binutils-gdb/bfd/lynx-core.c

/* BFD back end for Lynx core files
   Copyright (C) 1993-2018 Free Software Foundation, Inc.
   Written by Stu Grossman of Cygnus Support.

   This file is part of BFD, the Binary File Descriptor library.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"

#ifdef LYNX_CORE

#include <sys/conf.h>
#include <sys/kernel.h>
/* sys/kernel.h should define this, but doesn't always, sigh.  */
#ifndef __LYNXOS
#define __LYNXOS
#endif
#include <sys/mem.h>
#include <sys/signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/itimer.h>
#include <sys/file.h>
#include <sys/proc.h>

/* These are stored in the bfd's tdata */

struct lynx_core_struct
{
  int sig;
  char cmd[PNMLEN + 1];
};

#define core_hdr(bfd) ((bfd)->tdata.lynx_core_data)
#define core_signal(bfd) (core_hdr(bfd)->sig)
#define core_command(bfd) (core_hdr(bfd)->cmd)

#define lynx_core_file_matches_executable_p generic_core_file_matches_executable_p
#define lynx_core_file_pid _bfd_nocore_core_file_pid

/* Handle Lynx core dump file.  */

static asection *
make_bfd_asection (bfd *abfd,
		   const char *name,
		   flagword flags,
		   bfd_size_type size,
		   bfd_vma vma,
		   file_ptr filepos)
{
  asection *asect;
  char *newname;

  newname = bfd_alloc (abfd, (bfd_size_type) strlen (name) + 1);
  if (!newname)
    return NULL;

  strcpy (newname, name);

  asect = bfd_make_section_with_flags (abfd, newname, flags);
  if (!asect)
    return NULL;

  asect->size = size;
  asect->vma = vma;
  asect->filepos = filepos;
  asect->alignment_power = 2;

  return asect;
}

const bfd_target *
lynx_core_file_p (bfd *abfd)
{
  int secnum;
  struct pssentry pss;
  bfd_size_type tcontext_size;
  core_st_t *threadp;
  int pagesize;
  asection *newsect;
  bfd_size_type amt;

  pagesize = getpagesize ();	/* Serious cross-target issue here...  This
				   really needs to come from a system-specific
				   header file.  */

  /* Get the pss entry from the core file */

  if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
    return NULL;

  amt = sizeof pss;
  if (bfd_bread ((void *) &pss, amt, abfd) != amt)
    {
      /* Too small to be a core file */
      if (bfd_get_error () != bfd_error_system_call)
	bfd_set_error (bfd_error_wrong_format);
      return NULL;
    }

  amt = sizeof (struct lynx_core_struct);
  core_hdr (abfd) = (struct lynx_core_struct *) bfd_zalloc (abfd, amt);

  if (!core_hdr (abfd))
    return NULL;

  strncpy (core_command (abfd), pss.pname, PNMLEN + 1);

  /* Compute the size of the thread contexts */

  tcontext_size = pss.threadcnt * sizeof (core_st_t);

  /* Allocate space for the thread contexts */

  threadp = (core_st_t *) bfd_alloc (abfd, tcontext_size);
  if (!threadp)
    goto fail;

  /* Save thread contexts */

  if (bfd_seek (abfd, (file_ptr) pagesize, SEEK_SET) != 0)
    goto fail;

  if (bfd_bread ((void *) threadp, tcontext_size, abfd) != tcontext_size)
    {
      /* Probably too small to be a core file */
      if (bfd_get_error () != bfd_error_system_call)
	bfd_set_error (bfd_error_wrong_format);
      goto fail;
    }

  core_signal (abfd) = threadp->currsig;

  newsect = make_bfd_asection (abfd, ".stack",
			       SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS,
			       pss.ssize,
			       pss.slimit,
			       pagesize + tcontext_size);
  if (!newsect)
    goto fail;

  newsect = make_bfd_asection (abfd, ".data",
			       SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS,
			       pss.data_len + pss.bss_len,
			       pss.data_start,
			       pagesize + tcontext_size + pss.ssize
#if defined (SPARC) || defined (__SPARC__)
			       /* SPARC Lynx seems to start dumping
				  the .data section at a page
				  boundary.  It's OK to check a
				  #define like SPARC here because this
				  file can only be compiled on a Lynx
				  host.  */
			       + pss.data_start % pagesize
#endif
			       );
  if (!newsect)
    goto fail;

/* And, now for the .reg/XXX pseudo sections.  Each thread has it's own
   .reg/XXX section, where XXX is the thread id (without leading zeros).  The
   currently running thread (at the time of the core dump) also has an alias
   called `.reg' (just to keep GDB happy).  Note that we use `.reg/XXX' as
   opposed to `.regXXX' because GDB expects that .reg2 will be the floating-
   point registers.  */

  newsect = make_bfd_asection (abfd, ".reg",
			       SEC_HAS_CONTENTS,
			       sizeof (core_st_t),
			       0,
			       pagesize);
  if (!newsect)
    goto fail;

  for (secnum = 0; secnum < pss.threadcnt; secnum++)
    {
      char secname[100];

      sprintf (secname, ".reg/%d", BUILDPID (0, threadp[secnum].tid));
      newsect = make_bfd_asection (abfd, secname,
				   SEC_HAS_CONTENTS,
				   sizeof (core_st_t),
				   0,
				   pagesize + secnum * sizeof (core_st_t));
      if (!newsect)
	goto fail;
    }

  return abfd->xvec;

 fail:
  bfd_release (abfd, core_hdr (abfd));
  core_hdr (abfd) = NULL;
  bfd_section_list_clear (abfd);
  return NULL;
}

char *
lynx_core_file_failing_command (bfd *abfd)
{
  return core_command (abfd);
}

int
lynx_core_file_failing_signal (bfd *abfd)
{
  return core_signal (abfd);
}

#endif /* LYNX_CORE */