OpenBSD-4.6/usr.bin/strip/strip.c
/* $OpenBSD: strip.c,v 1.25 2009/06/19 09:40:43 sobrado Exp $ */
/*
* Copyright (c) 1988 Regents of the University of California.
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
/*static char sccsid[] = "from: @(#)strip.c 5.8 (Berkeley) 11/6/91";*/
static char rcsid[] = "$OpenBSD: strip.c,v 1.25 2009/06/19 09:40:43 sobrado Exp $";
#endif /* not lint */
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <errno.h>
#include <a.out.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include <ranlib.h>
#include "byte.c"
#ifdef MID_MACHINE_OVERRIDE
#undef MID_MACHINE
#define MID_MACHINE MID_MACHINE_OVERRIDE
#if MID_MACHINE_OVERRIDE == MID_M68K
#undef __LDPGSZ
#undef ELF_TARG_DATA
#undef ELF_TARG_MACH
#include "m68k/exec.h"
#elif MID_MACHINE_OVERRIDE == MID_M88K
#undef __LDPGSZ
#undef ELF_TARG_DATA
#undef ELF_TARG_MACH
#include "m88k/exec.h"
#endif
#endif
typedef struct exec EXEC;
typedef struct nlist NLIST;
#define strx n_un.n_strx
int s_stab(const char *, int, EXEC *, struct stat *, off_t *);
int s_sym(const char *, int, EXEC *, struct stat *, off_t *);
void usage(void);
int xflag = 0;
int
main(int argc, char *argv[])
{
int fd;
EXEC *ep;
struct stat sb;
int (*sfcn)(const char *, int, EXEC *, struct stat *, off_t *);
int ch, errors;
char *fn;
off_t newsize;
sfcn = s_sym;
while ((ch = getopt(argc, argv, "dx")) != -1)
switch(ch) {
case 'x':
xflag = 1;
/*FALLTHROUGH*/
case 'd':
sfcn = s_stab;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
errors = 0;
#define ERROR(x) errors |= 1; warnx("%s: %s", fn, strerror(x)); continue;
while ((fn = *argv++)) {
if ((fd = open(fn, O_RDWR)) < 0) {
ERROR(errno);
}
if (fstat(fd, &sb)) {
(void)close(fd);
ERROR(errno);
}
if (sb.st_size < sizeof(EXEC)) {
(void)close(fd);
ERROR(EFTYPE);
}
if ((ep = (EXEC *)mmap(NULL, sb.st_size, PROT_READ|PROT_WRITE,
MAP_SHARED, fd, (off_t)0)) == MAP_FAILED) {
(void)close(fd);
ERROR(errno);
}
if (BAD_OBJECT(*ep)) {
munmap((caddr_t)ep, sb.st_size);
(void)close(fd);
ERROR(EFTYPE);
}
/*
* Since we're dealing with an mmap there, we have to convert
* once for dealing with data in memory, and a second time
* for out.
*/
fix_header_order(ep);
newsize = 0;
errors |= sfcn(fn, fd, ep, &sb, &newsize);
fix_header_order(ep);
munmap((caddr_t)ep, sb.st_size);
if (newsize && ftruncate(fd, newsize)) {
warn("%s", fn);
errors = 1;
}
if (close(fd)) {
ERROR(errno);
}
}
#undef ERROR
exit(errors);
}
int
s_sym(const char *fn, int fd, EXEC *ep, struct stat *sp, off_t *sz)
{
char *neweof;
#if 0
char *mineof;
#endif
int zmagic;
zmagic = ep->a_data &&
(N_GETMAGIC(*ep) == ZMAGIC || N_GETMAGIC(*ep) == QMAGIC);
/*
* If no symbols or data/text relocation info and
* the file data segment size is already minimized, quit.
*/
if (!ep->a_syms && !ep->a_trsize && !ep->a_drsize) {
#if 0
if (!zmagic)
return 0;
if (sp->st_size < N_TRELOFF(*ep))
#endif
return 0;
}
/*
* New file size is the header plus text and data segments; OMAGIC
* and NMAGIC formats have the text/data immediately following the
* header. ZMAGIC format wastes the rest of of header page.
*/
neweof = (char *)ep + N_TRELOFF(*ep);
#if 0
/*
* Unfortunately, this can't work correctly without changing the way
* the loader works. We could cap it at one page, or even fiddle with
* a_data and a_bss, but this only works for CLBYTES == NBPG. If we
* are on a system where, e.g., CLBYTES is 8k and NBPG is 4k, and we
* happen to remove 4.5k, we will lose. And we really don't want to
* fiddle with pages, because that breaks binary compatibility. Lose.
*/
if (zmagic) {
/*
* Get rid of unneeded zeroes at the end of the data segment
* to reduce the file size even more.
*/
mineof = (char *)ep + N_DATOFF(*ep);
while (neweof > mineof && neweof[-1] == '\0')
neweof--;
}
#endif
/* Set symbol size and relocation info values to 0. */
ep->a_syms = ep->a_trsize = ep->a_drsize = 0;
/* Truncate the file. */
*sz = neweof - (char *)ep;
return 0;
}
int
s_stab(const char *fn, int fd, EXEC *ep, struct stat *sp, off_t *sz)
{
int cnt, len;
char *nstr, *nstrbase=0, *used=0, *p, *strbase;
NLIST *sym, *nsym;
u_long allocsize;
int mid;
NLIST *symbase;
unsigned int *mapping=0;
int error=1;
unsigned int nsyms;
struct relocation_info *reloc_base;
unsigned int i, j;
/* Quit if no symbols. */
if (ep->a_syms == 0)
return 0;
if (N_SYMOFF(*ep) >= sp->st_size) {
warnx("%s: bad symbol table", fn);
return 1;
}
mid = N_GETMID(*ep);
/*
* Initialize old and new symbol pointers. They both point to the
* beginning of the symbol table in memory, since we're deleting
* entries.
*/
sym = nsym = symbase = (NLIST *)((char *)ep + N_SYMOFF(*ep));
/*
* Allocate space for the new string table, initialize old and
* new string pointers. Handle the extra long at the beginning
* of the string table.
*/
strbase = (char *)ep + N_STROFF(*ep);
allocsize = fix_32_order(*(u_long *)strbase, mid);
if ((nstrbase = malloc((u_int) allocsize)) == NULL) {
warnx("%s", strerror(ENOMEM));
goto end;
}
nstr = nstrbase + sizeof(u_long);
/* okay, so we also need to keep symbol numbers for relocations. */
nsyms = ep->a_syms/ sizeof(NLIST);
used = calloc(nsyms, 1);
if (!used) {
warnx("%s", strerror(ENOMEM));
goto end;
}
mapping = calloc(nsyms, sizeof(unsigned int));
if (!mapping) {
warnx("%s", strerror(ENOMEM));
goto end;
}
if ((ep->a_trsize || ep->a_drsize) && byte_sex(mid) != BYTE_ORDER) {
warnx("%s: cross-stripping not supported", fn);
goto end;
}
/* first check the relocations for used symbols, and mark them */
/* text */
reloc_base = (struct relocation_info *) ((char *)ep + N_TRELOFF(*ep));
if (N_TRELOFF(*ep) + ep->a_trsize > sp->st_size) {
warnx("%s: bad text relocation", fn);
goto end;
}
for (i = 0; i < ep->a_trsize / sizeof(struct relocation_info); i++) {
if (!reloc_base[i].r_extern)
continue;
if (reloc_base[i].r_symbolnum > nsyms) {
warnx("%s: bad symbol number in text relocation", fn);
goto end;
}
used[reloc_base[i].r_symbolnum] = 1;
}
/* data */
reloc_base = (struct relocation_info *) ((char *)ep + N_DRELOFF(*ep));
if (N_DRELOFF(*ep) + ep->a_drsize > sp->st_size) {
warnx("%s: bad data relocation", fn);
goto end;
}
for (i = 0; i < ep->a_drsize / sizeof(struct relocation_info); i++) {
if (!reloc_base[i].r_extern)
continue;
if (reloc_base[i].r_symbolnum > nsyms) {
warnx("%s: bad symbol number in data relocation", fn);
goto end;
}
used[reloc_base[i].r_symbolnum] = 1;
}
/*
* Read through the symbol table. For each non-debugging symbol,
* copy it and save its string in the new string table. Keep
* track of the number of symbols.
*/
for (cnt = nsyms, i = 0, j = 0; cnt--; ++sym, ++i) {
fix_nlist_order(sym, mid);
if (!(sym->n_type & N_STAB) && sym->strx) {
*nsym = *sym;
nsym->strx = nstr - nstrbase;
p = strbase + sym->strx;
if (xflag && !used[i] &&
(!(sym->n_type & N_EXT) ||
(sym->n_type & ~N_EXT) == N_FN ||
strcmp(p, "gcc_compiled.") == 0 ||
strcmp(p, "gcc2_compiled.") == 0 ||
strncmp(p, "___gnu_compiled_", 16) == 0)) {
continue;
}
len = strlen(p) + 1;
mapping[i] = j++;
if (N_STROFF(*ep) + sym->strx + len > sp->st_size) {
warnx("%s: bad symbol table", fn);
goto end;
}
bcopy(p, nstr, len);
nstr += len;
fix_nlist_order(nsym++, mid);
}
}
/* renumber symbol relocations */
/* text */
reloc_base = (struct relocation_info *) ((char *)ep + N_TRELOFF(*ep));
for (i = 0; i < ep->a_trsize / sizeof(struct relocation_info); i++) {
if (!reloc_base[i].r_extern)
continue;
reloc_base[i].r_symbolnum = mapping[reloc_base[i].r_symbolnum];
}
/* data */
reloc_base = (struct relocation_info *) ((char *)ep + N_DRELOFF(*ep));
for (i = 0; i < ep->a_drsize / sizeof(struct relocation_info); i++) {
if (!reloc_base[i].r_extern)
continue;
reloc_base[i].r_symbolnum = mapping[reloc_base[i].r_symbolnum];
}
/* Fill in new symbol table size. */
ep->a_syms = (nsym - symbase) * sizeof(NLIST);
/* Fill in the new size of the string table. */
len = nstr - nstrbase;
*(u_long *)nstrbase = fix_32_order(len, mid);
/*
* Copy the new string table into place. Nsym should be pointing
* at the address past the last symbol entry.
*/
bcopy(nstrbase, (void *)nsym, len);
error = 0;
end:
free(nstrbase);
free(used);
free(mapping);
/* Truncate to the current length. */
*sz = (char *)nsym + len - (char *)ep;
return error;
}
void
usage(void)
{
extern char *__progname;
fprintf(stderr, "usage: %s [-dx] file ...\n", __progname);
exit(1);
}