1 /* Plugin support for BFD.
2 Copyright (C) 2009-2016 Free Software Foundation, Inc.
3
4 This file is part of BFD, the Binary File Descriptor library.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
20
21 #include "sysdep.h"
22 #include "bfd.h"
23
24 #if BFD_SUPPORTS_PLUGINS
25
26 #include <assert.h>
27 #ifdef HAVE_DLFCN_H
28 #include <dlfcn.h>
29 #elif defined (HAVE_WINDOWS_H)
30 #include <windows.h>
31 #else
32 #error Unknown how to handle dynamic-load-libraries.
33 #endif
34 #include <stdarg.h>
35 #include "plugin-api.h"
36 #include "plugin.h"
37 #include "libbfd.h"
38 #include "libiberty.h"
39 #include <dirent.h>
40
41 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
42
43 #define RTLD_NOW 0 /* Dummy value. */
44
45 static void *
dlopen(const char * file,int mode ATTRIBUTE_UNUSED)46 dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
47 {
48 return LoadLibrary (file);
49 }
50
51 static void *
dlsym(void * handle,const char * name)52 dlsym (void *handle, const char *name)
53 {
54 return GetProcAddress (handle, name);
55 }
56
57 static int ATTRIBUTE_UNUSED
dlclose(void * handle)58 dlclose (void *handle)
59 {
60 FreeLibrary (handle);
61 return 0;
62 }
63
64 static const char *
dlerror(void)65 dlerror (void)
66 {
67 return "Unable to load DLL.";
68 }
69
70 #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */
71
72 #define bfd_plugin_close_and_cleanup _bfd_generic_close_and_cleanup
73 #define bfd_plugin_bfd_free_cached_info _bfd_generic_bfd_free_cached_info
74 #define bfd_plugin_new_section_hook _bfd_generic_new_section_hook
75 #define bfd_plugin_get_section_contents _bfd_generic_get_section_contents
76 #define bfd_plugin_get_section_contents_in_window _bfd_generic_get_section_contents_in_window
77 #define bfd_plugin_bfd_copy_private_header_data _bfd_generic_bfd_copy_private_header_data
78 #define bfd_plugin_bfd_merge_private_bfd_data _bfd_generic_bfd_merge_private_bfd_data
79 #define bfd_plugin_bfd_copy_private_header_data _bfd_generic_bfd_copy_private_header_data
80 #define bfd_plugin_bfd_set_private_flags _bfd_generic_bfd_set_private_flags
81 #define bfd_plugin_core_file_matches_executable_p generic_core_file_matches_executable_p
82 #define bfd_plugin_bfd_is_local_label_name _bfd_nosymbols_bfd_is_local_label_name
83 #define bfd_plugin_bfd_is_target_special_symbol ((bfd_boolean (*) (bfd *, asymbol *)) bfd_false)
84 #define bfd_plugin_get_lineno _bfd_nosymbols_get_lineno
85 #define bfd_plugin_find_nearest_line _bfd_nosymbols_find_nearest_line
86 #define bfd_plugin_find_line _bfd_nosymbols_find_line
87 #define bfd_plugin_find_inliner_info _bfd_nosymbols_find_inliner_info
88 #define bfd_plugin_get_symbol_version_string _bfd_nosymbols_get_symbol_version_string
89 #define bfd_plugin_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol
90 #define bfd_plugin_read_minisymbols _bfd_generic_read_minisymbols
91 #define bfd_plugin_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol
92 #define bfd_plugin_set_arch_mach bfd_default_set_arch_mach
93 #define bfd_plugin_set_section_contents _bfd_generic_set_section_contents
94 #define bfd_plugin_bfd_get_relocated_section_contents bfd_generic_get_relocated_section_contents
95 #define bfd_plugin_bfd_relax_section bfd_generic_relax_section
96 #define bfd_plugin_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
97 #define bfd_plugin_bfd_link_add_symbols _bfd_generic_link_add_symbols
98 #define bfd_plugin_bfd_link_just_syms _bfd_generic_link_just_syms
99 #define bfd_plugin_bfd_final_link _bfd_generic_final_link
100 #define bfd_plugin_bfd_link_split_section _bfd_generic_link_split_section
101 #define bfd_plugin_bfd_gc_sections bfd_generic_gc_sections
102 #define bfd_plugin_bfd_lookup_section_flags bfd_generic_lookup_section_flags
103 #define bfd_plugin_bfd_merge_sections bfd_generic_merge_sections
104 #define bfd_plugin_bfd_is_group_section bfd_generic_is_group_section
105 #define bfd_plugin_bfd_discard_group bfd_generic_discard_group
106 #define bfd_plugin_section_already_linked _bfd_generic_section_already_linked
107 #define bfd_plugin_bfd_define_common_symbol bfd_generic_define_common_symbol
108 #define bfd_plugin_bfd_copy_link_hash_symbol_type _bfd_generic_copy_link_hash_symbol_type
109 #define bfd_plugin_bfd_link_check_relocs _bfd_generic_link_check_relocs
110
111 static enum ld_plugin_status
message(int level ATTRIBUTE_UNUSED,const char * format,...)112 message (int level ATTRIBUTE_UNUSED,
113 const char * format, ...)
114 {
115 va_list args;
116 va_start (args, format);
117 printf ("bfd plugin: ");
118 vprintf (format, args);
119 putchar ('\n');
120 va_end (args);
121 return LDPS_OK;
122 }
123
124 /* Register a claim-file handler. */
125 static ld_plugin_claim_file_handler claim_file;
126
127 static enum ld_plugin_status
register_claim_file(ld_plugin_claim_file_handler handler)128 register_claim_file (ld_plugin_claim_file_handler handler)
129 {
130 claim_file = handler;
131 return LDPS_OK;
132 }
133
134 static enum ld_plugin_status
add_symbols(void * handle,int nsyms,const struct ld_plugin_symbol * syms)135 add_symbols (void * handle,
136 int nsyms,
137 const struct ld_plugin_symbol * syms)
138 {
139 bfd *abfd = handle;
140 struct plugin_data_struct *plugin_data =
141 bfd_alloc (abfd, sizeof (plugin_data_struct));
142
143 plugin_data->nsyms = nsyms;
144 plugin_data->syms = syms;
145
146 if (nsyms != 0)
147 abfd->flags |= HAS_SYMS;
148
149 abfd->tdata.plugin_data = plugin_data;
150 return LDPS_OK;
151 }
152
153 static const char *plugin_program_name;
154
155 void
bfd_plugin_set_program_name(const char * program_name)156 bfd_plugin_set_program_name (const char *program_name)
157 {
158 plugin_program_name = program_name;
159 }
160
161 static int
try_claim(bfd * abfd)162 try_claim (bfd *abfd)
163 {
164 int claimed = 0;
165 struct ld_plugin_input_file file;
166 bfd *iobfd;
167
168 file.name = abfd->filename;
169
170 if (abfd->my_archive && !bfd_is_thin_archive (abfd->my_archive))
171 {
172 iobfd = abfd->my_archive;
173 file.offset = abfd->origin;
174 file.filesize = arelt_size (abfd);
175 }
176 else
177 {
178 iobfd = abfd;
179 file.offset = 0;
180 file.filesize = 0;
181 }
182
183 if (!iobfd->iostream && !bfd_open_file (iobfd))
184 return 0;
185
186 file.fd = fileno ((FILE *) iobfd->iostream);
187
188 if (!abfd->my_archive || bfd_is_thin_archive (abfd->my_archive))
189 {
190 struct stat stat_buf;
191 if (fstat (file.fd, &stat_buf))
192 return 0;
193 file.filesize = stat_buf.st_size;
194 }
195
196 file.handle = abfd;
197 off_t cur_offset = lseek(file.fd, 0, SEEK_CUR);
198 claim_file (&file, &claimed);
199 lseek(file.fd, cur_offset, SEEK_SET);
200 if (!claimed)
201 return 0;
202
203 return 1;
204 }
205
206 static int
try_load_plugin(const char * pname,bfd * abfd,int * has_plugin_p)207 try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p)
208 {
209 void *plugin_handle;
210 struct ld_plugin_tv tv[4];
211 int i;
212 ld_plugin_onload onload;
213 enum ld_plugin_status status;
214
215 *has_plugin_p = 0;
216
217 plugin_handle = dlopen (pname, RTLD_NOW);
218 if (!plugin_handle)
219 {
220 (*_bfd_error_handler)("%s\n", dlerror ());
221 return 0;
222 }
223
224 onload = dlsym (plugin_handle, "onload");
225 if (!onload)
226 goto err;
227
228 i = 0;
229 tv[i].tv_tag = LDPT_MESSAGE;
230 tv[i].tv_u.tv_message = message;
231
232 ++i;
233 tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
234 tv[i].tv_u.tv_register_claim_file = register_claim_file;
235
236 ++i;
237 tv[i].tv_tag = LDPT_ADD_SYMBOLS;
238 tv[i].tv_u.tv_add_symbols = add_symbols;
239
240 ++i;
241 tv[i].tv_tag = LDPT_NULL;
242 tv[i].tv_u.tv_val = 0;
243
244 status = (*onload)(tv);
245
246 if (status != LDPS_OK)
247 goto err;
248
249 *has_plugin_p = 1;
250
251 abfd->plugin_format = bfd_plugin_no;
252
253 if (!claim_file)
254 goto err;
255
256 if (!try_claim (abfd))
257 goto err;
258
259 abfd->plugin_format = bfd_plugin_yes;
260
261 return 1;
262
263 err:
264 return 0;
265 }
266
267 /* There may be plugin libraries in lib/bfd-plugins. */
268
269 static int has_plugin = -1;
270
271 static const bfd_target *(*ld_plugin_object_p) (bfd *);
272
273 static const char *plugin_name;
274
275 void
bfd_plugin_set_plugin(const char * p)276 bfd_plugin_set_plugin (const char *p)
277 {
278 plugin_name = p;
279 has_plugin = p != NULL;
280 }
281
282 /* Return TRUE if a plugin library is used. */
283
284 bfd_boolean
bfd_plugin_specified_p(void)285 bfd_plugin_specified_p (void)
286 {
287 return has_plugin > 0;
288 }
289
290 /* Return TRUE if ABFD can be claimed by linker LTO plugin. */
291
292 bfd_boolean
bfd_link_plugin_object_p(bfd * abfd)293 bfd_link_plugin_object_p (bfd *abfd)
294 {
295 if (ld_plugin_object_p)
296 return ld_plugin_object_p (abfd) != NULL;
297 return FALSE;
298 }
299
300 extern const bfd_target plugin_vec;
301
302 /* Return TRUE if TARGET is a pointer to plugin_vec. */
303
304 bfd_boolean
bfd_plugin_target_p(const bfd_target * target)305 bfd_plugin_target_p (const bfd_target *target)
306 {
307 return target == &plugin_vec;
308 }
309
310 /* Register OBJECT_P to be used by bfd_plugin_object_p. */
311
312 void
register_ld_plugin_object_p(const bfd_target * (* object_p)(bfd *))313 register_ld_plugin_object_p (const bfd_target *(*object_p) (bfd *))
314 {
315 ld_plugin_object_p = object_p;
316 }
317
318 static int
load_plugin(bfd * abfd)319 load_plugin (bfd *abfd)
320 {
321 char *plugin_dir;
322 char *p;
323 DIR *d;
324 struct dirent *ent;
325 int found = 0;
326
327 if (!has_plugin)
328 return found;
329
330 if (plugin_name)
331 return try_load_plugin (plugin_name, abfd, &has_plugin);
332
333 if (plugin_program_name == NULL)
334 return found;
335
336 plugin_dir = concat (BINDIR, "/../lib/bfd-plugins", NULL);
337 p = make_relative_prefix (plugin_program_name,
338 BINDIR,
339 plugin_dir);
340 free (plugin_dir);
341 plugin_dir = NULL;
342
343 d = opendir (p);
344 if (!d)
345 goto out;
346
347 while ((ent = readdir (d)))
348 {
349 char *full_name;
350 struct stat s;
351 int valid_plugin;
352
353 full_name = concat (p, "/", ent->d_name, NULL);
354 if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
355 found = try_load_plugin (full_name, abfd, &valid_plugin);
356 if (has_plugin <= 0)
357 has_plugin = valid_plugin;
358 free (full_name);
359 if (found)
360 break;
361 }
362
363 out:
364 free (p);
365 if (d)
366 closedir (d);
367
368 return found;
369 }
370
371
372 static const bfd_target *
bfd_plugin_object_p(bfd * abfd)373 bfd_plugin_object_p (bfd *abfd)
374 {
375 if (ld_plugin_object_p)
376 return ld_plugin_object_p (abfd);
377
378 if (abfd->plugin_format == bfd_plugin_unknown && !load_plugin (abfd))
379 return NULL;
380
381 return abfd->plugin_format == bfd_plugin_yes ? abfd->xvec : NULL;
382 }
383
384 /* Copy any private info we understand from the input bfd
385 to the output bfd. */
386
387 static bfd_boolean
bfd_plugin_bfd_copy_private_bfd_data(bfd * ibfd ATTRIBUTE_UNUSED,bfd * obfd ATTRIBUTE_UNUSED)388 bfd_plugin_bfd_copy_private_bfd_data (bfd *ibfd ATTRIBUTE_UNUSED,
389 bfd *obfd ATTRIBUTE_UNUSED)
390 {
391 BFD_ASSERT (0);
392 return TRUE;
393 }
394
395 /* Copy any private info we understand from the input section
396 to the output section. */
397
398 static bfd_boolean
bfd_plugin_bfd_copy_private_section_data(bfd * ibfd ATTRIBUTE_UNUSED,asection * isection ATTRIBUTE_UNUSED,bfd * obfd ATTRIBUTE_UNUSED,asection * osection ATTRIBUTE_UNUSED)399 bfd_plugin_bfd_copy_private_section_data (bfd *ibfd ATTRIBUTE_UNUSED,
400 asection *isection ATTRIBUTE_UNUSED,
401 bfd *obfd ATTRIBUTE_UNUSED,
402 asection *osection ATTRIBUTE_UNUSED)
403 {
404 BFD_ASSERT (0);
405 return TRUE;
406 }
407
408 /* Copy any private info we understand from the input symbol
409 to the output symbol. */
410
411 static bfd_boolean
bfd_plugin_bfd_copy_private_symbol_data(bfd * ibfd ATTRIBUTE_UNUSED,asymbol * isymbol ATTRIBUTE_UNUSED,bfd * obfd ATTRIBUTE_UNUSED,asymbol * osymbol ATTRIBUTE_UNUSED)412 bfd_plugin_bfd_copy_private_symbol_data (bfd *ibfd ATTRIBUTE_UNUSED,
413 asymbol *isymbol ATTRIBUTE_UNUSED,
414 bfd *obfd ATTRIBUTE_UNUSED,
415 asymbol *osymbol ATTRIBUTE_UNUSED)
416 {
417 BFD_ASSERT (0);
418 return TRUE;
419 }
420
421 static bfd_boolean
bfd_plugin_bfd_print_private_bfd_data(bfd * abfd ATTRIBUTE_UNUSED,PTR ptr ATTRIBUTE_UNUSED)422 bfd_plugin_bfd_print_private_bfd_data (bfd *abfd ATTRIBUTE_UNUSED, PTR ptr ATTRIBUTE_UNUSED)
423 {
424 BFD_ASSERT (0);
425 return TRUE;
426 }
427
428 static char *
bfd_plugin_core_file_failing_command(bfd * abfd ATTRIBUTE_UNUSED)429 bfd_plugin_core_file_failing_command (bfd *abfd ATTRIBUTE_UNUSED)
430 {
431 BFD_ASSERT (0);
432 return NULL;
433 }
434
435 static int
bfd_plugin_core_file_failing_signal(bfd * abfd ATTRIBUTE_UNUSED)436 bfd_plugin_core_file_failing_signal (bfd *abfd ATTRIBUTE_UNUSED)
437 {
438 BFD_ASSERT (0);
439 return 0;
440 }
441
442 static int
bfd_plugin_core_file_pid(bfd * abfd ATTRIBUTE_UNUSED)443 bfd_plugin_core_file_pid (bfd *abfd ATTRIBUTE_UNUSED)
444 {
445 BFD_ASSERT (0);
446 return 0;
447 }
448
449 static long
bfd_plugin_get_symtab_upper_bound(bfd * abfd)450 bfd_plugin_get_symtab_upper_bound (bfd *abfd)
451 {
452 struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
453 long nsyms = plugin_data->nsyms;
454
455 BFD_ASSERT (nsyms >= 0);
456
457 return ((nsyms + 1) * sizeof (asymbol *));
458 }
459
460 static flagword
convert_flags(const struct ld_plugin_symbol * sym)461 convert_flags (const struct ld_plugin_symbol *sym)
462 {
463 switch (sym->def)
464 {
465 case LDPK_DEF:
466 case LDPK_COMMON:
467 case LDPK_UNDEF:
468 return BSF_GLOBAL;
469
470 case LDPK_WEAKUNDEF:
471 case LDPK_WEAKDEF:
472 return BSF_GLOBAL | BSF_WEAK;
473
474 default:
475 BFD_ASSERT (0);
476 return 0;
477 }
478 }
479
480 static long
bfd_plugin_canonicalize_symtab(bfd * abfd,asymbol ** alocation)481 bfd_plugin_canonicalize_symtab (bfd *abfd,
482 asymbol **alocation)
483 {
484 struct plugin_data_struct *plugin_data = abfd->tdata.plugin_data;
485 long nsyms = plugin_data->nsyms;
486 const struct ld_plugin_symbol *syms = plugin_data->syms;
487 static asection fake_section;
488 static asection fake_common_section;
489 int i;
490
491 fake_section.name = ".text";
492 fake_common_section.flags = SEC_IS_COMMON;
493
494 for (i = 0; i < nsyms; i++)
495 {
496 asymbol *s = bfd_alloc (abfd, sizeof (asymbol));
497
498 BFD_ASSERT (s);
499 alocation[i] = s;
500
501 s->the_bfd = abfd;
502 s->name = syms[i].name;
503 s->value = 0;
504 s->flags = convert_flags (&syms[i]);
505 switch (syms[i].def)
506 {
507 case LDPK_COMMON:
508 s->section = &fake_common_section;
509 break;
510 case LDPK_UNDEF:
511 case LDPK_WEAKUNDEF:
512 s->section = bfd_und_section_ptr;
513 break;
514 case LDPK_DEF:
515 case LDPK_WEAKDEF:
516 s->section = &fake_section;
517 break;
518 default:
519 BFD_ASSERT (0);
520 }
521
522 s->udata.p = (void *) &syms[i];
523 }
524
525 return nsyms;
526 }
527
528 static void
bfd_plugin_print_symbol(bfd * abfd ATTRIBUTE_UNUSED,PTR afile ATTRIBUTE_UNUSED,asymbol * symbol ATTRIBUTE_UNUSED,bfd_print_symbol_type how ATTRIBUTE_UNUSED)529 bfd_plugin_print_symbol (bfd *abfd ATTRIBUTE_UNUSED,
530 PTR afile ATTRIBUTE_UNUSED,
531 asymbol *symbol ATTRIBUTE_UNUSED,
532 bfd_print_symbol_type how ATTRIBUTE_UNUSED)
533 {
534 BFD_ASSERT (0);
535 }
536
537 static void
bfd_plugin_get_symbol_info(bfd * abfd ATTRIBUTE_UNUSED,asymbol * symbol,symbol_info * ret)538 bfd_plugin_get_symbol_info (bfd *abfd ATTRIBUTE_UNUSED,
539 asymbol *symbol,
540 symbol_info *ret)
541 {
542 bfd_symbol_info (symbol, ret);
543 }
544
545 /* Make an empty symbol. */
546
547 static asymbol *
bfd_plugin_make_empty_symbol(bfd * abfd)548 bfd_plugin_make_empty_symbol (bfd *abfd)
549 {
550 asymbol *new_symbol = bfd_zalloc (abfd, sizeof (asymbol));
551 if (new_symbol == NULL)
552 return new_symbol;
553 new_symbol->the_bfd = abfd;
554 return new_symbol;
555 }
556
557 static int
bfd_plugin_sizeof_headers(bfd * a ATTRIBUTE_UNUSED,struct bfd_link_info * info ATTRIBUTE_UNUSED)558 bfd_plugin_sizeof_headers (bfd *a ATTRIBUTE_UNUSED,
559 struct bfd_link_info *info ATTRIBUTE_UNUSED)
560 {
561 BFD_ASSERT (0);
562 return 0;
563 }
564
565 const bfd_target plugin_vec =
566 {
567 "plugin", /* Name. */
568 bfd_target_unknown_flavour,
569 BFD_ENDIAN_LITTLE, /* Target byte order. */
570 BFD_ENDIAN_LITTLE, /* Target headers byte order. */
571 (HAS_RELOC | EXEC_P | /* Object flags. */
572 HAS_LINENO | HAS_DEBUG |
573 HAS_SYMS | HAS_LOCALS | DYNAMIC | WP_TEXT | D_PAGED),
574 (SEC_CODE | SEC_DATA | SEC_ROM | SEC_HAS_CONTENTS
575 | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* Section flags. */
576 0, /* symbol_leading_char. */
577 '/', /* ar_pad_char. */
578 15, /* ar_max_namelen. */
579 255, /* match priority. */
580
581 bfd_getl64, bfd_getl_signed_64, bfd_putl64,
582 bfd_getl32, bfd_getl_signed_32, bfd_putl32,
583 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
584 bfd_getl64, bfd_getl_signed_64, bfd_putl64,
585 bfd_getl32, bfd_getl_signed_32, bfd_putl32,
586 bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
587
588 { /* bfd_check_format. */
589 _bfd_dummy_target,
590 bfd_plugin_object_p,
591 bfd_generic_archive_p,
592 _bfd_dummy_target
593 },
594 { /* bfd_set_format. */
595 bfd_false,
596 bfd_false,
597 _bfd_generic_mkarchive,
598 bfd_false,
599 },
600 { /* bfd_write_contents. */
601 bfd_false,
602 bfd_false,
603 _bfd_write_archive_contents,
604 bfd_false,
605 },
606
607 BFD_JUMP_TABLE_GENERIC (bfd_plugin),
608 BFD_JUMP_TABLE_COPY (bfd_plugin),
609 BFD_JUMP_TABLE_CORE (bfd_plugin),
610 #ifdef USE_64_BIT_ARCHIVE
611 BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_64_bit),
612 #else
613 BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
614 #endif
615 BFD_JUMP_TABLE_SYMBOLS (bfd_plugin),
616 BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
617 BFD_JUMP_TABLE_WRITE (bfd_plugin),
618 BFD_JUMP_TABLE_LINK (bfd_plugin),
619 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
620
621 NULL,
622
623 NULL /* backend_data. */
624 };
625 #endif /* BFD_SUPPORTS_PLUGIN */
626