#include <config.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <stdio.h>
#include <errno.h>
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#if !defined (__NetBSD__) && !defined (__OpenBSD__)
#include <filehdr.h>
#include <aouthdr.h>
#include <scnhdr.h>
#include <syms.h>
#ifndef __linux__
# include <reloc.h>
# include <elf_abi.h>
#endif
#else
#include <sys/exec_ecoff.h>
#define filehdr ecoff_filehdr
#define aouthdr ecoff_aouthdr
#define scnhdr ecoff_scnhdr
#define HDRR struct ecoff_symhdr
#define pHDRR HDRR *
#define cbHDRR sizeof(HDRR)
#ifdef __OpenBSD__
#define ALPHAMAGIC ECOFF_MAGIC_NATIVE_ALPHA
#else
#define ALPHAMAGIC ECOFF_MAGIC_NETBSD_ALPHA
#endif
#define ZMAGIC ECOFF_ZMAGIC
#define ALPHAUMAGIC 0617
#define _MIPS_NSCNS_MAX 35
#define STYP_TEXT 0x00000020
#define STYP_DATA 0x00000040
#define STYP_BSS 0x00000080
#define STYP_RDATA 0x00000100
#define STYP_SDATA 0x00000200
#define STYP_SBSS 0x00000400
#define STYP_INIT 0x80000000
#define _TEXT ".text"
#define _DATA ".data"
#define _BSS ".bss"
#define _INIT ".init"
#define _RDATA ".rdata"
#define _SDATA ".sdata"
#define _SBSS ".sbss"
#endif
static void fatal_unexec __P ((char *, char *));
static void mark_x __P ((char *));
static void update_dynamic_symbols __P ((char *, char *, int, struct aouthdr));
#define READ(_fd, _buffer, _size, _error_message, _error_arg) \
errno = EEOF; \
if (read (_fd, _buffer, _size) != _size) \
fatal_unexec (_error_message, _error_arg);
#define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \
if (write (_fd, _buffer, _size) != _size) \
fatal_unexec (_error_message, _error_arg);
#define SEEK(_fd, _position, _error_message, _error_arg) \
errno = EEOF; \
if (lseek (_fd, _position, L_SET) != _position) \
fatal_unexec (_error_message, _error_arg);
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#else
void *sbrk ();
#endif
#define EEOF -1
static struct scnhdr *text_section;
static struct scnhdr *rel_dyn_section;
static struct scnhdr *dynstr_section;
static struct scnhdr *dynsym_section;
static struct scnhdr *init_section;
static struct scnhdr *finit_section;
static struct scnhdr *rdata_section;
static struct scnhdr *rconst_section;
static struct scnhdr *data_section;
static struct scnhdr *pdata_section;
static struct scnhdr *xdata_section;
static struct scnhdr *got_section;
static struct scnhdr *lit8_section;
static struct scnhdr *lit4_section;
static struct scnhdr *sdata_section;
static struct scnhdr *sbss_section;
static struct scnhdr *bss_section;
static struct scnhdr old_data_scnhdr;
static unsigned long Brk;
struct headers {
struct filehdr fhdr;
struct aouthdr aout;
struct scnhdr section[_MIPS_NSCNS_MAX];
};
#ifndef DEFAULT_ENTRY_ADDRESS
#define DEFAULT_ENTRY_ADDRESS __start
#endif
void
unexec (new_name, a_name, data_start, bss_start, entry_address)
char *new_name, *a_name;
unsigned long data_start, bss_start, entry_address;
{
int new, old;
char * oldptr;
struct headers ohdr, nhdr;
struct stat stat;
long pagesize, brk;
long newsyms, symrel;
int nread;
int i;
long vaddr, scnptr;
#define BUFSIZE 8192
char buffer[BUFSIZE];
if ((old = open (a_name, O_RDONLY)) < 0)
fatal_unexec ("opening %s", a_name);
new = creat (new_name, 0666);
if (new < 0) fatal_unexec ("creating %s", new_name);
if ((fstat (old, &stat) == -1))
fatal_unexec ("fstat %s", a_name);
oldptr = (char *)mmap (0, stat.st_size, PROT_READ, MAP_FILE|MAP_SHARED, old, 0);
if (oldptr == (char *)-1)
fatal_unexec ("mmap %s", a_name);
close (old);
ohdr = (*(struct headers *)oldptr);
nhdr = *((struct headers *)TEXT_START);
if (nhdr.fhdr.f_magic != ALPHAMAGIC
&& nhdr.fhdr.f_magic != ALPHAUMAGIC)
{
fprintf (stderr, "unexec: input file magic number is %x, not %x or %x.\n",
nhdr.fhdr.f_magic, ALPHAMAGIC, ALPHAUMAGIC);
exit (1);
}
if (nhdr.fhdr.f_opthdr != sizeof (nhdr.aout))
{
fprintf (stderr, "unexec: input a.out header is %d bytes, not %d.\n",
nhdr.fhdr.f_opthdr, (int)sizeof (nhdr.aout));
exit (1);
}
if (nhdr.aout.magic != ZMAGIC)
{
fprintf (stderr, "unexec: input file a.out magic number is %o, not %o.\n",
nhdr.aout.magic, ZMAGIC);
exit (1);
}
#define CHECK_SCNHDR(ptr, name, flags) \
ptr = NULL; \
for (i = 0; i < nhdr.fhdr.f_nscns && !ptr; i++) \
if (strncmp (nhdr.section[i].s_name, name, 8) == 0) \
{ \
if (nhdr.section[i].s_flags != flags) \
fprintf (stderr, "unexec: %x flags (%x expected) in %s section.\n", \
nhdr.section[i].s_flags, flags, name); \
ptr = nhdr.section + i; \
} \
CHECK_SCNHDR (text_section, _TEXT, STYP_TEXT);
CHECK_SCNHDR (init_section, _INIT, STYP_INIT);
#ifdef _REL_DYN
CHECK_SCNHDR (rel_dyn_section, _REL_DYN, STYP_REL_DYN);
#endif
#ifdef _DYNSYM
CHECK_SCNHDR (dynsym_section, _DYNSYM, STYP_DYNSYM);
#endif
#ifdef _DYNSTR
CHECK_SCNHDR (dynstr_section, _DYNSTR, STYP_DYNSTR);
#endif
#ifdef _FINI
CHECK_SCNHDR (finit_section, _FINI, STYP_FINI);
#endif
CHECK_SCNHDR (rdata_section, _RDATA, STYP_RDATA);
#ifdef _RCONST
CHECK_SCNHDR (rconst_section, _RCONST, STYP_RCONST);
#endif
#ifdef _PDATA
CHECK_SCNHDR (pdata_section, _PDATA, STYP_PDATA);
#endif
#ifdef _GOT
CHECK_SCNHDR (got_section, _GOT, STYP_GOT);
#endif
CHECK_SCNHDR (data_section, _DATA, STYP_DATA);
#ifdef _XDATA
CHECK_SCNHDR (xdata_section, _XDATA, STYP_XDATA);
#endif
#ifdef _LIT8
CHECK_SCNHDR (lit8_section, _LIT8, STYP_LIT8);
CHECK_SCNHDR (lit4_section, _LIT4, STYP_LIT4);
#endif
CHECK_SCNHDR (sdata_section, _SDATA, STYP_SDATA);
CHECK_SCNHDR (sbss_section, _SBSS, STYP_SBSS);
CHECK_SCNHDR (bss_section, _BSS, STYP_BSS);
pagesize = getpagesize ();
brk = (((long) (sbrk (0))) + pagesize - 1) & (-pagesize);
Brk = brk;
bcopy (data_section, &old_data_scnhdr, sizeof (old_data_scnhdr));
nhdr.aout.dsize = brk - DATA_START;
nhdr.aout.bsize = 0;
if (entry_address == 0)
{
extern DEFAULT_ENTRY_ADDRESS ();
nhdr.aout.entry = (unsigned long)DEFAULT_ENTRY_ADDRESS;
}
else
nhdr.aout.entry = entry_address;
nhdr.aout.bss_start = nhdr.aout.data_start + nhdr.aout.dsize;
if (rdata_section != NULL)
{
rdata_section->s_size = data_start - DATA_START;
rdata_section->s_vaddr = DATA_START;
rdata_section->s_paddr = DATA_START;
rdata_section->s_scnptr = text_section->s_scnptr + nhdr.aout.tsize;
}
data_section->s_vaddr = data_start;
data_section->s_paddr = data_start;
data_section->s_size = brk - data_start;
if (rdata_section != NULL)
{
data_section->s_scnptr = rdata_section->s_scnptr + rdata_section->s_size;
}
vaddr = data_section->s_vaddr + data_section->s_size;
scnptr = data_section->s_scnptr + data_section->s_size;
if (lit8_section != NULL)
{
lit8_section->s_vaddr = vaddr;
lit8_section->s_paddr = vaddr;
lit8_section->s_size = 0;
lit8_section->s_scnptr = scnptr;
}
if (lit4_section != NULL)
{
lit4_section->s_vaddr = vaddr;
lit4_section->s_paddr = vaddr;
lit4_section->s_size = 0;
lit4_section->s_scnptr = scnptr;
}
if (sdata_section != NULL)
{
sdata_section->s_vaddr = vaddr;
sdata_section->s_paddr = vaddr;
sdata_section->s_size = 0;
sdata_section->s_scnptr = scnptr;
}
#ifdef _XDATA
if (xdata_section != NULL)
{
xdata_section->s_vaddr = vaddr;
xdata_section->s_paddr = vaddr;
xdata_section->s_size = 0;
xdata_section->s_scnptr = scnptr;
}
#endif
#ifdef _GOT
if (got_section != NULL)
{
bcopy (got_section, buffer, sizeof (struct scnhdr));
got_section->s_vaddr = vaddr;
got_section->s_paddr = vaddr;
got_section->s_size = 0;
got_section->s_scnptr = scnptr;
}
#endif
if (sbss_section != NULL)
{
sbss_section->s_vaddr = vaddr;
sbss_section->s_paddr = vaddr;
sbss_section->s_size = 0;
sbss_section->s_scnptr = scnptr;
}
if (bss_section != NULL)
{
bss_section->s_vaddr = vaddr;
bss_section->s_paddr = vaddr;
bss_section->s_size = 0;
bss_section->s_scnptr = scnptr;
}
WRITE (new, (char *)TEXT_START, nhdr.aout.tsize,
"writing text section to %s", new_name);
WRITE (new, (char *)DATA_START, nhdr.aout.dsize,
"writing data section to %s", new_name);
#ifdef _GOT
#define old_got_section ((struct scnhdr *)buffer)
if (got_section != NULL)
{
SEEK (new, old_got_section->s_scnptr,
"seeking to start of got_section in %s", new_name);
WRITE (new, oldptr + old_got_section->s_scnptr, old_got_section->s_size,
"writing new got_section of %s", new_name);
SEEK (new, nhdr.aout.tsize + nhdr.aout.dsize,
"seeking to end of data section of %s", new_name);
}
#undef old_got_section
#endif
bcopy (oldptr + nhdr.fhdr.f_symptr, buffer, cbHDRR);
#define symhdr ((pHDRR)buffer)
newsyms = nhdr.aout.tsize + nhdr.aout.dsize;
symrel = newsyms - nhdr.fhdr.f_symptr;
nhdr.fhdr.f_symptr = newsyms;
symhdr->cbLineOffset += symrel;
symhdr->cbDnOffset += symrel;
symhdr->cbPdOffset += symrel;
symhdr->cbSymOffset += symrel;
symhdr->cbOptOffset += symrel;
symhdr->cbAuxOffset += symrel;
symhdr->cbSsOffset += symrel;
symhdr->cbSsExtOffset += symrel;
symhdr->cbFdOffset += symrel;
symhdr->cbRfdOffset += symrel;
symhdr->cbExtOffset += symrel;
WRITE (new, buffer, cbHDRR, "writing symbol table header of %s", new_name);
WRITE (new, oldptr + ohdr.fhdr.f_symptr + cbHDRR,
stat.st_size - ohdr.fhdr.f_symptr - cbHDRR,
"writing symbol table of %s", new_name);
#ifdef _REL_DYN
if (rel_dyn_section)
update_dynamic_symbols (oldptr, new_name, new, nhdr.aout);
#endif
#undef symhdr
SEEK (new, 0, "seeking to start of header in %s", new_name);
WRITE (new, &nhdr, sizeof (nhdr),
"writing header of %s", new_name);
close (old);
close (new);
mark_x (new_name);
}
static void
update_dynamic_symbols (old, new_name, new, aout)
char *old;
char *new_name;
int new;
struct aouthdr aout;
{
#if !defined (__linux__) && !defined (__NetBSD__) && !defined (__OpenBSD__)
typedef struct dynrel_info {
char * addr;
unsigned type:8;
unsigned index:24;
unsigned info:8;
unsigned pad:8;
} dr_info;
int nsyms = rel_dyn_section->s_size / sizeof (struct dynrel_info);
int i;
dr_info * rd_base = (dr_info *) (old + rel_dyn_section->s_scnptr);
Elf32_Sym * ds_base = (Elf32_Sym *) (old + dynsym_section->s_scnptr);
for (i = 0; i < nsyms; i++) {
register Elf32_Sym x;
if (rd_base[i].index == 0)
continue;
x = ds_base[rd_base[i].index];
#if 0
fprintf (stderr, "Object inspected: %s, addr = %lx, shndx = %x",
old + dynstr_section->s_scnptr + x.st_name, rd_base[i].addr, x.st_shndx);
#endif
if ((ELF32_ST_BIND (x.st_info) == STB_GLOBAL)
&& (x.st_shndx == 0)
) {
register unsigned long reladdr = (long)rd_base[i].addr - old_data_scnhdr.s_vaddr;
char * oldref = old + old_data_scnhdr.s_scnptr + reladdr;
unsigned long newref = aout.tsize + reladdr;
int len;
#if 0
fprintf (stderr, "...relocated\n");
#endif
if (rd_base[i].type == R_REFLONG)
len = 4;
else if (rd_base[i].type == R_REFQUAD)
len = 8;
else
fatal_unexec ("unrecognized relocation type in .dyn.rel section (symbol #%d)", (char *) i);
SEEK (new, newref, "seeking to dynamic symbol in %s", new_name);
WRITE (new, oldref, len, "writing old dynrel info in %s", new_name);
}
#if 0
else
fprintf (stderr, "...not relocated\n");
#endif
}
#endif
}
static void
mark_x (name)
char *name;
{
struct stat sbuf;
int um = umask (777);
umask (um);
if (stat (name, &sbuf) < 0)
fatal_unexec ("getting protection on %s", name);
sbuf.st_mode |= 0111 & ~um;
if (chmod (name, sbuf.st_mode) < 0)
fatal_unexec ("setting protection on %s", name);
}
static void
fatal_unexec (s, arg)
char *s;
char *arg;
{
if (errno == EEOF)
fputs ("unexec: unexpected end of file, ", stderr);
else
fprintf (stderr, "unexec: %s, ", strerror (errno));
fprintf (stderr, s, arg);
fputs (".\n", stderr);
exit (1);
}