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. */
90 /* A hash table storing all the BFDs maintained in the cache. */
92 static htab_t gdb_bfd_cache
;
94 /* The type of an object being looked up in gdb_bfd_cache. We use
95 htab's capability of storing one kind of object (BFD in this case)
96 and using a different sort of object for searching. */
98 struct gdb_bfd_cache_search
101 const char *filename
;
106 /* A hash function for BFDs. */
109 hash_bfd (const void *b
)
113 /* It is simplest to just hash the filename. */
114 return htab_hash_string (bfd_get_filename (abfd
));
117 /* An equality function for BFDs. Note that this expects the caller
118 to search using struct gdb_bfd_cache_search only, not BFDs. */
121 eq_bfd (const void *a
, const void *b
)
124 const struct gdb_bfd_cache_search
*s
= b
;
125 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
127 return (gdata
->mtime
== s
->mtime
128 && strcmp (bfd_get_filename (abfd
), s
->filename
) == 0);
134 gdb_bfd_open (const char *name
, const char *target
, int fd
)
139 struct gdb_bfd_cache_search search
;
142 if (gdb_bfd_cache
== NULL
)
143 gdb_bfd_cache
= htab_create_alloc (1, hash_bfd
, eq_bfd
, NULL
,
148 fd
= open (name
, O_RDONLY
| O_BINARY
);
151 bfd_set_error (bfd_error_system_call
);
156 search
.filename
= name
;
157 if (fstat (fd
, &st
) < 0)
159 /* Weird situation here. */
163 search
.mtime
= st
.st_mtime
;
165 /* Note that this must compute the same result as hash_bfd. */
166 hash
= htab_hash_string (name
);
167 /* Note that we cannot use htab_find_slot_with_hash here, because
168 opening the BFD may fail; and this would violate hashtab
170 abfd
= htab_find_with_hash (gdb_bfd_cache
, &search
, hash
);
178 abfd
= bfd_fopen (name
, target
, FOPEN_RB
, fd
);
182 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
, INSERT
);
186 gdb_bfd_stash_filename (abfd
);
191 /* A helper function that releases any section data attached to the
195 free_one_bfd_section (bfd
*abfd
, asection
*sectp
, void *ignore
)
197 struct gdb_bfd_section_data
*sect
= bfd_get_section_userdata (abfd
, sectp
);
199 if (sect
!= NULL
&& sect
->data
!= NULL
)
202 if (sect
->map_addr
!= NULL
)
206 res
= munmap (sect
->map_addr
, sect
->map_len
);
207 gdb_assert (res
== 0);
215 /* Close ABFD, and warn if that fails. */
218 gdb_bfd_close_or_warn (struct bfd
*abfd
)
221 char *name
= bfd_get_filename (abfd
);
223 bfd_map_over_sections (abfd
, free_one_bfd_section
, NULL
);
225 ret
= bfd_close (abfd
);
228 warning (_("cannot close \"%s\": %s"),
229 name
, bfd_errmsg (bfd_get_error ()));
237 gdb_bfd_ref (struct bfd
*abfd
)
239 struct gdb_bfd_data
*gdata
;
245 gdata
= bfd_usrdata (abfd
);
253 gdata
= bfd_zalloc (abfd
, sizeof (struct gdb_bfd_data
));
255 gdata
->mtime
= bfd_get_mtime (abfd
);
256 gdata
->archive_bfd
= NULL
;
257 bfd_usrdata (abfd
) = gdata
;
259 /* This is the first we've seen it, so add it to the hash table. */
260 slot
= htab_find_slot (all_bfds
, abfd
, INSERT
);
261 gdb_assert (slot
&& !*slot
);
268 gdb_bfd_unref (struct bfd
*abfd
)
270 struct gdb_bfd_data
*gdata
;
271 struct gdb_bfd_cache_search search
;
277 gdata
= bfd_usrdata (abfd
);
278 gdb_assert (gdata
->refc
>= 1);
284 archive_bfd
= gdata
->archive_bfd
;
285 search
.filename
= bfd_get_filename (abfd
);
287 if (gdb_bfd_cache
&& search
.filename
)
289 hashval_t hash
= htab_hash_string (search
.filename
);
292 search
.mtime
= gdata
->mtime
;
293 slot
= htab_find_slot_with_hash (gdb_bfd_cache
, &search
, hash
,
297 htab_clear_slot (gdb_bfd_cache
, slot
);
300 bfd_usrdata (abfd
) = NULL
; /* Paranoia. */
302 htab_remove_elt (all_bfds
, abfd
);
304 gdb_bfd_close_or_warn (abfd
);
306 gdb_bfd_unref (archive_bfd
);
309 /* A helper function that returns the section data descriptor
310 associated with SECTION. If no such descriptor exists, a new one
311 is allocated and cleared. */
313 static struct gdb_bfd_section_data
*
314 get_section_descriptor (asection
*section
)
316 struct gdb_bfd_section_data
*result
;
318 result
= bfd_get_section_userdata (section
->owner
, section
);
322 result
= bfd_zalloc (section
->owner
, sizeof (*result
));
323 bfd_set_section_userdata (section
->owner
, section
, result
);
329 /* Decompress a section that was compressed using zlib. Store the
330 decompressed buffer, and its size, in DESCRIPTOR. */
333 zlib_decompress_section (asection
*sectp
,
334 struct gdb_bfd_section_data
*descriptor
)
336 bfd
*abfd
= sectp
->owner
;
338 error (_("Support for zlib-compressed data (from '%s', section '%s') "
339 "is disabled in this copy of GDB"),
340 bfd_get_filename (abfd
),
341 bfd_get_section_name (abfd
, sectp
));
343 bfd_size_type compressed_size
= bfd_get_section_size (sectp
);
344 gdb_byte
*compressed_buffer
= xmalloc (compressed_size
);
345 struct cleanup
*cleanup
= make_cleanup (xfree
, compressed_buffer
);
346 struct cleanup
*inner_cleanup
;
347 bfd_size_type uncompressed_size
;
348 gdb_byte
*uncompressed_buffer
;
351 int header_size
= 12;
353 if (bfd_seek (abfd
, sectp
->filepos
, SEEK_SET
) != 0
354 || bfd_bread (compressed_buffer
,
355 compressed_size
, abfd
) != compressed_size
)
356 error (_("can't read data from '%s', section '%s'"),
357 bfd_get_filename (abfd
),
358 bfd_get_section_name (abfd
, sectp
));
360 /* Read the zlib header. In this case, it should be "ZLIB" followed
361 by the uncompressed section size, 8 bytes in big-endian order. */
362 if (compressed_size
< header_size
363 || strncmp (compressed_buffer
, "ZLIB", 4) != 0)
364 error (_("corrupt ZLIB header from '%s', section '%s'"),
365 bfd_get_filename (abfd
),
366 bfd_get_section_name (abfd
, sectp
));
367 uncompressed_size
= compressed_buffer
[4]; uncompressed_size
<<= 8;
368 uncompressed_size
+= compressed_buffer
[5]; uncompressed_size
<<= 8;
369 uncompressed_size
+= compressed_buffer
[6]; uncompressed_size
<<= 8;
370 uncompressed_size
+= compressed_buffer
[7]; uncompressed_size
<<= 8;
371 uncompressed_size
+= compressed_buffer
[8]; uncompressed_size
<<= 8;
372 uncompressed_size
+= compressed_buffer
[9]; uncompressed_size
<<= 8;
373 uncompressed_size
+= compressed_buffer
[10]; uncompressed_size
<<= 8;
374 uncompressed_size
+= compressed_buffer
[11];
376 /* It is possible the section consists of several compressed
377 buffers concatenated together, so we uncompress in a loop. */
381 strm
.avail_in
= compressed_size
- header_size
;
382 strm
.next_in
= (Bytef
*) compressed_buffer
+ header_size
;
383 strm
.avail_out
= uncompressed_size
;
384 uncompressed_buffer
= xmalloc (uncompressed_size
);
385 inner_cleanup
= make_cleanup (xfree
, uncompressed_buffer
);
386 rc
= inflateInit (&strm
);
387 while (strm
.avail_in
> 0)
390 error (_("setting up uncompression in '%s', section '%s': %d"),
391 bfd_get_filename (abfd
),
392 bfd_get_section_name (abfd
, sectp
),
394 strm
.next_out
= ((Bytef
*) uncompressed_buffer
395 + (uncompressed_size
- strm
.avail_out
));
396 rc
= inflate (&strm
, Z_FINISH
);
397 if (rc
!= Z_STREAM_END
)
398 error (_("zlib error uncompressing from '%s', section '%s': %d"),
399 bfd_get_filename (abfd
),
400 bfd_get_section_name (abfd
, sectp
),
402 rc
= inflateReset (&strm
);
404 rc
= inflateEnd (&strm
);
406 || strm
.avail_out
!= 0)
407 error (_("concluding uncompression in '%s', section '%s': %d"),
408 bfd_get_filename (abfd
),
409 bfd_get_section_name (abfd
, sectp
),
412 discard_cleanups (inner_cleanup
);
413 do_cleanups (cleanup
);
415 /* Attach the data to the BFD section. */
416 descriptor
->data
= uncompressed_buffer
;
417 descriptor
->size
= uncompressed_size
;
424 gdb_bfd_map_section (asection
*sectp
, bfd_size_type
*size
)
427 unsigned char header
[4];
428 struct gdb_bfd_section_data
*descriptor
;
430 gdb_assert ((sectp
->flags
& SEC_RELOC
) == 0);
431 gdb_assert (size
!= NULL
);
435 descriptor
= get_section_descriptor (sectp
);
437 /* If the data was already read for this BFD, just reuse it. */
438 if (descriptor
->data
!= NULL
)
441 /* Check if the file has a 4-byte header indicating compression. */
442 if (bfd_get_section_size (sectp
) > sizeof (header
)
443 && bfd_seek (abfd
, sectp
->filepos
, SEEK_SET
) == 0
444 && bfd_bread (header
, sizeof (header
), abfd
) == sizeof (header
))
446 /* Upon decompression, update the buffer and its size. */
447 if (strncmp (header
, "ZLIB", sizeof (header
)) == 0)
449 zlib_decompress_section (sectp
, descriptor
);
456 /* The page size, used when mmapping. */
460 pagesize
= getpagesize ();
462 /* Only try to mmap sections which are large enough: we don't want
463 to waste space due to fragmentation. */
465 if (bfd_get_section_size (sectp
) > 4 * pagesize
)
467 descriptor
->size
= bfd_get_section_size (sectp
);
468 descriptor
->data
= bfd_mmap (abfd
, 0, descriptor
->size
, PROT_READ
,
469 MAP_PRIVATE
, sectp
->filepos
,
470 &descriptor
->map_addr
,
471 &descriptor
->map_len
);
473 if ((caddr_t
)descriptor
->data
!= MAP_FAILED
)
475 #if HAVE_POSIX_MADVISE
476 posix_madvise (descriptor
->map_addr
, descriptor
->map_len
,
477 POSIX_MADV_WILLNEED
);
482 /* On failure, clear out the section data and try again. */
483 memset (descriptor
, 0, sizeof (*descriptor
));
486 #endif /* HAVE_MMAP */
488 /* If we get here, we are a normal, not-compressed section. */
490 descriptor
->size
= bfd_get_section_size (sectp
);
491 descriptor
->data
= xmalloc (descriptor
->size
);
493 if (bfd_seek (abfd
, sectp
->filepos
, SEEK_SET
) != 0
494 || bfd_bread (descriptor
->data
, bfd_get_section_size (sectp
),
495 abfd
) != bfd_get_section_size (sectp
))
497 xfree (descriptor
->data
);
498 descriptor
->data
= NULL
;
499 error (_("Can't read data for section '%s'"),
500 bfd_get_filename (abfd
));
504 gdb_assert (descriptor
->data
!= NULL
);
505 *size
= descriptor
->size
;
506 return descriptor
->data
;
514 gdb_bfd_fopen (const char *filename
, const char *target
, const char *mode
,
517 bfd
*result
= bfd_fopen (filename
, target
, mode
, fd
);
521 gdb_bfd_stash_filename (result
);
522 gdb_bfd_ref (result
);
531 gdb_bfd_openr (const char *filename
, const char *target
)
533 bfd
*result
= bfd_openr (filename
, target
);
537 gdb_bfd_stash_filename (result
);
538 gdb_bfd_ref (result
);
547 gdb_bfd_openw (const char *filename
, const char *target
)
549 bfd
*result
= bfd_openw (filename
, target
);
553 gdb_bfd_stash_filename (result
);
554 gdb_bfd_ref (result
);
563 gdb_bfd_openr_iovec (const char *filename
, const char *target
,
564 void *(*open_func
) (struct bfd
*nbfd
,
567 file_ptr (*pread_func
) (struct bfd
*nbfd
,
572 int (*close_func
) (struct bfd
*nbfd
,
574 int (*stat_func
) (struct bfd
*abfd
,
578 bfd
*result
= bfd_openr_iovec (filename
, target
,
579 open_func
, open_closure
,
580 pread_func
, close_func
, stat_func
);
584 gdb_bfd_ref (result
);
585 gdb_bfd_stash_filename (result
);
594 gdb_bfd_openr_next_archived_file (bfd
*archive
, bfd
*previous
)
596 bfd
*result
= bfd_openr_next_archived_file (archive
, previous
);
600 struct gdb_bfd_data
*gdata
;
602 gdb_bfd_ref (result
);
603 /* No need to stash the filename here, because we also keep a
604 reference on the parent archive. */
606 gdata
= bfd_usrdata (result
);
607 gdb_assert (gdata
->archive_bfd
== NULL
|| gdata
->archive_bfd
== archive
);
608 gdata
->archive_bfd
= archive
;
609 gdb_bfd_ref (archive
);
618 gdb_bfd_fdopenr (const char *filename
, const char *target
, int fd
)
620 bfd
*result
= bfd_fdopenr (filename
, target
, fd
);
624 gdb_bfd_ref (result
);
625 gdb_bfd_stash_filename (result
);
633 /* A callback for htab_traverse that prints a single BFD. */
636 print_one_bfd (void **slot
, void *data
)
639 struct gdb_bfd_data
*gdata
= bfd_usrdata (abfd
);
640 struct ui_out
*uiout
= data
;
641 struct cleanup
*inner
;
643 inner
= make_cleanup_ui_out_tuple_begin_end (uiout
, NULL
);
644 ui_out_field_int (uiout
, "refcount", gdata
->refc
);
645 ui_out_field_string (uiout
, "addr", host_address_to_string (abfd
));
646 ui_out_field_string (uiout
, "filename", bfd_get_filename (abfd
));
647 ui_out_text (uiout
, "\n");
653 /* Implement the 'maint info bfd' command. */
656 maintenance_info_bfds (char *arg
, int from_tty
)
658 struct cleanup
*cleanup
;
659 struct ui_out
*uiout
= current_uiout
;
661 cleanup
= make_cleanup_ui_out_table_begin_end (uiout
, 3, -1, "bfds");
662 ui_out_table_header (uiout
, 10, ui_left
, "refcount", "Refcount");
663 ui_out_table_header (uiout
, 18, ui_left
, "addr", "Address");
664 ui_out_table_header (uiout
, 40, ui_left
, "filename", "Filename");
666 ui_out_table_body (uiout
);
667 htab_traverse (all_bfds
, print_one_bfd
, uiout
);
669 do_cleanups (cleanup
);
672 /* -Wmissing-prototypes */
673 extern initialize_file_ftype _initialize_gdb_bfd
;
676 _initialize_gdb_bfd (void)
678 all_bfds
= htab_create_alloc (10, htab_hash_pointer
, htab_eq_pointer
,
679 NULL
, xcalloc
, xfree
);
681 add_cmd ("bfds", class_maintenance
, maintenance_info_bfds
, _("\
682 List the BFDs that are currently open."),
683 &maintenanceinfolist
);