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go/src/cmd/link/internal/ld/elf.go
Michael Hudson-Doyle be2ee2a4b4 cmd/internal/objabi, cmd/link: move linker-only symkind values into linker 
Many (most!) of the values of objapi.SymKind are used only in the linker, so
this creates a separate cmd/link/internal/ld.SymKind type, removes most values
from SymKind and maps one to the other when reading object files in the linker.

Two of the remaining objapi.SymKind values are only checked for, never set and
so will never be actually found but I wanted to keep this to the most
mechanical change possible.

Change-Id: I4bbc5aed6713cab3e8de732e6e288eb77be0474c
Reviewed-on: https://go-review.googlesource.com/40985
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-04-27 21:56:12 +00:00

2846 lines
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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"
"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 (
R_X86_64_NONE = 0
R_X86_64_64 = 1
R_X86_64_PC32 = 2
R_X86_64_GOT32 = 3
R_X86_64_PLT32 = 4
R_X86_64_COPY = 5
R_X86_64_GLOB_DAT = 6
R_X86_64_JMP_SLOT = 7
R_X86_64_RELATIVE = 8
R_X86_64_GOTPCREL = 9
R_X86_64_32 = 10
R_X86_64_32S = 11
R_X86_64_16 = 12
R_X86_64_PC16 = 13
R_X86_64_8 = 14
R_X86_64_PC8 = 15
R_X86_64_DTPMOD64 = 16
R_X86_64_DTPOFF64 = 17
R_X86_64_TPOFF64 = 18
R_X86_64_TLSGD = 19
R_X86_64_TLSLD = 20
R_X86_64_DTPOFF32 = 21
R_X86_64_GOTTPOFF = 22
R_X86_64_TPOFF32 = 23
R_X86_64_PC64 = 24
R_X86_64_GOTOFF64 = 25
R_X86_64_GOTPC32 = 26
R_X86_64_GOT64 = 27
R_X86_64_GOTPCREL64 = 28
R_X86_64_GOTPC64 = 29
R_X86_64_GOTPLT64 = 30
R_X86_64_PLTOFF64 = 31
R_X86_64_SIZE32 = 32
R_X86_64_SIZE64 = 33
R_X86_64_GOTPC32_TLSDEC = 34
R_X86_64_TLSDESC_CALL = 35
R_X86_64_TLSDESC = 36
R_X86_64_IRELATIVE = 37
R_X86_64_PC32_BND = 40
R_X86_64_GOTPCRELX = 41
R_X86_64_REX_GOTPCRELX = 42
R_AARCH64_ABS64 = 257
R_AARCH64_ABS32 = 258
R_AARCH64_CALL26 = 283
R_AARCH64_ADR_PREL_PG_HI21 = 275
R_AARCH64_ADD_ABS_LO12_NC = 277
R_AARCH64_LDST8_ABS_LO12_NC = 278
R_AARCH64_LDST16_ABS_LO12_NC = 284
R_AARCH64_LDST32_ABS_LO12_NC = 285
R_AARCH64_LDST64_ABS_LO12_NC = 286
R_AARCH64_ADR_GOT_PAGE = 311
R_AARCH64_LD64_GOT_LO12_NC = 312
R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 = 541
R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC = 542
R_AARCH64_TLSLE_MOVW_TPREL_G0 = 547
R_ALPHA_NONE = 0
R_ALPHA_REFLONG = 1
R_ALPHA_REFQUAD = 2
R_ALPHA_GPREL32 = 3
R_ALPHA_LITERAL = 4
R_ALPHA_LITUSE = 5
R_ALPHA_GPDISP = 6
R_ALPHA_BRADDR = 7
R_ALPHA_HINT = 8
R_ALPHA_SREL16 = 9
R_ALPHA_SREL32 = 10
R_ALPHA_SREL64 = 11
R_ALPHA_OP_PUSH = 12
R_ALPHA_OP_STORE = 13
R_ALPHA_OP_PSUB = 14
R_ALPHA_OP_PRSHIFT = 15
R_ALPHA_GPVALUE = 16
R_ALPHA_GPRELHIGH = 17
R_ALPHA_GPRELLOW = 18
R_ALPHA_IMMED_GP_16 = 19
R_ALPHA_IMMED_GP_HI32 = 20
R_ALPHA_IMMED_SCN_HI32 = 21
R_ALPHA_IMMED_BR_HI32 = 22
R_ALPHA_IMMED_LO32 = 23
R_ALPHA_COPY = 24
R_ALPHA_GLOB_DAT = 25
R_ALPHA_JMP_SLOT = 26
R_ALPHA_RELATIVE = 27
R_ARM_NONE = 0
R_ARM_PC24 = 1
R_ARM_ABS32 = 2
R_ARM_REL32 = 3
R_ARM_PC13 = 4
R_ARM_ABS16 = 5
R_ARM_ABS12 = 6
R_ARM_THM_ABS5 = 7
R_ARM_ABS8 = 8
R_ARM_SBREL32 = 9
R_ARM_THM_PC22 = 10
R_ARM_THM_PC8 = 11
R_ARM_AMP_VCALL9 = 12
R_ARM_SWI24 = 13
R_ARM_THM_SWI8 = 14
R_ARM_XPC25 = 15
R_ARM_THM_XPC22 = 16
R_ARM_COPY = 20
R_ARM_GLOB_DAT = 21
R_ARM_JUMP_SLOT = 22
R_ARM_RELATIVE = 23
R_ARM_GOTOFF = 24
R_ARM_GOTPC = 25
R_ARM_GOT32 = 26
R_ARM_PLT32 = 27
R_ARM_CALL = 28
R_ARM_JUMP24 = 29
R_ARM_V4BX = 40
R_ARM_GOT_PREL = 96
R_ARM_GNU_VTENTRY = 100
R_ARM_GNU_VTINHERIT = 101
R_ARM_TLS_IE32 = 107
R_ARM_TLS_LE32 = 108
R_ARM_RSBREL32 = 250
R_ARM_THM_RPC22 = 251
R_ARM_RREL32 = 252
R_ARM_RABS32 = 253
R_ARM_RPC24 = 254
R_ARM_RBASE = 255
R_386_NONE = 0
R_386_32 = 1
R_386_PC32 = 2
R_386_GOT32 = 3
R_386_PLT32 = 4
R_386_COPY = 5
R_386_GLOB_DAT = 6
R_386_JMP_SLOT = 7
R_386_RELATIVE = 8
R_386_GOTOFF = 9
R_386_GOTPC = 10
R_386_TLS_TPOFF = 14
R_386_TLS_IE = 15
R_386_TLS_GOTIE = 16
R_386_TLS_LE = 17
R_386_TLS_GD = 18
R_386_TLS_LDM = 19
R_386_TLS_GD_32 = 24
R_386_TLS_GD_PUSH = 25
R_386_TLS_GD_CALL = 26
R_386_TLS_GD_POP = 27
R_386_TLS_LDM_32 = 28
R_386_TLS_LDM_PUSH = 29
R_386_TLS_LDM_CALL = 30
R_386_TLS_LDM_POP = 31
R_386_TLS_LDO_32 = 32
R_386_TLS_IE_32 = 33
R_386_TLS_LE_32 = 34
R_386_TLS_DTPMOD32 = 35
R_386_TLS_DTPOFF32 = 36
R_386_TLS_TPOFF32 = 37
R_386_TLS_GOTDESC = 39
R_386_TLS_DESC_CALL = 40
R_386_TLS_DESC = 41
R_386_IRELATIVE = 42
R_386_GOT32X = 43
R_MIPS_NONE = 0
R_MIPS_16 = 1
R_MIPS_32 = 2
R_MIPS_REL32 = 3
R_MIPS_26 = 4
R_MIPS_HI16 = 5
R_MIPS_LO16 = 6
R_MIPS_GPREL16 = 7
R_MIPS_LITERAL = 8
R_MIPS_GOT16 = 9
R_MIPS_PC16 = 10
R_MIPS_CALL16 = 11
R_MIPS_GPREL32 = 12
R_MIPS_SHIFT5 = 16
R_MIPS_SHIFT6 = 17
R_MIPS_64 = 18
R_MIPS_GOT_DISP = 19
R_MIPS_GOT_PAGE = 20
R_MIPS_GOT_OFST = 21
R_MIPS_GOT_HI16 = 22
R_MIPS_GOT_LO16 = 23
R_MIPS_SUB = 24
R_MIPS_INSERT_A = 25
R_MIPS_INSERT_B = 26
R_MIPS_DELETE = 27
R_MIPS_HIGHER = 28
R_MIPS_HIGHEST = 29
R_MIPS_CALL_HI16 = 30
R_MIPS_CALL_LO16 = 31
R_MIPS_SCN_DISP = 32
R_MIPS_REL16 = 33
R_MIPS_ADD_IMMEDIATE = 34
R_MIPS_PJUMP = 35
R_MIPS_RELGOT = 36
R_MIPS_JALR = 37
R_MIPS_TLS_DTPMOD32 = 38
R_MIPS_TLS_DTPREL32 = 39
R_MIPS_TLS_DTPMOD64 = 40
R_MIPS_TLS_DTPREL64 = 41
R_MIPS_TLS_GD = 42
R_MIPS_TLS_LDM = 43
R_MIPS_TLS_DTPREL_HI16 = 44
R_MIPS_TLS_DTPREL_LO16 = 45
R_MIPS_TLS_GOTTPREL = 46
R_MIPS_TLS_TPREL32 = 47
R_MIPS_TLS_TPREL64 = 48
R_MIPS_TLS_TPREL_HI16 = 49
R_MIPS_TLS_TPREL_LO16 = 50
R_PPC_NONE = 0
R_PPC_ADDR32 = 1
R_PPC_ADDR24 = 2
R_PPC_ADDR16 = 3
R_PPC_ADDR16_LO = 4
R_PPC_ADDR16_HI = 5
R_PPC_ADDR16_HA = 6
R_PPC_ADDR14 = 7
R_PPC_ADDR14_BRTAKEN = 8
R_PPC_ADDR14_BRNTAKEN = 9
R_PPC_REL24 = 10
R_PPC_REL14 = 11
R_PPC_REL14_BRTAKEN = 12
R_PPC_REL14_BRNTAKEN = 13
R_PPC_GOT16 = 14
R_PPC_GOT16_LO = 15
R_PPC_GOT16_HI = 16
R_PPC_GOT16_HA = 17
R_PPC_PLTREL24 = 18
R_PPC_COPY = 19
R_PPC_GLOB_DAT = 20
R_PPC_JMP_SLOT = 21
R_PPC_RELATIVE = 22
R_PPC_LOCAL24PC = 23
R_PPC_UADDR32 = 24
R_PPC_UADDR16 = 25
R_PPC_REL32 = 26
R_PPC_PLT32 = 27
R_PPC_PLTREL32 = 28
R_PPC_PLT16_LO = 29
R_PPC_PLT16_HI = 30
R_PPC_PLT16_HA = 31
R_PPC_SDAREL16 = 32
R_PPC_SECTOFF = 33
R_PPC_SECTOFF_LO = 34
R_PPC_SECTOFF_HI = 35
R_PPC_SECTOFF_HA = 36
R_PPC_TLS = 67
R_PPC_DTPMOD32 = 68
R_PPC_TPREL16 = 69
R_PPC_TPREL16_LO = 70
R_PPC_TPREL16_HI = 71
R_PPC_TPREL16_HA = 72
R_PPC_TPREL32 = 73
R_PPC_DTPREL16 = 74
R_PPC_DTPREL16_LO = 75
R_PPC_DTPREL16_HI = 76
R_PPC_DTPREL16_HA = 77
R_PPC_DTPREL32 = 78
R_PPC_GOT_TLSGD16 = 79
R_PPC_GOT_TLSGD16_LO = 80
R_PPC_GOT_TLSGD16_HI = 81
R_PPC_GOT_TLSGD16_HA = 82
R_PPC_GOT_TLSLD16 = 83
R_PPC_GOT_TLSLD16_LO = 84
R_PPC_GOT_TLSLD16_HI = 85
R_PPC_GOT_TLSLD16_HA = 86
R_PPC_GOT_TPREL16 = 87
R_PPC_GOT_TPREL16_LO = 88
R_PPC_GOT_TPREL16_HI = 89
R_PPC_GOT_TPREL16_HA = 90
R_PPC_EMB_NADDR32 = 101
R_PPC_EMB_NADDR16 = 102
R_PPC_EMB_NADDR16_LO = 103
R_PPC_EMB_NADDR16_HI = 104
R_PPC_EMB_NADDR16_HA = 105
R_PPC_EMB_SDAI16 = 106
R_PPC_EMB_SDA2I16 = 107
R_PPC_EMB_SDA2REL = 108
R_PPC_EMB_SDA21 = 109
R_PPC_EMB_MRKREF = 110
R_PPC_EMB_RELSEC16 = 111
R_PPC_EMB_RELST_LO = 112
R_PPC_EMB_RELST_HI = 113
R_PPC_EMB_RELST_HA = 114
R_PPC_EMB_BIT_FLD = 115
R_PPC_EMB_RELSDA = 116
R_PPC64_ADDR32 = R_PPC_ADDR32
R_PPC64_ADDR16_LO = R_PPC_ADDR16_LO
R_PPC64_ADDR16_HA = R_PPC_ADDR16_HA
R_PPC64_REL24 = R_PPC_REL24
R_PPC64_GOT16_HA = R_PPC_GOT16_HA
R_PPC64_JMP_SLOT = R_PPC_JMP_SLOT
R_PPC64_TPREL16 = R_PPC_TPREL16
R_PPC64_ADDR64 = 38
R_PPC64_TOC16 = 47
R_PPC64_TOC16_LO = 48
R_PPC64_TOC16_HI = 49
R_PPC64_TOC16_HA = 50
R_PPC64_ADDR16_LO_DS = 57
R_PPC64_GOT16_LO_DS = 59
R_PPC64_TOC16_DS = 63
R_PPC64_TOC16_LO_DS = 64
R_PPC64_TLS = 67
R_PPC64_GOT_TPREL16_LO_DS = 88
R_PPC64_GOT_TPREL16_HA = 90
R_PPC64_REL16_LO = 250
R_PPC64_REL16_HI = 251
R_PPC64_REL16_HA = 252
R_SPARC_NONE = 0
R_SPARC_8 = 1
R_SPARC_16 = 2
R_SPARC_32 = 3
R_SPARC_DISP8 = 4
R_SPARC_DISP16 = 5
R_SPARC_DISP32 = 6
R_SPARC_WDISP30 = 7
R_SPARC_WDISP22 = 8
R_SPARC_HI22 = 9
R_SPARC_22 = 10
R_SPARC_13 = 11
R_SPARC_LO10 = 12
R_SPARC_GOT10 = 13
R_SPARC_GOT13 = 14
R_SPARC_GOT22 = 15
R_SPARC_PC10 = 16
R_SPARC_PC22 = 17
R_SPARC_WPLT30 = 18
R_SPARC_COPY = 19
R_SPARC_GLOB_DAT = 20
R_SPARC_JMP_SLOT = 21
R_SPARC_RELATIVE = 22
R_SPARC_UA32 = 23
R_SPARC_PLT32 = 24
R_SPARC_HIPLT22 = 25
R_SPARC_LOPLT10 = 26
R_SPARC_PCPLT32 = 27
R_SPARC_PCPLT22 = 28
R_SPARC_PCPLT10 = 29
R_SPARC_10 = 30
R_SPARC_11 = 31
R_SPARC_64 = 32
R_SPARC_OLO10 = 33
R_SPARC_HH22 = 34
R_SPARC_HM10 = 35
R_SPARC_LM22 = 36
R_SPARC_PC_HH22 = 37
R_SPARC_PC_HM10 = 38
R_SPARC_PC_LM22 = 39
R_SPARC_WDISP16 = 40
R_SPARC_WDISP19 = 41
R_SPARC_GLOB_JMP = 42
R_SPARC_7 = 43
R_SPARC_5 = 44
R_SPARC_6 = 45
R_SPARC_DISP64 = 46
R_SPARC_PLT64 = 47
R_SPARC_HIX22 = 48
R_SPARC_LOX10 = 49
R_SPARC_H44 = 50
R_SPARC_M44 = 51
R_SPARC_L44 = 52
R_SPARC_REGISTER = 53
R_SPARC_UA64 = 54
R_SPARC_UA16 = 55
R_390_NONE = 0
R_390_8 = 1
R_390_12 = 2
R_390_16 = 3
R_390_32 = 4
R_390_PC32 = 5
R_390_GOT12 = 6
R_390_GOT32 = 7
R_390_PLT32 = 8
R_390_COPY = 9
R_390_GLOB_DAT = 10
R_390_JMP_SLOT = 11
R_390_RELATIVE = 12
R_390_GOTOFF = 13
R_390_GOTPC = 14
R_390_GOT16 = 15
R_390_PC16 = 16
R_390_PC16DBL = 17
R_390_PLT16DBL = 18
R_390_PC32DBL = 19
R_390_PLT32DBL = 20
R_390_GOTPCDBL = 21
R_390_64 = 22
R_390_PC64 = 23
R_390_GOT64 = 24
R_390_PLT64 = 25
R_390_GOTENT = 26
R_390_GOTOFF16 = 27
R_390_GOTOFF64 = 28
R_390_GOTPLT12 = 29
R_390_GOTPLT16 = 30
R_390_GOTPLT32 = 31
R_390_GOTPLT64 = 32
R_390_GOTPLTENT = 33
R_390_GOTPLTOFF16 = 34
R_390_GOTPLTOFF32 = 35
R_390_GOTPLTOFF64 = 36
R_390_TLS_LOAD = 37
R_390_TLS_GDCALL = 38
R_390_TLS_LDCALL = 39
R_390_TLS_GD32 = 40
R_390_TLS_GD64 = 41
R_390_TLS_GOTIE12 = 42
R_390_TLS_GOTIE32 = 43
R_390_TLS_GOTIE64 = 44
R_390_TLS_LDM32 = 45
R_390_TLS_LDM64 = 46
R_390_TLS_IE32 = 47
R_390_TLS_IE64 = 48
R_390_TLS_IEENT = 49
R_390_TLS_LE32 = 50
R_390_TLS_LE64 = 51
R_390_TLS_LDO32 = 52
R_390_TLS_LDO64 = 53
R_390_TLS_DTPMOD = 54
R_390_TLS_DTPOFF = 55
R_390_TLS_TPOFF = 56
R_390_20 = 57
R_390_GOT20 = 58
R_390_GOTPLT20 = 59
R_390_TLS_GOTIE20 = 60
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
secsym *Symbol
}
/*
* 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 (
Iself bool
Nelfsym int = 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) {
Iself = true
if SysArch.InFamily(sys.AMD64, sys.ARM64, sys.MIPS64, sys.PPC64, sys.S390X) {
elfRelType = ".rela"
} else {
elfRelType = ".rel"
}
switch SysArch.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 SysArch.Family == sys.MIPS64 {
ehdr.flags = 0x20000000 /* MIPS 3 */
}
elf64 = true
ehdr.phoff = ELF64HDRSIZE /* Must be 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 SysArch.Family == sys.ARM {
// we use EABI on linux/arm, freebsd/arm, netbsd/arm.
if Headtype == objabi.Hlinux || Headtype == objabi.Hfreebsd || 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 SysArch.Family == sys.MIPS {
ehdr.flags = 0x50001004 /* MIPS 32 CPIC O32*/
}
fallthrough
default:
ehdr.phoff = ELF32HDRSIZE
/* Must be 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(e *ElfPhdr) {
if e.type_ == PT_LOAD {
fixElfPhdr(e)
}
Thearch.Lput(e.type_)
Thearch.Lput(e.flags)
Thearch.Vput(e.off)
Thearch.Vput(e.vaddr)
Thearch.Vput(e.paddr)
Thearch.Vput(e.filesz)
Thearch.Vput(e.memsz)
Thearch.Vput(e.align)
}
func elf32phdr(e *ElfPhdr) {
if e.type_ == PT_LOAD {
fixElfPhdr(e)
}
Thearch.Lput(e.type_)
Thearch.Lput(uint32(e.off))
Thearch.Lput(uint32(e.vaddr))
Thearch.Lput(uint32(e.paddr))
Thearch.Lput(uint32(e.filesz))
Thearch.Lput(uint32(e.memsz))
Thearch.Lput(e.flags)
Thearch.Lput(uint32(e.align))
}
func elf64shdr(e *ElfShdr) {
Thearch.Lput(e.name)
Thearch.Lput(e.type_)
Thearch.Vput(e.flags)
Thearch.Vput(e.addr)
Thearch.Vput(e.off)
Thearch.Vput(e.size)
Thearch.Lput(e.link)
Thearch.Lput(e.info)
Thearch.Vput(e.addralign)
Thearch.Vput(e.entsize)
}
func elf32shdr(e *ElfShdr) {
Thearch.Lput(e.name)
Thearch.Lput(e.type_)
Thearch.Lput(uint32(e.flags))
Thearch.Lput(uint32(e.addr))
Thearch.Lput(uint32(e.off))
Thearch.Lput(uint32(e.size))
Thearch.Lput(e.link)
Thearch.Lput(e.info)
Thearch.Lput(uint32(e.addralign))
Thearch.Lput(uint32(e.entsize))
}
func elfwriteshdrs() uint32 {
if elf64 {
for i := 0; i < int(ehdr.shnum); i++ {
elf64shdr(shdr[i])
}
return uint32(ehdr.shnum) * ELF64SHDRSIZE
}
for i := 0; i < int(ehdr.shnum); i++ {
elf32shdr(shdr[i])
}
return uint32(ehdr.shnum) * ELF32SHDRSIZE
}
func elfsetstring(s *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() uint32 {
if elf64 {
for i := 0; i < int(ehdr.phnum); i++ {
elf64phdr(phdr[i])
}
return uint32(ehdr.phnum) * ELF64PHDRSIZE
}
for i := 0; i < int(ehdr.phnum); i++ {
elf32phdr(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() uint32 {
for i := 0; i < EI_NIDENT; i++ {
Cput(ehdr.ident[i])
}
Thearch.Wput(ehdr.type_)
Thearch.Wput(ehdr.machine)
Thearch.Lput(ehdr.version)
Thearch.Vput(ehdr.entry)
Thearch.Vput(ehdr.phoff)
Thearch.Vput(ehdr.shoff)
Thearch.Lput(ehdr.flags)
Thearch.Wput(ehdr.ehsize)
Thearch.Wput(ehdr.phentsize)
Thearch.Wput(ehdr.phnum)
Thearch.Wput(ehdr.shentsize)
Thearch.Wput(ehdr.shnum)
Thearch.Wput(ehdr.shstrndx)
return ELF64HDRSIZE
}
func elf32writehdr() uint32 {
for i := 0; i < EI_NIDENT; i++ {
Cput(ehdr.ident[i])
}
Thearch.Wput(ehdr.type_)
Thearch.Wput(ehdr.machine)
Thearch.Lput(ehdr.version)
Thearch.Lput(uint32(ehdr.entry))
Thearch.Lput(uint32(ehdr.phoff))
Thearch.Lput(uint32(ehdr.shoff))
Thearch.Lput(ehdr.flags)
Thearch.Wput(ehdr.ehsize)
Thearch.Wput(ehdr.phentsize)
Thearch.Wput(ehdr.phnum)
Thearch.Wput(ehdr.shentsize)
Thearch.Wput(ehdr.shnum)
Thearch.Wput(ehdr.shstrndx)
return ELF32HDRSIZE
}
func elfwritehdr() uint32 {
if elf64 {
return elf64writehdr()
}
return elf32writehdr()
}
/* 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 *Symbol, tag int, val uint64) {
if elf64 {
Adduint64(ctxt, s, uint64(tag))
Adduint64(ctxt, s, val)
} else {
Adduint32(ctxt, s, uint32(tag))
Adduint32(ctxt, s, uint32(val))
}
}
func elfwritedynentsym(ctxt *Link, s *Symbol, tag int, t *Symbol) {
Elfwritedynentsymplus(ctxt, s, tag, t, 0)
}
func Elfwritedynentsymplus(ctxt *Link, s *Symbol, tag int, t *Symbol, add int64) {
if elf64 {
Adduint64(ctxt, s, uint64(tag))
} else {
Adduint32(ctxt, s, uint32(tag))
}
Addaddrplus(ctxt, s, t, add)
}
func elfwritedynentsymsize(ctxt *Link, s *Symbol, tag int, t *Symbol) {
if elf64 {
Adduint64(ctxt, s, uint64(tag))
} else {
Adduint32(ctxt, s, uint32(tag))
}
addsize(ctxt, s, 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() int {
sh := elfshname(".interp")
Cseek(int64(sh.off))
coutbuf.WriteString(interp)
Cput(0)
return int(sh.size)
}
func elfnote(sh *ElfShdr, startva uint64, resoff uint64, sz int, alloc bool) int {
n := 3*4 + uint64(sz) + resoff%4
sh.type_ = SHT_NOTE
if alloc {
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(str string, namesz uint32, descsz uint32, tag uint32) *ElfShdr {
sh := elfshname(str)
// Write Elf_Note header.
Cseek(int64(sh.off))
Thearch.Lput(namesz)
Thearch.Lput(descsz)
Thearch.Lput(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, true)
}
func elfwritenetbsdsig() int {
// Write Elf_Note header.
sh := elfwritenotehdr(".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.
Cwrite(ELF_NOTE_NETBSD_NAME)
Cput(0)
Thearch.Lput(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, true)
}
func elfwriteopenbsdsig() int {
// Write Elf_Note header.
sh := elfwritenotehdr(".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.
Cwrite(ELF_NOTE_OPENBSD_NAME)
Thearch.Lput(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, true)
}
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, true)
}
func elfwritebuildinfo() int {
sh := elfwritenotehdr(".note.gnu.build-id", ELF_NOTE_BUILDINFO_NAMESZ, uint32(len(buildinfo)), ELF_NOTE_BUILDINFO_TAG)
if sh == nil {
return 0
}
Cwrite(ELF_NOTE_BUILDINFO_NAME)
Cwrite(buildinfo)
var zero = make([]byte, 4)
Cwrite(zero[:int(Rnd(int64(len(buildinfo)), 4)-int64(len(buildinfo)))])
return int(sh.size)
}
func elfwritegobuildid() int {
sh := elfwritenotehdr(".note.go.buildid", uint32(len(ELF_NOTE_GO_NAME)), uint32(len(*flagBuildid)), ELF_NOTE_GOBUILDID_TAG)
if sh == nil {
return 0
}
Cwrite(ELF_NOTE_GO_NAME)
Cwrite([]byte(*flagBuildid))
var zero = make([]byte, 4)
Cwrite(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
lib.aux = aux
return aux
}
func elfdynhash(ctxt *Link) {
if !Iself {
return
}
nsym := Nelfsym
s := ctxt.Syms.Lookup(".hash", 0)
s.Type = SELFROSECT
s.Attr |= AttrReachable
i := nsym
nbucket := 1
for i > 0 {
nbucket++
i >>= 1
}
var needlib *Elflib
need := make([]*Elfaux, nsym)
chain := make([]uint32, nsym)
buckets := make([]uint32, nbucket)
var b int
for _, sy := range ctxt.Syms.Allsym {
if sy.Dynid <= 0 {
continue
}
if sy.Dynimpvers != "" {
need[sy.Dynid] = addelflib(&needlib, sy.Dynimplib, sy.Dynimpvers)
}
name := sy.Extname
hc := elfhash(name)
b = int(hc % uint32(nbucket))
chain[sy.Dynid] = buckets[b]
buckets[b] = uint32(sy.Dynid)
}
// s390x (ELF64) hash table entries are 8 bytes
if SysArch.Family == sys.S390X {
Adduint64(ctxt, s, uint64(nbucket))
Adduint64(ctxt, s, uint64(nsym))
for i := 0; i < nbucket; i++ {
Adduint64(ctxt, s, uint64(buckets[i]))
}
for i := 0; i < nsym; i++ {
Adduint64(ctxt, s, uint64(chain[i]))
}
} else {
Adduint32(ctxt, s, uint32(nbucket))
Adduint32(ctxt, s, uint32(nsym))
for i := 0; i < nbucket; i++ {
Adduint32(ctxt, s, buckets[i])
}
for i := 0; i < nsym; i++ {
Adduint32(ctxt, s, chain[i])
}
}
// version symbols
dynstr := ctxt.Syms.Lookup(".dynstr", 0)
s = ctxt.Syms.Lookup(".gnu.version_r", 0)
i = 2
nfile := 0
var j int
var x *Elfaux
for l := needlib; l != nil; l = l.next {
nfile++
// header
Adduint16(ctxt, s, 1) // table version
j = 0
for x = l.aux; x != nil; x = x.next {
j++
}
Adduint16(ctxt, s, uint16(j)) // aux count
Adduint32(ctxt, s, uint32(Addstring(dynstr, l.file))) // file string offset
Adduint32(ctxt, s, 16) // offset from header to first aux
if l.next != nil {
Adduint32(ctxt, s, 16+uint32(j)*16) // offset from this header to next
} else {
Adduint32(ctxt, s, 0)
}
for x = l.aux; x != nil; x = x.next {
x.num = i
i++
// aux struct
Adduint32(ctxt, s, elfhash(x.vers)) // hash
Adduint16(ctxt, s, 0) // flags
Adduint16(ctxt, s, uint16(x.num)) // other - index we refer to this by
Adduint32(ctxt, s, uint32(Addstring(dynstr, x.vers))) // version string offset
if x.next != nil {
Adduint32(ctxt, s, 16) // offset from this aux to next
} else {
Adduint32(ctxt, s, 0)
}
}
}
// version references
s = ctxt.Syms.Lookup(".gnu.version", 0)
for i := 0; i < nsym; i++ {
if i == 0 {
Adduint16(ctxt, s, 0) // first entry - no symbol
} else if need[i] == nil {
Adduint16(ctxt, s, 1) // global
} else {
Adduint16(ctxt, s, uint16(need[i].num))
}
}
s = ctxt.Syms.Lookup(".dynamic", 0)
elfverneed = nfile
if elfverneed != 0 {
elfwritedynentsym(ctxt, s, DT_VERNEED, ctxt.Syms.Lookup(".gnu.version_r", 0))
Elfwritedynent(ctxt, s, DT_VERNEEDNUM, uint64(nfile))
elfwritedynentsym(ctxt, s, DT_VERSYM, ctxt.Syms.Lookup(".gnu.version", 0))
}
sy := ctxt.Syms.Lookup(elfRelType+".plt", 0)
if sy.Size > 0 {
if elfRelType == ".rela" {
Elfwritedynent(ctxt, s, DT_PLTREL, DT_RELA)
} else {
Elfwritedynent(ctxt, s, DT_PLTREL, DT_REL)
}
elfwritedynentsymsize(ctxt, s, DT_PLTRELSZ, sy)
elfwritedynentsym(ctxt, s, DT_JMPREL, sy)
}
Elfwritedynent(ctxt, s, DT_NULL, 0)
}
func elfphload(seg *Segment) *ElfPhdr {
ph := newElfPhdr()
ph.type_ = PT_LOAD
if seg.Rwx&4 != 0 {
ph.flags |= PF_R
}
if seg.Rwx&2 != 0 {
ph.flags |= PF_W
}
if seg.Rwx&1 != 0 {
ph.flags |= PF_X
}
ph.vaddr = seg.Vaddr
ph.paddr = seg.Vaddr
ph.memsz = seg.Length
ph.off = seg.Fileoff
ph.filesz = seg.Filelen
ph.align = uint64(*FlagRound)
return ph
}
func elfphrelro(seg *Segment) {
ph := newElfPhdr()
ph.type_ = PT_GNU_RELRO
ph.vaddr = seg.Vaddr
ph.paddr = seg.Vaddr
ph.memsz = seg.Length
ph.off = seg.Fileoff
ph.filesz = seg.Filelen
ph.align = uint64(*FlagRound)
}
func elfshname(name string) *ElfShdr {
var off int
var sh *ElfShdr
for i := 0; i < nelfstr; i++ {
if name == elfstr[i].s {
off = elfstr[i].off
for i = 0; i < int(ehdr.shnum); i++ {
sh = shdr[i]
if sh.name == uint32(off) {
return sh
}
}
sh = newElfShdr(int64(off))
return sh
}
}
Exitf("cannot find elf name %s", name)
return nil
}
// Create an ElfShdr for the section with name.
// Create a duplicate if one already exists with that name
func elfshnamedup(name string) *ElfShdr {
var off int
var sh *ElfShdr
for i := 0; i < nelfstr; i++ {
if name == elfstr[i].s {
off = elfstr[i].off
sh = newElfShdr(int64(off))
return sh
}
}
Errorf(nil, "cannot find elf name %s", name)
errorexit()
return nil
}
func elfshalloc(sect *Section) *ElfShdr {
sh := elfshname(sect.Name)
sect.Elfsect = sh
return sh
}
func elfshbits(sect *Section) *ElfShdr {
var sh *ElfShdr
if sect.Name == ".text" {
if sect.Elfsect == nil {
sect.Elfsect = elfshnamedup(sect.Name)
}
sh = sect.Elfsect
} else {
sh = elfshalloc(sect)
}
// If this section has already been set up as a note, we assume type_ and
// flags are already correct, but the other fields still need filling in.
if sh.type_ == SHT_NOTE {
if Linkmode != LinkExternal {
// TODO(mwhudson): the approach here will work OK when
// linking internally for notes that we want to be included
// in a loadable segment (e.g. the abihash note) but not for
// notes that we do not want to be mapped (e.g. the package
// list note). The real fix is probably to define new values
// for Symbol.Type corresponding to mapped and unmapped notes
// and handle them in dodata().
Errorf(nil, "sh.type_ == SHT_NOTE in elfshbits when linking internally")
}
sh.addralign = uint64(sect.Align)
sh.size = sect.Length
sh.off = sect.Seg.Fileoff + sect.Vaddr - sect.Seg.Vaddr
return sh
}
if sh.type_ > 0 {
return sh
}
if sect.Vaddr < sect.Seg.Vaddr+sect.Seg.Filelen {
sh.type_ = SHT_PROGBITS
} else {
sh.type_ = SHT_NOBITS
}
sh.flags = SHF_ALLOC
if sect.Rwx&1 != 0 {
sh.flags |= SHF_EXECINSTR
}
if sect.Rwx&2 != 0 {
sh.flags |= SHF_WRITE
}
if sect.Name == ".tbss" {
sh.flags |= SHF_TLS
sh.type_ = SHT_NOBITS
}
if strings.HasPrefix(sect.Name, ".debug") {
sh.flags = 0
}
if Linkmode != LinkExternal {
sh.addr = sect.Vaddr
}
sh.addralign = uint64(sect.Align)
sh.size = sect.Length
if sect.Name != ".tbss" {
sh.off = sect.Seg.Fileoff + sect.Vaddr - sect.Seg.Vaddr
}
return sh
}
func elfshreloc(sect *Section) *ElfShdr {
// If main section is SHT_NOBITS, nothing to relocate.
// Also nothing to relocate in .shstrtab or notes.
if sect.Vaddr >= sect.Seg.Vaddr+sect.Seg.Filelen {
return nil
}
if sect.Name == ".shstrtab" || sect.Name == ".tbss" {
return nil
}
if sect.Elfsect.type_ == SHT_NOTE {
return nil
}
var typ int
if elfRelType == ".rela" {
typ = SHT_RELA
} else {
typ = SHT_REL
}
sh := elfshname(elfRelType + sect.Name)
// There could be multiple text sections but each needs
// its own .rela.text.
if sect.Name == ".text" {
if sh.info != 0 && sh.info != uint32(sect.Elfsect.shnum) {
sh = elfshnamedup(elfRelType + sect.Name)
}
}
sh.type_ = uint32(typ)
sh.entsize = uint64(SysArch.RegSize) * 2
if typ == SHT_RELA {
sh.entsize += uint64(SysArch.RegSize)
}
sh.link = uint32(elfshname(".symtab").shnum)
sh.info = uint32(sect.Elfsect.shnum)
sh.off = sect.Reloff
sh.size = sect.Rellen
sh.addralign = uint64(SysArch.RegSize)
return sh
}
func elfrelocsect(ctxt *Link, sect *Section, syms []*Symbol) {
// If main section is SHT_NOBITS, nothing to relocate.
// Also nothing to relocate in .shstrtab.
if sect.Vaddr >= sect.Seg.Vaddr+sect.Seg.Filelen {
return
}
if sect.Name == ".shstrtab" {
return
}
sect.Reloff = uint64(coutbuf.Offset())
for i, s := range syms {
if !s.Attr.Reachable() {
continue
}
if uint64(s.Value) >= sect.Vaddr {
syms = syms[i:]
break
}
}
eaddr := int32(sect.Vaddr + sect.Length)
for _, sym := range syms {
if !sym.Attr.Reachable() {
continue
}
if sym.Value >= int64(eaddr) {
break
}
for ri := 0; ri < len(sym.R); ri++ {
r := &sym.R[ri]
if r.Done != 0 {
continue
}
if r.Xsym == nil {
Errorf(sym, "missing xsym in relocation")
continue
}
if r.Xsym.ElfsymForReloc() == 0 {
Errorf(sym, "reloc %d to non-elf symbol %s (outer=%s) %d", r.Type, r.Sym.Name, r.Xsym.Name, r.Sym.Type)
}
if !r.Xsym.Attr.Reachable() {
Errorf(sym, "unreachable reloc %v target %v", r.Type, r.Xsym.Name)
}
if Thearch.Elfreloc1(ctxt, r, int64(uint64(sym.Value+int64(r.Off))-sect.Vaddr)) < 0 {
Errorf(sym, "unsupported obj reloc %d/%d to %s", r.Type, r.Siz, r.Sym.Name)
}
}
}
sect.Rellen = uint64(coutbuf.Offset()) - sect.Reloff
}
func Elfemitreloc(ctxt *Link) {
for coutbuf.Offset()&7 != 0 {
Cput(0)
}
for _, sect := range Segtext.Sections {
if sect.Name == ".text" {
elfrelocsect(ctxt, sect, ctxt.Textp)
} else {
elfrelocsect(ctxt, sect, datap)
}
}
for _, sect := range Segrodata.Sections {
elfrelocsect(ctxt, sect, datap)
}
for _, sect := range Segrelrodata.Sections {
elfrelocsect(ctxt, sect, datap)
}
for _, sect := range Segdata.Sections {
elfrelocsect(ctxt, sect, datap)
}
for _, sect := range Segdwarf.Sections {
elfrelocsect(ctxt, sect, dwarfp)
}
}
func addgonote(ctxt *Link, sectionName string, tag uint32, desc []byte) {
s := ctxt.Syms.Lookup(sectionName, 0)
s.Attr |= AttrReachable
s.Type = SELFROSECT
// namesz
Adduint32(ctxt, s, uint32(len(ELF_NOTE_GO_NAME)))
// descsz
Adduint32(ctxt, s, uint32(len(desc)))
// tag
Adduint32(ctxt, s, tag)
// name + padding
s.P = append(s.P, ELF_NOTE_GO_NAME...)
for len(s.P)%4 != 0 {
s.P = append(s.P, 0)
}
// desc + padding
s.P = append(s.P, desc...)
for len(s.P)%4 != 0 {
s.P = append(s.P, 0)
}
s.Size = int64(len(s.P))
}
func (ctxt *Link) doelf() {
if !Iself {
return
}
/* predefine strings we need for section headers */
shstrtab := ctxt.Syms.Lookup(".shstrtab", 0)
shstrtab.Type = SELFROSECT
shstrtab.Attr |= AttrReachable
Addstring(shstrtab, "")
Addstring(shstrtab, ".text")
Addstring(shstrtab, ".noptrdata")
Addstring(shstrtab, ".data")
Addstring(shstrtab, ".bss")
Addstring(shstrtab, ".noptrbss")
// generate .tbss section for dynamic internal linker or external
// linking, so that various binutils could correctly calculate
// PT_TLS size. See https://golang.org/issue/5200.
if !*FlagD || Linkmode == LinkExternal {
Addstring(shstrtab, ".tbss")
}
if Headtype == objabi.Hnetbsd {
Addstring(shstrtab, ".note.netbsd.ident")
}
if Headtype == objabi.Hopenbsd {
Addstring(shstrtab, ".note.openbsd.ident")
}
if len(buildinfo) > 0 {
Addstring(shstrtab, ".note.gnu.build-id")
}
if *flagBuildid != "" {
Addstring(shstrtab, ".note.go.buildid")
}
Addstring(shstrtab, ".elfdata")
Addstring(shstrtab, ".rodata")
// See the comment about data.rel.ro.FOO section names in data.go.
relro_prefix := ""
if UseRelro() {
Addstring(shstrtab, ".data.rel.ro")
relro_prefix = ".data.rel.ro"
}
Addstring(shstrtab, relro_prefix+".typelink")
Addstring(shstrtab, relro_prefix+".itablink")
Addstring(shstrtab, relro_prefix+".gosymtab")
Addstring(shstrtab, relro_prefix+".gopclntab")
if Linkmode == LinkExternal {
*FlagD = true
Addstring(shstrtab, elfRelType+".text")
Addstring(shstrtab, elfRelType+".rodata")
Addstring(shstrtab, elfRelType+relro_prefix+".typelink")
Addstring(shstrtab, elfRelType+relro_prefix+".itablink")
Addstring(shstrtab, elfRelType+relro_prefix+".gosymtab")
Addstring(shstrtab, elfRelType+relro_prefix+".gopclntab")
Addstring(shstrtab, elfRelType+".noptrdata")
Addstring(shstrtab, elfRelType+".data")
if UseRelro() {
Addstring(shstrtab, elfRelType+".data.rel.ro")
}
// add a .note.GNU-stack section to mark the stack as non-executable
Addstring(shstrtab, ".note.GNU-stack")
if Buildmode == BuildmodeShared {
Addstring(shstrtab, ".note.go.abihash")
Addstring(shstrtab, ".note.go.pkg-list")
Addstring(shstrtab, ".note.go.deps")
}
}
hasinitarr := *FlagLinkshared
/* shared library initializer */
switch Buildmode {
case BuildmodeCArchive, BuildmodeCShared, BuildmodeShared, BuildmodePlugin:
hasinitarr = true
}
if hasinitarr {
Addstring(shstrtab, ".init_array")
Addstring(shstrtab, elfRelType+".init_array")
}
if !*FlagS {
Addstring(shstrtab, ".symtab")
Addstring(shstrtab, ".strtab")
dwarfaddshstrings(ctxt, shstrtab)
}
Addstring(shstrtab, ".shstrtab")
if !*FlagD { /* -d suppresses dynamic loader format */
Addstring(shstrtab, ".interp")
Addstring(shstrtab, ".hash")
Addstring(shstrtab, ".got")
if SysArch.Family == sys.PPC64 {
Addstring(shstrtab, ".glink")
}
Addstring(shstrtab, ".got.plt")
Addstring(shstrtab, ".dynamic")
Addstring(shstrtab, ".dynsym")
Addstring(shstrtab, ".dynstr")
Addstring(shstrtab, elfRelType)
Addstring(shstrtab, elfRelType+".plt")
Addstring(shstrtab, ".plt")
Addstring(shstrtab, ".gnu.version")
Addstring(shstrtab, ".gnu.version_r")
/* dynamic symbol table - first entry all zeros */
s := ctxt.Syms.Lookup(".dynsym", 0)
s.Type = SELFROSECT
s.Attr |= AttrReachable
if elf64 {
s.Size += ELF64SYMSIZE
} else {
s.Size += ELF32SYMSIZE
}
/* dynamic string table */
s = ctxt.Syms.Lookup(".dynstr", 0)
s.Type = SELFROSECT
s.Attr |= AttrReachable
if s.Size == 0 {
Addstring(s, "")
}
dynstr := s
/* relocation table */
s = ctxt.Syms.Lookup(elfRelType, 0)
s.Attr |= AttrReachable
s.Type = SELFROSECT
/* global offset table */
s = ctxt.Syms.Lookup(".got", 0)
s.Attr |= AttrReachable
s.Type = SELFGOT // writable
/* ppc64 glink resolver */
if SysArch.Family == sys.PPC64 {
s := ctxt.Syms.Lookup(".glink", 0)
s.Attr |= AttrReachable
s.Type = SELFRXSECT
}
/* hash */
s = ctxt.Syms.Lookup(".hash", 0)
s.Attr |= AttrReachable
s.Type = SELFROSECT
s = ctxt.Syms.Lookup(".got.plt", 0)
s.Attr |= AttrReachable
s.Type = SELFSECT // writable
s = ctxt.Syms.Lookup(".plt", 0)
s.Attr |= AttrReachable
if SysArch.Family == sys.PPC64 {
// In the ppc64 ABI, .plt is a data section
// written by the dynamic linker.
s.Type = SELFSECT
} else {
s.Type = SELFRXSECT
}
Thearch.Elfsetupplt(ctxt)
s = ctxt.Syms.Lookup(elfRelType+".plt", 0)
s.Attr |= AttrReachable
s.Type = SELFROSECT
s = ctxt.Syms.Lookup(".gnu.version", 0)
s.Attr |= AttrReachable
s.Type = SELFROSECT
s = ctxt.Syms.Lookup(".gnu.version_r", 0)
s.Attr |= AttrReachable
s.Type = SELFROSECT
/* define dynamic elf table */
s = ctxt.Syms.Lookup(".dynamic", 0)
s.Attr |= AttrReachable
s.Type = SELFSECT // writable
/*
* .dynamic table
*/
elfwritedynentsym(ctxt, s, DT_HASH, ctxt.Syms.Lookup(".hash", 0))
elfwritedynentsym(ctxt, s, DT_SYMTAB, ctxt.Syms.Lookup(".dynsym", 0))
if elf64 {
Elfwritedynent(ctxt, s, DT_SYMENT, ELF64SYMSIZE)
} else {
Elfwritedynent(ctxt, s, DT_SYMENT, ELF32SYMSIZE)
}
elfwritedynentsym(ctxt, s, DT_STRTAB, ctxt.Syms.Lookup(".dynstr", 0))
elfwritedynentsymsize(ctxt, s, DT_STRSZ, ctxt.Syms.Lookup(".dynstr", 0))
if elfRelType == ".rela" {
elfwritedynentsym(ctxt, s, DT_RELA, ctxt.Syms.Lookup(".rela", 0))
elfwritedynentsymsize(ctxt, s, DT_RELASZ, ctxt.Syms.Lookup(".rela", 0))
Elfwritedynent(ctxt, s, DT_RELAENT, ELF64RELASIZE)
} else {
elfwritedynentsym(ctxt, s, DT_REL, ctxt.Syms.Lookup(".rel", 0))
elfwritedynentsymsize(ctxt, s, DT_RELSZ, ctxt.Syms.Lookup(".rel", 0))
Elfwritedynent(ctxt, s, DT_RELENT, ELF32RELSIZE)
}
if rpath.val != "" {
Elfwritedynent(ctxt, s, DT_RUNPATH, uint64(Addstring(dynstr, rpath.val)))
}
if SysArch.Family == sys.PPC64 {
elfwritedynentsym(ctxt, s, DT_PLTGOT, ctxt.Syms.Lookup(".plt", 0))
} else if SysArch.Family == sys.S390X {
elfwritedynentsym(ctxt, s, DT_PLTGOT, ctxt.Syms.Lookup(".got", 0))
} else {
elfwritedynentsym(ctxt, s, DT_PLTGOT, ctxt.Syms.Lookup(".got.plt", 0))
}
if SysArch.Family == sys.PPC64 {
Elfwritedynent(ctxt, s, DT_PPC64_OPT, 0)
}
// Solaris dynamic linker can't handle an empty .rela.plt if
// DT_JMPREL is emitted so we have to defer generation of DT_PLTREL,
// DT_PLTRELSZ, and DT_JMPREL dynamic entries until after we know the
// size of .rel(a).plt section.
Elfwritedynent(ctxt, s, DT_DEBUG, 0)
}
if Buildmode == BuildmodeShared {
// The go.link.abihashbytes symbol will be pointed at the appropriate
// part of the .note.go.abihash section in data.go:func address().
s := ctxt.Syms.Lookup("go.link.abihashbytes", 0)
s.Attr |= AttrLocal
s.Type = SRODATA
s.Attr |= AttrSpecial
s.Attr |= AttrReachable
s.Size = int64(sha1.Size)
sort.Sort(byPkg(ctxt.Library))
h := sha1.New()
for _, l := range ctxt.Library {
io.WriteString(h, l.hash)
}
addgonote(ctxt, ".note.go.abihash", ELF_NOTE_GOABIHASH_TAG, h.Sum([]byte{}))
addgonote(ctxt, ".note.go.pkg-list", ELF_NOTE_GOPKGLIST_TAG, pkglistfornote)
var deplist []string
for _, shlib := range ctxt.Shlibs {
deplist = append(deplist, filepath.Base(shlib.Path))
}
addgonote(ctxt, ".note.go.deps", ELF_NOTE_GODEPS_TAG, []byte(strings.Join(deplist, "\n")))
}
if Linkmode == LinkExternal && *flagBuildid != "" {
addgonote(ctxt, ".note.go.buildid", ELF_NOTE_GOBUILDID_TAG, []byte(*flagBuildid))
}
}
// Do not write DT_NULL. elfdynhash will finish it.
func shsym(sh *ElfShdr, s *Symbol) {
addr := Symaddr(s)
if sh.flags&SHF_ALLOC != 0 {
sh.addr = uint64(addr)
}
sh.off = uint64(datoff(s, addr))
sh.size = uint64(s.Size)
}
func phsh(ph *ElfPhdr, sh *ElfShdr) {
ph.vaddr = sh.addr
ph.paddr = ph.vaddr
ph.off = sh.off
ph.filesz = sh.size
ph.memsz = sh.size
ph.align = sh.addralign
}
func Asmbelfsetup() {
/* This null SHdr must appear before all others */
elfshname("")
for _, sect := range Segtext.Sections {
// There could be multiple .text sections. Instead check the Elfsect
// field to determine if already has an ElfShdr and if not, create one.
if sect.Name == ".text" {
if sect.Elfsect == nil {
sect.Elfsect = elfshnamedup(sect.Name)
}
} else {
elfshalloc(sect)
}
}
for _, sect := range Segrodata.Sections {
elfshalloc(sect)
}
for _, sect := range Segrelrodata.Sections {
elfshalloc(sect)
}
for _, sect := range Segdata.Sections {
elfshalloc(sect)
}
for _, sect := range Segdwarf.Sections {
elfshalloc(sect)
}
}
func Asmbelf(ctxt *Link, symo int64) {
eh := getElfEhdr()
switch SysArch.Family {
default:
Exitf("unknown architecture in asmbelf: %v", SysArch.Family)
case sys.MIPS, sys.MIPS64:
eh.machine = EM_MIPS
case sys.ARM:
eh.machine = EM_ARM
case sys.AMD64:
eh.machine = EM_X86_64
case sys.ARM64:
eh.machine = EM_AARCH64
case sys.I386:
eh.machine = EM_386
case sys.PPC64:
eh.machine = EM_PPC64
case sys.S390X:
eh.machine = EM_S390
}
elfreserve := int64(ELFRESERVE)
numtext := int64(0)
for _, sect := range Segtext.Sections {
if sect.Name == ".text" {
numtext++
}
}
// If there are multiple text sections, extra space is needed
// in the elfreserve for the additional .text and .rela.text
// section headers. It can handle 4 extra now. Headers are
// 64 bytes.
if numtext > 4 {
elfreserve += elfreserve + numtext*64*2
}
startva := *FlagTextAddr - int64(HEADR)
resoff := elfreserve
var pph *ElfPhdr
var pnote *ElfPhdr
if Linkmode == LinkExternal {
/* skip program headers */
eh.phoff = 0
eh.phentsize = 0
if Buildmode == BuildmodeShared {
sh := elfshname(".note.go.pkg-list")
sh.type_ = SHT_NOTE
sh = elfshname(".note.go.abihash")
sh.type_ = SHT_NOTE
sh.flags = SHF_ALLOC
sh = elfshname(".note.go.deps")
sh.type_ = SHT_NOTE
}
if *flagBuildid != "" {
sh := elfshname(".note.go.buildid")
sh.type_ = SHT_NOTE
sh.flags = SHF_ALLOC
}
goto elfobj
}
/* program header info */
pph = newElfPhdr()
pph.type_ = PT_PHDR
pph.flags = PF_R
pph.off = uint64(eh.ehsize)
pph.vaddr = uint64(*FlagTextAddr) - uint64(HEADR) + pph.off
pph.paddr = uint64(*FlagTextAddr) - uint64(HEADR) + pph.off
pph.align = uint64(*FlagRound)
/*
* PHDR must be in a loaded segment. Adjust the text
* segment boundaries downwards to include it.
* Except on NaCl where it must not be loaded.
*/
if Headtype != objabi.Hnacl {
o := int64(Segtext.Vaddr - pph.vaddr)
Segtext.Vaddr -= uint64(o)
Segtext.Length += uint64(o)
o = int64(Segtext.Fileoff - pph.off)
Segtext.Fileoff -= uint64(o)
Segtext.Filelen += uint64(o)
}
if !*FlagD { /* -d suppresses dynamic loader format */
/* interpreter */
sh := elfshname(".interp")
sh.type_ = SHT_PROGBITS
sh.flags = SHF_ALLOC
sh.addralign = 1
if interpreter == "" {
switch Headtype {
case objabi.Hlinux:
interpreter = Thearch.Linuxdynld
case objabi.Hfreebsd:
interpreter = Thearch.Freebsddynld
case objabi.Hnetbsd:
interpreter = Thearch.Netbsddynld
case objabi.Hopenbsd:
interpreter = Thearch.Openbsddynld
case objabi.Hdragonfly:
interpreter = Thearch.Dragonflydynld
case objabi.Hsolaris:
interpreter = Thearch.Solarisdynld
}
}
resoff -= int64(elfinterp(sh, uint64(startva), uint64(resoff), interpreter))
ph := newElfPhdr()
ph.type_ = PT_INTERP
ph.flags = PF_R
phsh(ph, sh)
}
pnote = nil
if Headtype == objabi.Hnetbsd || Headtype == objabi.Hopenbsd {
var sh *ElfShdr
switch Headtype {
case objabi.Hnetbsd:
sh = elfshname(".note.netbsd.ident")
resoff -= int64(elfnetbsdsig(sh, uint64(startva), uint64(resoff)))
case objabi.Hopenbsd:
sh = elfshname(".note.openbsd.ident")
resoff -= int64(elfopenbsdsig(sh, uint64(startva), uint64(resoff)))
}
pnote = newElfPhdr()
pnote.type_ = PT_NOTE
pnote.flags = PF_R
phsh(pnote, sh)
}
if len(buildinfo) > 0 {
sh := elfshname(".note.gnu.build-id")
resoff -= int64(elfbuildinfo(sh, uint64(startva), uint64(resoff)))
if pnote == nil {
pnote = newElfPhdr()
pnote.type_ = PT_NOTE
pnote.flags = PF_R
}
phsh(pnote, sh)
}
if *flagBuildid != "" {
sh := elfshname(".note.go.buildid")
resoff -= int64(elfgobuildid(sh, uint64(startva), uint64(resoff)))
pnote := newElfPhdr()
pnote.type_ = PT_NOTE
pnote.flags = PF_R
phsh(pnote, sh)
}
// Additions to the reserved area must be above this line.
elfphload(&Segtext)
if len(Segrodata.Sections) > 0 {
elfphload(&Segrodata)
}
if len(Segrelrodata.Sections) > 0 {
elfphload(&Segrelrodata)
elfphrelro(&Segrelrodata)
}
elfphload(&Segdata)
/* Dynamic linking sections */
if !*FlagD {
sh := elfshname(".dynsym")
sh.type_ = SHT_DYNSYM
sh.flags = SHF_ALLOC
if elf64 {
sh.entsize = ELF64SYMSIZE
} else {
sh.entsize = ELF32SYMSIZE
}
sh.addralign = uint64(SysArch.RegSize)
sh.link = uint32(elfshname(".dynstr").shnum)
// sh->info = index of first non-local symbol (number of local symbols)
shsym(sh, ctxt.Syms.Lookup(".dynsym", 0))
sh = elfshname(".dynstr")
sh.type_ = SHT_STRTAB
sh.flags = SHF_ALLOC
sh.addralign = 1
shsym(sh, ctxt.Syms.Lookup(".dynstr", 0))
if elfverneed != 0 {
sh := elfshname(".gnu.version")
sh.type_ = SHT_GNU_VERSYM
sh.flags = SHF_ALLOC
sh.addralign = 2
sh.link = uint32(elfshname(".dynsym").shnum)
sh.entsize = 2
shsym(sh, ctxt.Syms.Lookup(".gnu.version", 0))
sh = elfshname(".gnu.version_r")
sh.type_ = SHT_GNU_VERNEED
sh.flags = SHF_ALLOC
sh.addralign = uint64(SysArch.RegSize)
sh.info = uint32(elfverneed)
sh.link = uint32(elfshname(".dynstr").shnum)
shsym(sh, ctxt.Syms.Lookup(".gnu.version_r", 0))
}
if elfRelType == ".rela" {
sh := elfshname(".rela.plt")
sh.type_ = SHT_RELA
sh.flags = SHF_ALLOC
sh.entsize = ELF64RELASIZE
sh.addralign = uint64(SysArch.RegSize)
sh.link = uint32(elfshname(".dynsym").shnum)
sh.info = uint32(elfshname(".plt").shnum)
shsym(sh, ctxt.Syms.Lookup(".rela.plt", 0))
sh = elfshname(".rela")
sh.type_ = SHT_RELA
sh.flags = SHF_ALLOC
sh.entsize = ELF64RELASIZE
sh.addralign = 8
sh.link = uint32(elfshname(".dynsym").shnum)
shsym(sh, ctxt.Syms.Lookup(".rela", 0))
} else {
sh := elfshname(".rel.plt")
sh.type_ = SHT_REL
sh.flags = SHF_ALLOC
sh.entsize = ELF32RELSIZE
sh.addralign = 4
sh.link = uint32(elfshname(".dynsym").shnum)
shsym(sh, ctxt.Syms.Lookup(".rel.plt", 0))
sh = elfshname(".rel")
sh.type_ = SHT_REL
sh.flags = SHF_ALLOC
sh.entsize = ELF32RELSIZE
sh.addralign = 4
sh.link = uint32(elfshname(".dynsym").shnum)
shsym(sh, ctxt.Syms.Lookup(".rel", 0))
}
if eh.machine == EM_PPC64 {
sh := elfshname(".glink")
sh.type_ = SHT_PROGBITS
sh.flags = SHF_ALLOC + SHF_EXECINSTR
sh.addralign = 4
shsym(sh, ctxt.Syms.Lookup(".glink", 0))
}
sh = elfshname(".plt")
sh.type_ = SHT_PROGBITS
sh.flags = SHF_ALLOC + SHF_EXECINSTR
if eh.machine == EM_X86_64 {
sh.entsize = 16
} else if eh.machine == EM_S390 {
sh.entsize = 32
} else if eh.machine == EM_PPC64 {
// On ppc64, this is just a table of addresses
// filled by the dynamic linker
sh.type_ = SHT_NOBITS
sh.flags = SHF_ALLOC + SHF_WRITE
sh.entsize = 8
} else {
sh.entsize = 4
}
sh.addralign = sh.entsize
shsym(sh, ctxt.Syms.Lookup(".plt", 0))
// On ppc64, .got comes from the input files, so don't
// create it here, and .got.plt is not used.
if eh.machine != EM_PPC64 {
sh := elfshname(".got")
sh.type_ = SHT_PROGBITS
sh.flags = SHF_ALLOC + SHF_WRITE
sh.entsize = uint64(SysArch.RegSize)
sh.addralign = uint64(SysArch.RegSize)
shsym(sh, ctxt.Syms.Lookup(".got", 0))
sh = elfshname(".got.plt")
sh.type_ = SHT_PROGBITS
sh.flags = SHF_ALLOC + SHF_WRITE
sh.entsize = uint64(SysArch.RegSize)
sh.addralign = uint64(SysArch.RegSize)
shsym(sh, ctxt.Syms.Lookup(".got.plt", 0))
}
sh = elfshname(".hash")
sh.type_ = SHT_HASH
sh.flags = SHF_ALLOC
sh.entsize = 4
sh.addralign = uint64(SysArch.RegSize)
sh.link = uint32(elfshname(".dynsym").shnum)
shsym(sh, ctxt.Syms.Lookup(".hash", 0))
/* sh and PT_DYNAMIC for .dynamic section */
sh = elfshname(".dynamic")
sh.type_ = SHT_DYNAMIC
sh.flags = SHF_ALLOC + SHF_WRITE
sh.entsize = 2 * uint64(SysArch.RegSize)
sh.addralign = uint64(SysArch.RegSize)
sh.link = uint32(elfshname(".dynstr").shnum)
shsym(sh, ctxt.Syms.Lookup(".dynamic", 0))
ph := newElfPhdr()
ph.type_ = PT_DYNAMIC
ph.flags = PF_R + PF_W
phsh(ph, sh)
/*
* Thread-local storage segment (really just size).
*/
tlssize := uint64(0)
for _, sect := range Segdata.Sections {
if sect.Name == ".tbss" {
tlssize = sect.Length
}
}
if tlssize != 0 {
ph := newElfPhdr()
ph.type_ = PT_TLS
ph.flags = PF_R
ph.memsz = tlssize
ph.align = uint64(SysArch.RegSize)
}
}
if Headtype == objabi.Hlinux {
ph := newElfPhdr()
ph.type_ = PT_GNU_STACK
ph.flags = PF_W + PF_R
ph.align = uint64(SysArch.RegSize)
ph = newElfPhdr()
ph.type_ = PT_PAX_FLAGS
ph.flags = 0x2a00 // mprotect, randexec, emutramp disabled
ph.align = uint64(SysArch.RegSize)
} else if Headtype == objabi.Hsolaris {
ph := newElfPhdr()
ph.type_ = PT_SUNWSTACK
ph.flags = PF_W + PF_R
}
elfobj:
sh := elfshname(".shstrtab")
sh.type_ = SHT_STRTAB
sh.addralign = 1
shsym(sh, ctxt.Syms.Lookup(".shstrtab", 0))
eh.shstrndx = uint16(sh.shnum)
// put these sections early in the list
if !*FlagS {
elfshname(".symtab")
elfshname(".strtab")
}
for _, sect := range Segtext.Sections {
elfshbits(sect)
}
for _, sect := range Segrodata.Sections {
elfshbits(sect)
}
for _, sect := range Segrelrodata.Sections {
elfshbits(sect)
}
for _, sect := range Segdata.Sections {
elfshbits(sect)
}
for _, sect := range Segdwarf.Sections {
elfshbits(sect)
}
if Linkmode == LinkExternal {
for _, sect := range Segtext.Sections {
elfshreloc(sect)
}
for _, sect := range Segrodata.Sections {
elfshreloc(sect)
}
for _, sect := range Segrelrodata.Sections {
elfshreloc(sect)
}
for _, sect := range Segdata.Sections {
elfshreloc(sect)
}
for _, s := range dwarfp {
if len(s.R) > 0 || s.Type == SDWARFINFO {
elfshreloc(s.Sect)
}
if s.Type == SDWARFINFO {
break
}
}
// add a .note.GNU-stack section to mark the stack as non-executable
sh := elfshname(".note.GNU-stack")
sh.type_ = SHT_PROGBITS
sh.addralign = 1
sh.flags = 0
}
if !*FlagS {
sh := elfshname(".symtab")
sh.type_ = SHT_SYMTAB
sh.off = uint64(symo)
sh.size = uint64(Symsize)
sh.addralign = uint64(SysArch.RegSize)
sh.entsize = 8 + 2*uint64(SysArch.RegSize)
sh.link = uint32(elfshname(".strtab").shnum)
sh.info = uint32(elfglobalsymndx)
sh = elfshname(".strtab")
sh.type_ = SHT_STRTAB
sh.off = uint64(symo) + uint64(Symsize)
sh.size = uint64(len(Elfstrdat))
sh.addralign = 1
}
/* Main header */
eh.ident[EI_MAG0] = '\177'
eh.ident[EI_MAG1] = 'E'
eh.ident[EI_MAG2] = 'L'
eh.ident[EI_MAG3] = 'F'
if Headtype == objabi.Hfreebsd {
eh.ident[EI_OSABI] = ELFOSABI_FREEBSD
} else if Headtype == objabi.Hnetbsd {
eh.ident[EI_OSABI] = ELFOSABI_NETBSD
} else if Headtype == objabi.Hopenbsd {
eh.ident[EI_OSABI] = ELFOSABI_OPENBSD
} else if Headtype == objabi.Hdragonfly {
eh.ident[EI_OSABI] = ELFOSABI_NONE
}
if elf64 {
eh.ident[EI_CLASS] = ELFCLASS64
} else {
eh.ident[EI_CLASS] = ELFCLASS32
}
if ctxt.Arch.ByteOrder == binary.BigEndian {
eh.ident[EI_DATA] = ELFDATA2MSB
} else {
eh.ident[EI_DATA] = ELFDATA2LSB
}
eh.ident[EI_VERSION] = EV_CURRENT
if Linkmode == LinkExternal {
eh.type_ = ET_REL
} else if Buildmode == BuildmodePIE {
eh.type_ = ET_DYN
} else {
eh.type_ = ET_EXEC
}
if Linkmode != LinkExternal {
eh.entry = uint64(Entryvalue(ctxt))
}
eh.version = EV_CURRENT
if pph != nil {
pph.filesz = uint64(eh.phnum) * uint64(eh.phentsize)
pph.memsz = pph.filesz
}
Cseek(0)
a := int64(0)
a += int64(elfwritehdr())
a += int64(elfwritephdrs())
a += int64(elfwriteshdrs())
if !*FlagD {
a += int64(elfwriteinterp())
}
if Linkmode != LinkExternal {
if Headtype == objabi.Hnetbsd {
a += int64(elfwritenetbsdsig())
}
if Headtype == objabi.Hopenbsd {
a += int64(elfwriteopenbsdsig())
}
if len(buildinfo) > 0 {
a += int64(elfwritebuildinfo())
}
if *flagBuildid != "" {
a += int64(elfwritegobuildid())
}
}
if a > elfreserve {
Errorf(nil, "ELFRESERVE too small: %d > %d with %d text sections", a, elfreserve, numtext)
}
}
func Elfadddynsym(ctxt *Link, s *Symbol) {
if elf64 {
s.Dynid = int32(Nelfsym)
Nelfsym++
d := ctxt.Syms.Lookup(".dynsym", 0)
name := s.Extname
Adduint32(ctxt, d, uint32(Addstring(ctxt.Syms.Lookup(".dynstr", 0), name)))
/* type */
t := STB_GLOBAL << 4
if s.Attr.CgoExport() && s.Type&SMASK == STEXT {
t |= STT_FUNC
} else {
t |= STT_OBJECT
}
Adduint8(ctxt, d, uint8(t))
/* reserved */
Adduint8(ctxt, d, 0)
/* section where symbol is defined */
if s.Type == SDYNIMPORT {
Adduint16(ctxt, d, SHN_UNDEF)
} else {
Adduint16(ctxt, d, 1)
}
/* value */
if s.Type == SDYNIMPORT {
Adduint64(ctxt, d, 0)
} else {
Addaddr(ctxt, d, s)
}
/* size of object */
Adduint64(ctxt, d, uint64(s.Size))
if SysArch.Family == sys.AMD64 && !s.Attr.CgoExportDynamic() && s.Dynimplib != "" && !seenlib[s.Dynimplib] {
Elfwritedynent(ctxt, ctxt.Syms.Lookup(".dynamic", 0), DT_NEEDED, uint64(Addstring(ctxt.Syms.Lookup(".dynstr", 0), s.Dynimplib)))
}
} else {
s.Dynid = int32(Nelfsym)
Nelfsym++
d := ctxt.Syms.Lookup(".dynsym", 0)
/* name */
name := s.Extname
Adduint32(ctxt, d, uint32(Addstring(ctxt.Syms.Lookup(".dynstr", 0), name)))
/* value */
if s.Type == SDYNIMPORT {
Adduint32(ctxt, d, 0)
} else {
Addaddr(ctxt, d, s)
}
/* size of object */
Adduint32(ctxt, d, uint32(s.Size))
/* type */
t := STB_GLOBAL << 4
// TODO(mwhudson): presumably the behavior should actually be the same on both arm and 386.
if SysArch.Family == sys.I386 && s.Attr.CgoExport() && s.Type&SMASK == STEXT {
t |= STT_FUNC
} else if SysArch.Family == sys.ARM && s.Attr.CgoExportDynamic() && s.Type&SMASK == STEXT {
t |= STT_FUNC
} else {
t |= STT_OBJECT
}
Adduint8(ctxt, d, uint8(t))
Adduint8(ctxt, d, 0)
/* shndx */
if s.Type == SDYNIMPORT {
Adduint16(ctxt, d, SHN_UNDEF)
} else {
Adduint16(ctxt, d, 1)
}
}
}
func ELF32_R_SYM(info uint32) uint32 {
return info >> 8
}
func ELF32_R_TYPE(info uint32) uint32 {
return uint32(uint8(info))
}
func ELF32_R_INFO(sym uint32, type_ uint32) uint32 {
return sym<<8 | type_
}
func ELF32_ST_BIND(info uint8) uint8 {
return info >> 4
}
func ELF32_ST_TYPE(info uint8) uint8 {
return info & 0xf
}
func ELF32_ST_INFO(bind uint8, type_ uint8) uint8 {
return bind<<4 | type_&0xf
}
func ELF32_ST_VISIBILITY(oth uint8) uint8 {
return oth & 3
}
func ELF64_R_SYM(info uint64) uint32 {
return uint32(info >> 32)
}
func ELF64_R_TYPE(info uint64) uint32 {
return uint32(info)
}
func ELF64_R_INFO(sym uint32, type_ uint32) uint64 {
return uint64(sym)<<32 | uint64(type_)
}
func ELF64_ST_BIND(info uint8) uint8 {
return info >> 4
}
func ELF64_ST_TYPE(info uint8) uint8 {
return info & 0xf
}
func ELF64_ST_INFO(bind uint8, type_ uint8) uint8 {
return bind<<4 | type_&0xf
}
func ELF64_ST_VISIBILITY(oth uint8) uint8 {
return oth & 3
}
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