qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-10-04 07:21:22 -06:00
Code Releases Activity
10b53867e8
go/src/libmach/executable.c
Russ Cox 19fd5c787f 5l, 6l, 8l: link pclntab and symtab as ordinary rodata symbols 
That is, move the pc/ln table and the symbol table
into the read-only data segment.  This eliminates
the need for a special load command to map the
symbol table into memory, which makes the
information available on systems that couldn't handle
the magic load to 0x99000000, like NaCl and ARM QEMU
and Linux without config_highmem=y.  It also
eliminates an #ifdef and some clumsy code to
find the symbol table on Windows.

The bad news is that the binary appears to be bigger
than it used to be.  This is not actually the case, though:
the same amount of data is being mapped into memory
as before, and the tables are still read-only, so they're
still shared across multiple instances of the binary as
they were before.  The difference is just that the tables
aren't squirreled away in some section that "size" doesn't
know to look at.

This is a checkpoint.
It probably breaks Windows and breaks NaCl more
than it used to be broken, but those will be fixed.
The logic involving -s needs to be revisited too.

Fixes #871.

R=ken2
CC=golang-dev
https://golang.org/cl/2587041
2010-10-19 18:07:19 -04:00

1283 lines
29 KiB
C
Raw Blame History

// Inferno libmach/executable.c
// http://code.google.com/p/inferno-os/source/browse/utils/libmach/executable.c
//
// Copyright © 1994-1999 Lucent Technologies Inc.
// Power PC support Copyright © 1995-2004 C H Forsyth (forsyth@terzarima.net).
// Portions Copyright © 1997-1999 Vita Nuova Limited.
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com).
// Revisions Copyright © 2000-2004 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.
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <bootexec.h>
#include <mach.h>
#include "elf.h"
#include "macho.h"
/*
* All a.out header types. The dummy entry allows canonical
* processing of the union as a sequence of int32s
*/
typedef struct {
union{
/*struct { */
Exec exechdr; /* a.out.h */
/* uvlong hdr[1];*/
/*};*/
Ehdr32 elfhdr32; /* elf.h */
Ehdr64 elfhdr64; /* elf.h */
struct mipsexec mips; /* bootexec.h */
struct mips4kexec mipsk4; /* bootexec.h */
struct sparcexec sparc; /* bootexec.h */
struct nextexec next; /* bootexec.h */
Machhdr machhdr; /* macho.h */
} e;
int32 dummy; /* padding to ensure extra int32 */
} ExecHdr;
static int nextboot(int, Fhdr*, ExecHdr*);
static int sparcboot(int, Fhdr*, ExecHdr*);
static int mipsboot(int, Fhdr*, ExecHdr*);
static int mips4kboot(int, Fhdr*, ExecHdr*);
static int common(int, Fhdr*, ExecHdr*);
static int commonllp64(int, Fhdr*, ExecHdr*);
static int adotout(int, Fhdr*, ExecHdr*);
static int elfdotout(int, Fhdr*, ExecHdr*);
static int machdotout(int, Fhdr*, ExecHdr*);
static int armdotout(int, Fhdr*, ExecHdr*);
static void setsym(Fhdr*, vlong, int32, vlong, int32, vlong, int32);
static void setdata(Fhdr*, uvlong, int32, vlong, int32);
static void settext(Fhdr*, uvlong, uvlong, int32, vlong);
static void hswal(void*, int, uint32(*)(uint32));
static uvlong _round(uvlong, uint32);
/*
* definition of per-executable file type structures
*/
typedef struct Exectable{
int32 magic; /* big-endian magic number of file */
char *name; /* executable identifier */
char *dlmname; /* dynamically loadable module identifier */
uchar type; /* Internal code */
uchar _magic; /* _MAGIC() magic */
Mach *mach; /* Per-machine data */
int32 hsize; /* header size */
uint32 (*swal)(uint32); /* beswal or leswal */
int (*hparse)(int, Fhdr*, ExecHdr*);
} ExecTable;
extern Mach mmips;
extern Mach mmips2le;
extern Mach mmips2be;
extern Mach msparc;
extern Mach msparc64;
extern Mach m68020;
extern Mach mi386;
extern Mach mamd64;
extern Mach marm;
extern Mach mpower;
extern Mach mpower64;
extern Mach malpha;
/* BUG: FIX THESE WHEN NEEDED */
Mach mmips;
Mach mmips2le;
Mach mmips2be;
Mach msparc;
Mach msparc64;
Mach m68020;
Mach mpower;
Mach mpower64;
Mach malpha;
ExecTable exectab[] =
{
{ V_MAGIC, /* Mips v.out */
"mips plan 9 executable BE",
"mips plan 9 dlm BE",
FMIPS,
1,
&mmips,
sizeof(Exec),
beswal,
adotout },
{ P_MAGIC, /* Mips 0.out (r3k le) */
"mips plan 9 executable LE",
"mips plan 9 dlm LE",
FMIPSLE,
1,
&mmips,
sizeof(Exec),
beswal,
adotout },
{ M_MAGIC, /* Mips 4.out */
"mips 4k plan 9 executable BE",
"mips 4k plan 9 dlm BE",
FMIPS2BE,
1,
&mmips2be,
sizeof(Exec),
beswal,
adotout },
{ N_MAGIC, /* Mips 0.out */
"mips 4k plan 9 executable LE",
"mips 4k plan 9 dlm LE",
FMIPS2LE,
1,
&mmips2le,
sizeof(Exec),
beswal,
adotout },
{ 0x160<<16, /* Mips boot image */
"mips plan 9 boot image",
nil,
FMIPSB,
0,
&mmips,
sizeof(struct mipsexec),
beswal,
mipsboot },
{ (0x160<<16)|3, /* Mips boot image */
"mips 4k plan 9 boot image",
nil,
FMIPSB,
0,
&mmips2be,
sizeof(struct mips4kexec),
beswal,
mips4kboot },
{ K_MAGIC, /* Sparc k.out */
"sparc plan 9 executable",
"sparc plan 9 dlm",
FSPARC,
1,
&msparc,
sizeof(Exec),
beswal,
adotout },
{ 0x01030107, /* Sparc boot image */
"sparc plan 9 boot image",
nil,
FSPARCB,
0,
&msparc,
sizeof(struct sparcexec),
beswal,
sparcboot },
{ U_MAGIC, /* Sparc64 u.out */
"sparc64 plan 9 executable",
"sparc64 plan 9 dlm",
FSPARC64,
1,
&msparc64,
sizeof(Exec),
beswal,
adotout },
{ A_MAGIC, /* 68020 2.out & boot image */
"68020 plan 9 executable",
"68020 plan 9 dlm",
F68020,
1,
&m68020,
sizeof(Exec),
beswal,
common },
{ 0xFEEDFACE, /* Next boot image */
"next plan 9 boot image",
nil,
FNEXTB,
0,
&m68020,
sizeof(struct nextexec),
beswal,
nextboot },
{ I_MAGIC, /* I386 8.out & boot image */
"386 plan 9 executable",
"386 plan 9 dlm",
FI386,
1,
&mi386,
sizeof(Exec),
beswal,
common },
{ S_MAGIC, /* amd64 6.out & boot image */
"amd64 plan 9 executable",
"amd64 plan 9 dlm",
FAMD64,
1,
&mamd64,
sizeof(Exec)+8,
nil,
commonllp64 },
{ Q_MAGIC, /* PowerPC q.out & boot image */
"power plan 9 executable",
"power plan 9 dlm",
FPOWER,
1,
&mpower,
sizeof(Exec),
beswal,
common },
{ T_MAGIC, /* power64 9.out & boot image */
"power64 plan 9 executable",
"power64 plan 9 dlm",
FPOWER64,
1,
&mpower64,
sizeof(Exec)+8,
nil,
commonllp64 },
{ ELF_MAG, /* any elf32 or elf64 */
"elf executable",
nil,
FNONE,
0,
&mi386,
sizeof(Ehdr64),
nil,
elfdotout },
{ MACH64_MAG, /* 64-bit MACH (apple mac) */
"mach executable",
nil,
FAMD64,
0,
&mamd64,
sizeof(Machhdr),
nil,
machdotout },
{ MACH32_MAG, /* 32-bit MACH (apple mac) */
"mach executable",
nil,
FI386,
0,
&mi386,
sizeof(Machhdr),
nil,
machdotout },
{ E_MAGIC, /* Arm 5.out and boot image */
"arm plan 9 executable",
"arm plan 9 dlm",
FARM,
1,
&marm,
sizeof(Exec),
beswal,
common },
{ (143<<16)|0413, /* (Free|Net)BSD Arm */
"arm *bsd executable",
nil,
FARM,
0,
&marm,
sizeof(Exec),
leswal,
armdotout },
{ L_MAGIC, /* alpha 7.out */
"alpha plan 9 executable",
"alpha plan 9 dlm",
FALPHA,
1,
&malpha,
sizeof(Exec),
beswal,
common },
{ 0x0700e0c3, /* alpha boot image */
"alpha plan 9 boot image",
nil,
FALPHA,
0,
&malpha,
sizeof(Exec),
beswal,
common },
{ 0 },
};
Mach *mach = &mi386; /* Global current machine table */
static ExecTable*
couldbe4k(ExecTable *mp)
{
Dir *d;
ExecTable *f;
if((d=dirstat("/proc/1/regs")) == nil)
return mp;
if(d->length < 32*8){ /* R3000 */
free(d);
return mp;
}
free(d);
for (f = exectab; f->magic; f++)
if(f->magic == M_MAGIC) {
f->name = "mips plan 9 executable on mips2 kernel";
return f;
}
return mp;
}
int
crackhdr(int fd, Fhdr *fp)
{
ExecTable *mp;
ExecHdr d;
int nb, ret;
uint32 magic;
fp->type = FNONE;
nb = read(fd, (char *)&d.e, sizeof(d.e));
if (nb <= 0)
return 0;
ret = 0;
magic = beswal(d.e.exechdr.magic); /* big-endian */
for (mp = exectab; mp->magic; mp++) {
if (nb < mp->hsize)
continue;
/*
* The magic number has morphed into something
* with fields (the straw was DYN_MAGIC) so now
* a flag is needed in Fhdr to distinguish _MAGIC()
* magic numbers from foreign magic numbers.
*
* This code is creaking a bit and if it has to
* be modified/extended much more it's probably
* time to step back and redo it all.
*/
if(mp->_magic){
if(mp->magic != (magic & ~DYN_MAGIC))
continue;
if(mp->magic == V_MAGIC)
mp = couldbe4k(mp);
if ((magic & DYN_MAGIC) && mp->dlmname != nil)
fp->name = mp->dlmname;
else
fp->name = mp->name;
}
else{
if(mp->magic != magic)
continue;
fp->name = mp->name;
}
fp->type = mp->type;
fp->hdrsz = mp->hsize; /* will be zero on bootables */
fp->_magic = mp->_magic;
fp->magic = magic;
mach = mp->mach;
if(mp->swal != nil)
hswal(&d, sizeof(d.e)/sizeof(uint32), mp->swal);
ret = mp->hparse(fd, fp, &d);
seek(fd, mp->hsize, 0); /* seek to end of header */
break;
}
if(mp->magic == 0)
werrstr("unknown header type");
return ret;
}
/*
* Convert header to canonical form
*/
static void
hswal(void *v, int n, uint32 (*swap)(uint32))
{
uint32 *ulp;
for(ulp = v; n--; ulp++)
*ulp = (*swap)(*ulp);
}
/*
* Crack a normal a.out-type header
*/
static int
adotout(int fd, Fhdr *fp, ExecHdr *hp)
{
int32 pgsize;
USED(fd);
pgsize = mach->pgsize;
settext(fp, hp->e.exechdr.entry, pgsize+sizeof(Exec),
hp->e.exechdr.text, sizeof(Exec));
setdata(fp, _round(pgsize+fp->txtsz+sizeof(Exec), pgsize),
hp->e.exechdr.data, fp->txtsz+sizeof(Exec), hp->e.exechdr.bss);
setsym(fp, fp->datoff+fp->datsz, hp->e.exechdr.syms, 0, hp->e.exechdr.spsz, 0, hp->e.exechdr.pcsz);
return 1;
}
static void
commonboot(Fhdr *fp)
{
if (!(fp->entry & mach->ktmask))
return;
switch(fp->type) { /* boot image */
case F68020:
fp->type = F68020B;
fp->name = "68020 plan 9 boot image";
break;
case FI386:
fp->type = FI386B;
fp->txtaddr = (u32int)fp->entry;
fp->name = "386 plan 9 boot image";
fp->dataddr = _round(fp->txtaddr+fp->txtsz, mach->pgsize);
break;
case FARM:
fp->type = FARMB;
fp->txtaddr = (u32int)fp->entry;
fp->name = "ARM plan 9 boot image";
fp->dataddr = _round(fp->txtaddr+fp->txtsz, mach->pgsize);
return;
case FALPHA:
fp->type = FALPHAB;
fp->txtaddr = (u32int)fp->entry;
fp->name = "alpha plan 9 boot image";
fp->dataddr = fp->txtaddr+fp->txtsz;
break;
case FPOWER:
fp->type = FPOWERB;
fp->txtaddr = (u32int)fp->entry;
fp->name = "power plan 9 boot image";
fp->dataddr = fp->txtaddr+fp->txtsz;
break;
case FAMD64:
fp->type = FAMD64B;
fp->txtaddr = fp->entry;
fp->name = "amd64 plan 9 boot image";
fp->dataddr = _round(fp->txtaddr+fp->txtsz, mach->pgsize);
break;
default:
return;
}
fp->hdrsz = 0; /* header stripped */
}
/*
* _MAGIC() style headers and
* alpha plan9-style bootable images for axp "headerless" boot
*
*/
static int
common(int fd, Fhdr *fp, ExecHdr *hp)
{
adotout(fd, fp, hp);
if(hp->e.exechdr.magic & DYN_MAGIC) {
fp->txtaddr = 0;
fp->dataddr = fp->txtsz;
return 1;
}
commonboot(fp);
return 1;
}
static int
commonllp64(int unused, Fhdr *fp, ExecHdr *hp)
{
int32 pgsize;
uvlong entry;
hswal(&hp->e, sizeof(Exec)/sizeof(int32), beswal);
if(!(hp->e.exechdr.magic & HDR_MAGIC))
return 0;
/*
* There can be more magic here if the
* header ever needs more expansion.
* For now just catch use of any of the
* unused bits.
*/
if((hp->e.exechdr.magic & ~DYN_MAGIC)>>16)
return 0;
union {
char *p;
uvlong *v;
} u;
u.p = (char*)&hp->e.exechdr;
entry = beswav(*u.v);
pgsize = mach->pgsize;
settext(fp, entry, pgsize+fp->hdrsz, hp->e.exechdr.text, fp->hdrsz);
setdata(fp, _round(pgsize+fp->txtsz+fp->hdrsz, pgsize),
hp->e.exechdr.data, fp->txtsz+fp->hdrsz, hp->e.exechdr.bss);
setsym(fp, fp->datoff+fp->datsz, hp->e.exechdr.syms, 0, hp->e.exechdr.spsz, 0, hp->e.exechdr.pcsz);
if(hp->e.exechdr.magic & DYN_MAGIC) {
fp->txtaddr = 0;
fp->dataddr = fp->txtsz;
return 1;
}
commonboot(fp);
return 1;
}
/*
* mips bootable image.
*/
static int
mipsboot(int fd, Fhdr *fp, ExecHdr *hp)
{
abort();
#ifdef unused
USED(fd);
fp->type = FMIPSB;
switch(hp->e.exechdr.amagic) {
default:
case 0407: /* some kind of mips */
settext(fp, (u32int)hp->e.mentry, (u32int)hp->e.text_start,
hp->e.tsize, sizeof(struct mipsexec)+4);
setdata(fp, (u32int)hp->e.data_start, hp->e.dsize,
fp->txtoff+hp->e.tsize, hp->e.bsize);
break;
case 0413: /* some kind of mips */
settext(fp, (u32int)hp->e.mentry, (u32int)hp->e.text_start,
hp->e.tsize, 0);
setdata(fp, (u32int)hp->e.data_start, hp->e.dsize,
hp->e.tsize, hp->e.bsize);
break;
}
setsym(fp, hp->e.nsyms, 0, hp->e.pcsize, hp->e.symptr);
fp->hdrsz = 0; /* header stripped */
#endif
return 1;
}
/*
* mips4k bootable image.
*/
static int
mips4kboot(int fd, Fhdr *fp, ExecHdr *hp)
{
abort();
#ifdef unused
USED(fd);
fp->type = FMIPSB;
switch(hp->e.h.amagic) {
default:
case 0407: /* some kind of mips */
settext(fp, (u32int)hp->e.h.mentry, (u32int)hp->e.h.text_start,
hp->e.h.tsize, sizeof(struct mips4kexec));
setdata(fp, (u32int)hp->e.h.data_start, hp->e.h.dsize,
fp->txtoff+hp->e.h.tsize, hp->e.h.bsize);
break;
case 0413: /* some kind of mips */
settext(fp, (u32int)hp->e.h.mentry, (u32int)hp->e.h.text_start,
hp->e.h.tsize, 0);
setdata(fp, (u32int)hp->e.h.data_start, hp->e.h.dsize,
hp->e.h.tsize, hp->e.h.bsize);
break;
}
setsym(fp, hp->e.h.nsyms, 0, hp->e.h.pcsize, hp->e.h.symptr);
fp->hdrsz = 0; /* header stripped */
#endif
return 1;
}
/*
* sparc bootable image
*/
static int
sparcboot(int fd, Fhdr *fp, ExecHdr *hp)
{
abort();
#ifdef unused
USED(fd);
fp->type = FSPARCB;
settext(fp, hp->e.sentry, hp->e.sentry, hp->e.stext,
sizeof(struct sparcexec));
setdata(fp, hp->e.sentry+hp->e.stext, hp->e.sdata,
fp->txtoff+hp->e.stext, hp->e.sbss);
setsym(fp, hp->e.ssyms, 0, hp->e.sdrsize, fp->datoff+hp->e.sdata);
fp->hdrsz = 0; /* header stripped */
#endif
return 1;
}
/*
* next bootable image
*/
static int
nextboot(int fd, Fhdr *fp, ExecHdr *hp)
{
abort();
#ifdef unused
USED(fd);
fp->type = FNEXTB;
settext(fp, hp->e.textc.vmaddr, hp->e.textc.vmaddr,
hp->e.texts.size, hp->e.texts.offset);
setdata(fp, hp->e.datac.vmaddr, hp->e.datas.size,
hp->e.datas.offset, hp->e.bsss.size);
setsym(fp, hp->e.symc.nsyms, hp->e.symc.spoff, hp->e.symc.pcoff,
hp->e.symc.symoff);
fp->hdrsz = 0; /* header stripped */
#endif
return 1;
}
/*
* Elf32 and Elf64 binaries.
*/
static int
elf64dotout(int fd, Fhdr *fp, ExecHdr *hp)
{
uvlong (*swav)(uvlong);
uint32 (*swal)(uint32);
ushort (*swab)(ushort);
Ehdr64 *ep;
Phdr64 *ph;
Shdr64 *sh;
int i, it, id, is, phsz, shsz;
/* bitswap the header according to the DATA format */
ep = &hp->e.elfhdr64;
if(ep->ident[CLASS] != ELFCLASS64) {
werrstr("bad ELF class - not 32 bit or 64 bit");
return 0;
}
if(ep->ident[DATA] == ELFDATA2LSB) {
swab = leswab;
swal = leswal;
swav = leswav;
} else if(ep->ident[DATA] == ELFDATA2MSB) {
swab = beswab;
swal = beswal;
swav = beswav;
} else {
werrstr("bad ELF encoding - not big or little endian");
return 0;
}
ep->type = swab(ep->type);
ep->machine = swab(ep->machine);
ep->version = swal(ep->version);
ep->elfentry = swal(ep->elfentry);
ep->phoff = swav(ep->phoff);
ep->shoff = swav(ep->shoff);
ep->flags = swav(ep->flags);
ep->ehsize = swab(ep->ehsize);
ep->phentsize = swab(ep->phentsize);
ep->phnum = swab(ep->phnum);
ep->shentsize = swab(ep->shentsize);
ep->shnum = swab(ep->shnum);
ep->shstrndx = swab(ep->shstrndx);
if(ep->type != EXEC || ep->version != CURRENT)
return 0;
/* we could definitely support a lot more machines here */
fp->magic = ELF_MAG;
fp->hdrsz = (ep->ehsize+ep->phnum*ep->phentsize+16)&~15;
switch(ep->machine) {
case AMD64:
mach = &mamd64;
fp->type = FAMD64;
break;
default:
return 0;
}
if(ep->phentsize != sizeof(Phdr64)) {
werrstr("bad ELF header size");
return 0;
}
phsz = sizeof(Phdr64)*ep->phnum;
ph = malloc(phsz);
if(!ph)
return 0;
seek(fd, ep->phoff, 0);
if(read(fd, ph, phsz) < 0) {
free(ph);
return 0;
}
hswal(ph, phsz/sizeof(uint32), swal);
shsz = sizeof(Shdr64)*ep->shnum;
sh = malloc(shsz);
if(sh) {
seek(fd, ep->shoff, 0);
if(read(fd, sh, shsz) < 0) {
free(sh);
sh = 0;
} else
hswal(sh, shsz/sizeof(uint32), swal);
}
/* find text, data and symbols and install them */
it = id = is = -1;
for(i = 0; i < ep->phnum; i++) {
if(ph[i].type == LOAD
&& (ph[i].flags & (R|X)) == (R|X) && it == -1)
it = i;
else if(ph[i].type == LOAD
&& (ph[i].flags & (R|W)) == (R|W) && id == -1)
id = i;
else if(ph[i].type == NOPTYPE && is == -1)
is = i;
}
if(it == -1 || id == -1) {
/*
* The SPARC64 boot image is something of an ELF hack.
* Text+Data+BSS are represented by ph[0]. Symbols
* are represented by ph[1]:
*
* filesz, memsz, vaddr, paddr, off
* ph[0] : txtsz+datsz, txtsz+datsz+bsssz, txtaddr-KZERO, datasize, txtoff
* ph[1] : symsz, lcsz, 0, 0, symoff
*/
if(ep->machine == SPARC64 && ep->phnum == 2) {
uint32 txtaddr, txtsz, dataddr, bsssz;
txtaddr = ph[0].vaddr | 0x80000000;
txtsz = ph[0].filesz - ph[0].paddr;
dataddr = txtaddr + txtsz;
bsssz = ph[0].memsz - ph[0].filesz;
settext(fp, ep->elfentry | 0x80000000, txtaddr, txtsz, ph[0].offset);
setdata(fp, dataddr, ph[0].paddr, ph[0].offset + txtsz, bsssz);
setsym(fp, ph[1].offset, ph[1].filesz, 0, 0, 0, ph[1].memsz);
free(ph);
return 1;
}
werrstr("No TEXT or DATA sections");
free(ph);
free(sh);
return 0;
}
settext(fp, ep->elfentry, ph[it].vaddr, ph[it].memsz, ph[it].offset);
setdata(fp, ph[id].vaddr, ph[id].filesz, ph[id].offset, ph[id].memsz - ph[id].filesz);
if(is != -1)
setsym(fp, ph[is].offset, ph[is].filesz, 0, 0, 0, ph[is].memsz);
else if(sh != 0){
char *buf;
uvlong symsize = 0;
uvlong symoff = 0;
uvlong pclnsz = 0;
uvlong pclnoff = 0;
/* load shstrtab names */
buf = malloc(sh[ep->shstrndx].size);
if (buf == 0)
goto done;
memset(buf, 0, sizeof buf);
seek(fd, sh[ep->shstrndx].offset, 0);
i = read(fd, buf, sh[ep->shstrndx].size);
USED(i); // shut up ubuntu gcc
for(i = 0; i < ep->shnum; i++) {
if (strcmp(&buf[sh[i].name], ".gosymtab") == 0) {
symsize = sh[i].size;
symoff = sh[i].offset;
}
if (strcmp(&buf[sh[i].name], ".gopclntab") == 0) {
pclnsz = sh[i].size;
pclnoff = sh[i].offset;
}
}
setsym(fp, symoff, symsize, 0, 0, pclnoff, pclnsz);
free(buf);
}
done:
free(ph);
free(sh);
return 1;
}
static int
elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
{
uint32 (*swal)(uint32);
ushort (*swab)(ushort);
Ehdr32 *ep;
Phdr32 *ph;
int i, it, id, is, phsz, shsz;
Shdr32 *sh;
/* bitswap the header according to the DATA format */
ep = &hp->e.elfhdr32;
if(ep->ident[CLASS] != ELFCLASS32) {
return elf64dotout(fd, fp, hp);
}
if(ep->ident[DATA] == ELFDATA2LSB) {
swab = leswab;
swal = leswal;
} else if(ep->ident[DATA] == ELFDATA2MSB) {
swab = beswab;
swal = beswal;
} else {
werrstr("bad ELF encoding - not big or little endian");
return 0;
}
ep->type = swab(ep->type);
ep->machine = swab(ep->machine);
ep->version = swal(ep->version);
ep->elfentry = swal(ep->elfentry);
ep->phoff = swal(ep->phoff);
ep->shoff = swal(ep->shoff);
ep->flags = swal(ep->flags);
ep->ehsize = swab(ep->ehsize);
ep->phentsize = swab(ep->phentsize);
ep->phnum = swab(ep->phnum);
ep->shentsize = swab(ep->shentsize);
ep->shnum = swab(ep->shnum);
ep->shstrndx = swab(ep->shstrndx);
if(ep->type != EXEC || ep->version != CURRENT)
return 0;
/* we could definitely support a lot more machines here */
fp->magic = ELF_MAG;
fp->hdrsz = (ep->ehsize+ep->phnum*ep->phentsize+16)&~15;
switch(ep->machine) {
case I386:
mach = &mi386;
fp->type = FI386;
break;
case MIPS:
mach = &mmips;
fp->type = FMIPS;
break;
case SPARC64:
mach = &msparc64;
fp->type = FSPARC64;
break;
case POWER:
mach = &mpower;
fp->type = FPOWER;
break;
case ARM:
mach = &marm;
fp->type = FARM;
break;
default:
return 0;
}
if(ep->phentsize != sizeof(Phdr32)) {
werrstr("bad ELF header size");
return 0;
}
phsz = sizeof(Phdr32)*ep->phnum;
ph = malloc(phsz);
if(!ph)
return 0;
seek(fd, ep->phoff, 0);
if(read(fd, ph, phsz) < 0) {
free(ph);
return 0;
}
hswal(ph, phsz/sizeof(uint32), swal);
shsz = sizeof(Shdr32)*ep->shnum;
sh = malloc(shsz);
if(sh) {
seek(fd, ep->shoff, 0);
if(read(fd, sh, shsz) < 0) {
free(sh);
sh = 0;
} else
hswal(sh, shsz/sizeof(uint32), swal);
}
/* find text, data and symbols and install them */
it = id = is = -1;
for(i = 0; i < ep->phnum; i++) {
if(ph[i].type == LOAD
&& (ph[i].flags & (R|X)) == (R|X) && it == -1)
it = i;
else if(ph[i].type == LOAD
&& (ph[i].flags & (R|W)) == (R|W) && id == -1)
id = i;
else if(ph[i].type == NOPTYPE && is == -1)
is = i;
}
if(it == -1 || id == -1) {
/*
* The SPARC64 boot image is something of an ELF hack.
* Text+Data+BSS are represented by ph[0]. Symbols
* are represented by ph[1]:
*
* filesz, memsz, vaddr, paddr, off
* ph[0] : txtsz+datsz, txtsz+datsz+bsssz, txtaddr-KZERO, datasize, txtoff
* ph[1] : symsz, lcsz, 0, 0, symoff
*/
if(ep->machine == SPARC64 && ep->phnum == 2) {
uint32 txtaddr, txtsz, dataddr, bsssz;
txtaddr = ph[0].vaddr | 0x80000000;
txtsz = ph[0].filesz - ph[0].paddr;
dataddr = txtaddr + txtsz;
bsssz = ph[0].memsz - ph[0].filesz;
settext(fp, ep->elfentry | 0x80000000, txtaddr, txtsz, ph[0].offset);
setdata(fp, dataddr, ph[0].paddr, ph[0].offset + txtsz, bsssz);
setsym(fp, ph[1].offset, ph[1].filesz, 0, 0, 0, ph[1].memsz);
free(ph);
return 1;
}
werrstr("No TEXT or DATA sections");
free(sh);
free(ph);
return 0;
}
settext(fp, ep->elfentry, ph[it].vaddr, ph[it].memsz, ph[it].offset);
setdata(fp, ph[id].vaddr, ph[id].filesz, ph[id].offset, ph[id].memsz - ph[id].filesz);
if(is != -1)
setsym(fp, ph[is].offset, ph[is].filesz, 0, 0, 0, ph[is].memsz);
else if(sh != 0){
char *buf;
uvlong symsize = 0;
uvlong symoff = 0;
uvlong pclnsize = 0;
uvlong pclnoff = 0;
/* load shstrtab names */
buf = malloc(sh[ep->shstrndx].size);
if (buf == 0)
goto done;
memset(buf, 0, sizeof buf);
seek(fd, sh[ep->shstrndx].offset, 0);
i = read(fd, buf, sh[ep->shstrndx].size);
USED(i); // shut up ubuntu gcc
for(i = 0; i < ep->shnum; i++) {
if (strcmp(&buf[sh[i].name], ".gosymtab") == 0) {
symsize = sh[i].size;
symoff = sh[i].offset;
}
if (strcmp(&buf[sh[i].name], ".gopclntab") == 0) {
pclnsize = sh[i].size;
pclnoff = sh[i].offset;
}
}
setsym(fp, symoff, symsize, 0, 0, pclnoff, pclnsize);
free(buf);
}
done:
free(sh);
free(ph);
return 1;
}
static int
machdotout(int fd, Fhdr *fp, ExecHdr *hp)
{
uvlong (*swav)(uvlong);
uint32 (*swal)(uint32);
ushort (*swab)(ushort);
Machhdr *mp;
MachCmd **cmd;
MachSymSeg *symtab;
MachSymSeg *pclntab;
MachSeg64 *seg;
MachSect64 *sect;
MachSeg32 *seg32;
MachSect32 *sect32;
uvlong textsize, datasize, bsssize;
uchar *cmdbuf;
uchar *cmdp;
int i, hdrsize;
uint32 textva, textoff, datava, dataoff;
mp = &hp->e.machhdr;
if (leswal(mp->filetype) != MACH_EXECUTABLE_TYPE) {
werrstr("bad MACH executable type %#ux", leswal(mp->filetype));
return 0;
}
swab = leswab;
swal = leswal;
swav = leswav;
mp->magic = swal(mp->magic);
mp->cputype = swal(mp->cputype);
mp->cpusubtype = swal(mp->cpusubtype);
mp->filetype = swal(mp->filetype);
mp->ncmds = swal(mp->ncmds);
mp->sizeofcmds = swal(mp->sizeofcmds);
mp->flags = swal(mp->flags);
mp->reserved = swal(mp->reserved);
hdrsize = 0;
switch(mp->magic) {
case 0xFEEDFACE: // 32-bit mach
if (mp->cputype != MACH_CPU_TYPE_X86) {
werrstr("bad MACH cpu type - not 386");
return 0;
}
if (mp->cpusubtype != MACH_CPU_SUBTYPE_X86) {
werrstr("bad MACH cpu subtype - not 386");
return 0;
}
if (mp->filetype != MACH_EXECUTABLE_TYPE) {
werrstr("bad MACH executable type");
return 0;
}
mach = &mi386;
fp->type = FI386;
hdrsize = 28;
break;
case 0xFEEDFACF: // 64-bit mach
if (mp->cputype != MACH_CPU_TYPE_X86_64) {
werrstr("bad MACH cpu type - not amd64");
return 0;
}
if (mp->cpusubtype != MACH_CPU_SUBTYPE_X86) {
werrstr("bad MACH cpu subtype - not amd64");
return 0;
}
mach = &mamd64;
fp->type = FAMD64;
hdrsize = 32;
break;
default:
werrstr("not mach %#ux", mp->magic);
return 0;
}
cmdbuf = malloc(mp->sizeofcmds);
seek(fd, hdrsize, 0);
if(read(fd, cmdbuf, mp->sizeofcmds) != mp->sizeofcmds) {
free(cmdbuf);
return 0;
}
cmd = malloc(mp->ncmds * sizeof(MachCmd*));
cmdp = cmdbuf;
textva = 0;
textoff = 0;
dataoff = 0;
datava = 0;
symtab = 0;
pclntab = 0;
textsize = datasize = bsssize = 0;
for (i = 0; i < mp->ncmds; i++) {
MachCmd *c;
cmd[i] = (MachCmd*)cmdp;
c = cmd[i];
c->type = swal(c->type);
c->size = swal(c->size);
switch(c->type) {
case MACH_SEGMENT_32:
if(mp->magic != 0xFEEDFACE) {
werrstr("segment 32 in mach 64");
goto bad;
}
seg32 = (MachSeg32*)c;
seg32->vmaddr = swav(seg32->vmaddr);
seg32->vmsize = swav(seg32->vmsize);
seg32->fileoff = swav(seg32->fileoff);
seg32->filesize = swav(seg32->filesize);
seg32->maxprot = swal(seg32->maxprot);
seg32->initprot = swal(seg32->initprot);
seg32->nsects = swal(seg32->nsects);
seg32->flags = swal(seg32->flags);
if (strcmp(seg32->segname, "__TEXT") == 0) {
textva = seg32->vmaddr;
textoff = seg32->fileoff;
sect32 = (MachSect32*)(cmdp + sizeof(MachSeg32));
if (strcmp(sect32->sectname, "__text") == 0) {
textsize = swal(sect32->size);
} else {
werrstr("no text section");
goto bad;
}
}
if (strcmp(seg32->segname, "__DATA") == 0) {
datava = seg32->vmaddr;
dataoff = seg32->fileoff;
sect32 = (MachSect32*)(cmdp + sizeof(MachSeg32));
if (strcmp(sect32->sectname, "__data") == 0) {
datasize = swal(sect32->size);
} else {
werrstr("no data section");
goto bad;
}
sect32++;
if (strcmp(sect32->sectname, "__nl_symbol_ptr") == 0)
sect32++;
if (strcmp(sect32->sectname, "__bss") == 0) {
bsssize = swal(sect32->size);
} else {
werrstr("no bss section");
goto bad;
}
}
break;
case MACH_SEGMENT_64:
if(mp->magic != 0xFEEDFACF) {
werrstr("segment 32 in mach 64");
goto bad;
}
seg = (MachSeg64*)c;
seg->vmaddr = swav(seg->vmaddr);
seg->vmsize = swav(seg->vmsize);
seg->fileoff = swav(seg->fileoff);
seg->filesize = swav(seg->filesize);
seg->maxprot = swal(seg->maxprot);
seg->initprot = swal(seg->initprot);
seg->nsects = swal(seg->nsects);
seg->flags = swal(seg->flags);
if (strcmp(seg->segname, "__TEXT") == 0) {
textva = seg->vmaddr;
textoff = seg->fileoff;
sect = (MachSect64*)(cmdp + sizeof(MachSeg64));
if (strcmp(sect->sectname, "__text") == 0) {
textsize = swav(sect->size);
} else {
werrstr("no text section");
goto bad;
}
}
if (strcmp(seg->segname, "__DATA") == 0) {
datava = seg->vmaddr;
dataoff = seg->fileoff;
sect = (MachSect64*)(cmdp + sizeof(MachSeg64));
if (strcmp(sect->sectname, "__data") == 0) {
datasize = swav(sect->size);
} else {
werrstr("no data section");
goto bad;
}
sect++;
if (strcmp(sect->sectname, "__nl_symbol_ptr") == 0)
sect++;
if (strcmp(sect->sectname, "__bss") == 0) {
bsssize = swav(sect->size);
} else {
werrstr("no bss section");
goto bad;
}
}
break;
case MACH_UNIXTHREAD:
break;
case MACH_SYMSEG:
if (symtab == 0)
symtab = (MachSymSeg*)c;
else if (pclntab == 0)
pclntab = (MachSymSeg*)c;
break;
}
cmdp += c->size;
}
if (textva == 0 || datava == 0) {
free(cmd);
free(cmdbuf);
return 0;
}
/* compute entry by taking address after header - weird - BUG? */
settext(fp, textva+sizeof(Machhdr) + mp->sizeofcmds, textva, textsize, textoff);
setdata(fp, datava, datasize, dataoff, bsssize);
if(symtab != 0)
setsym(fp, symtab->fileoff, symtab->filesize, 0, 0, 0, pclntab? pclntab->filesize : 0);
free(cmd);
free(cmdbuf);
return 1;
bad:
free(cmd);
free(cmdbuf);
return 0;
}
/*
* (Free|Net)BSD ARM header.
*/
static int
armdotout(int fd, Fhdr *fp, ExecHdr *hp)
{
uvlong kbase;
USED(fd);
settext(fp, hp->e.exechdr.entry, sizeof(Exec), hp->e.exechdr.text, sizeof(Exec));
setdata(fp, fp->txtsz, hp->e.exechdr.data, fp->txtsz, hp->e.exechdr.bss);
setsym(fp, fp->datoff+fp->datsz, hp->e.exechdr.syms, 0, hp->e.exechdr.spsz, 0, hp->e.exechdr.pcsz);
kbase = 0xF0000000;
if ((fp->entry & kbase) == kbase) { /* Boot image */
fp->txtaddr = kbase+sizeof(Exec);
fp->name = "ARM *BSD boot image";
fp->hdrsz = 0; /* header stripped */
fp->dataddr = kbase+fp->txtsz;
}
return 1;
}
static void
settext(Fhdr *fp, uvlong e, uvlong a, int32 s, vlong off)
{
fp->txtaddr = a;
fp->entry = e;
fp->txtsz = s;
fp->txtoff = off;
}
static void
setdata(Fhdr *fp, uvlong a, int32 s, vlong off, int32 bss)
{
fp->dataddr = a;
fp->datsz = s;
fp->datoff = off;
fp->bsssz = bss;
}
static void
setsym(Fhdr *fp, vlong symoff, int32 symsz, vlong sppcoff, int32 sppcsz, vlong lnpcoff, int32 lnpcsz)
{
fp->symoff = symoff;
fp->symsz = symsz;
if(sppcoff == 0)
sppcoff = symoff+symsz;
fp->sppcoff = symoff;
fp->sppcsz = sppcsz;
if(lnpcoff == 0)
lnpcoff = sppcoff + sppcsz;
fp->lnpcoff = lnpcoff;
fp->lnpcsz = lnpcsz;
}
static uvlong
_round(uvlong a, uint32 b)
{
uvlong w;
w = (a/b)*b;
if (a!=w)
w += b;
return(w);
}
View Git Blame Copy Permalink