1 /* Definitions for BFD wrappers used by GDB.
3 Copyright (C) 2011, 2012
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "gdb_assert.h"
24 #include "gdb_string.h"
34 #define MAP_FAILED ((void *) -1)
38 /* An object of this type is stored in the section's user data when
41 struct gdb_bfd_section_data
43 /* Size of the data. */
45 /* If the data was mmapped, this is the length of the map. */
46 bfd_size_type map_len
;
47 /* The data. If NULL, the section data has not been read. */
49 /* If the data was mmapped, this is the map address. */
53 /* A hash table holding every BFD that gdb knows about. This is not
54 to be confused with 'gdb_bfd_cache', which is used for sharing
55 BFDs; in contrast, this hash is used just to implement
58 static htab_t all_bfds
;
63 gdb_bfd_stash_filename (struct bfd
*abfd
)
65 char *name
= bfd_get_filename (abfd
);
68 data
= bfd_alloc (abfd
, strlen (name
) + 1);
71 /* Unwarranted chumminess with BFD. */
72 abfd
->filename
= data
;
75 /* An object of this type is stored in each BFD's user data. */
79 /* The reference count. */
82 /* The mtime of the BFD at the point the cache entry was made. */
85 /* If the BFD comes from an archive, this points to the archive's
86 BFD. Otherwise, this is NULL. */
93 #define GDB_BFD_DATA_ACCESSOR(ABFD) \
94 ((struct gdb_bfd_data *) bfd_usrdata (ABFD))
96 DEFINE_REGISTRY (bfd
, GDB_BFD_DATA_ACCESSOR
)
98 /* A hash table storing all the BFDs maintained in the cache. */
100 static htab_t gdb_bfd_cache
;
102 /* The type of an object being looked up in gdb_bfd_cache. We use
103 htab's capability of storing one kind of object (BFD in this case)
104 and using a different sort of object for searching. */
106 struct gdb_bfd_cache_search
109 const char *filename
;
114 /* A hash function for BFDs. */
117 hash_bfd (const void *b
)
121 /* It is simplest to just hash the filename. */
122 return htab_hash_string (bfd_get_filename (abfd
));
125 /* An equality function for BFDs. Note that this expects the caller
126 to search using struct gdb_bfd_cache_search only, not BFDs. */
129 eq_bfd (const void *a
, const void *b
)
132 const struct gdb_bfd_cache_search
*s
= b
;
133 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
135 return (gdata
->mtime
== s
->mtime
136 && strcmp (bfd_get_filename (abfd
), s
->filename
) == 0);
142 gdb_bfd_open (const char *name
, const char *target
, int fd
)
147 struct gdb_bfd_cache_search search
;
150 if (gdb_bfd_cache
== NULL
)
151 gdb_bfd_cache
= htab_create_alloc (1, hash_bfd
, eq_bfd
, NULL
,
156 fd
= open (name
, O_RDONLY
| O_BINARY
);
159 bfd_set_error (bfd_error_system_call
);
164 search
.filename
= name
;
165 if (fstat (fd
, &st
) < 0)
167 /* Weird situation here. */
171 search
.mtime
= st
.st_mtime
;
173 /* Note that this must compute the same result as hash_bfd. */
174 hash
= htab_hash_string (name
);
175 /* Note that we cannot use htab_find_slot_with_hash here, because
176 opening the BFD may fail; and this would violate hashtab
178 abfd
= htab_find_with_hash (gdb_bfd_cache
, &search
, hash
);
186 abfd
= bfd_fopen (name
, target
, FOPEN_RB
, fd
);
190 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
, INSERT
);
194 gdb_bfd_stash_filename (abfd
);
199 /* A helper function that releases any section data attached to the
203 free_one_bfd_section (bfd
*abfd
, asection
*sectp
, void *ignore
)
205 struct gdb_bfd_section_data
*sect
= bfd_get_section_userdata (abfd
, sectp
);
207 if (sect
!= NULL
&& sect
->data
!= NULL
)
210 if (sect
->map_addr
!= NULL
)
214 res
= munmap (sect
->map_addr
, sect
->map_len
);
215 gdb_assert (res
== 0);
223 /* Close ABFD, and warn if that fails. */
226 gdb_bfd_close_or_warn (struct bfd
*abfd
)
229 char *name
= bfd_get_filename (abfd
);
231 bfd_map_over_sections (abfd
, free_one_bfd_section
, NULL
);
233 ret
= bfd_close (abfd
);
236 warning (_("cannot close \"%s\": %s"),
237 name
, bfd_errmsg (bfd_get_error ()));
245 gdb_bfd_ref (struct bfd
*abfd
)
247 struct gdb_bfd_data
*gdata
;
253 gdata
= bfd_usrdata (abfd
);
261 gdata
= bfd_zalloc (abfd
, sizeof (struct gdb_bfd_data
));
263 gdata
->mtime
= bfd_get_mtime (abfd
);
264 gdata
->archive_bfd
= NULL
;
265 bfd_usrdata (abfd
) = gdata
;
267 bfd_alloc_data (abfd
);
269 /* This is the first we've seen it, so add it to the hash table. */
270 slot
= htab_find_slot (all_bfds
, abfd
, INSERT
);
271 gdb_assert (slot
&& !*slot
);
278 gdb_bfd_unref (struct bfd
*abfd
)
280 struct gdb_bfd_data
*gdata
;
281 struct gdb_bfd_cache_search search
;
287 gdata
= bfd_usrdata (abfd
);
288 gdb_assert (gdata
->refc
>= 1);
294 archive_bfd
= gdata
->archive_bfd
;
295 search
.filename
= bfd_get_filename (abfd
);
297 if (gdb_bfd_cache
&& search
.filename
)
299 hashval_t hash
= htab_hash_string (search
.filename
);
302 search
.mtime
= gdata
->mtime
;
303 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
,
307 htab_clear_slot (gdb_bfd_cache
, slot
);
310 bfd_free_data (abfd
);
311 bfd_usrdata (abfd
) = NULL
; /* Paranoia. */
313 htab_remove_elt (all_bfds
, abfd
);
315 gdb_bfd_close_or_warn (abfd
);
317 gdb_bfd_unref (archive_bfd
);
320 /* A helper function that returns the section data descriptor
321 associated with SECTION. If no such descriptor exists, a new one
322 is allocated and cleared. */
324 static struct gdb_bfd_section_data
*
325 get_section_descriptor (asection
*section
)
327 struct gdb_bfd_section_data
*result
;
329 result
= bfd_get_section_userdata (section
->owner
, section
);
333 result
= bfd_zalloc (section
->owner
, sizeof (*result
));
334 bfd_set_section_userdata (section
->owner
, section
, result
);
340 /* Decompress a section that was compressed using zlib. Store the
341 decompressed buffer, and its size, in DESCRIPTOR. */
344 zlib_decompress_section (asection
*sectp
,
345 struct gdb_bfd_section_data
*descriptor
)
347 bfd
*abfd
= sectp
->owner
;
349 error (_("Support for zlib-compressed data (from '%s', section '%s') "
350 "is disabled in this copy of GDB"),
351 bfd_get_filename (abfd
),
352 bfd_get_section_name (abfd
, sectp
));
354 bfd_size_type compressed_size
= bfd_get_section_size (sectp
);
355 gdb_byte
*compressed_buffer
= xmalloc (compressed_size
);
356 struct cleanup
*cleanup
= make_cleanup (xfree
, compressed_buffer
);
357 struct cleanup
*inner_cleanup
;
358 bfd_size_type uncompressed_size
;
359 gdb_byte
*uncompressed_buffer
;
362 int header_size
= 12;
364 if (bfd_seek (abfd
, sectp
->filepos
, SEEK_SET
) != 0
365 || bfd_bread (compressed_buffer
,
366 compressed_size
, abfd
) != compressed_size
)
367 error (_("can't read data from '%s', section '%s'"),
368 bfd_get_filename (abfd
),
369 bfd_get_section_name (abfd
, sectp
));
371 /* Read the zlib header. In this case, it should be "ZLIB" followed
372 by the uncompressed section size, 8 bytes in big-endian order. */
373 if (compressed_size
< header_size
374 || strncmp (compressed_buffer
, "ZLIB", 4) != 0)
375 error (_("corrupt ZLIB header from '%s', section '%s'"),
376 bfd_get_filename (abfd
),
377 bfd_get_section_name (abfd
, sectp
));
378 uncompressed_size
= compressed_buffer
[4]; uncompressed_size
<<= 8;
379 uncompressed_size
+= compressed_buffer
[5]; uncompressed_size
<<= 8;
380 uncompressed_size
+= compressed_buffer
[6]; uncompressed_size
<<= 8;
381 uncompressed_size
+= compressed_buffer
[7]; uncompressed_size
<<= 8;
382 uncompressed_size
+= compressed_buffer
[8]; uncompressed_size
<<= 8;
383 uncompressed_size
+= compressed_buffer
[9]; uncompressed_size
<<= 8;
384 uncompressed_size
+= compressed_buffer
[10]; uncompressed_size
<<= 8;
385 uncompressed_size
+= compressed_buffer
[11];
387 /* It is possible the section consists of several compressed
388 buffers concatenated together, so we uncompress in a loop. */
392 strm
.avail_in
= compressed_size
- header_size
;
393 strm
.next_in
= (Bytef
*) compressed_buffer
+ header_size
;
394 strm
.avail_out
= uncompressed_size
;
395 uncompressed_buffer
= xmalloc (uncompressed_size
);
396 inner_cleanup
= make_cleanup (xfree
, uncompressed_buffer
);
397 rc
= inflateInit (&strm
);
398 while (strm
.avail_in
> 0)
401 error (_("setting up uncompression in '%s', section '%s': %d"),
402 bfd_get_filename (abfd
),
403 bfd_get_section_name (abfd
, sectp
),
405 strm
.next_out
= ((Bytef
*) uncompressed_buffer
406 + (uncompressed_size
- strm
.avail_out
));
407 rc
= inflate (&strm
, Z_FINISH
);
408 if (rc
!= Z_STREAM_END
)
409 error (_("zlib error uncompressing from '%s', section '%s': %d"),
410 bfd_get_filename (abfd
),
411 bfd_get_section_name (abfd
, sectp
),
413 rc
= inflateReset (&strm
);
415 rc
= inflateEnd (&strm
);
417 || strm
.avail_out
!= 0)
418 error (_("concluding uncompression in '%s', section '%s': %d"),
419 bfd_get_filename (abfd
),
420 bfd_get_section_name (abfd
, sectp
),
423 discard_cleanups (inner_cleanup
);
424 do_cleanups (cleanup
);
426 /* Attach the data to the BFD section. */
427 descriptor
->data
= uncompressed_buffer
;
428 descriptor
->size
= uncompressed_size
;
435 gdb_bfd_map_section (asection
*sectp
, bfd_size_type
*size
)
438 unsigned char header
[4];
439 struct gdb_bfd_section_data
*descriptor
;
441 gdb_assert ((sectp
->flags
& SEC_RELOC
) == 0);
442 gdb_assert (size
!= NULL
);
446 descriptor
= get_section_descriptor (sectp
);
448 /* If the data was already read for this BFD, just reuse it. */
449 if (descriptor
->data
!= NULL
)
452 /* Check if the file has a 4-byte header indicating compression. */
453 if (bfd_get_section_size (sectp
) > sizeof (header
)
454 && bfd_seek (abfd
, sectp
->filepos
, SEEK_SET
) == 0
455 && bfd_bread (header
, sizeof (header
), abfd
) == sizeof (header
))
457 /* Upon decompression, update the buffer and its size. */
458 if (strncmp (header
, "ZLIB", sizeof (header
)) == 0)
460 zlib_decompress_section (sectp
, descriptor
);
467 /* The page size, used when mmapping. */
471 pagesize
= getpagesize ();
473 /* Only try to mmap sections which are large enough: we don't want
474 to waste space due to fragmentation. */
476 if (bfd_get_section_size (sectp
) > 4 * pagesize
)
478 descriptor
->size
= bfd_get_section_size (sectp
);
479 descriptor
->data
= bfd_mmap (abfd
, 0, descriptor
->size
, PROT_READ
,
480 MAP_PRIVATE
, sectp
->filepos
,
481 &descriptor
->map_addr
,
482 &descriptor
->map_len
);
484 if ((caddr_t
)descriptor
->data
!= MAP_FAILED
)
486 #if HAVE_POSIX_MADVISE
487 posix_madvise (descriptor
->map_addr
, descriptor
->map_len
,
488 POSIX_MADV_WILLNEED
);
493 /* On failure, clear out the section data and try again. */
494 memset (descriptor
, 0, sizeof (*descriptor
));
497 #endif /* HAVE_MMAP */
499 /* If we get here, we are a normal, not-compressed section. */
501 descriptor
->size
= bfd_get_section_size (sectp
);
502 descriptor
->data
= xmalloc (descriptor
->size
);
504 if (bfd_seek (abfd
, sectp
->filepos
, SEEK_SET
) != 0
505 || bfd_bread (descriptor
->data
, bfd_get_section_size (sectp
),
506 abfd
) != bfd_get_section_size (sectp
))
508 xfree (descriptor
->data
);
509 descriptor
->data
= NULL
;
510 error (_("Can't read data for section '%s'"),
511 bfd_get_filename (abfd
));
515 gdb_assert (descriptor
->data
!= NULL
);
516 *size
= descriptor
->size
;
517 return descriptor
->data
;
525 gdb_bfd_fopen (const char *filename
, const char *target
, const char *mode
,
528 bfd
*result
= bfd_fopen (filename
, target
, mode
, fd
);
532 gdb_bfd_stash_filename (result
);
533 gdb_bfd_ref (result
);
542 gdb_bfd_openr (const char *filename
, const char *target
)
544 bfd
*result
= bfd_openr (filename
, target
);
548 gdb_bfd_stash_filename (result
);
549 gdb_bfd_ref (result
);
558 gdb_bfd_openw (const char *filename
, const char *target
)
560 bfd
*result
= bfd_openw (filename
, target
);
564 gdb_bfd_stash_filename (result
);
565 gdb_bfd_ref (result
);
574 gdb_bfd_openr_iovec (const char *filename
, const char *target
,
575 void *(*open_func
) (struct bfd
*nbfd
,
578 file_ptr (*pread_func
) (struct bfd
*nbfd
,
583 int (*close_func
) (struct bfd
*nbfd
,
585 int (*stat_func
) (struct bfd
*abfd
,
589 bfd
*result
= bfd_openr_iovec (filename
, target
,
590 open_func
, open_closure
,
591 pread_func
, close_func
, stat_func
);
595 gdb_bfd_ref (result
);
596 gdb_bfd_stash_filename (result
);
605 gdb_bfd_openr_next_archived_file (bfd
*archive
, bfd
*previous
)
607 bfd
*result
= bfd_openr_next_archived_file (archive
, previous
);
611 struct gdb_bfd_data
*gdata
;
613 gdb_bfd_ref (result
);
614 /* No need to stash the filename here, because we also keep a
615 reference on the parent archive. */
617 gdata
= bfd_usrdata (result
);
618 gdb_assert (gdata
->archive_bfd
== NULL
|| gdata
->archive_bfd
== archive
);
619 gdata
->archive_bfd
= archive
;
620 gdb_bfd_ref (archive
);
629 gdb_bfd_fdopenr (const char *filename
, const char *target
, int fd
)
631 bfd
*result
= bfd_fdopenr (filename
, target
, fd
);
635 gdb_bfd_ref (result
);
636 gdb_bfd_stash_filename (result
);
644 /* A callback for htab_traverse that prints a single BFD. */
647 print_one_bfd (void **slot
, void *data
)
650 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
651 struct ui_out
*uiout
= data
;
652 struct cleanup
*inner
;
654 inner
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
655 ui_out_field_int (uiout
, "refcount", gdata
->refc
);
656 ui_out_field_string (uiout
, "addr", host_address_to_string (abfd
));
657 ui_out_field_string (uiout
, "filename", bfd_get_filename (abfd
));
658 ui_out_text (uiout
, "\n");
664 /* Implement the 'maint info bfd' command. */
667 maintenance_info_bfds (char *arg
, int from_tty
)
669 struct cleanup
*cleanup
;
670 struct ui_out
*uiout
= current_uiout
;
672 cleanup
= make_cleanup_ui_out_table_begin_end (uiout
, 3, -1, "bfds");
673 ui_out_table_header (uiout
, 10, ui_left
, "refcount", "Refcount");
674 ui_out_table_header (uiout
, 18, ui_left
, "addr", "Address");
675 ui_out_table_header (uiout
, 40, ui_left
, "filename", "Filename");
677 ui_out_table_body (uiout
);
678 htab_traverse (all_bfds
, print_one_bfd
, uiout
);
680 do_cleanups (cleanup
);
683 /* -Wmissing-prototypes */
684 extern initialize_file_ftype _initialize_gdb_bfd
;
687 _initialize_gdb_bfd (void)
689 all_bfds
= htab_create_alloc (10, htab_hash_pointer
, htab_eq_pointer
,
690 NULL
, xcalloc
, xfree
);
692 add_cmd ("bfds", class_maintenance
, maintenance_info_bfds
, _("\
693 List the BFDs that are currently open."),
694 &maintenanceinfolist
);