Пример #1
0
/* Set parameters about this a.out file that are machine-dependent.
   This routine is called from some_aout_object_p just before it returns.  */
static const bfd_target *
MY (callback) (bfd *abfd)
{
  struct internal_exec *execp = exec_hdr (abfd);

  /* Calculate the file positions of the parts of a newly read aout header */
  obj_textsec (abfd)->size = N_TXTSIZE (*execp);

  /* The virtual memory addresses of the sections */
  obj_textsec (abfd)->vma = N_TXTADDR (*execp);
  obj_datasec (abfd)->vma = N_DATADDR (*execp);
  obj_bsssec (abfd)->vma = N_BSSADDR (*execp);

  obj_textsec (abfd)->lma = obj_textsec (abfd)->vma;
  obj_datasec (abfd)->lma = obj_datasec (abfd)->vma;
  obj_bsssec (abfd)->lma = obj_bsssec (abfd)->vma;

  /* The file offsets of the sections */
  obj_textsec (abfd)->filepos = N_TXTOFF (*execp);
  obj_datasec (abfd)->filepos = N_DATOFF (*execp);

  /* The file offsets of the relocation info */
  obj_textsec (abfd)->rel_filepos = N_TRELOFF (*execp);
  obj_datasec (abfd)->rel_filepos = N_DRELOFF (*execp);

  /* The file offsets of the string table and symbol table.  */
  obj_sym_filepos (abfd) = N_SYMOFF (*execp);
  obj_str_filepos (abfd) = N_STROFF (*execp);

  /* Determine the architecture and machine type of the object file.  */
#ifdef SET_ARCH_MACH
  SET_ARCH_MACH (abfd, *execp);
#else
  bfd_default_set_arch_mach (abfd, DEFAULT_ARCH, 0);
#endif

  if (obj_aout_subformat (abfd) == gnu_encap_format)
    {
      /* The file offsets of the relocation info */
      obj_textsec (abfd)->rel_filepos = N_GNU_TRELOFF (*execp);
      obj_datasec (abfd)->rel_filepos = N_GNU_DRELOFF (*execp);

      /* The file offsets of the string table and symbol table.  */
      obj_sym_filepos (abfd) = N_GNU_SYMOFF (*execp);
      obj_str_filepos (abfd) = (obj_sym_filepos (abfd) + execp->a_syms);

      abfd->flags |= HAS_LINENO | HAS_DEBUG | HAS_SYMS | HAS_LOCALS;
      bfd_get_symcount (abfd) = execp->a_syms / 12;
      obj_symbol_entry_size (abfd) = 12;
      obj_reloc_entry_size (abfd) = RELOC_STD_SIZE;
    }

  return abfd->xvec;
}
Пример #2
0
static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
	struct exec ex;
	unsigned long error;
	unsigned long fd_offset;
	unsigned long rlim;
	unsigned long orig_thr_flags;
	int retval;

	ex = *((struct exec *) bprm->buf);		/* exec-header */
	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
	     N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
	    N_TRSIZE(ex) || N_DRSIZE(ex) ||
	    bprm->file->f_path.dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
		return -ENOEXEC;
	}

	fd_offset = N_TXTOFF(ex);

	/* Check initial limits. This avoids letting people circumvent
	 * size limits imposed on them by creating programs with large
	 * arrays in the data or bss.
	 */
	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
	if (rlim >= RLIM_INFINITY)
		rlim = ~0;
	if (ex.a_data + ex.a_bss > rlim)
		return -ENOMEM;

	/* Flush all traces of the currently running executable */
	retval = flush_old_exec(bprm);
	if (retval)
		return retval;

	/* OK, This is the point of no return */
	set_personality(PER_SUNOS);

	current->mm->end_code = ex.a_text +
		(current->mm->start_code = N_TXTADDR(ex));
	current->mm->end_data = ex.a_data +
		(current->mm->start_data = N_DATADDR(ex));
	current->mm->brk = ex.a_bss +
		(current->mm->start_brk = N_BSSADDR(ex));
	current->mm->free_area_cache = current->mm->mmap_base;
	current->mm->cached_hole_size = 0;

	current->mm->mmap = NULL;
	compute_creds(bprm);
 	current->flags &= ~PF_FORKNOEXEC;
	if (N_MAGIC(ex) == NMAGIC) {
		loff_t pos = fd_offset;
		/* F**k me plenty... */
		down_write(&current->mm->mmap_sem);	
		error = do_brk(N_TXTADDR(ex), ex.a_text);
		up_write(&current->mm->mmap_sem);
		bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
			  ex.a_text, &pos);
		down_write(&current->mm->mmap_sem);
		error = do_brk(N_DATADDR(ex), ex.a_data);
		up_write(&current->mm->mmap_sem);
		bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex),
			  ex.a_data, &pos);
		goto beyond_if;
	}

	if (N_MAGIC(ex) == OMAGIC) {
		loff_t pos = fd_offset;
		down_write(&current->mm->mmap_sem);
		do_brk(N_TXTADDR(ex) & PAGE_MASK,
			ex.a_text+ex.a_data + PAGE_SIZE - 1);
		up_write(&current->mm->mmap_sem);
		bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
			  ex.a_text+ex.a_data, &pos);
	} else {
		static unsigned long error_time;
		if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
		    (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ)
		{
			printk(KERN_NOTICE "executable not page aligned\n");
			error_time = jiffies;
		}

		if (!bprm->file->f_op->mmap) {
			loff_t pos = fd_offset;
			down_write(&current->mm->mmap_sem);
			do_brk(0, ex.a_text+ex.a_data);
			up_write(&current->mm->mmap_sem);
			bprm->file->f_op->read(bprm->file,
				  (char __user *)N_TXTADDR(ex),
				  ex.a_text+ex.a_data, &pos);
			goto beyond_if;
		}

	        down_write(&current->mm->mmap_sem);
		error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
			PROT_READ | PROT_EXEC,
			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
			fd_offset);
	        up_write(&current->mm->mmap_sem);

		if (error != N_TXTADDR(ex)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}

	        down_write(&current->mm->mmap_sem);
 		error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
				PROT_READ | PROT_WRITE | PROT_EXEC,
				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
				fd_offset + ex.a_text);
	        up_write(&current->mm->mmap_sem);
		if (error != N_DATADDR(ex)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}
	}
beyond_if:
	set_binfmt(&aout32_format);

	set_brk(current->mm->start_brk, current->mm->brk);

	/* Make sure STACK_TOP returns the right thing.  */
	orig_thr_flags = current_thread_info()->flags;
	current_thread_info()->flags |= _TIF_32BIT;

	retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
	if (retval < 0) { 
		current_thread_info()->flags = orig_thr_flags;

		/* Someone check-me: is this error path enough? */ 
		send_sig(SIGKILL, current, 0); 
		return retval;
	}

	current->mm->start_stack =
		(unsigned long) create_aout32_tables((char __user *)bprm->p, bprm);
	tsb_context_switch(current->mm);

	start_thread32(regs, ex.a_entry, current->mm->start_stack);
	if (current->ptrace & PT_PTRACED)
		send_sig(SIGTRAP, current, 0);
	return 0;
}
Пример #3
0
static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
	struct exec ex;
	unsigned long error;
	unsigned long fd_offset;
	unsigned long rlim;
	int retval;

	ex = *((struct exec *) bprm->buf);		/* exec-header */
	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
	     N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
	    N_TRSIZE(ex) || N_DRSIZE(ex) ||
	    bprm->file->f_dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
		return -ENOEXEC;
	}

	fd_offset = N_TXTOFF(ex);

	/* Check initial limits. This avoids letting people circumvent
	 * size limits imposed on them by creating programs with large
	 * arrays in the data or bss.
	 */
	rlim = current->rlim[RLIMIT_DATA].rlim_cur;
	if (rlim >= RLIM_INFINITY)
		rlim = ~0;
	if (ex.a_data + ex.a_bss > rlim)
		return -ENOMEM;

	/* Flush all traces of the currently running executable */
	retval = flush_old_exec(bprm);
	if (retval)
		return retval;

	/* OK, This is the point of no return */
#if defined(__alpha__)
	SET_AOUT_PERSONALITY(bprm, ex);
#elif defined(__sparc__)
	set_personality(PER_SUNOS);
#if !defined(__sparc_v9__)
	memcpy(&current->thread.core_exec, &ex, sizeof(struct exec));
#endif
#else
	set_personality(PER_LINUX);
#endif

	current->mm->end_code = ex.a_text +
		(current->mm->start_code = N_TXTADDR(ex));
	current->mm->end_data = ex.a_data +
		(current->mm->start_data = N_DATADDR(ex));
	current->mm->brk = ex.a_bss +
		(current->mm->start_brk = N_BSSADDR(ex));

	current->mm->rss = 0;
	current->mm->mmap = NULL;

#ifdef CONFIG_ARM_FASS
	arch_new_mm(current, current->mm);
#endif

	compute_creds(bprm);
 	current->flags &= ~PF_FORKNOEXEC;
#ifdef __sparc__
	if (N_MAGIC(ex) == NMAGIC) {
		loff_t pos = fd_offset;
		/* F**k me plenty... */
		/* <AOL></AOL> */
		error = do_brk(N_TXTADDR(ex), ex.a_text);
		bprm->file->f_op->read(bprm->file, (char *) N_TXTADDR(ex),
			  ex.a_text, &pos);
		error = do_brk(N_DATADDR(ex), ex.a_data);
		bprm->file->f_op->read(bprm->file, (char *) N_DATADDR(ex),
			  ex.a_data, &pos);
		goto beyond_if;
	}
#endif

	if (N_MAGIC(ex) == OMAGIC) {
		unsigned long text_addr, map_size;
		loff_t pos;

		text_addr = N_TXTADDR(ex);

#if defined(__alpha__) || defined(__sparc__)
		pos = fd_offset;
		map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
#else
		pos = 32;
		map_size = ex.a_text+ex.a_data;
#endif

		error = do_brk(text_addr & PAGE_MASK, map_size);
		if (error != (text_addr & PAGE_MASK)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}

		error = bprm->file->f_op->read(bprm->file, (char *)text_addr,
			  ex.a_text+ex.a_data, &pos);
		if ((signed long)error < 0) {
			send_sig(SIGKILL, current, 0);
			return error;
		}
			 
		flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
	} else {
		static unsigned long error_time, error_time2;
		if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
		    (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time2) > 5*HZ)
		{
			printk(KERN_NOTICE "executable not page aligned\n");
			error_time2 = jiffies;
		}

		if ((fd_offset & ~PAGE_MASK) != 0 &&
		    (jiffies-error_time) > 5*HZ)
		{
			printk(KERN_WARNING 
			       "fd_offset is not page aligned. Please convert program: %s\n",
			       bprm->file->f_dentry->d_name.name);
			error_time = jiffies;
		}

		if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
			loff_t pos = fd_offset;
			do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
			bprm->file->f_op->read(bprm->file,(char *)N_TXTADDR(ex),
					ex.a_text+ex.a_data, &pos);
			flush_icache_range((unsigned long) N_TXTADDR(ex),
					   (unsigned long) N_TXTADDR(ex) +
					   ex.a_text+ex.a_data);
			goto beyond_if;
		}

		down_write(&current->mm->mmap_sem);
		error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
			PROT_READ | PROT_EXEC,
			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
			fd_offset);
		up_write(&current->mm->mmap_sem);

		if (error != N_TXTADDR(ex)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}

		down_write(&current->mm->mmap_sem);
 		error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
				PROT_READ | PROT_WRITE | PROT_EXEC,
				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
				fd_offset + ex.a_text);
		up_write(&current->mm->mmap_sem);
		if (error != N_DATADDR(ex)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}
	}
beyond_if:
	set_binfmt(&aout_format);

	set_brk(current->mm->start_brk, current->mm->brk);

	retval = setup_arg_pages(bprm); 
	if (retval < 0) { 
		/* Someone check-me: is this error path enough? */ 
		send_sig(SIGKILL, current, 0); 
		return retval;
	}

	current->mm->start_stack =
		(unsigned long) create_aout_tables((char *) bprm->p, bprm);
#ifdef __alpha__
	regs->gp = ex.a_gpvalue;
#endif
	start_thread(regs, ex.a_entry, current->mm->start_stack);
	if (current->ptrace & PT_PTRACED)
		send_sig(SIGTRAP, current, 0);
#ifndef __arm__
	return 0;
#else
	return regs->ARM_r0;
#endif
}
Пример #4
0
static inline int
do_load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
	struct exec ex;
	struct file * file;
	int fd;
	unsigned long error;
	unsigned long p = bprm->p;
	unsigned long fd_offset;
	unsigned long rlim;

	ex = *((struct exec *) bprm->buf);		/* exec-header */
	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && 
	     N_MAGIC(ex) != QMAGIC) ||
	    N_TRSIZE(ex) || N_DRSIZE(ex) ||
	    bprm->inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
		return -ENOEXEC;
	}

	current->personality = PER_LINUX;
	fd_offset = N_TXTOFF(ex);

#if defined (__i386__) || defined (CONFIG_ARM)
	if (N_MAGIC(ex) == ZMAGIC && fd_offset != BLOCK_SIZE) {
		printk(KERN_NOTICE "N_TXTOFF != BLOCK_SIZE. See a.out.h.\n");
		return -ENOEXEC;
	}

	if (N_MAGIC(ex) == ZMAGIC && ex.a_text &&
	    (fd_offset < bprm->inode->i_sb->s_blocksize)) {
		printk(KERN_NOTICE "N_TXTOFF < BLOCK_SIZE. Please convert binary.\n");
		return -ENOEXEC;
	}
#endif
#if defined(CONFIG_ARM)
	if (N_MACHTYPE(ex) != M_ARM) {
		printk(KERN_NOTICE "Binary != ARM.  Please recompile binary.\n");
		return -ENOEXEC;
	}
#endif

	/* Check initial limits. This avoids letting people circumvent
	 * size limits imposed on them by creating programs with large
	 * arrays in the data or bss.
	 */
	rlim = current->rlim[RLIMIT_DATA].rlim_cur;
	if (rlim >= RLIM_INFINITY)
		rlim = ~0;
	if (ex.a_data + ex.a_bss > rlim)
		return -ENOMEM;

	if (flush_old_exec(bprm))
		return -ENOMEM;

	/* OK, This is the point of no return */

	current->mm->end_code = ex.a_text +
		(current->mm->start_code = N_TXTADDR(ex));
	current->mm->end_data = ex.a_data +
		(current->mm->start_data = N_DATADDR(ex));
	current->mm->brk = ex.a_bss +
		(current->mm->start_brk = N_BSSADDR(ex));

	current->mm->rss = 0;
	current->mm->mmap = NULL;
	current->suid = current->euid = current->fsuid = bprm->e_uid;
	current->sgid = current->egid = current->fsgid = bprm->e_gid;
 	current->flags &= ~PF_FORKNOEXEC;
	if (N_MAGIC(ex) == OMAGIC) {
#if defined(__alpha__) || defined(CONFIG_ARM)
#ifndef CONFIG_ARM
		do_mmap(NULL, N_TXTADDR(ex) & PAGE_MASK,
			ex.a_text+ex.a_data + PAGE_SIZE - 1,
			PROT_READ|PROT_WRITE|PROT_EXEC,
			MAP_FIXED|MAP_PRIVATE, 0);
#else
		do_mmap(NULL, N_TXTADDR(ex),
			ex.a_text+ex.a_data,
			PROT_READ|PROT_WRITE|PROT_EXEC,
			MAP_FIXED|MAP_PRIVATE, 0);
#endif
		read_exec(bprm->inode, fd_offset, (char *) N_TXTADDR(ex),
			  ex.a_text+ex.a_data, 0);
#else
		do_mmap(NULL, 0, ex.a_text+ex.a_data,
			PROT_READ|PROT_WRITE|PROT_EXEC,
			MAP_FIXED|MAP_PRIVATE, 0);
		read_exec(bprm->inode, 32, (char *) 0, ex.a_text+ex.a_data, 0);
#endif
	} else {
		if (ex.a_text & 0xfff || ex.a_data & 0xfff)
			printk(KERN_NOTICE "executable not page aligned\n");
		
		fd = open_inode(bprm->inode, O_RDONLY);
		
		if (fd < 0) {
			send_sig(SIGKILL, current, 0);
			return fd;
		}
		file = current->files->fd[fd];
		if (!file->f_op || !file->f_op->mmap) {
			sys_close(fd);
			do_mmap(NULL, 0, ex.a_text+ex.a_data,
				PROT_READ|PROT_WRITE|PROT_EXEC,
				MAP_FIXED|MAP_PRIVATE, 0);
			read_exec(bprm->inode, fd_offset,
				  (char *) N_TXTADDR(ex), ex.a_text+ex.a_data, 0);
			goto beyond_if;
		}

		error = do_mmap(file, N_TXTADDR(ex), ex.a_text,
			PROT_READ | PROT_EXEC,
			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
			fd_offset);

		if (error != N_TXTADDR(ex)) {
			sys_close(fd);
			send_sig(SIGKILL, current, 0);
			return error;
		}
		
 		error = do_mmap(file, N_DATADDR(ex), ex.a_data,
				PROT_READ | PROT_WRITE | PROT_EXEC,
				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
				fd_offset + ex.a_text);
		sys_close(fd);
		if (error != N_DATADDR(ex)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}
	}
beyond_if:
	if (current->exec_domain && current->exec_domain->use_count)
		(*current->exec_domain->use_count)--;
	if (current->binfmt && current->binfmt->use_count)
		(*current->binfmt->use_count)--;
	current->exec_domain = lookup_exec_domain(current->personality);
	current->binfmt = &aout_format;
	if (current->exec_domain && current->exec_domain->use_count)
		(*current->exec_domain->use_count)++;
	if (current->binfmt && current->binfmt->use_count)
		(*current->binfmt->use_count)++;

	set_brk(current->mm->start_brk, current->mm->brk);

	p = setup_arg_pages(p, bprm);
	
	p = (unsigned long) create_aout_tables((char *)p, bprm);
	current->mm->start_stack = p;
#ifdef __alpha__
	regs->gp = ex.a_gpvalue;
#endif
	start_thread(regs, ex.a_entry, p);
	if (current->flags & PF_PTRACED)
		send_sig(SIGTRAP, current, 0);
#ifndef CONFIG_ARM
	return 0;
#else
	return regs->ARM_r0;
#endif
}
Пример #5
0
int
main(int argc, char *argv[])
{
	struct exec head;
	struct ecoff_exechdr ehead;
	struct ecoff_scnhdr escn[3];
	int infd, outfd;
	int n;

	if (argc != 3)
		usage();

	infd = open(argv[1], O_RDONLY);
	if (infd < 0)
		err(1, argv[1]);

	outfd = open(argv[2], O_WRONLY | O_TRUNC | O_CREAT, 0644);
	if (outfd < 0)
		err(1, argv[2]);

	n = read(infd, &head, sizeof(head));
	if (n < sizeof(head))
		err(1, "read");

	if (N_BADMAG(head)) {
		printf("%s: bad magic number\n", argv[1]);
		exit(1);
	}

	if (head.a_trsize || head.a_drsize) {
		printf("%s: has relocations\n", argv[1]);
		exit(1);
	}

	/*
	 * Header
	 */

	ehead.f.f_magic = 0x016d;		/* MC88OMAGIC */
	ehead.f.f_nscns = 3;
	ehead.f.f_timdat = 0;			/* ignored */
	ehead.f.f_symptr = 0;			/* ignored */
	ehead.f.f_nsyms = 0;			/* ignored */
	ehead.f.f_opthdr = sizeof ehead.a;
	ehead.f.f_flags = 0x020f;
		/* F_RELFLG | F_EXEC | F_LNNO | 8 | F_AR16WR */

	ehead.a.magic = N_GETMAGIC(head);
	ehead.a.vstamp = 0;			/* ignored */
	ehead.a.tsize = head.a_text;		/* ignored */
	ehead.a.dsize = head.a_data;		/* ignored */
	ehead.a.bsize = head.a_bss;		/* ignored */
	ehead.a.entry = head.a_entry;
	ehead.a.text_start = N_TXTADDR(head);	/* ignored */
	ehead.a.data_start = N_DATADDR(head);	/* ignored */

	n = write(outfd, &ehead, sizeof(ehead));
	if (n != sizeof(ehead))
		err(1, "write");

	/*
	 * Sections.
	 * Note that we merge .bss into .data since the PROM will not
	 * clear it and locore does not do this either.
	 */

	strncpy(escn[0].s_name, ".text", sizeof escn[0].s_name);
	escn[0].s_paddr = N_TXTADDR(head);	/* ignored, 1:1 mapping */
	escn[0].s_size = round(head.a_text, 8);
	escn[0].s_scnptr = round(sizeof(ehead) + sizeof(escn), 0x10);
	escn[0].s_relptr = 0;
	escn[0].s_lnnoptr = 0;
	escn[0].s_nlnno = 0;
	escn[0].s_flags = 0x20;	/* STYP_TEXT */

	strncpy(escn[1].s_name, ".data", sizeof escn[1].s_name);
	escn[1].s_paddr = N_DATADDR(head);		/* ignored, 1:1 mapping */
	escn[1].s_scnptr = escn[0].s_scnptr + escn[0].s_size;
	escn[1].s_size = round(head.a_data + head.a_bss, 8);
	escn[1].s_relptr = 0;
	escn[1].s_lnnoptr = 0;
	escn[1].s_nlnno = 0;
	escn[1].s_flags = 0x40;	/* STYP_DATA */

	strncpy(escn[2].s_name, ".bss", sizeof escn[2].s_name);
	escn[2].s_paddr = N_BSSADDR(head) + head.a_bss;	/* ignored, 1:1 mapping */
	escn[2].s_scnptr = 0;		/* nothing in the file */
	escn[2].s_size = 0;
	escn[2].s_relptr = 0;
	escn[2].s_lnnoptr = 0;
	escn[2].s_nlnno = 0;
	escn[2].s_flags = 0x80;	/* STYP_BSS */

	/* adjust load addresses */
	escn[0].s_paddr += (head.a_entry & ~(__LDPGSZ - 1)) - __LDPGSZ;
	escn[1].s_paddr += (head.a_entry & ~(__LDPGSZ - 1)) - __LDPGSZ;
	escn[2].s_paddr += (head.a_entry & ~(__LDPGSZ - 1)) - __LDPGSZ;
	escn[0].s_vaddr = escn[0].s_paddr;
	escn[1].s_vaddr = escn[1].s_paddr;
	escn[2].s_vaddr = escn[2].s_paddr;

	n = write(outfd, &escn, sizeof(escn));
	if (n != sizeof(escn))
		err(1, "write");

	/*
	 * Copy text section
	 */

#ifdef DEBUG
	printf("copying %s: source %lx dest %lx size %x\n",
	    escn[0].s_name, N_TXTOFF(head), escn[0].s_scnptr, head.a_text);
#endif
	lseek(outfd, escn[0].s_scnptr, SEEK_SET);
	lseek(infd, N_TXTOFF(head), SEEK_SET);
	copybits(infd, outfd, head.a_text);

	/*
	 * Copy data section
	 */

#ifdef DEBUG
	printf("copying %s: source %lx dest %lx size %x\n",
	    escn[1].s_name, N_DATOFF(head), escn[1].s_scnptr, head.a_data);
#endif
	lseek(outfd, escn[1].s_scnptr, SEEK_SET);
	lseek(infd, N_DATOFF(head), SEEK_SET);
	copybits(infd, outfd, head.a_data);

	/*
	 * ``Copy'' bss section
	 */

#ifdef DEBUG
	printf("copying %s: size %lx\n",
	    escn[2].s_name, round(head.a_data + head.a_bss, 8) - head.a_data);
#endif
	zerobits(outfd, round(head.a_data + head.a_bss, 8) - head.a_data);

	close(infd);
	close(outfd);
	exit(0);
}