1/* BFD back end for traditional Unix core files (U-area and raw sections)
2   Copyright (C) 1988-2022 Free Software Foundation, Inc.
3   Written by John Gilmore of Cygnus Support.
4
5   This file is part of BFD, the Binary File Descriptor library.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20   MA 02110-1301, USA.  */
21
22#include "sysdep.h"
23#include "bfd.h"
24#include "libbfd.h"
25#include "libaout.h"	       /* BFD a.out internal data structures */
26
27#include <sys/param.h>
28#include <dirent.h>
29#include <signal.h>
30
31#include <sys/user.h>		/* After a.out.h  */
32
33#ifdef TRAD_HEADER
34#include TRAD_HEADER
35#endif
36
37#ifndef NBPG
38# define NBPG getpagesize()
39#endif
40
41struct trad_core_struct
42{
43  asection *data_section;
44  asection *stack_section;
45  asection *reg_section;
46  struct user u;
47};
48
49#define core_upage(bfd)  (&((bfd)->tdata.trad_core_data->u))
50#define core_datasec(bfd)  ((bfd)->tdata.trad_core_data->data_section)
51#define core_stacksec(bfd) ((bfd)->tdata.trad_core_data->stack_section)
52#define core_regsec(bfd)   ((bfd)->tdata.trad_core_data->reg_section)
53
54/* forward declarations */
55
56#define trad_unix_core_file_matches_executable_p generic_core_file_matches_executable_p
57#define trad_unix_core_file_pid _bfd_nocore_core_file_pid
58
59
60/* Handle 4.2-style (and perhaps also sysV-style) core dump file.  */
61
62static bfd_cleanup
63trad_unix_core_file_p (bfd *abfd)
64{
65  int val;
66  struct user u;
67  struct trad_core_struct *rawptr;
68  size_t amt;
69  flagword flags;
70
71#ifdef TRAD_CORE_USER_OFFSET
72  /* If defined, this macro is the file position of the user struct.  */
73  if (bfd_seek (abfd, (file_ptr) TRAD_CORE_USER_OFFSET, SEEK_SET) != 0)
74    return 0;
75#endif
76
77  val = bfd_bread ((void *) &u, (bfd_size_type) sizeof u, abfd);
78  if (val != sizeof u)
79    {
80      /* Too small to be a core file */
81      bfd_set_error (bfd_error_wrong_format);
82      return 0;
83    }
84
85  /* Sanity check perhaps??? */
86  if (u.u_dsize > 0x1000000)	/* Remember, it's in pages...  */
87    {
88      bfd_set_error (bfd_error_wrong_format);
89      return 0;
90    }
91  if (u.u_ssize > 0x1000000)
92    {
93      bfd_set_error (bfd_error_wrong_format);
94      return 0;
95    }
96
97  /* Check that the size claimed is no greater than the file size.  */
98  {
99    struct stat statbuf;
100
101    if (bfd_stat (abfd, &statbuf) < 0)
102      return 0;
103
104    if ((ufile_ptr) NBPG * (UPAGES + u.u_dsize
105#ifdef TRAD_CORE_DSIZE_INCLUDES_TSIZE
106			    - u.u_tsize
107#endif
108			    + u.u_ssize)
109	> (ufile_ptr) statbuf.st_size)
110      {
111	bfd_set_error (bfd_error_wrong_format);
112	return 0;
113      }
114#ifndef TRAD_CORE_ALLOW_ANY_EXTRA_SIZE
115    if (((ufile_ptr) NBPG * (UPAGES + u.u_dsize + u.u_ssize)
116#ifdef TRAD_CORE_EXTRA_SIZE_ALLOWED
117	/* Some systems write the file too big.  */
118	 + TRAD_CORE_EXTRA_SIZE_ALLOWED
119#endif
120	 )
121	< (ufile_ptr) statbuf.st_size)
122      {
123	/* The file is too big.  Maybe it's not a core file
124	   or we otherwise have bad values for u_dsize and u_ssize).  */
125	bfd_set_error (bfd_error_wrong_format);
126	return 0;
127      }
128#endif
129  }
130
131  /* OK, we believe you.  You're a core file (sure, sure).  */
132
133  /* Allocate both the upage and the struct core_data at once, so
134     a single free() will free them both.  */
135  amt = sizeof (struct trad_core_struct);
136  rawptr = (struct trad_core_struct *) bfd_zmalloc (amt);
137  if (rawptr == NULL)
138    return 0;
139
140  abfd->tdata.trad_core_data = rawptr;
141
142  rawptr->u = u; /*Copy the uarea into the tdata part of the bfd */
143
144  /* Create the sections.  */
145
146  flags = SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS;
147  core_stacksec(abfd) = bfd_make_section_anyway_with_flags (abfd, ".stack",
148							    flags);
149  if (core_stacksec (abfd) == NULL)
150    goto fail;
151  core_datasec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".data",
152							    flags);
153  if (core_datasec (abfd) == NULL)
154    goto fail;
155  core_regsec (abfd) = bfd_make_section_anyway_with_flags (abfd, ".reg",
156							   SEC_HAS_CONTENTS);
157  if (core_regsec (abfd) == NULL)
158    goto fail;
159
160  core_datasec (abfd)->size =  NBPG * u.u_dsize
161#ifdef TRAD_CORE_DSIZE_INCLUDES_TSIZE
162    - NBPG * u.u_tsize
163#endif
164      ;
165  core_stacksec (abfd)->size = NBPG * u.u_ssize;
166  core_regsec (abfd)->size = NBPG * UPAGES; /* Larger than sizeof struct u */
167
168  /* What a hack... we'd like to steal it from the exec file,
169     since the upage does not seem to provide it.  FIXME.  */
170#ifdef HOST_DATA_START_ADDR
171  core_datasec (abfd)->vma = HOST_DATA_START_ADDR;
172#else
173  core_datasec (abfd)->vma = HOST_TEXT_START_ADDR + (NBPG * u.u_tsize);
174#endif
175
176#ifdef HOST_STACK_START_ADDR
177  core_stacksec (abfd)->vma = HOST_STACK_START_ADDR;
178#else
179  core_stacksec (abfd)->vma = HOST_STACK_END_ADDR - (NBPG * u.u_ssize);
180#endif
181
182  /* This is tricky.  As the "register section", we give them the entire
183     upage and stack.  u.u_ar0 points to where "register 0" is stored.
184     There are two tricks with this, though.  One is that the rest of the
185     registers might be at positive or negative (or both) displacements
186     from *u_ar0.  The other is that u_ar0 is sometimes an absolute address
187     in kernel memory, and on other systems it is an offset from the beginning
188     of the `struct user'.
189
190     As a practical matter, we don't know where the registers actually are,
191     so we have to pass the whole area to GDB.  We encode the value of u_ar0
192     by setting the .regs section up so that its virtual memory address
193     0 is at the place pointed to by u_ar0 (by setting the vma of the start
194     of the section to -u_ar0).  GDB uses this info to locate the regs,
195     using minor trickery to get around the offset-or-absolute-addr problem.  */
196  core_regsec (abfd)->vma = - (bfd_vma) (unsigned long) u.u_ar0;
197
198  core_datasec (abfd)->filepos = NBPG * UPAGES;
199  core_stacksec (abfd)->filepos = (NBPG * UPAGES) + NBPG * u.u_dsize
200#ifdef TRAD_CORE_DSIZE_INCLUDES_TSIZE
201    - NBPG * u.u_tsize
202#endif
203      ;
204  core_regsec (abfd)->filepos = 0; /* Register segment is the upage */
205
206  /* Align to word at least */
207  core_stacksec (abfd)->alignment_power = 2;
208  core_datasec (abfd)->alignment_power = 2;
209  core_regsec (abfd)->alignment_power = 2;
210
211  return _bfd_no_cleanup;
212
213 fail:
214  bfd_release (abfd, abfd->tdata.any);
215  abfd->tdata.any = NULL;
216  bfd_section_list_clear (abfd);
217  return NULL;
218}
219
220static char *
221trad_unix_core_file_failing_command (bfd *abfd)
222{
223#ifndef NO_CORE_COMMAND
224  char *com = abfd->tdata.trad_core_data->u.u_comm;
225  if (*com)
226    return com;
227  else
228#endif
229    return 0;
230}
231
232static int
233trad_unix_core_file_failing_signal (bfd *ignore_abfd ATTRIBUTE_UNUSED)
234{
235#ifdef TRAD_UNIX_CORE_FILE_FAILING_SIGNAL
236  return TRAD_UNIX_CORE_FILE_FAILING_SIGNAL(ignore_abfd);
237#else
238  return -1;		/* FIXME, where is it? */
239#endif
240}
241
242/* If somebody calls any byte-swapping routines, shoot them.  */
243static void
244swap_abort (void)
245{
246  abort (); /* This way doesn't require any declaration for ANSI to fuck up */
247}
248
249#define	NO_GET ((bfd_vma (*) (const void *)) swap_abort)
250#define	NO_PUT ((void (*) (bfd_vma, void *)) swap_abort)
251#define	NO_GETS ((bfd_signed_vma (*) (const void *)) swap_abort)
252#define	NO_GET64 ((uint64_t (*) (const void *)) swap_abort)
253#define	NO_PUT64 ((void (*) (uint64_t, void *)) swap_abort)
254#define	NO_GETS64 ((int64_t (*) (const void *)) swap_abort)
255
256const bfd_target core_trad_vec =
257  {
258    "trad-core",
259    bfd_target_unknown_flavour,
260    BFD_ENDIAN_UNKNOWN,		/* target byte order */
261    BFD_ENDIAN_UNKNOWN,		/* target headers byte order */
262    (HAS_RELOC | EXEC_P |	/* object flags */
263     HAS_LINENO | HAS_DEBUG |
264     HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
265    (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
266    0,				/* symbol prefix */
267    ' ',			/* ar_pad_char */
268    16,				/* ar_max_namelen */
269    0,				/* match priority.  */
270    TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols.  */
271    NO_GET64, NO_GETS64, NO_PUT64,	/* 64 bit data */
272    NO_GET, NO_GETS, NO_PUT,		/* 32 bit data */
273    NO_GET, NO_GETS, NO_PUT,		/* 16 bit data */
274    NO_GET64, NO_GETS64, NO_PUT64,	/* 64 bit hdrs */
275    NO_GET, NO_GETS, NO_PUT,		/* 32 bit hdrs */
276    NO_GET, NO_GETS, NO_PUT,		/* 16 bit hdrs */
277
278    {				/* bfd_check_format */
279      _bfd_dummy_target,		/* unknown format */
280      _bfd_dummy_target,		/* object file */
281      _bfd_dummy_target,		/* archive */
282      trad_unix_core_file_p		/* a core file */
283    },
284    {				/* bfd_set_format */
285      _bfd_bool_bfd_false_error,
286      _bfd_bool_bfd_false_error,
287      _bfd_bool_bfd_false_error,
288      _bfd_bool_bfd_false_error
289    },
290    {				/* bfd_write_contents */
291      _bfd_bool_bfd_false_error,
292      _bfd_bool_bfd_false_error,
293      _bfd_bool_bfd_false_error,
294      _bfd_bool_bfd_false_error
295    },
296
297    BFD_JUMP_TABLE_GENERIC (_bfd_generic),
298    BFD_JUMP_TABLE_COPY (_bfd_generic),
299    BFD_JUMP_TABLE_CORE (trad_unix),
300    BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
301    BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
302    BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
303    BFD_JUMP_TABLE_WRITE (_bfd_generic),
304    BFD_JUMP_TABLE_LINK (_bfd_nolink),
305    BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
306
307    NULL,
308
309    NULL			/* backend_data */
310  };
311