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go/src/cmd/6l/asm.c

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// Inferno utils/6l/asm.c
// http://code.google.com/p/inferno-os/source/browse/utils/6l/asm.c
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
// Writing object files.
#include "l.h"
#include "../ld/lib.h"
#include "../ld/elf.h"
#include "../ld/dwarf.h"
#include "../ld/macho.h"
#define Dbufslop 100
#define PADDR(a) ((uint32)(a) & ~0x80000000)
char linuxdynld[] = "/lib64/ld-linux-x86-64.so.2";
char freebsddynld[] = "/libexec/ld-elf.so.1";
char zeroes[32];
vlong
entryvalue(void)
{
char *a;
Sym *s;
a = INITENTRY;
if(*a >= '0' && *a <= '9')
return atolwhex(a);
s = lookup(a, 0);
if(s->type == 0)
return INITTEXT;
if(s->type != STEXT)
diag("entry not text: %s", s->name);
return s->value;
}
void
wputl(uint16 w)
{
cput(w);
cput(w>>8);
}
void
wputb(uint16 w)
{
cput(w>>8);
cput(w);
}
void
lputb(int32 l)
{
cput(l>>24);
cput(l>>16);
cput(l>>8);
cput(l);
}
void
vputb(uint64 v)
{
lputb(v>>32);
lputb(v);
}
void
lputl(int32 l)
{
cput(l);
cput(l>>8);
cput(l>>16);
cput(l>>24);
}
void
vputl(uint64 v)
{
lputl(v);
lputl(v>>32);
}
vlong
datoff(vlong addr)
{
if(addr >= segdata.vaddr)
return addr - segdata.vaddr + segdata.fileoff;
if(addr >= segtext.vaddr)
return addr - segtext.vaddr + segtext.fileoff;
diag("datoff %#llx", addr);
return 0;
}
enum {
ElfStrEmpty,
ElfStrInterp,
ElfStrHash,
ElfStrGot,
ElfStrGotPlt,
ElfStrDynamic,
ElfStrDynsym,
ElfStrDynstr,
ElfStrRela,
ElfStrText,
ElfStrData,
ElfStrBss,
ElfStrGosymcounts,
ElfStrGosymtab,
ElfStrGopclntab,
ElfStrShstrtab,
ElfStrSymtab,
ElfStrStrtab,
ElfStrRelaPlt,
ElfStrPlt,
NElfStr
};
vlong elfstr[NElfStr];
static int
needlib(char *name)
{
char *p;
Sym *s;
/* reuse hash code in symbol table */
p = smprint(".elfload.%s", name);
s = lookup(p, 0);
if(s->type == 0) {
s->type = 100; // avoid SDATA, etc.
return 1;
}
return 0;
}
int nelfsym = 1;
static void addpltsym(Sym*);
static void addgotsym(Sym*);
void
adddynrel(Sym *s, Reloc *r)
{
Sym *targ, *rela, *got;
targ = r->sym;
cursym = s;
switch(r->type) {
default:
if(r->type >= 256) {
diag("unexpected relocation type %d", r->type);
return;
}
break;
// Handle relocations found in ELF object files.
case 256 + R_X86_64_PC32:
if(targ->dynimpname)
diag("unexpected R_X86_64_PC32 relocation for dynamic symbol %s", targ->name);
if(targ->type == 0 || targ->type == SXREF)
diag("unknown symbol %s in pcrel", targ->name);
r->type = D_PCREL;
r->add += 4;
return;
case 256 + R_X86_64_PLT32:
addpltsym(targ);
r->type = D_PCREL;
r->sym = lookup(".plt", 0);
r->add += 4;
r->add += targ->plt;
return;
case 256 + R_X86_64_GOTPCREL:
addgotsym(targ);
r->type = D_PCREL;
r->sym = lookup(".got", 0);
r->add += 4;
r->add += targ->got;
return;
case 256 + R_X86_64_64:
if(targ->dynimpname)
diag("unexpected R_X86_64_64 relocation for dynamic symbol %s", targ->name);
r->type = D_ADDR;
return;
// Handle relocations found in Mach-O object files.
case 512 + MACHO_X86_64_RELOC_UNSIGNED*2 + 0:
case 512 + MACHO_X86_64_RELOC_SIGNED*2 + 0:
case 512 + MACHO_X86_64_RELOC_BRANCH*2 + 0:
// TODO: What is the difference between all these?
r->type = D_ADDR;
if(targ->dynimpname)
diag("unexpected reloc for dynamic symbol %s", targ->name);
return;
case 512 + MACHO_X86_64_RELOC_BRANCH*2 + 1:
if(targ->dynimpname) {
addpltsym(targ);
r->sym = lookup(".plt", 0);
r->add = targ->plt;
r->type = D_PCREL;
return;
}
// fall through
case 512 + MACHO_X86_64_RELOC_UNSIGNED*2 + 1:
case 512 + MACHO_X86_64_RELOC_SIGNED*2 + 1:
case 512 + MACHO_X86_64_RELOC_SIGNED_1*2 + 1:
case 512 + MACHO_X86_64_RELOC_SIGNED_2*2 + 1:
case 512 + MACHO_X86_64_RELOC_SIGNED_4*2 + 1:
r->type = D_PCREL;
if(targ->dynimpname)
diag("unexpected pc-relative reloc for dynamic symbol %s", targ->name);
return;
case 512 + MACHO_X86_64_RELOC_GOT_LOAD*2 + 1:
case 512 + MACHO_X86_64_RELOC_GOT*2 + 1:
// TODO: What is the difference between these two?
addgotsym(targ);
r->type = D_PCREL;
r->sym = lookup(".got", 0);
r->add += targ->got;
return;
}
// Handle references to ELF symbols from our own object files.
if(targ->dynimpname == nil)
return;
switch(r->type) {
case D_PCREL:
addpltsym(targ);
r->sym = lookup(".plt", 0);
r->add = targ->plt;
return;
case D_ADDR:
if(s->type != SDATA)
break;
if(iself) {
adddynsym(targ);
rela = lookup(".rela", 0);
addaddrplus(rela, s, r->off);
if(r->siz == 8)
adduint64(rela, ELF64_R_INFO(targ->dynid, R_X86_64_64));
else
adduint64(rela, ELF64_R_INFO(targ->dynid, R_X86_64_32));
adduint64(rela, r->add);
r->type = 256; // ignore during relocsym
return;
}
if(HEADTYPE == 6 && s->size == PtrSize && r->off == 0) {
// Mach-O relocations are a royal pain to lay out.
// They use a compact stateful bytecode representation
// that is too much bother to deal with.
// Instead, interpret the C declaration
// void *_Cvar_stderr = &stderr;
// as making _Cvar_stderr the name of a GOT entry
// for stderr. This is separate from the usual GOT entry,
// just in case the C code assigns to the variable,
// and of course it only works for single pointers,
// but we only need to support cgo and that's all it needs.
adddynsym(targ);
got = lookup(".got", 0);
s->type = got->type | SSUB;
s->outer = got;
s->sub = got->sub;
got->sub = s;
s->value = got->size;
adduint64(got, 0);
adduint32(lookup(".linkedit.got", 0), targ->dynid);
r->type = 256; // ignore during relocsym
return;
}
break;
}
cursym = s;
diag("unsupported relocation for dynamic symbol %s (type=%d stype=%d)", targ->name, r->type, targ->type);
}
int
archreloc(Reloc *r, Sym *s, vlong *val)
{
return -1;
}
static void
elfsetupplt(void)
{
Sym *plt, *got;
plt = lookup(".plt", 0);
got = lookup(".got.plt", 0);
if(plt->size == 0) {
// pushq got+8(IP)
adduint8(plt, 0xff);
adduint8(plt, 0x35);
addpcrelplus(plt, got, 8);
// jmpq got+16(IP)
adduint8(plt, 0xff);
adduint8(plt, 0x25);
addpcrelplus(plt, got, 16);
// nopl 0(AX)
adduint32(plt, 0x00401f0f);
// assume got->size == 0 too
addaddrplus(got, lookup(".dynamic", 0), 0);
adduint64(got, 0);
adduint64(got, 0);
}
}
static void
addpltsym(Sym *s)
{
if(s->plt >= 0)
return;
adddynsym(s);
if(iself) {
Sym *plt, *got, *rela;
plt = lookup(".plt", 0);
got = lookup(".got.plt", 0);
rela = lookup(".rela.plt", 0);
if(plt->size == 0)
elfsetupplt();
// jmpq *got+size(IP)
adduint8(plt, 0xff);
adduint8(plt, 0x25);
addpcrelplus(plt, got, got->size);
// add to got: pointer to current pos in plt
addaddrplus(got, plt, plt->size);
// pushq $x
adduint8(plt, 0x68);
adduint32(plt, (got->size-24-8)/8);
// jmpq .plt
adduint8(plt, 0xe9);
adduint32(plt, -(plt->size+4));
// rela
addaddrplus(rela, got, got->size-8);
adduint64(rela, ELF64_R_INFO(s->dynid, R_X86_64_JMP_SLOT));
adduint64(rela, 0);
s->plt = plt->size - 16;
} else if(HEADTYPE == 6) { // Mach-O
// To do lazy symbol lookup right, we're supposed
// to tell the dynamic loader which library each
// symbol comes from and format the link info
// section just so. I'm too lazy (ha!) to do that
// so for now we'll just use non-lazy pointers,
// which don't need to be told which library to use.
//
// http://networkpx.blogspot.com/2009/09/about-lcdyldinfoonly-command.html
// has details about what we're avoiding.
Sym *plt;
addgotsym(s);
plt = lookup(".plt", 0);
adduint32(lookup(".linkedit.plt", 0), s->dynid);
// jmpq *got+size(IP)
s->plt = plt->size;
adduint8(plt, 0xff);
adduint8(plt, 0x25);
addpcrelplus(plt, lookup(".got", 0), s->got);
} else {
diag("addpltsym: unsupported binary format");
}
}
static void
addgotsym(Sym *s)
{
Sym *got, *rela;
if(s->got >= 0)
return;
adddynsym(s);
got = lookup(".got", 0);
s->got = got->size;
adduint64(got, 0);
if(iself) {
rela = lookup(".rela", 0);
addaddrplus(rela, got, s->got);
adduint64(rela, ELF64_R_INFO(s->dynid, R_X86_64_GLOB_DAT));
adduint64(rela, 0);
} else if(HEADTYPE == 6) { // Mach-O
adduint32(lookup(".linkedit.got", 0), s->dynid);
} else {
diag("addgotsym: unsupported binary format");
}
}
void
adddynsym(Sym *s)
{
Sym *d, *str;
int t;
char *name;
if(s->dynid >= 0)
return;
if(iself) {
s->dynid = nelfsym++;
d = lookup(".dynsym", 0);
name = s->dynimpname;
if(name == nil)
name = s->name;
adduint32(d, addstring(lookup(".dynstr", 0), name));
/* type */
t = STB_GLOBAL << 4;
if(s->dynexport && s->type == STEXT)
t |= STT_FUNC;
else
t |= STT_OBJECT;
adduint8(d, t);
/* reserved */
adduint8(d, 0);
/* section where symbol is defined */
if(!s->dynexport && s->dynimpname != nil)
adduint16(d, SHN_UNDEF);
else {
switch(s->type) {
default:
case STEXT:
t = 11;
break;
case SRODATA:
t = 12;
break;
case SDATA:
t = 13;
break;
case SBSS:
t = 14;
break;
}
adduint16(d, t);
}
/* value */
if(s->type == SDYNIMPORT)
adduint64(d, 0);
else
addaddr(d, s);
/* size of object */
adduint64(d, 0);
if(!s->dynexport && s->dynimplib && needlib(s->dynimplib)) {
elfwritedynent(lookup(".dynamic", 0), DT_NEEDED,
addstring(lookup(".dynstr", 0), s->dynimplib));
}
} else if(HEADTYPE == 6) {
// Mach-o symbol nlist64
d = lookup(".dynsym", 0);
name = s->dynimpname;
if(name == nil)
name = s->name;
s->dynid = d->size/16;
// darwin still puts _ prefixes on all C symbols
str = lookup(".dynstr", 0);
adduint32(d, str->size);
adduint8(str, '_');
addstring(str, name);
adduint8(d, 0x01); // type - N_EXT - external symbol
adduint8(d, 0); // section
adduint16(d, 0); // desc
adduint64(d, 0); // value
} else {
diag("adddynsym: unsupported binary format");
}
}
void
adddynlib(char *lib)
{
Sym *s;
if(!needlib(lib))
return;
if(iself) {
s = lookup(".dynstr", 0);
if(s->size == 0)
addstring(s, "");
elfwritedynent(lookup(".dynamic", 0), DT_NEEDED, addstring(s, lib));
} else if(HEADTYPE == 6) { // Mach-O
machoadddynlib(lib);
} else {
diag("adddynlib: unsupported binary format");
}
}
void
doelf(void)
{
Sym *s, *shstrtab, *dynstr;
if(HEADTYPE != 7 && HEADTYPE != 9)
return;
/* predefine strings we need for section headers */
shstrtab = lookup(".shstrtab", 0);
shstrtab->type = SELFDATA;
shstrtab->reachable = 1;
elfstr[ElfStrEmpty] = addstring(shstrtab, "");
elfstr[ElfStrText] = addstring(shstrtab, ".text");
elfstr[ElfStrData] = addstring(shstrtab, ".data");
elfstr[ElfStrBss] = addstring(shstrtab, ".bss");
addstring(shstrtab, ".elfdata");
addstring(shstrtab, ".rodata");
if(!debug['s']) {
elfstr[ElfStrGosymcounts] = addstring(shstrtab, ".gosymcounts");
elfstr[ElfStrGosymtab] = addstring(shstrtab, ".gosymtab");
elfstr[ElfStrGopclntab] = addstring(shstrtab, ".gopclntab");
elfstr[ElfStrSymtab] = addstring(shstrtab, ".symtab");
elfstr[ElfStrStrtab] = addstring(shstrtab, ".strtab");
dwarfaddshstrings(shstrtab);
}
elfstr[ElfStrShstrtab] = addstring(shstrtab, ".shstrtab");
if(!debug['d']) { /* -d suppresses dynamic loader format */
elfstr[ElfStrInterp] = addstring(shstrtab, ".interp");
elfstr[ElfStrHash] = addstring(shstrtab, ".hash");
elfstr[ElfStrGot] = addstring(shstrtab, ".got");
elfstr[ElfStrGotPlt] = addstring(shstrtab, ".got.plt");
elfstr[ElfStrDynamic] = addstring(shstrtab, ".dynamic");
elfstr[ElfStrDynsym] = addstring(shstrtab, ".dynsym");
elfstr[ElfStrDynstr] = addstring(shstrtab, ".dynstr");
elfstr[ElfStrRela] = addstring(shstrtab, ".rela");
elfstr[ElfStrRelaPlt] = addstring(shstrtab, ".rela.plt");
elfstr[ElfStrPlt] = addstring(shstrtab, ".plt");
/* dynamic symbol table - first entry all zeros */
s = lookup(".dynsym", 0);
s->type = SELFDATA;
s->reachable = 1;
s->size += ELF64SYMSIZE;
/* dynamic string table */
s = lookup(".dynstr", 0);
s->type = SELFDATA;
s->reachable = 1;
if(s->size == 0)
addstring(s, "");
dynstr = s;
/* relocation table */
s = lookup(".rela", 0);
s->reachable = 1;
s->type = SELFDATA;
/* global offset table */
s = lookup(".got", 0);
s->reachable = 1;
s->type = SDATA; // writable, so not SELFDATA
/* hash */
s = lookup(".hash", 0);
s->reachable = 1;
s->type = SELFDATA;
s = lookup(".got.plt", 0);
s->reachable = 1;
s->type = SDATA; // writable, not SELFDATA
s = lookup(".plt", 0);
s->reachable = 1;
s->type = SELFDATA;
elfsetupplt();
s = lookup(".rela.plt", 0);
s->reachable = 1;
s->type = SELFDATA;
/* define dynamic elf table */
s = lookup(".dynamic", 0);
s->reachable = 1;
s->type = SELFDATA;
/*
* .dynamic table
*/
elfwritedynentsym(s, DT_HASH, lookup(".hash", 0));
elfwritedynentsym(s, DT_SYMTAB, lookup(".dynsym", 0));
elfwritedynent(s, DT_SYMENT, ELF64SYMSIZE);
elfwritedynentsym(s, DT_STRTAB, lookup(".dynstr", 0));
elfwritedynentsymsize(s, DT_STRSZ, lookup(".dynstr", 0));
elfwritedynentsym(s, DT_RELA, lookup(".rela", 0));
elfwritedynentsymsize(s, DT_RELASZ, lookup(".rela", 0));
elfwritedynent(s, DT_RELAENT, ELF64RELASIZE);
if(rpath)
elfwritedynent(s, DT_RUNPATH, addstring(dynstr, rpath));
elfwritedynentsym(s, DT_PLTGOT, lookup(".got.plt", 0));
elfwritedynent(s, DT_PLTREL, DT_RELA);
elfwritedynentsymsize(s, DT_PLTRELSZ, lookup(".rela.plt", 0));
elfwritedynentsym(s, DT_JMPREL, lookup(".rela.plt", 0));
elfwritedynent(s, DT_NULL, 0);
}
}
void
shsym(ElfShdr *sh, Sym *s)
{
sh->addr = symaddr(s);
sh->off = datoff(sh->addr);
sh->size = s->size;
}
void
phsh(ElfPhdr *ph, ElfShdr *sh)
{
ph->vaddr = sh->addr;
ph->paddr = ph->vaddr;
ph->off = sh->off;
ph->filesz = sh->size;
ph->memsz = sh->size;
ph->align = sh->addralign;
}
void
asmb(void)
{
int32 magic;
int a, dynsym;
vlong vl, va, startva, fo, w, symo, elfsymo, elfstro, elfsymsize, machlink;
ElfEhdr *eh;
ElfPhdr *ph, *pph;
ElfShdr *sh;
Section *sect;
if(debug['v'])
Bprint(&bso, "%5.2f asmb\n", cputime());
Bflush(&bso);
elftextsh = 0;
elfsymsize = 0;
elfstro = 0;
elfsymo = 0;
if(debug['v'])
Bprint(&bso, "%5.2f codeblk\n", cputime());
Bflush(&bso);
sect = segtext.sect;
seek(cout, sect->vaddr - segtext.vaddr + segtext.fileoff, 0);
codeblk(sect->vaddr, sect->len);
/* output read-only data in text segment */
sect = segtext.sect->next;
seek(cout, sect->vaddr - segtext.vaddr + segtext.fileoff, 0);
datblk(sect->vaddr, sect->len);
if(debug['v'])
Bprint(&bso, "%5.2f datblk\n", cputime());
Bflush(&bso);
seek(cout, segdata.fileoff, 0);
datblk(segdata.vaddr, segdata.filelen);
machlink = 0;
if(HEADTYPE == 6)
machlink = domacholink();
switch(HEADTYPE) {
default:
diag("unknown header type %d", HEADTYPE);
case 2:
case 5:
break;
case 6:
debug['8'] = 1; /* 64-bit addresses */
break;
case 7:
case 9:
debug['8'] = 1; /* 64-bit addresses */
/* index of elf text section; needed by asmelfsym, double-checked below */
/* !debug['d'] causes extra sections before the .text section */
elftextsh = 1;
if(!debug['d'])
elftextsh += 10;
break;
}
symsize = 0;
spsize = 0;
lcsize = 0;
symo = 0;
if(!debug['s']) {
if(debug['v'])
Bprint(&bso, "%5.2f sym\n", cputime());
Bflush(&bso);
switch(HEADTYPE) {
default:
case 2:
case 5:
debug['s'] = 1;
symo = HEADR+segtext.len+segdata.filelen;
break;
case 6:
symo = rnd(HEADR+segtext.len, INITRND)+rnd(segdata.filelen, INITRND)+machlink;
break;
case 7:
case 9:
symo = rnd(HEADR+segtext.len, INITRND)+segdata.filelen;
symo = rnd(symo, INITRND);
break;
}
/*
* the symbol information is stored as
* 32-bit symbol table size
* 32-bit line number table size
* symbol table
* line number table
*/
seek(cout, symo+8, 0);
if(debug['v'])
Bprint(&bso, "%5.2f sp\n", cputime());
Bflush(&bso);
if(debug['v'])
Bprint(&bso, "%5.2f pc\n", cputime());
Bflush(&bso);
if(!debug['s'])
strnput("", INITRND-(8+symsize+lcsize)%INITRND);
cflush();
seek(cout, symo, 0);
lputl(symsize);
lputl(lcsize);
cflush();
if(!debug['s']) {
elfsymo = symo+8+symsize+lcsize;
seek(cout, elfsymo, 0);
asmelfsym64();
cflush();
elfstro = seek(cout, 0, 1);
elfsymsize = elfstro - elfsymo;
ewrite(cout, elfstrdat, elfstrsize);
if(debug['v'])
Bprint(&bso, "%5.2f dwarf\n", cputime());
dwarfemitdebugsections();
}
}
if(debug['v'])
Bprint(&bso, "%5.2f headr\n", cputime());
Bflush(&bso);
seek(cout, 0L, 0);
switch(HEADTYPE) {
default:
case 2: /* plan9 */
magic = 4*26*26+7;
magic |= 0x00008000; /* fat header */
lputb(magic); /* magic */
lputb(segtext.filelen); /* sizes */
lputb(segdata.filelen);
lputb(segdata.len - segdata.filelen);
lputb(symsize); /* nsyms */
vl = entryvalue();
lputb(PADDR(vl)); /* va of entry */
lputb(spsize); /* sp offsets */
lputb(lcsize); /* line offsets */
vputb(vl); /* va of entry */
break;
case 3: /* plan9 */
magic = 4*26*26+7;
lputb(magic); /* magic */
lputb(segtext.filelen); /* sizes */
lputb(segdata.filelen);
lputb(segdata.len - segdata.filelen);
lputb(symsize); /* nsyms */
lputb(entryvalue()); /* va of entry */
lputb(spsize); /* sp offsets */
lputb(lcsize); /* line offsets */
break;
case 6:
asmbmacho();
break;
case 7:
case 9:
/* elf amd-64 */
eh = getElfEhdr();
fo = HEADR;
startva = INITTEXT - HEADR;
va = startva + fo;
w = segtext.filelen;
/* This null SHdr must appear before all others */
sh = newElfShdr(elfstr[ElfStrEmpty]);
/* program header info */
pph = newElfPhdr();
pph->type = PT_PHDR;
pph->flags = PF_R + PF_X;
pph->off = eh->ehsize;
pph->vaddr = INITTEXT - HEADR + pph->off;
pph->paddr = INITTEXT - HEADR + pph->off;
pph->align = INITRND;
if(!debug['d']) {
/* interpreter */
sh = newElfShdr(elfstr[ElfStrInterp]);
sh->type = SHT_PROGBITS;
sh->flags = SHF_ALLOC;
sh->addralign = 1;
switch(HEADTYPE) {
case 7:
elfinterp(sh, startva, linuxdynld);
break;
case 9:
elfinterp(sh, startva, freebsddynld);
break;
}
ph = newElfPhdr();
ph->type = PT_INTERP;
ph->flags = PF_R;
phsh(ph, sh);
}
elfphload(&segtext);
elfphload(&segdata);
/* Dynamic linking sections */
if (!debug['d']) { /* -d suppresses dynamic loader format */
/* S headers for dynamic linking */
sh = newElfShdr(elfstr[ElfStrGot]);
sh->type = SHT_PROGBITS;
sh->flags = SHF_ALLOC+SHF_WRITE;
sh->entsize = 8;
sh->addralign = 8;
shsym(sh, lookup(".got", 0));
sh = newElfShdr(elfstr[ElfStrGotPlt]);
sh->type = SHT_PROGBITS;
sh->flags = SHF_ALLOC+SHF_WRITE;
sh->entsize = 8;
sh->addralign = 8;
shsym(sh, lookup(".got.plt", 0));
dynsym = eh->shnum;
sh = newElfShdr(elfstr[ElfStrDynsym]);
sh->type = SHT_DYNSYM;
sh->flags = SHF_ALLOC;
sh->entsize = ELF64SYMSIZE;
sh->addralign = 8;
sh->link = dynsym+1; // dynstr
// sh->info = index of first non-local symbol (number of local symbols)
shsym(sh, lookup(".dynsym", 0));
sh = newElfShdr(elfstr[ElfStrDynstr]);
sh->type = SHT_STRTAB;
sh->flags = SHF_ALLOC;
sh->addralign = 1;
shsym(sh, lookup(".dynstr", 0));
sh = newElfShdr(elfstr[ElfStrRelaPlt]);
sh->type = SHT_RELA;
sh->flags = SHF_ALLOC;
sh->entsize = ELF64RELASIZE;
sh->addralign = 8;
sh->link = dynsym;
sh->info = eh->shnum; // .plt
shsym(sh, lookup(".rela.plt", 0));
sh = newElfShdr(elfstr[ElfStrPlt]);
sh->type = SHT_PROGBITS;
sh->flags = SHF_ALLOC+SHF_EXECINSTR;
sh->entsize = 16;
sh->addralign = 4;
shsym(sh, lookup(".plt", 0));
sh = newElfShdr(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 = newElfShdr(elfstr[ElfStrRela]);
sh->type = SHT_RELA;
sh->flags = SHF_ALLOC;
sh->entsize = ELF64RELASIZE;
sh->addralign = 8;
sh->link = dynsym;
shsym(sh, lookup(".rela", 0));
/* sh and PT_DYNAMIC for .dynamic section */
sh = newElfShdr(elfstr[ElfStrDynamic]);
sh->type = SHT_DYNAMIC;
sh->flags = SHF_ALLOC+SHF_WRITE;
sh->entsize = 16;
sh->addralign = 8;
sh->link = dynsym+1; // dynstr
shsym(sh, 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).
*/
if(tlsoffset != 0) {
ph = newElfPhdr();
ph->type = PT_TLS;
ph->flags = PF_R;
ph->memsz = -tlsoffset;
ph->align = 8;
}
}
ph = newElfPhdr();
ph->type = PT_GNU_STACK;
ph->flags = PF_W+PF_R;
ph->align = 8;
if(elftextsh != eh->shnum)
diag("elftextsh = %d, want %d", elftextsh, eh->shnum);
for(sect=segtext.sect; sect!=nil; sect=sect->next)
elfshbits(sect);
for(sect=segdata.sect; sect!=nil; sect=sect->next)
elfshbits(sect);
if (!debug['s']) {
sh = newElfShdr(elfstr[ElfStrGosymtab]);
sh->type = SHT_PROGBITS;
sh->flags = SHF_ALLOC;
sh->addralign = 1;
shsym(sh, lookup("symtab", 0));
sh = newElfShdr(elfstr[ElfStrGopclntab]);
sh->type = SHT_PROGBITS;
sh->flags = SHF_ALLOC;
sh->addralign = 1;
shsym(sh, lookup("pclntab", 0));
sh = newElfShdr(elfstr[ElfStrSymtab]);
sh->type = SHT_SYMTAB;
sh->off = elfsymo;
sh->size = elfsymsize;
sh->addralign = 8;
sh->entsize = 24;
sh->link = eh->shnum; // link to strtab
sh = newElfShdr(elfstr[ElfStrStrtab]);
sh->type = SHT_STRTAB;
sh->off = elfstro;
sh->size = elfstrsize;
sh->addralign = 1;
dwarfaddelfheaders();
}
sh = newElfShstrtab(elfstr[ElfStrShstrtab]);
sh->type = SHT_STRTAB;
sh->addralign = 1;
shsym(sh, lookup(".shstrtab", 0));
/* Main header */
eh->ident[EI_MAG0] = '\177';
eh->ident[EI_MAG1] = 'E';
eh->ident[EI_MAG2] = 'L';
eh->ident[EI_MAG3] = 'F';
if(HEADTYPE == 9)
eh->ident[EI_OSABI] = 9;
eh->ident[EI_CLASS] = ELFCLASS64;
eh->ident[EI_DATA] = ELFDATA2LSB;
eh->ident[EI_VERSION] = EV_CURRENT;
eh->type = ET_EXEC;
eh->machine = EM_X86_64;
eh->version = EV_CURRENT;
eh->entry = entryvalue();
pph->filesz = eh->phnum * eh->phentsize;
pph->memsz = pph->filesz;
seek(cout, 0, 0);
a = 0;
a += elfwritehdr();
a += elfwritephdrs();
a += elfwriteshdrs();
cflush();
if(a+elfwriteinterp() > ELFRESERVE)
diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
break;
}
cflush();
}
void
cflush(void)
{
int n;
n = sizeof(buf.cbuf) - cbc;
if(n)
ewrite(cout, buf.cbuf, n);
cbp = buf.cbuf;
cbc = sizeof(buf.cbuf);
}
/* Current position in file */
vlong
cpos(void)
{
return seek(cout, 0, 1) + sizeof(buf.cbuf) - cbc;
}
vlong
rnd(vlong v, vlong r)
{
vlong c;
if(r <= 0)
return v;
v += r - 1;
c = v % r;
if(c < 0)
c += r;
v -= c;
return v;
}
void
genasmsym(void (*put)(Sym*, char*, int, vlong, vlong, int, Sym*))
{
Auto *a;
Sym *s;
int h;
for(h=0; h<NHASH; h++) {
for(s=hash[h]; s!=S; s=s->hash) {
switch(s->type&~SSUB) {
case SCONST:
case SRODATA:
case SDATA:
case SELFDATA:
case SMACHOGOT:
if(!s->reachable)
continue;
put(s, s->name, 'D', symaddr(s), s->size, s->version, s->gotype);
continue;
case SBSS:
if(!s->reachable)
continue;
put(s, s->name, 'B', symaddr(s), s->size, s->version, s->gotype);
continue;
case SFILE:
put(nil, s->name, 'f', s->value, 0, s->version, 0);
continue;
}
}
}
for(s = textp; s != nil; s = s->next) {
if(s->text == nil)
continue;
/* filenames first */
for(a=s->autom; a; a=a->link)
if(a->type == D_FILE)
put(nil, a->asym->name, 'z', a->aoffset, 0, 0, 0);
else
if(a->type == D_FILE1)
put(nil, a->asym->name, 'Z', a->aoffset, 0, 0, 0);
put(s, s->name, 'T', s->value, s->size, s->version, s->gotype);
/* frame, auto and param after */
put(nil, ".frame", 'm', s->text->to.offset+8, 0, 0, 0);
for(a=s->autom; a; a=a->link)
if(a->type == D_AUTO)
put(nil, a->asym->name, 'a', -a->aoffset, 0, 0, a->gotype);
else
if(a->type == D_PARAM)
put(nil, a->asym->name, 'p', a->aoffset, 0, 0, a->gotype);
}
if(debug['v'] || debug['n'])
Bprint(&bso, "symsize = %ud\n", symsize);
Bflush(&bso);
}
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