Commit fd6cdbd8 authored by Russ Cox's avatar Russ Cox

linker work

  * more elf constants from FreeBSD
  * simple relocation demo

R=r
DELTA=410  (354 added, 49 deleted, 7 changed)
OCL=33689
CL=33729
parent c409976b
......@@ -148,7 +148,7 @@ addstring(Sym *s, char *str)
}
vlong
adduint32(Sym *s, uint32 v)
adduintxx(Sym *s, uint64 v, int wid)
{
vlong r;
Prog *p;
......@@ -157,28 +157,35 @@ adduint32(Sym *s, uint32 v)
s->type = SDATA;
s->reachable = 1;
r = s->value;
p = newdata(s, s->value, 4, D_EXTERN);
s->value += 4;
p = newdata(s, s->value, wid, D_EXTERN);
s->value += wid;
p->to.type = D_CONST;
p->to.offset = v;
return r;
}
vlong
adduint64(Sym *s, uint64 v)
adduint8(Sym *s, uint8 v)
{
vlong r;
Prog *p;
return adduintxx(s, v, 1);
}
if(s->type == 0)
s->type = SDATA;
s->reachable = 1;
r = s->value;
p = newdata(s, s->value, 8, D_EXTERN);
s->value += 8;
p->to.type = D_CONST;
p->to.offset = v;
return r;
vlong
adduint16(Sym *s, uint16 v)
{
return adduintxx(s, v, 2);
}
vlong
adduint32(Sym *s, uint32 v)
{
return adduintxx(s, v, 4);
}
vlong
adduint64(Sym *s, uint64 v)
{
return adduintxx(s, v, 8);
}
vlong
......@@ -230,8 +237,6 @@ datoff(vlong addr)
return 0;
}
int nrela;
enum {
ElfStrEmpty,
ElfStrInterp,
......@@ -274,6 +279,8 @@ doelf(void)
elfstr[ElfStrShstrtab] = addstring(shstrtab, ".shstrtab");
if(!debug['d']) { /* -d suppresses dynamic loader format */
Sym *dynamic, *dynstr;
elfstr[ElfStrInterp] = addstring(shstrtab, ".interp");
elfstr[ElfStrHash] = addstring(shstrtab, ".hash");
elfstr[ElfStrGot] = addstring(shstrtab, ".got");
......@@ -289,7 +296,12 @@ doelf(void)
s->type = SDATA; // TODO: rodata
addstring(lookup(".interp", 0), linuxdynld);
/* hash table - empty for now */
/*
* hash table - empty for now.
* we should have to fill it out with an entry for every
* symbol in .dynsym, but it seems to work not to,
* which is fine with me.
*/
s = lookup(".hash", 0);
s->type = SDATA; // TODO: rodata
s->reachable = 1;
......@@ -304,6 +316,7 @@ doelf(void)
/* dynamic string table */
s = lookup(".dynstr", 0);
addstring(s, "");
dynstr = s;
/* relocation table */
s = lookup(".rela", 0);
......@@ -322,6 +335,32 @@ doelf(void)
/* define dynamic elf table */
s = lookup(".dynamic", 0);
dynamic = s;
/*
* relocation demo - overwrite go func
* var main.extern_c_fib with fib symbol from fib.so
*/
Sym *fib;
fib = lookup("main·extern_c_fib", 0);
if(fib->type == SDATA || fib->type == SBSS) {
s = lookup(".rela", 0);
addaddr(s, fib);
adduint64(s, ELF64_R_INFO(1, R_X86_64_64)); // 1 = first symbol in dynsym
adduint64(s, 0);
s = lookup(".dynsym", 0);
adduint32(s, addstring(lookup(".dynstr", 0), "fib"));
adduint8(s, (STB_GLOBAL<<4) | STT_FUNC);
adduint8(s, 0); /* reserved */
adduint16(s, SHN_UNDEF); /* section where symbol is defined */
adduint64(s, 0); /* value */
adduint64(s, 0); /* size of object */
elfwritedynent(dynamic, DT_NEEDED, addstring(dynstr, "fib.so"));
}
s = dynamic;
elfwritedynentsym(s, DT_HASH, lookup(".hash", 0));
elfwritedynentsym(s, DT_SYMTAB, lookup(".dynsym", 0));
elfwritedynent(s, DT_SYMENT, ELF64SYMSIZE);
......@@ -332,32 +371,6 @@ doelf(void)
elfwritedynent(s, DT_RELAENT, ELF64RELASIZE);
elfwritedynent(s, DT_NULL, 0);
}
/*
putc = lookup("main·putc", 0);
if(putc->type != SDATA && putc->type != SBSS)
return;
// smash main.putc with putc
s = lookup(".elfrela", 0);
s->type = SDATA;
s->value = 24;
p = newdata(s, 0, 8, D_EXTERN); // r_offset
p->to.type = D_ADDR;
p->to.index = D_EXTERN;
p->to.sym = putc;
p = newdata(s, 8, 8, D_EXTERN); // r_info
p->to.type = D_CONST;
p->to.offset = ELF64_R_INFO(0, 1); // use 0 as symbol value; 1 is S+A calculation
p = newdata(s, 16, 8, D_EXTERN); // r_addend
p->to.type = D_CONST;
p->to.offset = 1000;
nrela = 1;
*/
}
void
......@@ -750,14 +763,6 @@ asmb(void)
/* Dynamic linking sections */
if (!debug['d']) { /* -d suppresses dynamic loader format */
/* S headers for dynamic linking */
sh = newElf64_Shdr(elfstr[ElfStrHash]);
sh->type = SHT_HASH;
sh->flags = SHF_ALLOC;
sh->entsize = 4;
sh->addralign = 8;
// sh->link = xxx;
shsym(sh, lookup(".hash", 0));
sh = newElf64_Shdr(elfstr[ElfStrGot]);
sh->type = SHT_PROGBITS;
sh->flags = SHF_ALLOC+SHF_WRITE;
......@@ -776,7 +781,7 @@ asmb(void)
sh = newElf64_Shdr(elfstr[ElfStrDynsym]);
sh->type = SHT_DYNSYM;
sh->flags = SHF_ALLOC;
sh->entsize = 1;
sh->entsize = ELF64SYMSIZE;
sh->addralign = 8;
sh->link = dynsym+1; // dynstr
// sh->info = index of first non-local symbol (number of local symbols)
......@@ -788,9 +793,18 @@ asmb(void)
sh->addralign = 1;
shsym(sh, lookup(".dynstr", 0));
sh = newElf64_Shdr(elfstr[ElfStrHash]);
sh->type = SHT_HASH;
sh->flags = SHF_ALLOC;
sh->entsize = 4;
sh->addralign = 8;
sh->link = dynsym;
shsym(sh, lookup(".hash", 0));
sh = newElf64_Shdr(elfstr[ElfStrRela]);
sh->type = SHT_RELA;
sh->flags = SHF_ALLOC;
sh->entsize = ELF64RELASIZE;
sh->addralign = 8;
sh->link = dynsym;
shsym(sh, lookup(".rela", 0));
......@@ -859,7 +873,6 @@ asmb(void)
sh->off = fo;
sh->size = w;
sh->addralign = 1;
sh->entsize = 24;
fo += w;
w = lcsize;
......@@ -869,7 +882,6 @@ asmb(void)
sh->off = fo;
sh->size = w;
sh->addralign = 1;
sh->entsize = 24;
}
sh = newElf64_Shstrtab(elfstr[ElfStrShstrtab]);
......
......@@ -3,8 +3,15 @@
* $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
......@@ -459,6 +466,292 @@ typedef struct {
/* Macro for constructing r_info from field values. */
#define ELF32_R_INFO(sym, type) (((sym) << 8) + (unsigned char)(type))
/*
* Relocation types.
*/
#define R_X86_64_NONE 0 /* No relocation. */
#define R_X86_64_64 1 /* Add 64 bit symbol value. */
#define R_X86_64_PC32 2 /* PC-relative 32 bit signed sym value. */
#define R_X86_64_GOT32 3 /* PC-relative 32 bit GOT offset. */
#define R_X86_64_PLT32 4 /* PC-relative 32 bit PLT offset. */
#define R_X86_64_COPY 5 /* Copy data from shared object. */
#define R_X86_64_GLOB_DAT 6 /* Set GOT entry to data address. */
#define R_X86_64_JMP_SLOT 7 /* Set GOT entry to code address. */
#define R_X86_64_RELATIVE 8 /* Add load address of shared object. */
#define R_X86_64_GOTPCREL 9 /* Add 32 bit signed pcrel offset to GOT. */
#define R_X86_64_32 10 /* Add 32 bit zero extended symbol value */
#define R_X86_64_32S 11 /* Add 32 bit sign extended symbol value */
#define R_X86_64_16 12 /* Add 16 bit zero extended symbol value */
#define R_X86_64_PC16 13 /* Add 16 bit signed extended pc relative symbol value */
#define R_X86_64_8 14 /* Add 8 bit zero extended symbol value */
#define R_X86_64_PC8 15 /* Add 8 bit signed extended pc relative symbol value */
#define R_X86_64_DTPMOD64 16 /* ID of module containing symbol */
#define R_X86_64_DTPOFF64 17 /* Offset in TLS block */
#define R_X86_64_TPOFF64 18 /* Offset in static TLS block */
#define R_X86_64_TLSGD 19 /* PC relative offset to GD GOT entry */
#define R_X86_64_TLSLD 20 /* PC relative offset to LD GOT entry */
#define R_X86_64_DTPOFF32 21 /* Offset in TLS block */
#define R_X86_64_GOTTPOFF 22 /* PC relative offset to IE GOT entry */
#define R_X86_64_TPOFF32 23 /* Offset in static TLS block */
#define R_X86_64_COUNT 24 /* Count of defined relocation types. */
#define R_ALPHA_NONE 0 /* No reloc */
#define R_ALPHA_REFLONG 1 /* Direct 32 bit */
#define R_ALPHA_REFQUAD 2 /* Direct 64 bit */
#define R_ALPHA_GPREL32 3 /* GP relative 32 bit */
#define R_ALPHA_LITERAL 4 /* GP relative 16 bit w/optimization */
#define R_ALPHA_LITUSE 5 /* Optimization hint for LITERAL */
#define R_ALPHA_GPDISP 6 /* Add displacement to GP */
#define R_ALPHA_BRADDR 7 /* PC+4 relative 23 bit shifted */
#define R_ALPHA_HINT 8 /* PC+4 relative 16 bit shifted */
#define R_ALPHA_SREL16 9 /* PC relative 16 bit */
#define R_ALPHA_SREL32 10 /* PC relative 32 bit */
#define R_ALPHA_SREL64 11 /* PC relative 64 bit */
#define R_ALPHA_OP_PUSH 12 /* OP stack push */
#define R_ALPHA_OP_STORE 13 /* OP stack pop and store */
#define R_ALPHA_OP_PSUB 14 /* OP stack subtract */
#define R_ALPHA_OP_PRSHIFT 15 /* OP stack right shift */
#define R_ALPHA_GPVALUE 16
#define R_ALPHA_GPRELHIGH 17
#define R_ALPHA_GPRELLOW 18
#define R_ALPHA_IMMED_GP_16 19
#define R_ALPHA_IMMED_GP_HI32 20
#define R_ALPHA_IMMED_SCN_HI32 21
#define R_ALPHA_IMMED_BR_HI32 22
#define R_ALPHA_IMMED_LO32 23
#define R_ALPHA_COPY 24 /* Copy symbol at runtime */
#define R_ALPHA_GLOB_DAT 25 /* Create GOT entry */
#define R_ALPHA_JMP_SLOT 26 /* Create PLT entry */
#define R_ALPHA_RELATIVE 27 /* Adjust by program base */
#define R_ALPHA_COUNT 28
#define R_ARM_NONE 0 /* No relocation. */
#define R_ARM_PC24 1
#define R_ARM_ABS32 2
#define R_ARM_REL32 3
#define R_ARM_PC13 4
#define R_ARM_ABS16 5
#define R_ARM_ABS12 6
#define R_ARM_THM_ABS5 7
#define R_ARM_ABS8 8
#define R_ARM_SBREL32 9
#define R_ARM_THM_PC22 10
#define R_ARM_THM_PC8 11
#define R_ARM_AMP_VCALL9 12
#define R_ARM_SWI24 13
#define R_ARM_THM_SWI8 14
#define R_ARM_XPC25 15
#define R_ARM_THM_XPC22 16
#define R_ARM_COPY 20 /* Copy data from shared object. */
#define R_ARM_GLOB_DAT 21 /* Set GOT entry to data address. */
#define R_ARM_JUMP_SLOT 22 /* Set GOT entry to code address. */
#define R_ARM_RELATIVE 23 /* Add load address of shared object. */
#define R_ARM_GOTOFF 24 /* Add GOT-relative symbol address. */
#define R_ARM_GOTPC 25 /* Add PC-relative GOT table address. */
#define R_ARM_GOT32 26 /* Add PC-relative GOT offset. */
#define R_ARM_PLT32 27 /* Add PC-relative PLT offset. */
#define R_ARM_GNU_VTENTRY 100
#define R_ARM_GNU_VTINHERIT 101
#define R_ARM_RSBREL32 250
#define R_ARM_THM_RPC22 251
#define R_ARM_RREL32 252
#define R_ARM_RABS32 253
#define R_ARM_RPC24 254
#define R_ARM_RBASE 255
#define R_ARM_COUNT 33 /* Count of defined relocation types. */
#define R_386_NONE 0 /* No relocation. */
#define R_386_32 1 /* Add symbol value. */
#define R_386_PC32 2 /* Add PC-relative symbol value. */
#define R_386_GOT32 3 /* Add PC-relative GOT offset. */
#define R_386_PLT32 4 /* Add PC-relative PLT offset. */
#define R_386_COPY 5 /* Copy data from shared object. */
#define R_386_GLOB_DAT 6 /* Set GOT entry to data address. */
#define R_386_JMP_SLOT 7 /* Set GOT entry to code address. */
#define R_386_RELATIVE 8 /* Add load address of shared object. */
#define R_386_GOTOFF 9 /* Add GOT-relative symbol address. */
#define R_386_GOTPC 10 /* Add PC-relative GOT table address. */
#define R_386_TLS_TPOFF 14 /* Negative offset in static TLS block */
#define R_386_TLS_IE 15 /* Absolute address of GOT for -ve static TLS */
#define R_386_TLS_GOTIE 16 /* GOT entry for negative static TLS block */
#define R_386_TLS_LE 17 /* Negative offset relative to static TLS */
#define R_386_TLS_GD 18 /* 32 bit offset to GOT (index,off) pair */
#define R_386_TLS_LDM 19 /* 32 bit offset to GOT (index,zero) pair */
#define R_386_TLS_GD_32 24 /* 32 bit offset to GOT (index,off) pair */
#define R_386_TLS_GD_PUSH 25 /* pushl instruction for Sun ABI GD sequence */
#define R_386_TLS_GD_CALL 26 /* call instruction for Sun ABI GD sequence */
#define R_386_TLS_GD_POP 27 /* popl instruction for Sun ABI GD sequence */
#define R_386_TLS_LDM_32 28 /* 32 bit offset to GOT (index,zero) pair */
#define R_386_TLS_LDM_PUSH 29 /* pushl instruction for Sun ABI LD sequence */
#define R_386_TLS_LDM_CALL 30 /* call instruction for Sun ABI LD sequence */
#define R_386_TLS_LDM_POP 31 /* popl instruction for Sun ABI LD sequence */
#define R_386_TLS_LDO_32 32 /* 32 bit offset from start of TLS block */
#define R_386_TLS_IE_32 33 /* 32 bit offset to GOT static TLS offset entry */
#define R_386_TLS_LE_32 34 /* 32 bit offset within static TLS block */
#define R_386_TLS_DTPMOD32 35 /* GOT entry containing TLS index */
#define R_386_TLS_DTPOFF32 36 /* GOT entry containing TLS offset */
#define R_386_TLS_TPOFF32 37 /* GOT entry of -ve static TLS offset */
#define R_386_COUNT 38 /* Count of defined relocation types. */
#define R_PPC_NONE 0 /* No relocation. */
#define R_PPC_ADDR32 1
#define R_PPC_ADDR24 2
#define R_PPC_ADDR16 3
#define R_PPC_ADDR16_LO 4
#define R_PPC_ADDR16_HI 5
#define R_PPC_ADDR16_HA 6
#define R_PPC_ADDR14 7
#define R_PPC_ADDR14_BRTAKEN 8
#define R_PPC_ADDR14_BRNTAKEN 9
#define R_PPC_REL24 10
#define R_PPC_REL14 11
#define R_PPC_REL14_BRTAKEN 12
#define R_PPC_REL14_BRNTAKEN 13
#define R_PPC_GOT16 14
#define R_PPC_GOT16_LO 15
#define R_PPC_GOT16_HI 16
#define R_PPC_GOT16_HA 17
#define R_PPC_PLTREL24 18
#define R_PPC_COPY 19
#define R_PPC_GLOB_DAT 20
#define R_PPC_JMP_SLOT 21
#define R_PPC_RELATIVE 22
#define R_PPC_LOCAL24PC 23
#define R_PPC_UADDR32 24
#define R_PPC_UADDR16 25
#define R_PPC_REL32 26
#define R_PPC_PLT32 27
#define R_PPC_PLTREL32 28
#define R_PPC_PLT16_LO 29
#define R_PPC_PLT16_HI 30
#define R_PPC_PLT16_HA 31
#define R_PPC_SDAREL16 32
#define R_PPC_SECTOFF 33
#define R_PPC_SECTOFF_LO 34
#define R_PPC_SECTOFF_HI 35
#define R_PPC_SECTOFF_HA 36
#define R_PPC_COUNT 37 /* Count of defined relocation types. */
#define R_PPC_TLS 67
#define R_PPC_DTPMOD32 68
#define R_PPC_TPREL16 69
#define R_PPC_TPREL16_LO 70
#define R_PPC_TPREL16_HI 71
#define R_PPC_TPREL16_HA 72
#define R_PPC_TPREL32 73
#define R_PPC_DTPREL16 74
#define R_PPC_DTPREL16_LO 75
#define R_PPC_DTPREL16_HI 76
#define R_PPC_DTPREL16_HA 77
#define R_PPC_DTPREL32 78
#define R_PPC_GOT_TLSGD16 79
#define R_PPC_GOT_TLSGD16_LO 80
#define R_PPC_GOT_TLSGD16_HI 81
#define R_PPC_GOT_TLSGD16_HA 82
#define R_PPC_GOT_TLSLD16 83
#define R_PPC_GOT_TLSLD16_LO 84
#define R_PPC_GOT_TLSLD16_HI 85
#define R_PPC_GOT_TLSLD16_HA 86
#define R_PPC_GOT_TPREL16 87
#define R_PPC_GOT_TPREL16_LO 88
#define R_PPC_GOT_TPREL16_HI 89
#define R_PPC_GOT_TPREL16_HA 90
#define R_PPC_EMB_NADDR32 101
#define R_PPC_EMB_NADDR16 102
#define R_PPC_EMB_NADDR16_LO 103
#define R_PPC_EMB_NADDR16_HI 104
#define R_PPC_EMB_NADDR16_HA 105
#define R_PPC_EMB_SDAI16 106
#define R_PPC_EMB_SDA2I16 107
#define R_PPC_EMB_SDA2REL 108
#define R_PPC_EMB_SDA21 109
#define R_PPC_EMB_MRKREF 110
#define R_PPC_EMB_RELSEC16 111
#define R_PPC_EMB_RELST_LO 112
#define R_PPC_EMB_RELST_HI 113
#define R_PPC_EMB_RELST_HA 114
#define R_PPC_EMB_BIT_FLD 115
#define R_PPC_EMB_RELSDA 116
/* Count of defined relocation types. */
#define R_PPC_EMB_COUNT (R_PPC_EMB_RELSDA - R_PPC_EMB_NADDR32 + 1)
#define R_SPARC_NONE 0
#define R_SPARC_8 1
#define R_SPARC_16 2
#define R_SPARC_32 3
#define R_SPARC_DISP8 4
#define R_SPARC_DISP16 5
#define R_SPARC_DISP32 6
#define R_SPARC_WDISP30 7
#define R_SPARC_WDISP22 8
#define R_SPARC_HI22 9
#define R_SPARC_22 10
#define R_SPARC_13 11
#define R_SPARC_LO10 12
#define R_SPARC_GOT10 13
#define R_SPARC_GOT13 14
#define R_SPARC_GOT22 15
#define R_SPARC_PC10 16
#define R_SPARC_PC22 17
#define R_SPARC_WPLT30 18
#define R_SPARC_COPY 19
#define R_SPARC_GLOB_DAT 20
#define R_SPARC_JMP_SLOT 21
#define R_SPARC_RELATIVE 22
#define R_SPARC_UA32 23
#define R_SPARC_PLT32 24
#define R_SPARC_HIPLT22 25
#define R_SPARC_LOPLT10 26
#define R_SPARC_PCPLT32 27
#define R_SPARC_PCPLT22 28
#define R_SPARC_PCPLT10 29
#define R_SPARC_10 30
#define R_SPARC_11 31
#define R_SPARC_64 32
#define R_SPARC_OLO10 33
#define R_SPARC_HH22 34
#define R_SPARC_HM10 35
#define R_SPARC_LM22 36
#define R_SPARC_PC_HH22 37
#define R_SPARC_PC_HM10 38
#define R_SPARC_PC_LM22 39
#define R_SPARC_WDISP16 40
#define R_SPARC_WDISP19 41
#define R_SPARC_GLOB_JMP 42
#define R_SPARC_7 43
#define R_SPARC_5 44
#define R_SPARC_6 45
#define R_SPARC_DISP64 46
#define R_SPARC_PLT64 47
#define R_SPARC_HIX22 48
#define R_SPARC_LOX10 49
#define R_SPARC_H44 50
#define R_SPARC_M44 51
#define R_SPARC_L44 52
#define R_SPARC_REGISTER 53
#define R_SPARC_UA64 54
#define R_SPARC_UA16 55
/*
* Magic number for the elf trampoline, chosen wisely to be an immediate
* value.
*/
#define ARM_MAGIC_TRAMP_NUMBER 0x5c000003
/*
* Symbol table entries.
*/
......@@ -599,7 +892,7 @@ typedef struct {
#define ELF64_R_TYPE(info) ((info) & 0xffffffffL)
/* Macro for constructing r_info from field values. */
#define ELF64_R_INFO(sym, type) (((sym) << 32) + ((type) & 0xffffffffL))
#define ELF64_R_INFO(sym, type) ((((uint64)(sym)) << 32) + (((uint64)(type)) & 0xffffffffULL))
/*
* Symbol table entries.
......
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