANONE = 0
ELFDATA2LSB = 1
ELFDATA2MSB = 2
ELFOSABI_NONE = 0
ELFOSABI_HPUX = 1
ELFOSABI_NETBSD = 2
ELFOSABI_LINUX = 3
ELFOSABI_HURD = 4
ELFOSABI_86OPEN = 5
ELFOSABI_SOLARIS = 6
ELFOSABI_AIX = 7
ELFOSABI_IRIX = 8
ELFOSABI_FREEBSD = 9
ELFOSABI_TRU64 = 10
ELFOSABI_MODESTO = 11
ELFOSABI_OPENBSD = 12
ELFOSABI_OPENVMS = 13
ELFOSABI_NSK = 14
ELFOSABI_ARM = 97
ELFOSABI_STANDALONE = 255
ELFOSABI_SYSV = ELFOSABI_NONE
ELFOSABI_MONTEREY = ELFOSABI_AIX
ET_NONE = 0
ET_REL = 1
ET_EXEC = 2
ET_DYN = 3
ET_CORE = 4
ET_LOOS = 0xfe00
ET_HIOS = 0xfeff
ET_LOPROC = 0xff00
ET_HIPROC = 0xffff
EM_NONE = 0
EM_M32 = 1
EM_SPARC = 2
EM_386 = 3
EM_68K = 4
EM_88K = 5
EM_860 = 7
EM_MIPS = 8
EM_S370 = 9
EM_MIPS_RS3_LE = 10
EM_PARISC = 15
EM_VPP500 = 17
EM_SPARC32PLUS = 18
EM_960 = 19
EM_PPC = 20
EM_PPC64 = 21
EM_S390 = 22
EM_V800 = 36
EM_FR20 = 37
EM_RH32 = 38
EM_RCE = 39
EM_ARM = 40
EM_SH = 42
EM_SPARCV9 = 43
EM_TRICORE = 44
EM_ARC = 45
EM_H8_300 = 46
EM_H8_300H = 47
EM_H8S = 48
EM_H8_500 = 49
EM_IA_64 = 50
EM_MIPS_X = 51
EM_COLDFIRE = 52
EM_68HC12 = 53
EM_MMA = 54
EM_PCP = 55
EM_NCPU = 56
EM_NDR1 = 57
EM_STARCORE = 58
EM_ME16 = 59
EM_ST100 = 60
EM_TINYJ = 61
EM_X86_64 = 62
EM_AARCH64 = 183
EM_486 = 6
EM_MIPS_RS4_BE = 10
EM_ALPHA_STD = 41
EM_ALPHA = 0x9026
SHN_UNDEF = 0
SHN_LORESERVE = 0xff00
SHN_LOPROC = 0xff00
SHN_HIPROC = 0xff1f
SHN_LOOS = 0xff20
SHN_HIOS = 0xff3f
SHN_ABS = 0xfff1
SHN_COMMON = 0xfff2
SHN_XINDEX = 0xffff
SHN_HIRESERVE = 0xffff
SHT_NULL = 0
SHT_PROGBITS = 1
SHT_SYMTAB = 2
SHT_STRTAB = 3
SHT_RELA = 4
SHT_HASH = 5
SHT_DYNAMIC = 6
SHT_NOTE = 7
SHT_NOBITS = 8
SHT_REL = 9
SHT_SHLIB = 10
SHT_DYNSYM = 11
SHT_INIT_ARRAY = 14
SHT_FINI_ARRAY = 15
SHT_PREINIT_ARRAY = 16
SHT_GROUP = 17
SHT_SYMTAB_SHNDX = 18
SHT_LOOS = 0x60000000
SHT_HIOS = 0x6fffffff
SHT_GNU_VERDEF = 0x6ffffffd
SHT_GNU_VERNEED = 0x6ffffffe
SHT_GNU_VERSYM = 0x6fffffff
SHT_LOPROC = 0x70000000
SHT_ARM_ATTRIBUTES = 0x70000003
SHT_HIPROC = 0x7fffffff
SHT_LOUSER = 0x80000000
SHT_HIUSER = 0xffffffff
SHF_WRITE = 0x1
SHF_ALLOC = 0x2
SHF_EXECINSTR = 0x4
SHF_MERGE = 0x10
SHF_STRINGS = 0x20
SHF_INFO_LINK = 0x40
SHF_LINK_ORDER = 0x80
SHF_OS_NONCONFORMING = 0x100
SHF_GROUP = 0x200
SHF_TLS = 0x400
SHF_MASKOS = 0x0ff00000
SHF_MASKPROC = 0xf0000000
PT_NULL = 0
PT_LOAD = 1
PT_DYNAMIC = 2
PT_INTERP = 3
PT_NOTE = 4
PT_SHLIB = 5
PT_PHDR = 6
PT_TLS = 7
PT_LOOS = 0x60000000
PT_HIOS = 0x6fffffff
PT_LOPROC = 0x70000000
PT_HIPROC = 0x7fffffff
PT_GNU_STACK = 0x6474e551
PT_GNU_RELRO = 0x6474e552
PT_PAX_FLAGS = 0x65041580
PT_SUNWSTACK = 0x6ffffffb
PF_X = 0x1
PF_W = 0x2
PF_R = 0x4
PF_MASKOS = 0x0ff00000
PF_MASKPROC = 0xf0000000
DT_NULL = 0
DT_NEEDED = 1
DT_PLTRELSZ = 2
DT_PLTGOT = 3
DT_HASH = 4
DT_STRTAB = 5
DT_SYMTAB = 6
DT_RELA = 7
DT_RELASZ = 8
DT_RELAENT = 9
DT_STRSZ = 10
DT_SYMENT = 11
DT_INIT = 12
DT_FINI = 13
DT_SONAME = 14
DT_RPATH = 15
DT_SYMBOLIC = 16
DT_REL = 17
DT_RELSZ = 18
DT_RELENT = 19
DT_PLTREL = 20
DT_DEBUG = 21
DT_TEXTREL = 22
DT_JMPREL = 23
DT_BIND_NOW = 24
DT_INIT_ARRAY = 25
DT_FINI_ARRAY = 26
DT_INIT_ARRAYSZ = 27
DT_FINI_ARRAYSZ = 28
DT_RUNPATH = 29
DT_FLAGS = 30
DT_ENCODING = 32
DT_PREINIT_ARRAY = 32
DT_PREINIT_ARRAYSZ = 33
DT_LOOS = 0x6000000d
DT_HIOS = 0x6ffff000
DT_LOPROC = 0x70000000
DT_HIPROC = 0x7fffffff
DT_VERNEED = 0x6ffffffe
DT_VERNEEDNUM = 0x6fffffff
DT_VERSYM = 0x6ffffff0
DT_PPC64_GLINK = DT_LOPROC + 0
DT_PPC64_OPT = DT_LOPROC + 3
DF_ORIGIN = 0x0001
DF_SYMBOLIC = 0x0002
DF_TEXTREL = 0x0004
DF_BIND_NOW = 0x0008
DF_STATIC_TLS = 0x0010
NT_PRSTATUS = 1
NT_FPREGSET = 2
NT_PRPSINFO = 3
STB_LOCAL = 0
STB_GLOBAL = 1
STB_WEAK = 2
STB_LOOS = 10
STB_HIOS = 12
STB_LOPROC = 13
STB_HIPROC = 15
STT_NOTYPE = 0
STT_OBJECT = 1
STT_FUNC = 2
STT_SECTION = 3
STT_FILE = 4
STT_COMMON = 5
STT_TLS = 6
STT_LOOS = 10
STT_HIOS = 12
STT_LOPROC = 13
STT_HIPROC = 15
STV_DEFAULT = 0x0
STV_INTERNAL = 0x1
STV_HIDDEN = 0x2
STV_PROTECTED = 0x3
STN_UNDEF = 0
)
/* For accessing the fields of r_info. */
/* For constructing r_info from field values. */
/*
* Relocation types.
*/
const (
ARM_MAGIC_TRAMP_NUMBER = 0x5c000003
)
/*
* Symbol table entries.
*/
/* For accessing the fields of st_info. */
/* For constructing st_info from field values. */
/* For accessing the fields of st_other. */
/*
* ELF header.
*/
type ElfEhdr struct {
ident [EI_NIDENT]uint8
type_ uint16
machine uint16
version uint32
entry uint64
phoff uint64
shoff uint64
flags uint32
ehsize uint16
phentsize uint16
phnum uint16
shentsize uint16
shnum uint16
shstrndx uint16
}
/*
* Section header.
*/
type ElfShdr struct {
name uint32
type_ uint32
flags uint64
addr uint64
off uint64
size uint64
link uint32
info uint32
addralign uint64
entsize uint64
shnum int
}
/*
* Program header.
*/
type ElfPhdr struct {
type_ uint32
flags uint32
off uint64
vaddr uint64
paddr uint64
filesz uint64
memsz uint64
align uint64
}
/* For accessing the fields of r_info. */
/* For constructing r_info from field values. */
/*
* Symbol table entries.
*/
/* For accessing the fields of st_info. */
/* For constructing st_info from field values. */
/* For accessing the fields of st_other. */
/*
* Go linker interface
*/
const (
ELF64HDRSIZE = 64
ELF64PHDRSIZE = 56
ELF64SHDRSIZE = 64
ELF64RELSIZE = 16
ELF64RELASIZE = 24
ELF64SYMSIZE = 24
ELF32HDRSIZE = 52
ELF32PHDRSIZE = 32
ELF32SHDRSIZE = 40
ELF32SYMSIZE = 16
ELF32RELSIZE = 8
)
/*
* The interface uses the 64-bit structures always,
* to avoid code duplication. The writers know how to
* marshal a 32-bit representation from the 64-bit structure.
*/
var Elfstrdat []byte
/*
* Total amount of space to reserve at the start of the file
* for Header, PHeaders, SHeaders, and interp.
* May waste some.
* On FreeBSD, cannot be larger than a page.
*/
const (
ELFRESERVE = 4096
)
/*
* We use the 64-bit data structures on both 32- and 64-bit machines
* in order to write the code just once. The 64-bit data structure is
* written in the 32-bit format on the 32-bit machines.
*/
const (
NSECT = 400
)
var (
Nelfsym = 1
elf64 bool
// Either ".rel" or ".rela" depending on which type of relocation the
// target platform uses.
elfRelType string
ehdr ElfEhdr
phdr [NSECT]*ElfPhdr
shdr [NSECT]*ElfShdr
interp string
)
type Elfstring struct {
s string
off int
}
var elfstr [100]Elfstring
var nelfstr int
var buildinfo []byte
/*
Initialize the global variable that describes the ELF header. It will be updated as
we write section and prog headers.
*/
func Elfinit(ctxt *Link) {
ctxt.IsELF = true
if ctxt.Arch.InFamily(sys.AMD64, sys.ARM64, sys.MIPS64, sys.PPC64, sys.S390X) {
elfRelType = ".rela"
} else {
elfRelType = ".rel"
}
switch ctxt.Arch.Family {
// 64-bit architectures
case sys.PPC64, sys.S390X:
if ctxt.Arch.ByteOrder == binary.BigEndian {
ehdr.flags = 1 /* Version 1 ABI */
} else {
ehdr.flags = 2 /* Version 2 ABI */
}
fallthrough
case sys.AMD64, sys.ARM64, sys.MIPS64:
if ctxt.Arch.Family == sys.MIPS64 {
ehdr.flags = 0x20000004 /* MIPS 3 CPIC */
}
elf64 = true
ehdr.phoff = ELF64HDRSIZE /* Must be ELF64HDRSIZE: first PHdr must follow ELF header */
ehdr.shoff = ELF64HDRSIZE /* Will move as we add PHeaders */
ehdr.ehsize = ELF64HDRSIZE /* Must be ELF64HDRSIZE */
ehdr.phentsize = ELF64PHDRSIZE /* Must be ELF64PHDRSIZE */
ehdr.shentsize = ELF64SHDRSIZE /* Must be ELF64SHDRSIZE */
// 32-bit architectures
case sys.ARM, sys.MIPS:
if ctxt.Arch.Family == sys.ARM {
// we use EABI on linux/arm, freebsd/arm, netbsd/arm.
if ctxt.HeadType == objabi.Hlinux || ctxt.HeadType == objabi.Hfreebsd || ctxt.HeadType == objabi.Hnetbsd {
// We set a value here that makes no indication of which
// float ABI the object uses, because this is information
// used by the dynamic linker to compare executables and
// shared libraries -- so it only matters for cgo calls, and
// the information properly comes from the object files
// produced by the host C compiler. parseArmAttributes in
// ldelf.go reads that information and updates this field as
// appropriate.
ehdr.flags = 0x5000002 // has entry point, Version5 EABI
}
} else if ctxt.Arch.Family == sys.MIPS {
ehdr.flags = 0x50001004 /* MIPS 32 CPIC O32*/
}
fallthrough
default:
ehdr.phoff = ELF32HDRSIZE
/* Must be ELF32HDRSIZE: first PHdr must follow ELF header */
ehdr.shoff = ELF32HDRSIZE /* Will move as we add PHeaders */
ehdr.ehsize = ELF32HDRSIZE /* Must be ELF32HDRSIZE */
ehdr.phentsize = ELF32PHDRSIZE /* Must be ELF32PHDRSIZE */
ehdr.shentsize = ELF32SHDRSIZE /* Must be ELF32SHDRSIZE */
}
}
// Make sure PT_LOAD is aligned properly and
// that there is no gap,
// correct ELF loaders will do this implicitly,
// but buggy ELF loaders like the one in some
// versions of QEMU and UPX won't.
func fixElfPhdr(e *ElfPhdr) {
frag := int(e.vaddr & (e.align - 1))
e.off -= uint64(frag)
e.vaddr -= uint64(frag)
e.paddr -= uint64(frag)
e.filesz += uint64(frag)
e.memsz += uint64(frag)
}
func elf64phdr(out *OutBuf, e *ElfPhdr) {
if e.type_ == PT_LOAD {
fixElfPhdr(e)
}
out.Write32(e.type_)
out.Write32(e.flags)
out.Write64(e.off)
out.Write64(e.vaddr)
out.Write64(e.paddr)
out.Write64(e.filesz)
out.Write64(e.memsz)
out.Write64(e.align)
}
func elf32phdr(out *OutBuf, e *ElfPhdr) {
if e.type_ == PT_LOAD {
fixElfPhdr(e)
}
out.Write32(e.type_)
out.Write32(uint32(e.off))
out.Write32(uint32(e.vaddr))
out.Write32(uint32(e.paddr))
out.Write32(uint32(e.filesz))
out.Write32(uint32(e.memsz))
out.Write32(e.flags)
out.Write32(uint32(e.align))
}
func elf64shdr(out *OutBuf, e *ElfShdr) {
out.Write32(e.name)
out.Write32(e.type_)
out.Write64(e.flags)
out.Write64(e.addr)
out.Write64(e.off)
out.Write64(e.size)
out.Write32(e.link)
out.Write32(e.info)
out.Write64(e.addralign)
out.Write64(e.entsize)
}
func elf32shdr(out *OutBuf, e *ElfShdr) {
out.Write32(e.name)
out.Write32(e.type_)
out.Write32(uint32(e.flags))
out.Write32(uint32(e.addr))
out.Write32(uint32(e.off))
out.Write32(uint32(e.size))
out.Write32(e.link)
out.Write32(e.info)
out.Write32(uint32(e.addralign))
out.Write32(uint32(e.entsize))
}
func elfwriteshdrs(out *OutBuf) uint32 {
if elf64 {
for i := 0; i < int(ehdr.shnum); i++ {
elf64shdr(out, shdr[i])
}
return uint32(ehdr.shnum) * ELF64SHDRSIZE
}
for i := 0; i < int(ehdr.shnum); i++ {
elf32shdr(out, shdr[i])
}
return uint32(ehdr.shnum) * ELF32SHDRSIZE
}
func elfsetstring(s *sym.Symbol, str string, off int) {
if nelfstr >= len(elfstr) {
Errorf(s, "too many elf strings")
errorexit()
}
elfstr[nelfstr].s = str
elfstr[nelfstr].off = off
nelfstr++
}
func elfwritephdrs(out *OutBuf) uint32 {
if elf64 {
for i := 0; i < int(ehdr.phnum); i++ {
elf64phdr(out, phdr[i])
}
return uint32(ehdr.phnum) * ELF64PHDRSIZE
}
for i := 0; i < int(ehdr.phnum); i++ {
elf32phdr(out, phdr[i])
}
return uint32(ehdr.phnum) * ELF32PHDRSIZE
}
func newElfPhdr() *ElfPhdr {
e := new(ElfPhdr)
if ehdr.phnum >= NSECT {
Errorf(nil, "too many phdrs")
} else {
phdr[ehdr.phnum] = e
ehdr.phnum++
}
if elf64 {
ehdr.shoff += ELF64PHDRSIZE
} else {
ehdr.shoff += ELF32PHDRSIZE
}
return e
}
func newElfShdr(name int64) *ElfShdr {
e := new(ElfShdr)
e.name = uint32(name)
e.shnum = int(ehdr.shnum)
if ehdr.shnum >= NSECT {
Errorf(nil, "too many shdrs")
} else {
shdr[ehdr.shnum] = e
ehdr.shnum++
}
return e
}
func getElfEhdr() *ElfEhdr {
return &ehdr
}
func elf64writehdr(out *OutBuf) uint32 {
out.Write(ehdr.ident[:])
out.Write16(ehdr.type_)
out.Write16(ehdr.machine)
out.Write32(ehdr.version)
out.Write64(ehdr.entry)
out.Write64(ehdr.phoff)
out.Write64(ehdr.shoff)
out.Write32(ehdr.flags)
out.Write16(ehdr.ehsize)
out.Write16(ehdr.phentsize)
out.Write16(ehdr.phnum)
out.Write16(ehdr.shentsize)
out.Write16(ehdr.shnum)
out.Write16(ehdr.shstrndx)
return ELF64HDRSIZE
}
func elf32writehdr(out *OutBuf) uint32 {
out.Write(ehdr.ident[:])
out.Write16(ehdr.type_)
out.Write16(ehdr.machine)
out.Write32(ehdr.version)
out.Write32(uint32(ehdr.entry))
out.Write32(uint32(ehdr.phoff))
out.Write32(uint32(ehdr.shoff))
out.Write32(ehdr.flags)
out.Write16(ehdr.ehsize)
out.Write16(ehdr.phentsize)
out.Write16(ehdr.phnum)
out.Write16(ehdr.shentsize)
out.Write16(ehdr.shnum)
out.Write16(ehdr.shstrndx)
return ELF32HDRSIZE
}
func elfwritehdr(out *OutBuf) uint32 {
if elf64 {
return elf64writehdr(out)
}
return elf32writehdr(out)
}
/* Taken directly from the definition document for ELF64 */
func elfhash(name string) uint32 {
var h uint32
for i := 0; i < len(name); i++ {
h = (h << 4) + uint32(name[i])
if g := h & 0xf0000000; g != 0 {
h ^= g >> 24
}
h &= 0x0fffffff
}
return h
}
func Elfwritedynent(ctxt *Link, s *sym.Symbol, tag int, val uint64) {
if elf64 {
s.AddUint64(ctxt.Arch, uint64(tag))
s.AddUint64(ctxt.Arch, val)
} else {
s.AddUint32(ctxt.Arch, uint32(tag))
s.AddUint32(ctxt.Arch, uint32(val))
}
}
func elfwritedynentsym(ctxt *Link, s *sym.Symbol, tag int, t *sym.Symbol) {
Elfwritedynentsymplus(ctxt, s, tag, t, 0)
}
func Elfwritedynentsymplus(ctxt *Link, s *sym.Symbol, tag int, t *sym.Symbol, add int64) {
if elf64 {
s.AddUint64(ctxt.Arch, uint64(tag))
} else {
s.AddUint32(ctxt.Arch, uint32(tag))
}
s.AddAddrPlus(ctxt.Arch, t, add)
}
func elfwritedynentsymsize(ctxt *Link, s *sym.Symbol, tag int, t *sym.Symbol) {
if elf64 {
s.AddUint64(ctxt.Arch, uint64(tag))
} else {
s.AddUint32(ctxt.Arch, uint32(tag))
}
s.AddSize(ctxt.Arch, t)
}
func elfinterp(sh *ElfShdr, startva uint64, resoff uint64, p string) int {
interp = p
n := len(interp) + 1
sh.addr = startva + resoff - uint64(n)
sh.off = resoff - uint64(n)
sh.size = uint64(n)
return n
}
func elfwriteinterp(out *OutBuf) int {
sh := elfshname(".interp")
out.SeekSet(int64(sh.off))
out.WriteString(interp)
out.Write8(0)
return int(sh.size)
}
func elfnote(sh *ElfShdr, startva uint64, resoff uint64, sz int) int {
n := 3*4 + uint64(sz) + resoff%4
sh.type_ = SHT_NOTE
sh.flags = SHF_ALLOC
sh.addralign = 4
sh.addr = startva + resoff - n
sh.off = resoff - n
sh.size = n - resoff%4
return int(n)
}
func elfwritenotehdr(out *OutBuf, str string, namesz uint32, descsz uint32, tag uint32) *ElfShdr {
sh := elfshname(str)
// Write Elf_Note header.
out.SeekSet(int64(sh.off))
out.Write32(namesz)
out.Write32(descsz)
out.Write32(tag)
return sh
}
// NetBSD Signature (as per sys/exec_elf.h)
const (
ELF_NOTE_NETBSD_NAMESZ = 7
ELF_NOTE_NETBSD_DESCSZ = 4
ELF_NOTE_NETBSD_TAG = 1
ELF_NOTE_NETBSD_VERSION = 599000000 /* NetBSD 5.99 */
)
var ELF_NOTE_NETBSD_NAME = []byte("NetBSD\x00")
func elfnetbsdsig(sh *ElfShdr, startva uint64, resoff uint64) int {
n := int(Rnd(ELF_NOTE_NETBSD_NAMESZ, 4) + Rnd(ELF_NOTE_NETBSD_DESCSZ, 4))
return elfnote(sh, startva, resoff, n)
}
func elfwritenetbsdsig(out *OutBuf) int {
// Write Elf_Note header.
sh := elfwritenotehdr(out, ".note.netbsd.ident", ELF_NOTE_NETBSD_NAMESZ, ELF_NOTE_NETBSD_DESCSZ, ELF_NOTE_NETBSD_TAG)
if sh == nil {
return 0
}
// Followed by NetBSD string and version.
out.Write(ELF_NOTE_NETBSD_NAME)
out.Write8(0)
out.Write32(ELF_NOTE_NETBSD_VERSION)
return int(sh.size)
}
// OpenBSD Signature
const (
ELF_NOTE_OPENBSD_NAMESZ = 8
ELF_NOTE_OPENBSD_DESCSZ = 4
ELF_NOTE_OPENBSD_TAG = 1
ELF_NOTE_OPENBSD_VERSION = 0
)
var ELF_NOTE_OPENBSD_NAME = []byte("OpenBSD\x00")
func elfopenbsdsig(sh *ElfShdr, startva uint64, resoff uint64) int {
n := ELF_NOTE_OPENBSD_NAMESZ + ELF_NOTE_OPENBSD_DESCSZ
return elfnote(sh, startva, resoff, n)
}
func elfwriteopenbsdsig(out *OutBuf) int {
// Write Elf_Note header.
sh := elfwritenotehdr(out, ".note.openbsd.ident", ELF_NOTE_OPENBSD_NAMESZ, ELF_NOTE_OPENBSD_DESCSZ, ELF_NOTE_OPENBSD_TAG)
if sh == nil {
return 0
}
// Followed by OpenBSD string and version.
out.Write(ELF_NOTE_OPENBSD_NAME)
out.Write32(ELF_NOTE_OPENBSD_VERSION)
return int(sh.size)
}
func addbuildinfo(val string) {
if !strings.HasPrefix(val, "0x") {
Exitf("-B argument must start with 0x: %s", val)
}
ov := val
val = val[2:]
const maxLen = 32
if hex.DecodedLen(len(val)) > maxLen {
Exitf("-B option too long (max %d digits): %s", maxLen, ov)
}
b, err := hex.DecodeString(val)
if err != nil {
if err == hex.ErrLength {
Exitf("-B argument must have even number of digits: %s", ov)
}
if inv, ok := err.(hex.InvalidByteError); ok {
Exitf("-B argument contains invalid hex digit %c: %s", byte(inv), ov)
}
Exitf("-B argument contains invalid hex: %s", ov)
}
buildinfo = b
}
// Build info note
const (
ELF_NOTE_BUILDINFO_NAMESZ = 4
ELF_NOTE_BUILDINFO_TAG = 3
)
var ELF_NOTE_BUILDINFO_NAME = []byte("GNU\x00")
func elfbuildinfo(sh *ElfShdr, startva uint64, resoff uint64) int {
n := int(ELF_NOTE_BUILDINFO_NAMESZ + Rnd(int64(len(buildinfo)), 4))
return elfnote(sh, startva, resoff, n)
}
func elfgobuildid(sh *ElfShdr, startva uint64, resoff uint64) int {
n := len(ELF_NOTE_GO_NAME) + int(Rnd(int64(len(*flagBuildid)), 4))
return elfnote(sh, startva, resoff, n)
}
func elfwritebuildinfo(out *OutBuf) int {
sh := elfwritenotehdr(out, ".note.gnu.build-id", ELF_NOTE_BUILDINFO_NAMESZ, uint32(len(buildinfo)), ELF_NOTE_BUILDINFO_TAG)
if sh == nil {
return 0
}
out.Write(ELF_NOTE_BUILDINFO_NAME)
out.Write(buildinfo)
var zero = make([]byte, 4)
out.Write(zero[:int(Rnd(int64(len(buildinfo)), 4)-int64(len(buildinfo)))])
return int(sh.size)
}
func elfwritegobuildid(out *OutBuf) int {
sh := elfwritenotehdr(out, ".note.go.buildid", uint32(len(ELF_NOTE_GO_NAME)), uint32(len(*flagBuildid)), ELF_NOTE_GOBUILDID_TAG)
if sh == nil {
return 0
}
out.Write(ELF_NOTE_GO_NAME)
out.Write([]byte(*flagBuildid))
var zero = make([]byte, 4)
out.Write(zero[:int(Rnd(int64(len(*flagBuildid)), 4)-int64(len(*flagBuildid)))])
return int(sh.size)
}
// Go specific notes
const (
ELF_NOTE_GOPKGLIST_TAG = 1
ELF_NOTE_GOABIHASH_TAG = 2
ELF_NOTE_GODEPS_TAG = 3
ELF_NOTE_GOBUILDID_TAG = 4
)
var ELF_NOTE_GO_NAME = []byte("Go\x00\x00")
var elfverneed int
type Elfaux struct {
next *Elfaux
num int
vers string
}
type Elflib struct {
next *Elflib
aux *Elfaux
file string
}
func addelflib(list **Elflib, file string, vers string) *Elfaux {
var lib *Elflib
for lib = *list; lib != nil; lib = lib.next {
if lib.file == file {
goto havelib
}
}
lib = new(Elflib)
lib.next = *list
lib.file = file
*list = lib
havelib:
for aux := lib.aux; aux != nil; aux = aux.next {
if aux.vers == vers {
return aux
}
}
aux := new(Elfaux)
aux.next = lib.aux
aux.vers = vers