1 /* BFD back end for traditional Unix core files (U-area and raw sections)
2 Copyright (C) 1988-2023 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
41 struct 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
62 static bfd_cleanup
63 trad_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
220 static char *
221 trad_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
232 static int
233 trad_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. */
243 static void
244 swap_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
256 const 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 };